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Chris Lattneraf8d5812006-11-10 05:07:45 +00001//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===//
2//
3// The LLVM Compiler Infrastructure
4//
Chris Lattner5b12ab82007-12-29 19:59:25 +00005// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
Chris Lattneraf8d5812006-11-10 05:07:45 +00007//
8//===----------------------------------------------------------------------===//
9//
10// This file implements semantic analysis for statements.
11//
12//===----------------------------------------------------------------------===//
13
John McCall83024632010-08-25 22:03:47 +000014#include "clang/Sema/SemaInternal.h"
Chris Lattnerfc1c44a2007-08-23 05:46:52 +000015#include "clang/AST/ASTContext.h"
Fariborz Jahanian8b115b72013-01-09 23:04:56 +000016#include "clang/AST/ASTDiagnostic.h"
Richard Smith50e291e2018-01-02 23:52:42 +000017#include "clang/AST/ASTLambda.h"
John McCall03318c12011-11-11 03:57:31 +000018#include "clang/AST/CharUnits.h"
Aaron Ballman8aee642902015-04-08 00:05:29 +000019#include "clang/AST/CXXInheritance.h"
Daniel Dunbar6e8aa532008-08-11 05:35:13 +000020#include "clang/AST/DeclObjC.h"
Richard Trieu451a5db2012-04-30 18:01:30 +000021#include "clang/AST/EvaluatedExprVisitor.h"
Douglas Gregord0c22e02009-11-23 13:46:08 +000022#include "clang/AST/ExprCXX.h"
Chris Lattner2ba5ca92009-08-16 16:57:27 +000023#include "clang/AST/ExprObjC.h"
Nico Weber72889432014-09-06 01:25:55 +000024#include "clang/AST/RecursiveASTVisitor.h"
Chris Lattnerf0b64d72009-04-26 01:32:48 +000025#include "clang/AST/StmtCXX.h"
Chandler Carruth3a022472012-12-04 09:13:33 +000026#include "clang/AST/StmtObjC.h"
John McCall2351cb92010-04-06 22:24:14 +000027#include "clang/AST/TypeLoc.h"
Aaron Ballman8aee642902015-04-08 00:05:29 +000028#include "clang/AST/TypeOrdering.h"
Reid Kleckner9fe7f232015-07-07 00:36:30 +000029#include "clang/Basic/TargetInfo.h"
Chandler Carruth3a022472012-12-04 09:13:33 +000030#include "clang/Lex/Preprocessor.h"
31#include "clang/Sema/Initialization.h"
32#include "clang/Sema/Lookup.h"
33#include "clang/Sema/Scope.h"
34#include "clang/Sema/ScopeInfo.h"
Chris Lattner70a4e9b2011-02-21 21:40:33 +000035#include "llvm/ADT/ArrayRef.h"
Aaron Ballman8aee642902015-04-08 00:05:29 +000036#include "llvm/ADT/DenseMap.h"
Sebastian Redl63c4da02009-07-29 17:15:45 +000037#include "llvm/ADT/STLExtras.h"
Richard Trieu451a5db2012-04-30 18:01:30 +000038#include "llvm/ADT/SmallPtrSet.h"
Douglas Gregor0a9f4e02012-05-16 16:11:17 +000039#include "llvm/ADT/SmallString.h"
Sebastian Redl63c4da02009-07-29 17:15:45 +000040#include "llvm/ADT/SmallVector.h"
Erik Pilkingtonce26eac2016-04-26 20:55:48 +000041
Chris Lattneraf8d5812006-11-10 05:07:45 +000042using namespace clang;
John McCallaab3e412010-08-25 08:40:02 +000043using namespace sema;
Chris Lattneraf8d5812006-11-10 05:07:45 +000044
Richard Smith945f8d32013-01-14 22:39:08 +000045StmtResult Sema::ActOnExprStmt(ExprResult FE) {
46 if (FE.isInvalid())
47 return StmtError();
48
49 FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(),
50 /*DiscardedValue*/ true);
51 if (FE.isInvalid())
Douglas Gregora6e053e2010-12-15 01:34:56 +000052 return StmtError();
53
Chris Lattner903eb512008-07-25 23:18:17 +000054 // C99 6.8.3p2: The expression in an expression statement is evaluated as a
55 // void expression for its side effects. Conversion to void allows any
56 // operand, even incomplete types.
Sebastian Redl52f03ba2008-12-21 12:04:03 +000057
Chris Lattner903eb512008-07-25 23:18:17 +000058 // Same thing in for stmt first clause (when expr) and third clause.
Nikola Smiljanic03ff2592014-05-29 14:05:12 +000059 return StmtResult(FE.getAs<Stmt>());
Chris Lattner1ec5f562007-06-27 05:38:08 +000060}
61
62
John McCalleaef89b2013-03-22 02:10:40 +000063StmtResult Sema::ActOnExprStmtError() {
64 DiscardCleanupsInEvaluationContext();
65 return StmtError();
66}
67
Argyrios Kyrtzidisf7620e42011-04-27 05:04:02 +000068StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc,
Argyrios Kyrtzidis43ea78b2011-09-01 21:53:45 +000069 bool HasLeadingEmptyMacro) {
Nikola Smiljanic03ff2592014-05-29 14:05:12 +000070 return new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro);
Chris Lattner0f203a72007-05-28 01:45:28 +000071}
72
Chris Lattnerebb5c6c2011-02-18 01:27:55 +000073StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc,
74 SourceLocation EndLoc) {
Serge Pavlov9ddb76e2013-08-27 13:15:56 +000075 DeclGroupRef DG = dg.get();
Mike Stump11289f42009-09-09 15:08:12 +000076
Chris Lattnercbafe8d2009-04-12 20:13:14 +000077 // If we have an invalid decl, just return an error.
78 if (DG.isNull()) return StmtError();
Mike Stump11289f42009-09-09 15:08:12 +000079
Nikola Smiljanic03ff2592014-05-29 14:05:12 +000080 return new (Context) DeclStmt(DG, StartLoc, EndLoc);
Steve Naroff2a8ad182007-05-29 22:59:26 +000081}
Chris Lattneraf8d5812006-11-10 05:07:45 +000082
Fariborz Jahaniane774fa62009-11-19 22:12:37 +000083void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) {
Serge Pavlov9ddb76e2013-08-27 13:15:56 +000084 DeclGroupRef DG = dg.get();
Wei Panc4c76d12013-05-03 21:07:45 +000085
Douglas Gregor2eb1c572013-04-08 20:52:24 +000086 // If we don't have a declaration, or we have an invalid declaration,
87 // just return.
88 if (DG.isNull() || !DG.isSingleDecl())
89 return;
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +000090
Douglas Gregor2eb1c572013-04-08 20:52:24 +000091 Decl *decl = DG.getSingleDecl();
92 if (!decl || decl->isInvalidDecl())
93 return;
94
95 // Only variable declarations are permitted.
96 VarDecl *var = dyn_cast<VarDecl>(decl);
97 if (!var) {
98 Diag(decl->getLocation(), diag::err_non_variable_decl_in_for);
99 decl->setInvalidDecl();
100 return;
101 }
John McCall31168b02011-06-15 23:02:42 +0000102
John McCalld4631322011-06-17 06:42:21 +0000103 // foreach variables are never actually initialized in the way that
104 // the parser came up with.
Craig Topperc3ec1492014-05-26 06:22:03 +0000105 var->setInit(nullptr);
John McCall31168b02011-06-15 23:02:42 +0000106
John McCalld4631322011-06-17 06:42:21 +0000107 // In ARC, we don't need to retain the iteration variable of a fast
108 // enumeration loop. Rather than actually trying to catch that
109 // during declaration processing, we remove the consequences here.
David Blaikiebbafb8a2012-03-11 07:00:24 +0000110 if (getLangOpts().ObjCAutoRefCount) {
John McCalld4631322011-06-17 06:42:21 +0000111 QualType type = var->getType();
112
113 // Only do this if we inferred the lifetime. Inferred lifetime
114 // will show up as a local qualifier because explicit lifetime
115 // should have shown up as an AttributedType instead.
116 if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) {
117 // Add 'const' and mark the variable as pseudo-strong.
118 var->setType(type.withConst());
119 var->setARCPseudoStrong(true);
John McCall31168b02011-06-15 23:02:42 +0000120 }
121 }
Fariborz Jahaniane774fa62009-11-19 22:12:37 +0000122}
123
Adrian Prantl9fc8faf2018-05-09 01:00:01 +0000124/// Diagnose unused comparisons, both builtin and overloaded operators.
Richard Trieu99e1c952014-03-11 03:11:08 +0000125/// For '==' and '!=', suggest fixits for '=' or '|='.
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000126///
127/// Adding a cast to void (or other expression wrappers) will prevent the
128/// warning from firing.
Chandler Carruthe2669392011-08-17 09:34:37 +0000129static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) {
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000130 SourceLocation Loc;
Richard Smithc70f1d62017-12-14 15:16:18 +0000131 bool CanAssign;
132 enum { Equality, Inequality, Relational, ThreeWay } Kind;
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000133
134 if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) {
Richard Trieu99e1c952014-03-11 03:11:08 +0000135 if (!Op->isComparisonOp())
Chandler Carruthe2669392011-08-17 09:34:37 +0000136 return false;
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000137
Richard Smithc70f1d62017-12-14 15:16:18 +0000138 if (Op->getOpcode() == BO_EQ)
139 Kind = Equality;
140 else if (Op->getOpcode() == BO_NE)
141 Kind = Inequality;
142 else if (Op->getOpcode() == BO_Cmp)
143 Kind = ThreeWay;
144 else {
145 assert(Op->isRelationalOp());
146 Kind = Relational;
147 }
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000148 Loc = Op->getOperatorLoc();
Chandler Carruthe89ca5f2011-08-17 08:38:11 +0000149 CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue();
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000150 } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) {
Richard Trieu99e1c952014-03-11 03:11:08 +0000151 switch (Op->getOperator()) {
Richard Trieu99e1c952014-03-11 03:11:08 +0000152 case OO_EqualEqual:
Richard Smithc70f1d62017-12-14 15:16:18 +0000153 Kind = Equality;
154 break;
Richard Trieu99e1c952014-03-11 03:11:08 +0000155 case OO_ExclaimEqual:
Richard Smithc70f1d62017-12-14 15:16:18 +0000156 Kind = Inequality;
Richard Trieu99e1c952014-03-11 03:11:08 +0000157 break;
158 case OO_Less:
159 case OO_Greater:
160 case OO_GreaterEqual:
161 case OO_LessEqual:
Richard Smithc70f1d62017-12-14 15:16:18 +0000162 Kind = Relational;
Richard Trieu99e1c952014-03-11 03:11:08 +0000163 break;
Richard Smithc70f1d62017-12-14 15:16:18 +0000164 case OO_Spaceship:
165 Kind = ThreeWay;
166 break;
167 default:
168 return false;
Richard Trieu99e1c952014-03-11 03:11:08 +0000169 }
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000170
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000171 Loc = Op->getOperatorLoc();
Chandler Carruthe89ca5f2011-08-17 08:38:11 +0000172 CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue();
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000173 } else {
174 // Not a typo-prone comparison.
Chandler Carruthe2669392011-08-17 09:34:37 +0000175 return false;
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000176 }
177
178 // Suppress warnings when the operator, suspicious as it may be, comes from
179 // a macro expansion.
Matt Beaumont-Gayb1e71a72013-01-12 00:54:16 +0000180 if (S.SourceMgr.isMacroBodyExpansion(Loc))
Chandler Carruthe2669392011-08-17 09:34:37 +0000181 return false;
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000182
Chandler Carruthe2669392011-08-17 09:34:37 +0000183 S.Diag(Loc, diag::warn_unused_comparison)
Richard Smithc70f1d62017-12-14 15:16:18 +0000184 << (unsigned)Kind << E->getSourceRange();
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000185
Chandler Carruthe89ca5f2011-08-17 08:38:11 +0000186 // If the LHS is a plausible entity to assign to, provide a fixit hint to
187 // correct common typos.
Richard Smithc70f1d62017-12-14 15:16:18 +0000188 if (CanAssign) {
189 if (Kind == Inequality)
Chandler Carruthe89ca5f2011-08-17 08:38:11 +0000190 S.Diag(Loc, diag::note_inequality_comparison_to_or_assign)
191 << FixItHint::CreateReplacement(Loc, "|=");
Richard Smithc70f1d62017-12-14 15:16:18 +0000192 else if (Kind == Equality)
Chandler Carruthe89ca5f2011-08-17 08:38:11 +0000193 S.Diag(Loc, diag::note_equality_comparison_to_assign)
194 << FixItHint::CreateReplacement(Loc, "=");
195 }
Chandler Carruthe2669392011-08-17 09:34:37 +0000196
197 return true;
Chandler Carruthae51ecc2011-08-17 08:38:04 +0000198}
199
Anders Carlsson59a2ab92009-07-30 22:17:18 +0000200void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
Argyrios Kyrtzidis90963412010-09-19 21:21:10 +0000201 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S))
202 return DiagnoseUnusedExprResult(Label->getSubStmt());
203
Anders Carlsson5c5f1602009-07-30 22:39:03 +0000204 const Expr *E = dyn_cast_or_null<Expr>(S);
Anders Carlsson59a2ab92009-07-30 22:17:18 +0000205 if (!E)
206 return;
Aaron Ballman78ecb872014-10-16 20:13:28 +0000207
208 // If we are in an unevaluated expression context, then there can be no unused
209 // results because the results aren't expected to be used in the first place.
210 if (isUnevaluatedContext())
211 return;
212
Nico Weber0e631632015-10-27 19:47:40 +0000213 SourceLocation ExprLoc = E->IgnoreParenImpCasts()->getExprLoc();
Matt Beaumont-Gay1c417da2013-02-26 19:34:08 +0000214 // In most cases, we don't want to warn if the expression is written in a
215 // macro body, or if the macro comes from a system header. If the offending
216 // expression is a call to a function with the warn_unused_result attribute,
217 // we warn no matter the location. Because of the order in which the various
218 // checks need to happen, we factor out the macro-related test here.
Fangrui Song6907ce22018-07-30 19:24:48 +0000219 bool ShouldSuppress =
Matt Beaumont-Gay1c417da2013-02-26 19:34:08 +0000220 SourceMgr.isMacroBodyExpansion(ExprLoc) ||
221 SourceMgr.isInSystemMacro(ExprLoc);
Anders Carlsson59a2ab92009-07-30 22:17:18 +0000222
Eli Friedmanc11535c2012-05-24 00:47:05 +0000223 const Expr *WarnExpr;
Anders Carlsson59a2ab92009-07-30 22:17:18 +0000224 SourceLocation Loc;
225 SourceRange R1, R2;
Matt Beaumont-Gay978cca92013-01-17 02:06:08 +0000226 if (!E->isUnusedResultAWarning(WarnExpr, Loc, R1, R2, Context))
Anders Carlsson59a2ab92009-07-30 22:17:18 +0000227 return;
Mike Stump11289f42009-09-09 15:08:12 +0000228
Chris Lattner6dc7e572012-08-31 22:39:21 +0000229 // If this is a GNU statement expression expanded from a macro, it is probably
230 // unused because it is a function-like macro that can be used as either an
231 // expression or statement. Don't warn, because it is almost certainly a
232 // false positive.
233 if (isa<StmtExpr>(E) && Loc.isMacroID())
234 return;
235
Nico Weber0e631632015-10-27 19:47:40 +0000236 // Check if this is the UNREFERENCED_PARAMETER from the Microsoft headers.
237 // That macro is frequently used to suppress "unused parameter" warnings,
238 // but its implementation makes clang's -Wunused-value fire. Prevent this.
239 if (isa<ParenExpr>(E->IgnoreImpCasts()) && Loc.isMacroID()) {
240 SourceLocation SpellLoc = Loc;
241 if (findMacroSpelling(SpellLoc, "UNREFERENCED_PARAMETER"))
242 return;
243 }
244
Chris Lattner2ba5ca92009-08-16 16:57:27 +0000245 // Okay, we have an unused result. Depending on what the base expression is,
246 // we might want to make a more specific diagnostic. Check for one of these
247 // cases now.
248 unsigned DiagID = diag::warn_unused_expr;
Bill Wendling7c44da22018-10-31 03:48:47 +0000249 if (const FullExpr *Temps = dyn_cast<FullExpr>(E))
Douglas Gregor50dc2192010-02-11 22:55:30 +0000250 E = Temps->getSubExpr();
Chandler Carruthd05b3522011-02-21 00:56:56 +0000251 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E))
252 E = TempExpr->getSubExpr();
John McCallb7bd14f2010-12-02 01:19:52 +0000253
Chandler Carruthe2669392011-08-17 09:34:37 +0000254 if (DiagnoseUnusedComparison(*this, E))
255 return;
256
Eli Friedmanc11535c2012-05-24 00:47:05 +0000257 E = WarnExpr;
Chris Lattner1a6babf2009-10-13 04:53:48 +0000258 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
John McCallc493a732010-03-12 07:11:26 +0000259 if (E->getType()->isVoidType())
260 return;
261
Chris Lattner1a6babf2009-10-13 04:53:48 +0000262 // If the callee has attribute pure, const, or warn_unused_result, warn with
Matt Beaumont-Gay1c417da2013-02-26 19:34:08 +0000263 // a more specific message to make it clear what is happening. If the call
264 // is written in a macro body, only warn if it has the warn_unused_result
265 // attribute.
Nuno Lopes518e3702009-12-20 23:11:08 +0000266 if (const Decl *FD = CE->getCalleeDecl()) {
Aaron Ballmane7964782016-03-07 22:44:55 +0000267 if (const Attr *A = isa<FunctionDecl>(FD)
268 ? cast<FunctionDecl>(FD)->getUnusedResultAttr()
269 : FD->getAttr<WarnUnusedResultAttr>()) {
270 Diag(Loc, diag::warn_unused_result) << A << R1 << R2;
Chris Lattner1a6babf2009-10-13 04:53:48 +0000271 return;
272 }
Matt Beaumont-Gay1c417da2013-02-26 19:34:08 +0000273 if (ShouldSuppress)
274 return;
Aaron Ballman9ead1242013-12-19 02:39:40 +0000275 if (FD->hasAttr<PureAttr>()) {
Chris Lattner1a6babf2009-10-13 04:53:48 +0000276 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure";
277 return;
278 }
Aaron Ballman9ead1242013-12-19 02:39:40 +0000279 if (FD->hasAttr<ConstAttr>()) {
Chris Lattner1a6babf2009-10-13 04:53:48 +0000280 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const";
281 return;
282 }
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +0000283 }
Matt Beaumont-Gay1c417da2013-02-26 19:34:08 +0000284 } else if (ShouldSuppress)
285 return;
286
287 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
David Blaikiebbafb8a2012-03-11 07:00:24 +0000288 if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) {
John McCall31168b02011-06-15 23:02:42 +0000289 Diag(Loc, diag::err_arc_unused_init_message) << R1;
290 return;
291 }
Fariborz Jahanian5cab26d2010-03-30 18:22:15 +0000292 const ObjCMethodDecl *MD = ME->getMethodDecl();
Fariborz Jahanianac6b4ef2014-07-18 22:59:10 +0000293 if (MD) {
Aaron Ballmane7964782016-03-07 22:44:55 +0000294 if (const auto *A = MD->getAttr<WarnUnusedResultAttr>()) {
295 Diag(Loc, diag::warn_unused_result) << A << R1 << R2;
Fariborz Jahanianac6b4ef2014-07-18 22:59:10 +0000296 return;
297 }
Fariborz Jahanian5cab26d2010-03-30 18:22:15 +0000298 }
Ted Kremeneke65b0862012-03-06 20:05:56 +0000299 } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {
300 const Expr *Source = POE->getSyntacticForm();
301 if (isa<ObjCSubscriptRefExpr>(Source))
302 DiagID = diag::warn_unused_container_subscript_expr;
303 else
304 DiagID = diag::warn_unused_property_expr;
Douglas Gregorb33eed02010-04-16 22:09:46 +0000305 } else if (const CXXFunctionalCastExpr *FC
306 = dyn_cast<CXXFunctionalCastExpr>(E)) {
Daniel Jasper9c81a722017-03-27 16:29:41 +0000307 const Expr *E = FC->getSubExpr();
308 if (const CXXBindTemporaryExpr *TE = dyn_cast<CXXBindTemporaryExpr>(E))
309 E = TE->getSubExpr();
310 if (isa<CXXTemporaryObjectExpr>(E))
Douglas Gregorb33eed02010-04-16 22:09:46 +0000311 return;
Daniel Jasper9c81a722017-03-27 16:29:41 +0000312 if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(E))
313 if (const CXXRecordDecl *RD = CE->getType()->getAsCXXRecordDecl())
314 if (!RD->getAttr<WarnUnusedAttr>())
315 return;
Fariborz Jahanian5cab26d2010-03-30 18:22:15 +0000316 }
John McCall2351cb92010-04-06 22:24:14 +0000317 // Diagnose "(void*) blah" as a typo for "(void) blah".
318 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) {
319 TypeSourceInfo *TI = CE->getTypeInfoAsWritten();
320 QualType T = TI->getType();
321
322 // We really do want to use the non-canonical type here.
323 if (T == Context.VoidPtrTy) {
David Blaikie6adc78e2013-02-18 22:06:02 +0000324 PointerTypeLoc TL = TI->getTypeLoc().castAs<PointerTypeLoc>();
John McCall2351cb92010-04-06 22:24:14 +0000325
326 Diag(Loc, diag::warn_unused_voidptr)
327 << FixItHint::CreateRemoval(TL.getStarLoc());
328 return;
329 }
330 }
331
Eli Friedmanc11535c2012-05-24 00:47:05 +0000332 if (E->isGLValue() && E->getType().isVolatileQualified()) {
333 Diag(Loc, diag::warn_unused_volatile) << R1 << R2;
334 return;
335 }
336
Craig Topperc3ec1492014-05-26 06:22:03 +0000337 DiagRuntimeBehavior(Loc, nullptr, PDiag(DiagID) << R1 << R2);
Anders Carlsson59a2ab92009-07-30 22:17:18 +0000338}
339
Richard Smith6eb9b9e2018-02-03 00:44:57 +0000340void Sema::ActOnStartOfCompoundStmt(bool IsStmtExpr) {
341 PushCompoundScope(IsStmtExpr);
Dmitri Gribenko800ddf32012-02-14 22:14:32 +0000342}
343
344void Sema::ActOnFinishOfCompoundStmt() {
345 PopCompoundScope();
346}
347
348sema::CompoundScopeInfo &Sema::getCurCompoundScope() const {
349 return getCurFunction()->CompoundScopes.back();
350}
351
Robert Wilhelm27b2c9a32013-08-19 20:51:20 +0000352StmtResult Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
353 ArrayRef<Stmt *> Elts, bool isStmtExpr) {
354 const unsigned NumElts = Elts.size();
355
Chris Lattnerd864daf2007-08-27 04:29:41 +0000356 // If we're in C89 mode, check that we don't have any decls after stmts. If
357 // so, emit an extension diagnostic.
David Blaikiebbafb8a2012-03-11 07:00:24 +0000358 if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) {
Chris Lattnerd864daf2007-08-27 04:29:41 +0000359 // Note that __extension__ can be around a decl.
360 unsigned i = 0;
361 // Skip over all declarations.
362 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i)
363 /*empty*/;
364
365 // We found the end of the list or a statement. Scan for another declstmt.
366 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i)
367 /*empty*/;
Mike Stump11289f42009-09-09 15:08:12 +0000368
Chris Lattnerd864daf2007-08-27 04:29:41 +0000369 if (i != NumElts) {
Douglas Gregor6e6ad602009-01-20 01:17:11 +0000370 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin();
Chris Lattnerd864daf2007-08-27 04:29:41 +0000371 Diag(D->getLocation(), diag::ext_mixed_decls_code);
372 }
373 }
Chris Lattnercac27a52007-08-31 21:49:55 +0000374 // Warn about unused expressions in statements.
375 for (unsigned i = 0; i != NumElts; ++i) {
Anders Carlsson59a2ab92009-07-30 22:17:18 +0000376 // Ignore statements that are last in a statement expression.
377 if (isStmtExpr && i == NumElts - 1)
Chris Lattnercac27a52007-08-31 21:49:55 +0000378 continue;
Mike Stump11289f42009-09-09 15:08:12 +0000379
Anders Carlsson59a2ab92009-07-30 22:17:18 +0000380 DiagnoseUnusedExprResult(Elts[i]);
Chris Lattnercac27a52007-08-31 21:49:55 +0000381 }
Sebastian Redl52f03ba2008-12-21 12:04:03 +0000382
Dmitri Gribenko800ddf32012-02-14 22:14:32 +0000383 // Check for suspicious empty body (null statement) in `for' and `while'
384 // statements. Don't do anything for template instantiations, this just adds
385 // noise.
386 if (NumElts != 0 && !CurrentInstantiationScope &&
387 getCurCompoundScope().HasEmptyLoopBodies) {
388 for (unsigned i = 0; i != NumElts - 1; ++i)
389 DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]);
390 }
391
Benjamin Kramer07420902017-12-24 16:24:20 +0000392 return CompoundStmt::Create(Context, Elts, L, R);
Chris Lattneraf8d5812006-11-10 05:07:45 +0000393}
394
Richard Smithef6c43d2018-07-26 18:41:30 +0000395ExprResult
396Sema::ActOnCaseExpr(SourceLocation CaseLoc, ExprResult Val) {
397 if (!Val.get())
398 return Val;
399
400 if (DiagnoseUnexpandedParameterPack(Val.get()))
401 return ExprError();
402
403 // If we're not inside a switch, let the 'case' statement handling diagnose
404 // this. Just clean up after the expression as best we can.
405 if (!getCurFunction()->SwitchStack.empty()) {
406 Expr *CondExpr =
407 getCurFunction()->SwitchStack.back().getPointer()->getCond();
408 if (!CondExpr)
409 return ExprError();
410 QualType CondType = CondExpr->getType();
411
412 auto CheckAndFinish = [&](Expr *E) {
413 if (CondType->isDependentType() || E->isTypeDependent())
414 return ExprResult(E);
415
416 if (getLangOpts().CPlusPlus11) {
417 // C++11 [stmt.switch]p2: the constant-expression shall be a converted
418 // constant expression of the promoted type of the switch condition.
419 llvm::APSInt TempVal;
420 return CheckConvertedConstantExpression(E, CondType, TempVal,
421 CCEK_CaseValue);
422 }
423
424 ExprResult ER = E;
425 if (!E->isValueDependent())
426 ER = VerifyIntegerConstantExpression(E);
427 if (!ER.isInvalid())
428 ER = DefaultLvalueConversion(ER.get());
429 if (!ER.isInvalid())
430 ER = ImpCastExprToType(ER.get(), CondType, CK_IntegralCast);
431 return ER;
432 };
433
434 ExprResult Converted = CorrectDelayedTyposInExpr(Val, CheckAndFinish);
435 if (Converted.get() == Val.get())
436 Converted = CheckAndFinish(Val.get());
437 if (Converted.isInvalid())
438 return ExprError();
439 Val = Converted;
440 }
441
442 return ActOnFinishFullExpr(Val.get(), Val.get()->getExprLoc(), false,
443 getLangOpts().CPlusPlus11);
444}
445
John McCalldadc5752010-08-24 06:29:42 +0000446StmtResult
Richard Smithef6c43d2018-07-26 18:41:30 +0000447Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprResult LHSVal,
448 SourceLocation DotDotDotLoc, ExprResult RHSVal,
Chris Lattner34a22092009-03-04 04:23:07 +0000449 SourceLocation ColonLoc) {
Richard Smithef6c43d2018-07-26 18:41:30 +0000450 assert((LHSVal.isInvalid() || LHSVal.get()) && "missing LHS value");
451 assert((DotDotDotLoc.isInvalid() ? RHSVal.isUnset()
452 : RHSVal.isInvalid() || RHSVal.get()) &&
453 "missing RHS value");
Sebastian Redl1cbb59182008-12-28 16:13:43 +0000454
John McCallaab3e412010-08-25 08:40:02 +0000455 if (getCurFunction()->SwitchStack.empty()) {
Chris Lattner54f4d2b2007-07-23 17:05:23 +0000456 Diag(CaseLoc, diag::err_case_not_in_switch);
Chris Lattner34a22092009-03-04 04:23:07 +0000457 return StmtError();
Chris Lattner54f4d2b2007-07-23 17:05:23 +0000458 }
Chris Lattner35e287b2007-06-03 01:44:43 +0000459
Richard Smithef6c43d2018-07-26 18:41:30 +0000460 if (LHSVal.isInvalid() || RHSVal.isInvalid()) {
461 getCurFunction()->SwitchStack.back().setInt(true);
Kaelyn Takatab16e6322014-11-20 22:06:40 +0000462 return StmtError();
Richard Smithf8379a02012-01-18 23:55:52 +0000463 }
Ben Langmuir2e13dd62013-04-29 13:07:42 +0000464
Bruno Ricci5b30571752018-10-28 12:30:53 +0000465 auto *CS = CaseStmt::Create(Context, LHSVal.get(), RHSVal.get(),
466 CaseLoc, DotDotDotLoc, ColonLoc);
Richard Smithef6c43d2018-07-26 18:41:30 +0000467 getCurFunction()->SwitchStack.back().getPointer()->addSwitchCase(CS);
Nikola Smiljanic03ff2592014-05-29 14:05:12 +0000468 return CS;
Chris Lattneraf8d5812006-11-10 05:07:45 +0000469}
470
Chris Lattner34a22092009-03-04 04:23:07 +0000471/// ActOnCaseStmtBody - This installs a statement as the body of a case.
Aaron Ballmand9141742018-12-21 21:11:36 +0000472void Sema::ActOnCaseStmtBody(Stmt *S, Stmt *SubStmt) {
Chandler Carruth2b949c22011-08-18 02:04:29 +0000473 DiagnoseUnusedExprResult(SubStmt);
Aaron Ballmand9141742018-12-21 21:11:36 +0000474 cast<CaseStmt>(S)->setSubStmt(SubStmt);
Chris Lattner34a22092009-03-04 04:23:07 +0000475}
476
John McCalldadc5752010-08-24 06:29:42 +0000477StmtResult
Mike Stump11289f42009-09-09 15:08:12 +0000478Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
John McCallb268a282010-08-23 23:25:46 +0000479 Stmt *SubStmt, Scope *CurScope) {
Chandler Carruth2b949c22011-08-18 02:04:29 +0000480 DiagnoseUnusedExprResult(SubStmt);
481
John McCallaab3e412010-08-25 08:40:02 +0000482 if (getCurFunction()->SwitchStack.empty()) {
Chris Lattner39407372007-07-21 03:00:26 +0000483 Diag(DefaultLoc, diag::err_default_not_in_switch);
Nikola Smiljanic03ff2592014-05-29 14:05:12 +0000484 return SubStmt;
Chris Lattner39407372007-07-21 03:00:26 +0000485 }
Sebastian Redl1cbb59182008-12-28 16:13:43 +0000486
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000487 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt);
Richard Smithef6c43d2018-07-26 18:41:30 +0000488 getCurFunction()->SwitchStack.back().getPointer()->addSwitchCase(DS);
Nikola Smiljanic03ff2592014-05-29 14:05:12 +0000489 return DS;
Chris Lattneraf8d5812006-11-10 05:07:45 +0000490}
491
John McCalldadc5752010-08-24 06:29:42 +0000492StmtResult
Chris Lattnercab02a62011-02-17 20:34:02 +0000493Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl,
494 SourceLocation ColonLoc, Stmt *SubStmt) {
Chris Lattnerc8e630e2011-02-17 07:39:24 +0000495 // If the label was multiply defined, reject it now.
496 if (TheDecl->getStmt()) {
497 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName();
498 Diag(TheDecl->getLocation(), diag::note_previous_definition);
Nikola Smiljanic03ff2592014-05-29 14:05:12 +0000499 return SubStmt;
Chris Lattnere2473062007-05-28 06:28:18 +0000500 }
Sebastian Redl6a8002e2009-01-11 00:38:46 +0000501
Chris Lattnerc8e630e2011-02-17 07:39:24 +0000502 // Otherwise, things are good. Fill in the declaration and return it.
Chris Lattnerc8e630e2011-02-17 07:39:24 +0000503 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt);
504 TheDecl->setStmt(LS);
Abramo Bagnara598b9432012-10-15 21:07:44 +0000505 if (!TheDecl->isGnuLocal()) {
506 TheDecl->setLocStart(IdentLoc);
Ehsan Akhgari31097582014-09-22 02:21:54 +0000507 if (!TheDecl->isMSAsmLabel()) {
508 // Don't update the location of MS ASM labels. These will result in
509 // a diagnostic, and changing the location here will mess that up.
510 TheDecl->setLocation(IdentLoc);
511 }
Abramo Bagnara598b9432012-10-15 21:07:44 +0000512 }
Nikola Smiljanic03ff2592014-05-29 14:05:12 +0000513 return LS;
Chris Lattneraf8d5812006-11-10 05:07:45 +0000514}
515
Richard Smithc202b282012-04-14 00:33:13 +0000516StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc,
Alexander Kornienko20f6fc62012-07-09 10:04:07 +0000517 ArrayRef<const Attr*> Attrs,
Richard Smithc202b282012-04-14 00:33:13 +0000518 Stmt *SubStmt) {
Alexander Kornienko20f6fc62012-07-09 10:04:07 +0000519 // Fill in the declaration and return it.
