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Chris Lattner566b6ce2007-08-24 02:22:53 +00001//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===//
Chris Lattneraf6f5282007-08-10 20:13:28 +00002//
3// The LLVM Compiler Infrastructure
4//
Chris Lattner0bc735f2007-12-29 19:59:25 +00005// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
Chris Lattneraf6f5282007-08-10 20:13:28 +00007//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit Aggregate Expr nodes as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
Chris Lattner883f6a72007-08-11 00:04:45 +000015#include "CodeGenModule.h"
Daniel Dunbarde7fb842008-08-11 05:00:27 +000016#include "clang/AST/ASTContext.h"
Anders Carlssonb14095a2009-04-17 00:06:03 +000017#include "clang/AST/DeclCXX.h"
Daniel Dunbarde7fb842008-08-11 05:00:27 +000018#include "clang/AST/StmtVisitor.h"
Chris Lattner883f6a72007-08-11 00:04:45 +000019#include "llvm/Constants.h"
20#include "llvm/Function.h"
Devang Patel636c3d02007-10-26 17:44:44 +000021#include "llvm/GlobalVariable.h"
Chris Lattner9c033562007-08-21 04:25:47 +000022#include "llvm/Support/Compiler.h"
Chris Lattnerf81557c2008-04-04 18:42:16 +000023#include "llvm/Intrinsics.h"
Chris Lattneraf6f5282007-08-10 20:13:28 +000024using namespace clang;
25using namespace CodeGen;
Chris Lattner883f6a72007-08-11 00:04:45 +000026
Chris Lattner9c033562007-08-21 04:25:47 +000027//===----------------------------------------------------------------------===//
28// Aggregate Expression Emitter
29//===----------------------------------------------------------------------===//
30
31namespace {
32class VISIBILITY_HIDDEN AggExprEmitter : public StmtVisitor<AggExprEmitter> {
33 CodeGenFunction &CGF;
Daniel Dunbar45d196b2008-11-01 01:53:16 +000034 CGBuilderTy &Builder;
Chris Lattner9c033562007-08-21 04:25:47 +000035 llvm::Value *DestPtr;
36 bool VolatileDest;
Mike Stump49d1cd52009-05-26 22:03:21 +000037 bool IgnoreResult;
38
Chris Lattner9c033562007-08-21 04:25:47 +000039public:
Mike Stumpff4bf3b2009-05-27 01:42:21 +000040 AggExprEmitter(CodeGenFunction &cgf, llvm::Value *destPtr, bool v,
41 bool ignore)
Chris Lattnerbfc0c1a2007-08-26 23:13:56 +000042 : CGF(cgf), Builder(CGF.Builder),
Mike Stumpff4bf3b2009-05-27 01:42:21 +000043 DestPtr(destPtr), VolatileDest(v), IgnoreResult(ignore) {
Chris Lattner9c033562007-08-21 04:25:47 +000044 }
45
Chris Lattneree755f92007-08-21 04:59:27 +000046 //===--------------------------------------------------------------------===//
47 // Utilities
48 //===--------------------------------------------------------------------===//
49
Chris Lattner9c033562007-08-21 04:25:47 +000050 /// EmitAggLoadOfLValue - Given an expression with aggregate type that
51 /// represents a value lvalue, this method emits the address of the lvalue,
52 /// then loads the result into DestPtr.
53 void EmitAggLoadOfLValue(const Expr *E);
Eli Friedman922696f2008-05-19 17:51:16 +000054
Mike Stump4ac20dd2009-05-23 20:28:01 +000055 /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
Mike Stump49d1cd52009-05-26 22:03:21 +000056 void EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore = false);
57 void EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore = false);
Mike Stump4ac20dd2009-05-23 20:28:01 +000058
Chris Lattneree755f92007-08-21 04:59:27 +000059 //===--------------------------------------------------------------------===//
60 // Visitor Methods
61 //===--------------------------------------------------------------------===//
62
Chris Lattner9c033562007-08-21 04:25:47 +000063 void VisitStmt(Stmt *S) {
Daniel Dunbar488e9932008-08-16 00:56:44 +000064 CGF.ErrorUnsupported(S, "aggregate expression");
Chris Lattner9c033562007-08-21 04:25:47 +000065 }
66 void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); }
Eli Friedman12444a22009-01-27 09:03:41 +000067 void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
Chris Lattner9c033562007-08-21 04:25:47 +000068
69 // l-values.
