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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
Douglas Gregore737f502010-08-12 20:07:10 +000015#include "clang/Sema/Sema.h"
John McCall2d887082010-08-25 22:03:47 +000016#include "clang/Sema/SemaInternal.h"
John McCall781472f2010-08-25 08:40:02 +000017#include "clang/Sema/ScopeInfo.h"
Ted Kremenek826a3452010-07-16 02:11:22 +000018#include "clang/Analysis/Analyses/FormatString.h"
Chris Lattner59907c42007-08-10 20:18:51 +000019#include "clang/AST/ASTContext.h"
Ken Dyck199c3d62010-01-11 17:06:35 +000020#include "clang/AST/CharUnits.h"
John McCall384aff82010-08-25 07:42:41 +000021#include "clang/AST/DeclCXX.h"
Daniel Dunbarc4a1dea2008-08-11 05:35:13 +000022#include "clang/AST/DeclObjC.h"
Ted Kremenek23245122007-08-20 16:18:38 +000023#include "clang/AST/ExprCXX.h"
Ted Kremenek7ff22b22008-06-16 18:00:42 +000024#include "clang/AST/ExprObjC.h"
Mike Stumpf8c49212010-01-21 03:59:47 +000025#include "clang/AST/DeclObjC.h"
26#include "clang/AST/StmtCXX.h"
27#include "clang/AST/StmtObjC.h"
Chris Lattner719e6152009-02-18 19:21:10 +000028#include "clang/Lex/LiteralSupport.h"
Chris Lattner59907c42007-08-10 20:18:51 +000029#include "clang/Lex/Preprocessor.h"
Mike Stumpf8c49212010-01-21 03:59:47 +000030#include "llvm/ADT/BitVector.h"
31#include "llvm/ADT/STLExtras.h"
Tom Care3bfc5f42010-06-09 04:11:11 +000032#include "llvm/Support/raw_ostream.h"
Eric Christopher691ebc32010-04-17 02:26:23 +000033#include "clang/Basic/TargetBuiltins.h"
Nate Begeman26a31422010-06-08 02:47:44 +000034#include "clang/Basic/TargetInfo.h"
Fariborz Jahanian7da71022010-09-07 19:38:13 +000035#include "clang/Basic/ConvertUTF.h"
36
Zhongxing Xua1f3dba2009-05-20 01:55:10 +000037#include <limits>
Chris Lattner59907c42007-08-10 20:18:51 +000038using namespace clang;
John McCall781472f2010-08-25 08:40:02 +000039using namespace sema;
Chris Lattner59907c42007-08-10 20:18:51 +000040
Chris Lattner60800082009-02-18 17:49:48 +000041/// getLocationOfStringLiteralByte - Return a source location that points to the
42/// specified byte of the specified string literal.
43///
44/// Strings are amazingly complex. They can be formed from multiple tokens and
45/// can have escape sequences in them in addition to the usual trigraph and
46/// escaped newline business. This routine handles this complexity.
47///
48SourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL,
49 unsigned ByteNo) const {
50 assert(!SL->isWide() && "This doesn't work for wide strings yet");
Mike Stump1eb44332009-09-09 15:08:12 +000051
Chris Lattner60800082009-02-18 17:49:48 +000052 // Loop over all of the tokens in this string until we find the one that
53 // contains the byte we're looking for.
54 unsigned TokNo = 0;
55 while (1) {
56 assert(TokNo < SL->getNumConcatenated() && "Invalid byte number!");
57 SourceLocation StrTokLoc = SL->getStrTokenLoc(TokNo);
Mike Stump1eb44332009-09-09 15:08:12 +000058
Chris Lattner60800082009-02-18 17:49:48 +000059 // Get the spelling of the string so that we can get the data that makes up
60 // the string literal, not the identifier for the macro it is potentially
61 // expanded through.
62 SourceLocation StrTokSpellingLoc = SourceMgr.getSpellingLoc(StrTokLoc);
63
64 // Re-lex the token to get its length and original spelling.
65 std::pair<FileID, unsigned> LocInfo =
66 SourceMgr.getDecomposedLoc(StrTokSpellingLoc);
Douglas Gregorf715ca12010-03-16 00:06:06 +000067 bool Invalid = false;
Benjamin Kramerf6ac97b2010-03-16 14:14:31 +000068 llvm::StringRef Buffer = SourceMgr.getBufferData(LocInfo.first, &Invalid);
Douglas Gregorf715ca12010-03-16 00:06:06 +000069 if (Invalid)
Douglas Gregoraea67db2010-03-15 22:54:52 +000070 return StrTokSpellingLoc;
71
Benjamin Kramerf6ac97b2010-03-16 14:14:31 +000072 const char *StrData = Buffer.data()+LocInfo.second;
Mike Stump1eb44332009-09-09 15:08:12 +000073
Chris Lattner60800082009-02-18 17:49:48 +000074 // Create a langops struct and enable trigraphs. This is sufficient for
75 // relexing tokens.
76 LangOptions LangOpts;
77 LangOpts.Trigraphs = true;
Mike Stump1eb44332009-09-09 15:08:12 +000078
Chris Lattner60800082009-02-18 17:49:48 +000079 // Create a lexer starting at the beginning of this token.
Benjamin Kramerf6ac97b2010-03-16 14:14:31 +000080 Lexer TheLexer(StrTokSpellingLoc, LangOpts, Buffer.begin(), StrData,
81 Buffer.end());
Chris Lattner60800082009-02-18 17:49:48 +000082 Token TheTok;
83 TheLexer.LexFromRawLexer(TheTok);
Mike Stump1eb44332009-09-09 15:08:12 +000084
Chris Lattner443e53c2009-02-18 19:26:42 +000085 // Use the StringLiteralParser to compute the length of the string in bytes.
Douglas Gregorb90f4b32010-05-26 05:35:51 +000086 StringLiteralParser SLP(&TheTok, 1, PP, /*Complain=*/false);
Chris Lattner443e53c2009-02-18 19:26:42 +000087 unsigned TokNumBytes = SLP.GetStringLength();
Mike Stump1eb44332009-09-09 15:08:12 +000088
Chris Lattner2197c962009-02-18 18:52:52 +000089 // If the byte is in this token, return the location of the byte.
Chris Lattner60800082009-02-18 17:49:48 +000090 if (ByteNo < TokNumBytes ||
91 (ByteNo == TokNumBytes && TokNo == SL->getNumConcatenated())) {
Mike Stump1eb44332009-09-09 15:08:12 +000092 unsigned Offset =
Douglas Gregorb90f4b32010-05-26 05:35:51 +000093 StringLiteralParser::getOffsetOfStringByte(TheTok, ByteNo, PP,
94 /*Complain=*/false);
Mike Stump1eb44332009-09-09 15:08:12 +000095
Chris Lattner719e6152009-02-18 19:21:10 +000096 // Now that we know the offset of the token in the spelling, use the
97 // preprocessor to get the offset in the original source.
98 return PP.AdvanceToTokenCharacter(StrTokLoc, Offset);
Chris Lattner60800082009-02-18 17:49:48 +000099 }
Mike Stump1eb44332009-09-09 15:08:12 +0000100
Chris Lattner60800082009-02-18 17:49:48 +0000101 // Move to the next string token.
102 ++TokNo;
103 ByteNo -= TokNumBytes;
104 }
105}
106
Ryan Flynn4403a5e2009-08-06 03:00:50 +0000107/// CheckablePrintfAttr - does a function call have a "printf" attribute
108/// and arguments that merit checking?
109bool Sema::CheckablePrintfAttr(const FormatAttr *Format, CallExpr *TheCall) {
110 if (Format->getType() == "printf") return true;
111 if (Format->getType() == "printf0") {
112 // printf0 allows null "format" string; if so don't check format/args
113 unsigned format_idx = Format->getFormatIdx() - 1;
Sebastian Redl4a2614e2009-11-17 18:02:24 +0000114 // Does the index refer to the implicit object argument?
115 if (isa<CXXMemberCallExpr>(TheCall)) {
116 if (format_idx == 0)
117 return false;
118 --format_idx;
119 }
Ryan Flynn4403a5e2009-08-06 03:00:50 +0000120 if (format_idx < TheCall->getNumArgs()) {
121 Expr *Format = TheCall->getArg(format_idx)->IgnoreParenCasts();
Ted Kremenekefaff192010-02-27 01:41:03 +0000122 if (!Format->isNullPointerConstant(Context,
123 Expr::NPC_ValueDependentIsNull))
Ryan Flynn4403a5e2009-08-06 03:00:50 +0000124 return true;
125 }
126 }
127 return false;
128}
Chris Lattner60800082009-02-18 17:49:48 +0000129
John McCall60d7b3a2010-08-24 06:29:42 +0000130ExprResult
Anders Carlssond406bf02009-08-16 01:56:34 +0000131Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
John McCall60d7b3a2010-08-24 06:29:42 +0000132 ExprResult TheCallResult(Owned(TheCall));
Douglas Gregor2def4832008-11-17 20:34:05 +0000133
Anders Carlssond406bf02009-08-16 01:56:34 +0000134 switch (BuiltinID) {
Chris Lattner30ce3442007-12-19 23:59:04 +0000135 case Builtin::BI__builtin___CFStringMakeConstantString:
Chris Lattner925e60d2007-12-28 05:29:59 +0000136 assert(TheCall->getNumArgs() == 1 &&
Chris Lattner1b9a0792007-12-20 00:26:33 +0000137 "Wrong # arguments to builtin CFStringMakeConstantString");
Chris Lattner69039812009-02-18 06:01:06 +0000138 if (CheckObjCString(TheCall->getArg(0)))
Sebastian Redl0eb23302009-01-19 00:08:26 +0000139 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000140 break;
Ted Kremenek49ff7a12008-07-09 17:58:53 +0000141 case Builtin::BI__builtin_stdarg_start:
Chris Lattner30ce3442007-12-19 23:59:04 +0000142 case Builtin::BI__builtin_va_start:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000143 if (SemaBuiltinVAStart(TheCall))
144 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000145 break;
Chris Lattner1b9a0792007-12-20 00:26:33 +0000146 case Builtin::BI__builtin_isgreater:
147 case Builtin::BI__builtin_isgreaterequal:
148 case Builtin::BI__builtin_isless:
149 case Builtin::BI__builtin_islessequal:
150 case Builtin::BI__builtin_islessgreater:
151 case Builtin::BI__builtin_isunordered:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000152 if (SemaBuiltinUnorderedCompare(TheCall))
153 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000154 break;
Benjamin Kramere771a7a2010-02-15 22:42:31 +0000155 case Builtin::BI__builtin_fpclassify:
156 if (SemaBuiltinFPClassification(TheCall, 6))
157 return ExprError();
158 break;
Eli Friedman9ac6f622009-08-31 20:06:00 +0000159 case Builtin::BI__builtin_isfinite:
160 case Builtin::BI__builtin_isinf:
161 case Builtin::BI__builtin_isinf_sign:
162 case Builtin::BI__builtin_isnan:
163 case Builtin::BI__builtin_isnormal:
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000164 if (SemaBuiltinFPClassification(TheCall, 1))
Eli Friedman9ac6f622009-08-31 20:06:00 +0000165 return ExprError();
166 break;
Eli Friedman6cfda232008-05-20 08:23:37 +0000167 case Builtin::BI__builtin_return_address:
Eric Christopher691ebc32010-04-17 02:26:23 +0000168 case Builtin::BI__builtin_frame_address: {
169 llvm::APSInt Result;
170 if (SemaBuiltinConstantArg(TheCall, 0, Result))
Sebastian Redl0eb23302009-01-19 00:08:26 +0000171 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000172 break;
Eric Christopher691ebc32010-04-17 02:26:23 +0000173 }
174 case Builtin::BI__builtin_eh_return_data_regno: {
175 llvm::APSInt Result;
176 if (SemaBuiltinConstantArg(TheCall, 0, Result))
Chris Lattner21fb98e2009-09-23 06:06:36 +0000177 return ExprError();
178 break;
Eric Christopher691ebc32010-04-17 02:26:23 +0000179 }
Eli Friedmand38617c2008-05-14 19:38:39 +0000180 case Builtin::BI__builtin_shufflevector:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000181 return SemaBuiltinShuffleVector(TheCall);
182 // TheCall will be freed by the smart pointer here, but that's fine, since
183 // SemaBuiltinShuffleVector guts it, but then doesn't release it.
