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Chris Lattner59907c42007-08-10 20:18:51 +00001//===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===//
2//
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 Lattner59907c42007-08-10 20:18:51 +00007//
8//===----------------------------------------------------------------------===//
9//
Mike Stump1eb44332009-09-09 15:08:12 +000010// This file implements extra semantic analysis beyond what is enforced
Chris Lattner59907c42007-08-10 20:18:51 +000011// by the C type system.
12//
13//===----------------------------------------------------------------------===//
14
15#include "Sema.h"
Ted Kremeneke0e53132010-01-28 23:39:18 +000016#include "clang/Analysis/Analyses/PrintfFormatString.h"
Chris Lattner59907c42007-08-10 20:18:51 +000017#include "clang/AST/ASTContext.h"
Ken Dyck199c3d62010-01-11 17:06:35 +000018#include "clang/AST/CharUnits.h"
Daniel Dunbarc4a1dea2008-08-11 05:35:13 +000019#include "clang/AST/DeclObjC.h"
Ted Kremenek23245122007-08-20 16:18:38 +000020#include "clang/AST/ExprCXX.h"
Ted Kremenek7ff22b22008-06-16 18:00:42 +000021#include "clang/AST/ExprObjC.h"
Mike Stumpf8c49212010-01-21 03:59:47 +000022#include "clang/AST/DeclObjC.h"
23#include "clang/AST/StmtCXX.h"
24#include "clang/AST/StmtObjC.h"
Chris Lattner719e6152009-02-18 19:21:10 +000025#include "clang/Lex/LiteralSupport.h"
Chris Lattner59907c42007-08-10 20:18:51 +000026#include "clang/Lex/Preprocessor.h"
Mike Stumpf8c49212010-01-21 03:59:47 +000027#include "llvm/ADT/BitVector.h"
28#include "llvm/ADT/STLExtras.h"
Eric Christopher691ebc32010-04-17 02:26:23 +000029#include "clang/Basic/TargetBuiltins.h"
Zhongxing Xua1f3dba2009-05-20 01:55:10 +000030#include <limits>
Chris Lattner59907c42007-08-10 20:18:51 +000031using namespace clang;
32
Chris Lattner60800082009-02-18 17:49:48 +000033/// getLocationOfStringLiteralByte - Return a source location that points to the
34/// specified byte of the specified string literal.
35///
36/// Strings are amazingly complex. They can be formed from multiple tokens and
37/// can have escape sequences in them in addition to the usual trigraph and
38/// escaped newline business. This routine handles this complexity.
39///
40SourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL,
41 unsigned ByteNo) const {
42 assert(!SL->isWide() && "This doesn't work for wide strings yet");
Mike Stump1eb44332009-09-09 15:08:12 +000043
Chris Lattner60800082009-02-18 17:49:48 +000044 // Loop over all of the tokens in this string until we find the one that
45 // contains the byte we're looking for.
46 unsigned TokNo = 0;
47 while (1) {
48 assert(TokNo < SL->getNumConcatenated() && "Invalid byte number!");
49 SourceLocation StrTokLoc = SL->getStrTokenLoc(TokNo);
Mike Stump1eb44332009-09-09 15:08:12 +000050
Chris Lattner60800082009-02-18 17:49:48 +000051 // Get the spelling of the string so that we can get the data that makes up
52 // the string literal, not the identifier for the macro it is potentially
53 // expanded through.
54 SourceLocation StrTokSpellingLoc = SourceMgr.getSpellingLoc(StrTokLoc);
55
56 // Re-lex the token to get its length and original spelling.
57 std::pair<FileID, unsigned> LocInfo =
58 SourceMgr.getDecomposedLoc(StrTokSpellingLoc);
Douglas Gregorf715ca12010-03-16 00:06:06 +000059 bool Invalid = false;
Benjamin Kramerf6ac97b2010-03-16 14:14:31 +000060 llvm::StringRef Buffer = SourceMgr.getBufferData(LocInfo.first, &Invalid);
Douglas Gregorf715ca12010-03-16 00:06:06 +000061 if (Invalid)
Douglas Gregoraea67db2010-03-15 22:54:52 +000062 return StrTokSpellingLoc;
63
Benjamin Kramerf6ac97b2010-03-16 14:14:31 +000064 const char *StrData = Buffer.data()+LocInfo.second;
Mike Stump1eb44332009-09-09 15:08:12 +000065
Chris Lattner60800082009-02-18 17:49:48 +000066 // Create a langops struct and enable trigraphs. This is sufficient for
67 // relexing tokens.
68 LangOptions LangOpts;
69 LangOpts.Trigraphs = true;
Mike Stump1eb44332009-09-09 15:08:12 +000070
Chris Lattner60800082009-02-18 17:49:48 +000071 // Create a lexer starting at the beginning of this token.
Benjamin Kramerf6ac97b2010-03-16 14:14:31 +000072 Lexer TheLexer(StrTokSpellingLoc, LangOpts, Buffer.begin(), StrData,
73 Buffer.end());
Chris Lattner60800082009-02-18 17:49:48 +000074 Token TheTok;
75 TheLexer.LexFromRawLexer(TheTok);
Mike Stump1eb44332009-09-09 15:08:12 +000076
Chris Lattner443e53c2009-02-18 19:26:42 +000077 // Use the StringLiteralParser to compute the length of the string in bytes.
78 StringLiteralParser SLP(&TheTok, 1, PP);
79 unsigned TokNumBytes = SLP.GetStringLength();
Mike Stump1eb44332009-09-09 15:08:12 +000080
Chris Lattner2197c962009-02-18 18:52:52 +000081 // If the byte is in this token, return the location of the byte.
Chris Lattner60800082009-02-18 17:49:48 +000082 if (ByteNo < TokNumBytes ||
83 (ByteNo == TokNumBytes && TokNo == SL->getNumConcatenated())) {
Mike Stump1eb44332009-09-09 15:08:12 +000084 unsigned Offset =
Chris Lattner719e6152009-02-18 19:21:10 +000085 StringLiteralParser::getOffsetOfStringByte(TheTok, ByteNo, PP);
Mike Stump1eb44332009-09-09 15:08:12 +000086
Chris Lattner719e6152009-02-18 19:21:10 +000087 // Now that we know the offset of the token in the spelling, use the
88 // preprocessor to get the offset in the original source.
89 return PP.AdvanceToTokenCharacter(StrTokLoc, Offset);
Chris Lattner60800082009-02-18 17:49:48 +000090 }
Mike Stump1eb44332009-09-09 15:08:12 +000091
Chris Lattner60800082009-02-18 17:49:48 +000092 // Move to the next string token.
93 ++TokNo;
94 ByteNo -= TokNumBytes;
95 }
96}
97
Ryan Flynn4403a5e2009-08-06 03:00:50 +000098/// CheckablePrintfAttr - does a function call have a "printf" attribute
99/// and arguments that merit checking?
100bool Sema::CheckablePrintfAttr(const FormatAttr *Format, CallExpr *TheCall) {
101 if (Format->getType() == "printf") return true;
102 if (Format->getType() == "printf0") {
103 // printf0 allows null "format" string; if so don't check format/args
104 unsigned format_idx = Format->getFormatIdx() - 1;
Sebastian Redl4a2614e2009-11-17 18:02:24 +0000105 // Does the index refer to the implicit object argument?
106 if (isa<CXXMemberCallExpr>(TheCall)) {
107 if (format_idx == 0)
108 return false;
109 --format_idx;
110 }
Ryan Flynn4403a5e2009-08-06 03:00:50 +0000111 if (format_idx < TheCall->getNumArgs()) {
112 Expr *Format = TheCall->getArg(format_idx)->IgnoreParenCasts();
Ted Kremenekefaff192010-02-27 01:41:03 +0000113 if (!Format->isNullPointerConstant(Context,
114 Expr::NPC_ValueDependentIsNull))
Ryan Flynn4403a5e2009-08-06 03:00:50 +0000115 return true;
116 }
117 }
118 return false;
119}
Chris Lattner60800082009-02-18 17:49:48 +0000120
Sebastian Redl0eb23302009-01-19 00:08:26 +0000121Action::OwningExprResult
Anders Carlssond406bf02009-08-16 01:56:34 +0000122Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
Sebastian Redl0eb23302009-01-19 00:08:26 +0000123 OwningExprResult TheCallResult(Owned(TheCall));
Douglas Gregor2def4832008-11-17 20:34:05 +0000124
Anders Carlssond406bf02009-08-16 01:56:34 +0000125 switch (BuiltinID) {
Chris Lattner30ce3442007-12-19 23:59:04 +0000126 case Builtin::BI__builtin___CFStringMakeConstantString:
Chris Lattner925e60d2007-12-28 05:29:59 +0000127 assert(TheCall->getNumArgs() == 1 &&
Chris Lattner1b9a0792007-12-20 00:26:33 +0000128 "Wrong # arguments to builtin CFStringMakeConstantString");
Chris Lattner69039812009-02-18 06:01:06 +0000129 if (CheckObjCString(TheCall->getArg(0)))
Sebastian Redl0eb23302009-01-19 00:08:26 +0000130 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000131 break;
Ted Kremenek49ff7a12008-07-09 17:58:53 +0000132 case Builtin::BI__builtin_stdarg_start:
Chris Lattner30ce3442007-12-19 23:59:04 +0000133 case Builtin::BI__builtin_va_start:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000134 if (SemaBuiltinVAStart(TheCall))
135 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000136 break;
Chris Lattner1b9a0792007-12-20 00:26:33 +0000137 case Builtin::BI__builtin_isgreater:
138 case Builtin::BI__builtin_isgreaterequal:
139 case Builtin::BI__builtin_isless:
140 case Builtin::BI__builtin_islessequal:
141 case Builtin::BI__builtin_islessgreater:
142 case Builtin::BI__builtin_isunordered:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000143 if (SemaBuiltinUnorderedCompare(TheCall))
144 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000145 break;
Benjamin Kramere771a7a2010-02-15 22:42:31 +0000146 case Builtin::BI__builtin_fpclassify:
147 if (SemaBuiltinFPClassification(TheCall, 6))
148 return ExprError();
149 break;
Eli Friedman9ac6f622009-08-31 20:06:00 +0000150 case Builtin::BI__builtin_isfinite:
151 case Builtin::BI__builtin_isinf:
152 case Builtin::BI__builtin_isinf_sign:
153 case Builtin::BI__builtin_isnan:
154 case Builtin::BI__builtin_isnormal:
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000155 if (SemaBuiltinFPClassification(TheCall, 1))
Eli Friedman9ac6f622009-08-31 20:06:00 +0000156 return ExprError();
157 break;
Eli Friedman6cfda232008-05-20 08:23:37 +0000158 case Builtin::BI__builtin_return_address:
Eric Christopher691ebc32010-04-17 02:26:23 +0000159 case Builtin::BI__builtin_frame_address: {
160 llvm::APSInt Result;
161 if (SemaBuiltinConstantArg(TheCall, 0, Result))
Sebastian Redl0eb23302009-01-19 00:08:26 +0000162 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000163 break;
Eric Christopher691ebc32010-04-17 02:26:23 +0000164 }
165 case Builtin::BI__builtin_eh_return_data_regno: {
166 llvm::APSInt Result;
167 if (SemaBuiltinConstantArg(TheCall, 0, Result))
Chris Lattner21fb98e2009-09-23 06:06:36 +0000168 return ExprError();
169 break;
Eric Christopher691ebc32010-04-17 02:26:23 +0000170 }
Eli Friedmand38617c2008-05-14 19:38:39 +0000171 case Builtin::BI__builtin_shufflevector:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000172 return SemaBuiltinShuffleVector(TheCall);
173 // TheCall will be freed by the smart pointer here, but that's fine, since
174 // SemaBuiltinShuffleVector guts it, but then doesn't release it.
Daniel Dunbar4493f792008-07-21 22:59:13 +0000175 case Builtin::BI__builtin_prefetch:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000176 if (SemaBuiltinPrefetch(TheCall))
177 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000178 break;
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000179 case Builtin::BI__builtin_object_size:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000180 if (SemaBuiltinObjectSize(TheCall))
181 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000182 break;
Eli Friedmand875fed2009-05-03 04:46:36 +0000183 case Builtin::BI__builtin_longjmp:
184 if (SemaBuiltinLongjmp(TheCall))
185 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000186 break;
Chris Lattner5caa3702009-05-08 06:58:22 +0000187 case Builtin::BI__sync_fetch_and_add:
188 case Builtin::BI__sync_fetch_and_sub:
189 case Builtin::BI__sync_fetch_and_or:
190 case Builtin::BI__sync_fetch_and_and:
191 case Builtin::BI__sync_fetch_and_xor:
192 case Builtin::BI__sync_add_and_fetch:
193 case Builtin::BI__sync_sub_and_fetch:
194 case Builtin::BI__sync_and_and_fetch:
195 case Builtin::BI__sync_or_and_fetch:
196 case Builtin::BI__sync_xor_and_fetch:
197 case Builtin::BI__sync_val_compare_and_swap:
198 case Builtin::BI__sync_bool_compare_and_swap:
199 case Builtin::BI__sync_lock_test_and_set:
200 case Builtin::BI__sync_lock_release:
201 if (SemaBuiltinAtomicOverloaded(TheCall))
202 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000203 break;
Eric Christopher691ebc32010-04-17 02:26:23 +0000204
205 // Target specific builtins start here.
206 case X86::BI__builtin_ia32_palignr128:
207 case X86::BI__builtin_ia32_palignr: {
208 llvm::APSInt Result;
209 if (SemaBuiltinConstantArg(TheCall, 2, Result))
210 return ExprError();
211 break;
212 }
Anders Carlsson71993dd2007-08-17 05:31:46 +0000213 }
Mike Stump1eb44332009-09-09 15:08:12 +0000214
Anders Carlssond406bf02009-08-16 01:56:34 +0000215 return move(TheCallResult);
216}
Daniel Dunbarde454282008-10-02 18:44:07 +0000217
Anders Carlssond406bf02009-08-16 01:56:34 +0000218/// CheckFunctionCall - Check a direct function call for various correctness
219/// and safety properties not strictly enforced by the C type system.
220bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall) {
221 // Get the IdentifierInfo* for the called function.
222 IdentifierInfo *FnInfo = FDecl->getIdentifier();
223
224 // None of the checks below are needed for functions that don't have
225 // simple names (e.g., C++ conversion functions).
226 if (!FnInfo)
227 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000228
Daniel Dunbarde454282008-10-02 18:44:07 +0000229 // FIXME: This mechanism should be abstracted to be less fragile and
230 // more efficient. For example, just map function ids to custom
231 // handlers.
232
Chris Lattner59907c42007-08-10 20:18:51 +0000233 // Printf checking.
Argyrios Kyrtzidis40b598e2009-06-30 02:34:44 +0000234 if (const FormatAttr *Format = FDecl->getAttr<FormatAttr>()) {
Ryan Flynn4403a5e2009-08-06 03:00:50 +0000235 if (CheckablePrintfAttr(Format, TheCall)) {
Ted Kremenek3d692df2009-02-27 17:58:43 +0000236 bool HasVAListArg = Format->getFirstArg() == 0;
Douglas Gregor3c385e52009-02-14 18:57:46 +0000237 CheckPrintfArguments(TheCall, HasVAListArg, Format->getFormatIdx() - 1,
Ted Kremenek3d692df2009-02-27 17:58:43 +0000238 HasVAListArg ? 0 : Format->getFirstArg() - 1);
Douglas Gregor3c385e52009-02-14 18:57:46 +0000239 }
Chris Lattner59907c42007-08-10 20:18:51 +0000240 }
Mike Stump1eb44332009-09-09 15:08:12 +0000241
242 for (const NonNullAttr *NonNull = FDecl->getAttr<NonNullAttr>(); NonNull;
Anders Carlssond406bf02009-08-16 01:56:34 +0000243 NonNull = NonNull->getNext<NonNullAttr>())
244 CheckNonNullArguments(NonNull, TheCall);
Sebastian Redl0eb23302009-01-19 00:08:26 +0000245
Anders Carlssond406bf02009-08-16 01:56:34 +0000246 return false;
Anders Carlsson71993dd2007-08-17 05:31:46 +0000247}
248
Anders Carlssond406bf02009-08-16 01:56:34 +0000249bool Sema::CheckBlockCall(NamedDecl *NDecl, CallExpr *TheCall) {
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000250 // Printf checking.
Argyrios Kyrtzidis40b598e2009-06-30 02:34:44 +0000251 const FormatAttr *Format = NDecl->getAttr<FormatAttr>();
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000252 if (!Format)
Anders Carlssond406bf02009-08-16 01:56:34 +0000253 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000254
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000255 const VarDecl *V = dyn_cast<VarDecl>(NDecl);
256 if (!V)
Anders Carlssond406bf02009-08-16 01:56:34 +0000257 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000258
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000259 QualType Ty = V->getType();
260 if (!Ty->isBlockPointerType())
Anders Carlssond406bf02009-08-16 01:56:34 +0000261 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000262
Anders Carlssond406bf02009-08-16 01:56:34 +0000263 if (!CheckablePrintfAttr(Format, TheCall))
264 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000265
Anders Carlssond406bf02009-08-16 01:56:34 +0000266 bool HasVAListArg = Format->getFirstArg() == 0;
Anders Carlssond406bf02009-08-16 01:56:34 +0000267 CheckPrintfArguments(TheCall, HasVAListArg, Format->getFormatIdx() - 1,
268 HasVAListArg ? 0 : Format->getFirstArg() - 1);
269
270 return false;
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000271}
272
Chris Lattner5caa3702009-05-08 06:58:22 +0000273/// SemaBuiltinAtomicOverloaded - We have a call to a function like
274/// __sync_fetch_and_add, which is an overloaded function based on the pointer
275/// type of its first argument. The main ActOnCallExpr routines have already
276/// promoted the types of arguments because all of these calls are prototyped as
277/// void(...).