520 AttributedStmt *LS = AttributedStmt::Create(Context, AttrLoc, Attrs, SubStmt);
Nikola Smiljanic03ff2592014-05-29 14:05:12 +0000521 return LS;
Richard Smithc202b282012-04-14 00:33:13 +0000522}
523
Richard Trieufaca2d82016-02-18 23:58:40 +0000524namespace {
525class CommaVisitor : public EvaluatedExprVisitor<CommaVisitor> {
526 typedef EvaluatedExprVisitor<CommaVisitor> Inherited;
527 Sema &SemaRef;
528public:
529 CommaVisitor(Sema &SemaRef) : Inherited(SemaRef.Context), SemaRef(SemaRef) {}
530 void VisitBinaryOperator(BinaryOperator *E) {
531 if (E->getOpcode() == BO_Comma)
532 SemaRef.DiagnoseCommaOperator(E->getLHS(), E->getExprLoc());
533 EvaluatedExprVisitor<CommaVisitor>::VisitBinaryOperator(E);
534 }
535};
536}
537
John McCalldadc5752010-08-24 06:29:42 +0000538StmtResult
Richard Smithc7a05a92016-06-29 21:17:59 +0000539Sema::ActOnIfStmt(SourceLocation IfLoc, bool IsConstexpr, Stmt *InitStmt,
540 ConditionResult Cond,
Argyrios Kyrtzidisde2bdf62010-11-20 02:04:01 +0000541 Stmt *thenStmt, SourceLocation ElseLoc,
542 Stmt *elseStmt) {
Richard Smithb130fe72016-06-23 19:16:49 +0000543 if (Cond.isInvalid())
544 Cond = ConditionResult(
545 *this, nullptr,
546 MakeFullExpr(new (Context) OpaqueValueExpr(SourceLocation(),
547 Context.BoolTy, VK_RValue),
548 IfLoc),
549 false);
Anders Carlssondb83d772007-10-10 20:50:11 +0000550
Richard Smithb130fe72016-06-23 19:16:49 +0000551 Expr *CondExpr = Cond.get().second;
Richard Trieuf3713802018-10-25 01:08:00 +0000552 // Only call the CommaVisitor when not C89 due to differences in scope flags.
553 if ((getLangOpts().C99 || getLangOpts().CPlusPlus) &&
554 !Diags.isIgnored(diag::warn_comma_operator, CondExpr->getExprLoc()))
Richard Smithb130fe72016-06-23 19:16:49 +0000555 CommaVisitor(*this).Visit(CondExpr);
556
Hans Wennborg59ad1502017-11-20 17:48:54 +0000557 if (!elseStmt)
Stephen Kelly1c301dc2018-08-09 21:09:38 +0000558 DiagnoseEmptyStmtBody(CondExpr->getEndLoc(), thenStmt,
Hans Wennborg95419752017-11-20 17:38:16 +0000559 diag::warn_empty_if_body);
Richard Smithb130fe72016-06-23 19:16:49 +0000560
Richard Smitha547eb22016-07-14 00:11:03 +0000561 return BuildIfStmt(IfLoc, IsConstexpr, InitStmt, Cond, thenStmt, ElseLoc,
562 elseStmt);
Richard Smithb130fe72016-06-23 19:16:49 +0000563}
564
565StmtResult Sema::BuildIfStmt(SourceLocation IfLoc, bool IsConstexpr,
Richard Smitha547eb22016-07-14 00:11:03 +0000566 Stmt *InitStmt, ConditionResult Cond,
567 Stmt *thenStmt, SourceLocation ElseLoc,
568 Stmt *elseStmt) {
Richard Smithb130fe72016-06-23 19:16:49 +0000569 if (Cond.isInvalid())
570 return StmtError();
571
Erik Pilkington5cd57172016-08-16 17:44:11 +0000572 if (IsConstexpr || isa<ObjCAvailabilityCheckExpr>(Cond.get().second))
Reid Kleckner87a31802018-03-12 21:43:02 +0000573 setFunctionHasBranchProtectedScope();
Richard Smith03a4aa32016-06-23 19:02:52 +0000574
575 DiagnoseUnusedExprResult(thenStmt);
Richard Smith03a4aa32016-06-23 19:02:52 +0000576 DiagnoseUnusedExprResult(elseStmt);
577
Bruno Riccib1cc94b2018-10-27 21:12:20 +0000578 return IfStmt::Create(Context, IfLoc, IsConstexpr, InitStmt, Cond.get().first,
579 Cond.get().second, thenStmt, ElseLoc, elseStmt);
Chris Lattneraf8d5812006-11-10 05:07:45 +0000580}
Steve Naroff86272ea2007-05-29 02:14:17 +0000581
Chris Lattner67998452007-08-23 18:29:20 +0000582namespace {
583 struct CaseCompareFunctor {
584 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
585 const llvm::APSInt &RHS) {
586 return LHS.first < RHS;
587 }
Chris Lattner1463cca2007-09-03 18:31:57 +0000588 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
589 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
590 return LHS.first < RHS.first;
591 }
Chris Lattner67998452007-08-23 18:29:20 +0000592 bool operator()(const llvm::APSInt &LHS,
593 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
594 return LHS < RHS.first;
595 }
596 };
Alexander Kornienkoab9db512015-06-22 23:07:51 +0000597}
Chris Lattner67998452007-08-23 18:29:20 +0000598
Chris Lattner4b2ff022007-09-21 18:15:22 +0000599/// CmpCaseVals - Comparison predicate for sorting case values.
600///
601static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs,
602 const std::pair<llvm::APSInt, CaseStmt*>& rhs) {
603 if (lhs.first < rhs.first)
604 return true;
605
606 if (lhs.first == rhs.first &&
607 lhs.second->getCaseLoc().getRawEncoding()
608 < rhs.second->getCaseLoc().getRawEncoding())
609 return true;
610 return false;
611}
612
Douglas Gregorbd6839732010-02-08 22:24:16 +0000613/// CmpEnumVals - Comparison predicate for sorting enumeration values.
614///
615static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
616 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
617{
618 return lhs.first < rhs.first;
619}
620
621/// EqEnumVals - Comparison preficate for uniqing enumeration values.
622///
623static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
624 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
625{
626 return lhs.first == rhs.first;
627}
628
Chris Lattnera96d4272009-10-16 16:45:22 +0000629/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of
630/// potentially integral-promoted expression @p expr.
Gabor Horvath64c32412017-08-09 08:57:09 +0000631static QualType GetTypeBeforeIntegralPromotion(const Expr *&E) {
Bill Wendling7c44da22018-10-31 03:48:47 +0000632 if (const auto *FE = dyn_cast<FullExpr>(E))
633 E = FE->getSubExpr();
Gabor Horvath64c32412017-08-09 08:57:09 +0000634 while (const auto *ImpCast = dyn_cast<ImplicitCastExpr>(E)) {
635 if (ImpCast->getCastKind() != CK_IntegralCast) break;
636 E = ImpCast->getSubExpr();
Chris Lattnera96d4272009-10-16 16:45:22 +0000637 }
Gabor Horvath64c32412017-08-09 08:57:09 +0000638 return E->getType();
Chris Lattnera96d4272009-10-16 16:45:22 +0000639}
640
Richard Smith03a4aa32016-06-23 19:02:52 +0000641ExprResult Sema::CheckSwitchCondition(SourceLocation SwitchLoc, Expr *Cond) {
Douglas Gregore2b37442012-05-04 22:38:52 +0000642 class SwitchConvertDiagnoser : public ICEConvertDiagnoser {
643 Expr *Cond;
Chad Rosiercc6a9082012-06-20 18:51:04 +0000644
Douglas Gregore2b37442012-05-04 22:38:52 +0000645 public:
646 SwitchConvertDiagnoser(Expr *Cond)
Richard Smithccc11812013-05-21 19:05:48 +0000647 : ICEConvertDiagnoser(/*AllowScopedEnumerations*/true, false, true),
648 Cond(Cond) {}
Chad Rosiercc6a9082012-06-20 18:51:04 +0000649
Craig Toppere14c0f82014-03-12 04:55:44 +0000650 SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
651 QualType T) override {
Douglas Gregore2b37442012-05-04 22:38:52 +0000652 return S.Diag(Loc, diag::err_typecheck_statement_requires_integer) << T;
653 }
Chad Rosiercc6a9082012-06-20 18:51:04 +0000654
Craig Toppere14c0f82014-03-12 04:55:44 +0000655 SemaDiagnosticBuilder diagnoseIncomplete(
656 Sema &S, SourceLocation Loc, QualType T) override {
Douglas Gregore2b37442012-05-04 22:38:52 +0000657 return S.Diag(Loc, diag::err_switch_incomplete_class_type)
658 << T << Cond->getSourceRange();
659 }
Chad Rosiercc6a9082012-06-20 18:51:04 +0000660
Craig Toppere14c0f82014-03-12 04:55:44 +0000661 SemaDiagnosticBuilder diagnoseExplicitConv(
662 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
Douglas Gregore2b37442012-05-04 22:38:52 +0000663 return S.Diag(Loc, diag::err_switch_explicit_conversion) << T << ConvTy;
664 }
Chad Rosiercc6a9082012-06-20 18:51:04 +0000665
Craig Toppere14c0f82014-03-12 04:55:44 +0000666 SemaDiagnosticBuilder noteExplicitConv(
667 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
Douglas Gregore2b37442012-05-04 22:38:52 +0000668 return S.Diag(Conv->getLocation(), diag::note_switch_conversion)
669 << ConvTy->isEnumeralType() << ConvTy;
670 }
Chad Rosiercc6a9082012-06-20 18:51:04 +0000671
Craig Toppere14c0f82014-03-12 04:55:44 +0000672 SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
673 QualType T) override {
Douglas Gregore2b37442012-05-04 22:38:52 +0000674 return S.Diag(Loc, diag::err_switch_multiple_conversions) << T;
675 }
Chad Rosiercc6a9082012-06-20 18:51:04 +0000676
Craig Toppere14c0f82014-03-12 04:55:44 +0000677 SemaDiagnosticBuilder noteAmbiguous(
678 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
Douglas Gregore2b37442012-05-04 22:38:52 +0000679 return S.Diag(Conv->getLocation(), diag::note_switch_conversion)
680 << ConvTy->isEnumeralType() << ConvTy;
681 }
Chad Rosiercc6a9082012-06-20 18:51:04 +0000682
Craig Toppere14c0f82014-03-12 04:55:44 +0000683 SemaDiagnosticBuilder diagnoseConversion(
684 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
Richard Smithccc11812013-05-21 19:05:48 +0000685 llvm_unreachable("conversion functions are permitted");
Douglas Gregore2b37442012-05-04 22:38:52 +0000686 }
687 } SwitchDiagnoser(Cond);
688
Richard Smith03a4aa32016-06-23 19:02:52 +0000689 ExprResult CondResult =
Richard Smithccc11812013-05-21 19:05:48 +0000690 PerformContextualImplicitConversion(SwitchLoc, Cond, SwitchDiagnoser);
Richard Smith03a4aa32016-06-23 19:02:52 +0000691 if (CondResult.isInvalid())
692 return ExprError();
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +0000693
Richard Smithef6c43d2018-07-26 18:41:30 +0000694 // FIXME: PerformContextualImplicitConversion doesn't always tell us if it
695 // failed and produced a diagnostic.
696 Cond = CondResult.get();
697 if (!Cond->isTypeDependent() &&
698 !Cond->getType()->isIntegralOrEnumerationType())
699 return ExprError();
700
John McCall5939b162011-08-06 07:30:58 +0000701 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr.
Richard Smithef6c43d2018-07-26 18:41:30 +0000702 return UsualUnaryConversions(Cond);
Richard Smith03a4aa32016-06-23 19:02:52 +0000703}
John McCall5939b162011-08-06 07:30:58 +0000704
Richard Smithc7a05a92016-06-29 21:17:59 +0000705StmtResult Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc,
706 Stmt *InitStmt, ConditionResult Cond) {
Richard Smithef6c43d2018-07-26 18:41:30 +0000707 Expr *CondExpr = Cond.get().second;
708 assert((Cond.isInvalid() || CondExpr) && "switch with no condition");
709
710 if (CondExpr && !CondExpr->isTypeDependent()) {
711 // We have already converted the expression to an integral or enumeration
712 // type, when we parsed the switch condition. If we don't have an
713 // appropriate type now, enter the switch scope but remember that it's
714 // invalid.
715 assert(CondExpr->getType()->isIntegralOrEnumerationType() &&
716 "invalid condition type");
717 if (CondExpr->isKnownToHaveBooleanValue()) {
718 // switch(bool_expr) {...} is often a programmer error, e.g.
719 // switch(n && mask) { ... } // Doh - should be "n & mask".
720 // One can always use an if statement instead of switch(bool_expr).
721 Diag(SwitchLoc, diag::warn_bool_switch_condition)
722 << CondExpr->getSourceRange();
723 }
724 }
John McCalla95172b2010-08-01 00:26:45 +0000725
Reid Kleckner87a31802018-03-12 21:43:02 +0000726 setFunctionHasBranchIntoScope();
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +0000727
Bruno Riccie2806f82018-10-29 16:12:37 +0000728 auto *SS = SwitchStmt::Create(Context, InitStmt, Cond.get().first, CondExpr);
Richard Smithef6c43d2018-07-26 18:41:30 +0000729 getCurFunction()->SwitchStack.push_back(
730 FunctionScopeInfo::SwitchInfo(SS, false));
Nikola Smiljanic03ff2592014-05-29 14:05:12 +0000731 return SS;
Chris Lattner8fd2d012010-01-24 01:50:29 +0000732}
733
Gabor Greif16e02862010-10-01 22:05:14 +0000734static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) {
Richard Smith077d0832014-08-04 00:40:48 +0000735 Val = Val.extOrTrunc(BitWidth);
Gabor Greif16e02862010-10-01 22:05:14 +0000736 Val.setIsSigned(IsSigned);
737}
738
Richard Smith077d0832014-08-04 00:40:48 +0000739/// Check the specified case value is in range for the given unpromoted switch
740/// type.
741static void checkCaseValue(Sema &S, SourceLocation Loc, const llvm::APSInt &Val,
742 unsigned UnpromotedWidth, bool UnpromotedSign) {
Richard Smithef6c43d2018-07-26 18:41:30 +0000743 // In C++11 onwards, this is checked by the language rules.
744 if (S.getLangOpts().CPlusPlus11)
745 return;
746
Richard Smith077d0832014-08-04 00:40:48 +0000747 // If the case value was signed and negative and the switch expression is
748 // unsigned, don't bother to warn: this is implementation-defined behavior.
749 // FIXME: Introduce a second, default-ignored warning for this case?
750 if (UnpromotedWidth < Val.getBitWidth()) {
751 llvm::APSInt ConvVal(Val);
752 AdjustAPSInt(ConvVal, UnpromotedWidth, UnpromotedSign);
753 AdjustAPSInt(ConvVal, Val.getBitWidth(), Val.isSigned());
754 // FIXME: Use different diagnostics for overflow in conversion to promoted
755 // type versus "switch expression cannot have this value". Use proper
756 // IntRange checking rather than just looking at the unpromoted type here.
757 if (ConvVal != Val)
758 S.Diag(Loc, diag::warn_case_value_overflow) << Val.toString(10)
759 << ConvVal.toString(10);
760 }
761}
762
Alexis Hunt724f14e2014-11-28 00:53:20 +0000763typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> EnumValsTy;
764
Dmitri Gribenko58683752013-12-05 22:52:07 +0000765/// Returns true if we should emit a diagnostic about this case expression not
766/// being a part of the enum used in the switch controlling expression.
Alexis Hunt724f14e2014-11-28 00:53:20 +0000767static bool ShouldDiagnoseSwitchCaseNotInEnum(const Sema &S,
Dmitri Gribenko58683752013-12-05 22:52:07 +0000768 const EnumDecl *ED,
Alexis Hunt724f14e2014-11-28 00:53:20 +0000769 const Expr *CaseExpr,
770 EnumValsTy::iterator &EI,
771 EnumValsTy::iterator &EIEnd,
772 const llvm::APSInt &Val) {
Akira Hatanaka3c268af2017-03-21 02:23:00 +0000773 if (!ED->isClosed())
774 return false;
775
Alexis Hunt724f14e2014-11-28 00:53:20 +0000776 if (const DeclRefExpr *DRE =
777 dyn_cast<DeclRefExpr>(CaseExpr->IgnoreParenImpCasts())) {
Dmitri Gribenko58683752013-12-05 22:52:07 +0000778 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
Dmitri Gribenko58683752013-12-05 22:52:07 +0000779 QualType VarType = VD->getType();
Alexis Hunt724f14e2014-11-28 00:53:20 +0000780 QualType EnumType = S.Context.getTypeDeclType(ED);
781 if (VD->hasGlobalStorage() && VarType.isConstQualified() &&
782 S.Context.hasSameUnqualifiedType(EnumType, VarType))
Dmitri Gribenko58683752013-12-05 22:52:07 +0000783 return false;
784 }
785 }
Alexis Hunt724f14e2014-11-28 00:53:20 +0000786
Akira Hatanaka3c268af2017-03-21 02:23:00 +0000787 if (ED->hasAttr<FlagEnumAttr>())
Alexis Hunt724f14e2014-11-28 00:53:20 +0000788 return !S.IsValueInFlagEnum(ED, Val, false);
Alexis Hunt724f14e2014-11-28 00:53:20 +0000789
Akira Hatanaka3c268af2017-03-21 02:23:00 +0000790 while (EI != EIEnd && EI->first < Val)
791 EI++;
792
793 if (EI != EIEnd && EI->first == Val)
794 return false;
Alexis Hunt724f14e2014-11-28 00:53:20 +0000795
Dmitri Gribenko58683752013-12-05 22:52:07 +0000796 return true;
797}
798
Gabor Horvath64c32412017-08-09 08:57:09 +0000799static void checkEnumTypesInSwitchStmt(Sema &S, const Expr *Cond,
800 const Expr *Case) {
Richard Smithef6c43d2018-07-26 18:41:30 +0000801 QualType CondType = Cond->getType();
Gabor Horvath64c32412017-08-09 08:57:09 +0000802 QualType CaseType = Case->getType();
803
804 const EnumType *CondEnumType = CondType->getAs<EnumType>();
805 const EnumType *CaseEnumType = CaseType->getAs<EnumType>();
806 if (!CondEnumType || !CaseEnumType)
807 return;
808
Gabor Horvathb57e2642017-08-09 12:34:58 +0000809 // Ignore anonymous enums.
Richard Trieu285c9362017-09-09 00:25:05 +0000810 if (!CondEnumType->getDecl()->getIdentifier() &&
811 !CondEnumType->getDecl()->getTypedefNameForAnonDecl())
Gabor Horvathb57e2642017-08-09 12:34:58 +0000812 return;
Richard Trieu285c9362017-09-09 00:25:05 +0000813 if (!CaseEnumType->getDecl()->getIdentifier() &&
814 !CaseEnumType->getDecl()->getTypedefNameForAnonDecl())
Gabor Horvathb57e2642017-08-09 12:34:58 +0000815 return;
816
Gabor Horvath64c32412017-08-09 08:57:09 +0000817 if (S.Context.hasSameUnqualifiedType(CondType, CaseType))
818 return;
819
Gabor Horvath0284a202017-08-09 20:56:43 +0000820 S.Diag(Case->getExprLoc(), diag::warn_comparison_of_mixed_enum_types_switch)
Gabor Horvath64c32412017-08-09 08:57:09 +0000821 << CondType << CaseType << Cond->getSourceRange()
822 << Case->getSourceRange();
823}
824
John McCalldadc5752010-08-24 06:29:42 +0000825StmtResult
John McCallb268a282010-08-23 23:25:46 +0000826Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
827 Stmt *BodyStmt) {
828 SwitchStmt *SS = cast<SwitchStmt>(Switch);
Richard Smithef6c43d2018-07-26 18:41:30 +0000829 bool CaseListIsIncomplete = getCurFunction()->SwitchStack.back().getInt();
830 assert(SS == getCurFunction()->SwitchStack.back().getPointer() &&
John McCallaab3e412010-08-25 08:40:02 +0000831 "switch stack missing push/pop!");
Sebastian Redl6a8002e2009-01-11 00:38:46 +0000832
David Majnemer418ad3f2014-12-15 07:46:12 +0000833 getCurFunction()->SwitchStack.pop_back();
834
Serge Pavlov921c2ba2014-05-21 14:48:43 +0000835 if (!BodyStmt) return StmtError();
Steve Naroff42a350a2007-09-01 21:08:38 +0000836 SS->setBody(BodyStmt, SwitchLoc);
Anders Carlsson51873c22007-07-22 07:07:56 +0000837
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000838 Expr *CondExpr = SS->getCond();
John McCall5939b162011-08-06 07:30:58 +0000839 if (!CondExpr) return StmtError();
840
841 QualType CondType = CondExpr->getType();
842
Chris Lattnera96d4272009-10-16 16:45:22 +0000843 // C++ 6.4.2.p2:
844 // Integral promotions are performed (on the switch condition).
845 //
846 // A case value unrepresentable by the original switch condition
847 // type (before the promotion) doesn't make sense, even when it can
848 // be represented by the promoted type. Therefore we need to find
849 // the pre-promotion type of the switch condition.
Richard Smithef6c43d2018-07-26 18:41:30 +0000850 const Expr *CondExprBeforePromotion = CondExpr;
851 QualType CondTypeBeforePromotion =
852 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion);
Sebastian Redl6a8002e2009-01-11 00:38:46 +0000853
Richard Smith077d0832014-08-04 00:40:48 +0000854 // Get the bitwidth of the switched-on value after promotions. We must
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000855 // convert the integer case values to this width before comparison.
Mike Stump11289f42009-09-09 15:08:12 +0000856 bool HasDependentValue
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000857 = CondExpr->isTypeDependent() || CondExpr->isValueDependent();
Richard Smith077d0832014-08-04 00:40:48 +0000858 unsigned CondWidth = HasDependentValue ? 0 : Context.getIntWidth(CondType);
859 bool CondIsSigned = CondType->isSignedIntegerOrEnumerationType();
860
861 // Get the width and signedness that the condition might actually have, for
862 // warning purposes.
863 // FIXME: Grab an IntRange for the condition rather than using the unpromoted
864 // type.
865 unsigned CondWidthBeforePromotion
Chris Lattnerabcf38a2011-02-24 07:31:28 +0000866 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion);
Richard Smith077d0832014-08-04 00:40:48 +0000867 bool CondIsSignedBeforePromotion
Douglas Gregor6ab2fa82011-05-20 16:38:50 +0000868 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType();
Mike Stump11289f42009-09-09 15:08:12 +0000869
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000870 // Accumulate all of the case values in a vector so that we can sort them
871 // and detect duplicates. This vector contains the APInt for the case after
872 // it has been converted to the condition type.
Chris Lattner0e62c1c2011-07-23 10:55:15 +0000873 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy;
Chris Lattner67998452007-08-23 18:29:20 +0000874 CaseValsTy CaseVals;
Mike Stump11289f42009-09-09 15:08:12 +0000875
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000876 // Keep track of any GNU case ranges we see. The APSInt is the low value.
Douglas Gregorbd6839732010-02-08 22:24:16 +0000877 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy;
878 CaseRangesTy CaseRanges;
Mike Stump11289f42009-09-09 15:08:12 +0000879
Craig Topperc3ec1492014-05-26 06:22:03 +0000880 DefaultStmt *TheDefaultStmt = nullptr;
Mike Stump11289f42009-09-09 15:08:12 +0000881
Chris Lattner10cb5e52007-08-23 06:23:56 +0000882 bool CaseListIsErroneous = false;
Mike Stump11289f42009-09-09 15:08:12 +0000883
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000884 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue;
Anders Carlsson51873c22007-07-22 07:07:56 +0000885 SC = SC->getNextSwitchCase()) {
Mike Stump11289f42009-09-09 15:08:12 +0000886
Anders Carlsson51873c22007-07-22 07:07:56 +0000887 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) {
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000888 if (TheDefaultStmt) {
889 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined);
Chris Lattner0369c572008-11-23 23:12:31 +0000890 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev);
Sebastian Redl6a8002e2009-01-11 00:38:46 +0000891
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000892 // FIXME: Remove the default statement from the switch block so that
Mike Stump87c57ac2009-05-16 07:39:55 +0000893 // we'll return a valid AST. This requires recursing down the AST and
894 // finding it, not something we are set up to do right now. For now,
895 // just lop the entire switch stmt out of the AST.
Chris Lattner10cb5e52007-08-23 06:23:56 +0000896 CaseListIsErroneous = true;
Anders Carlsson51873c22007-07-22 07:07:56 +0000897 }
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000898 TheDefaultStmt = DS;
Mike Stump11289f42009-09-09 15:08:12 +0000899
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000900 } else {
901 CaseStmt *CS = cast<CaseStmt>(SC);
Mike Stump11289f42009-09-09 15:08:12 +0000902
Chris Lattnera65e1f32008-01-16 19:17:22 +0000903 Expr *Lo = CS->getLHS();
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000904
Richard Smithef6c43d2018-07-26 18:41:30 +0000905 if (Lo->isValueDependent()) {
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000906 HasDependentValue = true;
907 break;
908 }
Mike Stump11289f42009-09-09 15:08:12 +0000909
Richard Smithef6c43d2018-07-26 18:41:30 +0000910 // We already verified that the expression has a constant value;
911 // get that value (prior to conversions).
912 const Expr *LoBeforePromotion = Lo;
913 GetTypeBeforeIntegralPromotion(LoBeforePromotion);
914 llvm::APSInt LoVal = LoBeforePromotion->EvaluateKnownConstInt(Context);
Richard Smithf8379a02012-01-18 23:55:52 +0000915
Richard Smith077d0832014-08-04 00:40:48 +0000916 // Check the unconverted value is within the range of possible values of
917 // the switch expression.
Stephen Kellyf2ceec42018-08-09 21:08:08 +0000918 checkCaseValue(*this, Lo->getBeginLoc(), LoVal, CondWidthBeforePromotion,
919 CondIsSignedBeforePromotion);
Richard Smith077d0832014-08-04 00:40:48 +0000920
Richard Smithef6c43d2018-07-26 18:41:30 +0000921 // FIXME: This duplicates the check performed for warn_not_in_enum below.
922 checkEnumTypesInSwitchStmt(*this, CondExprBeforePromotion,
923 LoBeforePromotion);
924
Richard Smith077d0832014-08-04 00:40:48 +0000925 // Convert the value to the same width/sign as the condition.
926 AdjustAPSInt(LoVal, CondWidth, CondIsSigned);
Anders Carlsson51873c22007-07-22 07:07:56 +0000927
Chris Lattner10cb5e52007-08-23 06:23:56 +0000928 // If this is a case range, remember it in CaseRanges, otherwise CaseVals.
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000929 if (CS->getRHS()) {
Richard Smithef6c43d2018-07-26 18:41:30 +0000930 if (CS->getRHS()->isValueDependent()) {
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000931 HasDependentValue = true;
932 break;
933 }
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000934 CaseRanges.push_back(std::make_pair(LoVal, CS));
Mike Stump11289f42009-09-09 15:08:12 +0000935 } else
Chris Lattner10cb5e52007-08-23 06:23:56 +0000936 CaseVals.push_back(std::make_pair(LoVal, CS));
Chris Lattnerfc1c44a2007-08-23 05:46:52 +0000937 }
938 }
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000939
940 if (!HasDependentValue) {
John McCalld3dfbd62010-05-18 03:19:21 +0000941 // If we don't have a default statement, check whether the
942 // condition is constant.
943 llvm::APSInt ConstantCondValue;
944 bool HasConstantCond = false;
John McCalld3dfbd62010-05-18 03:19:21 +0000945 if (!HasDependentValue && !TheDefaultStmt) {
Fangrui Song407659a2018-11-30 23:41:18 +0000946 Expr::EvalResult Result;
947 HasConstantCond = CondExpr->EvaluateAsInt(Result, Context,
Richard Smith077d0832014-08-04 00:40:48 +0000948 Expr::SE_AllowSideEffects);
Fangrui Song407659a2018-11-30 23:41:18 +0000949 if (Result.Val.isInt())
950 ConstantCondValue = Result.Val.getInt();
Richard Smith5fab0c92011-12-28 19:48:30 +0000951 assert(!HasConstantCond ||
952 (ConstantCondValue.getBitWidth() == CondWidth &&
953 ConstantCondValue.isSigned() == CondIsSigned));
John McCalld3dfbd62010-05-18 03:19:21 +0000954 }
Richard Smith5fab0c92011-12-28 19:48:30 +0000955 bool ShouldCheckConstantCond = HasConstantCond;
John McCalld3dfbd62010-05-18 03:19:21 +0000956
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000957 // Sort all the scalar case values so we can easily detect duplicates.
958 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals);
959
960 if (!CaseVals.empty()) {
John McCalld3dfbd62010-05-18 03:19:21 +0000961 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) {
962 if (ShouldCheckConstantCond &&
963 CaseVals[i].first == ConstantCondValue)
964 ShouldCheckConstantCond = false;
965
966 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) {
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000967 // If we have a duplicate, report it.
Douglas Gregor9841df62012-05-16 05:32:58 +0000968 // First, determine if either case value has a name
969 StringRef PrevString, CurrString;
970 Expr *PrevCase = CaseVals[i-1].second->getLHS()->IgnoreParenCasts();
971 Expr *CurrCase = CaseVals[i].second->getLHS()->IgnoreParenCasts();
972 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(PrevCase)) {
973 PrevString = DeclRef->getDecl()->getName();
974 }
975 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(CurrCase)) {
976 CurrString = DeclRef->getDecl()->getName();
977 }
Dmitri Gribenkof8579502013-01-12 19:30:44 +0000978 SmallString<16> CaseValStr;
Douglas Gregor0a9f4e02012-05-16 16:11:17 +0000979 CaseVals[i-1].first.toString(CaseValStr);
Douglas Gregor9841df62012-05-16 05:32:58 +0000980
981 if (PrevString == CurrString)
Stephen Kellyf2ceec42018-08-09 21:08:08 +0000982 Diag(CaseVals[i].second->getLHS()->getBeginLoc(),
983 diag::err_duplicate_case)
984 << (PrevString.empty() ? StringRef(CaseValStr) : PrevString);
Douglas Gregor9841df62012-05-16 05:32:58 +0000985 else
Stephen Kellyf2ceec42018-08-09 21:08:08 +0000986 Diag(CaseVals[i].second->getLHS()->getBeginLoc(),
987 diag::err_duplicate_case_differing_expr)
988 << (PrevString.empty() ? StringRef(CaseValStr) : PrevString)
989 << (CurrString.empty() ? StringRef(CaseValStr) : CurrString)
990 << CaseValStr;
Douglas Gregor9841df62012-05-16 05:32:58 +0000991
Stephen Kellyf2ceec42018-08-09 21:08:08 +0000992 Diag(CaseVals[i - 1].second->getLHS()->getBeginLoc(),
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000993 diag::note_duplicate_case_prev);
Mike Stump87c57ac2009-05-16 07:39:55 +0000994 // FIXME: We really want to remove the bogus case stmt from the
995 // substmt, but we have no way to do this right now.
Douglas Gregor2a2d00f2009-05-15 23:57:33 +0000996 CaseListIsErroneous = true;
997 }
998 }
999 }
Mike Stump11289f42009-09-09 15:08:12 +00001000
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001001 // Detect duplicate case ranges, which usually don't exist at all in
1002 // the first place.
1003 if (!CaseRanges.empty()) {
1004 // Sort all the case ranges by their low value so we can easily detect
1005 // overlaps between ranges.
1006 std::stable_sort(CaseRanges.begin(), CaseRanges.end());
Mike Stump11289f42009-09-09 15:08:12 +00001007
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001008 // Scan the ranges, computing the high values and removing empty ranges.
1009 std::vector<llvm::APSInt> HiVals;
1010 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
John McCalld3dfbd62010-05-18 03:19:21 +00001011 llvm::APSInt &LoVal = CaseRanges[i].first;
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001012 CaseStmt *CR = CaseRanges[i].second;
1013 Expr *Hi = CR->getRHS();
Richard Smithf8379a02012-01-18 23:55:52 +00001014
Richard Smithef6c43d2018-07-26 18:41:30 +00001015 const Expr *HiBeforePromotion = Hi;
1016 GetTypeBeforeIntegralPromotion(HiBeforePromotion);
1017 llvm::APSInt HiVal = HiBeforePromotion->EvaluateKnownConstInt(Context);
Mike Stump11289f42009-09-09 15:08:12 +00001018
Richard Smith077d0832014-08-04 00:40:48 +00001019 // Check the unconverted value is within the range of possible values of
1020 // the switch expression.
Stephen Kellyf2ceec42018-08-09 21:08:08 +00001021 checkCaseValue(*this, Hi->getBeginLoc(), HiVal,
Richard Smith077d0832014-08-04 00:40:48 +00001022 CondWidthBeforePromotion, CondIsSignedBeforePromotion);
1023
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001024 // Convert the value to the same width/sign as the condition.
Richard Smith077d0832014-08-04 00:40:48 +00001025 AdjustAPSInt(HiVal, CondWidth, CondIsSigned);
Mike Stump11289f42009-09-09 15:08:12 +00001026
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001027 // If the low value is bigger than the high value, the case is empty.
John McCalld3dfbd62010-05-18 03:19:21 +00001028 if (LoVal > HiVal) {
Stephen Kellyf2ceec42018-08-09 21:08:08 +00001029 Diag(CR->getLHS()->getBeginLoc(), diag::warn_case_empty_range)
Stephen Kelly1c301dc2018-08-09 21:09:38 +00001030 << SourceRange(CR->getLHS()->getBeginLoc(), Hi->getEndLoc());
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001031 CaseRanges.erase(CaseRanges.begin()+i);
Richard Trieucc3949d2016-02-18 22:34:54 +00001032 --i;
1033 --e;
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001034 continue;
1035 }
John McCalld3dfbd62010-05-18 03:19:21 +00001036
1037 if (ShouldCheckConstantCond &&
1038 LoVal <= ConstantCondValue &&
1039 ConstantCondValue <= HiVal)
1040 ShouldCheckConstantCond = false;
1041
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001042 HiVals.push_back(HiVal);
1043 }
Mike Stump11289f42009-09-09 15:08:12 +00001044
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001045 // Rescan the ranges, looking for overlap with singleton values and other
1046 // ranges. Since the range list is sorted, we only need to compare case
1047 // ranges with their neighbors.
1048 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
1049 llvm::APSInt &CRLo = CaseRanges[i].first;
1050 llvm::APSInt &CRHi = HiVals[i];
1051 CaseStmt *CR = CaseRanges[i].second;
Mike Stump11289f42009-09-09 15:08:12 +00001052
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001053 // Check to see whether the case range overlaps with any
1054 // singleton cases.
Craig Topperc3ec1492014-05-26 06:22:03 +00001055 CaseStmt *OverlapStmt = nullptr;
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001056 llvm::APSInt OverlapVal(32);
Mike Stump11289f42009-09-09 15:08:12 +00001057
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001058 // Find the smallest value >= the lower bound. If I is in the
1059 // case range, then we have overlap.