Seo Sanghyeon9b73b392007-12-14 02:04:12 +000070 void VisitDeclRefExpr(DeclRefExpr *DRE) { EmitAggLoadOfLValue(DRE); }
71 void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
72 void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
Seo Sanghyeonad6ebd62007-12-23 03:11:58 +000073 void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
Chris Lattnerf0a990c2009-04-21 23:00:09 +000074 void VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
75 EmitAggLoadOfLValue(E);
76 }
Seo Sanghyeon9b73b392007-12-14 02:04:12 +000077 void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
78 EmitAggLoadOfLValue(E);
79 }
Chris Lattnerf0a990c2009-04-21 23:00:09 +000080 void VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) {
81 EmitAggLoadOfLValue(E);
82 }
83 void VisitPredefinedExpr(const PredefinedExpr *E) {
84 EmitAggLoadOfLValue(E);
85 }
Douglas Gregor4c678342009-01-28 21:54:33 +000086
Chris Lattner9c033562007-08-21 04:25:47 +000087 // Operators.
Nuno Lopes7e916272009-01-15 20:14:33 +000088 void VisitCStyleCastExpr(CStyleCastExpr *E);
Anders Carlssone4707ff2008-01-14 06:28:57 +000089 void VisitImplicitCastExpr(ImplicitCastExpr *E);
Anders Carlsson148fe672007-10-31 22:04:46 +000090 void VisitCallExpr(const CallExpr *E);
Chris Lattnerb2d963f2007-08-31 22:54:14 +000091 void VisitStmtExpr(const StmtExpr *E);
Chris Lattner9c033562007-08-21 04:25:47 +000092 void VisitBinaryOperator(const BinaryOperator *BO);
Chris Lattner03d6fb92007-08-21 04:43:17 +000093 void VisitBinAssign(const BinaryOperator *E);
Eli Friedman07fa52a2008-05-20 07:56:31 +000094 void VisitBinComma(const BinaryOperator *E);
Chris Lattner9c033562007-08-21 04:25:47 +000095
Chris Lattner8fdf3282008-06-24 17:04:18 +000096 void VisitObjCMessageExpr(ObjCMessageExpr *E);
Daniel Dunbar0a04d772008-08-23 10:51:21 +000097 void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
98 EmitAggLoadOfLValue(E);
99 }
Daniel Dunbar9c3fc702008-08-27 06:57:25 +0000100 void VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E);
Fariborz Jahanian5daf5702008-11-22 18:39:36 +0000101 void VisitObjCKVCRefExpr(ObjCKVCRefExpr *E);
Chris Lattner9c033562007-08-21 04:25:47 +0000102
103 void VisitConditionalOperator(const ConditionalOperator *CO);
Devang Patel636c3d02007-10-26 17:44:44 +0000104 void VisitInitListExpr(InitListExpr *E);
Chris Lattner04421082008-04-08 04:40:51 +0000105 void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
106 Visit(DAE->getExpr());
107 }
Anders Carlssonb58d0172009-05-30 23:23:33 +0000108 void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
Anders Carlsson31ccf372009-05-03 17:47:16 +0000109 void VisitCXXConstructExpr(const CXXConstructExpr *E);
Anders Carlsson7f6ad152009-05-19 04:48:36 +0000110 void VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E);
111
Eli Friedmanb1851242008-05-27 15:51:49 +0000112 void VisitVAArgExpr(VAArgExpr *E);
Chris Lattnerf81557c2008-04-04 18:42:16 +0000113
114 void EmitInitializationToLValue(Expr *E, LValue Address);
115 void EmitNullInitializationToLValue(LValue Address, QualType T);
Chris Lattner9c033562007-08-21 04:25:47 +0000116 // case Expr::ChooseExprClass:
Lauro Ramos Venancio305762c2008-02-18 22:44:02 +0000117
Chris Lattner9c033562007-08-21 04:25:47 +0000118};
119} // end anonymous namespace.
120
Chris Lattneree755f92007-08-21 04:59:27 +0000121//===----------------------------------------------------------------------===//
122// Utilities
123//===----------------------------------------------------------------------===//
Chris Lattner9c033562007-08-21 04:25:47 +0000124
Chris Lattner883f6a72007-08-11 00:04:45 +0000125/// EmitAggLoadOfLValue - Given an expression with aggregate type that
126/// represents a value lvalue, this method emits the address of the lvalue,
127/// then loads the result into DestPtr.
Chris Lattner9c033562007-08-21 04:25:47 +0000128void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) {
129 LValue LV = CGF.EmitLValue(E);
Mike Stump4ac20dd2009-05-23 20:28:01 +0000130 EmitFinalDestCopy(E, LV);
131}
132
133/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
Mike Stump49d1cd52009-05-26 22:03:21 +0000134void AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore) {
Mike Stump4ac20dd2009-05-23 20:28:01 +0000135 assert(Src.isAggregate() && "value must be aggregate value!");
136
Chris Lattner883f6a72007-08-11 00:04:45 +0000137 // If the result is ignored, don't copy from the value.
Mike Stump9ccb1032009-05-23 22:01:27 +0000138 if (DestPtr == 0) {
Mike Stump49d1cd52009-05-26 22:03:21 +0000139 if (!Src.isVolatileQualified() || (IgnoreResult && Ignore))
Mike Stump9ccb1032009-05-23 22:01:27 +0000140 return;
Mike Stump49d1cd52009-05-26 22:03:21 +0000141 // If the source is volatile, we must read from it; to do that, we need
142 // some place to put it.