278///
279/// This function goes through and does final semantic checking for these
280/// builtins,
281bool Sema::SemaBuiltinAtomicOverloaded(CallExpr *TheCall) {
282 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
283 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
284
285 // Ensure that we have at least one argument to do type inference from.
286 if (TheCall->getNumArgs() < 1)
Eric Christopherd77b9a22010-04-16 04:48:22 +0000287 return Diag(TheCall->getLocEnd(),
288 diag::err_typecheck_call_too_few_args_at_least)
289 << 0 << 1 << TheCall->getNumArgs()
290 << TheCall->getCallee()->getSourceRange();
Mike Stump1eb44332009-09-09 15:08:12 +0000291
Chris Lattner5caa3702009-05-08 06:58:22 +0000292 // Inspect the first argument of the atomic builtin. This should always be
293 // a pointer type, whose element is an integral scalar or pointer type.
294 // Because it is a pointer type, we don't have to worry about any implicit
295 // casts here.
296 Expr *FirstArg = TheCall->getArg(0);
297 if (!FirstArg->getType()->isPointerType())
298 return Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
299 << FirstArg->getType() << FirstArg->getSourceRange();
Mike Stump1eb44332009-09-09 15:08:12 +0000300
Ted Kremenek6217b802009-07-29 21:53:49 +0000301 QualType ValType = FirstArg->getType()->getAs<PointerType>()->getPointeeType();
Mike Stump1eb44332009-09-09 15:08:12 +0000302 if (!ValType->isIntegerType() && !ValType->isPointerType() &&
Chris Lattner5caa3702009-05-08 06:58:22 +0000303 !ValType->isBlockPointerType())
304 return Diag(DRE->getLocStart(),
305 diag::err_atomic_builtin_must_be_pointer_intptr)
306 << FirstArg->getType() << FirstArg->getSourceRange();
307
308 // We need to figure out which concrete builtin this maps onto. For example,
309 // __sync_fetch_and_add with a 2 byte object turns into
310 // __sync_fetch_and_add_2.
311#define BUILTIN_ROW(x) \
312 { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \
313 Builtin::BI##x##_8, Builtin::BI##x##_16 }
Mike Stump1eb44332009-09-09 15:08:12 +0000314
Chris Lattner5caa3702009-05-08 06:58:22 +0000315 static const unsigned BuiltinIndices[][5] = {
316 BUILTIN_ROW(__sync_fetch_and_add),
317 BUILTIN_ROW(__sync_fetch_and_sub),
318 BUILTIN_ROW(__sync_fetch_and_or),
319 BUILTIN_ROW(__sync_fetch_and_and),
320 BUILTIN_ROW(__sync_fetch_and_xor),
Mike Stump1eb44332009-09-09 15:08:12 +0000321
Chris Lattner5caa3702009-05-08 06:58:22 +0000322 BUILTIN_ROW(__sync_add_and_fetch),
323 BUILTIN_ROW(__sync_sub_and_fetch),
324 BUILTIN_ROW(__sync_and_and_fetch),
325 BUILTIN_ROW(__sync_or_and_fetch),
326 BUILTIN_ROW(__sync_xor_and_fetch),
Mike Stump1eb44332009-09-09 15:08:12 +0000327
Chris Lattner5caa3702009-05-08 06:58:22 +0000328 BUILTIN_ROW(__sync_val_compare_and_swap),
329 BUILTIN_ROW(__sync_bool_compare_and_swap),
330 BUILTIN_ROW(__sync_lock_test_and_set),
331 BUILTIN_ROW(__sync_lock_release)
332 };
Mike Stump1eb44332009-09-09 15:08:12 +0000333#undef BUILTIN_ROW
334
Chris Lattner5caa3702009-05-08 06:58:22 +0000335 // Determine the index of the size.
336 unsigned SizeIndex;
Ken Dyck199c3d62010-01-11 17:06:35 +0000337 switch (Context.getTypeSizeInChars(ValType).getQuantity()) {
Chris Lattner5caa3702009-05-08 06:58:22 +0000338 case 1: SizeIndex = 0; break;
339 case 2: SizeIndex = 1; break;
340 case 4: SizeIndex = 2; break;
341 case 8: SizeIndex = 3; break;
342 case 16: SizeIndex = 4; break;
343 default:
344 return Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size)
345 << FirstArg->getType() << FirstArg->getSourceRange();
346 }
Mike Stump1eb44332009-09-09 15:08:12 +0000347
Chris Lattner5caa3702009-05-08 06:58:22 +0000348 // Each of these builtins has one pointer argument, followed by some number of
349 // values (0, 1 or 2) followed by a potentially empty varags list of stuff
350 // that we ignore. Find out which row of BuiltinIndices to read from as well
351 // as the number of fixed args.
Douglas Gregor7814e6d2009-09-12 00:22:50 +0000352 unsigned BuiltinID = FDecl->getBuiltinID();
Chris Lattner5caa3702009-05-08 06:58:22 +0000353 unsigned BuiltinIndex, NumFixed = 1;
354 switch (BuiltinID) {
355 default: assert(0 && "Unknown overloaded atomic builtin!");
356 case Builtin::BI__sync_fetch_and_add: BuiltinIndex = 0; break;
357 case Builtin::BI__sync_fetch_and_sub: BuiltinIndex = 1; break;
358 case Builtin::BI__sync_fetch_and_or: BuiltinIndex = 2; break;
359 case Builtin::BI__sync_fetch_and_and: BuiltinIndex = 3; break;
360 case Builtin::BI__sync_fetch_and_xor: BuiltinIndex = 4; break;
Mike Stump1eb44332009-09-09 15:08:12 +0000361
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000362 case Builtin::BI__sync_add_and_fetch: BuiltinIndex = 5; break;
363 case Builtin::BI__sync_sub_and_fetch: BuiltinIndex = 6; break;
364 case Builtin::BI__sync_and_and_fetch: BuiltinIndex = 7; break;
365 case Builtin::BI__sync_or_and_fetch: BuiltinIndex = 8; break;
366 case Builtin::BI__sync_xor_and_fetch: BuiltinIndex = 9; break;
Mike Stump1eb44332009-09-09 15:08:12 +0000367
Chris Lattner5caa3702009-05-08 06:58:22 +0000368 case Builtin::BI__sync_val_compare_and_swap:
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000369 BuiltinIndex = 10;
Chris Lattner5caa3702009-05-08 06:58:22 +0000370 NumFixed = 2;
371 break;
372 case Builtin::BI__sync_bool_compare_and_swap:
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000373 BuiltinIndex = 11;
Chris Lattner5caa3702009-05-08 06:58:22 +0000374 NumFixed = 2;
375 break;
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000376 case Builtin::BI__sync_lock_test_and_set: BuiltinIndex = 12; break;
Chris Lattner5caa3702009-05-08 06:58:22 +0000377 case Builtin::BI__sync_lock_release:
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000378 BuiltinIndex = 13;
Chris Lattner5caa3702009-05-08 06:58:22 +0000379 NumFixed = 0;
380 break;
381 }
Mike Stump1eb44332009-09-09 15:08:12 +0000382
Chris Lattner5caa3702009-05-08 06:58:22 +0000383 // Now that we know how many fixed arguments we expect, first check that we
384 // have at least that many.
385 if (TheCall->getNumArgs() < 1+NumFixed)
Eric Christopherd77b9a22010-04-16 04:48:22 +0000386 return Diag(TheCall->getLocEnd(),
387 diag::err_typecheck_call_too_few_args_at_least)
388 << 0 << 1+NumFixed << TheCall->getNumArgs()
389 << TheCall->getCallee()->getSourceRange();
Mike Stump1eb44332009-09-09 15:08:12 +0000390
391
Chris Lattnere7ac0a92009-05-08 15:36:58 +0000392 // Get the decl for the concrete builtin from this, we can tell what the
393 // concrete integer type we should convert to is.
394 unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex];
395 const char *NewBuiltinName = Context.BuiltinInfo.GetName(NewBuiltinID);
396 IdentifierInfo *NewBuiltinII = PP.getIdentifierInfo(NewBuiltinName);
Mike Stump1eb44332009-09-09 15:08:12 +0000397 FunctionDecl *NewBuiltinDecl =
Chris Lattnere7ac0a92009-05-08 15:36:58 +0000398 cast<FunctionDecl>(LazilyCreateBuiltin(NewBuiltinII, NewBuiltinID,
399 TUScope, false, DRE->getLocStart()));
400 const FunctionProtoType *BuiltinFT =
John McCall183700f2009-09-21 23:43:11 +0000401 NewBuiltinDecl->getType()->getAs<FunctionProtoType>();
Ted Kremenek6217b802009-07-29 21:53:49 +0000402 ValType = BuiltinFT->getArgType(0)->getAs<PointerType>()->getPointeeType();
Mike Stump1eb44332009-09-09 15:08:12 +0000403
Chris Lattnere7ac0a92009-05-08 15:36:58 +0000404 // If the first type needs to be converted (e.g. void** -> int*), do it now.
405 if (BuiltinFT->getArgType(0) != FirstArg->getType()) {
Eli Friedman73c39ab2009-10-20 08:27:19 +0000406 ImpCastExprToType(FirstArg, BuiltinFT->getArgType(0), CastExpr::CK_BitCast);
Chris Lattnere7ac0a92009-05-08 15:36:58 +0000407 TheCall->setArg(0, FirstArg);
408 }
Mike Stump1eb44332009-09-09 15:08:12 +0000409
Chris Lattner5caa3702009-05-08 06:58:22 +0000410 // Next, walk the valid ones promoting to the right type.
411 for (unsigned i = 0; i != NumFixed; ++i) {
412 Expr *Arg = TheCall->getArg(i+1);
Mike Stump1eb44332009-09-09 15:08:12 +0000413
Chris Lattner5caa3702009-05-08 06:58:22 +0000414 // If the argument is an implicit cast, then there was a promotion due to
415 // "...", just remove it now.
416 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) {
417 Arg = ICE->getSubExpr();
418 ICE->setSubExpr(0);
419 ICE->Destroy(Context);
420 TheCall->setArg(i+1, Arg);
421 }
Mike Stump1eb44332009-09-09 15:08:12 +0000422
Chris Lattner5caa3702009-05-08 06:58:22 +0000423 // GCC does an implicit conversion to the pointer or integer ValType. This
424 // can fail in some cases (1i -> int**), check for this error case now.
Anders Carlssoncdb61972009-08-07 22:21:05 +0000425 CastExpr::CastKind Kind = CastExpr::CK_Unknown;
Douglas Gregord6e44a32010-04-16 22:09:46 +0000426 if (CheckCastTypes(Arg->getSourceRange(), ValType, Arg, Kind))
Chris Lattner5caa3702009-05-08 06:58:22 +0000427 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000428
Chris Lattner5caa3702009-05-08 06:58:22 +0000429 // Okay, we have something that *can* be converted to the right type. Check
430 // to see if there is a potentially weird extension going on here. This can
431 // happen when you do an atomic operation on something like an char* and
432 // pass in 42. The 42 gets converted to char. This is even more strange
433 // for things like 45.123 -> char, etc.
Mike Stump1eb44332009-09-09 15:08:12 +0000434 // FIXME: Do this check.
Anders Carlsson88465d32010-04-23 22:18:37 +0000435 ImpCastExprToType(Arg, ValType, Kind, /*InheritancePath=*/0,
436 /*isLvalue=*/false);
Chris Lattner5caa3702009-05-08 06:58:22 +0000437 TheCall->setArg(i+1, Arg);
438 }
Mike Stump1eb44332009-09-09 15:08:12 +0000439
Chris Lattner5caa3702009-05-08 06:58:22 +0000440 // Switch the DeclRefExpr to refer to the new decl.
441 DRE->setDecl(NewBuiltinDecl);
442 DRE->setType(NewBuiltinDecl->getType());
Mike Stump1eb44332009-09-09 15:08:12 +0000443
Chris Lattner5caa3702009-05-08 06:58:22 +0000444 // Set the callee in the CallExpr.
445 // FIXME: This leaks the original parens and implicit casts.
446 Expr *PromotedCall = DRE;
447 UsualUnaryConversions(PromotedCall);
448 TheCall->setCallee(PromotedCall);
Mike Stump1eb44332009-09-09 15:08:12 +0000449
Chris Lattner5caa3702009-05-08 06:58:22 +0000450
451 // Change the result type of the call to match the result type of the decl.
452 TheCall->setType(NewBuiltinDecl->getResultType());
453 return false;
454}
455
456
Chris Lattner69039812009-02-18 06:01:06 +0000457/// CheckObjCString - Checks that the argument to the builtin
Anders Carlsson71993dd2007-08-17 05:31:46 +0000458/// CFString constructor is correct
Steve Narofffd942622009-04-13 20:26:29 +0000459/// FIXME: GCC currently emits the following warning:
Mike Stump1eb44332009-09-09 15:08:12 +0000460/// "warning: input conversion stopped due to an input byte that does not
Steve Narofffd942622009-04-13 20:26:29 +0000461/// belong to the input codeset UTF-8"
462/// Note: It might also make sense to do the UTF-16 conversion here (would
463/// simplify the backend).
Chris Lattner69039812009-02-18 06:01:06 +0000464bool Sema::CheckObjCString(Expr *Arg) {
Chris Lattner56f34942008-02-13 01:02:39 +0000465 Arg = Arg->IgnoreParenCasts();
Anders Carlsson71993dd2007-08-17 05:31:46 +0000466 StringLiteral *Literal = dyn_cast<StringLiteral>(Arg);
467
468 if (!Literal || Literal->isWide()) {
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000469 Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant)
470 << Arg->getSourceRange();
Anders Carlsson9cdc4d32007-08-17 15:44:17 +0000471 return true;
Anders Carlsson71993dd2007-08-17 05:31:46 +0000472 }
Mike Stump1eb44332009-09-09 15:08:12 +0000473
Daniel Dunbarf015b032009-09-22 10:03:52 +0000474 const char *Data = Literal->getStrData();
475 unsigned Length = Literal->getByteLength();
Mike Stump1eb44332009-09-09 15:08:12 +0000476
Daniel Dunbarf015b032009-09-22 10:03:52 +0000477 for (unsigned i = 0; i < Length; ++i) {
478 if (!Data[i]) {
479 Diag(getLocationOfStringLiteralByte(Literal, i),
480 diag::warn_cfstring_literal_contains_nul_character)
481 << Arg->getSourceRange();
482 break;
483 }
484 }
Mike Stump1eb44332009-09-09 15:08:12 +0000485
Anders Carlsson9cdc4d32007-08-17 15:44:17 +0000486 return false;
Chris Lattner59907c42007-08-10 20:18:51 +0000487}
488
Chris Lattnerc27c6652007-12-20 00:05:45 +0000489/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity.
490/// Emit an error and return true on failure, return false on success.
Chris Lattner925e60d2007-12-28 05:29:59 +0000491bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
492 Expr *Fn = TheCall->getCallee();
493 if (TheCall->getNumArgs() > 2) {
Chris Lattner2c21a072008-11-21 18:44:24 +0000494 Diag(TheCall->getArg(2)->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000495 diag::err_typecheck_call_too_many_args)
Eric Christopherccfa9632010-04-16 04:56:46 +0000496 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
497 << Fn->getSourceRange()
Mike Stump1eb44332009-09-09 15:08:12 +0000498 << SourceRange(TheCall->getArg(2)->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000499 (*(TheCall->arg_end()-1))->getLocEnd());
Chris Lattner30ce3442007-12-19 23:59:04 +0000500 return true;
501 }
Eli Friedman56f20ae2008-12-15 22:05:35 +0000502
503 if (TheCall->getNumArgs() < 2) {
Eric Christopherd77b9a22010-04-16 04:48:22 +0000504 return Diag(TheCall->getLocEnd(),
505 diag::err_typecheck_call_too_few_args_at_least)
506 << 0 /*function call*/ << 2 << TheCall->getNumArgs();
Eli Friedman56f20ae2008-12-15 22:05:35 +0000507 }
508
Chris Lattnerc27c6652007-12-20 00:05:45 +0000509 // Determine whether the current function is variadic or not.