Daniel Dunbar4493f792008-07-21 22:59:13 +0000184 case Builtin::BI__builtin_prefetch:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000185 if (SemaBuiltinPrefetch(TheCall))
186 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000187 break;
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000188 case Builtin::BI__builtin_object_size:
Sebastian Redl0eb23302009-01-19 00:08:26 +0000189 if (SemaBuiltinObjectSize(TheCall))
190 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000191 break;
Eli Friedmand875fed2009-05-03 04:46:36 +0000192 case Builtin::BI__builtin_longjmp:
193 if (SemaBuiltinLongjmp(TheCall))
194 return ExprError();
Anders Carlssond406bf02009-08-16 01:56:34 +0000195 break;
Chris Lattner5caa3702009-05-08 06:58:22 +0000196 case Builtin::BI__sync_fetch_and_add:
197 case Builtin::BI__sync_fetch_and_sub:
198 case Builtin::BI__sync_fetch_and_or:
199 case Builtin::BI__sync_fetch_and_and:
200 case Builtin::BI__sync_fetch_and_xor:
201 case Builtin::BI__sync_add_and_fetch:
202 case Builtin::BI__sync_sub_and_fetch:
203 case Builtin::BI__sync_and_and_fetch:
204 case Builtin::BI__sync_or_and_fetch:
205 case Builtin::BI__sync_xor_and_fetch:
206 case Builtin::BI__sync_val_compare_and_swap:
207 case Builtin::BI__sync_bool_compare_and_swap:
208 case Builtin::BI__sync_lock_test_and_set:
209 case Builtin::BI__sync_lock_release:
Chandler Carruthd2014572010-07-09 18:59:35 +0000210 return SemaBuiltinAtomicOverloaded(move(TheCallResult));
Nate Begeman26a31422010-06-08 02:47:44 +0000211 }
212
213 // Since the target specific builtins for each arch overlap, only check those
214 // of the arch we are compiling for.
215 if (BuiltinID >= Builtin::FirstTSBuiltin) {
216 switch (Context.Target.getTriple().getArch()) {
217 case llvm::Triple::arm:
218 case llvm::Triple::thumb:
219 if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall))
220 return ExprError();
221 break;
222 case llvm::Triple::x86:
223 case llvm::Triple::x86_64:
224 if (CheckX86BuiltinFunctionCall(BuiltinID, TheCall))
225 return ExprError();
226 break;
227 default:
228 break;
229 }
230 }
231
232 return move(TheCallResult);
233}
234
235bool Sema::CheckX86BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
236 switch (BuiltinID) {
Eric Christopher691ebc32010-04-17 02:26:23 +0000237 case X86::BI__builtin_ia32_palignr128:
238 case X86::BI__builtin_ia32_palignr: {
239 llvm::APSInt Result;
240 if (SemaBuiltinConstantArg(TheCall, 2, Result))
Nate Begeman26a31422010-06-08 02:47:44 +0000241 return true;
Eric Christopher691ebc32010-04-17 02:26:23 +0000242 break;
243 }
Anders Carlsson71993dd2007-08-17 05:31:46 +0000244 }
Nate Begeman26a31422010-06-08 02:47:44 +0000245 return false;
246}
Mike Stump1eb44332009-09-09 15:08:12 +0000247
Nate Begeman61eecf52010-06-14 05:21:25 +0000248// Get the valid immediate range for the specified NEON type code.
249static unsigned RFT(unsigned t, bool shift = false) {
250 bool quad = t & 0x10;
251
252 switch (t & 0x7) {
253 case 0: // i8
Nate Begemand69ec162010-06-17 02:26:59 +0000254 return shift ? 7 : (8 << (int)quad) - 1;
Nate Begeman61eecf52010-06-14 05:21:25 +0000255 case 1: // i16
Nate Begemand69ec162010-06-17 02:26:59 +0000256 return shift ? 15 : (4 << (int)quad) - 1;
Nate Begeman61eecf52010-06-14 05:21:25 +0000257 case 2: // i32
Nate Begemand69ec162010-06-17 02:26:59 +0000258 return shift ? 31 : (2 << (int)quad) - 1;
Nate Begeman61eecf52010-06-14 05:21:25 +0000259 case 3: // i64
Nate Begemand69ec162010-06-17 02:26:59 +0000260 return shift ? 63 : (1 << (int)quad) - 1;
Nate Begeman61eecf52010-06-14 05:21:25 +0000261 case 4: // f32
262 assert(!shift && "cannot shift float types!");
Nate Begemand69ec162010-06-17 02:26:59 +0000263 return (2 << (int)quad) - 1;
Nate Begeman61eecf52010-06-14 05:21:25 +0000264 case 5: // poly8
265 assert(!shift && "cannot shift polynomial types!");
Nate Begemand69ec162010-06-17 02:26:59 +0000266 return (8 << (int)quad) - 1;
Nate Begeman61eecf52010-06-14 05:21:25 +0000267 case 6: // poly16
268 assert(!shift && "cannot shift polynomial types!");
Nate Begemand69ec162010-06-17 02:26:59 +0000269 return (4 << (int)quad) - 1;
Nate Begeman61eecf52010-06-14 05:21:25 +0000270 case 7: // float16
271 assert(!shift && "cannot shift float types!");
Nate Begemand69ec162010-06-17 02:26:59 +0000272 return (4 << (int)quad) - 1;
Nate Begeman61eecf52010-06-14 05:21:25 +0000273 }
274 return 0;
275}
276
Nate Begeman26a31422010-06-08 02:47:44 +0000277bool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
Nate Begeman1c2a88c2010-06-09 01:10:23 +0000278 llvm::APSInt Result;
279
Nate Begeman0d15c532010-06-13 04:47:52 +0000280 unsigned mask = 0;
Nate Begeman61eecf52010-06-14 05:21:25 +0000281 unsigned TV = 0;
Nate Begeman1c2a88c2010-06-09 01:10:23 +0000282 switch (BuiltinID) {
Nate Begemana23326b2010-06-17 04:17:01 +0000283#define GET_NEON_OVERLOAD_CHECK
284#include "clang/Basic/arm_neon.inc"
285#undef GET_NEON_OVERLOAD_CHECK
Nate Begeman1c2a88c2010-06-09 01:10:23 +0000286 }
287
Nate Begeman0d15c532010-06-13 04:47:52 +0000288 // For NEON intrinsics which are overloaded on vector element type, validate
289 // the immediate which specifies which variant to emit.
290 if (mask) {
291 unsigned ArgNo = TheCall->getNumArgs()-1;
292 if (SemaBuiltinConstantArg(TheCall, ArgNo, Result))
293 return true;
294
Nate Begeman61eecf52010-06-14 05:21:25 +0000295 TV = Result.getLimitedValue(32);
296 if ((TV > 31) || (mask & (1 << TV)) == 0)
Nate Begeman0d15c532010-06-13 04:47:52 +0000297 return Diag(TheCall->getLocStart(), diag::err_invalid_neon_type_code)
298 << TheCall->getArg(ArgNo)->getSourceRange();
299 }
Nate Begeman1c2a88c2010-06-09 01:10:23 +0000300
Nate Begeman0d15c532010-06-13 04:47:52 +0000301 // For NEON intrinsics which take an immediate value as part of the
302 // instruction, range check them here.
Nate Begeman61eecf52010-06-14 05:21:25 +0000303 unsigned i = 0, l = 0, u = 0;
Nate Begeman0d15c532010-06-13 04:47:52 +0000304 switch (BuiltinID) {
305 default: return false;
Nate Begemanbb37f502010-07-29 22:48:34 +0000306 case ARM::BI__builtin_arm_ssat: i = 1; l = 1; u = 31; break;
307 case ARM::BI__builtin_arm_usat: i = 1; u = 31; break;
Nate Begeman99c40bb2010-08-03 21:32:34 +0000308 case ARM::BI__builtin_arm_vcvtr_f:
309 case ARM::BI__builtin_arm_vcvtr_d: i = 1; u = 1; break;
Nate Begemana23326b2010-06-17 04:17:01 +0000310#define GET_NEON_IMMEDIATE_CHECK
311#include "clang/Basic/arm_neon.inc"
312#undef GET_NEON_IMMEDIATE_CHECK
Nate Begeman0d15c532010-06-13 04:47:52 +0000313 };
314
Nate Begeman61eecf52010-06-14 05:21:25 +0000315 // Check that the immediate argument is actually a constant.
Nate Begeman0d15c532010-06-13 04:47:52 +0000316 if (SemaBuiltinConstantArg(TheCall, i, Result))
317 return true;
318
Nate Begeman61eecf52010-06-14 05:21:25 +0000319 // Range check against the upper/lower values for this isntruction.
Nate Begeman0d15c532010-06-13 04:47:52 +0000320 unsigned Val = Result.getZExtValue();
Nate Begeman61eecf52010-06-14 05:21:25 +0000321 if (Val < l || Val > (u + l))
Nate Begeman0d15c532010-06-13 04:47:52 +0000322 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
Benjamin Kramer476d8b82010-08-11 14:47:12 +0000323 << l << u+l << TheCall->getArg(i)->getSourceRange();
Nate Begeman0d15c532010-06-13 04:47:52 +0000324
Nate Begeman99c40bb2010-08-03 21:32:34 +0000325 // FIXME: VFP Intrinsics should error if VFP not present.
Nate Begeman26a31422010-06-08 02:47:44 +0000326 return false;
Anders Carlssond406bf02009-08-16 01:56:34 +0000327}
Daniel Dunbarde454282008-10-02 18:44:07 +0000328
Anders Carlssond406bf02009-08-16 01:56:34 +0000329/// CheckFunctionCall - Check a direct function call for various correctness
330/// and safety properties not strictly enforced by the C type system.
331bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall) {
332 // Get the IdentifierInfo* for the called function.
333 IdentifierInfo *FnInfo = FDecl->getIdentifier();
334
335 // None of the checks below are needed for functions that don't have
336 // simple names (e.g., C++ conversion functions).
337 if (!FnInfo)
338 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000339
Daniel Dunbarde454282008-10-02 18:44:07 +0000340 // FIXME: This mechanism should be abstracted to be less fragile and
341 // more efficient. For example, just map function ids to custom
342 // handlers.
343
Ted Kremenekc82faca2010-09-09 04:33:05 +0000344 // Printf and scanf checking.
345 for (specific_attr_iterator<FormatAttr>
346 i = FDecl->specific_attr_begin<FormatAttr>(),
347 e = FDecl->specific_attr_end<FormatAttr>(); i != e ; ++i) {
348
349 const FormatAttr *Format = *i;
Ted Kremenek826a3452010-07-16 02:11:22 +0000350 const bool b = Format->getType() == "scanf";
351 if (b || CheckablePrintfAttr(Format, TheCall)) {
Ted Kremenek3d692df2009-02-27 17:58:43 +0000352 bool HasVAListArg = Format->getFirstArg() == 0;
Ted Kremenek826a3452010-07-16 02:11:22 +0000353 CheckPrintfScanfArguments(TheCall, HasVAListArg,
354 Format->getFormatIdx() - 1,
355 HasVAListArg ? 0 : Format->getFirstArg() - 1,
356 !b);
Douglas Gregor3c385e52009-02-14 18:57:46 +0000357 }
Chris Lattner59907c42007-08-10 20:18:51 +0000358 }
Mike Stump1eb44332009-09-09 15:08:12 +0000359
Ted Kremenekc82faca2010-09-09 04:33:05 +0000360 for (specific_attr_iterator<NonNullAttr>
361 i = FDecl->specific_attr_begin<NonNullAttr>(),
362 e = FDecl->specific_attr_end<NonNullAttr>(); i != e; ++i) {
Sean Huntcf807c42010-08-18 23:23:40 +0000363 CheckNonNullArguments(*i, TheCall);
Ted Kremenekc82faca2010-09-09 04:33:05 +0000364 }
Sebastian Redl0eb23302009-01-19 00:08:26 +0000365
Anders Carlssond406bf02009-08-16 01:56:34 +0000366 return false;
Anders Carlsson71993dd2007-08-17 05:31:46 +0000367}
368
Anders Carlssond406bf02009-08-16 01:56:34 +0000369bool Sema::CheckBlockCall(NamedDecl *NDecl, CallExpr *TheCall) {
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000370 // Printf checking.
Argyrios Kyrtzidis40b598e2009-06-30 02:34:44 +0000371 const FormatAttr *Format = NDecl->getAttr<FormatAttr>();
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000372 if (!Format)
Anders Carlssond406bf02009-08-16 01:56:34 +0000373 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000374
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000375 const VarDecl *V = dyn_cast<VarDecl>(NDecl);
376 if (!V)
Anders Carlssond406bf02009-08-16 01:56:34 +0000377 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000378
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000379 QualType Ty = V->getType();
380 if (!Ty->isBlockPointerType())
Anders Carlssond406bf02009-08-16 01:56:34 +0000381 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000382
Ted Kremenek826a3452010-07-16 02:11:22 +0000383 const bool b = Format->getType() == "scanf";
384 if (!b && !CheckablePrintfAttr(Format, TheCall))
Anders Carlssond406bf02009-08-16 01:56:34 +0000385 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000386
Anders Carlssond406bf02009-08-16 01:56:34 +0000387 bool HasVAListArg = Format->getFirstArg() == 0;
Ted Kremenek826a3452010-07-16 02:11:22 +0000388 CheckPrintfScanfArguments(TheCall, HasVAListArg, Format->getFormatIdx() - 1,
389 HasVAListArg ? 0 : Format->getFirstArg() - 1, !b);
Anders Carlssond406bf02009-08-16 01:56:34 +0000390
391 return false;
Fariborz Jahanian725165f2009-05-18 21:05:18 +0000392}
393
Chris Lattner5caa3702009-05-08 06:58:22 +0000394/// SemaBuiltinAtomicOverloaded - We have a call to a function like
395/// __sync_fetch_and_add, which is an overloaded function based on the pointer
396/// type of its first argument. The main ActOnCallExpr routines have already
397/// promoted the types of arguments because all of these calls are prototyped as
398/// void(...).