143 DestPtr = CGF.CreateTempAlloca(CGF.ConvertType(E->getType()), "agg.tmp");
Mike Stump9ccb1032009-05-23 22:01:27 +0000144 }
Chris Lattner883f6a72007-08-11 00:04:45 +0000145
Mike Stump4ac20dd2009-05-23 20:28:01 +0000146 // If the result of the assignment is used, copy the LHS there also.
147 // FIXME: Pass VolatileDest as well. I think we also need to merge volatile
148 // from the source as well, as we can't eliminate it if either operand
149 // is volatile, unless copy has volatile for both source and destination..
Mike Stump27fe2e62009-05-23 22:29:41 +0000150 CGF.EmitAggregateCopy(DestPtr, Src.getAggregateAddr(), E->getType(),
151 VolatileDest|Src.isVolatileQualified());
Mike Stump4ac20dd2009-05-23 20:28:01 +0000152}
153
154/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
Mike Stump49d1cd52009-05-26 22:03:21 +0000155void AggExprEmitter::EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore) {
Mike Stump4ac20dd2009-05-23 20:28:01 +0000156 assert(Src.isSimple() && "Can't have aggregate bitfield, vector, etc");
157
158 EmitFinalDestCopy(E, RValue::getAggregate(Src.getAddress(),
Mike Stump49d1cd52009-05-26 22:03:21 +0000159 Src.isVolatileQualified()),
160 Ignore);
Chris Lattner883f6a72007-08-11 00:04:45 +0000161}
162
Chris Lattneree755f92007-08-21 04:59:27 +0000163//===----------------------------------------------------------------------===//
164// Visitor Methods
165//===----------------------------------------------------------------------===//
166
Nuno Lopes7e916272009-01-15 20:14:33 +0000167void AggExprEmitter::VisitCStyleCastExpr(CStyleCastExpr *E) {
168 // GCC union extension
169 if (E->getType()->isUnionType()) {
170 RecordDecl *SD = E->getType()->getAsRecordType()->getDecl();
Douglas Gregor6ab35242009-04-09 21:40:53 +0000171 LValue FieldLoc = CGF.EmitLValueForField(DestPtr,
172 *SD->field_begin(CGF.getContext()),
173 true, 0);
Nuno Lopes7e916272009-01-15 20:14:33 +0000174 EmitInitializationToLValue(E->getSubExpr(), FieldLoc);
175 return;
176 }
177
178 Visit(E->getSubExpr());
179}
180
Chris Lattner96196622008-07-26 22:37:01 +0000181void AggExprEmitter::VisitImplicitCastExpr(ImplicitCastExpr *E) {
Eli Friedman2dce5f82009-05-28 23:04:00 +0000182 assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
183 E->getType()) &&
Chris Lattner96196622008-07-26 22:37:01 +0000184 "Implicit cast types must be compatible");
Anders Carlssone4707ff2008-01-14 06:28:57 +0000185 Visit(E->getSubExpr());
186}
187
Chris Lattner96196622008-07-26 22:37:01 +0000188void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
Anders Carlssone70e8f72009-05-27 16:45:02 +0000189 if (E->getCallReturnType()->isReferenceType()) {
190 EmitAggLoadOfLValue(E);
191 return;
192 }
193
Anders Carlsson148fe672007-10-31 22:04:46 +0000194 RValue RV = CGF.EmitCallExpr(E);
Mike Stump4ac20dd2009-05-23 20:28:01 +0000195 EmitFinalDestCopy(E, RV);
Anders Carlsson148fe672007-10-31 22:04:46 +0000196}
Chris Lattner96196622008-07-26 22:37:01 +0000197
198void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
Daniel Dunbar8f2926b2008-08-23 03:46:30 +0000199 RValue RV = CGF.EmitObjCMessageExpr(E);
Mike Stump4ac20dd2009-05-23 20:28:01 +0000200 EmitFinalDestCopy(E, RV);
Chris Lattner8fdf3282008-06-24 17:04:18 +0000201}
Anders Carlsson148fe672007-10-31 22:04:46 +0000202
Daniel Dunbar9c3fc702008-08-27 06:57:25 +0000203void AggExprEmitter::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
204 RValue RV = CGF.EmitObjCPropertyGet(E);
Mike Stump4ac20dd2009-05-23 20:28:01 +0000205 EmitFinalDestCopy(E, RV);
Daniel Dunbar9c3fc702008-08-27 06:57:25 +0000206}
207
Fariborz Jahanian5daf5702008-11-22 18:39:36 +0000208void AggExprEmitter::VisitObjCKVCRefExpr(ObjCKVCRefExpr *E) {
209 RValue RV = CGF.EmitObjCPropertyGet(E);
Mike Stump4ac20dd2009-05-23 20:28:01 +0000210 EmitFinalDestCopy(E, RV);
Fariborz Jahanian5daf5702008-11-22 18:39:36 +0000211}
212
Chris Lattner96196622008-07-26 22:37:01 +0000213void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
Mike Stump7f79f9b2009-05-29 15:46:01 +0000214 CGF.EmitAnyExpr(E->getLHS(), 0, false, true);
Mike Stumpf1b97f22009-05-23 21:40:07 +0000215 CGF.EmitAggExpr(E->getRHS(), DestPtr, VolatileDest);
Eli Friedman07fa52a2008-05-20 07:56:31 +0000216}
217
Chris Lattnerb2d963f2007-08-31 22:54:14 +0000218void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
219 CGF.EmitCompoundStmt(*E->getSubStmt(), true, DestPtr, VolatileDest);
220}
221
Chris Lattner9c033562007-08-21 04:25:47 +0000222void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
Daniel Dunbar488e9932008-08-16 00:56:44 +0000223 CGF.ErrorUnsupported(E, "aggregate binary expression");
Chris Lattneree755f92007-08-21 04:59:27 +0000224}
225
Chris Lattner03d6fb92007-08-21 04:43:17 +0000226void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
Eli Friedmanff6e2b72008-02-11 01:09:17 +0000227 // For an assignment to work, the value on the right has
228 // to be compatible with the value on the left.