Douglas Gregor9ea9bdb2010-03-01 23:15:13 +0000510 BlockScopeInfo *CurBlock = getCurBlock();
Chris Lattnerc27c6652007-12-20 00:05:45 +0000511 bool isVariadic;
Steve Naroffcd9c5142009-04-15 19:33:47 +0000512 if (CurBlock)
513 isVariadic = CurBlock->isVariadic;
514 else if (getCurFunctionDecl()) {
Douglas Gregor72564e72009-02-26 23:50:07 +0000515 if (FunctionProtoType* FTP =
516 dyn_cast<FunctionProtoType>(getCurFunctionDecl()->getType()))
Eli Friedman56f20ae2008-12-15 22:05:35 +0000517 isVariadic = FTP->isVariadic();
518 else
519 isVariadic = false;
520 } else {
Argyrios Kyrtzidis53d0ea52008-06-28 06:07:14 +0000521 isVariadic = getCurMethodDecl()->isVariadic();
Eli Friedman56f20ae2008-12-15 22:05:35 +0000522 }
Mike Stump1eb44332009-09-09 15:08:12 +0000523
Chris Lattnerc27c6652007-12-20 00:05:45 +0000524 if (!isVariadic) {
Chris Lattner30ce3442007-12-19 23:59:04 +0000525 Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function);
526 return true;
527 }
Mike Stump1eb44332009-09-09 15:08:12 +0000528
Chris Lattner30ce3442007-12-19 23:59:04 +0000529 // Verify that the second argument to the builtin is the last argument of the
530 // current function or method.
531 bool SecondArgIsLastNamedArgument = false;
Anders Carlssone2c14102008-02-13 01:22:59 +0000532 const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts();
Mike Stump1eb44332009-09-09 15:08:12 +0000533
Anders Carlsson88cf2262008-02-11 04:20:54 +0000534 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) {
535 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) {
Chris Lattner30ce3442007-12-19 23:59:04 +0000536 // FIXME: This isn't correct for methods (results in bogus warning).
537 // Get the last formal in the current function.
Anders Carlsson88cf2262008-02-11 04:20:54 +0000538 const ParmVarDecl *LastArg;
Steve Naroffcd9c5142009-04-15 19:33:47 +0000539 if (CurBlock)
540 LastArg = *(CurBlock->TheDecl->param_end()-1);
541 else if (FunctionDecl *FD = getCurFunctionDecl())
Chris Lattner371f2582008-12-04 23:50:19 +0000542 LastArg = *(FD->param_end()-1);
Chris Lattner30ce3442007-12-19 23:59:04 +0000543 else
Argyrios Kyrtzidis53d0ea52008-06-28 06:07:14 +0000544 LastArg = *(getCurMethodDecl()->param_end()-1);
Chris Lattner30ce3442007-12-19 23:59:04 +0000545 SecondArgIsLastNamedArgument = PV == LastArg;
546 }
547 }
Mike Stump1eb44332009-09-09 15:08:12 +0000548
Chris Lattner30ce3442007-12-19 23:59:04 +0000549 if (!SecondArgIsLastNamedArgument)
Mike Stump1eb44332009-09-09 15:08:12 +0000550 Diag(TheCall->getArg(1)->getLocStart(),
Chris Lattner30ce3442007-12-19 23:59:04 +0000551 diag::warn_second_parameter_of_va_start_not_last_named_argument);
552 return false;
Eli Friedman6cfda232008-05-20 08:23:37 +0000553}
Chris Lattner30ce3442007-12-19 23:59:04 +0000554
Chris Lattner1b9a0792007-12-20 00:26:33 +0000555/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and
556/// friends. This is declared to take (...), so we have to check everything.
Chris Lattner925e60d2007-12-28 05:29:59 +0000557bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) {
558 if (TheCall->getNumArgs() < 2)
Chris Lattner2c21a072008-11-21 18:44:24 +0000559 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
Eric Christopherd77b9a22010-04-16 04:48:22 +0000560 << 0 << 2 << TheCall->getNumArgs()/*function call*/;
Chris Lattner925e60d2007-12-28 05:29:59 +0000561 if (TheCall->getNumArgs() > 2)
Mike Stump1eb44332009-09-09 15:08:12 +0000562 return Diag(TheCall->getArg(2)->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000563 diag::err_typecheck_call_too_many_args)
Eric Christopherccfa9632010-04-16 04:56:46 +0000564 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000565 << SourceRange(TheCall->getArg(2)->getLocStart(),
566 (*(TheCall->arg_end()-1))->getLocEnd());
Mike Stump1eb44332009-09-09 15:08:12 +0000567
Chris Lattner925e60d2007-12-28 05:29:59 +0000568 Expr *OrigArg0 = TheCall->getArg(0);
569 Expr *OrigArg1 = TheCall->getArg(1);
Douglas Gregorcde01732009-05-19 22:10:17 +0000570
Chris Lattner1b9a0792007-12-20 00:26:33 +0000571 // Do standard promotions between the two arguments, returning their common
572 // type.
Chris Lattner925e60d2007-12-28 05:29:59 +0000573 QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false);
Daniel Dunbar403bc2b2009-02-19 19:28:43 +0000574
575 // Make sure any conversions are pushed back into the call; this is
576 // type safe since unordered compare builtins are declared as "_Bool
577 // foo(...)".
578 TheCall->setArg(0, OrigArg0);
579 TheCall->setArg(1, OrigArg1);
Mike Stump1eb44332009-09-09 15:08:12 +0000580
Douglas Gregorcde01732009-05-19 22:10:17 +0000581 if (OrigArg0->isTypeDependent() || OrigArg1->isTypeDependent())
582 return false;
583
Chris Lattner1b9a0792007-12-20 00:26:33 +0000584 // If the common type isn't a real floating type, then the arguments were
585 // invalid for this operation.
586 if (!Res->isRealFloatingType())
Mike Stump1eb44332009-09-09 15:08:12 +0000587 return Diag(OrigArg0->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000588 diag::err_typecheck_call_invalid_ordered_compare)
Chris Lattnerd1625842008-11-24 06:25:27 +0000589 << OrigArg0->getType() << OrigArg1->getType()
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000590 << SourceRange(OrigArg0->getLocStart(), OrigArg1->getLocEnd());
Mike Stump1eb44332009-09-09 15:08:12 +0000591
Chris Lattner1b9a0792007-12-20 00:26:33 +0000592 return false;
593}
594
Benjamin Kramere771a7a2010-02-15 22:42:31 +0000595/// SemaBuiltinSemaBuiltinFPClassification - Handle functions like
596/// __builtin_isnan and friends. This is declared to take (...), so we have
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000597/// to check everything. We expect the last argument to be a floating point
598/// value.
599bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) {
600 if (TheCall->getNumArgs() < NumArgs)
Eli Friedman9ac6f622009-08-31 20:06:00 +0000601 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
Eric Christopherd77b9a22010-04-16 04:48:22 +0000602 << 0 << NumArgs << TheCall->getNumArgs()/*function call*/;
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000603 if (TheCall->getNumArgs() > NumArgs)
604 return Diag(TheCall->getArg(NumArgs)->getLocStart(),
Eli Friedman9ac6f622009-08-31 20:06:00 +0000605 diag::err_typecheck_call_too_many_args)
Eric Christopherccfa9632010-04-16 04:56:46 +0000606 << 0 /*function call*/ << NumArgs << TheCall->getNumArgs()
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000607 << SourceRange(TheCall->getArg(NumArgs)->getLocStart(),
Eli Friedman9ac6f622009-08-31 20:06:00 +0000608 (*(TheCall->arg_end()-1))->getLocEnd());
609
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000610 Expr *OrigArg = TheCall->getArg(NumArgs-1);
Mike Stump1eb44332009-09-09 15:08:12 +0000611
Eli Friedman9ac6f622009-08-31 20:06:00 +0000612 if (OrigArg->isTypeDependent())
613 return false;
614
615 // This operation requires a floating-point number
616 if (!OrigArg->getType()->isRealFloatingType())
Mike Stump1eb44332009-09-09 15:08:12 +0000617 return Diag(OrigArg->getLocStart(),
Eli Friedman9ac6f622009-08-31 20:06:00 +0000618 diag::err_typecheck_call_invalid_unary_fp)
619 << OrigArg->getType() << OrigArg->getSourceRange();
Mike Stump1eb44332009-09-09 15:08:12 +0000620
Eli Friedman9ac6f622009-08-31 20:06:00 +0000621 return false;
622}
623
Eli Friedmand38617c2008-05-14 19:38:39 +0000624/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector.
625// This is declared to take (...), so we have to check everything.
Sebastian Redl0eb23302009-01-19 00:08:26 +0000626Action::OwningExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) {
Eli Friedmand38617c2008-05-14 19:38:39 +0000627 if (TheCall->getNumArgs() < 3)
Sebastian Redl0eb23302009-01-19 00:08:26 +0000628 return ExprError(Diag(TheCall->getLocEnd(),
Eric Christopherd77b9a22010-04-16 04:48:22 +0000629 diag::err_typecheck_call_too_few_args_at_least)
630 << 0 /*function call*/ << 3 << TheCall->getNumArgs()
631 << TheCall->getSourceRange());
Eli Friedmand38617c2008-05-14 19:38:39 +0000632
Douglas Gregorcde01732009-05-19 22:10:17 +0000633 unsigned numElements = std::numeric_limits<unsigned>::max();
634 if (!TheCall->getArg(0)->isTypeDependent() &&
635 !TheCall->getArg(1)->isTypeDependent()) {
636 QualType FAType = TheCall->getArg(0)->getType();
637 QualType SAType = TheCall->getArg(1)->getType();
Mike Stump1eb44332009-09-09 15:08:12 +0000638
Douglas Gregorcde01732009-05-19 22:10:17 +0000639 if (!FAType->isVectorType() || !SAType->isVectorType()) {
640 Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector)
Mike Stump1eb44332009-09-09 15:08:12 +0000641 << SourceRange(TheCall->getArg(0)->getLocStart(),
Douglas Gregorcde01732009-05-19 22:10:17 +0000642 TheCall->getArg(1)->getLocEnd());
643 return ExprError();
644 }
Mike Stump1eb44332009-09-09 15:08:12 +0000645
Douglas Gregora4923eb2009-11-16 21:35:15 +0000646 if (!Context.hasSameUnqualifiedType(FAType, SAType)) {
Douglas Gregorcde01732009-05-19 22:10:17 +0000647 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector)
Mike Stump1eb44332009-09-09 15:08:12 +0000648 << SourceRange(TheCall->getArg(0)->getLocStart(),
Douglas Gregorcde01732009-05-19 22:10:17 +0000649 TheCall->getArg(1)->getLocEnd());
650 return ExprError();
651 }
Eli Friedmand38617c2008-05-14 19:38:39 +0000652
John McCall183700f2009-09-21 23:43:11 +0000653 numElements = FAType->getAs<VectorType>()->getNumElements();
Douglas Gregorcde01732009-05-19 22:10:17 +0000654 if (TheCall->getNumArgs() != numElements+2) {
655 if (TheCall->getNumArgs() < numElements+2)
656 return ExprError(Diag(TheCall->getLocEnd(),
657 diag::err_typecheck_call_too_few_args)
Eric Christopherd77b9a22010-04-16 04:48:22 +0000658 << 0 /*function call*/
659 << numElements+2 << TheCall->getNumArgs()
660 << TheCall->getSourceRange());
Sebastian Redl0eb23302009-01-19 00:08:26 +0000661 return ExprError(Diag(TheCall->getLocEnd(),
Douglas Gregorcde01732009-05-19 22:10:17 +0000662 diag::err_typecheck_call_too_many_args)
Eric Christopherccfa9632010-04-16 04:56:46 +0000663 << 0 /*function call*/
664 << numElements+2 << TheCall->getNumArgs()
665 << TheCall->getSourceRange());
Douglas Gregorcde01732009-05-19 22:10:17 +0000666 }
Eli Friedmand38617c2008-05-14 19:38:39 +0000667 }
668
669 for (unsigned i = 2; i < TheCall->getNumArgs(); i++) {
Douglas Gregorcde01732009-05-19 22:10:17 +0000670 if (TheCall->getArg(i)->isTypeDependent() ||
671 TheCall->getArg(i)->isValueDependent())
672 continue;
673
Eric Christopher691ebc32010-04-17 02:26:23 +0000674 llvm::APSInt Result;
675 if (SemaBuiltinConstantArg(TheCall, i, Result))
676 return ExprError();
Sebastian Redl0eb23302009-01-19 00:08:26 +0000677
Chris Lattnerd1a0b6d2008-08-10 02:05:13 +0000678 if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2)
Sebastian Redl0eb23302009-01-19 00:08:26 +0000679 return ExprError(Diag(TheCall->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000680 diag::err_shufflevector_argument_too_large)
Sebastian Redl0eb23302009-01-19 00:08:26 +0000681 << TheCall->getArg(i)->getSourceRange());
Eli Friedmand38617c2008-05-14 19:38:39 +0000682 }
683
684 llvm::SmallVector<Expr*, 32> exprs;
685
Chris Lattnerd1a0b6d2008-08-10 02:05:13 +0000686 for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) {
Eli Friedmand38617c2008-05-14 19:38:39 +0000687 exprs.push_back(TheCall->getArg(i));
688 TheCall->setArg(i, 0);
689 }
690
Nate Begemana88dc302009-08-12 02:10:25 +0000691 return Owned(new (Context) ShuffleVectorExpr(Context, exprs.begin(),
692 exprs.size(), exprs[0]->getType(),
Ted Kremenek8189cde2009-02-07 01:47:29 +0000693 TheCall->getCallee()->getLocStart(),
694 TheCall->getRParenLoc()));
Eli Friedmand38617c2008-05-14 19:38:39 +0000695}
Chris Lattner30ce3442007-12-19 23:59:04 +0000696
Daniel Dunbar4493f792008-07-21 22:59:13 +0000697/// SemaBuiltinPrefetch - Handle __builtin_prefetch.
698// This is declared to take (const void*, ...) and can take two
699// optional constant int args.
700bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) {
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000701 unsigned NumArgs = TheCall->getNumArgs();
Daniel Dunbar4493f792008-07-21 22:59:13 +0000702
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000703 if (NumArgs > 3)
Eric Christopherccfa9632010-04-16 04:56:46 +0000704 return Diag(TheCall->getLocEnd(),
705 diag::err_typecheck_call_too_many_args_at_most)
706 << 0 /*function call*/ << 3 << NumArgs
707 << TheCall->getSourceRange();
Daniel Dunbar4493f792008-07-21 22:59:13 +0000708
709 // Argument 0 is checked for us and the remaining arguments must be
710 // constant integers.
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000711 for (unsigned i = 1; i != NumArgs; ++i) {
Daniel Dunbar4493f792008-07-21 22:59:13 +0000712 Expr *Arg = TheCall->getArg(i);
Eric Christopher691ebc32010-04-17 02:26:23 +0000713
Eli Friedman9aef7262009-12-04 00:30:06 +0000714 llvm::APSInt Result;
Eric Christopher691ebc32010-04-17 02:26:23 +0000715 if (SemaBuiltinConstantArg(TheCall, i, Result))
716 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000717
Daniel Dunbar4493f792008-07-21 22:59:13 +0000718 // FIXME: gcc issues a warning and rewrites these to 0. These
719 // seems especially odd for the third argument since the default
720 // is 3.
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000721 if (i == 1) {
Eli Friedman9aef7262009-12-04 00:30:06 +0000722 if (Result.getLimitedValue() > 1)
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000723 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
Chris Lattner21fb98e2009-09-23 06:06:36 +0000724 << "0" << "1" << Arg->getSourceRange();
Daniel Dunbar4493f792008-07-21 22:59:13 +0000725 } else {
Eli Friedman9aef7262009-12-04 00:30:06 +0000726 if (Result.getLimitedValue() > 3)
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000727 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
Chris Lattner21fb98e2009-09-23 06:06:36 +0000728 << "0" << "3" << Arg->getSourceRange();
Daniel Dunbar4493f792008-07-21 22:59:13 +0000729 }
730 }
731
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000732 return false;
Daniel Dunbar4493f792008-07-21 22:59:13 +0000733}
734
Eric Christopher691ebc32010-04-17 02:26:23 +0000735/// SemaBuiltinConstantArg - Handle a check if argument ArgNum of CallExpr
736/// TheCall is a constant expression.
737bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
738 llvm::APSInt &Result) {
739 Expr *Arg = TheCall->getArg(ArgNum);
740 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
741 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
742
743 if (Arg->isTypeDependent() || Arg->isValueDependent()) return false;
744
745 if (!Arg->isIntegerConstantExpr(Result, Context))
746 return Diag(TheCall->getLocStart(), diag::err_constant_integer_arg_type)
Eric Christopher5e896552010-04-19 18:23:02 +0000747 << FDecl->getDeclName() << Arg->getSourceRange();
Eric Christopher691ebc32010-04-17 02:26:23 +0000748
Chris Lattner21fb98e2009-09-23 06:06:36 +0000749 return false;
750}
751
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000752/// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr,
753/// int type). This simply type checks that type is one of the defined
754/// constants (0-3).
Eric Christopherfee667f2009-12-23 03:49:37 +0000755// For compatability check 0-3, llvm only handles 0 and 2.
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000756bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) {
Eric Christopher691ebc32010-04-17 02:26:23 +0000757 llvm::APSInt Result;
758
759 // Check constant-ness first.
760 if (SemaBuiltinConstantArg(TheCall, 1, Result))
761 return true;
762
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000763 Expr *Arg = TheCall->getArg(1);
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000764 if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) {
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000765 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
766 << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000767 }
768
769 return false;
770}
771
Eli Friedman586d6a82009-05-03 06:04:26 +0000772/// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val).