399///
400/// This function goes through and does final semantic checking for these
401/// builtins,
John McCall60d7b3a2010-08-24 06:29:42 +0000402ExprResult
403Sema::SemaBuiltinAtomicOverloaded(ExprResult TheCallResult) {
Chandler Carruthd2014572010-07-09 18:59:35 +0000404 CallExpr *TheCall = (CallExpr *)TheCallResult.get();
Chris Lattner5caa3702009-05-08 06:58:22 +0000405 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
406 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
407
408 // Ensure that we have at least one argument to do type inference from.
Chandler Carruthd2014572010-07-09 18:59:35 +0000409 if (TheCall->getNumArgs() < 1) {
410 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
411 << 0 << 1 << TheCall->getNumArgs()
412 << TheCall->getCallee()->getSourceRange();
413 return ExprError();
414 }
Mike Stump1eb44332009-09-09 15:08:12 +0000415
Chris Lattner5caa3702009-05-08 06:58:22 +0000416 // Inspect the first argument of the atomic builtin. This should always be
417 // a pointer type, whose element is an integral scalar or pointer type.
418 // Because it is a pointer type, we don't have to worry about any implicit
419 // casts here.
Chandler Carruthd2014572010-07-09 18:59:35 +0000420 // FIXME: We don't allow floating point scalars as input.
Chris Lattner5caa3702009-05-08 06:58:22 +0000421 Expr *FirstArg = TheCall->getArg(0);
Chandler Carruthd2014572010-07-09 18:59:35 +0000422 if (!FirstArg->getType()->isPointerType()) {
423 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer)
424 << FirstArg->getType() << FirstArg->getSourceRange();
425 return ExprError();
426 }
Mike Stump1eb44332009-09-09 15:08:12 +0000427
Chandler Carruthd2014572010-07-09 18:59:35 +0000428 QualType ValType =
429 FirstArg->getType()->getAs<PointerType>()->getPointeeType();
Mike Stump1eb44332009-09-09 15:08:12 +0000430 if (!ValType->isIntegerType() && !ValType->isPointerType() &&
Chandler Carruthd2014572010-07-09 18:59:35 +0000431 !ValType->isBlockPointerType()) {
432 Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intptr)
433 << FirstArg->getType() << FirstArg->getSourceRange();
434 return ExprError();
435 }
Chris Lattner5caa3702009-05-08 06:58:22 +0000436
Chandler Carruth8d13d222010-07-18 20:54:12 +0000437 // The majority of builtins return a value, but a few have special return
438 // types, so allow them to override appropriately below.
439 QualType ResultType = ValType;
440
Chris Lattner5caa3702009-05-08 06:58:22 +0000441 // We need to figure out which concrete builtin this maps onto. For example,
442 // __sync_fetch_and_add with a 2 byte object turns into
443 // __sync_fetch_and_add_2.
444#define BUILTIN_ROW(x) \
445 { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \
446 Builtin::BI##x##_8, Builtin::BI##x##_16 }
Mike Stump1eb44332009-09-09 15:08:12 +0000447
Chris Lattner5caa3702009-05-08 06:58:22 +0000448 static const unsigned BuiltinIndices[][5] = {
449 BUILTIN_ROW(__sync_fetch_and_add),
450 BUILTIN_ROW(__sync_fetch_and_sub),
451 BUILTIN_ROW(__sync_fetch_and_or),
452 BUILTIN_ROW(__sync_fetch_and_and),
453 BUILTIN_ROW(__sync_fetch_and_xor),
Mike Stump1eb44332009-09-09 15:08:12 +0000454
Chris Lattner5caa3702009-05-08 06:58:22 +0000455 BUILTIN_ROW(__sync_add_and_fetch),
456 BUILTIN_ROW(__sync_sub_and_fetch),
457 BUILTIN_ROW(__sync_and_and_fetch),
458 BUILTIN_ROW(__sync_or_and_fetch),
459 BUILTIN_ROW(__sync_xor_and_fetch),
Mike Stump1eb44332009-09-09 15:08:12 +0000460
Chris Lattner5caa3702009-05-08 06:58:22 +0000461 BUILTIN_ROW(__sync_val_compare_and_swap),
462 BUILTIN_ROW(__sync_bool_compare_and_swap),
463 BUILTIN_ROW(__sync_lock_test_and_set),
464 BUILTIN_ROW(__sync_lock_release)
465 };
Mike Stump1eb44332009-09-09 15:08:12 +0000466#undef BUILTIN_ROW
467
Chris Lattner5caa3702009-05-08 06:58:22 +0000468 // Determine the index of the size.
469 unsigned SizeIndex;
Ken Dyck199c3d62010-01-11 17:06:35 +0000470 switch (Context.getTypeSizeInChars(ValType).getQuantity()) {
Chris Lattner5caa3702009-05-08 06:58:22 +0000471 case 1: SizeIndex = 0; break;
472 case 2: SizeIndex = 1; break;
473 case 4: SizeIndex = 2; break;
474 case 8: SizeIndex = 3; break;
475 case 16: SizeIndex = 4; break;
476 default:
Chandler Carruthd2014572010-07-09 18:59:35 +0000477 Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size)
478 << FirstArg->getType() << FirstArg->getSourceRange();
479 return ExprError();
Chris Lattner5caa3702009-05-08 06:58:22 +0000480 }
Mike Stump1eb44332009-09-09 15:08:12 +0000481
Chris Lattner5caa3702009-05-08 06:58:22 +0000482 // Each of these builtins has one pointer argument, followed by some number of
483 // values (0, 1 or 2) followed by a potentially empty varags list of stuff
484 // that we ignore. Find out which row of BuiltinIndices to read from as well
485 // as the number of fixed args.
Douglas Gregor7814e6d2009-09-12 00:22:50 +0000486 unsigned BuiltinID = FDecl->getBuiltinID();
Chris Lattner5caa3702009-05-08 06:58:22 +0000487 unsigned BuiltinIndex, NumFixed = 1;
488 switch (BuiltinID) {
489 default: assert(0 && "Unknown overloaded atomic builtin!");
490 case Builtin::BI__sync_fetch_and_add: BuiltinIndex = 0; break;
491 case Builtin::BI__sync_fetch_and_sub: BuiltinIndex = 1; break;
492 case Builtin::BI__sync_fetch_and_or: BuiltinIndex = 2; break;
493 case Builtin::BI__sync_fetch_and_and: BuiltinIndex = 3; break;
494 case Builtin::BI__sync_fetch_and_xor: BuiltinIndex = 4; break;
Mike Stump1eb44332009-09-09 15:08:12 +0000495
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000496 case Builtin::BI__sync_add_and_fetch: BuiltinIndex = 5; break;
497 case Builtin::BI__sync_sub_and_fetch: BuiltinIndex = 6; break;
498 case Builtin::BI__sync_and_and_fetch: BuiltinIndex = 7; break;
499 case Builtin::BI__sync_or_and_fetch: BuiltinIndex = 8; break;
500 case Builtin::BI__sync_xor_and_fetch: BuiltinIndex = 9; break;
Mike Stump1eb44332009-09-09 15:08:12 +0000501
Chris Lattner5caa3702009-05-08 06:58:22 +0000502 case Builtin::BI__sync_val_compare_and_swap:
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000503 BuiltinIndex = 10;
Chris Lattner5caa3702009-05-08 06:58:22 +0000504 NumFixed = 2;
505 break;
506 case Builtin::BI__sync_bool_compare_and_swap:
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000507 BuiltinIndex = 11;
Chris Lattner5caa3702009-05-08 06:58:22 +0000508 NumFixed = 2;
Chandler Carruth8d13d222010-07-18 20:54:12 +0000509 ResultType = Context.BoolTy;
Chris Lattner5caa3702009-05-08 06:58:22 +0000510 break;
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000511 case Builtin::BI__sync_lock_test_and_set: BuiltinIndex = 12; break;
Chris Lattner5caa3702009-05-08 06:58:22 +0000512 case Builtin::BI__sync_lock_release:
Daniel Dunbar7eff7c42010-03-25 17:13:09 +0000513 BuiltinIndex = 13;
Chris Lattner5caa3702009-05-08 06:58:22 +0000514 NumFixed = 0;
Chandler Carruth8d13d222010-07-18 20:54:12 +0000515 ResultType = Context.VoidTy;
Chris Lattner5caa3702009-05-08 06:58:22 +0000516 break;
517 }
Mike Stump1eb44332009-09-09 15:08:12 +0000518
Chris Lattner5caa3702009-05-08 06:58:22 +0000519 // Now that we know how many fixed arguments we expect, first check that we
520 // have at least that many.
Chandler Carruthd2014572010-07-09 18:59:35 +0000521 if (TheCall->getNumArgs() < 1+NumFixed) {
522 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
523 << 0 << 1+NumFixed << TheCall->getNumArgs()
524 << TheCall->getCallee()->getSourceRange();
525 return ExprError();
526 }
Mike Stump1eb44332009-09-09 15:08:12 +0000527
Chris Lattnere7ac0a92009-05-08 15:36:58 +0000528 // Get the decl for the concrete builtin from this, we can tell what the
529 // concrete integer type we should convert to is.
530 unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex];
531 const char *NewBuiltinName = Context.BuiltinInfo.GetName(NewBuiltinID);
532 IdentifierInfo *NewBuiltinII = PP.getIdentifierInfo(NewBuiltinName);
Mike Stump1eb44332009-09-09 15:08:12 +0000533 FunctionDecl *NewBuiltinDecl =
Chris Lattnere7ac0a92009-05-08 15:36:58 +0000534 cast<FunctionDecl>(LazilyCreateBuiltin(NewBuiltinII, NewBuiltinID,
535 TUScope, false, DRE->getLocStart()));
Chandler Carruthd2014572010-07-09 18:59:35 +0000536
John McCallf871d0c2010-08-07 06:22:56 +0000537 // The first argument --- the pointer --- has a fixed type; we
538 // deduce the types of the rest of the arguments accordingly. Walk
539 // the remaining arguments, converting them to the deduced value type.
Chris Lattner5caa3702009-05-08 06:58:22 +0000540 for (unsigned i = 0; i != NumFixed; ++i) {
541 Expr *Arg = TheCall->getArg(i+1);
Mike Stump1eb44332009-09-09 15:08:12 +0000542
Chris Lattner5caa3702009-05-08 06:58:22 +0000543 // If the argument is an implicit cast, then there was a promotion due to
544 // "...", just remove it now.
545 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) {
546 Arg = ICE->getSubExpr();
547 ICE->setSubExpr(0);
Chris Lattner5caa3702009-05-08 06:58:22 +0000548 TheCall->setArg(i+1, Arg);
549 }
Mike Stump1eb44332009-09-09 15:08:12 +0000550
Chris Lattner5caa3702009-05-08 06:58:22 +0000551 // GCC does an implicit conversion to the pointer or integer ValType. This
552 // can fail in some cases (1i -> int**), check for this error case now.
John McCall2de56d12010-08-25 11:45:40 +0000553 CastKind Kind = CK_Unknown;
John McCallf871d0c2010-08-07 06:22:56 +0000554 CXXCastPath BasePath;
Anders Carlsson5cf86ba2010-04-24 19:06:50 +0000555 if (CheckCastTypes(Arg->getSourceRange(), ValType, Arg, Kind, BasePath))
Chandler Carruthd2014572010-07-09 18:59:35 +0000556 return ExprError();
Mike Stump1eb44332009-09-09 15:08:12 +0000557
Chris Lattner5caa3702009-05-08 06:58:22 +0000558 // Okay, we have something that *can* be converted to the right type. Check
559 // to see if there is a potentially weird extension going on here. This can
560 // happen when you do an atomic operation on something like an char* and
561 // pass in 42. The 42 gets converted to char. This is even more strange
562 // for things like 45.123 -> char, etc.
Mike Stump1eb44332009-09-09 15:08:12 +0000563 // FIXME: Do this check.
John McCall5baba9d2010-08-25 10:28:54 +0000564 ImpCastExprToType(Arg, ValType, Kind, VK_RValue, &BasePath);
Chris Lattner5caa3702009-05-08 06:58:22 +0000565 TheCall->setArg(i+1, Arg);
566 }
Mike Stump1eb44332009-09-09 15:08:12 +0000567
Chris Lattner5caa3702009-05-08 06:58:22 +0000568 // Switch the DeclRefExpr to refer to the new decl.