Eli Friedman2dce5f82009-05-28 23:04:00 +0000229 assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
230 E->getRHS()->getType())
Eli Friedmanff6e2b72008-02-11 01:09:17 +0000231 && "Invalid assignment");
Chris Lattner9c033562007-08-21 04:25:47 +0000232 LValue LHS = CGF.EmitLValue(E->getLHS());
Chris Lattner883f6a72007-08-11 00:04:45 +0000233
Daniel Dunbar7f8ea5c2008-08-30 05:35:15 +0000234 // We have to special case property setters, otherwise we must have
235 // a simple lvalue (no aggregates inside vectors, bitfields).
236 if (LHS.isPropertyRef()) {
Daniel Dunbar7f8ea5c2008-08-30 05:35:15 +0000237 llvm::Value *AggLoc = DestPtr;
238 if (!AggLoc)
239 AggLoc = CGF.CreateTempAlloca(CGF.ConvertType(E->getRHS()->getType()));
Mike Stump240993d2009-05-23 23:48:13 +0000240 CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest);
Daniel Dunbar7f8ea5c2008-08-30 05:35:15 +0000241 CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(),
Mike Stump240993d2009-05-23 23:48:13 +0000242 RValue::getAggregate(AggLoc, VolatileDest));
Fariborz Jahanian43f44702008-11-22 22:30:21 +0000243 }
244 else if (LHS.isKVCRef()) {
Fariborz Jahanian43f44702008-11-22 22:30:21 +0000245 llvm::Value *AggLoc = DestPtr;
246 if (!AggLoc)
247 AggLoc = CGF.CreateTempAlloca(CGF.ConvertType(E->getRHS()->getType()));
Mike Stumpa49af1a2009-05-23 23:52:31 +0000248 CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest);
Fariborz Jahanian43f44702008-11-22 22:30:21 +0000249 CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(),
Mike Stumpa49af1a2009-05-23 23:52:31 +0000250 RValue::getAggregate(AggLoc, VolatileDest));
Daniel Dunbar7f8ea5c2008-08-30 05:35:15 +0000251 } else {
252 // Codegen the RHS so that it stores directly into the LHS.
Mike Stumpfde64202009-05-23 04:13:59 +0000253 CGF.EmitAggExpr(E->getRHS(), LHS.getAddress(), LHS.isVolatileQualified());
Mike Stump49d1cd52009-05-26 22:03:21 +0000254 EmitFinalDestCopy(E, LHS, true);
Daniel Dunbar7f8ea5c2008-08-30 05:35:15 +0000255 }
Chris Lattner883f6a72007-08-11 00:04:45 +0000256}
257
Chris Lattner9c033562007-08-21 04:25:47 +0000258void AggExprEmitter::VisitConditionalOperator(const ConditionalOperator *E) {
Daniel Dunbar9615ecb2008-11-13 01:38:36 +0000259 llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
260 llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
261 llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
Chris Lattner883f6a72007-08-11 00:04:45 +0000262
Chris Lattner9c033562007-08-21 04:25:47 +0000263 llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
Chris Lattnerbfc0c1a2007-08-26 23:13:56 +0000264 Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
Chris Lattner883f6a72007-08-11 00:04:45 +0000265
Chris Lattner9c033562007-08-21 04:25:47 +0000266 CGF.EmitBlock(LHSBlock);
Chris Lattner883f6a72007-08-11 00:04:45 +0000267
268 // Handle the GNU extension for missing LHS.