Eli Friedmand875fed2009-05-03 04:46:36 +0000773/// This checks that val is a constant 1.
774bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) {
775 Expr *Arg = TheCall->getArg(1);
Eric Christopher691ebc32010-04-17 02:26:23 +0000776 llvm::APSInt Result;
Douglas Gregorcde01732009-05-19 22:10:17 +0000777
Eric Christopher691ebc32010-04-17 02:26:23 +0000778 // TODO: This is less than ideal. Overload this to take a value.
779 if (SemaBuiltinConstantArg(TheCall, 1, Result))
780 return true;
781
782 if (Result != 1)
Eli Friedmand875fed2009-05-03 04:46:36 +0000783 return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val)
784 << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
785
786 return false;
787}
788
Ted Kremenekd30ef872009-01-12 23:09:09 +0000789// Handle i > 1 ? "x" : "y", recursivelly
Ted Kremenek082d9362009-03-20 21:35:28 +0000790bool Sema::SemaCheckStringLiteral(const Expr *E, const CallExpr *TheCall,
791 bool HasVAListArg,
Douglas Gregor3c385e52009-02-14 18:57:46 +0000792 unsigned format_idx, unsigned firstDataArg) {
Douglas Gregorcde01732009-05-19 22:10:17 +0000793 if (E->isTypeDependent() || E->isValueDependent())
794 return false;
Ted Kremenekd30ef872009-01-12 23:09:09 +0000795
796 switch (E->getStmtClass()) {
797 case Stmt::ConditionalOperatorClass: {
Ted Kremenek082d9362009-03-20 21:35:28 +0000798 const ConditionalOperator *C = cast<ConditionalOperator>(E);
Chris Lattner813b70d2009-12-22 06:00:13 +0000799 return SemaCheckStringLiteral(C->getTrueExpr(), TheCall,
Douglas Gregor3c385e52009-02-14 18:57:46 +0000800 HasVAListArg, format_idx, firstDataArg)
Ted Kremenekd30ef872009-01-12 23:09:09 +0000801 && SemaCheckStringLiteral(C->getRHS(), TheCall,
Douglas Gregor3c385e52009-02-14 18:57:46 +0000802 HasVAListArg, format_idx, firstDataArg);
Ted Kremenekd30ef872009-01-12 23:09:09 +0000803 }
804
805 case Stmt::ImplicitCastExprClass: {
Ted Kremenek082d9362009-03-20 21:35:28 +0000806 const ImplicitCastExpr *Expr = cast<ImplicitCastExpr>(E);
Ted Kremenekd30ef872009-01-12 23:09:09 +0000807 return SemaCheckStringLiteral(Expr->getSubExpr(), TheCall, HasVAListArg,
Douglas Gregor3c385e52009-02-14 18:57:46 +0000808 format_idx, firstDataArg);
Ted Kremenekd30ef872009-01-12 23:09:09 +0000809 }
810
811 case Stmt::ParenExprClass: {
Ted Kremenek082d9362009-03-20 21:35:28 +0000812 const ParenExpr *Expr = cast<ParenExpr>(E);
Ted Kremenekd30ef872009-01-12 23:09:09 +0000813 return SemaCheckStringLiteral(Expr->getSubExpr(), TheCall, HasVAListArg,
Douglas Gregor3c385e52009-02-14 18:57:46 +0000814 format_idx, firstDataArg);
Ted Kremenekd30ef872009-01-12 23:09:09 +0000815 }
Mike Stump1eb44332009-09-09 15:08:12 +0000816
Ted Kremenek082d9362009-03-20 21:35:28 +0000817 case Stmt::DeclRefExprClass: {
818 const DeclRefExpr *DR = cast<DeclRefExpr>(E);
Mike Stump1eb44332009-09-09 15:08:12 +0000819
Ted Kremenek082d9362009-03-20 21:35:28 +0000820 // As an exception, do not flag errors for variables binding to
821 // const string literals.
822 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
823 bool isConstant = false;
824 QualType T = DR->getType();
Ted Kremenekd30ef872009-01-12 23:09:09 +0000825
Ted Kremenek082d9362009-03-20 21:35:28 +0000826 if (const ArrayType *AT = Context.getAsArrayType(T)) {
827 isConstant = AT->getElementType().isConstant(Context);
Mike Stumpac5fc7c2009-08-04 21:02:39 +0000828 } else if (const PointerType *PT = T->getAs<PointerType>()) {
Mike Stump1eb44332009-09-09 15:08:12 +0000829 isConstant = T.isConstant(Context) &&
Ted Kremenek082d9362009-03-20 21:35:28 +0000830 PT->getPointeeType().isConstant(Context);
831 }
Mike Stump1eb44332009-09-09 15:08:12 +0000832
Ted Kremenek082d9362009-03-20 21:35:28 +0000833 if (isConstant) {
Sebastian Redl31310a22010-02-01 20:16:42 +0000834 if (const Expr *Init = VD->getAnyInitializer())
Ted Kremenek082d9362009-03-20 21:35:28 +0000835 return SemaCheckStringLiteral(Init, TheCall,
836 HasVAListArg, format_idx, firstDataArg);
837 }
Mike Stump1eb44332009-09-09 15:08:12 +0000838
Anders Carlssond966a552009-06-28 19:55:58 +0000839 // For vprintf* functions (i.e., HasVAListArg==true), we add a
840 // special check to see if the format string is a function parameter
841 // of the function calling the printf function. If the function
842 // has an attribute indicating it is a printf-like function, then we
843 // should suppress warnings concerning non-literals being used in a call
844 // to a vprintf function. For example:
845 //
846 // void
847 // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){
848 // va_list ap;
849 // va_start(ap, fmt);
850 // vprintf(fmt, ap); // Do NOT emit a warning about "fmt".
851 // ...
852 //
853 //
854 // FIXME: We don't have full attribute support yet, so just check to see
855 // if the argument is a DeclRefExpr that references a parameter. We'll
856 // add proper support for checking the attribute later.
857 if (HasVAListArg)
858 if (isa<ParmVarDecl>(VD))
859 return true;
Ted Kremenek082d9362009-03-20 21:35:28 +0000860 }
Mike Stump1eb44332009-09-09 15:08:12 +0000861
Ted Kremenek082d9362009-03-20 21:35:28 +0000862 return false;
863 }
Ted Kremenekd30ef872009-01-12 23:09:09 +0000864
Anders Carlsson8f031b32009-06-27 04:05:33 +0000865 case Stmt::CallExprClass: {
866 const CallExpr *CE = cast<CallExpr>(E);
Mike Stump1eb44332009-09-09 15:08:12 +0000867 if (const ImplicitCastExpr *ICE
Anders Carlsson8f031b32009-06-27 04:05:33 +0000868 = dyn_cast<ImplicitCastExpr>(CE->getCallee())) {
869 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
870 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
Argyrios Kyrtzidis40b598e2009-06-30 02:34:44 +0000871 if (const FormatArgAttr *FA = FD->getAttr<FormatArgAttr>()) {
Anders Carlsson8f031b32009-06-27 04:05:33 +0000872 unsigned ArgIndex = FA->getFormatIdx();
873 const Expr *Arg = CE->getArg(ArgIndex - 1);
Mike Stump1eb44332009-09-09 15:08:12 +0000874
875 return SemaCheckStringLiteral(Arg, TheCall, HasVAListArg,
Anders Carlsson8f031b32009-06-27 04:05:33 +0000876 format_idx, firstDataArg);
877 }
878 }
879 }
880 }
Mike Stump1eb44332009-09-09 15:08:12 +0000881
Anders Carlsson8f031b32009-06-27 04:05:33 +0000882 return false;
883 }
Ted Kremenek082d9362009-03-20 21:35:28 +0000884 case Stmt::ObjCStringLiteralClass:
885 case Stmt::StringLiteralClass: {
886 const StringLiteral *StrE = NULL;
Mike Stump1eb44332009-09-09 15:08:12 +0000887
Ted Kremenek082d9362009-03-20 21:35:28 +0000888 if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E))
Ted Kremenekd30ef872009-01-12 23:09:09 +0000889 StrE = ObjCFExpr->getString();
890 else
Ted Kremenek082d9362009-03-20 21:35:28 +0000891 StrE = cast<StringLiteral>(E);
Mike Stump1eb44332009-09-09 15:08:12 +0000892
Ted Kremenekd30ef872009-01-12 23:09:09 +0000893 if (StrE) {
Mike Stump1eb44332009-09-09 15:08:12 +0000894 CheckPrintfString(StrE, E, TheCall, HasVAListArg, format_idx,
Douglas Gregor3c385e52009-02-14 18:57:46 +0000895 firstDataArg);
Ted Kremenekd30ef872009-01-12 23:09:09 +0000896 return true;
897 }
Mike Stump1eb44332009-09-09 15:08:12 +0000898
Ted Kremenekd30ef872009-01-12 23:09:09 +0000899 return false;
900 }
Mike Stump1eb44332009-09-09 15:08:12 +0000901
Ted Kremenek082d9362009-03-20 21:35:28 +0000902 default:
903 return false;
Ted Kremenekd30ef872009-01-12 23:09:09 +0000904 }
905}
906
Fariborz Jahaniane898f8a2009-05-21 18:48:51 +0000907void
Mike Stump1eb44332009-09-09 15:08:12 +0000908Sema::CheckNonNullArguments(const NonNullAttr *NonNull,
909 const CallExpr *TheCall) {
Fariborz Jahaniane898f8a2009-05-21 18:48:51 +0000910 for (NonNullAttr::iterator i = NonNull->begin(), e = NonNull->end();
911 i != e; ++i) {
Chris Lattner12b97ff2009-05-25 18:23:36 +0000912 const Expr *ArgExpr = TheCall->getArg(*i);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +0000913 if (ArgExpr->isNullPointerConstant(Context,
Douglas Gregorce940492009-09-25 04:25:58 +0000914 Expr::NPC_ValueDependentIsNotNull))
Chris Lattner12b97ff2009-05-25 18:23:36 +0000915 Diag(TheCall->getCallee()->getLocStart(), diag::warn_null_arg)
916 << ArgExpr->getSourceRange();
Fariborz Jahaniane898f8a2009-05-21 18:48:51 +0000917 }
918}
Ted Kremenekd30ef872009-01-12 23:09:09 +0000919
Chris Lattner59907c42007-08-10 20:18:51 +0000920/// CheckPrintfArguments - Check calls to printf (and similar functions) for
Mike Stump1eb44332009-09-09 15:08:12 +0000921/// correct use of format strings.
Ted Kremenek71895b92007-08-14 17:39:48 +0000922///
923/// HasVAListArg - A predicate indicating whether the printf-like
924/// function is passed an explicit va_arg argument (e.g., vprintf)
925///
926/// format_idx - The index into Args for the format string.
927///
928/// Improper format strings to functions in the printf family can be
929/// the source of bizarre bugs and very serious security holes. A
930/// good source of information is available in the following paper
931/// (which includes additional references):
Chris Lattner59907c42007-08-10 20:18:51 +0000932///
933/// FormatGuard: Automatic Protection From printf Format String
934/// Vulnerabilities, Proceedings of the 10th USENIX Security Symposium, 2001.
Ted Kremenek71895b92007-08-14 17:39:48 +0000935///
Ted Kremenek7f70dc82010-02-26 19:18:41 +0000936/// TODO:
Ted Kremenek71895b92007-08-14 17:39:48 +0000937/// Functionality implemented:
938///
939/// We can statically check the following properties for string
940/// literal format strings for non v.*printf functions (where the
941/// arguments are passed directly):
942//
943/// (1) Are the number of format conversions equal to the number of
944/// data arguments?
945///
946/// (2) Does each format conversion correctly match the type of the
Ted Kremenek7f70dc82010-02-26 19:18:41 +0000947/// corresponding data argument?
Ted Kremenek71895b92007-08-14 17:39:48 +0000948///
949/// Moreover, for all printf functions we can:
950///
951/// (3) Check for a missing format string (when not caught by type checking).
952///
953/// (4) Check for no-operation flags; e.g. using "#" with format
954/// conversion 'c' (TODO)
955///
956/// (5) Check the use of '%n', a major source of security holes.
957///
958/// (6) Check for malformed format conversions that don't specify anything.
959///
960/// (7) Check for empty format strings. e.g: printf("");
961///
962/// (8) Check that the format string is a wide literal.
963///
964/// All of these checks can be done by parsing the format string.
965///
Chris Lattner59907c42007-08-10 20:18:51 +0000966void
Mike Stump1eb44332009-09-09 15:08:12 +0000967Sema::CheckPrintfArguments(const CallExpr *TheCall, bool HasVAListArg,
Douglas Gregor3c385e52009-02-14 18:57:46 +0000968 unsigned format_idx, unsigned firstDataArg) {
Ted Kremenek082d9362009-03-20 21:35:28 +0000969 const Expr *Fn = TheCall->getCallee();
Chris Lattner925e60d2007-12-28 05:29:59 +0000970
Sebastian Redl4a2614e2009-11-17 18:02:24 +0000971 // The way the format attribute works in GCC, the implicit this argument
972 // of member functions is counted. However, it doesn't appear in our own
973 // lists, so decrement format_idx in that case.
974 if (isa<CXXMemberCallExpr>(TheCall)) {
975 // Catch a format attribute mistakenly referring to the object argument.
976 if (format_idx == 0)
977 return;
978 --format_idx;
979 if(firstDataArg != 0)
980 --firstDataArg;
981 }
982
Mike Stump1eb44332009-09-09 15:08:12 +0000983 // CHECK: printf-like function is called with no format string.
Chris Lattner925e60d2007-12-28 05:29:59 +0000984 if (format_idx >= TheCall->getNumArgs()) {
Chris Lattnerdcd5ef12008-11-19 05:27:50 +0000985 Diag(TheCall->getRParenLoc(), diag::warn_printf_missing_format_string)
986 << Fn->getSourceRange();
Ted Kremenek71895b92007-08-14 17:39:48 +0000987 return;
988 }
Mike Stump1eb44332009-09-09 15:08:12 +0000989
Ted Kremenek082d9362009-03-20 21:35:28 +0000990 const Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts();
Mike Stump1eb44332009-09-09 15:08:12 +0000991
Chris Lattner59907c42007-08-10 20:18:51 +0000992 // CHECK: format string is not a string literal.
Mike Stump1eb44332009-09-09 15:08:12 +0000993 //
Ted Kremenek71895b92007-08-14 17:39:48 +0000994 // Dynamically generated format strings are difficult to
995 // automatically vet at compile time. Requiring that format strings
996 // are string literals: (1) permits the checking of format strings by
997 // the compiler and thereby (2) can practically remove the source of
998 // many format string exploits.
Ted Kremenek7ff22b22008-06-16 18:00:42 +0000999
Mike Stump1eb44332009-09-09 15:08:12 +00001000 // Format string can be either ObjC string (e.g. @"%d") or
Ted Kremenek7ff22b22008-06-16 18:00:42 +00001001 // C string (e.g. "%d")
Mike Stump1eb44332009-09-09 15:08:12 +00001002 // ObjC string uses the same format specifiers as C string, so we can use
Ted Kremenek7ff22b22008-06-16 18:00:42 +00001003 // the same format string checking logic for both ObjC and C strings.
Chris Lattner1cd3e1f2009-04-29 04:49:34 +00001004 if (SemaCheckStringLiteral(OrigFormatExpr, TheCall, HasVAListArg, format_idx,
1005 firstDataArg))
1006 return; // Literal format string found, check done!
Ted Kremenek7ff22b22008-06-16 18:00:42 +00001007
Chris Lattner655f1412009-04-29 04:59:47 +00001008 // If there are no arguments specified, warn with -Wformat-security, otherwise
1009 // warn only with -Wformat-nonliteral.
1010 if (TheCall->getNumArgs() == format_idx+1)
Mike Stump1eb44332009-09-09 15:08:12 +00001011 Diag(TheCall->getArg(format_idx)->getLocStart(),
Chris Lattner655f1412009-04-29 04:59:47 +00001012 diag::warn_printf_nonliteral_noargs)
1013 << OrigFormatExpr->getSourceRange();
1014 else
Mike Stump1eb44332009-09-09 15:08:12 +00001015 Diag(TheCall->getArg(format_idx)->getLocStart(),
Chris Lattner655f1412009-04-29 04:59:47 +00001016 diag::warn_printf_nonliteral)
1017 << OrigFormatExpr->getSourceRange();
Ted Kremenekd30ef872009-01-12 23:09:09 +00001018}
Ted Kremenek71895b92007-08-14 17:39:48 +00001019
Ted Kremeneke0e53132010-01-28 23:39:18 +00001020namespace {
Ted Kremenek74d56a12010-02-04 20:46:58 +00001021class CheckPrintfHandler : public analyze_printf::FormatStringHandler {
Ted Kremeneke0e53132010-01-28 23:39:18 +00001022 Sema &S;
1023 const StringLiteral *FExpr;
1024 const Expr *OrigFormatExpr;
Ted Kremenek6ee76532010-03-25 03:59:12 +00001025 const unsigned FirstDataArg;
Ted Kremeneke0e53132010-01-28 23:39:18 +00001026 const unsigned NumDataArgs;
1027 const bool IsObjCLiteral;
1028 const char *Beg; // Start of format string.