569 DRE->setDecl(NewBuiltinDecl);
570 DRE->setType(NewBuiltinDecl->getType());
Mike Stump1eb44332009-09-09 15:08:12 +0000571
Chris Lattner5caa3702009-05-08 06:58:22 +0000572 // Set the callee in the CallExpr.
573 // FIXME: This leaks the original parens and implicit casts.
574 Expr *PromotedCall = DRE;
575 UsualUnaryConversions(PromotedCall);
576 TheCall->setCallee(PromotedCall);
Mike Stump1eb44332009-09-09 15:08:12 +0000577
Chandler Carruthdb4325b2010-07-18 07:23:17 +0000578 // Change the result type of the call to match the original value type. This
579 // is arbitrary, but the codegen for these builtins ins design to handle it
580 // gracefully.
Chandler Carruth8d13d222010-07-18 20:54:12 +0000581 TheCall->setType(ResultType);
Chandler Carruthd2014572010-07-09 18:59:35 +0000582
583 return move(TheCallResult);
Chris Lattner5caa3702009-05-08 06:58:22 +0000584}
585
586
Chris Lattner69039812009-02-18 06:01:06 +0000587/// CheckObjCString - Checks that the argument to the builtin
Anders Carlsson71993dd2007-08-17 05:31:46 +0000588/// CFString constructor is correct
Steve Narofffd942622009-04-13 20:26:29 +0000589/// Note: It might also make sense to do the UTF-16 conversion here (would
590/// simplify the backend).
Chris Lattner69039812009-02-18 06:01:06 +0000591bool Sema::CheckObjCString(Expr *Arg) {
Chris Lattner56f34942008-02-13 01:02:39 +0000592 Arg = Arg->IgnoreParenCasts();
Anders Carlsson71993dd2007-08-17 05:31:46 +0000593 StringLiteral *Literal = dyn_cast<StringLiteral>(Arg);
594
595 if (!Literal || Literal->isWide()) {
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000596 Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant)
597 << Arg->getSourceRange();
Anders Carlsson9cdc4d32007-08-17 15:44:17 +0000598 return true;
Anders Carlsson71993dd2007-08-17 05:31:46 +0000599 }
Mike Stump1eb44332009-09-09 15:08:12 +0000600
Benjamin Kramer2f4eaef2010-08-17 12:54:38 +0000601 size_t NulPos = Literal->getString().find('\0');
602 if (NulPos != llvm::StringRef::npos) {
603 Diag(getLocationOfStringLiteralByte(Literal, NulPos),
604 diag::warn_cfstring_literal_contains_nul_character)
605 << Arg->getSourceRange();
Daniel Dunbarf015b032009-09-22 10:03:52 +0000606 }
Fariborz Jahanian7da71022010-09-07 19:38:13 +0000607 if (Literal->containsNonAsciiOrNull()) {
608 llvm::StringRef String = Literal->getString();
609 unsigned NumBytes = String.size();
610 llvm::SmallVector<UTF16, 128> ToBuf(NumBytes);
611 const UTF8 *FromPtr = (UTF8 *)String.data();
612 UTF16 *ToPtr = &ToBuf[0];
613
614 ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
615 &ToPtr, ToPtr + NumBytes,
616 strictConversion);
617 // Check for conversion failure.
618 if (Result != conversionOK)
619 Diag(Arg->getLocStart(),
620 diag::warn_cfstring_truncated) << Arg->getSourceRange();
621 }
Anders Carlsson9cdc4d32007-08-17 15:44:17 +0000622 return false;
Chris Lattner59907c42007-08-10 20:18:51 +0000623}
624
Chris Lattnerc27c6652007-12-20 00:05:45 +0000625/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity.
626/// Emit an error and return true on failure, return false on success.
Chris Lattner925e60d2007-12-28 05:29:59 +0000627bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
628 Expr *Fn = TheCall->getCallee();
629 if (TheCall->getNumArgs() > 2) {
Chris Lattner2c21a072008-11-21 18:44:24 +0000630 Diag(TheCall->getArg(2)->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000631 diag::err_typecheck_call_too_many_args)
Eric Christopherccfa9632010-04-16 04:56:46 +0000632 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
633 << Fn->getSourceRange()
Mike Stump1eb44332009-09-09 15:08:12 +0000634 << SourceRange(TheCall->getArg(2)->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000635 (*(TheCall->arg_end()-1))->getLocEnd());
Chris Lattner30ce3442007-12-19 23:59:04 +0000636 return true;
637 }
Eli Friedman56f20ae2008-12-15 22:05:35 +0000638
639 if (TheCall->getNumArgs() < 2) {
Eric Christopherd77b9a22010-04-16 04:48:22 +0000640 return Diag(TheCall->getLocEnd(),
641 diag::err_typecheck_call_too_few_args_at_least)
642 << 0 /*function call*/ << 2 << TheCall->getNumArgs();
Eli Friedman56f20ae2008-12-15 22:05:35 +0000643 }
644
Chris Lattnerc27c6652007-12-20 00:05:45 +0000645 // Determine whether the current function is variadic or not.
Douglas Gregor9ea9bdb2010-03-01 23:15:13 +0000646 BlockScopeInfo *CurBlock = getCurBlock();
Chris Lattnerc27c6652007-12-20 00:05:45 +0000647 bool isVariadic;
Steve Naroffcd9c5142009-04-15 19:33:47 +0000648 if (CurBlock)
John McCallc71a4912010-06-04 19:02:56 +0000649 isVariadic = CurBlock->TheDecl->isVariadic();
Ted Kremenek9498d382010-04-29 16:49:01 +0000650 else if (FunctionDecl *FD = getCurFunctionDecl())
651 isVariadic = FD->isVariadic();
652 else
Argyrios Kyrtzidis53d0ea52008-06-28 06:07:14 +0000653 isVariadic = getCurMethodDecl()->isVariadic();
Mike Stump1eb44332009-09-09 15:08:12 +0000654
Chris Lattnerc27c6652007-12-20 00:05:45 +0000655 if (!isVariadic) {
Chris Lattner30ce3442007-12-19 23:59:04 +0000656 Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function);
657 return true;
658 }
Mike Stump1eb44332009-09-09 15:08:12 +0000659
Chris Lattner30ce3442007-12-19 23:59:04 +0000660 // Verify that the second argument to the builtin is the last argument of the
661 // current function or method.
662 bool SecondArgIsLastNamedArgument = false;
Anders Carlssone2c14102008-02-13 01:22:59 +0000663 const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts();
Mike Stump1eb44332009-09-09 15:08:12 +0000664
Anders Carlsson88cf2262008-02-11 04:20:54 +0000665 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) {
666 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) {
Chris Lattner30ce3442007-12-19 23:59:04 +0000667 // FIXME: This isn't correct for methods (results in bogus warning).
668 // Get the last formal in the current function.
Anders Carlsson88cf2262008-02-11 04:20:54 +0000669 const ParmVarDecl *LastArg;
Steve Naroffcd9c5142009-04-15 19:33:47 +0000670 if (CurBlock)
671 LastArg = *(CurBlock->TheDecl->param_end()-1);
672 else if (FunctionDecl *FD = getCurFunctionDecl())
Chris Lattner371f2582008-12-04 23:50:19 +0000673 LastArg = *(FD->param_end()-1);
Chris Lattner30ce3442007-12-19 23:59:04 +0000674 else
Argyrios Kyrtzidis53d0ea52008-06-28 06:07:14 +0000675 LastArg = *(getCurMethodDecl()->param_end()-1);
Chris Lattner30ce3442007-12-19 23:59:04 +0000676 SecondArgIsLastNamedArgument = PV == LastArg;
677 }
678 }
Mike Stump1eb44332009-09-09 15:08:12 +0000679
Chris Lattner30ce3442007-12-19 23:59:04 +0000680 if (!SecondArgIsLastNamedArgument)
Mike Stump1eb44332009-09-09 15:08:12 +0000681 Diag(TheCall->getArg(1)->getLocStart(),
Chris Lattner30ce3442007-12-19 23:59:04 +0000682 diag::warn_second_parameter_of_va_start_not_last_named_argument);
683 return false;
Eli Friedman6cfda232008-05-20 08:23:37 +0000684}
Chris Lattner30ce3442007-12-19 23:59:04 +0000685
Chris Lattner1b9a0792007-12-20 00:26:33 +0000686/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and
687/// friends. This is declared to take (...), so we have to check everything.
Chris Lattner925e60d2007-12-28 05:29:59 +0000688bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) {
689 if (TheCall->getNumArgs() < 2)
Chris Lattner2c21a072008-11-21 18:44:24 +0000690 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
Eric Christopherd77b9a22010-04-16 04:48:22 +0000691 << 0 << 2 << TheCall->getNumArgs()/*function call*/;
Chris Lattner925e60d2007-12-28 05:29:59 +0000692 if (TheCall->getNumArgs() > 2)
Mike Stump1eb44332009-09-09 15:08:12 +0000693 return Diag(TheCall->getArg(2)->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000694 diag::err_typecheck_call_too_many_args)
Eric Christopherccfa9632010-04-16 04:56:46 +0000695 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000696 << SourceRange(TheCall->getArg(2)->getLocStart(),
697 (*(TheCall->arg_end()-1))->getLocEnd());
Mike Stump1eb44332009-09-09 15:08:12 +0000698
Chris Lattner925e60d2007-12-28 05:29:59 +0000699 Expr *OrigArg0 = TheCall->getArg(0);
700 Expr *OrigArg1 = TheCall->getArg(1);
Douglas Gregorcde01732009-05-19 22:10:17 +0000701
Chris Lattner1b9a0792007-12-20 00:26:33 +0000702 // Do standard promotions between the two arguments, returning their common
703 // type.
Chris Lattner925e60d2007-12-28 05:29:59 +0000704 QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false);
Daniel Dunbar403bc2b2009-02-19 19:28:43 +0000705
706 // Make sure any conversions are pushed back into the call; this is
707 // type safe since unordered compare builtins are declared as "_Bool
708 // foo(...)".
709 TheCall->setArg(0, OrigArg0);
710 TheCall->setArg(1, OrigArg1);
Mike Stump1eb44332009-09-09 15:08:12 +0000711
Douglas Gregorcde01732009-05-19 22:10:17 +0000712 if (OrigArg0->isTypeDependent() || OrigArg1->isTypeDependent())
713 return false;
714
Chris Lattner1b9a0792007-12-20 00:26:33 +0000715 // If the common type isn't a real floating type, then the arguments were
716 // invalid for this operation.
717 if (!Res->isRealFloatingType())
Mike Stump1eb44332009-09-09 15:08:12 +0000718 return Diag(OrigArg0->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000719 diag::err_typecheck_call_invalid_ordered_compare)
Chris Lattnerd1625842008-11-24 06:25:27 +0000720 << OrigArg0->getType() << OrigArg1->getType()
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000721 << SourceRange(OrigArg0->getLocStart(), OrigArg1->getLocEnd());
Mike Stump1eb44332009-09-09 15:08:12 +0000722
Chris Lattner1b9a0792007-12-20 00:26:33 +0000723 return false;
724}
725
Benjamin Kramere771a7a2010-02-15 22:42:31 +0000726/// SemaBuiltinSemaBuiltinFPClassification - Handle functions like
727/// __builtin_isnan and friends. This is declared to take (...), so we have
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000728/// to check everything. We expect the last argument to be a floating point
729/// value.
730bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) {
731 if (TheCall->getNumArgs() < NumArgs)
Eli Friedman9ac6f622009-08-31 20:06:00 +0000732 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
Eric Christopherd77b9a22010-04-16 04:48:22 +0000733 << 0 << NumArgs << TheCall->getNumArgs()/*function call*/;
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000734 if (TheCall->getNumArgs() > NumArgs)
735 return Diag(TheCall->getArg(NumArgs)->getLocStart(),
Eli Friedman9ac6f622009-08-31 20:06:00 +0000736 diag::err_typecheck_call_too_many_args)
Eric Christopherccfa9632010-04-16 04:56:46 +0000737 << 0 /*function call*/ << NumArgs << TheCall->getNumArgs()
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000738 << SourceRange(TheCall->getArg(NumArgs)->getLocStart(),
Eli Friedman9ac6f622009-08-31 20:06:00 +0000739 (*(TheCall->arg_end()-1))->getLocEnd());
740
Benjamin Kramer3b1e26b2010-02-16 10:07:31 +0000741 Expr *OrigArg = TheCall->getArg(NumArgs-1);
Mike Stump1eb44332009-09-09 15:08:12 +0000742
Eli Friedman9ac6f622009-08-31 20:06:00 +0000743 if (OrigArg->isTypeDependent())
744 return false;
745
Chris Lattner81368fb2010-05-06 05:50:07 +0000746 // This operation requires a non-_Complex floating-point number.