269 assert(E->getLHS() && "Must have LHS for aggregate value");
270
Chris Lattnerc748f272007-08-21 05:02:10 +0000271 Visit(E->getLHS());
Daniel Dunbard57a8712008-11-11 09:41:28 +0000272 CGF.EmitBranch(ContBlock);
Chris Lattner883f6a72007-08-11 00:04:45 +0000273
Chris Lattner9c033562007-08-21 04:25:47 +0000274 CGF.EmitBlock(RHSBlock);
Chris Lattner883f6a72007-08-11 00:04:45 +0000275
Chris Lattnerc748f272007-08-21 05:02:10 +0000276 Visit(E->getRHS());
Daniel Dunbard57a8712008-11-11 09:41:28 +0000277 CGF.EmitBranch(ContBlock);
Chris Lattner883f6a72007-08-11 00:04:45 +0000278
Chris Lattner9c033562007-08-21 04:25:47 +0000279 CGF.EmitBlock(ContBlock);
Chris Lattner883f6a72007-08-11 00:04:45 +0000280}
Chris Lattneree755f92007-08-21 04:59:27 +0000281
Eli Friedmanb1851242008-05-27 15:51:49 +0000282void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
Daniel Dunbar07855702009-02-11 22:25:55 +0000283 llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr());
Anders Carlssonddf7cac2008-11-04 05:30:00 +0000284 llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType());
285
Sebastian Redl0262f022009-01-09 21:09:38 +0000286 if (!ArgPtr) {
Anders Carlssonddf7cac2008-11-04 05:30:00 +0000287 CGF.ErrorUnsupported(VE, "aggregate va_arg expression");
Sebastian Redl0262f022009-01-09 21:09:38 +0000288 return;
289 }
290
Mike Stump4ac20dd2009-05-23 20:28:01 +0000291 EmitFinalDestCopy(VE, LValue::MakeAddr(ArgPtr, 0));
Eli Friedmanb1851242008-05-27 15:51:49 +0000292}
293
Anders Carlssonb58d0172009-05-30 23:23:33 +0000294void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
295 llvm::Value *Val = DestPtr;
296
297 if (!Val) {
298 // Create a temporary variable.
299 Val = CGF.CreateTempAlloca(CGF.ConvertTypeForMem(E->getType()), "tmp");
300
301 // FIXME: volatile
302 CGF.EmitAggExpr(E->getSubExpr(), Val, false);
303 } else
304 Visit(E->getSubExpr());
305
Anders Carlsson543ac0c2009-05-31 00:34:10 +0000306 CGF.PushCXXTemporary(E->getTemporary(), Val);
Anders Carlssonb58d0172009-05-30 23:23:33 +0000307}
308
Anders Carlssonb14095a2009-04-17 00:06:03 +0000309void
Anders Carlsson31ccf372009-05-03 17:47:16 +0000310AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) {
Anders Carlssonb58d0172009-05-30 23:23:33 +0000311 llvm::Value *Val = DestPtr;
312
313 if (!Val) {
314 // Create a temporary variable.
315 Val = CGF.CreateTempAlloca(CGF.ConvertTypeForMem(E->getType()), "tmp");
316 }
Anders Carlsson8e587a12009-05-30 20:56:46 +0000317
Anders Carlssonb58d0172009-05-30 23:23:33 +0000318 CGF.EmitCXXConstructExpr(Val, E);
Anders Carlsson7f6ad152009-05-19 04:48:36 +0000319}
320
321void AggExprEmitter::VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
Anders Carlssonb58d0172009-05-30 23:23:33 +0000322 CGF.EmitCXXExprWithTemporaries(E, DestPtr, VolatileDest);
Anders Carlssonb14095a2009-04-17 00:06:03 +0000323}
324
Chris Lattnerf81557c2008-04-04 18:42:16 +0000325void AggExprEmitter::EmitInitializationToLValue(Expr* E, LValue LV) {
Mike Stump7f79f9b2009-05-29 15:46:01 +0000326 // FIXME: Ignore result?
Chris Lattnerf81557c2008-04-04 18:42:16 +0000327 // FIXME: Are initializers affected by volatile?