Ted Kremenek0d277352010-01-29 01:06:55 +00001029 const bool HasVAListArg;
1030 const CallExpr *TheCall;
1031 unsigned FormatIdx;
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001032 llvm::BitVector CoveredArgs;
Ted Kremenekefaff192010-02-27 01:41:03 +00001033 bool usesPositionalArgs;
1034 bool atFirstArg;
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001035public:
Ted Kremeneke0e53132010-01-28 23:39:18 +00001036 CheckPrintfHandler(Sema &s, const StringLiteral *fexpr,
Ted Kremenek6ee76532010-03-25 03:59:12 +00001037 const Expr *origFormatExpr, unsigned firstDataArg,
Ted Kremeneke0e53132010-01-28 23:39:18 +00001038 unsigned numDataArgs, bool isObjCLiteral,
Ted Kremenek0d277352010-01-29 01:06:55 +00001039 const char *beg, bool hasVAListArg,
1040 const CallExpr *theCall, unsigned formatIdx)
Ted Kremeneke0e53132010-01-28 23:39:18 +00001041 : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr),
Ted Kremenek6ee76532010-03-25 03:59:12 +00001042 FirstDataArg(firstDataArg),
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001043 NumDataArgs(numDataArgs),
Ted Kremenek0d277352010-01-29 01:06:55 +00001044 IsObjCLiteral(isObjCLiteral), Beg(beg),
1045 HasVAListArg(hasVAListArg),
Ted Kremenekefaff192010-02-27 01:41:03 +00001046 TheCall(theCall), FormatIdx(formatIdx),
1047 usesPositionalArgs(false), atFirstArg(true) {
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001048 CoveredArgs.resize(numDataArgs);
1049 CoveredArgs.reset();
1050 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001051
Ted Kremenek07d161f2010-01-29 01:50:07 +00001052 void DoneProcessing();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001053
Ted Kremenek808015a2010-01-29 03:16:21 +00001054 void HandleIncompleteFormatSpecifier(const char *startSpecifier,
1055 unsigned specifierLen);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001056
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001057 bool
Ted Kremenek74d56a12010-02-04 20:46:58 +00001058 HandleInvalidConversionSpecifier(const analyze_printf::FormatSpecifier &FS,
1059 const char *startSpecifier,
1060 unsigned specifierLen);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001061
Ted Kremenekefaff192010-02-27 01:41:03 +00001062 virtual void HandleInvalidPosition(const char *startSpecifier,
1063 unsigned specifierLen,
1064 analyze_printf::PositionContext p);
1065
1066 virtual void HandleZeroPosition(const char *startPos, unsigned posLen);
1067
Ted Kremeneke0e53132010-01-28 23:39:18 +00001068 void HandleNullChar(const char *nullCharacter);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001069
Ted Kremeneke0e53132010-01-28 23:39:18 +00001070 bool HandleFormatSpecifier(const analyze_printf::FormatSpecifier &FS,
1071 const char *startSpecifier,
1072 unsigned specifierLen);
1073private:
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001074 SourceRange getFormatStringRange();
1075 SourceRange getFormatSpecifierRange(const char *startSpecifier,
Ted Kremenek0e5675d2010-02-10 02:16:30 +00001076 unsigned specifierLen);
Ted Kremeneke0e53132010-01-28 23:39:18 +00001077 SourceLocation getLocationOfByte(const char *x);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001078
Ted Kremenekefaff192010-02-27 01:41:03 +00001079 bool HandleAmount(const analyze_printf::OptionalAmount &Amt, unsigned k,
1080 const char *startSpecifier, unsigned specifierLen);
Ted Kremenek5c41ee82010-02-11 09:27:41 +00001081 void HandleFlags(const analyze_printf::FormatSpecifier &FS,
1082 llvm::StringRef flag, llvm::StringRef cspec,
1083 const char *startSpecifier, unsigned specifierLen);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001084
Ted Kremenek0d277352010-01-29 01:06:55 +00001085 const Expr *getDataArg(unsigned i) const;
Ted Kremeneke0e53132010-01-28 23:39:18 +00001086};
1087}
1088
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001089SourceRange CheckPrintfHandler::getFormatStringRange() {
Ted Kremeneke0e53132010-01-28 23:39:18 +00001090 return OrigFormatExpr->getSourceRange();
1091}
1092
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001093SourceRange CheckPrintfHandler::
1094getFormatSpecifierRange(const char *startSpecifier, unsigned specifierLen) {
1095 return SourceRange(getLocationOfByte(startSpecifier),
Ted Kremenek0e5675d2010-02-10 02:16:30 +00001096 getLocationOfByte(startSpecifier+specifierLen-1));
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001097}
1098
Ted Kremeneke0e53132010-01-28 23:39:18 +00001099SourceLocation CheckPrintfHandler::getLocationOfByte(const char *x) {
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001100 return S.getLocationOfStringLiteralByte(FExpr, x - Beg);
Ted Kremeneke0e53132010-01-28 23:39:18 +00001101}
1102
Ted Kremenek26ac2e02010-01-29 02:40:24 +00001103void CheckPrintfHandler::
Ted Kremenek808015a2010-01-29 03:16:21 +00001104HandleIncompleteFormatSpecifier(const char *startSpecifier,
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001105 unsigned specifierLen) {
Ted Kremenek808015a2010-01-29 03:16:21 +00001106 SourceLocation Loc = getLocationOfByte(startSpecifier);
1107 S.Diag(Loc, diag::warn_printf_incomplete_specifier)
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001108 << getFormatSpecifierRange(startSpecifier, specifierLen);
Ted Kremenek808015a2010-01-29 03:16:21 +00001109}
1110
Ted Kremenekefaff192010-02-27 01:41:03 +00001111void
1112CheckPrintfHandler::HandleInvalidPosition(const char *startPos, unsigned posLen,
1113 analyze_printf::PositionContext p) {
1114 SourceLocation Loc = getLocationOfByte(startPos);
1115 S.Diag(Loc, diag::warn_printf_invalid_positional_specifier)
1116 << (unsigned) p << getFormatSpecifierRange(startPos, posLen);
1117}
1118
1119void CheckPrintfHandler::HandleZeroPosition(const char *startPos,
1120 unsigned posLen) {
1121 SourceLocation Loc = getLocationOfByte(startPos);
1122 S.Diag(Loc, diag::warn_printf_zero_positional_specifier)
1123 << getFormatSpecifierRange(startPos, posLen);
1124}
1125
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001126bool CheckPrintfHandler::
Ted Kremenek26ac2e02010-01-29 02:40:24 +00001127HandleInvalidConversionSpecifier(const analyze_printf::FormatSpecifier &FS,
1128 const char *startSpecifier,
1129 unsigned specifierLen) {
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001130
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001131 unsigned argIndex = FS.getArgIndex();
1132 bool keepGoing = true;
1133 if (argIndex < NumDataArgs) {
1134 // Consider the argument coverered, even though the specifier doesn't
1135 // make sense.
1136 CoveredArgs.set(argIndex);
1137 }
1138 else {
1139 // If argIndex exceeds the number of data arguments we
1140 // don't issue a warning because that is just a cascade of warnings (and
1141 // they may have intended '%%' anyway). We don't want to continue processing
1142 // the format string after this point, however, as we will like just get
1143 // gibberish when trying to match arguments.
1144 keepGoing = false;
1145 }
1146
Ted Kremenek808015a2010-01-29 03:16:21 +00001147 const analyze_printf::ConversionSpecifier &CS =
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001148 FS.getConversionSpecifier();
Ted Kremenek808015a2010-01-29 03:16:21 +00001149 SourceLocation Loc = getLocationOfByte(CS.getStart());
Ted Kremenek26ac2e02010-01-29 02:40:24 +00001150 S.Diag(Loc, diag::warn_printf_invalid_conversion)
Ted Kremenek808015a2010-01-29 03:16:21 +00001151 << llvm::StringRef(CS.getStart(), CS.getLength())
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001152 << getFormatSpecifierRange(startSpecifier, specifierLen);
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001153
1154 return keepGoing;
Ted Kremenek26ac2e02010-01-29 02:40:24 +00001155}
1156
Ted Kremeneke0e53132010-01-28 23:39:18 +00001157void CheckPrintfHandler::HandleNullChar(const char *nullCharacter) {
1158 // The presence of a null character is likely an error.
1159 S.Diag(getLocationOfByte(nullCharacter),
1160 diag::warn_printf_format_string_contains_null_char)
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001161 << getFormatStringRange();
Ted Kremeneke0e53132010-01-28 23:39:18 +00001162}
1163
Ted Kremenek0d277352010-01-29 01:06:55 +00001164const Expr *CheckPrintfHandler::getDataArg(unsigned i) const {
Ted Kremenek6ee76532010-03-25 03:59:12 +00001165 return TheCall->getArg(FirstDataArg + i);
Ted Kremenek0d277352010-01-29 01:06:55 +00001166}
1167
Ted Kremenek5c41ee82010-02-11 09:27:41 +00001168void CheckPrintfHandler::HandleFlags(const analyze_printf::FormatSpecifier &FS,
1169 llvm::StringRef flag,
1170 llvm::StringRef cspec,
1171 const char *startSpecifier,
1172 unsigned specifierLen) {
1173 const analyze_printf::ConversionSpecifier &CS = FS.getConversionSpecifier();
1174 S.Diag(getLocationOfByte(CS.getStart()), diag::warn_printf_nonsensical_flag)
1175 << flag << cspec << getFormatSpecifierRange(startSpecifier, specifierLen);
1176}
1177
Ted Kremenek0d277352010-01-29 01:06:55 +00001178bool
1179CheckPrintfHandler::HandleAmount(const analyze_printf::OptionalAmount &Amt,
Ted Kremenekefaff192010-02-27 01:41:03 +00001180 unsigned k, const char *startSpecifier,
Ted Kremenek0e5675d2010-02-10 02:16:30 +00001181 unsigned specifierLen) {
Ted Kremenek0d277352010-01-29 01:06:55 +00001182
1183 if (Amt.hasDataArgument()) {
Ted Kremenek0d277352010-01-29 01:06:55 +00001184 if (!HasVAListArg) {
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001185 unsigned argIndex = Amt.getArgIndex();
1186 if (argIndex >= NumDataArgs) {
Ted Kremenekefaff192010-02-27 01:41:03 +00001187 S.Diag(getLocationOfByte(Amt.getStart()),
1188 diag::warn_printf_asterisk_missing_arg)
1189 << k << getFormatSpecifierRange(startSpecifier, specifierLen);
Ted Kremenek0d277352010-01-29 01:06:55 +00001190 // Don't do any more checking. We will just emit
1191 // spurious errors.
1192 return false;
1193 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001194
Ted Kremenek0d277352010-01-29 01:06:55 +00001195 // Type check the data argument. It should be an 'int'.
Ted Kremenek31f8e322010-01-29 23:32:22 +00001196 // Although not in conformance with C99, we also allow the argument to be
1197 // an 'unsigned int' as that is a reasonably safe case. GCC also
1198 // doesn't emit a warning for that case.
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001199 CoveredArgs.set(argIndex);
1200 const Expr *Arg = getDataArg(argIndex);
Ted Kremenek0d277352010-01-29 01:06:55 +00001201 QualType T = Arg->getType();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001202
1203 const analyze_printf::ArgTypeResult &ATR = Amt.getArgType(S.Context);
1204 assert(ATR.isValid());
1205
1206 if (!ATR.matchesType(S.Context, T)) {
Ted Kremenekefaff192010-02-27 01:41:03 +00001207 S.Diag(getLocationOfByte(Amt.getStart()),
1208 diag::warn_printf_asterisk_wrong_type)
1209 << k
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001210 << ATR.getRepresentativeType(S.Context) << T
Ted Kremenekd635c5f2010-01-30 00:49:51 +00001211 << getFormatSpecifierRange(startSpecifier, specifierLen)
1212 << Arg->getSourceRange();
Ted Kremenek0d277352010-01-29 01:06:55 +00001213 // Don't do any more checking. We will just emit
1214 // spurious errors.
1215 return false;
1216 }
1217 }
1218 }
1219 return true;
1220}
Ted Kremenek0d277352010-01-29 01:06:55 +00001221
Ted Kremeneke0e53132010-01-28 23:39:18 +00001222bool
Ted Kremenek5c41ee82010-02-11 09:27:41 +00001223CheckPrintfHandler::HandleFormatSpecifier(const analyze_printf::FormatSpecifier
1224 &FS,
Ted Kremeneke0e53132010-01-28 23:39:18 +00001225 const char *startSpecifier,
1226 unsigned specifierLen) {
1227
Ted Kremenekefaff192010-02-27 01:41:03 +00001228 using namespace analyze_printf;
Ted Kremeneke0e53132010-01-28 23:39:18 +00001229 const ConversionSpecifier &CS = FS.getConversionSpecifier();
1230
Ted Kremenekefaff192010-02-27 01:41:03 +00001231 if (atFirstArg) {
1232 atFirstArg = false;
1233 usesPositionalArgs = FS.usesPositionalArg();
1234 }
1235 else if (usesPositionalArgs != FS.usesPositionalArg()) {
1236 // Cannot mix-and-match positional and non-positional arguments.
1237 S.Diag(getLocationOfByte(CS.getStart()),
1238 diag::warn_printf_mix_positional_nonpositional_args)
1239 << getFormatSpecifierRange(startSpecifier, specifierLen);
Ted Kremenek0d277352010-01-29 01:06:55 +00001240 return false;
1241 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001242
Ted Kremenekefaff192010-02-27 01:41:03 +00001243 // First check if the field width, precision, and conversion specifier
1244 // have matching data arguments.
1245 if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0,
1246 startSpecifier, specifierLen)) {
1247 return false;
1248 }
1249
1250 if (!HandleAmount(FS.getPrecision(), /* precision */ 1,
1251 startSpecifier, specifierLen)) {
Ted Kremenek0d277352010-01-29 01:06:55 +00001252 return false;
1253 }
1254
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001255 if (!CS.consumesDataArgument()) {
1256 // FIXME: Technically specifying a precision or field width here
1257 // makes no sense. Worth issuing a warning at some point.
Ted Kremenek0e5675d2010-02-10 02:16:30 +00001258 return true;
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001259 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001260
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001261 // Consume the argument.
1262 unsigned argIndex = FS.getArgIndex();
Ted Kremeneke3fc5472010-02-27 08:34:51 +00001263 if (argIndex < NumDataArgs) {
1264 // The check to see if the argIndex is valid will come later.
1265 // We set the bit here because we may exit early from this
1266 // function if we encounter some other error.
1267 CoveredArgs.set(argIndex);
1268 }
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001269
1270 // Check for using an Objective-C specific conversion specifier
1271 // in a non-ObjC literal.
1272 if (!IsObjCLiteral && CS.isObjCArg()) {
1273 return HandleInvalidConversionSpecifier(FS, startSpecifier, specifierLen);
1274 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001275
Ted Kremeneke82d8042010-01-29 01:35:25 +00001276 // Are we using '%n'? Issue a warning about this being
1277 // a possible security issue.
1278 if (CS.getKind() == ConversionSpecifier::OutIntPtrArg) {
1279 S.Diag(getLocationOfByte(CS.getStart()), diag::warn_printf_write_back)
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001280 << getFormatSpecifierRange(startSpecifier, specifierLen);
Ted Kremeneke82d8042010-01-29 01:35:25 +00001281 // Continue checking the other format specifiers.
1282 return true;
1283 }
Ted Kremenek5c41ee82010-02-11 09:27:41 +00001284
1285 if (CS.getKind() == ConversionSpecifier::VoidPtrArg) {
1286 if (FS.getPrecision().getHowSpecified() != OptionalAmount::NotSpecified)
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001287 S.Diag(getLocationOfByte(CS.getStart()),
Ted Kremenek5c41ee82010-02-11 09:27:41 +00001288 diag::warn_printf_nonsensical_precision)
1289 << CS.getCharacters()
1290 << getFormatSpecifierRange(startSpecifier, specifierLen);
1291 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001292 if (CS.getKind() == ConversionSpecifier::VoidPtrArg ||
1293 CS.getKind() == ConversionSpecifier::CStrArg) {
Ted Kremenek5c41ee82010-02-11 09:27:41 +00001294 // FIXME: Instead of using "0", "+", etc., eventually get them from
1295 // the FormatSpecifier.
1296 if (FS.hasLeadingZeros())
1297 HandleFlags(FS, "0", CS.getCharacters(), startSpecifier, specifierLen);
1298 if (FS.hasPlusPrefix())
1299 HandleFlags(FS, "+", CS.getCharacters(), startSpecifier, specifierLen);
1300 if (FS.hasSpacePrefix())
1301 HandleFlags(FS, " ", CS.getCharacters(), startSpecifier, specifierLen);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001302 }
1303
Ted Kremenekda51f0d2010-01-29 01:43:31 +00001304 // The remaining checks depend on the data arguments.