1060 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(),
1061 CaseVals.end(), CRLo,
1062 CaseCompareFunctor());
1063 if (I != CaseVals.end() && I->first < CRHi) {
1064 OverlapVal = I->first; // Found overlap with scalar.
1065 OverlapStmt = I->second;
1066 }
Mike Stump11289f42009-09-09 15:08:12 +00001067
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001068 // Find the smallest value bigger than the upper bound.
1069 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor());
1070 if (I != CaseVals.begin() && (I-1)->first >= CRLo) {
1071 OverlapVal = (I-1)->first; // Found overlap with scalar.
1072 OverlapStmt = (I-1)->second;
1073 }
Mike Stump11289f42009-09-09 15:08:12 +00001074
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001075 // Check to see if this case stmt overlaps with the subsequent
1076 // case range.
1077 if (i && CRLo <= HiVals[i-1]) {
1078 OverlapVal = HiVals[i-1]; // Found overlap with range.
1079 OverlapStmt = CaseRanges[i-1].second;
1080 }
Mike Stump11289f42009-09-09 15:08:12 +00001081
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001082 if (OverlapStmt) {
1083 // If we have a duplicate, report it.
Stephen Kellyf2ceec42018-08-09 21:08:08 +00001084 Diag(CR->getLHS()->getBeginLoc(), diag::err_duplicate_case)
1085 << OverlapVal.toString(10);
1086 Diag(OverlapStmt->getLHS()->getBeginLoc(),
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001087 diag::note_duplicate_case_prev);
Mike Stump87c57ac2009-05-16 07:39:55 +00001088 // FIXME: We really want to remove the bogus case stmt from the
1089 // substmt, but we have no way to do this right now.
Douglas Gregor2a2d00f2009-05-15 23:57:33 +00001090 CaseListIsErroneous = true;
1091 }
Chris Lattnerfcb920d2007-08-23 14:29:07 +00001092 }
Chris Lattner10cb5e52007-08-23 06:23:56 +00001093 }
Douglas Gregorbd6839732010-02-08 22:24:16 +00001094
John McCalld3dfbd62010-05-18 03:19:21 +00001095 // Complain if we have a constant condition and we didn't find a match.
Richard Smithef6c43d2018-07-26 18:41:30 +00001096 if (!CaseListIsErroneous && !CaseListIsIncomplete &&
1097 ShouldCheckConstantCond) {
John McCalld3dfbd62010-05-18 03:19:21 +00001098 // TODO: it would be nice if we printed enums as enums, chars as
1099 // chars, etc.
1100 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition)
1101 << ConstantCondValue.toString(10)
1102 << CondExpr->getSourceRange();
1103 }
1104
1105 // Check to see if switch is over an Enum and handles all of its
Ted Kremenekc42f3452010-09-09 00:05:53 +00001106 // values. We only issue a warning if there is not 'default:', but
1107 // we still do the analysis to preserve this information in the AST
1108 // (which can be used by flow-based analyes).
John McCalld3dfbd62010-05-18 03:19:21 +00001109 //
Chris Lattner51679082010-09-16 17:09:42 +00001110 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>();
Ted Kremenekc42f3452010-09-09 00:05:53 +00001111
Douglas Gregorbd6839732010-02-08 22:24:16 +00001112 // If switch has default case, then ignore it.
Richard Smithef6c43d2018-07-26 18:41:30 +00001113 if (!CaseListIsErroneous && !CaseListIsIncomplete && !HasConstantCond &&
1114 ET && ET->getDecl()->isCompleteDefinition()) {
Douglas Gregorbd6839732010-02-08 22:24:16 +00001115 const EnumDecl *ED = ET->getDecl();
Douglas Gregorbd6839732010-02-08 22:24:16 +00001116 EnumValsTy EnumVals;
1117
John McCalld3dfbd62010-05-18 03:19:21 +00001118 // Gather all enum values, set their type and sort them,
1119 // allowing easier comparison with CaseVals.
Aaron Ballman23a6dcb2014-03-08 18:45:14 +00001120 for (auto *EDI : ED->enumerators()) {
Gabor Greif16e02862010-10-01 22:05:14 +00001121 llvm::APSInt Val = EDI->getInitVal();
1122 AdjustAPSInt(Val, CondWidth, CondIsSigned);
Aaron Ballman23a6dcb2014-03-08 18:45:14 +00001123 EnumVals.push_back(std::make_pair(Val, EDI));
Douglas Gregorbd6839732010-02-08 22:24:16 +00001124 }
1125 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
Alexis Hunt724f14e2014-11-28 00:53:20 +00001126 auto EI = EnumVals.begin(), EIEnd =
John McCalld3dfbd62010-05-18 03:19:21 +00001127 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
Ted Kremenekc42f3452010-09-09 00:05:53 +00001128
1129 // See which case values aren't in enum.
David Blaikiee476f972012-01-22 02:31:55 +00001130 for (CaseValsTy::const_iterator CI = CaseVals.begin();
Alexis Hunt724f14e2014-11-28 00:53:20 +00001131 CI != CaseVals.end(); CI++) {
1132 Expr *CaseExpr = CI->second->getLHS();
1133 if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
1134 CI->first))
1135 Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
1136 << CondTypeBeforePromotion;
David Blaikiee476f972012-01-22 02:31:55 +00001137 }
Alexis Hunt724f14e2014-11-28 00:53:20 +00001138
David Blaikiee476f972012-01-22 02:31:55 +00001139 // See which of case ranges aren't in enum
1140 EI = EnumVals.begin();
1141 for (CaseRangesTy::const_iterator RI = CaseRanges.begin();
Alexis Hunt724f14e2014-11-28 00:53:20 +00001142 RI != CaseRanges.end(); RI++) {
1143 Expr *CaseExpr = RI->second->getLHS();
1144 if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
1145 RI->first))
1146 Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
1147 << CondTypeBeforePromotion;
David Blaikiee476f972012-01-22 02:31:55 +00001148
Chad Rosier02a84392012-08-10 17:56:09 +00001149 llvm::APSInt Hi =
David Blaikiee476f972012-01-22 02:31:55 +00001150 RI->second->getRHS()->EvaluateKnownConstInt(Context);
1151 AdjustAPSInt(Hi, CondWidth, CondIsSigned);
Alexis Hunt724f14e2014-11-28 00:53:20 +00001152
1153 CaseExpr = RI->second->getRHS();
1154 if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd,
1155 Hi))
1156 Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum)
1157 << CondTypeBeforePromotion;
Douglas Gregorbd6839732010-02-08 22:24:16 +00001158 }
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00001159
Ted Kremenekc42f3452010-09-09 00:05:53 +00001160 // Check which enum vals aren't in switch
Alexis Hunt724f14e2014-11-28 00:53:20 +00001161 auto CI = CaseVals.begin();
1162 auto RI = CaseRanges.begin();
Ted Kremenekc42f3452010-09-09 00:05:53 +00001163 bool hasCasesNotInSwitch = false;
1164
Chris Lattner0e62c1c2011-07-23 10:55:15 +00001165 SmallVector<DeclarationName,8> UnhandledNames;
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00001166
Erik Pilkington3e4e3b12018-09-05 19:13:27 +00001167 for (EI = EnumVals.begin(); EI != EIEnd; EI++) {
1168 // Don't warn about omitted unavailable EnumConstantDecls.
1169 switch (EI->second->getAvailability()) {
1170 case AR_Deprecated:
1171 // Omitting a deprecated constant is ok; it should never materialize.
1172 case AR_Unavailable:
1173 continue;
1174
1175 case AR_NotYetIntroduced:
1176 // Partially available enum constants should be present. Note that we
1177 // suppress -Wunguarded-availability diagnostics for such uses.
1178 case AR_Available:
1179 break;
1180 }
1181
Chris Lattner51679082010-09-16 17:09:42 +00001182 // Drop unneeded case values
Douglas Gregorbd6839732010-02-08 22:24:16 +00001183 while (CI != CaseVals.end() && CI->first < EI->first)
1184 CI++;
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00001185
Douglas Gregorbd6839732010-02-08 22:24:16 +00001186 if (CI != CaseVals.end() && CI->first == EI->first)
1187 continue;
1188
Ted Kremenekc42f3452010-09-09 00:05:53 +00001189 // Drop unneeded case ranges
Douglas Gregorbd6839732010-02-08 22:24:16 +00001190 for (; RI != CaseRanges.end(); RI++) {
Richard Smithcaf33902011-10-10 18:28:20 +00001191 llvm::APSInt Hi =
1192 RI->second->getRHS()->EvaluateKnownConstInt(Context);
Gabor Greif16e02862010-10-01 22:05:14 +00001193 AdjustAPSInt(Hi, CondWidth, CondIsSigned);
Douglas Gregorbd6839732010-02-08 22:24:16 +00001194 if (EI->first <= Hi)
1195 break;
1196 }
1197
Ted Kremenekc42f3452010-09-09 00:05:53 +00001198 if (RI == CaseRanges.end() || EI->first < RI->first) {
Ted Kremenek02627a22010-09-09 06:53:59 +00001199 hasCasesNotInSwitch = true;
David Blaikie645ae0c2012-01-21 18:12:07 +00001200 UnhandledNames.push_back(EI->second->getDeclName());
Ted Kremenek02627a22010-09-09 06:53:59 +00001201 }
Douglas Gregorbd6839732010-02-08 22:24:16 +00001202 }
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00001203
Akira Hatanaka3c268af2017-03-21 02:23:00 +00001204 if (TheDefaultStmt && UnhandledNames.empty() && ED->isClosedNonFlag())
David Blaikie60ac6382012-01-23 04:46:12 +00001205 Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default);
David Blaikie645ae0c2012-01-21 18:12:07 +00001206
Chris Lattner51679082010-09-16 17:09:42 +00001207 // Produce a nice diagnostic if multiple values aren't handled.
Benjamin Kramer3a8650a2015-03-27 17:23:14 +00001208 if (!UnhandledNames.empty()) {
1209 DiagnosticBuilder DB = Diag(CondExpr->getExprLoc(),
1210 TheDefaultStmt ? diag::warn_def_missing_case
1211 : diag::warn_missing_case)
1212 << (int)UnhandledNames.size();
1213
1214 for (size_t I = 0, E = std::min(UnhandledNames.size(), (size_t)3);
1215 I != E; ++I)
1216 DB << UnhandledNames[I];
Chris Lattner51679082010-09-16 17:09:42 +00001217 }
Ted Kremenekc42f3452010-09-09 00:05:53 +00001218
1219 if (!hasCasesNotInSwitch)
Ted Kremenek02627a22010-09-09 06:53:59 +00001220 SS->setAllEnumCasesCovered();
Douglas Gregorbd6839732010-02-08 22:24:16 +00001221 }
Chris Lattner10cb5e52007-08-23 06:23:56 +00001222 }
Chris Lattner10cb5e52007-08-23 06:23:56 +00001223
Serge Pavlov921c2ba2014-05-21 14:48:43 +00001224 if (BodyStmt)
Stephen Kelly1c301dc2018-08-09 21:09:38 +00001225 DiagnoseEmptyStmtBody(CondExpr->getEndLoc(), BodyStmt,
Serge Pavlov921c2ba2014-05-21 14:48:43 +00001226 diag::warn_empty_switch_body);
Dmitri Gribenko800ddf32012-02-14 22:14:32 +00001227
Mike Stump87c57ac2009-05-16 07:39:55 +00001228 // FIXME: If the case list was broken is some way, we don't have a good system
1229 // to patch it up. Instead, just return the whole substmt as broken.
Chris Lattner10cb5e52007-08-23 06:23:56 +00001230 if (CaseListIsErroneous)
Sebastian Redl6a8002e2009-01-11 00:38:46 +00001231 return StmtError();
1232
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00001233 return SS;
Chris Lattneraf8d5812006-11-10 05:07:45 +00001234}
1235
Fariborz Jahanian268fec12012-07-17 18:00:08 +00001236void
1237Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType,
1238 Expr *SrcExpr) {
Alp Tokerd4a3f0e2014-06-15 23:30:39 +00001239 if (Diags.isIgnored(diag::warn_not_in_enum_assignment, SrcExpr->getExprLoc()))
Fariborz Jahanian268fec12012-07-17 18:00:08 +00001240 return;
Chad Rosier02a84392012-08-10 17:56:09 +00001241
Fariborz Jahanian268fec12012-07-17 18:00:08 +00001242 if (const EnumType *ET = DstType->getAs<EnumType>())
Dmitri Gribenkoe6ac50a2013-12-05 23:06:53 +00001243 if (!Context.hasSameUnqualifiedType(SrcType, DstType) &&
Fariborz Jahanian268fec12012-07-17 18:00:08 +00001244 SrcType->isIntegerType()) {
1245 if (!SrcExpr->isTypeDependent() && !SrcExpr->isValueDependent() &&
1246 SrcExpr->isIntegerConstantExpr(Context)) {
1247 // Get the bitwidth of the enum value before promotions.
Joey Gouly1ba27332013-06-06 13:48:00 +00001248 unsigned DstWidth = Context.getIntWidth(DstType);
Fariborz Jahanian268fec12012-07-17 18:00:08 +00001249 bool DstIsSigned = DstType->isSignedIntegerOrEnumerationType();
1250
1251 llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context);
Joey Gouly1ba27332013-06-06 13:48:00 +00001252 AdjustAPSInt(RhsVal, DstWidth, DstIsSigned);
Fariborz Jahanian268fec12012-07-17 18:00:08 +00001253 const EnumDecl *ED = ET->getDecl();
Chad Rosier02a84392012-08-10 17:56:09 +00001254
Akira Hatanaka3c268af2017-03-21 02:23:00 +00001255 if (!ED->isClosed())
1256 return;
1257
Alexis Hunt724f14e2014-11-28 00:53:20 +00001258 if (ED->hasAttr<FlagEnumAttr>()) {
1259 if (!IsValueInFlagEnum(ED, RhsVal, true))
1260 Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment)
Dmitri Gribenkoe6ac50a2013-12-05 23:06:53 +00001261 << DstType.getUnqualifiedType();
Alexis Hunt724f14e2014-11-28 00:53:20 +00001262 } else {
1263 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl *>, 64>
1264 EnumValsTy;
1265 EnumValsTy EnumVals;
1266
1267 // Gather all enum values, set their type and sort them,
1268 // allowing easier comparison with rhs constant.
1269 for (auto *EDI : ED->enumerators()) {
1270 llvm::APSInt Val = EDI->getInitVal();
1271 AdjustAPSInt(Val, DstWidth, DstIsSigned);
1272 EnumVals.push_back(std::make_pair(Val, EDI));
1273 }
1274 if (EnumVals.empty())
1275 return;
1276 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
1277 EnumValsTy::iterator EIend =
1278 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
1279
1280 // See which values aren't in the enum.
1281 EnumValsTy::const_iterator EI = EnumVals.begin();
1282 while (EI != EIend && EI->first < RhsVal)
1283 EI++;
1284 if (EI == EIend || EI->first != RhsVal) {
1285 Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment)
1286 << DstType.getUnqualifiedType();
1287 }
Fariborz Jahanian268fec12012-07-17 18:00:08 +00001288 }
1289 }
1290 }
1291}
1292
Richard Smith03a4aa32016-06-23 19:02:52 +00001293StmtResult Sema::ActOnWhileStmt(SourceLocation WhileLoc, ConditionResult Cond,
1294 Stmt *Body) {
1295 if (Cond.isInvalid())
Douglas Gregor7bab5ff2009-11-25 00:27:52 +00001296 return StmtError();
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00001297
Richard Smith03a4aa32016-06-23 19:02:52 +00001298 auto CondVal = Cond.get();
1299 CheckBreakContinueBinding(CondVal.second);
1300
1301 if (CondVal.second &&
1302 !Diags.isIgnored(diag::warn_comma_operator, CondVal.second->getExprLoc()))
1303 CommaVisitor(*this).Visit(CondVal.second);
Richard Trieufaca2d82016-02-18 23:58:40 +00001304
John McCallb268a282010-08-23 23:25:46 +00001305 DiagnoseUnusedExprResult(Body);
Mike Stump11289f42009-09-09 15:08:12 +00001306
Dmitri Gribenko800ddf32012-02-14 22:14:32 +00001307 if (isa<NullStmt>(Body))
1308 getCurCompoundScope().setHasEmptyLoopBodies();
1309
Bruno Riccibacf7512018-10-30 13:42:41 +00001310 return WhileStmt::Create(Context, CondVal.first, CondVal.second, Body,
1311 WhileLoc);
Chris Lattneraf8d5812006-11-10 05:07:45 +00001312}
1313
John McCalldadc5752010-08-24 06:29:42 +00001314StmtResult
John McCallb268a282010-08-23 23:25:46 +00001315Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
Chris Lattner815b70e2009-06-12 23:04:47 +00001316 SourceLocation WhileLoc, SourceLocation CondLParen,
John McCallb268a282010-08-23 23:25:46 +00001317 Expr *Cond, SourceLocation CondRParen) {
1318 assert(Cond && "ActOnDoStmt(): missing expression");
Sebastian Redlfbfaafc2009-01-16 23:28:06 +00001319
Serge Pavlov09f99242014-01-23 15:05:00 +00001320 CheckBreakContinueBinding(Cond);
Richard Smith03a4aa32016-06-23 19:02:52 +00001321 ExprResult CondResult = CheckBooleanCondition(DoLoc, Cond);
Dmitri Gribenkod4bc5ac2012-11-18 22:28:42 +00001322 if (CondResult.isInvalid())
John McCalld5707ab2009-10-12 21:59:07 +00001323 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00001324 Cond = CondResult.get();
Steve Naroff86272ea2007-05-29 02:14:17 +00001325
Richard Smith945f8d32013-01-14 22:39:08 +00001326 CondResult = ActOnFinishFullExpr(Cond, DoLoc);
John McCallb268a282010-08-23 23:25:46 +00001327 if (CondResult.isInvalid())
Douglas Gregore60e41a2010-05-06 17:25:47 +00001328 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00001329 Cond = CondResult.get();
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00001330
Richard Trieuf3713802018-10-25 01:08:00 +00001331 // Only call the CommaVisitor for C89 due to differences in scope flags.
1332 if (Cond && !getLangOpts().C99 && !getLangOpts().CPlusPlus &&
1333 !Diags.isIgnored(diag::warn_comma_operator, Cond->getExprLoc()))
1334 CommaVisitor(*this).Visit(Cond);
1335
John McCallb268a282010-08-23 23:25:46 +00001336 DiagnoseUnusedExprResult(Body);
Anders Carlsson5c5f1602009-07-30 22:39:03 +00001337
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00001338 return new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen);
Chris Lattneraf8d5812006-11-10 05:07:45 +00001339}
1340
Richard Trieu451a5db2012-04-30 18:01:30 +00001341namespace {
Richard Trieu5fb874a2017-06-02 04:24:46 +00001342 // Use SetVector since the diagnostic cares about the ordering of the Decl's.
1343 using DeclSetVector =
1344 llvm::SetVector<VarDecl *, llvm::SmallVector<VarDecl *, 8>,
1345 llvm::SmallPtrSet<VarDecl *, 8>>;
1346
Richard Trieu451a5db2012-04-30 18:01:30 +00001347 // This visitor will traverse a conditional statement and store all
1348 // the evaluated decls into a vector. Simple is set to true if none
1349 // of the excluded constructs are used.
1350 class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> {
Richard Trieu5fb874a2017-06-02 04:24:46 +00001351 DeclSetVector &Decls;
Craig Topperfa159c12013-07-14 16:47:36 +00001352 SmallVectorImpl<SourceRange> &Ranges;
Richard Trieu451a5db2012-04-30 18:01:30 +00001353 bool Simple;
Richard Trieu9d228802013-05-31 22:46:45 +00001354 public:
1355 typedef EvaluatedExprVisitor<DeclExtractor> Inherited;
Richard Trieu451a5db2012-04-30 18:01:30 +00001356
Richard Trieu5fb874a2017-06-02 04:24:46 +00001357 DeclExtractor(Sema &S, DeclSetVector &Decls,
Craig Topperfa159c12013-07-14 16:47:36 +00001358 SmallVectorImpl<SourceRange> &Ranges) :
Richard Trieu9d228802013-05-31 22:46:45 +00001359 Inherited(S.Context),
1360 Decls(Decls),
1361 Ranges(Ranges),
1362 Simple(true) {}
Richard Trieu451a5db2012-04-30 18:01:30 +00001363
Richard Trieu9d228802013-05-31 22:46:45 +00001364 bool isSimple() { return Simple; }
Richard Trieu451a5db2012-04-30 18:01:30 +00001365
Richard Trieu9d228802013-05-31 22:46:45 +00001366 // Replaces the method in EvaluatedExprVisitor.
1367 void VisitMemberExpr(MemberExpr* E) {
Richard Trieu451a5db2012-04-30 18:01:30 +00001368 Simple = false;
Richard Trieu9d228802013-05-31 22:46:45 +00001369 }
1370
1371 // Any Stmt not whitelisted will cause the condition to be marked complex.
1372 void VisitStmt(Stmt *S) {
1373 Simple = false;
1374 }
1375
1376 void VisitBinaryOperator(BinaryOperator *E) {
1377 Visit(E->getLHS());
1378 Visit(E->getRHS());
1379 }
1380
1381 void VisitCastExpr(CastExpr *E) {
Richard Trieu451a5db2012-04-30 18:01:30 +00001382 Visit(E->getSubExpr());
Richard Trieu9d228802013-05-31 22:46:45 +00001383 }
Richard Trieu451a5db2012-04-30 18:01:30 +00001384
Richard Trieu9d228802013-05-31 22:46:45 +00001385 void VisitUnaryOperator(UnaryOperator *E) {
1386 // Skip checking conditionals with derefernces.
1387 if (E->getOpcode() == UO_Deref)
1388 Simple = false;
1389 else
1390 Visit(E->getSubExpr());
1391 }
Richard Trieu451a5db2012-04-30 18:01:30 +00001392
Richard Trieu9d228802013-05-31 22:46:45 +00001393 void VisitConditionalOperator(ConditionalOperator *E) {
1394 Visit(E->getCond());
1395 Visit(E->getTrueExpr());
1396 Visit(E->getFalseExpr());
1397 }
Richard Trieu451a5db2012-04-30 18:01:30 +00001398
Richard Trieu9d228802013-05-31 22:46:45 +00001399 void VisitParenExpr(ParenExpr *E) {
1400 Visit(E->getSubExpr());
1401 }
Richard Trieu451a5db2012-04-30 18:01:30 +00001402
Richard Trieu9d228802013-05-31 22:46:45 +00001403 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) {
1404 Visit(E->getOpaqueValue()->getSourceExpr());
1405 Visit(E->getFalseExpr());
1406 }
Richard Trieu451a5db2012-04-30 18:01:30 +00001407
Richard Trieu9d228802013-05-31 22:46:45 +00001408 void VisitIntegerLiteral(IntegerLiteral *E) { }
1409 void VisitFloatingLiteral(FloatingLiteral *E) { }
1410 void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { }
1411 void VisitCharacterLiteral(CharacterLiteral *E) { }
1412 void VisitGNUNullExpr(GNUNullExpr *E) { }
1413 void VisitImaginaryLiteral(ImaginaryLiteral *E) { }
Richard Trieu451a5db2012-04-30 18:01:30 +00001414
Richard Trieu9d228802013-05-31 22:46:45 +00001415 void VisitDeclRefExpr(DeclRefExpr *E) {
1416 VarDecl *VD = dyn_cast<VarDecl>(E->getDecl());
Richard Trieu6b13e892018-10-20 02:15:58 +00001417 if (!VD) {
1418 // Don't allow unhandled Decl types.
1419 Simple = false;
1420 return;
1421 }
Richard Trieu451a5db2012-04-30 18:01:30 +00001422
Richard Trieu9d228802013-05-31 22:46:45 +00001423 Ranges.push_back(E->getSourceRange());
1424
1425 Decls.insert(VD);
1426 }
Richard Trieu451a5db2012-04-30 18:01:30 +00001427
1428 }; // end class DeclExtractor
1429
Sanjay Patel69e7f6e2015-08-28 14:42:54 +00001430 // DeclMatcher checks to see if the decls are used in a non-evaluated
Chad Rosier02a84392012-08-10 17:56:09 +00001431 // context.
Richard Trieu451a5db2012-04-30 18:01:30 +00001432 class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> {
Richard Trieu5fb874a2017-06-02 04:24:46 +00001433 DeclSetVector &Decls;
Richard Trieu451a5db2012-04-30 18:01:30 +00001434 bool FoundDecl;
Richard Trieu451a5db2012-04-30 18:01:30 +00001435
Richard Trieu9d228802013-05-31 22:46:45 +00001436 public:
1437 typedef EvaluatedExprVisitor<DeclMatcher> Inherited;
Richard Trieu451a5db2012-04-30 18:01:30 +00001438
Richard Trieu5fb874a2017-06-02 04:24:46 +00001439 DeclMatcher(Sema &S, DeclSetVector &Decls, Stmt *Statement) :
Richard Trieu9d228802013-05-31 22:46:45 +00001440 Inherited(S.Context), Decls(Decls), FoundDecl(false) {
1441 if (!Statement) return;
Richard Trieu451a5db2012-04-30 18:01:30 +00001442
Richard Trieu9d228802013-05-31 22:46:45 +00001443 Visit(Statement);
Richard Trieu451a5db2012-04-30 18:01:30 +00001444 }
1445
Richard Trieu9d228802013-05-31 22:46:45 +00001446 void VisitReturnStmt(ReturnStmt *S) {
1447 FoundDecl = true;
Richard Trieu451a5db2012-04-30 18:01:30 +00001448 }
1449
Richard Trieu9d228802013-05-31 22:46:45 +00001450 void VisitBreakStmt(BreakStmt *S) {
1451 FoundDecl = true;
Richard Trieu451a5db2012-04-30 18:01:30 +00001452 }
1453
Richard Trieu9d228802013-05-31 22:46:45 +00001454 void VisitGotoStmt(GotoStmt *S) {
1455 FoundDecl = true;
1456 }
Richard Trieu451a5db2012-04-30 18:01:30 +00001457
Richard Trieu9d228802013-05-31 22:46:45 +00001458 void VisitCastExpr(CastExpr *E) {
1459 if (E->getCastKind() == CK_LValueToRValue)
1460 CheckLValueToRValueCast(E->getSubExpr());
1461 else
1462 Visit(E->getSubExpr());
1463 }
Richard Trieu451a5db2012-04-30 18:01:30 +00001464
Richard Trieu9d228802013-05-31 22:46:45 +00001465 void CheckLValueToRValueCast(Expr *E) {
1466 E = E->IgnoreParenImpCasts();
1467
1468 if (isa<DeclRefExpr>(E)) {
1469 return;
1470 }
1471
1472 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
1473 Visit(CO->getCond());
1474 CheckLValueToRValueCast(CO->getTrueExpr());
1475 CheckLValueToRValueCast(CO->getFalseExpr());
1476 return;
1477 }
1478
1479 if (BinaryConditionalOperator *BCO =
1480 dyn_cast<BinaryConditionalOperator>(E)) {
1481 CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr());
1482 CheckLValueToRValueCast(BCO->getFalseExpr());
1483 return;
1484 }
1485
1486 Visit(E);
1487 }
1488
1489 void VisitDeclRefExpr(DeclRefExpr *E) {
1490 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()))
1491 if (Decls.count(VD))
1492 FoundDecl = true;
1493 }
1494
Steven Wu92910f62016-03-10 02:02:48 +00001495 void VisitPseudoObjectExpr(PseudoObjectExpr *POE) {
1496 // Only need to visit the semantics for POE.
1497 // SyntaticForm doesn't really use the Decal.
1498 for (auto *S : POE->semantics()) {
1499 if (auto *OVE = dyn_cast<OpaqueValueExpr>(S))
1500 // Look past the OVE into the expression it binds.
1501 Visit(OVE->getSourceExpr());
1502 else
1503 Visit(S);
1504 }
1505 }
1506
Richard Trieu9d228802013-05-31 22:46:45 +00001507 bool FoundDeclInUse() { return FoundDecl; }
Richard Trieu451a5db2012-04-30 18:01:30 +00001508
1509 }; // end class DeclMatcher
1510
1511 void CheckForLoopConditionalStatement(Sema &S, Expr *Second,
1512 Expr *Third, Stmt *Body) {
1513 // Condition is empty
1514 if (!Second) return;
1515
Alp Tokerd4a3f0e2014-06-15 23:30:39 +00001516 if (S.Diags.isIgnored(diag::warn_variables_not_in_loop_body,
Stephen Kellyf2ceec42018-08-09 21:08:08 +00001517 Second->getBeginLoc()))
Richard Trieu451a5db2012-04-30 18:01:30 +00001518 return;
1519
1520 PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body);
Richard Trieu5fb874a2017-06-02 04:24:46 +00001521 DeclSetVector Decls;
Dmitri Gribenkof8579502013-01-12 19:30:44 +00001522 SmallVector<SourceRange, 10> Ranges;
Benjamin Kramerd1d76b22012-06-06 17:32:50 +00001523 DeclExtractor DE(S, Decls, Ranges);
Richard Trieu451a5db2012-04-30 18:01:30 +00001524 DE.Visit(Second);
1525
1526 // Don't analyze complex conditionals.
1527 if (!DE.isSimple()) return;
1528
1529 // No decls found.
1530 if (Decls.size() == 0) return;
1531
Richard Trieu0030f1d2012-05-04 03:01:54 +00001532 // Don't warn on volatile, static, or global variables.
Richard Trieu5fb874a2017-06-02 04:24:46 +00001533 for (auto *VD : Decls)
1534 if (VD->getType().isVolatileQualified() || VD->hasGlobalStorage())
1535 return;
Richard Trieu451a5db2012-04-30 18:01:30 +00001536
1537 if (DeclMatcher(S, Decls, Second).FoundDeclInUse() ||
1538 DeclMatcher(S, Decls, Third).FoundDeclInUse() ||
1539 DeclMatcher(S, Decls, Body).FoundDeclInUse())
1540 return;
1541
1542 // Load decl names into diagnostic.
Richard Trieu5fb874a2017-06-02 04:24:46 +00001543 if (Decls.size() > 4) {
Richard Trieu451a5db2012-04-30 18:01:30 +00001544 PDiag << 0;
Richard Trieu5fb874a2017-06-02 04:24:46 +00001545 } else {
1546 PDiag << (unsigned)Decls.size();
1547 for (auto *VD : Decls)
1548 PDiag << VD->getDeclName();
Richard Trieu451a5db2012-04-30 18:01:30 +00001549 }
1550
Richard Trieu5fb874a2017-06-02 04:24:46 +00001551 for (auto Range : Ranges)
1552 PDiag << Range;
Richard Trieu451a5db2012-04-30 18:01:30 +00001553
1554 S.Diag(Ranges.begin()->getBegin(), PDiag);
1555 }
1556
Richard Trieu4e7c9622013-08-06 21:31:54 +00001557 // If Statement is an incemement or decrement, return true and sets the
1558 // variables Increment and DRE.
1559 bool ProcessIterationStmt(Sema &S, Stmt* Statement, bool &Increment,
1560 DeclRefExpr *&DRE) {
Tim Shen4a05bb82016-06-21 20:29:17 +00001561 if (auto Cleanups = dyn_cast<ExprWithCleanups>(Statement))
1562 if (!Cleanups->cleanupsHaveSideEffects())
1563 Statement = Cleanups->getSubExpr();
1564
Richard Trieu4e7c9622013-08-06 21:31:54 +00001565 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(Statement)) {
1566 switch (UO->getOpcode()) {
1567 default: return false;
1568 case UO_PostInc:
1569 case UO_PreInc:
1570 Increment = true;
1571 break;
1572 case UO_PostDec:
1573 case UO_PreDec:
1574 Increment = false;
1575 break;
1576 }
1577 DRE = dyn_cast<DeclRefExpr>(UO->getSubExpr());
1578 return DRE;
1579 }
1580
1581 if (CXXOperatorCallExpr *Call = dyn_cast<CXXOperatorCallExpr>(Statement)) {
1582 FunctionDecl *FD = Call->getDirectCallee();
1583 if (!FD || !FD->isOverloadedOperator()) return false;
1584 switch (FD->getOverloadedOperator()) {
1585 default: return false;
1586 case OO_PlusPlus:
1587 Increment = true;
1588 break;
1589 case OO_MinusMinus:
1590 Increment = false;
1591 break;
1592 }
1593 DRE = dyn_cast<DeclRefExpr>(Call->getArg(0));
1594 return DRE;
1595 }
1596
1597 return false;
1598 }
1599
Serge Pavlov09f99242014-01-23 15:05:00 +00001600 // A visitor to determine if a continue or break statement is a
1601 // subexpression.
Eli Friedmane91b2e62017-07-04 00:52:24 +00001602 class BreakContinueFinder : public ConstEvaluatedExprVisitor<BreakContinueFinder> {
Serge Pavlov09f99242014-01-23 15:05:00 +00001603 SourceLocation BreakLoc;
1604 SourceLocation ContinueLoc;
Eli Friedmane91b2e62017-07-04 00:52:24 +00001605 bool InSwitch = false;
1606
Richard Trieu4e7c9622013-08-06 21:31:54 +00001607 public:
Eli Friedmane91b2e62017-07-04 00:52:24 +00001608 BreakContinueFinder(Sema &S, const Stmt* Body) :
Serge Pavlov09f99242014-01-23 15:05:00 +00001609 Inherited(S.Context) {
Richard Trieu4e7c9622013-08-06 21:31:54 +00001610 Visit(Body);
1611 }
1612
Eli Friedmane91b2e62017-07-04 00:52:24 +00001613 typedef ConstEvaluatedExprVisitor<BreakContinueFinder> Inherited;
Richard Trieu4e7c9622013-08-06 21:31:54 +00001614
Eli Friedmane91b2e62017-07-04 00:52:24 +00001615 void VisitContinueStmt(const ContinueStmt* E) {
Serge Pavlov09f99242014-01-23 15:05:00 +00001616 ContinueLoc = E->getContinueLoc();
Richard Trieu4e7c9622013-08-06 21:31:54 +00001617 }
1618
Eli Friedmane91b2e62017-07-04 00:52:24 +00001619 void VisitBreakStmt(const BreakStmt* E) {
1620 if (!InSwitch)
1621 BreakLoc = E->getBreakLoc();
1622 }
1623
1624 void VisitSwitchStmt(const SwitchStmt* S) {
1625 if (const Stmt *Init = S->getInit())
1626 Visit(Init);
1627 if (const Stmt *CondVar = S->getConditionVariableDeclStmt())
1628 Visit(CondVar);
1629 if (const Stmt *Cond = S->getCond())
1630 Visit(Cond);
1631
1632 // Don't return break statements from the body of a switch.