Douglas Gregor3498bdb2009-01-29 17:44:32 +0000328 if (isa<ImplicitValueInitExpr>(E)) {
Douglas Gregor4c678342009-01-28 21:54:33 +0000329 EmitNullInitializationToLValue(LV, E->getType());
Douglas Gregor3498bdb2009-01-29 17:44:32 +0000330 } else if (E->getType()->isComplexType()) {
331 CGF.EmitComplexExprIntoAddr(E, LV.getAddress(), false);
Eli Friedmanc8ba9612008-05-12 15:06:05 +0000332 } else if (CGF.hasAggregateLLVMType(E->getType())) {
333 CGF.EmitAnyExpr(E, LV.getAddress(), false);
334 } else {
335 CGF.EmitStoreThroughLValue(CGF.EmitAnyExpr(E), LV, E->getType());
Chris Lattnerf81557c2008-04-04 18:42:16 +0000336 }
Chris Lattnerf81557c2008-04-04 18:42:16 +0000337}
338
339void AggExprEmitter::EmitNullInitializationToLValue(LValue LV, QualType T) {
340 if (!CGF.hasAggregateLLVMType(T)) {
341 // For non-aggregates, we can store zero
Daniel Dunbar82397132008-08-06 05:32:55 +0000342 llvm::Value *Null = llvm::Constant::getNullValue(CGF.ConvertType(T));
343 CGF.EmitStoreThroughLValue(RValue::get(Null), LV, T);
Lauro Ramos Venancio145cd892008-02-19 19:27:31 +0000344 } else {
Chris Lattnerf81557c2008-04-04 18:42:16 +0000345 // Otherwise, just memset the whole thing to zero. This is legal
346 // because in LLVM, all default initializers are guaranteed to have a
347 // bit pattern of all zeros.
Eli Friedman0f593122009-04-13 21:47:26 +0000348 // FIXME: That isn't true for member pointers!
Chris Lattnerf81557c2008-04-04 18:42:16 +0000349 // There's a potential optimization opportunity in combining
350 // memsets; that would be easy for arrays, but relatively
351 // difficult for structures with the current code.
Eli Friedmanccf0ed82009-03-28 03:10:45 +0000352 CGF.EmitMemSetToZero(LV.getAddress(), T);
Chris Lattnerf81557c2008-04-04 18:42:16 +0000353 }
354}
355
Chris Lattnerf81557c2008-04-04 18:42:16 +0000356void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
Eli Friedmana385b3c2008-12-02 01:17:45 +0000357#if 0
358 // FIXME: Disabled while we figure out what to do about
359 // test/CodeGen/bitfield.c
360 //
Mike Stumpf5408fe2009-05-16 07:57:57 +0000361 // If we can, prefer a copy from a global; this is a lot less code for long
362 // globals, and it's easier for the current optimizers to analyze.
363 // FIXME: Should we really be doing this? Should we try to avoid cases where
364 // we emit a global with a lot of zeros? Should we try to avoid short
365 // globals?
Eli Friedmanc9e8f602009-01-25 02:32:41 +0000366 if (E->isConstantInitializer(CGF.getContext(), 0)) {
Eli Friedman994ffef2008-11-30 02:11:09 +0000367 llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, &CGF);
368 llvm::GlobalVariable* GV =
369 new llvm::GlobalVariable(C->getType(), true,
370 llvm::GlobalValue::InternalLinkage,
371 C, "", &CGF.CGM.getModule(), 0);
Mike Stump4ac20dd2009-05-23 20:28:01 +0000372 EmitFinalDestCopy(E, LValue::MakeAddr(GV, 0));
Eli Friedman994ffef2008-11-30 02:11:09 +0000373 return;
374 }
Eli Friedmana385b3c2008-12-02 01:17:45 +0000375#endif
Douglas Gregora9c87802009-01-29 19:42:23 +0000376 if (E->hadArrayRangeDesignator()) {
377 CGF.ErrorUnsupported(E, "GNU array range designator extension");
378 }
379
Chris Lattnerf81557c2008-04-04 18:42:16 +0000380 // Handle initialization of an array.
381 if (E->getType()->isArrayType()) {
382 const llvm::PointerType *APType =
383 cast<llvm::PointerType>(DestPtr->getType());
384 const llvm::ArrayType *AType =
385 cast<llvm::ArrayType>(APType->getElementType());
386
387 uint64_t NumInitElements = E->getNumInits();
Eli Friedman922696f2008-05-19 17:51:16 +0000388
Chris Lattner96196622008-07-26 22:37:01 +0000389 if (E->getNumInits() > 0) {
390 QualType T1 = E->getType();
391 QualType T2 = E->getInit(0)->getType();
Eli Friedman2dce5f82009-05-28 23:04:00 +0000392 if (CGF.getContext().hasSameUnqualifiedType(T1, T2)) {
Chris Lattner96196622008-07-26 22:37:01 +0000393 EmitAggLoadOfLValue(E->getInit(0));
394 return;
395 }
Eli Friedman922696f2008-05-19 17:51:16 +0000396 }
397