1305 if (HasVAListArg)
1306 return true;
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001307
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001308 if (argIndex >= NumDataArgs) {
Ted Kremenek6ee76532010-03-25 03:59:12 +00001309 if (FS.usesPositionalArg()) {
1310 S.Diag(getLocationOfByte(CS.getStart()),
1311 diag::warn_printf_positional_arg_exceeds_data_args)
1312 << (argIndex+1) << NumDataArgs
1313 << getFormatSpecifierRange(startSpecifier, specifierLen);
1314 }
1315 else {
1316 S.Diag(getLocationOfByte(CS.getStart()),
1317 diag::warn_printf_insufficient_data_args)
1318 << getFormatSpecifierRange(startSpecifier, specifierLen);
1319 }
1320
Ted Kremenekda51f0d2010-01-29 01:43:31 +00001321 // Don't do any more checking.
1322 return false;
1323 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001324
Ted Kremenekd635c5f2010-01-30 00:49:51 +00001325 // Now type check the data expression that matches the
1326 // format specifier.
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001327 const Expr *Ex = getDataArg(argIndex);
Ted Kremenekd635c5f2010-01-30 00:49:51 +00001328 const analyze_printf::ArgTypeResult &ATR = FS.getArgType(S.Context);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001329 if (ATR.isValid() && !ATR.matchesType(S.Context, Ex->getType())) {
1330 // Check if we didn't match because of an implicit cast from a 'char'
1331 // or 'short' to an 'int'. This is done because printf is a varargs
1332 // function.
1333 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Ex))
1334 if (ICE->getType() == S.Context.IntTy)
1335 if (ATR.matchesType(S.Context, ICE->getSubExpr()->getType()))
1336 return true;
Ted Kremenek105d41c2010-02-01 19:38:10 +00001337
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001338 S.Diag(getLocationOfByte(CS.getStart()),
1339 diag::warn_printf_conversion_argument_type_mismatch)
1340 << ATR.getRepresentativeType(S.Context) << Ex->getType()
Ted Kremenek1497bff2010-02-11 19:37:25 +00001341 << getFormatSpecifierRange(startSpecifier, specifierLen)
1342 << Ex->getSourceRange();
Ted Kremenekd635c5f2010-01-30 00:49:51 +00001343 }
Ted Kremeneke0e53132010-01-28 23:39:18 +00001344
1345 return true;
1346}
1347
Ted Kremenek07d161f2010-01-29 01:50:07 +00001348void CheckPrintfHandler::DoneProcessing() {
1349 // Does the number of data arguments exceed the number of
1350 // format conversions in the format string?
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001351 if (!HasVAListArg) {
1352 // Find any arguments that weren't covered.
1353 CoveredArgs.flip();
1354 signed notCoveredArg = CoveredArgs.find_first();
1355 if (notCoveredArg >= 0) {
1356 assert((unsigned)notCoveredArg < NumDataArgs);
1357 S.Diag(getDataArg((unsigned) notCoveredArg)->getLocStart(),
1358 diag::warn_printf_data_arg_not_used)
1359 << getFormatStringRange();
1360 }
1361 }
Ted Kremenek07d161f2010-01-29 01:50:07 +00001362}
Ted Kremeneke0e53132010-01-28 23:39:18 +00001363
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001364void Sema::CheckPrintfString(const StringLiteral *FExpr,
Ted Kremenek0e5675d2010-02-10 02:16:30 +00001365 const Expr *OrigFormatExpr,
1366 const CallExpr *TheCall, bool HasVAListArg,
1367 unsigned format_idx, unsigned firstDataArg) {
1368
Ted Kremeneke0e53132010-01-28 23:39:18 +00001369 // CHECK: is the format string a wide literal?
1370 if (FExpr->isWide()) {
1371 Diag(FExpr->getLocStart(),
1372 diag::warn_printf_format_string_is_wide_literal)
1373 << OrigFormatExpr->getSourceRange();
1374 return;
1375 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001376
Ted Kremeneke0e53132010-01-28 23:39:18 +00001377 // Str - The format string. NOTE: this is NOT null-terminated!
1378 const char *Str = FExpr->getStrData();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001379
Ted Kremeneke0e53132010-01-28 23:39:18 +00001380 // CHECK: empty format string?
1381 unsigned StrLen = FExpr->getByteLength();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001382
Ted Kremeneke0e53132010-01-28 23:39:18 +00001383 if (StrLen == 0) {
1384 Diag(FExpr->getLocStart(), diag::warn_printf_empty_format_string)
1385 << OrigFormatExpr->getSourceRange();
1386 return;
1387 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001388
Ted Kremenek6ee76532010-03-25 03:59:12 +00001389 CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
Ted Kremeneke0e53132010-01-28 23:39:18 +00001390 TheCall->getNumArgs() - firstDataArg,
Ted Kremenek0d277352010-01-29 01:06:55 +00001391 isa<ObjCStringLiteral>(OrigFormatExpr), Str,
1392 HasVAListArg, TheCall, format_idx);
Ted Kremeneke0e53132010-01-28 23:39:18 +00001393
Ted Kremenek74d56a12010-02-04 20:46:58 +00001394 if (!analyze_printf::ParseFormatString(H, Str, Str + StrLen))
Ted Kremenek808015a2010-01-29 03:16:21 +00001395 H.DoneProcessing();
Ted Kremenekce7024e2010-01-28 01:18:22 +00001396}
1397
Ted Kremenek06de2762007-08-17 16:46:58 +00001398//===--- CHECK: Return Address of Stack Variable --------------------------===//
1399
1400static DeclRefExpr* EvalVal(Expr *E);
1401static DeclRefExpr* EvalAddr(Expr* E);
1402
1403/// CheckReturnStackAddr - Check if a return statement returns the address
1404/// of a stack variable.
1405void
1406Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType,
1407 SourceLocation ReturnLoc) {
Mike Stump1eb44332009-09-09 15:08:12 +00001408
Ted Kremenek06de2762007-08-17 16:46:58 +00001409 // Perform checking for returned stack addresses.
Steve Naroffdd972f22008-09-05 22:11:13 +00001410 if (lhsType->isPointerType() || lhsType->isBlockPointerType()) {
Ted Kremenek06de2762007-08-17 16:46:58 +00001411 if (DeclRefExpr *DR = EvalAddr(RetValExp))
Chris Lattner3c73c412008-11-19 08:23:25 +00001412 Diag(DR->getLocStart(), diag::warn_ret_stack_addr)
Chris Lattner08631c52008-11-23 21:45:46 +00001413 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange();
Mike Stump1eb44332009-09-09 15:08:12 +00001414
Steve Naroffc50a4a52008-09-16 22:25:10 +00001415 // Skip over implicit cast expressions when checking for block expressions.
Chris Lattner4ca606e2009-09-08 00:36:37 +00001416 RetValExp = RetValExp->IgnoreParenCasts();
Steve Naroffc50a4a52008-09-16 22:25:10 +00001417
Chris Lattner9e6b37a2009-10-30 04:01:58 +00001418 if (BlockExpr *C = dyn_cast<BlockExpr>(RetValExp))
Mike Stump397195b2009-04-17 00:09:41 +00001419 if (C->hasBlockDeclRefExprs())
1420 Diag(C->getLocStart(), diag::err_ret_local_block)
1421 << C->getSourceRange();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001422
Chris Lattner9e6b37a2009-10-30 04:01:58 +00001423 if (AddrLabelExpr *ALE = dyn_cast<AddrLabelExpr>(RetValExp))
1424 Diag(ALE->getLocStart(), diag::warn_ret_addr_label)
1425 << ALE->getSourceRange();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001426
Mike Stumpac5fc7c2009-08-04 21:02:39 +00001427 } else if (lhsType->isReferenceType()) {
1428 // Perform checking for stack values returned by reference.
Douglas Gregor49badde2008-10-27 19:41:14 +00001429 // Check for a reference to the stack
1430 if (DeclRefExpr *DR = EvalVal(RetValExp))
Chris Lattnerdcd5ef12008-11-19 05:27:50 +00001431 Diag(DR->getLocStart(), diag::warn_ret_stack_ref)
Chris Lattner08631c52008-11-23 21:45:46 +00001432 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange();
Ted Kremenek06de2762007-08-17 16:46:58 +00001433 }
1434}
1435
1436/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that
1437/// check if the expression in a return statement evaluates to an address
1438/// to a location on the stack. The recursion is used to traverse the
1439/// AST of the return expression, with recursion backtracking when we
1440/// encounter a subexpression that (1) clearly does not lead to the address
1441/// of a stack variable or (2) is something we cannot determine leads to
1442/// the address of a stack variable based on such local checking.
1443///
Ted Kremeneke8c600f2007-08-28 17:02:55 +00001444/// EvalAddr processes expressions that are pointers that are used as
1445/// references (and not L-values). EvalVal handles all other values.
Mike Stump1eb44332009-09-09 15:08:12 +00001446/// At the base case of the recursion is a check for a DeclRefExpr* in
Ted Kremenek06de2762007-08-17 16:46:58 +00001447/// the refers to a stack variable.
1448///
1449/// This implementation handles:
1450///
1451/// * pointer-to-pointer casts
1452/// * implicit conversions from array references to pointers
1453/// * taking the address of fields
1454/// * arbitrary interplay between "&" and "*" operators
1455/// * pointer arithmetic from an address of a stack variable
1456/// * taking the address of an array element where the array is on the stack
1457static DeclRefExpr* EvalAddr(Expr *E) {
Ted Kremenek06de2762007-08-17 16:46:58 +00001458 // We should only be called for evaluating pointer expressions.
David Chisnall0f436562009-08-17 16:35:33 +00001459 assert((E->getType()->isAnyPointerType() ||
Steve Naroffdd972f22008-09-05 22:11:13 +00001460 E->getType()->isBlockPointerType() ||
Ted Kremeneka526c5c2008-01-07 19:49:32 +00001461 E->getType()->isObjCQualifiedIdType()) &&
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001462 "EvalAddr only works on pointers");
Mike Stump1eb44332009-09-09 15:08:12 +00001463
Ted Kremenek06de2762007-08-17 16:46:58 +00001464 // Our "symbolic interpreter" is just a dispatch off the currently
1465 // viewed AST node. We then recursively traverse the AST by calling
1466 // EvalAddr and EvalVal appropriately.
1467 switch (E->getStmtClass()) {
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001468 case Stmt::ParenExprClass:
1469 // Ignore parentheses.
1470 return EvalAddr(cast<ParenExpr>(E)->getSubExpr());
Ted Kremenek06de2762007-08-17 16:46:58 +00001471
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001472 case Stmt::UnaryOperatorClass: {
1473 // The only unary operator that make sense to handle here
1474 // is AddrOf. All others don't make sense as pointers.
1475 UnaryOperator *U = cast<UnaryOperator>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00001476
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001477 if (U->getOpcode() == UnaryOperator::AddrOf)
1478 return EvalVal(U->getSubExpr());
1479 else
Ted Kremenek06de2762007-08-17 16:46:58 +00001480 return NULL;
1481 }
Mike Stump1eb44332009-09-09 15:08:12 +00001482
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001483 case Stmt::BinaryOperatorClass: {
1484 // Handle pointer arithmetic. All other binary operators are not valid
1485 // in this context.
1486 BinaryOperator *B = cast<BinaryOperator>(E);
1487 BinaryOperator::Opcode op = B->getOpcode();
Mike Stump1eb44332009-09-09 15:08:12 +00001488
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001489 if (op != BinaryOperator::Add && op != BinaryOperator::Sub)
1490 return NULL;
Mike Stump1eb44332009-09-09 15:08:12 +00001491
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001492 Expr *Base = B->getLHS();
1493
1494 // Determine which argument is the real pointer base. It could be
1495 // the RHS argument instead of the LHS.
1496 if (!Base->getType()->isPointerType()) Base = B->getRHS();
Mike Stump1eb44332009-09-09 15:08:12 +00001497
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001498 assert (Base->getType()->isPointerType());
1499 return EvalAddr(Base);
1500 }
Steve Naroff61f40a22008-09-10 19:17:48 +00001501
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001502 // For conditional operators we need to see if either the LHS or RHS are
1503 // valid DeclRefExpr*s. If one of them is valid, we return it.
1504 case Stmt::ConditionalOperatorClass: {
1505 ConditionalOperator *C = cast<ConditionalOperator>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00001506
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001507 // Handle the GNU extension for missing LHS.
1508 if (Expr *lhsExpr = C->getLHS())
1509 if (DeclRefExpr* LHS = EvalAddr(lhsExpr))
1510 return LHS;
1511
1512 return EvalAddr(C->getRHS());
1513 }
Mike Stump1eb44332009-09-09 15:08:12 +00001514
Ted Kremenek54b52742008-08-07 00:49:01 +00001515 // For casts, we need to handle conversions from arrays to
1516 // pointer values, and pointer-to-pointer conversions.
Douglas Gregor49badde2008-10-27 19:41:14 +00001517 case Stmt::ImplicitCastExprClass:
Douglas Gregor6eec8e82008-10-28 15:36:24 +00001518 case Stmt::CStyleCastExprClass:
Douglas Gregor49badde2008-10-27 19:41:14 +00001519 case Stmt::CXXFunctionalCastExprClass: {
Argyrios Kyrtzidis0835a3c2008-08-18 23:01:59 +00001520 Expr* SubExpr = cast<CastExpr>(E)->getSubExpr();
Ted Kremenek54b52742008-08-07 00:49:01 +00001521 QualType T = SubExpr->getType();
Mike Stump1eb44332009-09-09 15:08:12 +00001522
Steve Naroffdd972f22008-09-05 22:11:13 +00001523 if (SubExpr->getType()->isPointerType() ||
1524 SubExpr->getType()->isBlockPointerType() ||
1525 SubExpr->getType()->isObjCQualifiedIdType())
Ted Kremenek54b52742008-08-07 00:49:01 +00001526 return EvalAddr(SubExpr);
1527 else if (T->isArrayType())
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001528 return EvalVal(SubExpr);
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001529 else
Ted Kremenek54b52742008-08-07 00:49:01 +00001530 return 0;
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001531 }
Mike Stump1eb44332009-09-09 15:08:12 +00001532
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001533 // C++ casts. For dynamic casts, static casts, and const casts, we
1534 // are always converting from a pointer-to-pointer, so we just blow
Douglas Gregor49badde2008-10-27 19:41:14 +00001535 // through the cast. In the case the dynamic cast doesn't fail (and
1536 // return NULL), we take the conservative route and report cases
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001537 // where we return the address of a stack variable. For Reinterpre
Douglas Gregor49badde2008-10-27 19:41:14 +00001538 // FIXME: The comment about is wrong; we're not always converting
1539 // from pointer to pointer. I'm guessing that this code should also
Mike Stump1eb44332009-09-09 15:08:12 +00001540 // handle references to objects.
1541 case Stmt::CXXStaticCastExprClass:
1542 case Stmt::CXXDynamicCastExprClass:
Douglas Gregor49badde2008-10-27 19:41:14 +00001543 case Stmt::CXXConstCastExprClass:
1544 case Stmt::CXXReinterpretCastExprClass: {
1545 Expr *S = cast<CXXNamedCastExpr>(E)->getSubExpr();
Steve Naroffdd972f22008-09-05 22:11:13 +00001546 if (S->getType()->isPointerType() || S->getType()->isBlockPointerType())
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001547 return EvalAddr(S);
1548 else
1549 return NULL;
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001550 }
Mike Stump1eb44332009-09-09 15:08:12 +00001551
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001552 // Everything else: we simply don't reason about them.
1553 default:
1554 return NULL;
1555 }
Ted Kremenek06de2762007-08-17 16:46:58 +00001556}
Mike Stump1eb44332009-09-09 15:08:12 +00001557
Ted Kremenek06de2762007-08-17 16:46:58 +00001558
1559/// EvalVal - This function is complements EvalAddr in the mutual recursion.
1560/// See the comments for EvalAddr for more details.
1561static DeclRefExpr* EvalVal(Expr *E) {
Mike Stump1eb44332009-09-09 15:08:12 +00001562
Ted Kremeneke8c600f2007-08-28 17:02:55 +00001563 // We should only be called for evaluating non-pointer expressions, or
1564 // expressions with a pointer type that are not used as references but instead
1565 // are l-values (e.g., DeclRefExpr with a pointer type).
Mike Stump1eb44332009-09-09 15:08:12 +00001566
Ted Kremenek06de2762007-08-17 16:46:58 +00001567 // Our "symbolic interpreter" is just a dispatch off the currently
1568 // viewed AST node. We then recursively traverse the AST by calling
1569 // EvalAddr and EvalVal appropriately.
1570 switch (E->getStmtClass()) {
Douglas Gregora2813ce2009-10-23 18:54:35 +00001571 case Stmt::DeclRefExprClass: {
Ted Kremenek06de2762007-08-17 16:46:58 +00001572 // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking
1573 // at code that refers to a variable's name. We check if it has local
1574 // storage within the function, and if so, return the expression.
1575 DeclRefExpr *DR = cast<DeclRefExpr>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00001576
Ted Kremenek06de2762007-08-17 16:46:58 +00001577 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl()))
Mike Stump1eb44332009-09-09 15:08:12 +00001578 if (V->hasLocalStorage() && !V->getType()->isReferenceType()) return DR;
1579
Ted Kremenek06de2762007-08-17 16:46:58 +00001580 return NULL;
1581 }
Mike Stump1eb44332009-09-09 15:08:12 +00001582
Ted Kremenek06de2762007-08-17 16:46:58 +00001583 case Stmt::ParenExprClass:
1584 // Ignore parentheses.