1633 InSwitch = true;
1634 if (const Stmt *Body = S->getBody())
1635 Visit(Body);
1636 InSwitch = false;
1637 }
1638
1639 void VisitForStmt(const ForStmt *S) {
1640 // Only visit the init statement of a for loop; the body
1641 // has a different break/continue scope.
1642 if (const Stmt *Init = S->getInit())
1643 Visit(Init);
1644 }
1645
1646 void VisitWhileStmt(const WhileStmt *) {
1647 // Do nothing; the children of a while loop have a different
1648 // break/continue scope.
1649 }
1650
1651 void VisitDoStmt(const DoStmt *) {
1652 // Do nothing; the children of a while loop have a different
1653 // break/continue scope.
1654 }
1655
1656 void VisitCXXForRangeStmt(const CXXForRangeStmt *S) {
1657 // Only visit the initialization of a for loop; the body
1658 // has a different break/continue scope.
Richard Smith8baa5002018-09-28 18:44:09 +00001659 if (const Stmt *Init = S->getInit())
1660 Visit(Init);
Eli Friedmane91b2e62017-07-04 00:52:24 +00001661 if (const Stmt *Range = S->getRangeStmt())
1662 Visit(Range);
1663 if (const Stmt *Begin = S->getBeginStmt())
1664 Visit(Begin);
1665 if (const Stmt *End = S->getEndStmt())
1666 Visit(End);
1667 }
1668
1669 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S) {
1670 // Only visit the initialization of a for loop; the body
1671 // has a different break/continue scope.
1672 if (const Stmt *Element = S->getElement())
1673 Visit(Element);
1674 if (const Stmt *Collection = S->getCollection())
1675 Visit(Collection);
Serge Pavlov09f99242014-01-23 15:05:00 +00001676 }
Richard Trieu4e7c9622013-08-06 21:31:54 +00001677
Serge Pavlov09f99242014-01-23 15:05:00 +00001678 bool ContinueFound() { return ContinueLoc.isValid(); }
1679 bool BreakFound() { return BreakLoc.isValid(); }
1680 SourceLocation GetContinueLoc() { return ContinueLoc; }
1681 SourceLocation GetBreakLoc() { return BreakLoc; }
1682
1683 }; // end class BreakContinueFinder
Richard Trieu4e7c9622013-08-06 21:31:54 +00001684
1685 // Emit a warning when a loop increment/decrement appears twice per loop
1686 // iteration. The conditions which trigger this warning are:
1687 // 1) The last statement in the loop body and the third expression in the
1688 // for loop are both increment or both decrement of the same variable
1689 // 2) No continue statements in the loop body.
1690 void CheckForRedundantIteration(Sema &S, Expr *Third, Stmt *Body) {
1691 // Return when there is nothing to check.
1692 if (!Body || !Third) return;
1693
Alp Tokerd4a3f0e2014-06-15 23:30:39 +00001694 if (S.Diags.isIgnored(diag::warn_redundant_loop_iteration,
Stephen Kellyf2ceec42018-08-09 21:08:08 +00001695 Third->getBeginLoc()))
Richard Trieu4e7c9622013-08-06 21:31:54 +00001696 return;
1697
1698 // Get the last statement from the loop body.
1699 CompoundStmt *CS = dyn_cast<CompoundStmt>(Body);
1700 if (!CS || CS->body_empty()) return;
1701 Stmt *LastStmt = CS->body_back();
1702 if (!LastStmt) return;
1703
1704 bool LoopIncrement, LastIncrement;
1705 DeclRefExpr *LoopDRE, *LastDRE;
1706
1707 if (!ProcessIterationStmt(S, Third, LoopIncrement, LoopDRE)) return;
1708 if (!ProcessIterationStmt(S, LastStmt, LastIncrement, LastDRE)) return;
1709
1710 // Check that the two statements are both increments or both decrements
Serge Pavlov09f99242014-01-23 15:05:00 +00001711 // on the same variable.
Richard Trieu4e7c9622013-08-06 21:31:54 +00001712 if (LoopIncrement != LastIncrement ||
1713 LoopDRE->getDecl() != LastDRE->getDecl()) return;
1714
Serge Pavlov09f99242014-01-23 15:05:00 +00001715 if (BreakContinueFinder(S, Body).ContinueFound()) return;
Richard Trieu4e7c9622013-08-06 21:31:54 +00001716
1717 S.Diag(LastDRE->getLocation(), diag::warn_redundant_loop_iteration)
1718 << LastDRE->getDecl() << LastIncrement;
1719 S.Diag(LoopDRE->getLocation(), diag::note_loop_iteration_here)
1720 << LoopIncrement;
1721 }
1722
Richard Trieu451a5db2012-04-30 18:01:30 +00001723} // end namespace
1724
Serge Pavlov09f99242014-01-23 15:05:00 +00001725
1726void Sema::CheckBreakContinueBinding(Expr *E) {
1727 if (!E || getLangOpts().CPlusPlus)
1728 return;
1729 BreakContinueFinder BCFinder(*this, E);
1730 Scope *BreakParent = CurScope->getBreakParent();
1731 if (BCFinder.BreakFound() && BreakParent) {
1732 if (BreakParent->getFlags() & Scope::SwitchScope) {
1733 Diag(BCFinder.GetBreakLoc(), diag::warn_break_binds_to_switch);
1734 } else {
1735 Diag(BCFinder.GetBreakLoc(), diag::warn_loop_ctrl_binds_to_inner)
1736 << "break";
1737 }
1738 } else if (BCFinder.ContinueFound() && CurScope->getContinueParent()) {
1739 Diag(BCFinder.GetContinueLoc(), diag::warn_loop_ctrl_binds_to_inner)
1740 << "continue";
1741 }
1742}
1743
Richard Smith03a4aa32016-06-23 19:02:52 +00001744StmtResult Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
1745 Stmt *First, ConditionResult Second,
1746 FullExprArg third, SourceLocation RParenLoc,
1747 Stmt *Body) {
1748 if (Second.isInvalid())
1749 return StmtError();
1750
David Blaikiebbafb8a2012-03-11 07:00:24 +00001751 if (!getLangOpts().CPlusPlus) {
Argyrios Kyrtzidis7620ee42008-09-10 02:17:11 +00001752 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) {
Chris Lattner651d42d2008-11-20 06:38:18 +00001753 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
1754 // declare identifiers for objects having storage class 'auto' or
1755 // 'register'.
Aaron Ballman535bbcc2014-03-14 17:01:24 +00001756 for (auto *DI : DS->decls()) {
1757 VarDecl *VD = dyn_cast<VarDecl>(DI);
John McCall1c9c3fd2010-10-15 04:57:14 +00001758 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage())
Craig Topperc3ec1492014-05-26 06:22:03 +00001759 VD = nullptr;
1760 if (!VD) {
Aaron Ballman535bbcc2014-03-14 17:01:24 +00001761 Diag(DI->getLocation(), diag::err_non_local_variable_decl_in_for);
1762 DI->setInvalidDecl();
Douglas Gregor2eb1c572013-04-08 20:52:24 +00001763 }
Argyrios Kyrtzidis7620ee42008-09-10 02:17:11 +00001764 }
Chris Lattner39f920f2007-08-28 05:03:08 +00001765 }
Steve Naroff86272ea2007-05-29 02:14:17 +00001766 }
Douglas Gregor7bab5ff2009-11-25 00:27:52 +00001767
Richard Smith03a4aa32016-06-23 19:02:52 +00001768 CheckBreakContinueBinding(Second.get().second);
Serge Pavlov09f99242014-01-23 15:05:00 +00001769 CheckBreakContinueBinding(third.get());
1770
Richard Smith03a4aa32016-06-23 19:02:52 +00001771 if (!Second.get().first)
1772 CheckForLoopConditionalStatement(*this, Second.get().second, third.get(),
1773 Body);
Richard Trieu4e7c9622013-08-06 21:31:54 +00001774 CheckForRedundantIteration(*this, third.get(), Body);
Richard Trieu451a5db2012-04-30 18:01:30 +00001775
Richard Smith03a4aa32016-06-23 19:02:52 +00001776 if (Second.get().second &&
Richard Trieufaca2d82016-02-18 23:58:40 +00001777 !Diags.isIgnored(diag::warn_comma_operator,
Richard Smith03a4aa32016-06-23 19:02:52 +00001778 Second.get().second->getExprLoc()))
1779 CommaVisitor(*this).Visit(Second.get().second);
Richard Trieufaca2d82016-02-18 23:58:40 +00001780
Nikola Smiljanic01a75982014-05-29 10:55:11 +00001781 Expr *Third = third.release().getAs<Expr>();
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00001782
Anders Carlsson1682af52009-08-01 01:39:59 +00001783 DiagnoseUnusedExprResult(First);
1784 DiagnoseUnusedExprResult(Third);
Anders Carlsson5c5f1602009-07-30 22:39:03 +00001785 DiagnoseUnusedExprResult(Body);
1786
Dmitri Gribenko800ddf32012-02-14 22:14:32 +00001787 if (isa<NullStmt>(Body))
1788 getCurCompoundScope().setHasEmptyLoopBodies();
1789
Richard Smith03a4aa32016-06-23 19:02:52 +00001790 return new (Context)
1791 ForStmt(Context, First, Second.get().second, Second.get().first, Third,
1792 Body, ForLoc, LParenLoc, RParenLoc);
Chris Lattneraf8d5812006-11-10 05:07:45 +00001793}
1794
John McCall34376a62010-12-04 03:47:34 +00001795/// In an Objective C collection iteration statement:
1796/// for (x in y)
1797/// x can be an arbitrary l-value expression. Bind it up as a
1798/// full-expression.
1799StmtResult Sema::ActOnForEachLValueExpr(Expr *E) {
John McCallbc153352012-03-30 05:43:39 +00001800 // Reduce placeholder expressions here. Note that this rejects the
1801 // use of pseudo-object l-values in this position.
1802 ExprResult result = CheckPlaceholderExpr(E);
1803 if (result.isInvalid()) return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00001804 E = result.get();
John McCallbc153352012-03-30 05:43:39 +00001805
Richard Smith945f8d32013-01-14 22:39:08 +00001806 ExprResult FullExpr = ActOnFinishFullExpr(E);
1807 if (FullExpr.isInvalid())
1808 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00001809 return StmtResult(static_cast<Stmt*>(FullExpr.get()));
John McCall34376a62010-12-04 03:47:34 +00001810}
1811
John McCall53848232011-07-27 01:07:15 +00001812ExprResult
Fariborz Jahanian450bb6e2012-07-03 22:00:52 +00001813Sema::CheckObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) {
1814 if (!collection)
1815 return ExprError();
Chad Rosier02a84392012-08-10 17:56:09 +00001816
Kaelyn Takata15867822014-11-21 18:48:04 +00001817 ExprResult result = CorrectDelayedTyposInExpr(collection);
1818 if (!result.isUsable())
1819 return ExprError();
1820 collection = result.get();
1821
John McCall53848232011-07-27 01:07:15 +00001822 // Bail out early if we've got a type-dependent expression.
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00001823 if (collection->isTypeDependent()) return collection;
John McCall53848232011-07-27 01:07:15 +00001824
1825 // Perform normal l-value conversion.
Kaelyn Takata15867822014-11-21 18:48:04 +00001826 result = DefaultFunctionArrayLvalueConversion(collection);
John McCall53848232011-07-27 01:07:15 +00001827 if (result.isInvalid())
1828 return ExprError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00001829 collection = result.get();
John McCall53848232011-07-27 01:07:15 +00001830
1831 // The operand needs to have object-pointer type.
1832 // TODO: should we do a contextual conversion?
1833 const ObjCObjectPointerType *pointerType =
1834 collection->getType()->getAs<ObjCObjectPointerType>();
1835 if (!pointerType)
1836 return Diag(forLoc, diag::err_collection_expr_type)
1837 << collection->getType() << collection->getSourceRange();
1838
1839 // Check that the operand provides
1840 // - countByEnumeratingWithState:objects:count:
1841 const ObjCObjectType *objectType = pointerType->getObjectType();
1842 ObjCInterfaceDecl *iface = objectType->getInterface();
1843
1844 // If we have a forward-declared type, we can't do this check.
Douglas Gregor4123a862011-11-14 22:10:01 +00001845 // Under ARC, it is an error not to have a forward-declared class.
Chad Rosier02a84392012-08-10 17:56:09 +00001846 if (iface &&
Richard Smithdb0ac552015-12-18 22:40:25 +00001847 (getLangOpts().ObjCAutoRefCount
1848 ? RequireCompleteType(forLoc, QualType(objectType, 0),
1849 diag::err_arc_collection_forward, collection)
1850 : !isCompleteType(forLoc, QualType(objectType, 0)))) {
John McCall53848232011-07-27 01:07:15 +00001851 // Otherwise, if we have any useful type information, check that
1852 // the type declares the appropriate method.
1853 } else if (iface || !objectType->qual_empty()) {
1854 IdentifierInfo *selectorIdents[] = {
1855 &Context.Idents.get("countByEnumeratingWithState"),
1856 &Context.Idents.get("objects"),
1857 &Context.Idents.get("count")
1858 };
1859 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]);
1860
Craig Topperc3ec1492014-05-26 06:22:03 +00001861 ObjCMethodDecl *method = nullptr;
John McCall53848232011-07-27 01:07:15 +00001862
1863 // If there's an interface, look in both the public and private APIs.
1864 if (iface) {
1865 method = iface->lookupInstanceMethod(selector);
Anna Zaksc77a3b12012-07-27 19:07:44 +00001866 if (!method) method = iface->lookupPrivateMethod(selector);
John McCall53848232011-07-27 01:07:15 +00001867 }
1868
1869 // Also check protocol qualifiers.
1870 if (!method)
1871 method = LookupMethodInQualifiedType(selector, pointerType,
1872 /*instance*/ true);
1873
1874 // If we didn't find it anywhere, give up.
1875 if (!method) {
1876 Diag(forLoc, diag::warn_collection_expr_type)
1877 << collection->getType() << selector << collection->getSourceRange();
1878 }
1879
1880 // TODO: check for an incompatible signature?
1881 }
1882
1883 // Wrap up any cleanups in the expression.
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00001884 return collection;
John McCall53848232011-07-27 01:07:15 +00001885}
1886
John McCalldadc5752010-08-24 06:29:42 +00001887StmtResult
Sebastian Redlfbfaafc2009-01-16 23:28:06 +00001888Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc,
Fariborz Jahanian450bb6e2012-07-03 22:00:52 +00001889 Stmt *First, Expr *collection,
1890 SourceLocation RParenLoc) {
Reid Kleckner87a31802018-03-12 21:43:02 +00001891 setFunctionHasBranchProtectedScope();
Chad Rosier02a84392012-08-10 17:56:09 +00001892
1893 ExprResult CollectionExprResult =
Fariborz Jahanian450bb6e2012-07-03 22:00:52 +00001894 CheckObjCForCollectionOperand(ForLoc, collection);
Chad Rosier02a84392012-08-10 17:56:09 +00001895
Fariborz Jahanian93977672008-01-10 20:33:58 +00001896 if (First) {
1897 QualType FirstType;
1898 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) {
Chris Lattner529efc72009-03-28 06:33:19 +00001899 if (!DS->isSingleDecl())
Sebastian Redlfbfaafc2009-01-16 23:28:06 +00001900 return StmtError(Diag((*DS->decl_begin())->getLocation(),
1901 diag::err_toomany_element_decls));
1902
Douglas Gregor2eb1c572013-04-08 20:52:24 +00001903 VarDecl *D = dyn_cast<VarDecl>(DS->getSingleDecl());
1904 if (!D || D->isInvalidDecl())
1905 return StmtError();
Fangrui Song6907ce22018-07-30 19:24:48 +00001906
John McCall31168b02011-06-15 23:02:42 +00001907 FirstType = D->getType();
Chris Lattner651d42d2008-11-20 06:38:18 +00001908 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
1909 // declare identifiers for objects having storage class 'auto' or
1910 // 'register'.
John McCall31168b02011-06-15 23:02:42 +00001911 if (!D->hasLocalStorage())
1912 return StmtError(Diag(D->getLocation(),
Douglas Gregor2eb1c572013-04-08 20:52:24 +00001913 diag::err_non_local_variable_decl_in_for));
Douglas Gregorc430f452013-04-08 18:25:02 +00001914
1915 // If the type contained 'auto', deduce the 'auto' to 'id'.
1916 if (FirstType->getContainedAutoType()) {
Douglas Gregorc430f452013-04-08 18:25:02 +00001917 OpaqueValueExpr OpaqueId(D->getLocation(), Context.getObjCIdType(),
1918 VK_RValue);
1919 Expr *DeducedInit = &OpaqueId;
Richard Smith061f1e22013-04-30 21:23:01 +00001920 if (DeduceAutoType(D->getTypeSourceInfo(), DeducedInit, FirstType) ==
1921 DAR_Failed)
Douglas Gregorc430f452013-04-08 18:25:02 +00001922 DiagnoseAutoDeductionFailure(D, DeducedInit);
Richard Smith061f1e22013-04-30 21:23:01 +00001923 if (FirstType.isNull()) {
Douglas Gregorc430f452013-04-08 18:25:02 +00001924 D->setInvalidDecl();
1925 return StmtError();
1926 }
1927
Richard Smith061f1e22013-04-30 21:23:01 +00001928 D->setType(FirstType);
Douglas Gregorc430f452013-04-08 18:25:02 +00001929
Richard Smith51ec0cf2017-02-21 01:17:38 +00001930 if (!inTemplateInstantiation()) {
Richard Smith061f1e22013-04-30 21:23:01 +00001931 SourceLocation Loc =
1932 D->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
Douglas Gregorc430f452013-04-08 18:25:02 +00001933 Diag(Loc, diag::warn_auto_var_is_id)
1934 << D->getDeclName();
1935 }
1936 }
1937
Anders Carlsson1ec2ccd2008-08-25 18:16:36 +00001938 } else {
Douglas Gregorf68a5082010-04-22 23:10:45 +00001939 Expr *FirstE = cast<Expr>(First);
John McCall086a4642010-11-24 05:12:34 +00001940 if (!FirstE->isTypeDependent() && !FirstE->isLValue())
Stephen Kellyf2ceec42018-08-09 21:08:08 +00001941 return StmtError(
1942 Diag(First->getBeginLoc(), diag::err_selector_element_not_lvalue)
1943 << First->getSourceRange());
Sebastian Redlfbfaafc2009-01-16 23:28:06 +00001944
Mike Stump11289f42009-09-09 15:08:12 +00001945 FirstType = static_cast<Expr*>(First)->getType();
Fariborz Jahanian8bcf1822013-10-10 21:58:04 +00001946 if (FirstType.isConstQualified())
1947 Diag(ForLoc, diag::err_selector_element_const_type)
1948 << FirstType << First->getSourceRange();
Anders Carlsson1ec2ccd2008-08-25 18:16:36 +00001949 }
Douglas Gregorf68a5082010-04-22 23:10:45 +00001950 if (!FirstType->isDependentType() &&
1951 !FirstType->isObjCObjectPointerType() &&
Fariborz Jahanian2e4a46b2009-08-14 21:53:27 +00001952 !FirstType->isBlockPointerType())
Fariborz Jahanian450bb6e2012-07-03 22:00:52 +00001953 return StmtError(Diag(ForLoc, diag::err_selector_element_type)
1954 << FirstType << First->getSourceRange());
Fariborz Jahanian732b8c22008-01-03 17:55:25 +00001955 }
Chad Rosier02a84392012-08-10 17:56:09 +00001956
Fariborz Jahanian450bb6e2012-07-03 22:00:52 +00001957 if (CollectionExprResult.isInvalid())
1958 return StmtError();
Chad Rosier02a84392012-08-10 17:56:09 +00001959
Nikola Smiljanic01a75982014-05-29 10:55:11 +00001960 CollectionExprResult = ActOnFinishFullExpr(CollectionExprResult.get());
Richard Smith945f8d32013-01-14 22:39:08 +00001961 if (CollectionExprResult.isInvalid())
1962 return StmtError();
1963
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00001964 return new (Context) ObjCForCollectionStmt(First, CollectionExprResult.get(),
1965 nullptr, ForLoc, RParenLoc);
Fariborz Jahanian732b8c22008-01-03 17:55:25 +00001966}
Chris Lattneraf8d5812006-11-10 05:07:45 +00001967
Richard Smith02e85f32011-04-14 22:09:26 +00001968/// Finish building a variable declaration for a for-range statement.
1969/// \return true if an error occurs.
1970static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init,
Richard Smith061f1e22013-04-30 21:23:01 +00001971 SourceLocation Loc, int DiagID) {
Kaelyn Takatafb8cf402015-05-07 00:11:02 +00001972 if (Decl->getType()->isUndeducedType()) {
1973 ExprResult Res = SemaRef.CorrectDelayedTyposInExpr(Init);
1974 if (!Res.isUsable()) {
1975 Decl->setInvalidDecl();
1976 return true;
1977 }
1978 Init = Res.get();
1979 }
1980
Richard Smith02e85f32011-04-14 22:09:26 +00001981 // Deduce the type for the iterator variable now rather than leaving it to
1982 // AddInitializerToDecl, so we can produce a more suitable diagnostic.
Richard Smith061f1e22013-04-30 21:23:01 +00001983 QualType InitType;
Sebastian Redl42acd4a2012-01-17 22:50:08 +00001984 if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) ||
Richard Smith061f1e22013-04-30 21:23:01 +00001985 SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitType) ==
Sebastian Redl09edce02012-01-23 22:09:39 +00001986 Sema::DAR_Failed)
Richard Smith061f1e22013-04-30 21:23:01 +00001987 SemaRef.Diag(Loc, DiagID) << Init->getType();
1988 if (InitType.isNull()) {
Richard Smith02e85f32011-04-14 22:09:26 +00001989 Decl->setInvalidDecl();
1990 return true;
1991 }
Richard Smith061f1e22013-04-30 21:23:01 +00001992 Decl->setType(InitType);
Richard Smith02e85f32011-04-14 22:09:26 +00001993
John McCall31168b02011-06-15 23:02:42 +00001994 // In ARC, infer lifetime.
1995 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if
1996 // we're doing the equivalent of fast iteration.
Chad Rosier02a84392012-08-10 17:56:09 +00001997 if (SemaRef.getLangOpts().ObjCAutoRefCount &&
John McCall31168b02011-06-15 23:02:42 +00001998 SemaRef.inferObjCARCLifetime(Decl))
1999 Decl->setInvalidDecl();
2000
Richard Smith3beb7c62017-01-12 02:27:38 +00002001 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false);
Richard Smith02e85f32011-04-14 22:09:26 +00002002 SemaRef.FinalizeDeclaration(Decl);
Richard Smith0c502d22011-04-18 15:49:25 +00002003 SemaRef.CurContext->addHiddenDecl(Decl);
Richard Smith02e85f32011-04-14 22:09:26 +00002004 return false;
2005}
2006
Sam Panzer0f384432012-08-21 00:52:01 +00002007namespace {
Richard Smith9f690bd2015-10-27 06:02:45 +00002008// An enum to represent whether something is dealing with a call to begin()
2009// or a call to end() in a range-based for loop.
2010enum BeginEndFunction {
2011 BEF_begin,
2012 BEF_end
2013};
Sam Panzer0f384432012-08-21 00:52:01 +00002014
Richard Smith02e85f32011-04-14 22:09:26 +00002015/// Produce a note indicating which begin/end function was implicitly called
Sam Panzer0f384432012-08-21 00:52:01 +00002016/// by a C++11 for-range statement. This is often not obvious from the code,
Richard Smith02e85f32011-04-14 22:09:26 +00002017/// nor from the diagnostics produced when analysing the implicit expressions
2018/// required in a for-range statement.
2019void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E,
Richard Smith9f690bd2015-10-27 06:02:45 +00002020 BeginEndFunction BEF) {
Richard Smith02e85f32011-04-14 22:09:26 +00002021 CallExpr *CE = dyn_cast<CallExpr>(E);
2022 if (!CE)
2023 return;
2024 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl());
2025 if (!D)
2026 return;
2027 SourceLocation Loc = D->getLocation();
2028
2029 std::string Description;
2030 bool IsTemplate = false;
2031 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) {
2032 Description = SemaRef.getTemplateArgumentBindingsText(
2033 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs());
2034 IsTemplate = true;
2035 }
2036
2037 SemaRef.Diag(Loc, diag::note_for_range_begin_end)
2038 << BEF << IsTemplate << Description << E->getType();
2039}
2040
Sam Panzer0f384432012-08-21 00:52:01 +00002041/// Build a variable declaration for a for-range statement.
2042VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc,
Matt Davisb8402ef2018-02-14 21:22:11 +00002043 QualType Type, StringRef Name) {
Sam Panzer0f384432012-08-21 00:52:01 +00002044 DeclContext *DC = SemaRef.CurContext;
2045 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name);
2046 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc);
2047 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type,
Rafael Espindola6ae7e502013-04-03 19:27:57 +00002048 TInfo, SC_None);
Sam Panzer0f384432012-08-21 00:52:01 +00002049 Decl->setImplicit();
2050 return Decl;
Richard Smith02e85f32011-04-14 22:09:26 +00002051}
2052
Alexander Kornienkoab9db512015-06-22 23:07:51 +00002053}
Richard Smith02e85f32011-04-14 22:09:26 +00002054
Fariborz Jahanian00213472012-07-06 19:04:04 +00002055static bool ObjCEnumerationCollection(Expr *Collection) {
2056 return !Collection->isTypeDependent()
Craig Topperc3ec1492014-05-26 06:22:03 +00002057 && Collection->getType()->getAs<ObjCObjectPointerType>() != nullptr;
Fariborz Jahanian00213472012-07-06 19:04:04 +00002058}
2059
Sam Panzer2c4ca0f2012-08-16 21:47:25 +00002060/// ActOnCXXForRangeStmt - Check and build a C++11 for-range statement.
Richard Smith02e85f32011-04-14 22:09:26 +00002061///
Sam Panzer2c4ca0f2012-08-16 21:47:25 +00002062/// C++11 [stmt.ranged]:
Richard Smith02e85f32011-04-14 22:09:26 +00002063/// A range-based for statement is equivalent to
2064///
2065/// {
2066/// auto && __range = range-init;
2067/// for ( auto __begin = begin-expr,
2068/// __end = end-expr;
2069/// __begin != __end;
2070/// ++__begin ) {
2071/// for-range-declaration = *__begin;
2072/// statement
2073/// }
2074/// }
2075///
2076/// The body of the loop is not available yet, since it cannot be analysed until
2077/// we have determined the type of the for-range-declaration.
Richard Smith9f690bd2015-10-27 06:02:45 +00002078StmtResult Sema::ActOnCXXForRangeStmt(Scope *S, SourceLocation ForLoc,
Richard Smith8baa5002018-09-28 18:44:09 +00002079 SourceLocation CoawaitLoc, Stmt *InitStmt,
2080 Stmt *First, SourceLocation ColonLoc,
2081 Expr *Range, SourceLocation RParenLoc,
Richard Smith9f690bd2015-10-27 06:02:45 +00002082 BuildForRangeKind Kind) {
Richard Smith3249fed2013-08-21 01:40:36 +00002083 if (!First)
Richard Smith02e85f32011-04-14 22:09:26 +00002084 return StmtError();
Chad Rosier02a84392012-08-10 17:56:09 +00002085
Richard Smith8baa5002018-09-28 18:44:09 +00002086 if (Range && ObjCEnumerationCollection(Range)) {
2087 // FIXME: Support init-statements in Objective-C++20 ranged for statement.
2088 if (InitStmt)
2089 return Diag(InitStmt->getBeginLoc(), diag::err_objc_for_range_init_stmt)
2090 << InitStmt->getSourceRange();
Sam Panzer2c4ca0f2012-08-16 21:47:25 +00002091 return ActOnObjCForCollectionStmt(ForLoc, First, Range, RParenLoc);
Richard Smith8baa5002018-09-28 18:44:09 +00002092 }
Richard Smith02e85f32011-04-14 22:09:26 +00002093
2094 DeclStmt *DS = dyn_cast<DeclStmt>(First);
2095 assert(DS && "first part of for range not a decl stmt");
2096
2097 if (!DS->isSingleDecl()) {
Stephen Kellya6e43582018-08-09 21:05:56 +00002098 Diag(DS->getBeginLoc(), diag::err_type_defined_in_for_range);
Richard Smith02e85f32011-04-14 22:09:26 +00002099 return StmtError();
2100 }
Richard Smith02e85f32011-04-14 22:09:26 +00002101
Richard Smith3249fed2013-08-21 01:40:36 +00002102 Decl *LoopVar = DS->getSingleDecl();
2103 if (LoopVar->isInvalidDecl() || !Range ||
2104 DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) {
2105 LoopVar->setInvalidDecl();
Richard Smith02e85f32011-04-14 22:09:26 +00002106 return StmtError();
Richard Smith3249fed2013-08-21 01:40:36 +00002107 }
Richard Smith02e85f32011-04-14 22:09:26 +00002108
Eric Fiselierb936a392017-06-14 03:24:55 +00002109 // Build the coroutine state immediately and not later during template
2110 // instantiation
2111 if (!CoawaitLoc.isInvalid()) {
2112 if (!ActOnCoroutineBodyStart(S, CoawaitLoc, "co_await"))
2113 return StmtError();
Richard Smithcfd53b42015-10-22 06:13:50 +00002114 }
2115
Richard Smith02e85f32011-04-14 22:09:26 +00002116 // Build auto && __range = range-init
Matt Davisb8402ef2018-02-14 21:22:11 +00002117 // Divide by 2, since the variables are in the inner scope (loop body).
2118 const auto DepthStr = std::to_string(S->getDepth() / 2);
Stephen Kellyf2ceec42018-08-09 21:08:08 +00002119 SourceLocation RangeLoc = Range->getBeginLoc();
Richard Smith02e85f32011-04-14 22:09:26 +00002120 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc,
2121 Context.getAutoRRefDeductType(),
Matt Davisb8402ef2018-02-14 21:22:11 +00002122 std::string("__range") + DepthStr);
Richard Smith02e85f32011-04-14 22:09:26 +00002123 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc,
Richard Smith3249fed2013-08-21 01:40:36 +00002124 diag::err_for_range_deduction_failure)) {
2125 LoopVar->setInvalidDecl();
Richard Smith02e85f32011-04-14 22:09:26 +00002126 return StmtError();
Richard Smith3249fed2013-08-21 01:40:36 +00002127 }
Richard Smith02e85f32011-04-14 22:09:26 +00002128
2129 // Claim the type doesn't contain auto: we've already done the checking.
2130 DeclGroupPtrTy RangeGroup =
Richard Smith3beb7c62017-01-12 02:27:38 +00002131 BuildDeclaratorGroup(MutableArrayRef<Decl *>((Decl **)&RangeVar, 1));
Richard Smith02e85f32011-04-14 22:09:26 +00002132 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc);
Richard Smith3249fed2013-08-21 01:40:36 +00002133 if (RangeDecl.isInvalid()) {
2134 LoopVar->setInvalidDecl();
Richard Smith02e85f32011-04-14 22:09:26 +00002135 return StmtError();
Richard Smith3249fed2013-08-21 01:40:36 +00002136 }
Richard Smith02e85f32011-04-14 22:09:26 +00002137
Richard Smith8baa5002018-09-28 18:44:09 +00002138 return BuildCXXForRangeStmt(
2139 ForLoc, CoawaitLoc, InitStmt, ColonLoc, RangeDecl.get(),
2140 /*BeginStmt=*/nullptr, /*EndStmt=*/nullptr,
2141 /*Cond=*/nullptr, /*Inc=*/nullptr, DS, RParenLoc, Kind);
Sam Panzer0f384432012-08-21 00:52:01 +00002142}
2143
Adrian Prantl9fc8faf2018-05-09 01:00:01 +00002144/// Create the initialization, compare, and increment steps for
Sam Panzer0f384432012-08-21 00:52:01 +00002145/// the range-based for loop expression.
2146/// This function does not handle array-based for loops,
2147/// which are created in Sema::BuildCXXForRangeStmt.
2148///
2149/// \returns a ForRangeStatus indicating success or what kind of error occurred.
2150/// BeginExpr and EndExpr are set and FRS_Success is returned on success;
2151/// CandidateSet and BEF are set and some non-success value is returned on
2152/// failure.
Eric Fiselierb936a392017-06-14 03:24:55 +00002153static Sema::ForRangeStatus
2154BuildNonArrayForRange(Sema &SemaRef, Expr *BeginRange, Expr *EndRange,
2155 QualType RangeType, VarDecl *BeginVar, VarDecl *EndVar,
2156 SourceLocation ColonLoc, SourceLocation CoawaitLoc,
2157 OverloadCandidateSet *CandidateSet, ExprResult *BeginExpr,
2158 ExprResult *EndExpr, BeginEndFunction *BEF) {
Sam Panzer0f384432012-08-21 00:52:01 +00002159 DeclarationNameInfo BeginNameInfo(
2160 &SemaRef.PP.getIdentifierTable().get("begin"), ColonLoc);
2161 DeclarationNameInfo EndNameInfo(&SemaRef.PP.getIdentifierTable().get("end"),
2162 ColonLoc);
2163
2164 LookupResult BeginMemberLookup(SemaRef, BeginNameInfo,
2165 Sema::LookupMemberName);
2166 LookupResult EndMemberLookup(SemaRef, EndNameInfo, Sema::LookupMemberName);
2167
Richard Smith236ffde2018-09-24 23:17:44 +00002168 auto BuildBegin = [&] {
2169 *BEF = BEF_begin;
2170 Sema::ForRangeStatus RangeStatus =
2171 SemaRef.BuildForRangeBeginEndCall(ColonLoc, ColonLoc, BeginNameInfo,
2172 BeginMemberLookup, CandidateSet,
2173 BeginRange, BeginExpr);
2174
2175 if (RangeStatus != Sema::FRS_Success) {
2176 if (RangeStatus == Sema::FRS_DiagnosticIssued)
2177 SemaRef.Diag(BeginRange->getBeginLoc(), diag::note_in_for_range)
2178 << ColonLoc << BEF_begin << BeginRange->getType();
2179 return RangeStatus;
2180 }
2181 if (!CoawaitLoc.isInvalid()) {
2182 // FIXME: getCurScope() should not be used during template instantiation.