Chris Lattnerf81557c2008-04-04 18:42:16 +0000398 uint64_t NumArrayElements = AType->getNumElements();
Chris Lattnerc63a1f22008-08-04 07:31:14 +0000399 QualType ElementType = CGF.getContext().getCanonicalType(E->getType());
Douglas Gregor4c678342009-01-28 21:54:33 +0000400 ElementType = CGF.getContext().getAsArrayType(ElementType)->getElementType();
Chris Lattnerf81557c2008-04-04 18:42:16 +0000401
Chris Lattnerc63a1f22008-08-04 07:31:14 +0000402 unsigned CVRqualifier = ElementType.getCVRQualifiers();
Eli Friedman1e692ac2008-06-13 23:01:12 +0000403
Chris Lattnerf81557c2008-04-04 18:42:16 +0000404 for (uint64_t i = 0; i != NumArrayElements; ++i) {
405 llvm::Value *NextVal = Builder.CreateStructGEP(DestPtr, i, ".array");
406 if (i < NumInitElements)
Eli Friedman1e692ac2008-06-13 23:01:12 +0000407 EmitInitializationToLValue(E->getInit(i),
408 LValue::MakeAddr(NextVal, CVRqualifier));
Chris Lattnerf81557c2008-04-04 18:42:16 +0000409 else
Eli Friedman1e692ac2008-06-13 23:01:12 +0000410 EmitNullInitializationToLValue(LValue::MakeAddr(NextVal, CVRqualifier),
Chris Lattnerf81557c2008-04-04 18:42:16 +0000411 ElementType);
Lauro Ramos Venancio145cd892008-02-19 19:27:31 +0000412 }
Chris Lattnerf81557c2008-04-04 18:42:16 +0000413 return;
414 }
415
416 assert(E->getType()->isRecordType() && "Only support structs/unions here!");
417
418 // Do struct initialization; this code just sets each individual member
419 // to the approprate value. This makes bitfield support automatic;
420 // the disadvantage is that the generated code is more difficult for
421 // the optimizer, especially with bitfields.
422 unsigned NumInitElements = E->getNumInits();
423 RecordDecl *SD = E->getType()->getAsRecordType()->getDecl();
Chris Lattnerf81557c2008-04-04 18:42:16 +0000424 unsigned CurInitVal = 0;
Douglas Gregor0bb76892009-01-29 16:53:55 +0000425
426 if (E->getType()->isUnionType()) {
427 // Only initialize one field of a union. The field itself is
428 // specified by the initializer list.
429 if (!E->getInitializedFieldInUnion()) {
430 // Empty union; we have nothing to do.
431
432#ifndef NDEBUG
433 // Make sure that it's really an empty and not a failure of
434 // semantic analysis.
Douglas Gregor6ab35242009-04-09 21:40:53 +0000435 for (RecordDecl::field_iterator Field = SD->field_begin(CGF.getContext()),
436 FieldEnd = SD->field_end(CGF.getContext());
Douglas Gregor0bb76892009-01-29 16:53:55 +0000437 Field != FieldEnd; ++Field)
438 assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
439#endif
440 return;
441 }
442
443 // FIXME: volatility
444 FieldDecl *Field = E->getInitializedFieldInUnion();
445 LValue FieldLoc = CGF.EmitLValueForField(DestPtr, Field, true, 0);
446
447 if (NumInitElements) {
448 // Store the initializer into the field
449 EmitInitializationToLValue(E->getInit(0), FieldLoc);
450 } else {
451 // Default-initialize to null
452 EmitNullInitializationToLValue(FieldLoc, Field->getType());
453 }
454
455 return;
456 }
Chris Lattnerf81557c2008-04-04 18:42:16 +0000457
458 // Here we iterate over the fields; this makes it simpler to both
459 // default-initialize fields and skip over unnamed fields.
Douglas Gregor6ab35242009-04-09 21:40:53 +0000460 for (RecordDecl::field_iterator Field = SD->field_begin(CGF.getContext()),
461 FieldEnd = SD->field_end(CGF.getContext());
Douglas Gregor44b43212008-12-11 16:49:14 +0000462 Field != FieldEnd; ++Field) {
463 // We're done once we hit the flexible array member
464 if (Field->getType()->isIncompleteArrayType())
465 break;
466
Douglas Gregor34e79462009-01-28 23:36:17 +0000467 if (Field->isUnnamedBitfield())
Chris Lattnerf81557c2008-04-04 18:42:16 +0000468 continue;
Douglas Gregor34e79462009-01-28 23:36:17 +0000469
Eli Friedman1e692ac2008-06-13 23:01:12 +0000470 // FIXME: volatility
Douglas Gregor0bb76892009-01-29 16:53:55 +0000471 LValue FieldLoc = CGF.EmitLValueForField(DestPtr, *Field, false, 0);
Fariborz Jahanian14674ff2009-05-27 19:54:11 +0000472 // We never generate write-barries for initialized fields.