1585 return EvalVal(cast<ParenExpr>(E)->getSubExpr());
Mike Stump1eb44332009-09-09 15:08:12 +00001586
Ted Kremenek06de2762007-08-17 16:46:58 +00001587 case Stmt::UnaryOperatorClass: {
1588 // The only unary operator that make sense to handle here
1589 // is Deref. All others don't resolve to a "name." This includes
1590 // handling all sorts of rvalues passed to a unary operator.
1591 UnaryOperator *U = cast<UnaryOperator>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00001592
Ted Kremenek06de2762007-08-17 16:46:58 +00001593 if (U->getOpcode() == UnaryOperator::Deref)
1594 return EvalAddr(U->getSubExpr());
1595
1596 return NULL;
1597 }
Mike Stump1eb44332009-09-09 15:08:12 +00001598
Ted Kremenek06de2762007-08-17 16:46:58 +00001599 case Stmt::ArraySubscriptExprClass: {
1600 // Array subscripts are potential references to data on the stack. We
1601 // retrieve the DeclRefExpr* for the array variable if it indeed
1602 // has local storage.
Ted Kremenek23245122007-08-20 16:18:38 +00001603 return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase());
Ted Kremenek06de2762007-08-17 16:46:58 +00001604 }
Mike Stump1eb44332009-09-09 15:08:12 +00001605
Ted Kremenek06de2762007-08-17 16:46:58 +00001606 case Stmt::ConditionalOperatorClass: {
1607 // For conditional operators we need to see if either the LHS or RHS are
1608 // non-NULL DeclRefExpr's. If one is non-NULL, we return it.
1609 ConditionalOperator *C = cast<ConditionalOperator>(E);
1610
Anders Carlsson39073232007-11-30 19:04:31 +00001611 // Handle the GNU extension for missing LHS.
1612 if (Expr *lhsExpr = C->getLHS())
1613 if (DeclRefExpr *LHS = EvalVal(lhsExpr))
1614 return LHS;
1615
1616 return EvalVal(C->getRHS());
Ted Kremenek06de2762007-08-17 16:46:58 +00001617 }
Mike Stump1eb44332009-09-09 15:08:12 +00001618
Ted Kremenek06de2762007-08-17 16:46:58 +00001619 // Accesses to members are potential references to data on the stack.
Douglas Gregor83f6faf2009-08-31 23:41:50 +00001620 case Stmt::MemberExprClass: {
Ted Kremenek06de2762007-08-17 16:46:58 +00001621 MemberExpr *M = cast<MemberExpr>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00001622
Ted Kremenek06de2762007-08-17 16:46:58 +00001623 // Check for indirect access. We only want direct field accesses.
1624 if (!M->isArrow())
1625 return EvalVal(M->getBase());
1626 else
1627 return NULL;
1628 }
Mike Stump1eb44332009-09-09 15:08:12 +00001629
Ted Kremenek06de2762007-08-17 16:46:58 +00001630 // Everything else: we simply don't reason about them.
1631 default:
1632 return NULL;
1633 }
1634}
Ted Kremenek588e5eb2007-11-25 00:58:00 +00001635
1636//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===//
1637
1638/// Check for comparisons of floating point operands using != and ==.
1639/// Issue a warning if these are no self-comparisons, as they are not likely
1640/// to do what the programmer intended.
1641void Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) {
1642 bool EmitWarning = true;
Mike Stump1eb44332009-09-09 15:08:12 +00001643
Ted Kremenek4e99a5f2008-01-17 16:57:34 +00001644 Expr* LeftExprSansParen = lex->IgnoreParens();
Ted Kremenek32e97b62008-01-17 17:55:13 +00001645 Expr* RightExprSansParen = rex->IgnoreParens();
Ted Kremenek588e5eb2007-11-25 00:58:00 +00001646
1647 // Special case: check for x == x (which is OK).
1648 // Do not emit warnings for such cases.
1649 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen))
1650 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen))
1651 if (DRL->getDecl() == DRR->getDecl())
1652 EmitWarning = false;
Mike Stump1eb44332009-09-09 15:08:12 +00001653
1654
Ted Kremenek1b500bb2007-11-29 00:59:04 +00001655 // Special case: check for comparisons against literals that can be exactly
1656 // represented by APFloat. In such cases, do not emit a warning. This
1657 // is a heuristic: often comparison against such literals are used to
1658 // detect if a value in a variable has not changed. This clearly can
1659 // lead to false negatives.
1660 if (EmitWarning) {
1661 if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) {
1662 if (FLL->isExact())
1663 EmitWarning = false;
Mike Stumpac5fc7c2009-08-04 21:02:39 +00001664 } else
Ted Kremenek1b500bb2007-11-29 00:59:04 +00001665 if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){
1666 if (FLR->isExact())
1667 EmitWarning = false;
1668 }
1669 }
Mike Stump1eb44332009-09-09 15:08:12 +00001670
Ted Kremenek588e5eb2007-11-25 00:58:00 +00001671 // Check for comparisons with builtin types.
Sebastian Redl0eb23302009-01-19 00:08:26 +00001672 if (EmitWarning)
Ted Kremenek588e5eb2007-11-25 00:58:00 +00001673 if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen))
Douglas Gregor3c385e52009-02-14 18:57:46 +00001674 if (CL->isBuiltinCall(Context))
Ted Kremenek588e5eb2007-11-25 00:58:00 +00001675 EmitWarning = false;
Mike Stump1eb44332009-09-09 15:08:12 +00001676
Sebastian Redl0eb23302009-01-19 00:08:26 +00001677 if (EmitWarning)
Ted Kremenek588e5eb2007-11-25 00:58:00 +00001678 if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen))
Douglas Gregor3c385e52009-02-14 18:57:46 +00001679 if (CR->isBuiltinCall(Context))
Ted Kremenek588e5eb2007-11-25 00:58:00 +00001680 EmitWarning = false;
Mike Stump1eb44332009-09-09 15:08:12 +00001681
Ted Kremenek588e5eb2007-11-25 00:58:00 +00001682 // Emit the diagnostic.
1683 if (EmitWarning)
Chris Lattnerfa25bbb2008-11-19 05:08:23 +00001684 Diag(loc, diag::warn_floatingpoint_eq)
1685 << lex->getSourceRange() << rex->getSourceRange();
Ted Kremenek588e5eb2007-11-25 00:58:00 +00001686}
John McCallba26e582010-01-04 23:21:16 +00001687
John McCallf2370c92010-01-06 05:24:50 +00001688//===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===//
1689//===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===//
John McCallba26e582010-01-04 23:21:16 +00001690
John McCallf2370c92010-01-06 05:24:50 +00001691namespace {
John McCallba26e582010-01-04 23:21:16 +00001692
John McCallf2370c92010-01-06 05:24:50 +00001693/// Structure recording the 'active' range of an integer-valued
1694/// expression.
1695struct IntRange {
1696 /// The number of bits active in the int.
1697 unsigned Width;
John McCallba26e582010-01-04 23:21:16 +00001698
John McCallf2370c92010-01-06 05:24:50 +00001699 /// True if the int is known not to have negative values.
1700 bool NonNegative;
John McCallba26e582010-01-04 23:21:16 +00001701
John McCallf2370c92010-01-06 05:24:50 +00001702 IntRange() {}
1703 IntRange(unsigned Width, bool NonNegative)
1704 : Width(Width), NonNegative(NonNegative)
1705 {}
John McCallba26e582010-01-04 23:21:16 +00001706
John McCallf2370c92010-01-06 05:24:50 +00001707 // Returns the range of the bool type.
1708 static IntRange forBoolType() {
1709 return IntRange(1, true);
John McCall51313c32010-01-04 23:31:57 +00001710 }
1711
John McCallf2370c92010-01-06 05:24:50 +00001712 // Returns the range of an integral type.
1713 static IntRange forType(ASTContext &C, QualType T) {
1714 return forCanonicalType(C, T->getCanonicalTypeInternal().getTypePtr());
John McCall51313c32010-01-04 23:31:57 +00001715 }
1716
John McCallf2370c92010-01-06 05:24:50 +00001717 // Returns the range of an integeral type based on its canonical
1718 // representation.
1719 static IntRange forCanonicalType(ASTContext &C, const Type *T) {
1720 assert(T->isCanonicalUnqualified());
1721
1722 if (const VectorType *VT = dyn_cast<VectorType>(T))
1723 T = VT->getElementType().getTypePtr();
1724 if (const ComplexType *CT = dyn_cast<ComplexType>(T))
1725 T = CT->getElementType().getTypePtr();
1726 if (const EnumType *ET = dyn_cast<EnumType>(T))
1727 T = ET->getDecl()->getIntegerType().getTypePtr();
1728
1729 const BuiltinType *BT = cast<BuiltinType>(T);
1730 assert(BT->isInteger());
1731
1732 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
1733 }
1734
1735 // Returns the supremum of two ranges: i.e. their conservative merge.
John McCallc0cd21d2010-02-23 19:22:29 +00001736 static IntRange join(IntRange L, IntRange R) {
John McCallf2370c92010-01-06 05:24:50 +00001737 return IntRange(std::max(L.Width, R.Width),
John McCall60fad452010-01-06 22:07:33 +00001738 L.NonNegative && R.NonNegative);
1739 }
1740
1741 // Returns the infinum of two ranges: i.e. their aggressive merge.
John McCallc0cd21d2010-02-23 19:22:29 +00001742 static IntRange meet(IntRange L, IntRange R) {
John McCall60fad452010-01-06 22:07:33 +00001743 return IntRange(std::min(L.Width, R.Width),
1744 L.NonNegative || R.NonNegative);
John McCallf2370c92010-01-06 05:24:50 +00001745 }
1746};
1747
1748IntRange GetValueRange(ASTContext &C, llvm::APSInt &value, unsigned MaxWidth) {
1749 if (value.isSigned() && value.isNegative())
1750 return IntRange(value.getMinSignedBits(), false);
1751
1752 if (value.getBitWidth() > MaxWidth)
1753 value.trunc(MaxWidth);
1754
1755 // isNonNegative() just checks the sign bit without considering
1756 // signedness.
1757 return IntRange(value.getActiveBits(), true);
1758}
1759
John McCall0acc3112010-01-06 22:57:21 +00001760IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty,
John McCallf2370c92010-01-06 05:24:50 +00001761 unsigned MaxWidth) {
1762 if (result.isInt())
1763 return GetValueRange(C, result.getInt(), MaxWidth);
1764
1765 if (result.isVector()) {
John McCall0acc3112010-01-06 22:57:21 +00001766 IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth);
1767 for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) {
1768 IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth);
1769 R = IntRange::join(R, El);
1770 }
John McCallf2370c92010-01-06 05:24:50 +00001771 return R;
1772 }
1773
1774 if (result.isComplexInt()) {
1775 IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth);
1776 IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth);
1777 return IntRange::join(R, I);
John McCall51313c32010-01-04 23:31:57 +00001778 }
1779
1780 // This can happen with lossless casts to intptr_t of "based" lvalues.
1781 // Assume it might use arbitrary bits.
John McCall0acc3112010-01-06 22:57:21 +00001782 // FIXME: The only reason we need to pass the type in here is to get
1783 // the sign right on this one case. It would be nice if APValue
1784 // preserved this.
John McCallf2370c92010-01-06 05:24:50 +00001785 assert(result.isLValue());
John McCall0acc3112010-01-06 22:57:21 +00001786 return IntRange(MaxWidth, Ty->isUnsignedIntegerType());
John McCall51313c32010-01-04 23:31:57 +00001787}
John McCallf2370c92010-01-06 05:24:50 +00001788
1789/// Pseudo-evaluate the given integer expression, estimating the
1790/// range of values it might take.
1791///
1792/// \param MaxWidth - the width to which the value will be truncated
1793IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) {
1794 E = E->IgnoreParens();
1795
1796 // Try a full evaluation first.
1797 Expr::EvalResult result;
1798 if (E->Evaluate(result, C))
John McCall0acc3112010-01-06 22:57:21 +00001799 return GetValueRange(C, result.Val, E->getType(), MaxWidth);
John McCallf2370c92010-01-06 05:24:50 +00001800
1801 // I think we only want to look through implicit casts here; if the
1802 // user has an explicit widening cast, we should treat the value as
1803 // being of the new, wider type.
1804 if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) {
1805 if (CE->getCastKind() == CastExpr::CK_NoOp)
1806 return GetExprRange(C, CE->getSubExpr(), MaxWidth);
1807
1808 IntRange OutputTypeRange = IntRange::forType(C, CE->getType());
1809
John McCall60fad452010-01-06 22:07:33 +00001810 bool isIntegerCast = (CE->getCastKind() == CastExpr::CK_IntegralCast);
1811 if (!isIntegerCast && CE->getCastKind() == CastExpr::CK_Unknown)
1812 isIntegerCast = CE->getSubExpr()->getType()->isIntegerType();
1813
John McCallf2370c92010-01-06 05:24:50 +00001814 // Assume that non-integer casts can span the full range of the type.
John McCall60fad452010-01-06 22:07:33 +00001815 if (!isIntegerCast)
John McCallf2370c92010-01-06 05:24:50 +00001816 return OutputTypeRange;
1817
1818 IntRange SubRange
1819 = GetExprRange(C, CE->getSubExpr(),
1820 std::min(MaxWidth, OutputTypeRange.Width));
1821
1822 // Bail out if the subexpr's range is as wide as the cast type.
1823 if (SubRange.Width >= OutputTypeRange.Width)
1824 return OutputTypeRange;
1825
1826 // Otherwise, we take the smaller width, and we're non-negative if
1827 // either the output type or the subexpr is.
1828 return IntRange(SubRange.Width,
1829 SubRange.NonNegative || OutputTypeRange.NonNegative);
1830 }
1831
1832 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
1833 // If we can fold the condition, just take that operand.
1834 bool CondResult;
1835 if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C))
1836 return GetExprRange(C, CondResult ? CO->getTrueExpr()
1837 : CO->getFalseExpr(),
1838 MaxWidth);
1839
1840 // Otherwise, conservatively merge.
1841 IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth);
1842 IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth);
1843 return IntRange::join(L, R);
1844 }
1845
1846 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
1847 switch (BO->getOpcode()) {
1848
1849 // Boolean-valued operations are single-bit and positive.
1850 case BinaryOperator::LAnd:
1851 case BinaryOperator::LOr:
1852 case BinaryOperator::LT:
1853 case BinaryOperator::GT:
1854 case BinaryOperator::LE:
1855 case BinaryOperator::GE:
1856 case BinaryOperator::EQ:
1857 case BinaryOperator::NE:
1858 return IntRange::forBoolType();
1859
John McCallc0cd21d2010-02-23 19:22:29 +00001860 // The type of these compound assignments is the type of the LHS,
1861 // so the RHS is not necessarily an integer.
1862 case BinaryOperator::MulAssign:
1863 case BinaryOperator::DivAssign:
1864 case BinaryOperator::RemAssign:
1865 case BinaryOperator::AddAssign:
1866 case BinaryOperator::SubAssign:
1867 return IntRange::forType(C, E->getType());
1868
John McCallf2370c92010-01-06 05:24:50 +00001869 // Operations with opaque sources are black-listed.
1870 case BinaryOperator::PtrMemD:
1871 case BinaryOperator::PtrMemI:
1872 return IntRange::forType(C, E->getType());
1873
John McCall60fad452010-01-06 22:07:33 +00001874 // Bitwise-and uses the *infinum* of the two source ranges.
1875 case BinaryOperator::And:
John McCallc0cd21d2010-02-23 19:22:29 +00001876 case BinaryOperator::AndAssign:
John McCall60fad452010-01-06 22:07:33 +00001877 return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth),
1878 GetExprRange(C, BO->getRHS(), MaxWidth));
1879
John McCallf2370c92010-01-06 05:24:50 +00001880 // Left shift gets black-listed based on a judgement call.
1881 case BinaryOperator::Shl:
John McCall3aae6092010-04-07 01:14:35 +00001882 // ...except that we want to treat '1 << (blah)' as logically
1883 // positive. It's an important idiom.
1884 if (IntegerLiteral *I
1885 = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) {
1886 if (I->getValue() == 1) {
1887 IntRange R = IntRange::forType(C, E->getType());
1888 return IntRange(R.Width, /*NonNegative*/ true);
1889 }
1890 }
1891 // fallthrough
1892
John McCallc0cd21d2010-02-23 19:22:29 +00001893 case BinaryOperator::ShlAssign:
John McCallf2370c92010-01-06 05:24:50 +00001894 return IntRange::forType(C, E->getType());
1895
John McCall60fad452010-01-06 22:07:33 +00001896 // Right shift by a constant can narrow its left argument.
John McCallc0cd21d2010-02-23 19:22:29 +00001897 case BinaryOperator::Shr:
1898 case BinaryOperator::ShrAssign: {
John McCall60fad452010-01-06 22:07:33 +00001899 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
1900
1901 // If the shift amount is a positive constant, drop the width by
1902 // that much.