2183 // We should pick up the set of unqualified lookup results for operator
2184 // co_await during the initial parse.
2185 *BeginExpr = SemaRef.ActOnCoawaitExpr(SemaRef.getCurScope(), ColonLoc,
2186 BeginExpr->get());
2187 if (BeginExpr->isInvalid())
2188 return Sema::FRS_DiagnosticIssued;
2189 }
2190 if (FinishForRangeVarDecl(SemaRef, BeginVar, BeginExpr->get(), ColonLoc,
2191 diag::err_for_range_iter_deduction_failure)) {
2192 NoteForRangeBeginEndFunction(SemaRef, BeginExpr->get(), *BEF);
2193 return Sema::FRS_DiagnosticIssued;
2194 }
2195 return Sema::FRS_Success;
2196 };
2197
2198 auto BuildEnd = [&] {
2199 *BEF = BEF_end;
2200 Sema::ForRangeStatus RangeStatus =
2201 SemaRef.BuildForRangeBeginEndCall(ColonLoc, ColonLoc, EndNameInfo,
2202 EndMemberLookup, CandidateSet,
2203 EndRange, EndExpr);
2204 if (RangeStatus != Sema::FRS_Success) {
2205 if (RangeStatus == Sema::FRS_DiagnosticIssued)
2206 SemaRef.Diag(EndRange->getBeginLoc(), diag::note_in_for_range)
2207 << ColonLoc << BEF_end << EndRange->getType();
2208 return RangeStatus;
2209 }
2210 if (FinishForRangeVarDecl(SemaRef, EndVar, EndExpr->get(), ColonLoc,
2211 diag::err_for_range_iter_deduction_failure)) {
2212 NoteForRangeBeginEndFunction(SemaRef, EndExpr->get(), *BEF);
2213 return Sema::FRS_DiagnosticIssued;
2214 }
2215 return Sema::FRS_Success;
2216 };
2217
Sam Panzer0f384432012-08-21 00:52:01 +00002218 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) {
2219 // - if _RangeT is a class type, the unqualified-ids begin and end are
2220 // looked up in the scope of class _RangeT as if by class member access
2221 // lookup (3.4.5), and if either (or both) finds at least one
2222 // declaration, begin-expr and end-expr are __range.begin() and
2223 // __range.end(), respectively;
2224 SemaRef.LookupQualifiedName(BeginMemberLookup, D);
Richard Smith236ffde2018-09-24 23:17:44 +00002225 if (BeginMemberLookup.isAmbiguous())
2226 return Sema::FRS_DiagnosticIssued;
2227
Sam Panzer0f384432012-08-21 00:52:01 +00002228 SemaRef.LookupQualifiedName(EndMemberLookup, D);
Richard Smith236ffde2018-09-24 23:17:44 +00002229 if (EndMemberLookup.isAmbiguous())
2230 return Sema::FRS_DiagnosticIssued;
Sam Panzer0f384432012-08-21 00:52:01 +00002231
2232 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) {
Richard Smith236ffde2018-09-24 23:17:44 +00002233 // Look up the non-member form of the member we didn't find, first.
2234 // This way we prefer a "no viable 'end'" diagnostic over a "i found
2235 // a 'begin' but ignored it because there was no member 'end'"
2236 // diagnostic.
2237 auto BuildNonmember = [&](
2238 BeginEndFunction BEFFound, LookupResult &Found,
2239 llvm::function_ref<Sema::ForRangeStatus()> BuildFound,
2240 llvm::function_ref<Sema::ForRangeStatus()> BuildNotFound) {
2241 LookupResult OldFound = std::move(Found);
2242 Found.clear();
Sam Panzer0f384432012-08-21 00:52:01 +00002243
Richard Smith236ffde2018-09-24 23:17:44 +00002244 if (Sema::ForRangeStatus Result = BuildNotFound())
2245 return Result;
2246
2247 switch (BuildFound()) {
2248 case Sema::FRS_Success:
2249 return Sema::FRS_Success;
2250
2251 case Sema::FRS_NoViableFunction:
2252 SemaRef.Diag(BeginRange->getBeginLoc(), diag::err_for_range_invalid)
2253 << BeginRange->getType() << BEFFound;
2254 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, BeginRange);
2255 LLVM_FALLTHROUGH;
2256
2257 case Sema::FRS_DiagnosticIssued:
2258 for (NamedDecl *D : OldFound) {
2259 SemaRef.Diag(D->getLocation(),
2260 diag::note_for_range_member_begin_end_ignored)
2261 << BeginRange->getType() << BEFFound;
2262 }
2263 return Sema::FRS_DiagnosticIssued;
2264 }
2265 llvm_unreachable("unexpected ForRangeStatus");
2266 };
2267 if (BeginMemberLookup.empty())
2268 return BuildNonmember(BEF_end, EndMemberLookup, BuildEnd, BuildBegin);
2269 return BuildNonmember(BEF_begin, BeginMemberLookup, BuildBegin, BuildEnd);
Sam Panzer0f384432012-08-21 00:52:01 +00002270 }
2271 } else {
2272 // - otherwise, begin-expr and end-expr are begin(__range) and
2273 // end(__range), respectively, where begin and end are looked up with
2274 // argument-dependent lookup (3.4.2). For the purposes of this name
2275 // lookup, namespace std is an associated namespace.
Sam Panzer0f384432012-08-21 00:52:01 +00002276 }
2277
Richard Smith236ffde2018-09-24 23:17:44 +00002278 if (Sema::ForRangeStatus Result = BuildBegin())
2279 return Result;
2280 return BuildEnd();
Sam Panzer0f384432012-08-21 00:52:01 +00002281}
2282
2283/// Speculatively attempt to dereference an invalid range expression.
Richard Smitha05b3b52012-09-20 21:52:32 +00002284/// If the attempt fails, this function will return a valid, null StmtResult
2285/// and emit no diagnostics.
Sam Panzer0f384432012-08-21 00:52:01 +00002286static StmtResult RebuildForRangeWithDereference(Sema &SemaRef, Scope *S,
2287 SourceLocation ForLoc,
Richard Smithcfd53b42015-10-22 06:13:50 +00002288 SourceLocation CoawaitLoc,
Richard Smith8baa5002018-09-28 18:44:09 +00002289 Stmt *InitStmt,
Sam Panzer0f384432012-08-21 00:52:01 +00002290 Stmt *LoopVarDecl,
2291 SourceLocation ColonLoc,
2292 Expr *Range,
2293 SourceLocation RangeLoc,
2294 SourceLocation RParenLoc) {
Richard Smitha05b3b52012-09-20 21:52:32 +00002295 // Determine whether we can rebuild the for-range statement with a
2296 // dereferenced range expression.
2297 ExprResult AdjustedRange;
2298 {
2299 Sema::SFINAETrap Trap(SemaRef);
2300
2301 AdjustedRange = SemaRef.BuildUnaryOp(S, RangeLoc, UO_Deref, Range);
2302 if (AdjustedRange.isInvalid())
2303 return StmtResult();
2304
Richard Smith9f690bd2015-10-27 06:02:45 +00002305 StmtResult SR = SemaRef.ActOnCXXForRangeStmt(
Richard Smith8baa5002018-09-28 18:44:09 +00002306 S, ForLoc, CoawaitLoc, InitStmt, LoopVarDecl, ColonLoc,
2307 AdjustedRange.get(), RParenLoc, Sema::BFRK_Check);
Richard Smitha05b3b52012-09-20 21:52:32 +00002308 if (SR.isInvalid())
2309 return StmtResult();
2310 }
2311
2312 // The attempt to dereference worked well enough that it could produce a valid
2313 // loop. Produce a fixit, and rebuild the loop with diagnostics enabled, in
2314 // case there are any other (non-fatal) problems with it.
2315 SemaRef.Diag(RangeLoc, diag::err_for_range_dereference)
2316 << Range->getType() << FixItHint::CreateInsertion(RangeLoc, "*");
Richard Smith8baa5002018-09-28 18:44:09 +00002317 return SemaRef.ActOnCXXForRangeStmt(
2318 S, ForLoc, CoawaitLoc, InitStmt, LoopVarDecl, ColonLoc,
2319 AdjustedRange.get(), RParenLoc, Sema::BFRK_Rebuild);
Richard Smith02e85f32011-04-14 22:09:26 +00002320}
2321
Richard Smith3249fed2013-08-21 01:40:36 +00002322namespace {
2323/// RAII object to automatically invalidate a declaration if an error occurs.
2324struct InvalidateOnErrorScope {
2325 InvalidateOnErrorScope(Sema &SemaRef, Decl *D, bool Enabled)
2326 : Trap(SemaRef.Diags), D(D), Enabled(Enabled) {}
2327 ~InvalidateOnErrorScope() {
2328 if (Enabled && Trap.hasErrorOccurred())
2329 D->setInvalidDecl();
2330 }
2331
2332 DiagnosticErrorTrap Trap;
2333 Decl *D;
2334 bool Enabled;
2335};
Alexander Kornienkoab9db512015-06-22 23:07:51 +00002336}
Richard Smith3249fed2013-08-21 01:40:36 +00002337
Richard Smitha05b3b52012-09-20 21:52:32 +00002338/// BuildCXXForRangeStmt - Build or instantiate a C++11 for-range statement.
Richard Smith8baa5002018-09-28 18:44:09 +00002339StmtResult Sema::BuildCXXForRangeStmt(SourceLocation ForLoc,
2340 SourceLocation CoawaitLoc, Stmt *InitStmt,
2341 SourceLocation ColonLoc, Stmt *RangeDecl,
2342 Stmt *Begin, Stmt *End, Expr *Cond,
2343 Expr *Inc, Stmt *LoopVarDecl,
2344 SourceLocation RParenLoc,
2345 BuildForRangeKind Kind) {
Richard Smith9f690bd2015-10-27 06:02:45 +00002346 // FIXME: This should not be used during template instantiation. We should
2347 // pick up the set of unqualified lookup results for the != and + operators
2348 // in the initial parse.
2349 //
2350 // Testcase (accepts-invalid):
2351 // template<typename T> void f() { for (auto x : T()) {} }
2352 // namespace N { struct X { X begin(); X end(); int operator*(); }; }
2353 // bool operator!=(N::X, N::X); void operator++(N::X);
2354 // void g() { f<N::X>(); }
Richard Smith02e85f32011-04-14 22:09:26 +00002355 Scope *S = getCurScope();
2356
2357 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl);
2358 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl());
2359 QualType RangeVarType = RangeVar->getType();
2360
2361 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl);
2362 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl());
2363
Richard Smith3249fed2013-08-21 01:40:36 +00002364 // If we hit any errors, mark the loop variable as invalid if its type
2365 // contains 'auto'.
2366 InvalidateOnErrorScope Invalidate(*this, LoopVar,
2367 LoopVar->getType()->isUndeducedType());
2368
Richard Smith01694c32016-03-20 10:33:40 +00002369 StmtResult BeginDeclStmt = Begin;
2370 StmtResult EndDeclStmt = End;
Richard Smith02e85f32011-04-14 22:09:26 +00002371 ExprResult NotEqExpr = Cond, IncrExpr = Inc;
2372
Richard Smith27d807c2013-04-30 13:56:41 +00002373 if (RangeVarType->isDependentType()) {
2374 // The range is implicitly used as a placeholder when it is dependent.
Eli Friedman276dd182013-09-05 00:02:25 +00002375 RangeVar->markUsed(Context);
Richard Smith27d807c2013-04-30 13:56:41 +00002376
2377 // Deduce any 'auto's in the loop variable as 'DependentTy'. We'll fill
2378 // them in properly when we instantiate the loop.
Erik Pilkington21ff3452017-06-12 16:11:06 +00002379 if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) {
2380 if (auto *DD = dyn_cast<DecompositionDecl>(LoopVar))
2381 for (auto *Binding : DD->bindings())
2382 Binding->setType(Context.DependentTy);
Richard Smith27d807c2013-04-30 13:56:41 +00002383 LoopVar->setType(SubstAutoType(LoopVar->getType(), Context.DependentTy));
Erik Pilkington21ff3452017-06-12 16:11:06 +00002384 }
Richard Smith01694c32016-03-20 10:33:40 +00002385 } else if (!BeginDeclStmt.get()) {
Richard Smith02e85f32011-04-14 22:09:26 +00002386 SourceLocation RangeLoc = RangeVar->getLocation();
2387
Ted Kremenekbed648e2011-10-10 22:36:28 +00002388 const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType();
2389
2390 ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
2391 VK_LValue, ColonLoc);
2392 if (BeginRangeRef.isInvalid())
2393 return StmtError();
2394
2395 ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
2396 VK_LValue, ColonLoc);
2397 if (EndRangeRef.isInvalid())
Richard Smith02e85f32011-04-14 22:09:26 +00002398 return StmtError();
2399
2400 QualType AutoType = Context.getAutoDeductType();
2401 Expr *Range = RangeVar->getInit();
2402 if (!Range)
2403 return StmtError();
2404 QualType RangeType = Range->getType();
2405
2406 if (RequireCompleteType(RangeLoc, RangeType,
Douglas Gregor7bfb2d02012-05-04 16:32:21 +00002407 diag::err_for_range_incomplete_type))
Richard Smith02e85f32011-04-14 22:09:26 +00002408 return StmtError();
2409
2410 // Build auto __begin = begin-expr, __end = end-expr.
Matt Davisb8402ef2018-02-14 21:22:11 +00002411 // Divide by 2, since the variables are in the inner scope (loop body).
2412 const auto DepthStr = std::to_string(S->getDepth() / 2);
Richard Smith02e85f32011-04-14 22:09:26 +00002413 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType,
Matt Davisb8402ef2018-02-14 21:22:11 +00002414 std::string("__begin") + DepthStr);
Richard Smith02e85f32011-04-14 22:09:26 +00002415 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType,
Matt Davisb8402ef2018-02-14 21:22:11 +00002416 std::string("__end") + DepthStr);
Richard Smith02e85f32011-04-14 22:09:26 +00002417
2418 // Build begin-expr and end-expr and attach to __begin and __end variables.
2419 ExprResult BeginExpr, EndExpr;
2420 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) {
2421 // - if _RangeT is an array type, begin-expr and end-expr are __range and
2422 // __range + __bound, respectively, where __bound is the array bound. If
2423 // _RangeT is an array of unknown size or an array of incomplete type,
2424 // the program is ill-formed;
2425
2426 // begin-expr is __range.
Ted Kremenekbed648e2011-10-10 22:36:28 +00002427 BeginExpr = BeginRangeRef;
Eric Fiselierb936a392017-06-14 03:24:55 +00002428 if (!CoawaitLoc.isInvalid()) {
2429 BeginExpr = ActOnCoawaitExpr(S, ColonLoc, BeginExpr.get());
2430 if (BeginExpr.isInvalid())
2431 return StmtError();
2432 }
Ted Kremenekbed648e2011-10-10 22:36:28 +00002433 if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc,
Richard Smith02e85f32011-04-14 22:09:26 +00002434 diag::err_for_range_iter_deduction_failure)) {
2435 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2436 return StmtError();
2437 }
2438
2439 // Find the array bound.
2440 ExprResult BoundExpr;
2441 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT))
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00002442 BoundExpr = IntegerLiteral::Create(
2443 Context, CAT->getSize(), Context.getPointerDiffType(), RangeLoc);
Richard Smith02e85f32011-04-14 22:09:26 +00002444 else if (const VariableArrayType *VAT =
Faisal Vali1ca2d962017-05-15 01:49:19 +00002445 dyn_cast<VariableArrayType>(UnqAT)) {
2446 // For a variably modified type we can't just use the expression within
2447 // the array bounds, since we don't want that to be re-evaluated here.
2448 // Rather, we need to determine what it was when the array was first
2449 // created - so we resort to using sizeof(vla)/sizeof(element).
2450 // For e.g.
Fangrui Song6907ce22018-07-30 19:24:48 +00002451 // void f(int b) {
Faisal Vali1ca2d962017-05-15 01:49:19 +00002452 // int vla[b];
2453 // b = -1; <-- This should not affect the num of iterations below
2454 // for (int &c : vla) { .. }
2455 // }
2456
2457 // FIXME: This results in codegen generating IR that recalculates the
2458 // run-time number of elements (as opposed to just using the IR Value
2459 // that corresponds to the run-time value of each bound that was
Alexander Kornienko2a8c18d2018-04-06 15:14:32 +00002460 // generated when the array was created.) If this proves too embarrassing
Faisal Vali1ca2d962017-05-15 01:49:19 +00002461 // even for unoptimized IR, consider passing a magic-value/cookie to
2462 // codegen that then knows to simply use that initial llvm::Value (that
2463 // corresponds to the bound at time of array creation) within
2464 // getelementptr. But be prepared to pay the price of increasing a
2465 // customized form of coupling between the two components - which could
2466 // be hard to maintain as the codebase evolves.
2467
2468 ExprResult SizeOfVLAExprR = ActOnUnaryExprOrTypeTraitExpr(
2469 EndVar->getLocation(), UETT_SizeOf,
2470 /*isType=*/true,
2471 CreateParsedType(VAT->desugar(), Context.getTrivialTypeSourceInfo(
2472 VAT->desugar(), RangeLoc))
2473 .getAsOpaquePtr(),
2474 EndVar->getSourceRange());
2475 if (SizeOfVLAExprR.isInvalid())
2476 return StmtError();
Fangrui Song6907ce22018-07-30 19:24:48 +00002477
Faisal Vali1ca2d962017-05-15 01:49:19 +00002478 ExprResult SizeOfEachElementExprR = ActOnUnaryExprOrTypeTraitExpr(
2479 EndVar->getLocation(), UETT_SizeOf,
2480 /*isType=*/true,
2481 CreateParsedType(VAT->desugar(),
2482 Context.getTrivialTypeSourceInfo(
2483 VAT->getElementType(), RangeLoc))
2484 .getAsOpaquePtr(),
2485 EndVar->getSourceRange());
2486 if (SizeOfEachElementExprR.isInvalid())
2487 return StmtError();
2488
2489 BoundExpr =
2490 ActOnBinOp(S, EndVar->getLocation(), tok::slash,
2491 SizeOfVLAExprR.get(), SizeOfEachElementExprR.get());
2492 if (BoundExpr.isInvalid())
2493 return StmtError();
Fangrui Song6907ce22018-07-30 19:24:48 +00002494
Faisal Vali1ca2d962017-05-15 01:49:19 +00002495 } else {
Richard Smith02e85f32011-04-14 22:09:26 +00002496 // Can't be a DependentSizedArrayType or an IncompleteArrayType since
2497 // UnqAT is not incomplete and Range is not type-dependent.
David Blaikie83d382b2011-09-23 05:06:16 +00002498 llvm_unreachable("Unexpected array type in for-range");
Richard Smith02e85f32011-04-14 22:09:26 +00002499 }
2500
2501 // end-expr is __range + __bound.
Ted Kremenekbed648e2011-10-10 22:36:28 +00002502 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(),
Richard Smith02e85f32011-04-14 22:09:26 +00002503 BoundExpr.get());
2504 if (EndExpr.isInvalid())
2505 return StmtError();
2506 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc,
2507 diag::err_for_range_iter_deduction_failure)) {
2508 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2509 return StmtError();
2510 }
2511 } else {
Richard Smith100b24a2014-04-17 01:52:14 +00002512 OverloadCandidateSet CandidateSet(RangeLoc,
2513 OverloadCandidateSet::CSK_Normal);
Richard Smith9f690bd2015-10-27 06:02:45 +00002514 BeginEndFunction BEFFailure;
Eric Fiselierb936a392017-06-14 03:24:55 +00002515 ForRangeStatus RangeStatus = BuildNonArrayForRange(
2516 *this, BeginRangeRef.get(), EndRangeRef.get(), RangeType, BeginVar,
2517 EndVar, ColonLoc, CoawaitLoc, &CandidateSet, &BeginExpr, &EndExpr,
2518 &BEFFailure);
Richard Smith02e85f32011-04-14 22:09:26 +00002519
Richard Smitha05b3b52012-09-20 21:52:32 +00002520 if (Kind == BFRK_Build && RangeStatus == FRS_NoViableFunction &&
Sam Panzer0f384432012-08-21 00:52:01 +00002521 BEFFailure == BEF_begin) {
Richard Trieu08254692013-10-11 22:16:04 +00002522 // If the range is being built from an array parameter, emit a
2523 // a diagnostic that it is being treated as a pointer.
2524 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Range)) {
2525 if (ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
2526 QualType ArrayTy = PVD->getOriginalType();
2527 QualType PointerTy = PVD->getType();
2528 if (PointerTy->isPointerType() && ArrayTy->isArrayType()) {
Stephen Kellyf2ceec42018-08-09 21:08:08 +00002529 Diag(Range->getBeginLoc(), diag::err_range_on_array_parameter)
2530 << RangeLoc << PVD << ArrayTy << PointerTy;
Richard Trieu08254692013-10-11 22:16:04 +00002531 Diag(PVD->getLocation(), diag::note_declared_at);
2532 return StmtError();
2533 }
2534 }
2535 }
2536
2537 // If building the range failed, try dereferencing the range expression
2538 // unless a diagnostic was issued or the end function is problematic.
Sam Panzer0f384432012-08-21 00:52:01 +00002539 StmtResult SR = RebuildForRangeWithDereference(*this, S, ForLoc,
Richard Smith8baa5002018-09-28 18:44:09 +00002540 CoawaitLoc, InitStmt,
Sam Panzer0f384432012-08-21 00:52:01 +00002541 LoopVarDecl, ColonLoc,
2542 Range, RangeLoc,
2543 RParenLoc);
Richard Smitha05b3b52012-09-20 21:52:32 +00002544 if (SR.isInvalid() || SR.isUsable())
Sam Panzer0f384432012-08-21 00:52:01 +00002545 return SR;
Richard Smith02e85f32011-04-14 22:09:26 +00002546 }
2547
Sam Panzer0f384432012-08-21 00:52:01 +00002548 // Otherwise, emit diagnostics if we haven't already.
2549 if (RangeStatus == FRS_NoViableFunction) {
Richard Smitha05b3b52012-09-20 21:52:32 +00002550 Expr *Range = BEFFailure ? EndRangeRef.get() : BeginRangeRef.get();
Stephen Kellyf2ceec42018-08-09 21:08:08 +00002551 Diag(Range->getBeginLoc(), diag::err_for_range_invalid)
Sam Panzer0f384432012-08-21 00:52:01 +00002552 << RangeLoc << Range->getType() << BEFFailure;
Nico Webera2a0eb92012-12-29 20:03:39 +00002553 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Range);
Sam Panzer0f384432012-08-21 00:52:01 +00002554 }
2555 // Return an error if no fix was discovered.
2556 if (RangeStatus != FRS_Success)
Richard Smith02e85f32011-04-14 22:09:26 +00002557 return StmtError();
2558 }
2559
Sam Panzer0f384432012-08-21 00:52:01 +00002560 assert(!BeginExpr.isInvalid() && !EndExpr.isInvalid() &&
2561 "invalid range expression in for loop");
2562
2563 // C++11 [dcl.spec.auto]p7: BeginType and EndType must be the same.
Richard Smith01694c32016-03-20 10:33:40 +00002564 // C++1z removes this restriction.
Richard Smith02e85f32011-04-14 22:09:26 +00002565 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType();
2566 if (!Context.hasSameType(BeginType, EndType)) {
Aaron Ballmanc351fba2017-12-04 20:27:34 +00002567 Diag(RangeLoc, getLangOpts().CPlusPlus17
Richard Smith01694c32016-03-20 10:33:40 +00002568 ? diag::warn_for_range_begin_end_types_differ
2569 : diag::ext_for_range_begin_end_types_differ)
2570 << BeginType << EndType;
Richard Smith02e85f32011-04-14 22:09:26 +00002571 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2572 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2573 }
2574
Richard Smith01694c32016-03-20 10:33:40 +00002575 BeginDeclStmt =
2576 ActOnDeclStmt(ConvertDeclToDeclGroup(BeginVar), ColonLoc, ColonLoc);
2577 EndDeclStmt =
2578 ActOnDeclStmt(ConvertDeclToDeclGroup(EndVar), ColonLoc, ColonLoc);
Richard Smith02e85f32011-04-14 22:09:26 +00002579
Ted Kremenekbed648e2011-10-10 22:36:28 +00002580 const QualType BeginRefNonRefType = BeginType.getNonReferenceType();
2581 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
Richard Smith02e85f32011-04-14 22:09:26 +00002582 VK_LValue, ColonLoc);
Ted Kremenekbed648e2011-10-10 22:36:28 +00002583 if (BeginRef.isInvalid())
2584 return StmtError();
2585
Richard Smith02e85f32011-04-14 22:09:26 +00002586 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(),
2587 VK_LValue, ColonLoc);
Ted Kremenekbed648e2011-10-10 22:36:28 +00002588 if (EndRef.isInvalid())
2589 return StmtError();
Richard Smith02e85f32011-04-14 22:09:26 +00002590
2591 // Build and check __begin != __end expression.
2592 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal,
2593 BeginRef.get(), EndRef.get());
Richard Smith03a4aa32016-06-23 19:02:52 +00002594 if (!NotEqExpr.isInvalid())
2595 NotEqExpr = CheckBooleanCondition(ColonLoc, NotEqExpr.get());
2596 if (!NotEqExpr.isInvalid())
2597 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get());
Richard Smith02e85f32011-04-14 22:09:26 +00002598 if (NotEqExpr.isInvalid()) {
Sam Panzer22a3fe12012-09-06 21:50:08 +00002599 Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2600 << RangeLoc << 0 << BeginRangeRef.get()->getType();
Richard Smith02e85f32011-04-14 22:09:26 +00002601 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2602 if (!Context.hasSameType(BeginType, EndType))
2603 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2604 return StmtError();
2605 }
2606
2607 // Build and check ++__begin expression.
Ted Kremenekbed648e2011-10-10 22:36:28 +00002608 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2609 VK_LValue, ColonLoc);
2610 if (BeginRef.isInvalid())
2611 return StmtError();
2612
Richard Smith02e85f32011-04-14 22:09:26 +00002613 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get());
Richard Smithcfd53b42015-10-22 06:13:50 +00002614 if (!IncrExpr.isInvalid() && CoawaitLoc.isValid())
Eric Fiselierb936a392017-06-14 03:24:55 +00002615 // FIXME: getCurScope() should not be used during template instantiation.
2616 // We should pick up the set of unqualified lookup results for operator
2617 // co_await during the initial parse.
Richard Smith9f690bd2015-10-27 06:02:45 +00002618 IncrExpr = ActOnCoawaitExpr(S, CoawaitLoc, IncrExpr.get());
Richard Smithcfd53b42015-10-22 06:13:50 +00002619 if (!IncrExpr.isInvalid())
2620 IncrExpr = ActOnFinishFullExpr(IncrExpr.get());
Richard Smith02e85f32011-04-14 22:09:26 +00002621 if (IncrExpr.isInvalid()) {
Sam Panzer22a3fe12012-09-06 21:50:08 +00002622 Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2623 << RangeLoc << 2 << BeginRangeRef.get()->getType() ;
Richard Smith02e85f32011-04-14 22:09:26 +00002624 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2625 return StmtError();
2626 }
2627
2628 // Build and check *__begin expression.
Ted Kremenekbed648e2011-10-10 22:36:28 +00002629 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2630 VK_LValue, ColonLoc);
2631 if (BeginRef.isInvalid())
2632 return StmtError();
2633
Richard Smith02e85f32011-04-14 22:09:26 +00002634 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get());
2635 if (DerefExpr.isInvalid()) {
Sam Panzer22a3fe12012-09-06 21:50:08 +00002636 Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2637 << RangeLoc << 1 << BeginRangeRef.get()->getType();
Richard Smith02e85f32011-04-14 22:09:26 +00002638 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2639 return StmtError();
2640 }
2641
Richard Smitha05b3b52012-09-20 21:52:32 +00002642 // Attach *__begin as initializer for VD. Don't touch it if we're just
2643 // trying to determine whether this would be a valid range.
2644 if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) {
Richard Smith3beb7c62017-01-12 02:27:38 +00002645 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false);
Richard Smith02e85f32011-04-14 22:09:26 +00002646 if (LoopVar->isInvalidDecl())
2647 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2648 }
2649 }
2650
Richard Smitha05b3b52012-09-20 21:52:32 +00002651 // Don't bother to actually allocate the result if we're just trying to
2652 // determine whether it would be valid.
2653 if (Kind == BFRK_Check)
2654 return StmtResult();
2655
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00002656 return new (Context) CXXForRangeStmt(
Richard Smith8baa5002018-09-28 18:44:09 +00002657 InitStmt, RangeDS, cast_or_null<DeclStmt>(BeginDeclStmt.get()),
Richard Smith01694c32016-03-20 10:33:40 +00002658 cast_or_null<DeclStmt>(EndDeclStmt.get()), NotEqExpr.get(),
Richard Smith9f690bd2015-10-27 06:02:45 +00002659 IncrExpr.get(), LoopVarDS, /*Body=*/nullptr, ForLoc, CoawaitLoc,
2660 ColonLoc, RParenLoc);
Richard Smith02e85f32011-04-14 22:09:26 +00002661}
2662
Chad Rosier02a84392012-08-10 17:56:09 +00002663/// FinishObjCForCollectionStmt - Attach the body to a objective-C foreach
Fariborz Jahanian450bb6e2012-07-03 22:00:52 +00002664/// statement.
2665StmtResult Sema::FinishObjCForCollectionStmt(Stmt *S, Stmt *B) {
2666 if (!S || !B)
2667 return StmtError();
2668 ObjCForCollectionStmt * ForStmt = cast<ObjCForCollectionStmt>(S);
Chad Rosier02a84392012-08-10 17:56:09 +00002669
Fariborz Jahanian450bb6e2012-07-03 22:00:52 +00002670 ForStmt->setBody(B);
2671 return S;
2672}
2673
Richard Trieu3e1d4832015-04-13 22:08:55 +00002674// Warn when the loop variable is a const reference that creates a copy.
2675// Suggest using the non-reference type for copies. If a copy can be prevented
2676// suggest the const reference type that would do so.
2677// For instance, given "for (const &Foo : Range)", suggest
2678// "for (const Foo : Range)" to denote a copy is made for the loop. If
2679// possible, also suggest "for (const &Bar : Range)" if this type prevents
2680// the copy altogether.
2681static void DiagnoseForRangeReferenceVariableCopies(Sema &SemaRef,
2682 const VarDecl *VD,
2683 QualType RangeInitType) {
2684 const Expr *InitExpr = VD->getInit();
2685 if (!InitExpr)
2686 return;
2687
2688 QualType VariableType = VD->getType();
2689
Tim Shen4a05bb82016-06-21 20:29:17 +00002690 if (auto Cleanups = dyn_cast<ExprWithCleanups>(InitExpr))
2691 if (!Cleanups->cleanupsHaveSideEffects())
2692 InitExpr = Cleanups->getSubExpr();
2693
Richard Trieu3e1d4832015-04-13 22:08:55 +00002694 const MaterializeTemporaryExpr *MTE =
2695 dyn_cast<MaterializeTemporaryExpr>(InitExpr);
2696
2697 // No copy made.
2698 if (!MTE)
2699 return;
2700
2701 const Expr *E = MTE->GetTemporaryExpr()->IgnoreImpCasts();
2702
2703 // Searching for either UnaryOperator for dereference of a pointer or
2704 // CXXOperatorCallExpr for handling iterators.
2705 while (!isa<CXXOperatorCallExpr>(E) && !isa<UnaryOperator>(E)) {
2706 if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(E)) {
2707 E = CCE->getArg(0);
2708 } else if (const CXXMemberCallExpr *Call = dyn_cast<CXXMemberCallExpr>(E)) {
2709 const MemberExpr *ME = cast<MemberExpr>(Call->getCallee());
2710 E = ME->getBase();
2711 } else {
2712 const MaterializeTemporaryExpr *MTE = cast<MaterializeTemporaryExpr>(E);
2713 E = MTE->GetTemporaryExpr();
2714 }
2715 E = E->IgnoreImpCasts();
2716 }
2717
2718 bool ReturnsReference = false;
2719 if (isa<UnaryOperator>(E)) {
2720 ReturnsReference = true;
2721 } else {
2722 const CXXOperatorCallExpr *Call = cast<CXXOperatorCallExpr>(E);
2723 const FunctionDecl *FD = Call->getDirectCallee();
2724 QualType ReturnType = FD->getReturnType();
2725 ReturnsReference = ReturnType->isReferenceType();
2726 }
2727
2728 if (ReturnsReference) {
2729 // Loop variable creates a temporary. Suggest either to go with
Alexander Kornienko2a8c18d2018-04-06 15:14:32 +00002730 // non-reference loop variable to indicate a copy is made, or
Richard Trieu3e1d4832015-04-13 22:08:55 +00002731 // the correct time to bind a const reference.
2732 SemaRef.Diag(VD->getLocation(), diag::warn_for_range_const_reference_copy)
2733 << VD << VariableType << E->getType();
2734 QualType NonReferenceType = VariableType.getNonReferenceType();
2735 NonReferenceType.removeLocalConst();
2736 QualType NewReferenceType =
2737 SemaRef.Context.getLValueReferenceType(E->getType().withConst());
Stephen Kellyf2ceec42018-08-09 21:08:08 +00002738 SemaRef.Diag(VD->getBeginLoc(), diag::note_use_type_or_non_reference)
Richard Trieu3e1d4832015-04-13 22:08:55 +00002739 << NonReferenceType << NewReferenceType << VD->getSourceRange();
2740 } else {
2741 // The range always returns a copy, so a temporary is always created.
2742 // Suggest removing the reference from the loop variable.
2743 SemaRef.Diag(VD->getLocation(), diag::warn_for_range_variable_always_copy)
2744 << VD << RangeInitType;
2745 QualType NonReferenceType = VariableType.getNonReferenceType();
2746 NonReferenceType.removeLocalConst();
Stephen Kellyf2ceec42018-08-09 21:08:08 +00002747 SemaRef.Diag(VD->getBeginLoc(), diag::note_use_non_reference_type)
Richard Trieu3e1d4832015-04-13 22:08:55 +00002748 << NonReferenceType << VD->getSourceRange();
2749 }
2750}
2751
2752// Warns when the loop variable can be changed to a reference type to
2753// prevent a copy. For instance, if given "for (const Foo x : Range)" suggest
2754// "for (const Foo &x : Range)" if this form does not make a copy.