Eli Friedman9ac6f622009-08-31 20:06:00 +0000747 if (!OrigArg->getType()->isRealFloatingType())
Mike Stump1eb44332009-09-09 15:08:12 +0000748 return Diag(OrigArg->getLocStart(),
Eli Friedman9ac6f622009-08-31 20:06:00 +0000749 diag::err_typecheck_call_invalid_unary_fp)
750 << OrigArg->getType() << OrigArg->getSourceRange();
Mike Stump1eb44332009-09-09 15:08:12 +0000751
Chris Lattner81368fb2010-05-06 05:50:07 +0000752 // If this is an implicit conversion from float -> double, remove it.
753 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(OrigArg)) {
754 Expr *CastArg = Cast->getSubExpr();
755 if (CastArg->getType()->isSpecificBuiltinType(BuiltinType::Float)) {
756 assert(Cast->getType()->isSpecificBuiltinType(BuiltinType::Double) &&
757 "promotion from float to double is the only expected cast here");
758 Cast->setSubExpr(0);
Chris Lattner81368fb2010-05-06 05:50:07 +0000759 TheCall->setArg(NumArgs-1, CastArg);
760 OrigArg = CastArg;
761 }
762 }
763
Eli Friedman9ac6f622009-08-31 20:06:00 +0000764 return false;
765}
766
Eli Friedmand38617c2008-05-14 19:38:39 +0000767/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector.
768// This is declared to take (...), so we have to check everything.
John McCall60d7b3a2010-08-24 06:29:42 +0000769ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) {
Nate Begeman37b6a572010-06-08 00:16:34 +0000770 if (TheCall->getNumArgs() < 2)
Sebastian Redl0eb23302009-01-19 00:08:26 +0000771 return ExprError(Diag(TheCall->getLocEnd(),
Eric Christopherd77b9a22010-04-16 04:48:22 +0000772 diag::err_typecheck_call_too_few_args_at_least)
Nate Begeman37b6a572010-06-08 00:16:34 +0000773 << 0 /*function call*/ << 2 << TheCall->getNumArgs()
Eric Christopherd77b9a22010-04-16 04:48:22 +0000774 << TheCall->getSourceRange());
Eli Friedmand38617c2008-05-14 19:38:39 +0000775
Nate Begeman37b6a572010-06-08 00:16:34 +0000776 // Determine which of the following types of shufflevector we're checking:
777 // 1) unary, vector mask: (lhs, mask)
778 // 2) binary, vector mask: (lhs, rhs, mask)
779 // 3) binary, scalar mask: (lhs, rhs, index, ..., index)
780 QualType resType = TheCall->getArg(0)->getType();
781 unsigned numElements = 0;
782
Douglas Gregorcde01732009-05-19 22:10:17 +0000783 if (!TheCall->getArg(0)->isTypeDependent() &&
784 !TheCall->getArg(1)->isTypeDependent()) {
Nate Begeman37b6a572010-06-08 00:16:34 +0000785 QualType LHSType = TheCall->getArg(0)->getType();
786 QualType RHSType = TheCall->getArg(1)->getType();
787
788 if (!LHSType->isVectorType() || !RHSType->isVectorType()) {
Douglas Gregorcde01732009-05-19 22:10:17 +0000789 Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector)
Mike Stump1eb44332009-09-09 15:08:12 +0000790 << SourceRange(TheCall->getArg(0)->getLocStart(),
Douglas Gregorcde01732009-05-19 22:10:17 +0000791 TheCall->getArg(1)->getLocEnd());
792 return ExprError();
793 }
Nate Begeman37b6a572010-06-08 00:16:34 +0000794
795 numElements = LHSType->getAs<VectorType>()->getNumElements();
796 unsigned numResElements = TheCall->getNumArgs() - 2;
Mike Stump1eb44332009-09-09 15:08:12 +0000797
Nate Begeman37b6a572010-06-08 00:16:34 +0000798 // Check to see if we have a call with 2 vector arguments, the unary shuffle
799 // with mask. If so, verify that RHS is an integer vector type with the
800 // same number of elts as lhs.
801 if (TheCall->getNumArgs() == 2) {
Douglas Gregorf6094622010-07-23 15:58:24 +0000802 if (!RHSType->hasIntegerRepresentation() ||
Nate Begeman37b6a572010-06-08 00:16:34 +0000803 RHSType->getAs<VectorType>()->getNumElements() != numElements)
804 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector)
805 << SourceRange(TheCall->getArg(1)->getLocStart(),
806 TheCall->getArg(1)->getLocEnd());
807 numResElements = numElements;
808 }
809 else if (!Context.hasSameUnqualifiedType(LHSType, RHSType)) {
Douglas Gregorcde01732009-05-19 22:10:17 +0000810 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector)
Mike Stump1eb44332009-09-09 15:08:12 +0000811 << SourceRange(TheCall->getArg(0)->getLocStart(),
Douglas Gregorcde01732009-05-19 22:10:17 +0000812 TheCall->getArg(1)->getLocEnd());
813 return ExprError();
Nate Begeman37b6a572010-06-08 00:16:34 +0000814 } else if (numElements != numResElements) {
815 QualType eltType = LHSType->getAs<VectorType>()->getElementType();
Chris Lattner788b0fd2010-06-23 06:00:24 +0000816 resType = Context.getVectorType(eltType, numResElements,
817 VectorType::NotAltiVec);
Douglas Gregorcde01732009-05-19 22:10:17 +0000818 }
Eli Friedmand38617c2008-05-14 19:38:39 +0000819 }
820
821 for (unsigned i = 2; i < TheCall->getNumArgs(); i++) {
Douglas Gregorcde01732009-05-19 22:10:17 +0000822 if (TheCall->getArg(i)->isTypeDependent() ||
823 TheCall->getArg(i)->isValueDependent())
824 continue;
825
Nate Begeman37b6a572010-06-08 00:16:34 +0000826 llvm::APSInt Result(32);
827 if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context))
828 return ExprError(Diag(TheCall->getLocStart(),
829 diag::err_shufflevector_nonconstant_argument)
830 << TheCall->getArg(i)->getSourceRange());
Sebastian Redl0eb23302009-01-19 00:08:26 +0000831
Chris Lattnerd1a0b6d2008-08-10 02:05:13 +0000832 if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2)
Sebastian Redl0eb23302009-01-19 00:08:26 +0000833 return ExprError(Diag(TheCall->getLocStart(),
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000834 diag::err_shufflevector_argument_too_large)
Sebastian Redl0eb23302009-01-19 00:08:26 +0000835 << TheCall->getArg(i)->getSourceRange());
Eli Friedmand38617c2008-05-14 19:38:39 +0000836 }
837
838 llvm::SmallVector<Expr*, 32> exprs;
839
Chris Lattnerd1a0b6d2008-08-10 02:05:13 +0000840 for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) {
Eli Friedmand38617c2008-05-14 19:38:39 +0000841 exprs.push_back(TheCall->getArg(i));
842 TheCall->setArg(i, 0);
843 }
844
Nate Begemana88dc302009-08-12 02:10:25 +0000845 return Owned(new (Context) ShuffleVectorExpr(Context, exprs.begin(),
Nate Begeman37b6a572010-06-08 00:16:34 +0000846 exprs.size(), resType,
Ted Kremenek8189cde2009-02-07 01:47:29 +0000847 TheCall->getCallee()->getLocStart(),
848 TheCall->getRParenLoc()));
Eli Friedmand38617c2008-05-14 19:38:39 +0000849}
Chris Lattner30ce3442007-12-19 23:59:04 +0000850
Daniel Dunbar4493f792008-07-21 22:59:13 +0000851/// SemaBuiltinPrefetch - Handle __builtin_prefetch.
852// This is declared to take (const void*, ...) and can take two
853// optional constant int args.
854bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) {
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000855 unsigned NumArgs = TheCall->getNumArgs();
Daniel Dunbar4493f792008-07-21 22:59:13 +0000856
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000857 if (NumArgs > 3)
Eric Christopherccfa9632010-04-16 04:56:46 +0000858 return Diag(TheCall->getLocEnd(),
859 diag::err_typecheck_call_too_many_args_at_most)
860 << 0 /*function call*/ << 3 << NumArgs
861 << TheCall->getSourceRange();
Daniel Dunbar4493f792008-07-21 22:59:13 +0000862
863 // Argument 0 is checked for us and the remaining arguments must be
864 // constant integers.
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000865 for (unsigned i = 1; i != NumArgs; ++i) {
Daniel Dunbar4493f792008-07-21 22:59:13 +0000866 Expr *Arg = TheCall->getArg(i);
Eric Christopher691ebc32010-04-17 02:26:23 +0000867
Eli Friedman9aef7262009-12-04 00:30:06 +0000868 llvm::APSInt Result;
Eric Christopher691ebc32010-04-17 02:26:23 +0000869 if (SemaBuiltinConstantArg(TheCall, i, Result))
870 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000871
Daniel Dunbar4493f792008-07-21 22:59:13 +0000872 // FIXME: gcc issues a warning and rewrites these to 0. These
873 // seems especially odd for the third argument since the default
874 // is 3.
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000875 if (i == 1) {
Eli Friedman9aef7262009-12-04 00:30:06 +0000876 if (Result.getLimitedValue() > 1)
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000877 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
Chris Lattner21fb98e2009-09-23 06:06:36 +0000878 << "0" << "1" << Arg->getSourceRange();
Daniel Dunbar4493f792008-07-21 22:59:13 +0000879 } else {
Eli Friedman9aef7262009-12-04 00:30:06 +0000880 if (Result.getLimitedValue() > 3)
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000881 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
Chris Lattner21fb98e2009-09-23 06:06:36 +0000882 << "0" << "3" << Arg->getSourceRange();
Daniel Dunbar4493f792008-07-21 22:59:13 +0000883 }
884 }
885
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000886 return false;
Daniel Dunbar4493f792008-07-21 22:59:13 +0000887}
888
Eric Christopher691ebc32010-04-17 02:26:23 +0000889/// SemaBuiltinConstantArg - Handle a check if argument ArgNum of CallExpr
890/// TheCall is a constant expression.
891bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
892 llvm::APSInt &Result) {
893 Expr *Arg = TheCall->getArg(ArgNum);
894 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts());
895 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl());
896
897 if (Arg->isTypeDependent() || Arg->isValueDependent()) return false;
898
899 if (!Arg->isIntegerConstantExpr(Result, Context))
900 return Diag(TheCall->getLocStart(), diag::err_constant_integer_arg_type)
Eric Christopher5e896552010-04-19 18:23:02 +0000901 << FDecl->getDeclName() << Arg->getSourceRange();
Eric Christopher691ebc32010-04-17 02:26:23 +0000902
Chris Lattner21fb98e2009-09-23 06:06:36 +0000903 return false;
904}
905
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000906/// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr,
907/// int type). This simply type checks that type is one of the defined
908/// constants (0-3).
Eric Christopherfee667f2009-12-23 03:49:37 +0000909// For compatability check 0-3, llvm only handles 0 and 2.
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000910bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) {
Eric Christopher691ebc32010-04-17 02:26:23 +0000911 llvm::APSInt Result;
912
913 // Check constant-ness first.
914 if (SemaBuiltinConstantArg(TheCall, 1, Result))
915 return true;
916
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000917 Expr *Arg = TheCall->getArg(1);
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000918 if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) {
Chris Lattnerfa25bbb2008-11-19 05:08:23 +0000919 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range)
920 << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
Daniel Dunbard5f8a4f2008-09-03 21:13:56 +0000921 }
922
923 return false;
924}
925
Eli Friedman586d6a82009-05-03 06:04:26 +0000926/// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val).
Eli Friedmand875fed2009-05-03 04:46:36 +0000927/// This checks that val is a constant 1.
928bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) {
929 Expr *Arg = TheCall->getArg(1);
Eric Christopher691ebc32010-04-17 02:26:23 +0000930 llvm::APSInt Result;
Douglas Gregorcde01732009-05-19 22:10:17 +0000931
Eric Christopher691ebc32010-04-17 02:26:23 +0000932 // TODO: This is less than ideal. Overload this to take a value.