1903 llvm::APSInt shift;
1904 if (BO->getRHS()->isIntegerConstantExpr(shift, C) &&
1905 shift.isNonNegative()) {
1906 unsigned zext = shift.getZExtValue();
1907 if (zext >= L.Width)
1908 L.Width = (L.NonNegative ? 0 : 1);
1909 else
1910 L.Width -= zext;
1911 }
1912
1913 return L;
1914 }
1915
1916 // Comma acts as its right operand.
John McCallf2370c92010-01-06 05:24:50 +00001917 case BinaryOperator::Comma:
1918 return GetExprRange(C, BO->getRHS(), MaxWidth);
1919
John McCall60fad452010-01-06 22:07:33 +00001920 // Black-list pointer subtractions.
John McCallf2370c92010-01-06 05:24:50 +00001921 case BinaryOperator::Sub:
1922 if (BO->getLHS()->getType()->isPointerType())
1923 return IntRange::forType(C, E->getType());
1924 // fallthrough
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001925
John McCallf2370c92010-01-06 05:24:50 +00001926 default:
1927 break;
1928 }
1929
1930 // Treat every other operator as if it were closed on the
1931 // narrowest type that encompasses both operands.
1932 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
1933 IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth);
1934 return IntRange::join(L, R);
1935 }
1936
1937 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1938 switch (UO->getOpcode()) {
1939 // Boolean-valued operations are white-listed.
1940 case UnaryOperator::LNot:
1941 return IntRange::forBoolType();
1942
1943 // Operations with opaque sources are black-listed.
1944 case UnaryOperator::Deref:
1945 case UnaryOperator::AddrOf: // should be impossible
1946 case UnaryOperator::OffsetOf:
1947 return IntRange::forType(C, E->getType());
1948
1949 default:
1950 return GetExprRange(C, UO->getSubExpr(), MaxWidth);
1951 }
1952 }
1953
1954 FieldDecl *BitField = E->getBitField();
1955 if (BitField) {
1956 llvm::APSInt BitWidthAP = BitField->getBitWidth()->EvaluateAsInt(C);
1957 unsigned BitWidth = BitWidthAP.getZExtValue();
1958
1959 return IntRange(BitWidth, BitField->getType()->isUnsignedIntegerType());
1960 }
1961
1962 return IntRange::forType(C, E->getType());
1963}
John McCall51313c32010-01-04 23:31:57 +00001964
1965/// Checks whether the given value, which currently has the given
1966/// source semantics, has the same value when coerced through the
1967/// target semantics.
John McCallf2370c92010-01-06 05:24:50 +00001968bool IsSameFloatAfterCast(const llvm::APFloat &value,
1969 const llvm::fltSemantics &Src,
1970 const llvm::fltSemantics &Tgt) {
John McCall51313c32010-01-04 23:31:57 +00001971 llvm::APFloat truncated = value;
1972
1973 bool ignored;
1974 truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored);
1975 truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored);
1976
1977 return truncated.bitwiseIsEqual(value);
1978}
1979
1980/// Checks whether the given value, which currently has the given
1981/// source semantics, has the same value when coerced through the
1982/// target semantics.
1983///
1984/// The value might be a vector of floats (or a complex number).
John McCallf2370c92010-01-06 05:24:50 +00001985bool IsSameFloatAfterCast(const APValue &value,
1986 const llvm::fltSemantics &Src,
1987 const llvm::fltSemantics &Tgt) {
John McCall51313c32010-01-04 23:31:57 +00001988 if (value.isFloat())
1989 return IsSameFloatAfterCast(value.getFloat(), Src, Tgt);
1990
1991 if (value.isVector()) {
1992 for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i)
1993 if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt))
1994 return false;
1995 return true;
1996 }
1997
1998 assert(value.isComplexFloat());
1999 return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) &&
2000 IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt));
2001}
2002
John McCallf2370c92010-01-06 05:24:50 +00002003} // end anonymous namespace
John McCall51313c32010-01-04 23:31:57 +00002004
John McCallba26e582010-01-04 23:21:16 +00002005/// \brief Implements -Wsign-compare.
2006///
2007/// \param lex the left-hand expression
2008/// \param rex the right-hand expression
2009/// \param OpLoc the location of the joining operator
John McCalld1b47bf2010-03-11 19:43:18 +00002010/// \param BinOpc binary opcode or 0
John McCallba26e582010-01-04 23:21:16 +00002011void Sema::CheckSignCompare(Expr *lex, Expr *rex, SourceLocation OpLoc,
John McCalld1b47bf2010-03-11 19:43:18 +00002012 const BinaryOperator::Opcode* BinOpc) {
John McCallba26e582010-01-04 23:21:16 +00002013 // Don't warn if we're in an unevaluated context.
2014 if (ExprEvalContexts.back().Context == Unevaluated)
2015 return;
2016
John McCallf2370c92010-01-06 05:24:50 +00002017 // If either expression is value-dependent, don't warn. We'll get another
2018 // chance at instantiation time.
2019 if (lex->isValueDependent() || rex->isValueDependent())
2020 return;
2021
John McCallba26e582010-01-04 23:21:16 +00002022 QualType lt = lex->getType(), rt = rex->getType();
2023
2024 // Only warn if both operands are integral.
2025 if (!lt->isIntegerType() || !rt->isIntegerType())
2026 return;
2027
John McCallf2370c92010-01-06 05:24:50 +00002028 // In C, the width of a bitfield determines its type, and the
2029 // declared type only contributes the signedness. This duplicates
2030 // the work that will later be done by UsualUnaryConversions.
2031 // Eventually, this check will be reorganized in a way that avoids
2032 // this duplication.
2033 if (!getLangOptions().CPlusPlus) {
2034 QualType tmp;
2035 tmp = Context.isPromotableBitField(lex);
2036 if (!tmp.isNull()) lt = tmp;
2037 tmp = Context.isPromotableBitField(rex);
2038 if (!tmp.isNull()) rt = tmp;
2039 }
John McCallba26e582010-01-04 23:21:16 +00002040
John McCalla2936be2010-03-19 18:53:26 +00002041 if (const EnumType *E = lt->getAs<EnumType>())
2042 lt = E->getDecl()->getPromotionType();
2043 if (const EnumType *E = rt->getAs<EnumType>())
2044 rt = E->getDecl()->getPromotionType();
2045
John McCallba26e582010-01-04 23:21:16 +00002046 // The rule is that the signed operand becomes unsigned, so isolate the
2047 // signed operand.
John McCallf2370c92010-01-06 05:24:50 +00002048 Expr *signedOperand = lex, *unsignedOperand = rex;
2049 QualType signedType = lt, unsignedType = rt;
John McCallba26e582010-01-04 23:21:16 +00002050 if (lt->isSignedIntegerType()) {
2051 if (rt->isSignedIntegerType()) return;
John McCallba26e582010-01-04 23:21:16 +00002052 } else {
2053 if (!rt->isSignedIntegerType()) return;
John McCallf2370c92010-01-06 05:24:50 +00002054 std::swap(signedOperand, unsignedOperand);
2055 std::swap(signedType, unsignedType);
John McCallba26e582010-01-04 23:21:16 +00002056 }
2057
John McCallf2370c92010-01-06 05:24:50 +00002058 unsigned unsignedWidth = Context.getIntWidth(unsignedType);
2059 unsigned signedWidth = Context.getIntWidth(signedType);
2060
John McCallba26e582010-01-04 23:21:16 +00002061 // If the unsigned type is strictly smaller than the signed type,
2062 // then (1) the result type will be signed and (2) the unsigned
2063 // value will fit fully within the signed type, and thus the result
2064 // of the comparison will be exact.
John McCallf2370c92010-01-06 05:24:50 +00002065 if (signedWidth > unsignedWidth)
John McCallba26e582010-01-04 23:21:16 +00002066 return;
2067
John McCallf2370c92010-01-06 05:24:50 +00002068 // Otherwise, calculate the effective ranges.
2069 IntRange signedRange = GetExprRange(Context, signedOperand, signedWidth);
2070 IntRange unsignedRange = GetExprRange(Context, unsignedOperand, unsignedWidth);
2071
2072 // We should never be unable to prove that the unsigned operand is
2073 // non-negative.
2074 assert(unsignedRange.NonNegative && "unsigned range includes negative?");
2075
2076 // If the signed operand is non-negative, then the signed->unsigned
2077 // conversion won't change it.
John McCalld1b47bf2010-03-11 19:43:18 +00002078 if (signedRange.NonNegative) {
2079 // Emit warnings for comparisons of unsigned to integer constant 0.
2080 // always false: x < 0 (or 0 > x)
2081 // always true: x >= 0 (or 0 <= x)
2082 llvm::APSInt X;
2083 if (BinOpc && signedOperand->isIntegerConstantExpr(X, Context) && X == 0) {
2084 if (signedOperand != lex) {
2085 if (*BinOpc == BinaryOperator::LT) {
2086 Diag(OpLoc, diag::warn_lunsigned_always_true_comparison)
2087 << "< 0" << "false"
2088 << lex->getSourceRange() << rex->getSourceRange();
2089 }
2090 else if (*BinOpc == BinaryOperator::GE) {
2091 Diag(OpLoc, diag::warn_lunsigned_always_true_comparison)
2092 << ">= 0" << "true"
2093 << lex->getSourceRange() << rex->getSourceRange();
2094 }
2095 }
2096 else {
2097 if (*BinOpc == BinaryOperator::GT) {
2098 Diag(OpLoc, diag::warn_runsigned_always_true_comparison)
2099 << "0 >" << "false"
2100 << lex->getSourceRange() << rex->getSourceRange();
2101 }
2102 else if (*BinOpc == BinaryOperator::LE) {
2103 Diag(OpLoc, diag::warn_runsigned_always_true_comparison)
2104 << "0 <=" << "true"
2105 << lex->getSourceRange() << rex->getSourceRange();
2106 }
2107 }
2108 }
John McCallba26e582010-01-04 23:21:16 +00002109 return;
John McCalld1b47bf2010-03-11 19:43:18 +00002110 }
John McCallba26e582010-01-04 23:21:16 +00002111
2112 // For (in)equality comparisons, if the unsigned operand is a
2113 // constant which cannot collide with a overflowed signed operand,
2114 // then reinterpreting the signed operand as unsigned will not
2115 // change the result of the comparison.
John McCalld1b47bf2010-03-11 19:43:18 +00002116 if (BinOpc &&
2117 (*BinOpc == BinaryOperator::EQ || *BinOpc == BinaryOperator::NE) &&
2118 unsignedRange.Width < unsignedWidth)
John McCallba26e582010-01-04 23:21:16 +00002119 return;
2120
John McCalld1b47bf2010-03-11 19:43:18 +00002121 Diag(OpLoc, BinOpc ? diag::warn_mixed_sign_comparison
2122 : diag::warn_mixed_sign_conditional)
John McCallf2370c92010-01-06 05:24:50 +00002123 << lt << rt << lex->getSourceRange() << rex->getSourceRange();
John McCallba26e582010-01-04 23:21:16 +00002124}
2125
John McCall51313c32010-01-04 23:31:57 +00002126/// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
2127static void DiagnoseImpCast(Sema &S, Expr *E, QualType T, unsigned diag) {
2128 S.Diag(E->getExprLoc(), diag) << E->getType() << T << E->getSourceRange();
2129}
2130
2131/// Implements -Wconversion.
2132void Sema::CheckImplicitConversion(Expr *E, QualType T) {
2133 // Don't diagnose in unevaluated contexts.
2134 if (ExprEvalContexts.back().Context == Sema::Unevaluated)
2135 return;
2136
2137 // Don't diagnose for value-dependent expressions.
2138 if (E->isValueDependent())
2139 return;
2140
2141 const Type *Source = Context.getCanonicalType(E->getType()).getTypePtr();
2142 const Type *Target = Context.getCanonicalType(T).getTypePtr();
2143
2144 // Never diagnose implicit casts to bool.
2145 if (Target->isSpecificBuiltinType(BuiltinType::Bool))
2146 return;
2147
2148 // Strip vector types.
2149 if (isa<VectorType>(Source)) {
2150 if (!isa<VectorType>(Target))
2151 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_vector_scalar);
2152
2153 Source = cast<VectorType>(Source)->getElementType().getTypePtr();
2154 Target = cast<VectorType>(Target)->getElementType().getTypePtr();
2155 }
2156
2157 // Strip complex types.
2158 if (isa<ComplexType>(Source)) {
2159 if (!isa<ComplexType>(Target))
2160 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_complex_scalar);
2161
2162 Source = cast<ComplexType>(Source)->getElementType().getTypePtr();
2163 Target = cast<ComplexType>(Target)->getElementType().getTypePtr();
2164 }
2165
2166 const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source);
2167 const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target);
2168
2169 // If the source is floating point...
2170 if (SourceBT && SourceBT->isFloatingPoint()) {
2171 // ...and the target is floating point...
2172 if (TargetBT && TargetBT->isFloatingPoint()) {
2173 // ...then warn if we're dropping FP rank.
2174
2175 // Builtin FP kinds are ordered by increasing FP rank.
2176 if (SourceBT->getKind() > TargetBT->getKind()) {
2177 // Don't warn about float constants that are precisely
2178 // representable in the target type.
2179 Expr::EvalResult result;
2180 if (E->Evaluate(result, Context)) {
2181 // Value might be a float, a float vector, or a float complex.
2182 if (IsSameFloatAfterCast(result.Val,
2183 Context.getFloatTypeSemantics(QualType(TargetBT, 0)),
2184 Context.getFloatTypeSemantics(QualType(SourceBT, 0))))
2185 return;
2186 }
2187
2188 DiagnoseImpCast(*this, E, T, diag::warn_impcast_float_precision);
2189 }
2190 return;
2191 }
2192
2193 // If the target is integral, always warn.
2194 if ((TargetBT && TargetBT->isInteger()))
2195 // TODO: don't warn for integer values?
2196 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_float_integer);
2197
2198 return;
2199 }
2200
John McCallf2370c92010-01-06 05:24:50 +00002201 if (!Source->isIntegerType() || !Target->isIntegerType())
John McCall51313c32010-01-04 23:31:57 +00002202 return;
2203
John McCallf2370c92010-01-06 05:24:50 +00002204 IntRange SourceRange = GetExprRange(Context, E, Context.getIntWidth(E->getType()));
2205 IntRange TargetRange = IntRange::forCanonicalType(Context, Target);
John McCall51313c32010-01-04 23:31:57 +00002206
John McCallf2370c92010-01-06 05:24:50 +00002207 // FIXME: also signed<->unsigned?
2208
2209 if (SourceRange.Width > TargetRange.Width) {
John McCall51313c32010-01-04 23:31:57 +00002210 // People want to build with -Wshorten-64-to-32 and not -Wconversion
2211 // and by god we'll let them.
John McCallf2370c92010-01-06 05:24:50 +00002212 if (SourceRange.Width == 64 && TargetRange.Width == 32)
John McCall51313c32010-01-04 23:31:57 +00002213 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_integer_64_32);
2214 return DiagnoseImpCast(*this, E, T, diag::warn_impcast_integer_precision);
2215 }
2216
2217 return;
2218}
2219
Mike Stumpf8c49212010-01-21 03:59:47 +00002220/// CheckParmsForFunctionDef - Check that the parameters of the given
2221/// function are appropriate for the definition of a function. This
2222/// takes care of any checks that cannot be performed on the
2223/// declaration itself, e.g., that the types of each of the function
2224/// parameters are complete.
2225bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) {
2226 bool HasInvalidParm = false;
2227 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
2228 ParmVarDecl *Param = FD->getParamDecl(p);
2229
2230 // C99 6.7.5.3p4: the parameters in a parameter type list in a
2231 // function declarator that is part of a function definition of
2232 // that function shall not have incomplete type.
2233 //
2234 // This is also C++ [dcl.fct]p6.
2235 if (!Param->isInvalidDecl() &&
2236 RequireCompleteType(Param->getLocation(), Param->getType(),
2237 diag::err_typecheck_decl_incomplete_type)) {
2238 Param->setInvalidDecl();
2239 HasInvalidParm = true;
2240 }
2241
2242 // C99 6.9.1p5: If the declarator includes a parameter type list, the
2243 // declaration of each parameter shall include an identifier.
2244 if (Param->getIdentifier() == 0 &&
2245 !Param->isImplicit() &&
2246 !getLangOptions().CPlusPlus)
2247 Diag(Param->getLocation(), diag::err_parameter_name_omitted);
Sam Weinigd17e3402010-02-01 05:02:49 +00002248
2249 // C99 6.7.5.3p12:
2250 // If the function declarator is not part of a definition of that
2251 // function, parameters may have incomplete type and may use the [*]
2252 // notation in their sequences of declarator specifiers to specify
2253 // variable length array types.
2254 QualType PType = Param->getOriginalType();
2255 if (const ArrayType *AT = Context.getAsArrayType(PType)) {
2256 if (AT->getSizeModifier() == ArrayType::Star) {
2257 // FIXME: This diagnosic should point the the '[*]' if source-location
2258 // information is added for it.
2259 Diag(Param->getLocation(), diag::err_array_star_in_function_definition);
2260 }
2261 }
Mike Stumpf8c49212010-01-21 03:59:47 +00002262 }
2263
2264 return HasInvalidParm;
2265}