2755static void DiagnoseForRangeConstVariableCopies(Sema &SemaRef,
2756 const VarDecl *VD) {
2757 const Expr *InitExpr = VD->getInit();
2758 if (!InitExpr)
2759 return;
2760
2761 QualType VariableType = VD->getType();
2762
2763 if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(InitExpr)) {
2764 if (!CE->getConstructor()->isCopyConstructor())
2765 return;
2766 } else if (const CastExpr *CE = dyn_cast<CastExpr>(InitExpr)) {
2767 if (CE->getCastKind() != CK_LValueToRValue)
2768 return;
2769 } else {
2770 return;
2771 }
2772
2773 // TODO: Determine a maximum size that a POD type can be before a diagnostic
2774 // should be emitted. Also, only ignore POD types with trivial copy
2775 // constructors.
2776 if (VariableType.isPODType(SemaRef.Context))
2777 return;
2778
2779 // Suggest changing from a const variable to a const reference variable
2780 // if doing so will prevent a copy.
2781 SemaRef.Diag(VD->getLocation(), diag::warn_for_range_copy)
2782 << VD << VariableType << InitExpr->getType();
Stephen Kellyf2ceec42018-08-09 21:08:08 +00002783 SemaRef.Diag(VD->getBeginLoc(), diag::note_use_reference_type)
Richard Trieu3e1d4832015-04-13 22:08:55 +00002784 << SemaRef.Context.getLValueReferenceType(VariableType)
2785 << VD->getSourceRange();
2786}
2787
2788/// DiagnoseForRangeVariableCopies - Diagnose three cases and fixes for them.
2789/// 1) for (const foo &x : foos) where foos only returns a copy. Suggest
2790/// using "const foo x" to show that a copy is made
Alexander Kornienko2a8c18d2018-04-06 15:14:32 +00002791/// 2) for (const bar &x : foos) where bar is a temporary initialized by bar.
Richard Trieu3e1d4832015-04-13 22:08:55 +00002792/// Suggest either "const bar x" to keep the copying or "const foo& x" to
2793/// prevent the copy.
2794/// 3) for (const foo x : foos) where x is constructed from a reference foo.
2795/// Suggest "const foo &x" to prevent the copy.
2796static void DiagnoseForRangeVariableCopies(Sema &SemaRef,
2797 const CXXForRangeStmt *ForStmt) {
2798 if (SemaRef.Diags.isIgnored(diag::warn_for_range_const_reference_copy,
Stephen Kellyf2ceec42018-08-09 21:08:08 +00002799 ForStmt->getBeginLoc()) &&
Richard Trieu3e1d4832015-04-13 22:08:55 +00002800 SemaRef.Diags.isIgnored(diag::warn_for_range_variable_always_copy,
Stephen Kellyf2ceec42018-08-09 21:08:08 +00002801 ForStmt->getBeginLoc()) &&
Richard Trieu3e1d4832015-04-13 22:08:55 +00002802 SemaRef.Diags.isIgnored(diag::warn_for_range_copy,
Stephen Kellyf2ceec42018-08-09 21:08:08 +00002803 ForStmt->getBeginLoc())) {
Richard Trieu3e1d4832015-04-13 22:08:55 +00002804 return;
2805 }
2806
2807 const VarDecl *VD = ForStmt->getLoopVariable();
2808 if (!VD)
2809 return;
2810
2811 QualType VariableType = VD->getType();
2812
2813 if (VariableType->isIncompleteType())
2814 return;
2815
2816 const Expr *InitExpr = VD->getInit();
2817 if (!InitExpr)
2818 return;
2819
2820 if (VariableType->isReferenceType()) {
2821 DiagnoseForRangeReferenceVariableCopies(SemaRef, VD,
2822 ForStmt->getRangeInit()->getType());
2823 } else if (VariableType.isConstQualified()) {
2824 DiagnoseForRangeConstVariableCopies(SemaRef, VD);
2825 }
2826}
2827
Richard Smith02e85f32011-04-14 22:09:26 +00002828/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement.
2829/// This is a separate step from ActOnCXXForRangeStmt because analysis of the
2830/// body cannot be performed until after the type of the range variable is
2831/// determined.
2832StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) {
2833 if (!S || !B)
2834 return StmtError();
2835
Fariborz Jahanian00213472012-07-06 19:04:04 +00002836 if (isa<ObjCForCollectionStmt>(S))
2837 return FinishObjCForCollectionStmt(S, B);
Chad Rosier02a84392012-08-10 17:56:09 +00002838
Dmitri Gribenko800ddf32012-02-14 22:14:32 +00002839 CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S);
2840 ForStmt->setBody(B);
2841
2842 DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B,
2843 diag::warn_empty_range_based_for_body);
2844
Richard Trieu3e1d4832015-04-13 22:08:55 +00002845 DiagnoseForRangeVariableCopies(*this, ForStmt);
2846
Richard Smith02e85f32011-04-14 22:09:26 +00002847 return S;
2848}
2849
Chris Lattnercab02a62011-02-17 20:34:02 +00002850StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc,
2851 SourceLocation LabelLoc,
2852 LabelDecl *TheDecl) {
Reid Kleckner87a31802018-03-12 21:43:02 +00002853 setFunctionHasBranchIntoScope();
Eli Friedman276dd182013-09-05 00:02:25 +00002854 TheDecl->markUsed(Context);
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00002855 return new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc);
Chris Lattneraf8d5812006-11-10 05:07:45 +00002856}
Chris Lattner1c310502007-05-31 06:00:00 +00002857
John McCalldadc5752010-08-24 06:29:42 +00002858StmtResult
Chris Lattner34d9a512009-04-19 01:04:21 +00002859Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc,
John McCallb268a282010-08-23 23:25:46 +00002860 Expr *E) {
Eli Friedman8d7ff402009-03-26 00:18:06 +00002861 // Convert operand to void*
Douglas Gregor30776d42009-05-16 00:20:29 +00002862 if (!E->isTypeDependent()) {
2863 QualType ETy = E->getType();
Chandler Carruth00216982010-01-31 10:26:25 +00002864 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst());
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00002865 ExprResult ExprRes = E;
Douglas Gregor30776d42009-05-16 00:20:29 +00002866 AssignConvertType ConvTy =
John Wiegley01296292011-04-08 18:41:53 +00002867 CheckSingleAssignmentConstraints(DestTy, ExprRes);
2868 if (ExprRes.isInvalid())
2869 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00002870 E = ExprRes.get();
Chandler Carruth00216982010-01-31 10:26:25 +00002871 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing))
Douglas Gregor30776d42009-05-16 00:20:29 +00002872 return StmtError();
2873 }
John McCalla95172b2010-08-01 00:26:45 +00002874
Richard Smith945f8d32013-01-14 22:39:08 +00002875 ExprResult ExprRes = ActOnFinishFullExpr(E);
2876 if (ExprRes.isInvalid())
2877 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00002878 E = ExprRes.get();
Richard Smith945f8d32013-01-14 22:39:08 +00002879
Reid Kleckner87a31802018-03-12 21:43:02 +00002880 setFunctionHasIndirectGoto();
John McCalla95172b2010-08-01 00:26:45 +00002881
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00002882 return new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E);
Chris Lattneraf8d5812006-11-10 05:07:45 +00002883}
2884
Nico Weberd64657f2015-03-09 02:47:59 +00002885static void CheckJumpOutOfSEHFinally(Sema &S, SourceLocation Loc,
2886 const Scope &DestScope) {
2887 if (!S.CurrentSEHFinally.empty() &&
2888 DestScope.Contains(*S.CurrentSEHFinally.back())) {
2889 S.Diag(Loc, diag::warn_jump_out_of_seh_finally);
2890 }
2891}
2892
John McCalldadc5752010-08-24 06:29:42 +00002893StmtResult
Steve Naroff66356bd2007-09-16 14:56:35 +00002894Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) {
Chris Lattnereaafe1222006-11-10 05:17:58 +00002895 Scope *S = CurScope->getContinueParent();
2896 if (!S) {
2897 // C99 6.8.6.2p1: A break shall appear only in or as a loop body.
Sebastian Redl573feed2009-01-18 13:19:59 +00002898 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop));
Chris Lattnereaafe1222006-11-10 05:17:58 +00002899 }
Nico Weberd64657f2015-03-09 02:47:59 +00002900 CheckJumpOutOfSEHFinally(*this, ContinueLoc, *S);
Sebastian Redl573feed2009-01-18 13:19:59 +00002901
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00002902 return new (Context) ContinueStmt(ContinueLoc);
Chris Lattneraf8d5812006-11-10 05:07:45 +00002903}
2904
John McCalldadc5752010-08-24 06:29:42 +00002905StmtResult
Steve Naroff66356bd2007-09-16 14:56:35 +00002906Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) {
Chris Lattnereaafe1222006-11-10 05:17:58 +00002907 Scope *S = CurScope->getBreakParent();
2908 if (!S) {
2909 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body.
Sebastian Redl573feed2009-01-18 13:19:59 +00002910 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch));
Chris Lattnereaafe1222006-11-10 05:17:58 +00002911 }
Alexander Musmana8e9d2e2014-06-03 10:16:47 +00002912 if (S->isOpenMPLoopScope())
2913 return StmtError(Diag(BreakLoc, diag::err_omp_loop_cannot_use_stmt)
2914 << "break");
Nico Weberd64657f2015-03-09 02:47:59 +00002915 CheckJumpOutOfSEHFinally(*this, BreakLoc, *S);
Sebastian Redl573feed2009-01-18 13:19:59 +00002916
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00002917 return new (Context) BreakStmt(BreakLoc);
Chris Lattneraf8d5812006-11-10 05:07:45 +00002918}
2919
Adrian Prantl9fc8faf2018-05-09 01:00:01 +00002920/// Determine whether the given expression is a candidate for
Douglas Gregor5d369002011-01-21 18:05:27 +00002921/// copy elision in either a return statement or a throw expression.
Douglas Gregor6fd1b182010-05-15 06:01:05 +00002922///
Douglas Gregor5d369002011-01-21 18:05:27 +00002923/// \param ReturnType If we're determining the copy elision candidate for
2924/// a return statement, this is the return type of the function. If we're
2925/// determining the copy elision candidate for a throw expression, this will
2926/// be a NULL type.
Douglas Gregor6fd1b182010-05-15 06:01:05 +00002927///
Douglas Gregor5d369002011-01-21 18:05:27 +00002928/// \param E The expression being returned from the function or block, or
2929/// being thrown.
Douglas Gregor6fd1b182010-05-15 06:01:05 +00002930///
Richard Trieu09c163b2018-03-15 03:00:55 +00002931/// \param CESK Whether we allow function parameters or
Erik Pilkingtonfc235eb2016-06-30 23:09:13 +00002932/// id-expressions that could be moved out of the function to be considered NRVO
2933/// candidates. C++ prohibits these for NRVO itself, but we re-use this logic to
2934/// determine whether we should try to move as part of a return or throw (which
2935/// does allow function parameters).
Douglas Gregor6fd1b182010-05-15 06:01:05 +00002936///
2937/// \returns The NRVO candidate variable, if the return statement may use the
2938/// NRVO, or NULL if there is no such candidate.
Erik Pilkingtonfc235eb2016-06-30 23:09:13 +00002939VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, Expr *E,
Richard Trieu09c163b2018-03-15 03:00:55 +00002940 CopyElisionSemanticsKind CESK) {
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002941 // - in a return statement in a function [where] ...
2942 // ... the expression is the name of a non-volatile automatic object ...
2943 DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens());
Alexey Bataev19acc3d2015-01-12 10:17:46 +00002944 if (!DR || DR->refersToEnclosingVariableOrCapture())
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002945 return nullptr;
2946 VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
2947 if (!VD)
2948 return nullptr;
2949
Richard Trieu09c163b2018-03-15 03:00:55 +00002950 if (isCopyElisionCandidate(ReturnType, VD, CESK))
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002951 return VD;
2952 return nullptr;
2953}
2954
2955bool Sema::isCopyElisionCandidate(QualType ReturnType, const VarDecl *VD,
Richard Trieu09c163b2018-03-15 03:00:55 +00002956 CopyElisionSemanticsKind CESK) {
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002957 QualType VDType = VD->getType();
Douglas Gregor222cf0e2010-05-15 00:13:29 +00002958 // - in a return statement in a function with ...
2959 // ... a class return type ...
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002960 if (!ReturnType.isNull() && !ReturnType->isDependentType()) {
Douglas Gregor5d369002011-01-21 18:05:27 +00002961 if (!ReturnType->isRecordType())
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002962 return false;
Douglas Gregor5d369002011-01-21 18:05:27 +00002963 // ... the same cv-unqualified type as the function return type ...
Erik Pilkingtonfc235eb2016-06-30 23:09:13 +00002964 // When considering moving this expression out, allow dissimilar types.
Richard Trieu09c163b2018-03-15 03:00:55 +00002965 if (!(CESK & CES_AllowDifferentTypes) && !VDType->isDependentType() &&
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002966 !Context.hasSameUnqualifiedType(ReturnType, VDType))
2967 return false;
Douglas Gregor5d369002011-01-21 18:05:27 +00002968 }
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00002969
John McCall03318c12011-11-11 03:57:31 +00002970 // ...object (other than a function or catch-clause parameter)...
2971 if (VD->getKind() != Decl::Var &&
Richard Trieu09c163b2018-03-15 03:00:55 +00002972 !((CESK & CES_AllowParameters) && VD->getKind() == Decl::ParmVar))
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002973 return false;
Malcolm Parsons321f24e2018-04-12 14:48:48 +00002974 if (!(CESK & CES_AllowExceptionVariables) && VD->isExceptionVariable())
2975 return false;
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00002976
John McCall03318c12011-11-11 03:57:31 +00002977 // ...automatic...
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002978 if (!VD->hasLocalStorage()) return false;
John McCall03318c12011-11-11 03:57:31 +00002979
Akira Hatanaka6697eff2017-02-15 05:15:28 +00002980 // Return false if VD is a __block variable. We don't want to implicitly move
2981 // out of a __block variable during a return because we cannot assume the
2982 // variable will no longer be used.
2983 if (VD->hasAttr<BlocksAttr>()) return false;
2984
Richard Trieu09c163b2018-03-15 03:00:55 +00002985 if (CESK & CES_AllowDifferentTypes)
Erik Pilkingtonfc235eb2016-06-30 23:09:13 +00002986 return true;
2987
John McCall03318c12011-11-11 03:57:31 +00002988 // ...non-volatile...
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002989 if (VD->getType().isVolatileQualified()) return false;
John McCall03318c12011-11-11 03:57:31 +00002990
John McCall03318c12011-11-11 03:57:31 +00002991 // Variables with higher required alignment than their type's ABI
2992 // alignment cannot use NRVO.
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002993 if (!VD->getType()->isDependentType() && VD->hasAttr<AlignedAttr>() &&
John McCall03318c12011-11-11 03:57:31 +00002994 Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType()))
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002995 return false;
John McCall03318c12011-11-11 03:57:31 +00002996
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00002997 return true;
Douglas Gregor222cf0e2010-05-15 00:13:29 +00002998}
2999
Adrian Prantl9fc8faf2018-05-09 01:00:01 +00003000/// Try to perform the initialization of a potentially-movable value,
Richard Trieu09c163b2018-03-15 03:00:55 +00003001/// which is the operand to a return or throw statement.
3002///
3003/// This routine implements C++14 [class.copy]p32, which attempts to treat
3004/// returned lvalues as rvalues in certain cases (to prefer move construction),
3005/// then falls back to treating them as lvalues if that failed.
3006///
Malcolm Parsons321f24e2018-04-12 14:48:48 +00003007/// \param ConvertingConstructorsOnly If true, follow [class.copy]p32 and reject
3008/// resolutions that find non-constructors, such as derived-to-base conversions
3009/// or `operator T()&&` member functions. If false, do consider such
3010/// conversion sequences.
3011///
Richard Trieu09c163b2018-03-15 03:00:55 +00003012/// \param Res We will fill this in if move-initialization was possible.
3013/// If move-initialization is not possible, such that we must fall back to
3014/// treating the operand as an lvalue, we will leave Res in its original
3015/// invalid state.
3016static void TryMoveInitialization(Sema& S,
3017 const InitializedEntity &Entity,
3018 const VarDecl *NRVOCandidate,
3019 QualType ResultType,
3020 Expr *&Value,
Malcolm Parsons321f24e2018-04-12 14:48:48 +00003021 bool ConvertingConstructorsOnly,
Richard Trieu09c163b2018-03-15 03:00:55 +00003022 ExprResult &Res) {
3023 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, Value->getType(),
3024 CK_NoOp, Value, VK_XValue);
3025
3026 Expr *InitExpr = &AsRvalue;
3027
3028 InitializationKind Kind = InitializationKind::CreateCopy(
Stephen Kellyf2ceec42018-08-09 21:08:08 +00003029 Value->getBeginLoc(), Value->getBeginLoc());
Richard Trieu09c163b2018-03-15 03:00:55 +00003030
3031 InitializationSequence Seq(S, Entity, Kind, InitExpr);
3032
3033 if (!Seq)
3034 return;
3035
3036 for (const InitializationSequence::Step &Step : Seq.steps()) {
3037 if (Step.Kind != InitializationSequence::SK_ConstructorInitialization &&
3038 Step.Kind != InitializationSequence::SK_UserConversion)
3039 continue;
3040
3041 FunctionDecl *FD = Step.Function.Function;
Malcolm Parsons321f24e2018-04-12 14:48:48 +00003042 if (ConvertingConstructorsOnly) {
3043 if (isa<CXXConstructorDecl>(FD)) {
3044 // C++14 [class.copy]p32:
3045 // [...] If the first overload resolution fails or was not performed,
3046 // or if the type of the first parameter of the selected constructor
3047 // is not an rvalue reference to the object's type (possibly
3048 // cv-qualified), overload resolution is performed again, considering
3049 // the object as an lvalue.
3050 const RValueReferenceType *RRefType =
3051 FD->getParamDecl(0)->getType()->getAs<RValueReferenceType>();
3052 if (!RRefType)
3053 break;
3054 if (!S.Context.hasSameUnqualifiedType(RRefType->getPointeeType(),
3055 NRVOCandidate->getType()))
3056 break;
3057 } else {
3058 continue;
3059 }
Richard Trieu09c163b2018-03-15 03:00:55 +00003060 } else {
Malcolm Parsons321f24e2018-04-12 14:48:48 +00003061 if (isa<CXXConstructorDecl>(FD)) {
3062 // Check that overload resolution selected a constructor taking an
3063 // rvalue reference. If it selected an lvalue reference, then we
3064 // didn't need to cast this thing to an rvalue in the first place.
3065 if (!isa<RValueReferenceType>(FD->getParamDecl(0)->getType()))
3066 break;
3067 } else if (isa<CXXMethodDecl>(FD)) {
3068 // Check that overload resolution selected a conversion operator
3069 // taking an rvalue reference.
3070 if (cast<CXXMethodDecl>(FD)->getRefQualifier() != RQ_RValue)
3071 break;
3072 } else {
3073 continue;
3074 }
Richard Trieu09c163b2018-03-15 03:00:55 +00003075 }
3076
3077 // Promote "AsRvalue" to the heap, since we now need this
3078 // expression node to persist.
3079 Value = ImplicitCastExpr::Create(S.Context, Value->getType(), CK_NoOp,
3080 Value, nullptr, VK_XValue);
3081
3082 // Complete type-checking the initialization of the return type
3083 // using the constructor we found.
3084 Res = Seq.Perform(S, Entity, Kind, Value);
3085 }
3086}
3087
Adrian Prantl9fc8faf2018-05-09 01:00:01 +00003088/// Perform the initialization of a potentially-movable value, which
Douglas Gregor626fbed2011-01-21 21:08:57 +00003089/// is the result of return value.
Douglas Gregorf282a762011-01-21 19:38:21 +00003090///
Erik Pilkingtonfc235eb2016-06-30 23:09:13 +00003091/// This routine implements C++14 [class.copy]p32, which attempts to treat
Douglas Gregorf282a762011-01-21 19:38:21 +00003092/// returned lvalues as rvalues in certain cases (to prefer move construction),
3093/// then falls back to treating them as lvalues if that failed.
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003094ExprResult
Douglas Gregor626fbed2011-01-21 21:08:57 +00003095Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
3096 const VarDecl *NRVOCandidate,
3097 QualType ResultType,
Douglas Gregor53e191ed2011-07-06 22:04:06 +00003098 Expr *Value,
3099 bool AllowNRVO) {
Erik Pilkingtonfc235eb2016-06-30 23:09:13 +00003100 // C++14 [class.copy]p32:
3101 // When the criteria for elision of a copy/move operation are met, but not for
3102 // an exception-declaration, and the object to be copied is designated by an
3103 // lvalue, or when the expression in a return statement is a (possibly
3104 // parenthesized) id-expression that names an object with automatic storage
3105 // duration declared in the body or parameter-declaration-clause of the
3106 // innermost enclosing function or lambda-expression, overload resolution to
3107 // select the constructor for the copy is first performed as if the object
3108 // were designated by an rvalue.
Douglas Gregorf282a762011-01-21 19:38:21 +00003109 ExprResult Res = ExprError();
Erik Pilkingtonfc235eb2016-06-30 23:09:13 +00003110
Richard Trieu09c163b2018-03-15 03:00:55 +00003111 if (AllowNRVO) {
Malcolm Parsons321f24e2018-04-12 14:48:48 +00003112 bool AffectedByCWG1579 = false;
3113
Richard Trieu09c163b2018-03-15 03:00:55 +00003114 if (!NRVOCandidate) {
3115 NRVOCandidate = getCopyElisionCandidate(ResultType, Value, CES_Default);
Malcolm Parsons321f24e2018-04-12 14:48:48 +00003116 if (NRVOCandidate &&
3117 !getDiagnostics().isIgnored(diag::warn_return_std_move_in_cxx11,
3118 Value->getExprLoc())) {
3119 const VarDecl *NRVOCandidateInCXX11 =
3120 getCopyElisionCandidate(ResultType, Value, CES_FormerDefault);
3121 AffectedByCWG1579 = (!NRVOCandidateInCXX11);
3122 }
Richard Trieu09c163b2018-03-15 03:00:55 +00003123 }
Erik Pilkingtonfc235eb2016-06-30 23:09:13 +00003124
Richard Trieu09c163b2018-03-15 03:00:55 +00003125 if (NRVOCandidate) {
3126 TryMoveInitialization(*this, Entity, NRVOCandidate, ResultType, Value,
Malcolm Parsons321f24e2018-04-12 14:48:48 +00003127 true, Res);
3128 }
3129
3130 if (!Res.isInvalid() && AffectedByCWG1579) {
3131 QualType QT = NRVOCandidate->getType();
3132 if (QT.getNonReferenceType()
3133 .getUnqualifiedType()
3134 .isTriviallyCopyableType(Context)) {
3135 // Adding 'std::move' around a trivially copyable variable is probably
3136 // pointless. Don't suggest it.
3137 } else {
3138 // Common cases for this are returning unique_ptr<Derived> from a
3139 // function of return type unique_ptr<Base>, or returning T from a
3140 // function of return type Expected<T>. This is totally fine in a
3141 // post-CWG1579 world, but was not fine before.
3142 assert(!ResultType.isNull());
3143 SmallString<32> Str;
3144 Str += "std::move(";
3145 Str += NRVOCandidate->getDeclName().getAsString();
3146 Str += ")";
3147 Diag(Value->getExprLoc(), diag::warn_return_std_move_in_cxx11)
3148 << Value->getSourceRange()
3149 << NRVOCandidate->getDeclName() << ResultType << QT;
3150 Diag(Value->getExprLoc(), diag::note_add_std_move_in_cxx11)
3151 << FixItHint::CreateReplacement(Value->getSourceRange(), Str);
3152 }
3153 } else if (Res.isInvalid() &&
3154 !getDiagnostics().isIgnored(diag::warn_return_std_move,
3155 Value->getExprLoc())) {
3156 const VarDecl *FakeNRVOCandidate =
3157 getCopyElisionCandidate(QualType(), Value, CES_AsIfByStdMove);
3158 if (FakeNRVOCandidate) {
3159 QualType QT = FakeNRVOCandidate->getType();
3160 if (QT->isLValueReferenceType()) {
3161 // Adding 'std::move' around an lvalue reference variable's name is
3162 // dangerous. Don't suggest it.
3163 } else if (QT.getNonReferenceType()
3164 .getUnqualifiedType()
3165 .isTriviallyCopyableType(Context)) {
3166 // Adding 'std::move' around a trivially copyable variable is probably
3167 // pointless. Don't suggest it.
3168 } else {
3169 ExprResult FakeRes = ExprError();
3170 Expr *FakeValue = Value;
3171 TryMoveInitialization(*this, Entity, FakeNRVOCandidate, ResultType,
3172 FakeValue, false, FakeRes);
3173 if (!FakeRes.isInvalid()) {
3174 bool IsThrow =
3175 (Entity.getKind() == InitializedEntity::EK_Exception);
3176 SmallString<32> Str;
3177 Str += "std::move(";
3178 Str += FakeNRVOCandidate->getDeclName().getAsString();
3179 Str += ")";
3180 Diag(Value->getExprLoc(), diag::warn_return_std_move)
3181 << Value->getSourceRange()
3182 << FakeNRVOCandidate->getDeclName() << IsThrow;
3183 Diag(Value->getExprLoc(), diag::note_add_std_move)
3184 << FixItHint::CreateReplacement(Value->getSourceRange(), Str);
3185 }
3186 }
3187 }
Douglas Gregorf282a762011-01-21 19:38:21 +00003188 }
3189 }
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003190
Douglas Gregorf282a762011-01-21 19:38:21 +00003191 // Either we didn't meet the criteria for treating an lvalue as an rvalue,
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003192 // above, or overload resolution failed. Either way, we need to try
Douglas Gregorf282a762011-01-21 19:38:21 +00003193 // (again) now with the return value expression as written.
3194 if (Res.isInvalid())
Douglas Gregor626fbed2011-01-21 21:08:57 +00003195 Res = PerformCopyInitialization(Entity, SourceLocation(), Value);
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003196
Douglas Gregorf282a762011-01-21 19:38:21 +00003197 return Res;
3198}
3199
Adrian Prantl9fc8faf2018-05-09 01:00:01 +00003200/// Determine whether the declared return type of the specified function
Richard Smith4db51c22013-09-25 05:02:54 +00003201/// contains 'auto'.
3202static bool hasDeducedReturnType(FunctionDecl *FD) {
3203 const FunctionProtoType *FPT =
3204 FD->getTypeSourceInfo()->getType()->castAs<FunctionProtoType>();
Alp Toker314cc812014-01-25 16:55:45 +00003205 return FPT->getReturnType()->isUndeducedType();
Richard Smith4db51c22013-09-25 05:02:54 +00003206}
3207
Eli Friedman34b49062012-01-26 03:00:14 +00003208/// ActOnCapScopeReturnStmt - Utility routine to type-check return statements
3209/// for capturing scopes.
Steve Naroffc540d662008-09-03 18:15:37 +00003210///
John McCalldadc5752010-08-24 06:29:42 +00003211StmtResult
Eli Friedman34b49062012-01-26 03:00:14 +00003212Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
3213 // If this is the first return we've seen, infer the return type.
Richard Smith9155be12013-05-12 03:09:35 +00003214 // [expr.prim.lambda]p4 in C++11; block literals follow the same rules.
Eli Friedman34b49062012-01-26 03:00:14 +00003215 CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction());
Jordan Rosed39e5f12012-07-02 21:19:23 +00003216 QualType FnRetType = CurCap->ReturnType;
Richard Smith4db51c22013-09-25 05:02:54 +00003217 LambdaScopeInfo *CurLambda = dyn_cast<LambdaScopeInfo>(CurCap);
Richard Smithb130fe72016-06-23 19:16:49 +00003218 bool HasDeducedReturnType =
3219 CurLambda && hasDeducedReturnType(CurLambda->CallOperator);
Manuel Klimek2fdbea22013-08-22 12:12:24 +00003220
Faisal Valid143a0c2017-04-01 21:30:49 +00003221 if (ExprEvalContexts.back().Context ==
3222 ExpressionEvaluationContext::DiscardedStatement &&
Richard Smithb130fe72016-06-23 19:16:49 +00003223 (HasDeducedReturnType || CurCap->HasImplicitReturnType)) {
3224 if (RetValExp) {
3225 ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
3226 if (ER.isInvalid())
3227 return StmtError();
3228 RetValExp = ER.get();
3229 }
Bruno Ricci023b1d12018-10-30 14:40:49 +00003230 return ReturnStmt::Create(Context, ReturnLoc, RetValExp,
3231 /* NRVOCandidate=*/nullptr);
Richard Smithb130fe72016-06-23 19:16:49 +00003232 }
3233
3234 if (HasDeducedReturnType) {
Richard Smith4db51c22013-09-25 05:02:54 +00003235 // In C++1y, the return type may involve 'auto'.
3236 // FIXME: Blocks might have a return type of 'auto' explicitly specified.
3237 FunctionDecl *FD = CurLambda->CallOperator;
3238 if (CurCap->ReturnType.isNull())
Alp Toker314cc812014-01-25 16:55:45 +00003239 CurCap->ReturnType = FD->getReturnType();
Richard Smith4db51c22013-09-25 05:02:54 +00003240
3241 AutoType *AT = CurCap->ReturnType->getContainedAutoType();
3242 assert(AT && "lost auto type from lambda return type");
3243 if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) {
3244 FD->setInvalidDecl();
3245 return StmtError();
3246 }
Alp Toker314cc812014-01-25 16:55:45 +00003247 CurCap->ReturnType = FnRetType = FD->getReturnType();
Richard Smith4db51c22013-09-25 05:02:54 +00003248 } else if (CurCap->HasImplicitReturnType) {
3249 // For blocks/lambdas with implicit return types, we check each return
3250 // statement individually, and deduce the common return type when the block
3251 // or lambda is completed.
3252 // FIXME: Fold this into the 'auto' codepath above.
Douglas Gregor940a5502012-02-09 18:40:39 +00003253 if (RetValExp && !isa<InitListExpr>(RetValExp)) {
John Wiegley01296292011-04-08 18:41:53 +00003254 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp);
3255 if (Result.isInvalid())
3256 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003257 RetValExp = Result.get();
Douglas Gregor0aa91e02011-06-05 05:04:23 +00003258
Richard Smith5a0e50c2014-12-19 22:10:51 +00003259 // DR1048: even prior to C++14, we should use the 'auto' deduction rules
3260 // when deducing a return type for a lambda-expression (or by extension
3261 // for a block). These rules differ from the stated C++11 rules only in
3262 // that they remove top-level cv-qualifiers.
Richard Smith4db51c22013-09-25 05:02:54 +00003263 if (!CurContext->isDependentContext())
Richard Smith5a0e50c2014-12-19 22:10:51 +00003264 FnRetType = RetValExp->getType().getUnqualifiedType();
Richard Smith4db51c22013-09-25 05:02:54 +00003265 else
Jordan Rosed39e5f12012-07-02 21:19:23 +00003266 FnRetType = CurCap->ReturnType = Context.DependentTy;
Chad Rosier02a84392012-08-10 17:56:09 +00003267 } else {
Douglas Gregor940a5502012-02-09 18:40:39 +00003268 if (RetValExp) {
3269 // C++11 [expr.lambda.prim]p4 bans inferring the result from an
3270 // initializer list, because it is not an expression (even
3271 // though we represent it as one). We still deduce 'void'.
3272 Diag(ReturnLoc, diag::err_lambda_return_init_list)
3273 << RetValExp->getSourceRange();
3274 }
Manuel Klimek2fdbea22013-08-22 12:12:24 +00003275
Jordan Rosed39e5f12012-07-02 21:19:23 +00003276 FnRetType = Context.VoidTy;
Fariborz Jahanian5c12ca82011-12-03 23:53:56 +00003277 }
Jordan Rosed39e5f12012-07-02 21:19:23 +00003278
3279 // Although we'll properly infer the type of the block once it's completed,
3280 // make sure we provide a return type now for better error recovery.
3281 if (CurCap->ReturnType.isNull())
3282 CurCap->ReturnType = FnRetType;
Steve Naroffc540d662008-09-03 18:15:37 +00003283 }
Eli Friedman34b49062012-01-26 03:00:14 +00003284 assert(!FnRetType.isNull());
Sebastian Redl573feed2009-01-18 13:19:59 +00003285
Douglas Gregorcf11eb72012-02-15 16:20:15 +00003286 if (BlockScopeInfo *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) {
Eli Friedman34b49062012-01-26 03:00:14 +00003287 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) {
3288 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr);
3289 return StmtError();
3290 }
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00003291 } else if (CapturedRegionScopeInfo *CurRegion =
3292 dyn_cast<CapturedRegionScopeInfo>(CurCap)) {
3293 Diag(ReturnLoc, diag::err_return_in_captured_stmt) << CurRegion->getRegionName();
3294 return StmtError();
Douglas Gregorcf11eb72012-02-15 16:20:15 +00003295 } else {
Richard Smith4db51c22013-09-25 05:02:54 +00003296 assert(CurLambda && "unknown kind of captured scope");
3297 if (CurLambda->CallOperator->getType()->getAs<FunctionType>()
3298 ->getNoReturnAttr()) {
Douglas Gregorcf11eb72012-02-15 16:20:15 +00003299 Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr);
3300 return StmtError();
3301 }
3302 }
Mike Stump56ed2ea2009-04-29 21:40:37 +00003303
Steve Naroffc540d662008-09-03 18:15:37 +00003304 // Otherwise, verify that this result type matches the previous one. We are
3305 // pickier with blocks than for normal functions because we don't have GCC
3306 // compatibility to worry about here.
Craig Topperc3ec1492014-05-26 06:22:03 +00003307 const VarDecl *NRVOCandidate = nullptr;
Manuel Klimek2fdbea22013-08-22 12:12:24 +00003308 if (FnRetType->isDependentType()) {
John McCall5500ef22011-08-17 22:09:46 +00003309 // Delay processing for now. TODO: there are lots of dependent
3310 // types we can conclusively prove aren't void.