933 if (SemaBuiltinConstantArg(TheCall, 1, Result))
934 return true;
935
936 if (Result != 1)
Eli Friedmand875fed2009-05-03 04:46:36 +0000937 return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val)
938 << SourceRange(Arg->getLocStart(), Arg->getLocEnd());
939
940 return false;
941}
942
Ted Kremenekd30ef872009-01-12 23:09:09 +0000943// Handle i > 1 ? "x" : "y", recursivelly
Ted Kremenek082d9362009-03-20 21:35:28 +0000944bool Sema::SemaCheckStringLiteral(const Expr *E, const CallExpr *TheCall,
945 bool HasVAListArg,
Ted Kremenek826a3452010-07-16 02:11:22 +0000946 unsigned format_idx, unsigned firstDataArg,
947 bool isPrintf) {
Ted Kremenek4fe64412010-09-09 03:51:39 +0000948 tryAgain:
Douglas Gregorcde01732009-05-19 22:10:17 +0000949 if (E->isTypeDependent() || E->isValueDependent())
950 return false;
Ted Kremenekd30ef872009-01-12 23:09:09 +0000951
952 switch (E->getStmtClass()) {
953 case Stmt::ConditionalOperatorClass: {
Ted Kremenek082d9362009-03-20 21:35:28 +0000954 const ConditionalOperator *C = cast<ConditionalOperator>(E);
Ted Kremenek826a3452010-07-16 02:11:22 +0000955 return SemaCheckStringLiteral(C->getTrueExpr(), TheCall, HasVAListArg,
956 format_idx, firstDataArg, isPrintf)
957 && SemaCheckStringLiteral(C->getRHS(), TheCall, HasVAListArg,
958 format_idx, firstDataArg, isPrintf);
Ted Kremenekd30ef872009-01-12 23:09:09 +0000959 }
960
Ted Kremenek95355bb2010-09-09 03:51:42 +0000961 case Stmt::IntegerLiteralClass:
962 // Technically -Wformat-nonliteral does not warn about this case.
963 // The behavior of printf and friends in this case is implementation
964 // dependent. Ideally if the format string cannot be null then
965 // it should have a 'nonnull' attribute in the function prototype.
966 return true;
967
Ted Kremenekd30ef872009-01-12 23:09:09 +0000968 case Stmt::ImplicitCastExprClass: {
Ted Kremenek4fe64412010-09-09 03:51:39 +0000969 E = cast<ImplicitCastExpr>(E)->getSubExpr();
970 goto tryAgain;
Ted Kremenekd30ef872009-01-12 23:09:09 +0000971 }
972
973 case Stmt::ParenExprClass: {
Ted Kremenek4fe64412010-09-09 03:51:39 +0000974 E = cast<ParenExpr>(E)->getSubExpr();
975 goto tryAgain;
Ted Kremenekd30ef872009-01-12 23:09:09 +0000976 }
Mike Stump1eb44332009-09-09 15:08:12 +0000977
Ted Kremenek082d9362009-03-20 21:35:28 +0000978 case Stmt::DeclRefExprClass: {
979 const DeclRefExpr *DR = cast<DeclRefExpr>(E);
Mike Stump1eb44332009-09-09 15:08:12 +0000980
Ted Kremenek082d9362009-03-20 21:35:28 +0000981 // As an exception, do not flag errors for variables binding to
982 // const string literals.
983 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
984 bool isConstant = false;
985 QualType T = DR->getType();
Ted Kremenekd30ef872009-01-12 23:09:09 +0000986
Ted Kremenek082d9362009-03-20 21:35:28 +0000987 if (const ArrayType *AT = Context.getAsArrayType(T)) {
988 isConstant = AT->getElementType().isConstant(Context);
Mike Stumpac5fc7c2009-08-04 21:02:39 +0000989 } else if (const PointerType *PT = T->getAs<PointerType>()) {
Mike Stump1eb44332009-09-09 15:08:12 +0000990 isConstant = T.isConstant(Context) &&
Ted Kremenek082d9362009-03-20 21:35:28 +0000991 PT->getPointeeType().isConstant(Context);
992 }
Mike Stump1eb44332009-09-09 15:08:12 +0000993
Ted Kremenek082d9362009-03-20 21:35:28 +0000994 if (isConstant) {
Sebastian Redl31310a22010-02-01 20:16:42 +0000995 if (const Expr *Init = VD->getAnyInitializer())
Ted Kremenek082d9362009-03-20 21:35:28 +0000996 return SemaCheckStringLiteral(Init, TheCall,
Ted Kremenek826a3452010-07-16 02:11:22 +0000997 HasVAListArg, format_idx, firstDataArg,
998 isPrintf);
Ted Kremenek082d9362009-03-20 21:35:28 +0000999 }
Mike Stump1eb44332009-09-09 15:08:12 +00001000
Anders Carlssond966a552009-06-28 19:55:58 +00001001 // For vprintf* functions (i.e., HasVAListArg==true), we add a
1002 // special check to see if the format string is a function parameter
1003 // of the function calling the printf function. If the function
1004 // has an attribute indicating it is a printf-like function, then we
1005 // should suppress warnings concerning non-literals being used in a call
1006 // to a vprintf function. For example:
1007 //
1008 // void
1009 // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){
1010 // va_list ap;
1011 // va_start(ap, fmt);
1012 // vprintf(fmt, ap); // Do NOT emit a warning about "fmt".
1013 // ...
1014 //
1015 //
1016 // FIXME: We don't have full attribute support yet, so just check to see
1017 // if the argument is a DeclRefExpr that references a parameter. We'll
1018 // add proper support for checking the attribute later.
1019 if (HasVAListArg)
1020 if (isa<ParmVarDecl>(VD))
1021 return true;
Ted Kremenek082d9362009-03-20 21:35:28 +00001022 }
Mike Stump1eb44332009-09-09 15:08:12 +00001023
Ted Kremenek082d9362009-03-20 21:35:28 +00001024 return false;
1025 }
Ted Kremenekd30ef872009-01-12 23:09:09 +00001026
Anders Carlsson8f031b32009-06-27 04:05:33 +00001027 case Stmt::CallExprClass: {
1028 const CallExpr *CE = cast<CallExpr>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00001029 if (const ImplicitCastExpr *ICE
Anders Carlsson8f031b32009-06-27 04:05:33 +00001030 = dyn_cast<ImplicitCastExpr>(CE->getCallee())) {
1031 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
1032 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
Argyrios Kyrtzidis40b598e2009-06-30 02:34:44 +00001033 if (const FormatArgAttr *FA = FD->getAttr<FormatArgAttr>()) {
Anders Carlsson8f031b32009-06-27 04:05:33 +00001034 unsigned ArgIndex = FA->getFormatIdx();
1035 const Expr *Arg = CE->getArg(ArgIndex - 1);
Mike Stump1eb44332009-09-09 15:08:12 +00001036
1037 return SemaCheckStringLiteral(Arg, TheCall, HasVAListArg,
Ted Kremenek826a3452010-07-16 02:11:22 +00001038 format_idx, firstDataArg, isPrintf);
Anders Carlsson8f031b32009-06-27 04:05:33 +00001039 }
1040 }
1041 }
1042 }
Mike Stump1eb44332009-09-09 15:08:12 +00001043
Anders Carlsson8f031b32009-06-27 04:05:33 +00001044 return false;
1045 }
Ted Kremenek082d9362009-03-20 21:35:28 +00001046 case Stmt::ObjCStringLiteralClass:
1047 case Stmt::StringLiteralClass: {
1048 const StringLiteral *StrE = NULL;
Mike Stump1eb44332009-09-09 15:08:12 +00001049
Ted Kremenek082d9362009-03-20 21:35:28 +00001050 if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E))
Ted Kremenekd30ef872009-01-12 23:09:09 +00001051 StrE = ObjCFExpr->getString();
1052 else
Ted Kremenek082d9362009-03-20 21:35:28 +00001053 StrE = cast<StringLiteral>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00001054
Ted Kremenekd30ef872009-01-12 23:09:09 +00001055 if (StrE) {
Ted Kremenek826a3452010-07-16 02:11:22 +00001056 CheckFormatString(StrE, E, TheCall, HasVAListArg, format_idx,
1057 firstDataArg, isPrintf);
Ted Kremenekd30ef872009-01-12 23:09:09 +00001058 return true;
1059 }
Mike Stump1eb44332009-09-09 15:08:12 +00001060
Ted Kremenekd30ef872009-01-12 23:09:09 +00001061 return false;
1062 }
Mike Stump1eb44332009-09-09 15:08:12 +00001063
Ted Kremenek082d9362009-03-20 21:35:28 +00001064 default:
1065 return false;
Ted Kremenekd30ef872009-01-12 23:09:09 +00001066 }
1067}
1068
Fariborz Jahaniane898f8a2009-05-21 18:48:51 +00001069void
Mike Stump1eb44332009-09-09 15:08:12 +00001070Sema::CheckNonNullArguments(const NonNullAttr *NonNull,
1071 const CallExpr *TheCall) {
Sean Huntcf807c42010-08-18 23:23:40 +00001072 for (NonNullAttr::args_iterator i = NonNull->args_begin(),
1073 e = NonNull->args_end();
Fariborz Jahaniane898f8a2009-05-21 18:48:51 +00001074 i != e; ++i) {
Chris Lattner12b97ff2009-05-25 18:23:36 +00001075 const Expr *ArgExpr = TheCall->getArg(*i);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001076 if (ArgExpr->isNullPointerConstant(Context,
Douglas Gregorce940492009-09-25 04:25:58 +00001077 Expr::NPC_ValueDependentIsNotNull))
Chris Lattner12b97ff2009-05-25 18:23:36 +00001078 Diag(TheCall->getCallee()->getLocStart(), diag::warn_null_arg)
1079 << ArgExpr->getSourceRange();
Fariborz Jahaniane898f8a2009-05-21 18:48:51 +00001080 }
1081}
Ted Kremenekd30ef872009-01-12 23:09:09 +00001082
Ted Kremenek826a3452010-07-16 02:11:22 +00001083/// CheckPrintfScanfArguments - Check calls to printf and scanf (and similar
1084/// functions) for correct use of format strings.
Chris Lattner59907c42007-08-10 20:18:51 +00001085void
Ted Kremenek826a3452010-07-16 02:11:22 +00001086Sema::CheckPrintfScanfArguments(const CallExpr *TheCall, bool HasVAListArg,
1087 unsigned format_idx, unsigned firstDataArg,
1088 bool isPrintf) {
1089
Ted Kremenek082d9362009-03-20 21:35:28 +00001090 const Expr *Fn = TheCall->getCallee();
Chris Lattner925e60d2007-12-28 05:29:59 +00001091
Sebastian Redl4a2614e2009-11-17 18:02:24 +00001092 // The way the format attribute works in GCC, the implicit this argument
1093 // of member functions is counted. However, it doesn't appear in our own
1094 // lists, so decrement format_idx in that case.
1095 if (isa<CXXMemberCallExpr>(TheCall)) {
1096 // Catch a format attribute mistakenly referring to the object argument.
1097 if (format_idx == 0)
1098 return;
1099 --format_idx;
1100 if(firstDataArg != 0)
1101 --firstDataArg;
1102 }
1103
Ted Kremenek826a3452010-07-16 02:11:22 +00001104 // CHECK: printf/scanf-like function is called with no format string.
Chris Lattner925e60d2007-12-28 05:29:59 +00001105 if (format_idx >= TheCall->getNumArgs()) {
Ted Kremenek826a3452010-07-16 02:11:22 +00001106 Diag(TheCall->getRParenLoc(), diag::warn_missing_format_string)
Chris Lattnerdcd5ef12008-11-19 05:27:50 +00001107 << Fn->getSourceRange();
Ted Kremenek71895b92007-08-14 17:39:48 +00001108 return;
1109 }
Mike Stump1eb44332009-09-09 15:08:12 +00001110
Ted Kremenek082d9362009-03-20 21:35:28 +00001111 const Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts();
Mike Stump1eb44332009-09-09 15:08:12 +00001112
Chris Lattner59907c42007-08-10 20:18:51 +00001113 // CHECK: format string is not a string literal.
Mike Stump1eb44332009-09-09 15:08:12 +00001114 //
Ted Kremenek71895b92007-08-14 17:39:48 +00001115 // Dynamically generated format strings are difficult to
1116 // automatically vet at compile time. Requiring that format strings
1117 // are string literals: (1) permits the checking of format strings by
1118 // the compiler and thereby (2) can practically remove the source of
1119 // many format string exploits.
Ted Kremenek7ff22b22008-06-16 18:00:42 +00001120
Mike Stump1eb44332009-09-09 15:08:12 +00001121 // Format string can be either ObjC string (e.g. @"%d") or
Ted Kremenek7ff22b22008-06-16 18:00:42 +00001122 // C string (e.g. "%d")
Mike Stump1eb44332009-09-09 15:08:12 +00001123 // ObjC string uses the same format specifiers as C string, so we can use
Ted Kremenek7ff22b22008-06-16 18:00:42 +00001124 // the same format string checking logic for both ObjC and C strings.
Chris Lattner1cd3e1f2009-04-29 04:49:34 +00001125 if (SemaCheckStringLiteral(OrigFormatExpr, TheCall, HasVAListArg, format_idx,
Ted Kremenek826a3452010-07-16 02:11:22 +00001126 firstDataArg, isPrintf))
Chris Lattner1cd3e1f2009-04-29 04:49:34 +00001127 return; // Literal format string found, check done!
Ted Kremenek7ff22b22008-06-16 18:00:42 +00001128
Chris Lattner655f1412009-04-29 04:59:47 +00001129 // If there are no arguments specified, warn with -Wformat-security, otherwise
1130 // warn only with -Wformat-nonliteral.