473 LValue::SetObjCNonGC(FieldLoc, true);
Chris Lattnerf81557c2008-04-04 18:42:16 +0000474 if (CurInitVal < NumInitElements) {
475 // Store the initializer into the field
Chris Lattnerf81557c2008-04-04 18:42:16 +0000476 EmitInitializationToLValue(E->getInit(CurInitVal++), FieldLoc);
477 } else {
478 // We're out of initalizers; default-initialize to null
Douglas Gregor44b43212008-12-11 16:49:14 +0000479 EmitNullInitializationToLValue(FieldLoc, Field->getType());
Chris Lattnerf81557c2008-04-04 18:42:16 +0000480 }
Lauro Ramos Venancio145cd892008-02-19 19:27:31 +0000481 }
Devang Patel636c3d02007-10-26 17:44:44 +0000482}
483
Chris Lattneree755f92007-08-21 04:59:27 +0000484//===----------------------------------------------------------------------===//
485// Entry Points into this File
486//===----------------------------------------------------------------------===//
487
Mike Stumpe1129a92009-05-26 18:57:45 +0000488/// EmitAggExpr - Emit the computation of the specified expression of aggregate
489/// type. The result is computed into DestPtr. Note that if DestPtr is null,
490/// the value of the aggregate expression is not needed. If VolatileDest is
491/// true, DestPtr cannot be 0.
Chris Lattneree755f92007-08-21 04:59:27 +0000492void CodeGenFunction::EmitAggExpr(const Expr *E, llvm::Value *DestPtr,
Mike Stump49d1cd52009-05-26 22:03:21 +0000493 bool VolatileDest, bool IgnoreResult) {
Chris Lattneree755f92007-08-21 04:59:27 +0000494 assert(E && hasAggregateLLVMType(E->getType()) &&
495 "Invalid aggregate expression to emit");
Mike Stumpe1129a92009-05-26 18:57:45 +0000496 assert ((DestPtr != 0 || VolatileDest == false)
497 && "volatile aggregate can't be 0");
Chris Lattneree755f92007-08-21 04:59:27 +0000498
Mike Stump49d1cd52009-05-26 22:03:21 +0000499 AggExprEmitter(*this, DestPtr, VolatileDest, IgnoreResult)
500 .Visit(const_cast<Expr*>(E));
Chris Lattneree755f92007-08-21 04:59:27 +0000501}
Daniel Dunbar7482d122008-09-09 20:49:46 +0000502
503void CodeGenFunction::EmitAggregateClear(llvm::Value *DestPtr, QualType Ty) {
504 assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
505
506 EmitMemSetToZero(DestPtr, Ty);
507}
508
509void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr,
Mike Stump27fe2e62009-05-23 22:29:41 +0000510 llvm::Value *SrcPtr, QualType Ty,
511 bool isVolatile) {
Daniel Dunbar7482d122008-09-09 20:49:46 +0000512 assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
513
Chris Lattner83c96292009-02-28 18:31:01 +0000514 // Aggregate assignment turns into llvm.memcpy. This is almost valid per
Chris Lattnerca4fc2c2009-02-28 18:18:58 +0000515 // C99 6.5.16.1p3, which states "If the value being stored in an object is
516 // read from another object that overlaps in anyway the storage of the first
517 // object, then the overlap shall be exact and the two objects shall have
518 // qualified or unqualified versions of a compatible type."
519 //
Chris Lattner83c96292009-02-28 18:31:01 +0000520 // memcpy is not defined if the source and destination pointers are exactly
Chris Lattnerca4fc2c2009-02-28 18:18:58 +0000521 // equal, but other compilers do this optimization, and almost every memcpy
522 // implementation handles this case safely. If there is a libc that does not
523 // safely handle this, we can add a target hook.
Daniel Dunbar7482d122008-09-09 20:49:46 +0000524 const llvm::Type *BP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
525 if (DestPtr->getType() != BP)
526 DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp");
527 if (SrcPtr->getType() != BP)
528 SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp");
529
530 // Get size and alignment info for this aggregate.
531 std::pair<uint64_t, unsigned> TypeInfo = getContext().getTypeInfo(Ty);
532
533 // FIXME: Handle variable sized types.
534 const llvm::Type *IntPtr = llvm::IntegerType::get(LLVMPointerWidth);
535
Mike Stumpfde64202009-05-23 04:13:59 +0000536 // FIXME: If we have a volatile struct, the optimizer can remove what might
537 // appear to be `extra' memory ops:
538 //
539 // volatile struct { int i; } a, b;
540 //
541 // int main() {
542 // a = b;
543 // a = b;
544 // }
545 //
Mike Stump49d1cd52009-05-26 22:03:21 +0000546 // we need to use a differnt call here. We use isVolatile to indicate when
547 // either the source or the destination is volatile.
Chris Lattnerca4fc2c2009-02-28 18:18:58 +0000548 Builder.CreateCall4(CGM.getMemCpyFn(),
Daniel Dunbar7482d122008-09-09 20:49:46 +0000549 DestPtr, SrcPtr,
550 // TypeInfo.first describes size in bits.
551 llvm::ConstantInt::get(IntPtr, TypeInfo.first/8),
552 llvm::ConstantInt::get(llvm::Type::Int32Ty,
553 TypeInfo.second/8));
554}