3311 } else if (FnRetType->isVoidType()) {
Sebastian Redl74b173e2012-02-22 17:38:04 +00003312 if (RetValExp && !isa<InitListExpr>(RetValExp) &&
David Blaikiebbafb8a2012-03-11 07:00:24 +00003313 !(getLangOpts().CPlusPlus &&
John McCall5500ef22011-08-17 22:09:46 +00003314 (RetValExp->isTypeDependent() ||
3315 RetValExp->getType()->isVoidType()))) {
Fariborz Jahanian3ba24ba2012-03-21 16:45:13 +00003316 if (!getLangOpts().CPlusPlus &&
3317 RetValExp->getType()->isVoidType())
Fariborz Jahanian0740ed92012-03-21 20:28:39 +00003318 Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2;
Fariborz Jahanian3ba24ba2012-03-21 16:45:13 +00003319 else {
3320 Diag(ReturnLoc, diag::err_return_block_has_expr);
Craig Topperc3ec1492014-05-26 06:22:03 +00003321 RetValExp = nullptr;
Fariborz Jahanian3ba24ba2012-03-21 16:45:13 +00003322 }
Steve Naroffc540d662008-09-03 18:15:37 +00003323 }
Douglas Gregor6fd1b182010-05-15 06:01:05 +00003324 } else if (!RetValExp) {
John McCall5500ef22011-08-17 22:09:46 +00003325 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr));
3326 } else if (!RetValExp->isTypeDependent()) {
3327 // we have a non-void block with an expression, continue checking
Sebastian Redl573feed2009-01-18 13:19:59 +00003328
John McCall5500ef22011-08-17 22:09:46 +00003329 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
3330 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
3331 // function return.
Sebastian Redl573feed2009-01-18 13:19:59 +00003332
John McCall5500ef22011-08-17 22:09:46 +00003333 // In C++ the return statement is handled via a copy initialization.
3334 // the C version of which boils down to CheckSingleAssignmentConstraints.
Richard Trieu09c163b2018-03-15 03:00:55 +00003335 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
John McCall5500ef22011-08-17 22:09:46 +00003336 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
3337 FnRetType,
Craig Topperc3ec1492014-05-26 06:22:03 +00003338 NRVOCandidate != nullptr);
John McCall5500ef22011-08-17 22:09:46 +00003339 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
3340 FnRetType, RetValExp);
3341 if (Res.isInvalid()) {
3342 // FIXME: Cleanup temporaries here, anyway?
3343 return StmtError();
Anders Carlsson6f923f82010-01-29 18:30:20 +00003344 }
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003345 RetValExp = Res.get();
Ted Kremenekef9e7f82014-01-22 06:10:28 +00003346 CheckReturnValExpr(RetValExp, FnRetType, ReturnLoc);
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00003347 } else {
Richard Trieu09c163b2018-03-15 03:00:55 +00003348 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
Steve Naroffc540d662008-09-03 18:15:37 +00003349 }
Sebastian Redl573feed2009-01-18 13:19:59 +00003350
John McCall75f92b52011-08-17 21:34:14 +00003351 if (RetValExp) {
Richard Smith945f8d32013-01-14 22:39:08 +00003352 ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
3353 if (ER.isInvalid())
3354 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003355 RetValExp = ER.get();
John McCall75f92b52011-08-17 21:34:14 +00003356 }
Bruno Ricci023b1d12018-10-30 14:40:49 +00003357 auto *Result =
3358 ReturnStmt::Create(Context, ReturnLoc, RetValExp, NRVOCandidate);
John McCall75f92b52011-08-17 21:34:14 +00003359
Jordan Rosed39e5f12012-07-02 21:19:23 +00003360 // If we need to check for the named return value optimization,
3361 // or if we need to infer the return type,
3362 // save the return statement in our scope for later processing.
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00003363 if (CurCap->HasImplicitReturnType || NRVOCandidate)
Douglas Gregor6fd1b182010-05-15 06:01:05 +00003364 FunctionScopes.back()->Returns.push_back(Result);
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003365
Richard Smith9f690bd2015-10-27 06:02:45 +00003366 if (FunctionScopes.back()->FirstReturnLoc.isInvalid())
3367 FunctionScopes.back()->FirstReturnLoc = ReturnLoc;
3368
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003369 return Result;
Steve Naroffc540d662008-09-03 18:15:37 +00003370}
Manuel Klimek2fdbea22013-08-22 12:12:24 +00003371
Nico Weber72889432014-09-06 01:25:55 +00003372namespace {
Adrian Prantl9fc8faf2018-05-09 01:00:01 +00003373/// Marks all typedefs in all local classes in a type referenced.
Nico Weber72889432014-09-06 01:25:55 +00003374///
3375/// In a function like
3376/// auto f() {
3377/// struct S { typedef int a; };
3378/// return S();
3379/// }
3380///
3381/// the local type escapes and could be referenced in some TUs but not in
3382/// others. Pretend that all local typedefs are always referenced, to not warn
3383/// on this. This isn't necessary if f has internal linkage, or the typedef
3384/// is private.
3385class LocalTypedefNameReferencer
3386 : public RecursiveASTVisitor<LocalTypedefNameReferencer> {
3387public:
3388 LocalTypedefNameReferencer(Sema &S) : S(S) {}
3389 bool VisitRecordType(const RecordType *RT);
3390private:
3391 Sema &S;
3392};
3393bool LocalTypedefNameReferencer::VisitRecordType(const RecordType *RT) {
3394 auto *R = dyn_cast<CXXRecordDecl>(RT->getDecl());
3395 if (!R || !R->isLocalClass() || !R->isLocalClass()->isExternallyVisible() ||
3396 R->isDependentType())
3397 return true;
3398 for (auto *TmpD : R->decls())
3399 if (auto *T = dyn_cast<TypedefNameDecl>(TmpD))
3400 if (T->getAccess() != AS_private || R->hasFriends())
3401 S.MarkAnyDeclReferenced(T->getLocation(), T, /*OdrUse=*/false);
3402 return true;
3403}
Alexander Kornienkoab9db512015-06-22 23:07:51 +00003404}
Nico Weber72889432014-09-06 01:25:55 +00003405
Saleem Abdulrasool374b5aa2014-10-16 22:42:53 +00003406TypeLoc Sema::getReturnTypeLoc(FunctionDecl *FD) const {
Saleem Abdulrasoole8aab742014-10-17 17:20:33 +00003407 TypeLoc TL = FD->getTypeSourceInfo()->getTypeLoc().IgnoreParens();
Saleem Abdulrasool374b5aa2014-10-16 22:42:53 +00003408 while (auto ATL = TL.getAs<AttributedTypeLoc>())
3409 TL = ATL.getModifiedLoc().IgnoreParens();
Saleem Abdulrasoole8aab742014-10-17 17:20:33 +00003410 return TL.castAs<FunctionProtoTypeLoc>().getReturnLoc();
Saleem Abdulrasool374b5aa2014-10-16 22:42:53 +00003411}
3412
Richard Smith2a7d4812013-05-04 07:00:32 +00003413/// Deduce the return type for a function from a returned expression, per
3414/// C++1y [dcl.spec.auto]p6.
3415bool Sema::DeduceFunctionTypeFromReturnExpr(FunctionDecl *FD,
3416 SourceLocation ReturnLoc,
3417 Expr *&RetExpr,
3418 AutoType *AT) {
Richard Smith50e291e2018-01-02 23:52:42 +00003419 // If this is the conversion function for a lambda, we choose to deduce it
3420 // type from the corresponding call operator, not from the synthesized return
3421 // statement within it. See Sema::DeduceReturnType.
3422 if (isLambdaConversionOperator(FD))
3423 return false;
3424
Saleem Abdulrasool374b5aa2014-10-16 22:42:53 +00003425 TypeLoc OrigResultType = getReturnTypeLoc(FD);
Richard Smith2a7d4812013-05-04 07:00:32 +00003426 QualType Deduced;
Manuel Klimek2fdbea22013-08-22 12:12:24 +00003427
Richard Smithc58f38f2013-08-14 20:16:31 +00003428 if (RetExpr && isa<InitListExpr>(RetExpr)) {
3429 // If the deduction is for a return statement and the initializer is
3430 // a braced-init-list, the program is ill-formed.
Richard Smith4db51c22013-09-25 05:02:54 +00003431 Diag(RetExpr->getExprLoc(),
3432 getCurLambda() ? diag::err_lambda_return_init_list
3433 : diag::err_auto_fn_return_init_list)
3434 << RetExpr->getSourceRange();
Richard Smithc58f38f2013-08-14 20:16:31 +00003435 return true;
3436 }
3437
3438 if (FD->isDependentContext()) {
3439 // C++1y [dcl.spec.auto]p12:
3440 // Return type deduction [...] occurs when the definition is
3441 // instantiated even if the function body contains a return
3442 // statement with a non-type-dependent operand.
3443 assert(AT->isDeduced() && "should have deduced to dependent type");
3444 return false;
Fangrui Song6907ce22018-07-30 19:24:48 +00003445 }
Richard Smith2a7d4812013-05-04 07:00:32 +00003446
Douglas Gregor6032d5b2015-10-01 19:52:44 +00003447 if (RetExpr) {
Richard Smith2a7d4812013-05-04 07:00:32 +00003448 // Otherwise, [...] deduce a value for U using the rules of template
3449 // argument deduction.
3450 DeduceAutoResult DAR = DeduceAutoType(OrigResultType, RetExpr, Deduced);
3451
3452 if (DAR == DAR_Failed && !FD->isInvalidDecl())
3453 Diag(RetExpr->getExprLoc(), diag::err_auto_fn_deduction_failure)
3454 << OrigResultType.getType() << RetExpr->getType();
3455
3456 if (DAR != DAR_Succeeded)
3457 return true;
Nico Weber72889432014-09-06 01:25:55 +00003458
3459 // If a local type is part of the returned type, mark its fields as
3460 // referenced.
3461 LocalTypedefNameReferencer Referencer(*this);
3462 Referencer.TraverseType(RetExpr->getType());
Richard Smith2a7d4812013-05-04 07:00:32 +00003463 } else {
3464 // In the case of a return with no operand, the initializer is considered
3465 // to be void().
3466 //
3467 // Deduction here can only succeed if the return type is exactly 'cv auto'
3468 // or 'decltype(auto)', so just check for that case directly.
3469 if (!OrigResultType.getType()->getAs<AutoType>()) {
3470 Diag(ReturnLoc, diag::err_auto_fn_return_void_but_not_auto)
3471 << OrigResultType.getType();
3472 return true;
3473 }
3474 // We always deduce U = void in this case.
3475 Deduced = SubstAutoType(OrigResultType.getType(), Context.VoidTy);
3476 if (Deduced.isNull())
3477 return true;
3478 }
3479
3480 // If a function with a declared return type that contains a placeholder type
3481 // has multiple return statements, the return type is deduced for each return
3482 // statement. [...] if the type deduced is not the same in each deduction,
3483 // the program is ill-formed.
Argyrios Kyrtzidisb4030df2016-01-30 01:51:20 +00003484 QualType DeducedT = AT->getDeducedType();
3485 if (!DeducedT.isNull() && !FD->isInvalidDecl()) {
Richard Smith2a7d4812013-05-04 07:00:32 +00003486 AutoType *NewAT = Deduced->getContainedAutoType();
Manman Renb4e8a1b2016-02-04 20:05:40 +00003487 // It is possible that NewAT->getDeducedType() is null. When that happens,
3488 // we should not crash, instead we ignore this deduction.
3489 if (NewAT->getDeducedType().isNull())
3490 return false;
3491
Douglas Gregora602a152015-10-01 20:20:47 +00003492 CanQualType OldDeducedType = Context.getCanonicalFunctionResultType(
Argyrios Kyrtzidisb4030df2016-01-30 01:51:20 +00003493 DeducedT);
Douglas Gregora602a152015-10-01 20:20:47 +00003494 CanQualType NewDeducedType = Context.getCanonicalFunctionResultType(
3495 NewAT->getDeducedType());
3496 if (!FD->isDependentContext() && OldDeducedType != NewDeducedType) {
Richard Smith4db51c22013-09-25 05:02:54 +00003497 const LambdaScopeInfo *LambdaSI = getCurLambda();
3498 if (LambdaSI && LambdaSI->HasImplicitReturnType) {
3499 Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible)
Argyrios Kyrtzidisb4030df2016-01-30 01:51:20 +00003500 << NewAT->getDeducedType() << DeducedT
Richard Smith4db51c22013-09-25 05:02:54 +00003501 << true /*IsLambda*/;
3502 } else {
3503 Diag(ReturnLoc, diag::err_auto_fn_different_deductions)
3504 << (AT->isDecltypeAuto() ? 1 : 0)
Argyrios Kyrtzidisb4030df2016-01-30 01:51:20 +00003505 << NewAT->getDeducedType() << DeducedT;
Richard Smith4db51c22013-09-25 05:02:54 +00003506 }
Richard Smith2a7d4812013-05-04 07:00:32 +00003507 return true;
3508 }
3509 } else if (!FD->isInvalidDecl()) {
3510 // Update all declarations of the function to have the deduced return type.
3511 Context.adjustDeducedFunctionResultType(FD, Deduced);
3512 }
3513
3514 return false;
3515}
3516
John McCalldadc5752010-08-24 06:29:42 +00003517StmtResult
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00003518Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
3519 Scope *CurScope) {
3520 StmtResult R = BuildReturnStmt(ReturnLoc, RetValExp);
Faisal Valid143a0c2017-04-01 21:30:49 +00003521 if (R.isInvalid() || ExprEvalContexts.back().Context ==
3522 ExpressionEvaluationContext::DiscardedStatement)
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00003523 return R;
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00003524
Taiju Tsuiki3be68e12018-06-19 05:35:30 +00003525 if (VarDecl *VD =
3526 const_cast<VarDecl*>(cast<ReturnStmt>(R.get())->getNRVOCandidate())) {
3527 CurScope->addNRVOCandidate(VD);
3528 } else {
3529 CurScope->setNoNRVO();
3530 }
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00003531
Nico Weberd64657f2015-03-09 02:47:59 +00003532 CheckJumpOutOfSEHFinally(*this, ReturnLoc, *CurScope->getFnParent());
3533
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00003534 return R;
3535}
3536
3537StmtResult Sema::BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
Douglas Gregor4385d8b2011-05-20 15:32:55 +00003538 // Check for unexpanded parameter packs.
3539 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp))
3540 return StmtError();
Manuel Klimek2fdbea22013-08-22 12:12:24 +00003541
Eli Friedman34b49062012-01-26 03:00:14 +00003542 if (isa<CapturingScopeInfo>(getCurFunction()))
3543 return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp);
Manuel Klimek2fdbea22013-08-22 12:12:24 +00003544
Chris Lattner79413952008-12-04 23:50:19 +00003545 QualType FnRetType;
Eli Friedman410fc7a2012-03-30 01:13:43 +00003546 QualType RelatedRetType;
Craig Topperc3ec1492014-05-26 06:22:03 +00003547 const AttrVec *Attrs = nullptr;
Ted Kremenekef9e7f82014-01-22 06:10:28 +00003548 bool isObjCMethod = false;
3549
Mike Stumpd00bc1a2009-04-29 00:43:21 +00003550 if (const FunctionDecl *FD = getCurFunctionDecl()) {
Alp Toker314cc812014-01-25 16:55:45 +00003551 FnRetType = FD->getReturnType();
Ted Kremenekef9e7f82014-01-22 06:10:28 +00003552 if (FD->hasAttrs())
3553 Attrs = &FD->getAttrs();
Richard Smith10876ef2013-01-17 01:30:42 +00003554 if (FD->isNoReturn())
Chris Lattner6e127a62009-05-31 19:32:13 +00003555 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr)
Eli Friedmande958782012-01-05 00:49:17 +00003556 << FD->getDeclName();
Richard Smith9bb192e2016-11-29 01:35:17 +00003557 if (FD->isMain() && RetValExp)
3558 if (isa<CXXBoolLiteralExpr>(RetValExp))
3559 Diag(ReturnLoc, diag::warn_main_returns_bool_literal)
3560 << RetValExp->getSourceRange();
Douglas Gregor33823722011-06-11 01:09:30 +00003561 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) {
Alp Toker314cc812014-01-25 16:55:45 +00003562 FnRetType = MD->getReturnType();
Ted Kremenekef9e7f82014-01-22 06:10:28 +00003563 isObjCMethod = true;
3564 if (MD->hasAttrs())
3565 Attrs = &MD->getAttrs();
Douglas Gregor33823722011-06-11 01:09:30 +00003566 if (MD->hasRelatedResultType() && MD->getClassInterface()) {
3567 // In the implementation of a method with a related return type, the
Chad Rosier02a84392012-08-10 17:56:09 +00003568 // type used to type-check the validity of return statements within the
Douglas Gregor33823722011-06-11 01:09:30 +00003569 // method body is a pointer to the type of the class being implemented.
Eli Friedman410fc7a2012-03-30 01:13:43 +00003570 RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface());
3571 RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType);
Douglas Gregor33823722011-06-11 01:09:30 +00003572 }
3573 } else // If we don't have a function/method context, bail.
Steve Narofff3833d72009-03-03 00:45:38 +00003574 return StmtError();
Mike Stump11289f42009-09-09 15:08:12 +00003575
Richard Smithb130fe72016-06-23 19:16:49 +00003576 // C++1z: discarded return statements are not considered when deducing a
3577 // return type.
Faisal Valid143a0c2017-04-01 21:30:49 +00003578 if (ExprEvalContexts.back().Context ==
3579 ExpressionEvaluationContext::DiscardedStatement &&
Richard Smithb130fe72016-06-23 19:16:49 +00003580 FnRetType->getContainedAutoType()) {
3581 if (RetValExp) {
3582 ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
3583 if (ER.isInvalid())
3584 return StmtError();
3585 RetValExp = ER.get();
3586 }
Bruno Ricci023b1d12018-10-30 14:40:49 +00003587 return ReturnStmt::Create(Context, ReturnLoc, RetValExp,
3588 /* NRVOCandidate=*/nullptr);
Richard Smithb130fe72016-06-23 19:16:49 +00003589 }
3590
Richard Smith2a7d4812013-05-04 07:00:32 +00003591 // FIXME: Add a flag to the ScopeInfo to indicate whether we're performing
3592 // deduction.
Aaron Ballmandd69ef32014-08-19 15:55:55 +00003593 if (getLangOpts().CPlusPlus14) {
Richard Smith2a7d4812013-05-04 07:00:32 +00003594 if (AutoType *AT = FnRetType->getContainedAutoType()) {
3595 FunctionDecl *FD = cast<FunctionDecl>(CurContext);
Richard Smithc58f38f2013-08-14 20:16:31 +00003596 if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) {
Richard Smith2a7d4812013-05-04 07:00:32 +00003597 FD->setInvalidDecl();
3598 return StmtError();
3599 } else {
Alp Toker314cc812014-01-25 16:55:45 +00003600 FnRetType = FD->getReturnType();
Richard Smith2a7d4812013-05-04 07:00:32 +00003601 }
3602 }
3603 }
3604
Richard Smithc58f38f2013-08-14 20:16:31 +00003605 bool HasDependentReturnType = FnRetType->isDependentType();
3606
Craig Topperc3ec1492014-05-26 06:22:03 +00003607 ReturnStmt *Result = nullptr;
Chris Lattner9bad62c2008-01-04 18:04:52 +00003608 if (FnRetType->isVoidType()) {
Nick Lewycky1be750a2011-06-01 07:44:31 +00003609 if (RetValExp) {
Sebastian Redleef474c2012-02-22 10:50:08 +00003610 if (isa<InitListExpr>(RetValExp)) {
3611 // We simply never allow init lists as the return value of void
3612 // functions. This is compatible because this was never allowed before,
3613 // so there's no legacy code to deal with.
3614 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3615 int FunctionKind = 0;
3616 if (isa<ObjCMethodDecl>(CurDecl))
3617 FunctionKind = 1;
3618 else if (isa<CXXConstructorDecl>(CurDecl))
3619 FunctionKind = 2;
3620 else if (isa<CXXDestructorDecl>(CurDecl))
3621 FunctionKind = 3;
3622
3623 Diag(ReturnLoc, diag::err_return_init_list)
3624 << CurDecl->getDeclName() << FunctionKind
3625 << RetValExp->getSourceRange();
3626
3627 // Drop the expression.
Craig Topperc3ec1492014-05-26 06:22:03 +00003628 RetValExp = nullptr;
Sebastian Redleef474c2012-02-22 10:50:08 +00003629 } else if (!RetValExp->isTypeDependent()) {
Nick Lewycky1be750a2011-06-01 07:44:31 +00003630 // C99 6.8.6.4p1 (ext_ since GCC warns)
3631 unsigned D = diag::ext_return_has_expr;
Fariborz Jahaniana7598482013-12-03 17:10:08 +00003632 if (RetValExp->getType()->isVoidType()) {
3633 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3634 if (isa<CXXConstructorDecl>(CurDecl) ||
3635 isa<CXXDestructorDecl>(CurDecl))
3636 D = diag::err_ctor_dtor_returns_void;
3637 else
3638 D = diag::ext_return_has_void_expr;
3639 }
Nick Lewycky1be750a2011-06-01 07:44:31 +00003640 else {
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003641 ExprResult Result = RetValExp;
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003642 Result = IgnoredValueConversions(Result.get());
Nick Lewycky1be750a2011-06-01 07:44:31 +00003643 if (Result.isInvalid())
3644 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003645 RetValExp = Result.get();
Nick Lewycky1be750a2011-06-01 07:44:31 +00003646 RetValExp = ImpCastExprToType(RetValExp,
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003647 Context.VoidTy, CK_ToVoid).get();
Nick Lewycky1be750a2011-06-01 07:44:31 +00003648 }
Fariborz Jahaniana7598482013-12-03 17:10:08 +00003649 // return of void in constructor/destructor is illegal in C++.
3650 if (D == diag::err_ctor_dtor_returns_void) {
3651 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
3652 Diag(ReturnLoc, D)
3653 << CurDecl->getDeclName() << isa<CXXDestructorDecl>(CurDecl)
3654 << RetValExp->getSourceRange();
3655 }
Nick Lewycky1be750a2011-06-01 07:44:31 +00003656 // return (some void expression); is legal in C++.
Fariborz Jahaniana7598482013-12-03 17:10:08 +00003657 else if (D != diag::ext_return_has_void_expr ||
Craig Topper8f7f3ea2015-11-17 05:40:05 +00003658 !getLangOpts().CPlusPlus) {
Nick Lewycky1be750a2011-06-01 07:44:31 +00003659 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
Chandler Carruth1406d6c2011-06-30 08:56:22 +00003660
3661 int FunctionKind = 0;
3662 if (isa<ObjCMethodDecl>(CurDecl))
3663 FunctionKind = 1;
3664 else if (isa<CXXConstructorDecl>(CurDecl))
3665 FunctionKind = 2;
3666 else if (isa<CXXDestructorDecl>(CurDecl))
3667 FunctionKind = 3;
3668
Nick Lewycky1be750a2011-06-01 07:44:31 +00003669 Diag(ReturnLoc, D)
Chandler Carruth1406d6c2011-06-30 08:56:22 +00003670 << CurDecl->getDeclName() << FunctionKind
Nick Lewycky1be750a2011-06-01 07:44:31 +00003671 << RetValExp->getSourceRange();
3672 }
Chris Lattner0cb00d62008-12-18 02:03:48 +00003673 }
Mike Stump11289f42009-09-09 15:08:12 +00003674
Sebastian Redleef474c2012-02-22 10:50:08 +00003675 if (RetValExp) {
Richard Smith945f8d32013-01-14 22:39:08 +00003676 ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
3677 if (ER.isInvalid())
3678 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003679 RetValExp = ER.get();
Sebastian Redleef474c2012-02-22 10:50:08 +00003680 }
Steve Naroff6f49f5d2007-05-29 14:23:36 +00003681 }
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003682
Bruno Ricci023b1d12018-10-30 14:40:49 +00003683 Result = ReturnStmt::Create(Context, ReturnLoc, RetValExp,
3684 /* NRVOCandidate=*/nullptr);
Richard Smith2a7d4812013-05-04 07:00:32 +00003685 } else if (!RetValExp && !HasDependentReturnType) {
David Majnemer2887ad32014-12-13 08:12:56 +00003686 FunctionDecl *FD = getCurFunctionDecl();
Chris Lattner4bd8dd82008-11-19 08:23:25 +00003687
David Majnemer2887ad32014-12-13 08:12:56 +00003688 unsigned DiagID;
3689 if (getLangOpts().CPlusPlus11 && FD && FD->isConstexpr()) {
3690 // C++11 [stmt.return]p2
3691 DiagID = diag::err_constexpr_return_missing_expr;
3692 FD->setInvalidDecl();
3693 } else if (getLangOpts().C99) {
3694 // C99 6.8.6.4p1 (ext_ since GCC warns)
3695 DiagID = diag::ext_return_missing_expr;
3696 } else {
3697 // C90 6.6.6.4p4
3698 DiagID = diag::warn_return_missing_expr;
3699 }
3700
3701 if (FD)
Chris Lattnere3d20d92008-11-23 21:45:46 +00003702 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/;
Chris Lattner4bd8dd82008-11-19 08:23:25 +00003703 else
Chris Lattnere3d20d92008-11-23 21:45:46 +00003704 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/;
David Majnemer2887ad32014-12-13 08:12:56 +00003705
Bruno Ricci023b1d12018-10-30 14:40:49 +00003706 Result = ReturnStmt::Create(Context, ReturnLoc, /* RetExpr=*/nullptr,
3707 /* NRVOCandidate=*/nullptr);
Douglas Gregor6fd1b182010-05-15 06:01:05 +00003708 } else {
Richard Smith2a7d4812013-05-04 07:00:32 +00003709 assert(RetValExp || HasDependentReturnType);
Craig Topperc3ec1492014-05-26 06:22:03 +00003710 const VarDecl *NRVOCandidate = nullptr;
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00003711
3712 QualType RetType = RelatedRetType.isNull() ? FnRetType : RelatedRetType;
3713
3714 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
3715 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
3716 // function return.
3717
3718 // In C++ the return statement is handled via a copy initialization,
3719 // the C version of which boils down to CheckSingleAssignmentConstraints.
3720 if (RetValExp)
Richard Trieu09c163b2018-03-15 03:00:55 +00003721 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict);
Richard Smith2a7d4812013-05-04 07:00:32 +00003722 if (!HasDependentReturnType && !RetValExp->isTypeDependent()) {
Douglas Gregor6fd1b182010-05-15 06:01:05 +00003723 // we have a non-void function with an expression, continue checking
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003724 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
John McCall5ec7e7d2013-03-19 07:04:25 +00003725 RetType,
Craig Topperc3ec1492014-05-26 06:22:03 +00003726 NRVOCandidate != nullptr);
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003727 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
John McCall5ec7e7d2013-03-19 07:04:25 +00003728 RetType, RetValExp);
Douglas Gregor6fd1b182010-05-15 06:01:05 +00003729 if (Res.isInvalid()) {
John McCall5ec7e7d2013-03-19 07:04:25 +00003730 // FIXME: Clean up temporaries here anyway?
Douglas Gregor6fd1b182010-05-15 06:01:05 +00003731 return StmtError();
3732 }
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003733 RetValExp = Res.getAs<Expr>();
John McCall5ec7e7d2013-03-19 07:04:25 +00003734
3735 // If we have a related result type, we need to implicitly
3736 // convert back to the formal result type. We can't pretend to
3737 // initialize the result again --- we might end double-retaining
Fariborz Jahanianb248ca52013-07-11 16:48:06 +00003738 // --- so instead we initialize a notional temporary.
John McCall5ec7e7d2013-03-19 07:04:25 +00003739 if (!RelatedRetType.isNull()) {
Fariborz Jahanianb248ca52013-07-11 16:48:06 +00003740 Entity = InitializedEntity::InitializeRelatedResult(getCurMethodDecl(),
3741 FnRetType);
John McCall5ec7e7d2013-03-19 07:04:25 +00003742 Res = PerformCopyInitialization(Entity, ReturnLoc, RetValExp);
3743 if (Res.isInvalid()) {
3744 // FIXME: Clean up temporaries here anyway?
3745 return StmtError();
3746 }
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003747 RetValExp = Res.getAs<Expr>();
John McCall5ec7e7d2013-03-19 07:04:25 +00003748 }
3749
Artyom Skrobov9f213442014-01-24 11:10:39 +00003750 CheckReturnValExpr(RetValExp, FnRetType, ReturnLoc, isObjCMethod, Attrs,
3751 getCurFunctionDecl());
Douglas Gregorffe14e32009-11-14 01:20:54 +00003752 }
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003753
John McCallacf0ee52010-10-08 02:01:28 +00003754 if (RetValExp) {
Richard Smith945f8d32013-01-14 22:39:08 +00003755 ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
3756 if (ER.isInvalid())
3757 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003758 RetValExp = ER.get();
John McCallacf0ee52010-10-08 02:01:28 +00003759 }
Bruno Ricci023b1d12018-10-30 14:40:49 +00003760 Result = ReturnStmt::Create(Context, ReturnLoc, RetValExp, NRVOCandidate);
Douglas Gregor4619e432008-12-05 23:32:09 +00003761 }
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003762
3763 // If we need to check for the named return value optimization, save the
Douglas Gregor6fd1b182010-05-15 06:01:05 +00003764 // return statement in our scope for later processing.
Nick Lewyckyd78f92f2014-05-03 00:41:18 +00003765 if (Result->getNRVOCandidate())
Douglas Gregor6fd1b182010-05-15 06:01:05 +00003766 FunctionScopes.back()->Returns.push_back(Result);
Chad Rosiercc6a9082012-06-20 18:51:04 +00003767
Richard Smith9f690bd2015-10-27 06:02:45 +00003768 if (FunctionScopes.back()->FirstReturnLoc.isInvalid())
3769 FunctionScopes.back()->FirstReturnLoc = ReturnLoc;
3770
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003771 return Result;
Chris Lattneraf8d5812006-11-10 05:07:45 +00003772}
3773
John McCalldadc5752010-08-24 06:29:42 +00003774StmtResult
Sebastian Redl481bf3f2009-01-18 17:43:11 +00003775Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
John McCall48871652010-08-21 09:40:31 +00003776 SourceLocation RParen, Decl *Parm,
John McCallb268a282010-08-23 23:25:46 +00003777 Stmt *Body) {
John McCall48871652010-08-21 09:40:31 +00003778 VarDecl *Var = cast_or_null<VarDecl>(Parm);
Douglas Gregorf3564192010-04-26 17:32:49 +00003779 if (Var && Var->isInvalidDecl())
3780 return StmtError();
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003781
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003782 return new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body);
Fariborz Jahanian9e63b982007-11-01 23:59:59 +00003783}
3784
John McCalldadc5752010-08-24 06:29:42 +00003785StmtResult
John McCallb268a282010-08-23 23:25:46 +00003786Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) {
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003787 return new (Context) ObjCAtFinallyStmt(AtLoc, Body);
Fariborz Jahanian71234d82007-11-02 00:18:53 +00003788}
Fariborz Jahanianf859ef22007-11-02 15:39:31 +00003789
John McCalldadc5752010-08-24 06:29:42 +00003790StmtResult
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003791Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try,
John McCallb268a282010-08-23 23:25:46 +00003792 MultiStmtArg CatchStmts, Stmt *Finally) {
David Blaikiebbafb8a2012-03-11 07:00:24 +00003793 if (!getLangOpts().ObjCExceptions)
Anders Carlssonce8dd3a2011-02-19 23:53:54 +00003794 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try";
3795
Reid Kleckner87a31802018-03-12 21:43:02 +00003796 setFunctionHasBranchProtectedScope();
Douglas Gregor96c79492010-04-23 22:50:49 +00003797 unsigned NumCatchStmts = CatchStmts.size();
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003798 return ObjCAtTryStmt::Create(Context, AtLoc, Try, CatchStmts.data(),
3799 NumCatchStmts, Finally);
Fariborz Jahanianf859ef22007-11-02 15:39:31 +00003800}
3801
John McCall0bd3e402012-05-08 21:41:25 +00003802StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw) {
Douglas Gregor2900c162010-04-22 21:44:01 +00003803 if (Throw) {
John Wiegley01296292011-04-08 18:41:53 +00003804 ExprResult Result = DefaultLvalueConversion(Throw);
3805 if (Result.isInvalid())
3806 return StmtError();
John McCall15317a22010-12-15 04:42:30 +00003807
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003808 Result = ActOnFinishFullExpr(Result.get());
Richard Smith945f8d32013-01-14 22:39:08 +00003809 if (Result.isInvalid())
3810 return StmtError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003811 Throw = Result.get();
Richard Smith945f8d32013-01-14 22:39:08 +00003812
Douglas Gregor2900c162010-04-22 21:44:01 +00003813 QualType ThrowType = Throw->getType();
3814 // Make sure the expression type is an ObjC pointer or "void *".
3815 if (!ThrowType->isDependentType() &&
3816 !ThrowType->isObjCObjectPointerType()) {
3817 const PointerType *PT = ThrowType->getAs<PointerType>();
3818 if (!PT || !PT->getPointeeType()->isVoidType())
Richard Smithf8812672016-12-02 22:38:31 +00003819 return StmtError(Diag(AtLoc, diag::err_objc_throw_expects_object)
Douglas Gregor2900c162010-04-22 21:44:01 +00003820 << Throw->getType() << Throw->getSourceRange());
3821 }
3822 }
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003823
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003824 return new (Context) ObjCAtThrowStmt(AtLoc, Throw);
Douglas Gregor2900c162010-04-22 21:44:01 +00003825}
3826
John McCalldadc5752010-08-24 06:29:42 +00003827StmtResult
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003828Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw,
Douglas Gregor2900c162010-04-22 21:44:01 +00003829 Scope *CurScope) {
David Blaikiebbafb8a2012-03-11 07:00:24 +00003830 if (!getLangOpts().ObjCExceptions)
Anders Carlssonce8dd3a2011-02-19 23:53:54 +00003831 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw";
3832
John McCallb268a282010-08-23 23:25:46 +00003833 if (!Throw) {
Nico Weber9af63b22015-03-09 02:34:29 +00003834 // @throw without an expression designates a rethrow (which must occur
Steve Naroff5ee2c022009-02-11 20:05:44 +00003835 // in the context of an @catch clause).