1131 if (TheCall->getNumArgs() == format_idx+1)
Mike Stump1eb44332009-09-09 15:08:12 +00001132 Diag(TheCall->getArg(format_idx)->getLocStart(),
Ted Kremenek826a3452010-07-16 02:11:22 +00001133 diag::warn_format_nonliteral_noargs)
Chris Lattner655f1412009-04-29 04:59:47 +00001134 << OrigFormatExpr->getSourceRange();
1135 else
Mike Stump1eb44332009-09-09 15:08:12 +00001136 Diag(TheCall->getArg(format_idx)->getLocStart(),
Ted Kremenek826a3452010-07-16 02:11:22 +00001137 diag::warn_format_nonliteral)
Chris Lattner655f1412009-04-29 04:59:47 +00001138 << OrigFormatExpr->getSourceRange();
Ted Kremenekd30ef872009-01-12 23:09:09 +00001139}
Ted Kremenek71895b92007-08-14 17:39:48 +00001140
Ted Kremeneke0e53132010-01-28 23:39:18 +00001141namespace {
Ted Kremenek826a3452010-07-16 02:11:22 +00001142class CheckFormatHandler : public analyze_format_string::FormatStringHandler {
1143protected:
Ted Kremeneke0e53132010-01-28 23:39:18 +00001144 Sema &S;
1145 const StringLiteral *FExpr;
1146 const Expr *OrigFormatExpr;
Ted Kremenek6ee76532010-03-25 03:59:12 +00001147 const unsigned FirstDataArg;
Ted Kremeneke0e53132010-01-28 23:39:18 +00001148 const unsigned NumDataArgs;
1149 const bool IsObjCLiteral;
1150 const char *Beg; // Start of format string.
Ted Kremenek0d277352010-01-29 01:06:55 +00001151 const bool HasVAListArg;
1152 const CallExpr *TheCall;
1153 unsigned FormatIdx;
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001154 llvm::BitVector CoveredArgs;
Ted Kremenekefaff192010-02-27 01:41:03 +00001155 bool usesPositionalArgs;
1156 bool atFirstArg;
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001157public:
Ted Kremenek826a3452010-07-16 02:11:22 +00001158 CheckFormatHandler(Sema &s, const StringLiteral *fexpr,
Ted Kremenek6ee76532010-03-25 03:59:12 +00001159 const Expr *origFormatExpr, unsigned firstDataArg,
Ted Kremeneke0e53132010-01-28 23:39:18 +00001160 unsigned numDataArgs, bool isObjCLiteral,
Ted Kremenek0d277352010-01-29 01:06:55 +00001161 const char *beg, bool hasVAListArg,
1162 const CallExpr *theCall, unsigned formatIdx)
Ted Kremeneke0e53132010-01-28 23:39:18 +00001163 : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr),
Ted Kremenek6ee76532010-03-25 03:59:12 +00001164 FirstDataArg(firstDataArg),
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001165 NumDataArgs(numDataArgs),
Ted Kremenek0d277352010-01-29 01:06:55 +00001166 IsObjCLiteral(isObjCLiteral), Beg(beg),
1167 HasVAListArg(hasVAListArg),
Ted Kremenekefaff192010-02-27 01:41:03 +00001168 TheCall(theCall), FormatIdx(formatIdx),
1169 usesPositionalArgs(false), atFirstArg(true) {
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001170 CoveredArgs.resize(numDataArgs);
1171 CoveredArgs.reset();
1172 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001173
Ted Kremenek07d161f2010-01-29 01:50:07 +00001174 void DoneProcessing();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001175
Ted Kremenek826a3452010-07-16 02:11:22 +00001176 void HandleIncompleteSpecifier(const char *startSpecifier,
1177 unsigned specifierLen);
1178
Ted Kremenekefaff192010-02-27 01:41:03 +00001179 virtual void HandleInvalidPosition(const char *startSpecifier,
1180 unsigned specifierLen,
Ted Kremenek826a3452010-07-16 02:11:22 +00001181 analyze_format_string::PositionContext p);
Ted Kremenekefaff192010-02-27 01:41:03 +00001182
1183 virtual void HandleZeroPosition(const char *startPos, unsigned posLen);
1184
Ted Kremeneke0e53132010-01-28 23:39:18 +00001185 void HandleNullChar(const char *nullCharacter);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001186
Ted Kremenek826a3452010-07-16 02:11:22 +00001187protected:
Ted Kremenekc09b6a52010-07-19 21:25:57 +00001188 bool HandleInvalidConversionSpecifier(unsigned argIndex, SourceLocation Loc,
1189 const char *startSpec,
1190 unsigned specifierLen,
1191 const char *csStart, unsigned csLen);
1192
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001193 SourceRange getFormatStringRange();
Ted Kremenek826a3452010-07-16 02:11:22 +00001194 CharSourceRange getSpecifierRange(const char *startSpecifier,
1195 unsigned specifierLen);
Ted Kremeneke0e53132010-01-28 23:39:18 +00001196 SourceLocation getLocationOfByte(const char *x);
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001197
Ted Kremenek0d277352010-01-29 01:06:55 +00001198 const Expr *getDataArg(unsigned i) const;
Ted Kremenek666a1972010-07-26 19:45:42 +00001199
1200 bool CheckNumArgs(const analyze_format_string::FormatSpecifier &FS,
1201 const analyze_format_string::ConversionSpecifier &CS,
1202 const char *startSpecifier, unsigned specifierLen,
1203 unsigned argIndex);
Ted Kremeneke0e53132010-01-28 23:39:18 +00001204};
1205}
1206
Ted Kremenek826a3452010-07-16 02:11:22 +00001207SourceRange CheckFormatHandler::getFormatStringRange() {
Ted Kremeneke0e53132010-01-28 23:39:18 +00001208 return OrigFormatExpr->getSourceRange();
1209}
1210
Ted Kremenek826a3452010-07-16 02:11:22 +00001211CharSourceRange CheckFormatHandler::
1212getSpecifierRange(const char *startSpecifier, unsigned specifierLen) {
Tom Care45f9b7e2010-06-21 21:21:01 +00001213 SourceLocation Start = getLocationOfByte(startSpecifier);
1214 SourceLocation End = getLocationOfByte(startSpecifier + specifierLen - 1);
1215
1216 // Advance the end SourceLocation by one due to half-open ranges.
1217 End = End.getFileLocWithOffset(1);
1218
1219 return CharSourceRange::getCharRange(Start, End);
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001220}
1221
Ted Kremenek826a3452010-07-16 02:11:22 +00001222SourceLocation CheckFormatHandler::getLocationOfByte(const char *x) {
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001223 return S.getLocationOfStringLiteralByte(FExpr, x - Beg);
Ted Kremeneke0e53132010-01-28 23:39:18 +00001224}
1225
Ted Kremenek826a3452010-07-16 02:11:22 +00001226void CheckFormatHandler::HandleIncompleteSpecifier(const char *startSpecifier,
1227 unsigned specifierLen){
Ted Kremenek808015a2010-01-29 03:16:21 +00001228 SourceLocation Loc = getLocationOfByte(startSpecifier);
1229 S.Diag(Loc, diag::warn_printf_incomplete_specifier)
Ted Kremenek826a3452010-07-16 02:11:22 +00001230 << getSpecifierRange(startSpecifier, specifierLen);
Ted Kremenek808015a2010-01-29 03:16:21 +00001231}
1232
Ted Kremenekefaff192010-02-27 01:41:03 +00001233void
Ted Kremenek826a3452010-07-16 02:11:22 +00001234CheckFormatHandler::HandleInvalidPosition(const char *startPos, unsigned posLen,
1235 analyze_format_string::PositionContext p) {
Ted Kremenekefaff192010-02-27 01:41:03 +00001236 SourceLocation Loc = getLocationOfByte(startPos);
Ted Kremenek826a3452010-07-16 02:11:22 +00001237 S.Diag(Loc, diag::warn_format_invalid_positional_specifier)
1238 << (unsigned) p << getSpecifierRange(startPos, posLen);
Ted Kremenekefaff192010-02-27 01:41:03 +00001239}
1240
Ted Kremenek826a3452010-07-16 02:11:22 +00001241void CheckFormatHandler::HandleZeroPosition(const char *startPos,
Ted Kremenekefaff192010-02-27 01:41:03 +00001242 unsigned posLen) {
1243 SourceLocation Loc = getLocationOfByte(startPos);
Ted Kremenek826a3452010-07-16 02:11:22 +00001244 S.Diag(Loc, diag::warn_format_zero_positional_specifier)
1245 << getSpecifierRange(startPos, posLen);
Ted Kremenekefaff192010-02-27 01:41:03 +00001246}
1247
Ted Kremenek826a3452010-07-16 02:11:22 +00001248void CheckFormatHandler::HandleNullChar(const char *nullCharacter) {
1249 // The presence of a null character is likely an error.
1250 S.Diag(getLocationOfByte(nullCharacter),
1251 diag::warn_printf_format_string_contains_null_char)
1252 << getFormatStringRange();
1253}
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001254
Ted Kremenek826a3452010-07-16 02:11:22 +00001255const Expr *CheckFormatHandler::getDataArg(unsigned i) const {
1256 return TheCall->getArg(FirstDataArg + i);
1257}
1258
1259void CheckFormatHandler::DoneProcessing() {
1260 // Does the number of data arguments exceed the number of
1261 // format conversions in the format string?
1262 if (!HasVAListArg) {
1263 // Find any arguments that weren't covered.
1264 CoveredArgs.flip();
1265 signed notCoveredArg = CoveredArgs.find_first();
1266 if (notCoveredArg >= 0) {
1267 assert((unsigned)notCoveredArg < NumDataArgs);
1268 S.Diag(getDataArg((unsigned) notCoveredArg)->getLocStart(),
1269 diag::warn_printf_data_arg_not_used)
1270 << getFormatStringRange();
1271 }
1272 }
1273}
1274
Ted Kremenekc09b6a52010-07-19 21:25:57 +00001275bool
1276CheckFormatHandler::HandleInvalidConversionSpecifier(unsigned argIndex,
1277 SourceLocation Loc,
1278 const char *startSpec,
1279 unsigned specifierLen,
1280 const char *csStart,
1281 unsigned csLen) {
1282
1283 bool keepGoing = true;
1284 if (argIndex < NumDataArgs) {
1285 // Consider the argument coverered, even though the specifier doesn't
1286 // make sense.
1287 CoveredArgs.set(argIndex);
1288 }
1289 else {
1290 // If argIndex exceeds the number of data arguments we
1291 // don't issue a warning because that is just a cascade of warnings (and
1292 // they may have intended '%%' anyway). We don't want to continue processing
1293 // the format string after this point, however, as we will like just get
1294 // gibberish when trying to match arguments.