3836 Scope *AtCatchParent = CurScope;
3837 while (AtCatchParent && !AtCatchParent->isAtCatchScope())
3838 AtCatchParent = AtCatchParent->getParent();
3839 if (!AtCatchParent)
Richard Smithf8812672016-12-02 22:38:31 +00003840 return StmtError(Diag(AtLoc, diag::err_rethrow_used_outside_catch));
NAKAMURA Takumif9cbcc42011-01-27 07:10:08 +00003841 }
John McCallb268a282010-08-23 23:25:46 +00003842 return BuildObjCAtThrowStmt(AtLoc, Throw);
Fariborz Jahanianadfbbc32007-11-07 02:00:49 +00003843}
Fariborz Jahanianf859ef22007-11-02 15:39:31 +00003844
John McCalld9bb7432011-07-27 21:50:02 +00003845ExprResult
3846Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) {
3847 ExprResult result = DefaultLvalueConversion(operand);
3848 if (result.isInvalid())
3849 return ExprError();
Nikola Smiljanic01a75982014-05-29 10:55:11 +00003850 operand = result.get();
John McCalld9bb7432011-07-27 21:50:02 +00003851
3852 // Make sure the expression type is an ObjC pointer or "void *".
3853 QualType type = operand->getType();
3854 if (!type->isDependentType() &&
3855 !type->isObjCObjectPointerType()) {
3856 const PointerType *pointerType = type->getAs<PointerType>();
Jordan Rose5790d522014-08-12 16:20:36 +00003857 if (!pointerType || !pointerType->getPointeeType()->isVoidType()) {
3858 if (getLangOpts().CPlusPlus) {
3859 if (RequireCompleteType(atLoc, type,
3860 diag::err_incomplete_receiver_type))
Richard Smithf8812672016-12-02 22:38:31 +00003861 return Diag(atLoc, diag::err_objc_synchronized_expects_object)
Jordan Rose5790d522014-08-12 16:20:36 +00003862 << type << operand->getSourceRange();
3863
3864 ExprResult result = PerformContextuallyConvertToObjCPointer(operand);
Richard Smithe15a3702016-10-06 23:12:58 +00003865 if (result.isInvalid())
3866 return ExprError();
Jordan Rose5790d522014-08-12 16:20:36 +00003867 if (!result.isUsable())
Richard Smithf8812672016-12-02 22:38:31 +00003868 return Diag(atLoc, diag::err_objc_synchronized_expects_object)
Jordan Rose5790d522014-08-12 16:20:36 +00003869 << type << operand->getSourceRange();
3870
3871 operand = result.get();
3872 } else {
Richard Smithf8812672016-12-02 22:38:31 +00003873 return Diag(atLoc, diag::err_objc_synchronized_expects_object)
Jordan Rose5790d522014-08-12 16:20:36 +00003874 << type << operand->getSourceRange();
3875 }
3876 }
John McCalld9bb7432011-07-27 21:50:02 +00003877 }
3878
3879 // The operand to @synchronized is a full-expression.
Richard Smith945f8d32013-01-14 22:39:08 +00003880 return ActOnFinishFullExpr(operand);
John McCalld9bb7432011-07-27 21:50:02 +00003881}
3882
John McCalldadc5752010-08-24 06:29:42 +00003883StmtResult
John McCallb268a282010-08-23 23:25:46 +00003884Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr,
3885 Stmt *SyncBody) {
John McCalld9bb7432011-07-27 21:50:02 +00003886 // We can't jump into or indirect-jump out of a @synchronized block.
Reid Kleckner87a31802018-03-12 21:43:02 +00003887 setFunctionHasBranchProtectedScope();
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003888 return new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody);
Fariborz Jahanian48085b82008-01-29 19:14:59 +00003889}
Sebastian Redl54c04d42008-12-22 19:15:10 +00003890
3891/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block
3892/// and creates a proper catch handler from them.
John McCalldadc5752010-08-24 06:29:42 +00003893StmtResult
John McCall48871652010-08-21 09:40:31 +00003894Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl,
John McCallb268a282010-08-23 23:25:46 +00003895 Stmt *HandlerBlock) {
Sebastian Redl54c04d42008-12-22 19:15:10 +00003896 // There's nothing to test that ActOnExceptionDecl didn't already test.
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003897 return new (Context)
3898 CXXCatchStmt(CatchLoc, cast_or_null<VarDecl>(ExDecl), HandlerBlock);
Sebastian Redl54c04d42008-12-22 19:15:10 +00003899}
Sebastian Redl9b244a82008-12-22 21:35:02 +00003900
John McCall31168b02011-06-15 23:02:42 +00003901StmtResult
3902Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) {
Reid Kleckner87a31802018-03-12 21:43:02 +00003903 setFunctionHasBranchProtectedScope();
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00003904 return new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body);
John McCall31168b02011-06-15 23:02:42 +00003905}
3906
Benjamin Kramer439ee9d2015-05-01 13:59:53 +00003907namespace {
Aaron Ballman8aee642902015-04-08 00:05:29 +00003908class CatchHandlerType {
3909 QualType QT;
3910 unsigned IsPointer : 1;
Dan Gohman28ade552010-07-26 21:25:24 +00003911
Aaron Ballman8aee642902015-04-08 00:05:29 +00003912 // This is a special constructor to be used only with DenseMapInfo's
3913 // getEmptyKey() and getTombstoneKey() functions.
3914 friend struct llvm::DenseMapInfo<CatchHandlerType>;
3915 enum Unique { ForDenseMap };
3916 CatchHandlerType(QualType QT, Unique) : QT(QT), IsPointer(false) {}
3917
Sebastian Redl63c4da02009-07-29 17:15:45 +00003918public:
Aaron Ballman8aee642902015-04-08 00:05:29 +00003919 /// Used when creating a CatchHandlerType from a handler type; will determine
Eric Christopher2c4555a2015-06-19 01:52:53 +00003920 /// whether the type is a pointer or reference and will strip off the top
Aaron Ballman8aee642902015-04-08 00:05:29 +00003921 /// level pointer and cv-qualifiers.
3922 CatchHandlerType(QualType Q) : QT(Q), IsPointer(false) {
3923 if (QT->isPointerType())
3924 IsPointer = true;
Sebastian Redl63c4da02009-07-29 17:15:45 +00003925
Aaron Ballman8aee642902015-04-08 00:05:29 +00003926 if (IsPointer || QT->isReferenceType())
3927 QT = QT->getPointeeType();
3928 QT = QT.getUnqualifiedType();
3929 }
3930
3931 /// Used when creating a CatchHandlerType from a base class type; pretends the
3932 /// type passed in had the pointer qualifier, does not need to get an
3933 /// unqualified type.
3934 CatchHandlerType(QualType QT, bool IsPointer)
3935 : QT(QT), IsPointer(IsPointer) {}
3936
3937 QualType underlying() const { return QT; }
3938 bool isPointer() const { return IsPointer; }
3939
3940 friend bool operator==(const CatchHandlerType &LHS,
3941 const CatchHandlerType &RHS) {
3942 // If the pointer qualification does not match, we can return early.
3943 if (LHS.IsPointer != RHS.IsPointer)
Sebastian Redl63c4da02009-07-29 17:15:45 +00003944 return false;
Aaron Ballman8aee642902015-04-08 00:05:29 +00003945 // Otherwise, check the underlying type without cv-qualifiers.
3946 return LHS.QT == RHS.QT;
Sebastian Redl63c4da02009-07-29 17:15:45 +00003947 }
3948};
Benjamin Kramer439ee9d2015-05-01 13:59:53 +00003949} // namespace
Sebastian Redl63c4da02009-07-29 17:15:45 +00003950
Aaron Ballman8aee642902015-04-08 00:05:29 +00003951namespace llvm {
3952template <> struct DenseMapInfo<CatchHandlerType> {
3953 static CatchHandlerType getEmptyKey() {
3954 return CatchHandlerType(DenseMapInfo<QualType>::getEmptyKey(),
3955 CatchHandlerType::ForDenseMap);
3956 }
3957
3958 static CatchHandlerType getTombstoneKey() {
3959 return CatchHandlerType(DenseMapInfo<QualType>::getTombstoneKey(),
3960 CatchHandlerType::ForDenseMap);
3961 }
3962
3963 static unsigned getHashValue(const CatchHandlerType &Base) {
3964 return DenseMapInfo<QualType>::getHashValue(Base.underlying());
3965 }
3966
3967 static bool isEqual(const CatchHandlerType &LHS,
3968 const CatchHandlerType &RHS) {
3969 return LHS == RHS;
3970 }
3971};
Alexander Kornienkoab9db512015-06-22 23:07:51 +00003972}
Aaron Ballman8aee642902015-04-08 00:05:29 +00003973
3974namespace {
3975class CatchTypePublicBases {
3976 ASTContext &Ctx;
3977 const llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> &TypesToCheck;
3978 const bool CheckAgainstPointer;
3979
3980 CXXCatchStmt *FoundHandler;
3981 CanQualType FoundHandlerType;
3982
3983public:
3984 CatchTypePublicBases(
3985 ASTContext &Ctx,
3986 const llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> &T, bool C)
3987 : Ctx(Ctx), TypesToCheck(T), CheckAgainstPointer(C),
3988 FoundHandler(nullptr) {}
3989
3990 CXXCatchStmt *getFoundHandler() const { return FoundHandler; }
3991 CanQualType getFoundHandlerType() const { return FoundHandlerType; }
3992
Benjamin Kramer6e4f6e12015-07-25 15:07:25 +00003993 bool operator()(const CXXBaseSpecifier *S, CXXBasePath &) {
Aaron Ballman8aee642902015-04-08 00:05:29 +00003994 if (S->getAccessSpecifier() == AccessSpecifier::AS_public) {
Benjamin Kramer6e4f6e12015-07-25 15:07:25 +00003995 CatchHandlerType Check(S->getType(), CheckAgainstPointer);
Benjamin Kramer536ffdf2016-02-13 15:49:17 +00003996 const auto &M = TypesToCheck;
Aaron Ballman8aee642902015-04-08 00:05:29 +00003997 auto I = M.find(Check);
3998 if (I != M.end()) {
Benjamin Kramer6e4f6e12015-07-25 15:07:25 +00003999 FoundHandler = I->second;
4000 FoundHandlerType = Ctx.getCanonicalType(S->getType());
Aaron Ballman8aee642902015-04-08 00:05:29 +00004001 return true;
4002 }
4003 }
4004 return false;
4005 }
4006};
Alexander Kornienkoab9db512015-06-22 23:07:51 +00004007}
Dan Gohman28ade552010-07-26 21:25:24 +00004008
Sebastian Redl9b244a82008-12-22 21:35:02 +00004009/// ActOnCXXTryBlock - Takes a try compound-statement and a number of
4010/// handlers and creates a try statement from them.
Robert Wilhelmcafda822013-08-22 09:20:03 +00004011StmtResult Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock,
4012 ArrayRef<Stmt *> Handlers) {
Anders Carlssond99dbcc2011-02-23 03:46:46 +00004013 // Don't report an error if 'try' is used in system headers.
David Blaikiebbafb8a2012-03-11 07:00:24 +00004014 if (!getLangOpts().CXXExceptions &&
Alexey Bataev1ab34572018-05-02 16:52:07 +00004015 !getSourceManager().isInSystemHeader(TryLoc) &&
4016 (!getLangOpts().OpenMPIsDevice ||
4017 !getLangOpts().OpenMPHostCXXExceptions ||
4018 isInOpenMPTargetExecutionDirective() ||
4019 isInOpenMPDeclareTargetContext()))
Aaron Ballman8aee642902015-04-08 00:05:29 +00004020 Diag(TryLoc, diag::err_exceptions_disabled) << "try";
Anders Carlsson68b36af2011-02-19 19:26:44 +00004021
Justin Lebar2a8db342016-09-28 22:45:54 +00004022 // Exceptions aren't allowed in CUDA device code.
4023 if (getLangOpts().CUDA)
Justin Lebar179bdce2016-10-13 18:45:08 +00004024 CUDADiagIfDeviceCode(TryLoc, diag::err_cuda_device_exceptions)
4025 << "try" << CurrentCUDATarget();
Justin Lebar2a8db342016-09-28 22:45:54 +00004026
Alexander Musmana8e9d2e2014-06-03 10:16:47 +00004027 if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
4028 Diag(TryLoc, diag::err_omp_simd_region_cannot_use_stmt) << "try";
4029
Reid Klecknerdeeddec2015-02-05 18:56:03 +00004030 sema::FunctionScopeInfo *FSI = getCurFunction();
4031
Reid Klecknere7175912015-02-02 22:15:31 +00004032 // C++ try is incompatible with SEH __try.
Reid Klecknerdeeddec2015-02-05 18:56:03 +00004033 if (!getLangOpts().Borland && FSI->FirstSEHTryLoc.isValid()) {
Reid Klecknere7175912015-02-02 22:15:31 +00004034 Diag(TryLoc, diag::err_mixing_cxx_try_seh_try);
Reid Klecknerdeeddec2015-02-05 18:56:03 +00004035 Diag(FSI->FirstSEHTryLoc, diag::note_conflicting_try_here) << "'__try'";
Reid Klecknere7175912015-02-02 22:15:31 +00004036 }
4037
Robert Wilhelmcafda822013-08-22 09:20:03 +00004038 const unsigned NumHandlers = Handlers.size();
Aaron Ballman8aee642902015-04-08 00:05:29 +00004039 assert(!Handlers.empty() &&
Sebastian Redl9b244a82008-12-22 21:35:02 +00004040 "The parser shouldn't call this if there are no handlers.");
Sebastian Redl9b244a82008-12-22 21:35:02 +00004041
Aaron Ballman8aee642902015-04-08 00:05:29 +00004042 llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> HandledTypes;
Mike Stump11289f42009-09-09 15:08:12 +00004043 for (unsigned i = 0; i < NumHandlers; ++i) {
Aaron Ballman8aee642902015-04-08 00:05:29 +00004044 CXXCatchStmt *H = cast<CXXCatchStmt>(Handlers[i]);
Mike Stump11289f42009-09-09 15:08:12 +00004045
Aaron Ballman8aee642902015-04-08 00:05:29 +00004046 // Diagnose when the handler is a catch-all handler, but it isn't the last
4047 // handler for the try block. [except.handle]p5. Also, skip exception
4048 // declarations that are invalid, since we can't usefully report on them.
4049 if (!H->getExceptionDecl()) {
4050 if (i < NumHandlers - 1)
Stephen Kellyf2ceec42018-08-09 21:08:08 +00004051 return StmtError(Diag(H->getBeginLoc(), diag::err_early_catch_all));
Sebastian Redl63c4da02009-07-29 17:15:45 +00004052 continue;
Aaron Ballman8aee642902015-04-08 00:05:29 +00004053 } else if (H->getExceptionDecl()->isInvalidDecl())
4054 continue;
4055
4056 // Walk the type hierarchy to diagnose when this type has already been
4057 // handled (duplication), or cannot be handled (derivation inversion). We
4058 // ignore top-level cv-qualifiers, per [except.handle]p3
Aaron Ballmanaa301de2015-04-08 00:13:33 +00004059 CatchHandlerType HandlerCHT =
4060 (QualType)Context.getCanonicalType(H->getCaughtType());
Aaron Ballman8aee642902015-04-08 00:05:29 +00004061
4062 // We can ignore whether the type is a reference or a pointer; we need the
4063 // underlying declaration type in order to get at the underlying record
4064 // decl, if there is one.
4065 QualType Underlying = HandlerCHT.underlying();
4066 if (auto *RD = Underlying->getAsCXXRecordDecl()) {
4067 if (!RD->hasDefinition())
4068 continue;
4069 // Check that none of the public, unambiguous base classes are in the
4070 // map ([except.handle]p1). Give the base classes the same pointer
4071 // qualification as the original type we are basing off of. This allows
4072 // comparison against the handler type using the same top-level pointer
4073 // as the original type.
4074 CXXBasePaths Paths;
4075 Paths.setOrigin(RD);
4076 CatchTypePublicBases CTPB(Context, HandledTypes, HandlerCHT.isPointer());
Benjamin Kramer6e4f6e12015-07-25 15:07:25 +00004077 if (RD->lookupInBases(CTPB, Paths)) {
Aaron Ballman8aee642902015-04-08 00:05:29 +00004078 const CXXCatchStmt *Problem = CTPB.getFoundHandler();
4079 if (!Paths.isAmbiguous(CTPB.getFoundHandlerType())) {
4080 Diag(H->getExceptionDecl()->getTypeSpecStartLoc(),
4081 diag::warn_exception_caught_by_earlier_handler)
4082 << H->getCaughtType();
4083 Diag(Problem->getExceptionDecl()->getTypeSpecStartLoc(),
4084 diag::note_previous_exception_handler)
4085 << Problem->getCaughtType();
4086 }
4087 }
Sebastian Redl63c4da02009-07-29 17:15:45 +00004088 }
Mike Stump11289f42009-09-09 15:08:12 +00004089
Aaron Ballman8aee642902015-04-08 00:05:29 +00004090 // Add the type the list of ones we have handled; diagnose if we've already
4091 // handled it.
4092 auto R = HandledTypes.insert(std::make_pair(H->getCaughtType(), H));
4093 if (!R.second) {
4094 const CXXCatchStmt *Problem = R.first->second;
4095 Diag(H->getExceptionDecl()->getTypeSpecStartLoc(),
4096 diag::warn_exception_caught_by_earlier_handler)
4097 << H->getCaughtType();
4098 Diag(Problem->getExceptionDecl()->getTypeSpecStartLoc(),
4099 diag::note_previous_exception_handler)
4100 << Problem->getCaughtType();
Sebastian Redl63c4da02009-07-29 17:15:45 +00004101 }
4102 }
Mike Stump11289f42009-09-09 15:08:12 +00004103
Reid Klecknerdeeddec2015-02-05 18:56:03 +00004104 FSI->setHasCXXTry(TryLoc);
John McCalla95172b2010-08-01 00:26:45 +00004105
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00004106 return CXXTryStmt::Create(Context, TryLoc, TryBlock, Handlers);
Sebastian Redl9b244a82008-12-22 21:35:02 +00004107}
John Wiegley1c0675e2011-04-28 01:08:34 +00004108
Reid Klecknere7175912015-02-02 22:15:31 +00004109StmtResult Sema::ActOnSEHTryBlock(bool IsCXXTry, SourceLocation TryLoc,
4110 Stmt *TryBlock, Stmt *Handler) {
John Wiegley1c0675e2011-04-28 01:08:34 +00004111 assert(TryBlock && Handler);
4112
Reid Klecknerdeeddec2015-02-05 18:56:03 +00004113 sema::FunctionScopeInfo *FSI = getCurFunction();
4114
Reid Klecknere7175912015-02-02 22:15:31 +00004115 // SEH __try is incompatible with C++ try. Borland appears to support this,
4116 // however.
Reid Klecknerdeeddec2015-02-05 18:56:03 +00004117 if (!getLangOpts().Borland) {
4118 if (FSI->FirstCXXTryLoc.isValid()) {
4119 Diag(TryLoc, diag::err_mixing_cxx_try_seh_try);
4120 Diag(FSI->FirstCXXTryLoc, diag::note_conflicting_try_here) << "'try'";
4121 }
Reid Klecknere7175912015-02-02 22:15:31 +00004122 }
John Wiegley1c0675e2011-04-28 01:08:34 +00004123
Reid Klecknerdeeddec2015-02-05 18:56:03 +00004124 FSI->setHasSEHTry(TryLoc);
4125
4126 // Reject __try in Obj-C methods, blocks, and captured decls, since we don't
4127 // track if they use SEH.
4128 DeclContext *DC = CurContext;
4129 while (DC && !DC->isFunctionOrMethod())
4130 DC = DC->getParent();
4131 FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(DC);
4132 if (FD)
4133 FD->setUsesSEHTry(true);
4134 else
4135 Diag(TryLoc, diag::err_seh_try_outside_functions);
Reid Klecknere7175912015-02-02 22:15:31 +00004136
Reid Kleckner8819a402015-07-10 00:16:25 +00004137 // Reject __try on unsupported targets.
4138 if (!Context.getTargetInfo().isSEHTrySupported())
4139 Diag(TryLoc, diag::err_seh_try_unsupported);
4140
Reid Klecknere7175912015-02-02 22:15:31 +00004141 return SEHTryStmt::Create(Context, IsCXXTry, TryLoc, TryBlock, Handler);
John Wiegley1c0675e2011-04-28 01:08:34 +00004142}
4143
4144StmtResult
4145Sema::ActOnSEHExceptBlock(SourceLocation Loc,
4146 Expr *FilterExpr,
4147 Stmt *Block) {
4148 assert(FilterExpr && Block);
4149
4150 if(!FilterExpr->getType()->isIntegerType()) {
Francois Pichetfbf7e172011-06-02 00:47:27 +00004151 return StmtError(Diag(FilterExpr->getExprLoc(),
4152 diag::err_filter_expression_integral)
4153 << FilterExpr->getType());
John Wiegley1c0675e2011-04-28 01:08:34 +00004154 }
4155
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00004156 return SEHExceptStmt::Create(Context,Loc,FilterExpr,Block);
John Wiegley1c0675e2011-04-28 01:08:34 +00004157}
4158
Nico Weberd64657f2015-03-09 02:47:59 +00004159void Sema::ActOnStartSEHFinallyBlock() {
4160 CurrentSEHFinally.push_back(CurScope);
4161}
4162
Nico Weberce903292015-03-09 03:17:15 +00004163void Sema::ActOnAbortSEHFinallyBlock() {
4164 CurrentSEHFinally.pop_back();
4165}
4166
Nico Weberd64657f2015-03-09 02:47:59 +00004167StmtResult Sema::ActOnFinishSEHFinallyBlock(SourceLocation Loc, Stmt *Block) {
John Wiegley1c0675e2011-04-28 01:08:34 +00004168 assert(Block);
Nico Weberd64657f2015-03-09 02:47:59 +00004169 CurrentSEHFinally.pop_back();
4170 return SEHFinallyStmt::Create(Context, Loc, Block);
John Wiegley1c0675e2011-04-28 01:08:34 +00004171}
Douglas Gregordeb4a2be2011-10-25 01:33:02 +00004172
Nico Weberc7d05962014-07-06 22:32:59 +00004173StmtResult
4174Sema::ActOnSEHLeaveStmt(SourceLocation Loc, Scope *CurScope) {
Nico Webereb61d4d2014-07-06 22:53:19 +00004175 Scope *SEHTryParent = CurScope;
4176 while (SEHTryParent && !SEHTryParent->isSEHTryScope())
4177 SEHTryParent = SEHTryParent->getParent();
4178 if (!SEHTryParent)
4179 return StmtError(Diag(Loc, diag::err_ms___leave_not_in___try));
Nico Weberd64657f2015-03-09 02:47:59 +00004180 CheckJumpOutOfSEHFinally(*this, Loc, *SEHTryParent);
Nico Webereb61d4d2014-07-06 22:53:19 +00004181
Nico Weber9b982072014-07-07 00:12:30 +00004182 return new (Context) SEHLeaveStmt(Loc);
Nico Weberc7d05962014-07-06 22:32:59 +00004183}
4184
Douglas Gregordeb4a2be2011-10-25 01:33:02 +00004185StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc,
4186 bool IsIfExists,
4187 NestedNameSpecifierLoc QualifierLoc,
4188 DeclarationNameInfo NameInfo,
4189 Stmt *Nested)
4190{
4191 return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists,
Chad Rosier02a84392012-08-10 17:56:09 +00004192 QualifierLoc, NameInfo,
Douglas Gregordeb4a2be2011-10-25 01:33:02 +00004193 cast<CompoundStmt>(Nested));
4194}
4195
4196
Chad Rosier02a84392012-08-10 17:56:09 +00004197StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc,
Douglas Gregordeb4a2be2011-10-25 01:33:02 +00004198 bool IsIfExists,
Chad Rosier02a84392012-08-10 17:56:09 +00004199 CXXScopeSpec &SS,
Douglas Gregordeb4a2be2011-10-25 01:33:02 +00004200 UnqualifiedId &Name,
4201 Stmt *Nested) {
Chad Rosier02a84392012-08-10 17:56:09 +00004202 return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists,
Douglas Gregordeb4a2be2011-10-25 01:33:02 +00004203 SS.getWithLocInContext(Context),
4204 GetNameFromUnqualifiedId(Name),
4205 Nested);
4206}
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004207
4208RecordDecl*
Ben Langmuir37943a72013-05-03 19:00:33 +00004209Sema::CreateCapturedStmtRecordDecl(CapturedDecl *&CD, SourceLocation Loc,
4210 unsigned NumParams) {
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004211 DeclContext *DC = CurContext;
4212 while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext()))
4213 DC = DC->getParent();
4214
Craig Topperc3ec1492014-05-26 06:22:03 +00004215 RecordDecl *RD = nullptr;
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004216 if (getLangOpts().CPlusPlus)
Craig Topperc3ec1492014-05-26 06:22:03 +00004217 RD = CXXRecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc,
4218 /*Id=*/nullptr);
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004219 else
Craig Topperc3ec1492014-05-26 06:22:03 +00004220 RD = RecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc, /*Id=*/nullptr);
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004221
Alexey Bataev330de032014-10-29 12:21:55 +00004222 RD->setCapturedRecord();
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004223 DC->addDecl(RD);
4224 RD->setImplicit();
4225 RD->startDefinition();
4226
Alexey Bataev9959db52014-05-06 10:08:46 +00004227 assert(NumParams > 0 && "CapturedStmt requires context parameter");
Ben Langmuir37943a72013-05-03 19:00:33 +00004228 CD = CapturedDecl::Create(Context, CurContext, NumParams);
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004229 DC->addDecl(CD);
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004230 return RD;
4231}
4232
Reid Kleckner04f9bca2018-03-07 22:48:35 +00004233static void
4234buildCapturedStmtCaptureList(SmallVectorImpl<CapturedStmt::Capture> &Captures,
4235 SmallVectorImpl<Expr *> &CaptureInits,
4236 ArrayRef<sema::Capture> Candidates) {
4237 for (const sema::Capture &Cap : Candidates) {
4238 if (Cap.isThisCapture()) {
4239 Captures.push_back(CapturedStmt::Capture(Cap.getLocation(),
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004240 CapturedStmt::VCK_This));
Reid Kleckner04f9bca2018-03-07 22:48:35 +00004241 CaptureInits.push_back(Cap.getInitExpr());
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004242 continue;
Reid Kleckner04f9bca2018-03-07 22:48:35 +00004243 } else if (Cap.isVLATypeCapture()) {
Alexey Bataev330de032014-10-29 12:21:55 +00004244 Captures.push_back(
Reid Kleckner04f9bca2018-03-07 22:48:35 +00004245 CapturedStmt::Capture(Cap.getLocation(), CapturedStmt::VCK_VLAType));
Alexey Bataev330de032014-10-29 12:21:55 +00004246 CaptureInits.push_back(nullptr);
4247 continue;
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004248 }
4249
Reid Kleckner04f9bca2018-03-07 22:48:35 +00004250 Captures.push_back(CapturedStmt::Capture(Cap.getLocation(),
4251 Cap.isReferenceCapture()
Samuel Antao4af1b7b2015-12-02 17:44:43 +00004252 ? CapturedStmt::VCK_ByRef
4253 : CapturedStmt::VCK_ByCopy,
Reid Kleckner04f9bca2018-03-07 22:48:35 +00004254 Cap.getVariable()));
4255 CaptureInits.push_back(Cap.getInitExpr());
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004256 }
4257}
4258
4259void Sema::ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
Wei Pan17fbf6e2013-05-04 03:59:06 +00004260 CapturedRegionKind Kind,
4261 unsigned NumParams) {
Alexey Bataev9959db52014-05-06 10:08:46 +00004262 CapturedDecl *CD = nullptr;
Ben Langmuir37943a72013-05-03 19:00:33 +00004263 RecordDecl *RD = CreateCapturedStmtRecordDecl(CD, Loc, NumParams);
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004264
Alexey Bataev9959db52014-05-06 10:08:46 +00004265 // Build the context parameter
4266 DeclContext *DC = CapturedDecl::castToDeclContext(CD);
4267 IdentifierInfo *ParamName = &Context.Idents.get("__context");
4268 QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD));
Alexey Bataev56223232017-06-09 13:40:18 +00004269 auto *Param =
4270 ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType,
4271 ImplicitParamDecl::CapturedContext);
Alexey Bataev9959db52014-05-06 10:08:46 +00004272 DC->addDecl(Param);
4273
4274 CD->setContextParam(0, Param);
4275
4276 // Enter the capturing scope for this captured region.
4277 PushCapturedRegionScope(CurScope, CD, RD, Kind);
4278
4279 if (CurScope)
4280 PushDeclContext(CurScope, CD);
4281 else
4282 CurContext = CD;
4283
Faisal Valid143a0c2017-04-01 21:30:49 +00004284 PushExpressionEvaluationContext(
4285 ExpressionEvaluationContext::PotentiallyEvaluated);
Alexey Bataev9959db52014-05-06 10:08:46 +00004286}
4287
4288void Sema::ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
4289 CapturedRegionKind Kind,
4290 ArrayRef<CapturedParamNameType> Params) {
4291 CapturedDecl *CD = nullptr;
4292 RecordDecl *RD = CreateCapturedStmtRecordDecl(CD, Loc, Params.size());
4293
4294 // Build the context parameter
4295 DeclContext *DC = CapturedDecl::castToDeclContext(CD);
4296 bool ContextIsFound = false;
4297 unsigned ParamNum = 0;
4298 for (ArrayRef<CapturedParamNameType>::iterator I = Params.begin(),
4299 E = Params.end();
4300 I != E; ++I, ++ParamNum) {
4301 if (I->second.isNull()) {
4302 assert(!ContextIsFound &&
4303 "null type has been found already for '__context' parameter");
4304 IdentifierInfo *ParamName = &Context.Idents.get("__context");
Alexey Bataevc0f879b2018-04-10 20:10:53 +00004305 QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD))
4306 .withConst()
4307 .withRestrict();
Alexey Bataev56223232017-06-09 13:40:18 +00004308 auto *Param =
4309 ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType,
4310 ImplicitParamDecl::CapturedContext);
Alexey Bataev9959db52014-05-06 10:08:46 +00004311 DC->addDecl(Param);
4312 CD->setContextParam(ParamNum, Param);
4313 ContextIsFound = true;
4314 } else {
4315 IdentifierInfo *ParamName = &Context.Idents.get(I->first);
Alexey Bataev56223232017-06-09 13:40:18 +00004316 auto *Param =
4317 ImplicitParamDecl::Create(Context, DC, Loc, ParamName, I->second,
4318 ImplicitParamDecl::CapturedContext);
Alexey Bataev9959db52014-05-06 10:08:46 +00004319 DC->addDecl(Param);
4320 CD->setParam(ParamNum, Param);
4321 }
4322 }
4323 assert(ContextIsFound && "no null type for '__context' parameter");
Alexey Bataev301a2d92014-05-14 10:40:54 +00004324 if (!ContextIsFound) {
4325 // Add __context implicitly if it is not specified.
4326 IdentifierInfo *ParamName = &Context.Idents.get("__context");
4327 QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD));
Alexey Bataev56223232017-06-09 13:40:18 +00004328 auto *Param =
4329 ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType,
4330 ImplicitParamDecl::CapturedContext);
Alexey Bataev301a2d92014-05-14 10:40:54 +00004331 DC->addDecl(Param);
4332 CD->setContextParam(ParamNum, Param);
4333 }
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004334 // Enter the capturing scope for this captured region.
4335 PushCapturedRegionScope(CurScope, CD, RD, Kind);
4336
4337 if (CurScope)
4338 PushDeclContext(CurScope, CD);
4339 else
4340 CurContext = CD;
4341
Faisal Valid143a0c2017-04-01 21:30:49 +00004342 PushExpressionEvaluationContext(
4343 ExpressionEvaluationContext::PotentiallyEvaluated);
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004344}
4345
Wei Pan17fbf6e2013-05-04 03:59:06 +00004346void Sema::ActOnCapturedRegionError() {
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004347 DiscardCleanupsInEvaluationContext();
4348 PopExpressionEvaluationContext();
4349
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004350 CapturedRegionScopeInfo *RSI = getCurCapturedRegion();
4351 RecordDecl *Record = RSI->TheRecordDecl;
4352 Record->setInvalidDecl();
4353
Aaron Ballman62e47c42014-03-10 13:43:55 +00004354 SmallVector<Decl*, 4> Fields(Record->fields());
Alexey Bataev9959db52014-05-06 10:08:46 +00004355 ActOnFields(/*Scope=*/nullptr, Record->getLocation(), Record, Fields,
Erich Keanec480f302018-07-12 21:09:05 +00004356 SourceLocation(), SourceLocation(), ParsedAttributesView());
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004357
Wei Pan17fbf6e2013-05-04 03:59:06 +00004358 PopDeclContext();
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004359 PopFunctionScopeInfo();
4360}
4361
4362StmtResult Sema::ActOnCapturedRegionEnd(Stmt *S) {
4363 CapturedRegionScopeInfo *RSI = getCurCapturedRegion();
4364
4365 SmallVector<CapturedStmt::Capture, 4> Captures;
4366 SmallVector<Expr *, 4> CaptureInits;
4367 buildCapturedStmtCaptureList(Captures, CaptureInits, RSI->Captures);
4368
4369 CapturedDecl *CD = RSI->TheCapturedDecl;
4370 RecordDecl *RD = RSI->TheRecordDecl;
4371
Alexey Bataev7ace49d2016-05-17 08:55:33 +00004372 CapturedStmt *Res = CapturedStmt::Create(
4373 getASTContext(), S, static_cast<CapturedRegionKind>(RSI->CapRegionKind),
4374 Captures, CaptureInits, CD, RD);
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004375
4376 CD->setBody(Res->getCapturedStmt());
4377 RD->completeDefinition();
4378
Wei Pan17fbf6e2013-05-04 03:59:06 +00004379 DiscardCleanupsInEvaluationContext();
4380 PopExpressionEvaluationContext();
4381
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004382 PopDeclContext();
4383 PopFunctionScopeInfo();
4384
Nikola Smiljanic03ff2592014-05-29 14:05:12 +00004385 return Res;
Tareq A. Siraj6dfa25a2013-04-16 19:37:38 +00004386}