1295 keepGoing = false;
1296 }
1297
1298 S.Diag(Loc, diag::warn_format_invalid_conversion)
1299 << llvm::StringRef(csStart, csLen)
1300 << getSpecifierRange(startSpec, specifierLen);
1301
1302 return keepGoing;
1303}
1304
Ted Kremenek666a1972010-07-26 19:45:42 +00001305bool
1306CheckFormatHandler::CheckNumArgs(
1307 const analyze_format_string::FormatSpecifier &FS,
1308 const analyze_format_string::ConversionSpecifier &CS,
1309 const char *startSpecifier, unsigned specifierLen, unsigned argIndex) {
1310
1311 if (argIndex >= NumDataArgs) {
1312 if (FS.usesPositionalArg()) {
1313 S.Diag(getLocationOfByte(CS.getStart()),
1314 diag::warn_printf_positional_arg_exceeds_data_args)
1315 << (argIndex+1) << NumDataArgs
1316 << getSpecifierRange(startSpecifier, specifierLen);
1317 }
1318 else {
1319 S.Diag(getLocationOfByte(CS.getStart()),
1320 diag::warn_printf_insufficient_data_args)
1321 << getSpecifierRange(startSpecifier, specifierLen);
1322 }
1323
1324 return false;
1325 }
1326 return true;
1327}
1328
Ted Kremenek826a3452010-07-16 02:11:22 +00001329//===--- CHECK: Printf format string checking ------------------------------===//
1330
1331namespace {
1332class CheckPrintfHandler : public CheckFormatHandler {
1333public:
1334 CheckPrintfHandler(Sema &s, const StringLiteral *fexpr,
1335 const Expr *origFormatExpr, unsigned firstDataArg,
1336 unsigned numDataArgs, bool isObjCLiteral,
1337 const char *beg, bool hasVAListArg,
1338 const CallExpr *theCall, unsigned formatIdx)
1339 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
1340 numDataArgs, isObjCLiteral, beg, hasVAListArg,
1341 theCall, formatIdx) {}
1342
1343
1344 bool HandleInvalidPrintfConversionSpecifier(
1345 const analyze_printf::PrintfSpecifier &FS,
1346 const char *startSpecifier,
1347 unsigned specifierLen);
1348
1349 bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS,
1350 const char *startSpecifier,
1351 unsigned specifierLen);
1352
1353 bool HandleAmount(const analyze_format_string::OptionalAmount &Amt, unsigned k,
1354 const char *startSpecifier, unsigned specifierLen);
1355 void HandleInvalidAmount(const analyze_printf::PrintfSpecifier &FS,
1356 const analyze_printf::OptionalAmount &Amt,
1357 unsigned type,
1358 const char *startSpecifier, unsigned specifierLen);
1359 void HandleFlag(const analyze_printf::PrintfSpecifier &FS,
1360 const analyze_printf::OptionalFlag &flag,
1361 const char *startSpecifier, unsigned specifierLen);
1362 void HandleIgnoredFlag(const analyze_printf::PrintfSpecifier &FS,
1363 const analyze_printf::OptionalFlag &ignoredFlag,
1364 const analyze_printf::OptionalFlag &flag,
1365 const char *startSpecifier, unsigned specifierLen);
1366};
1367}
1368
1369bool CheckPrintfHandler::HandleInvalidPrintfConversionSpecifier(
1370 const analyze_printf::PrintfSpecifier &FS,
1371 const char *startSpecifier,
1372 unsigned specifierLen) {
Ted Kremenek6ecb9502010-07-20 20:04:27 +00001373 const analyze_printf::PrintfConversionSpecifier &CS =
Ted Kremenekc09b6a52010-07-19 21:25:57 +00001374 FS.getConversionSpecifier();
Ted Kremenek826a3452010-07-16 02:11:22 +00001375
Ted Kremenekc09b6a52010-07-19 21:25:57 +00001376 return HandleInvalidConversionSpecifier(FS.getArgIndex(),
1377 getLocationOfByte(CS.getStart()),
1378 startSpecifier, specifierLen,
1379 CS.getStart(), CS.getLength());
Ted Kremenek26ac2e02010-01-29 02:40:24 +00001380}
1381
Ted Kremenek826a3452010-07-16 02:11:22 +00001382bool CheckPrintfHandler::HandleAmount(
1383 const analyze_format_string::OptionalAmount &Amt,
1384 unsigned k, const char *startSpecifier,
1385 unsigned specifierLen) {
Ted Kremenek0d277352010-01-29 01:06:55 +00001386
1387 if (Amt.hasDataArgument()) {
Ted Kremenek0d277352010-01-29 01:06:55 +00001388 if (!HasVAListArg) {
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001389 unsigned argIndex = Amt.getArgIndex();
1390 if (argIndex >= NumDataArgs) {
Ted Kremenekefaff192010-02-27 01:41:03 +00001391 S.Diag(getLocationOfByte(Amt.getStart()),
1392 diag::warn_printf_asterisk_missing_arg)
Ted Kremenek826a3452010-07-16 02:11:22 +00001393 << k << getSpecifierRange(startSpecifier, specifierLen);
Ted Kremenek0d277352010-01-29 01:06:55 +00001394 // Don't do any more checking. We will just emit
1395 // spurious errors.
1396 return false;
1397 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001398
Ted Kremenek0d277352010-01-29 01:06:55 +00001399 // Type check the data argument. It should be an 'int'.
Ted Kremenek31f8e322010-01-29 23:32:22 +00001400 // Although not in conformance with C99, we also allow the argument to be
1401 // an 'unsigned int' as that is a reasonably safe case. GCC also
1402 // doesn't emit a warning for that case.
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001403 CoveredArgs.set(argIndex);
1404 const Expr *Arg = getDataArg(argIndex);
Ted Kremenek0d277352010-01-29 01:06:55 +00001405 QualType T = Arg->getType();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001406
1407 const analyze_printf::ArgTypeResult &ATR = Amt.getArgType(S.Context);
1408 assert(ATR.isValid());
1409
1410 if (!ATR.matchesType(S.Context, T)) {
Ted Kremenekefaff192010-02-27 01:41:03 +00001411 S.Diag(getLocationOfByte(Amt.getStart()),
1412 diag::warn_printf_asterisk_wrong_type)
1413 << k
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001414 << ATR.getRepresentativeType(S.Context) << T
Ted Kremenek826a3452010-07-16 02:11:22 +00001415 << getSpecifierRange(startSpecifier, specifierLen)
Ted Kremenekd635c5f2010-01-30 00:49:51 +00001416 << Arg->getSourceRange();
Ted Kremenek0d277352010-01-29 01:06:55 +00001417 // Don't do any more checking. We will just emit
1418 // spurious errors.
1419 return false;
1420 }
1421 }
1422 }
1423 return true;
1424}
Ted Kremenek0d277352010-01-29 01:06:55 +00001425
Tom Caree4ee9662010-06-17 19:00:27 +00001426void CheckPrintfHandler::HandleInvalidAmount(
Ted Kremenek826a3452010-07-16 02:11:22 +00001427 const analyze_printf::PrintfSpecifier &FS,
Tom Caree4ee9662010-06-17 19:00:27 +00001428 const analyze_printf::OptionalAmount &Amt,
1429 unsigned type,
1430 const char *startSpecifier,
1431 unsigned specifierLen) {
Ted Kremenek6ecb9502010-07-20 20:04:27 +00001432 const analyze_printf::PrintfConversionSpecifier &CS =
1433 FS.getConversionSpecifier();
Tom Caree4ee9662010-06-17 19:00:27 +00001434 switch (Amt.getHowSpecified()) {
1435 case analyze_printf::OptionalAmount::Constant:
1436 S.Diag(getLocationOfByte(Amt.getStart()),
1437 diag::warn_printf_nonsensical_optional_amount)
1438 << type
1439 << CS.toString()
Ted Kremenek826a3452010-07-16 02:11:22 +00001440 << getSpecifierRange(startSpecifier, specifierLen)
1441 << FixItHint::CreateRemoval(getSpecifierRange(Amt.getStart(),
Tom Caree4ee9662010-06-17 19:00:27 +00001442 Amt.getConstantLength()));
1443 break;
1444
1445 default:
1446 S.Diag(getLocationOfByte(Amt.getStart()),
1447 diag::warn_printf_nonsensical_optional_amount)
1448 << type
1449 << CS.toString()
Ted Kremenek826a3452010-07-16 02:11:22 +00001450 << getSpecifierRange(startSpecifier, specifierLen);
Tom Caree4ee9662010-06-17 19:00:27 +00001451 break;
1452 }
1453}
1454
Ted Kremenek826a3452010-07-16 02:11:22 +00001455void CheckPrintfHandler::HandleFlag(const analyze_printf::PrintfSpecifier &FS,
Tom Caree4ee9662010-06-17 19:00:27 +00001456 const analyze_printf::OptionalFlag &flag,
1457 const char *startSpecifier,
1458 unsigned specifierLen) {
1459 // Warn about pointless flag with a fixit removal.
Ted Kremenek6ecb9502010-07-20 20:04:27 +00001460 const analyze_printf::PrintfConversionSpecifier &CS =
1461 FS.getConversionSpecifier();
Tom Caree4ee9662010-06-17 19:00:27 +00001462 S.Diag(getLocationOfByte(flag.getPosition()),
1463 diag::warn_printf_nonsensical_flag)
1464 << flag.toString() << CS.toString()
Ted Kremenek826a3452010-07-16 02:11:22 +00001465 << getSpecifierRange(startSpecifier, specifierLen)
1466 << FixItHint::CreateRemoval(getSpecifierRange(flag.getPosition(), 1));
Tom Caree4ee9662010-06-17 19:00:27 +00001467}
1468
1469void CheckPrintfHandler::HandleIgnoredFlag(
Ted Kremenek826a3452010-07-16 02:11:22 +00001470 const analyze_printf::PrintfSpecifier &FS,
Tom Caree4ee9662010-06-17 19:00:27 +00001471 const analyze_printf::OptionalFlag &ignoredFlag,
1472 const analyze_printf::OptionalFlag &flag,
1473 const char *startSpecifier,
1474 unsigned specifierLen) {
1475 // Warn about ignored flag with a fixit removal.
1476 S.Diag(getLocationOfByte(ignoredFlag.getPosition()),
1477 diag::warn_printf_ignored_flag)
1478 << ignoredFlag.toString() << flag.toString()
Ted Kremenek826a3452010-07-16 02:11:22 +00001479 << getSpecifierRange(startSpecifier, specifierLen)
1480 << FixItHint::CreateRemoval(getSpecifierRange(
Tom Caree4ee9662010-06-17 19:00:27 +00001481 ignoredFlag.getPosition(), 1));
1482}
1483
Ted Kremeneke0e53132010-01-28 23:39:18 +00001484bool
Ted Kremenek826a3452010-07-16 02:11:22 +00001485CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier
Ted Kremenek5c41ee82010-02-11 09:27:41 +00001486 &FS,
Ted Kremeneke0e53132010-01-28 23:39:18 +00001487 const char *startSpecifier,
1488 unsigned specifierLen) {
1489
Ted Kremenek6ecb9502010-07-20 20:04:27 +00001490 using namespace analyze_format_string;
Ted Kremenekefaff192010-02-27 01:41:03 +00001491 using namespace analyze_printf;
Ted Kremenek6ecb9502010-07-20 20:04:27 +00001492 const PrintfConversionSpecifier &CS = FS.getConversionSpecifier();
Ted Kremeneke0e53132010-01-28 23:39:18 +00001493
Ted Kremenekbaa40062010-07-19 22:01:06 +00001494 if (FS.consumesDataArgument()) {
1495 if (atFirstArg) {
1496 atFirstArg = false;
1497 usesPositionalArgs = FS.usesPositionalArg();
1498 }
1499 else if (usesPositionalArgs != FS.usesPositionalArg()) {
1500 // Cannot mix-and-match positional and non-positional arguments.
1501 S.Diag(getLocationOfByte(CS.getStart()),
1502 diag::warn_format_mix_positional_nonpositional_args)
1503 << getSpecifierRange(startSpecifier, specifierLen);
1504 return false;
1505 }
Ted Kremenek0d277352010-01-29 01:06:55 +00001506 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001507
Ted Kremenekefaff192010-02-27 01:41:03 +00001508 // First check if the field width, precision, and conversion specifier
1509 // have matching data arguments.
1510 if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0,
1511 startSpecifier, specifierLen)) {
1512 return false;
1513 }
1514
1515 if (!HandleAmount(FS.getPrecision(), /* precision */ 1,
1516 startSpecifier, specifierLen)) {
Ted Kremenek0d277352010-01-29 01:06:55 +00001517 return false;
1518 }
1519
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001520 if (!CS.consumesDataArgument()) {
1521 // FIXME: Technically specifying a precision or field width here
1522 // makes no sense. Worth issuing a warning at some point.
Ted Kremenek0e5675d2010-02-10 02:16:30 +00001523 return true;
Ted Kremenekf88c8e02010-01-29 20:55:36 +00001524 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001525
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001526 // Consume the argument.
1527 unsigned argIndex = FS.getArgIndex();
Ted Kremeneke3fc5472010-02-27 08:34:51 +00001528 if (argIndex < NumDataArgs) {
1529 // The check to see if the argIndex is valid will come later.
1530 // We set the bit here because we may exit early from this
1531 // function if we encounter some other error.
1532 CoveredArgs.set(argIndex);
1533 }
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001534
1535 // Check for using an Objective-C specific conversion specifier
1536 // in a non-ObjC literal.
1537 if (!IsObjCLiteral && CS.isObjCArg()) {
Ted Kremenek826a3452010-07-16 02:11:22 +00001538 return HandleInvalidPrintfConversionSpecifier(FS, startSpecifier,
1539 specifierLen);
Ted Kremenek7f70dc82010-02-26 19:18:41 +00001540 }
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001541
Tom Caree4ee9662010-06-17 19:00:27 +00001542 // Check for invalid use of field width
1543 if (!FS.hasValidFieldWidth()) {
Tom Care45f9b7e2010-06-21 21:21:01 +00001544 HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 0,
Tom Caree4ee9662010-06-17 19:00:27 +00001545 startSpecifier, specifierLen);
1546 }
1547
1548 // Check for invalid use of precision
1549 if (!FS.hasValidPrecision()) {
1550 HandleInvalidAmount(FS, FS.getPrecision(), /* precision */ 1,
1551 startSpecifier, specifierLen);
1552 }
1553
1554 // Check each flag does not conflict with any other component.
1555 if (!FS.hasValidLeadingZeros())
1556 HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen);
1557 if (!FS.hasValidPlusPrefix())
1558 HandleFlag(FS, FS.hasPlusPrefix(), startSpecifier, specifierLen);
Tom Care45f9b7e2010-06-21 21:21:01 +00001559 if (!FS.hasValidSpacePrefix())
1560 HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen);
Tom Caree4ee9662010-06-17 19:00:27 +00001561 if (!FS.hasValidAlternativeForm())
1562 HandleFlag(FS, FS.hasAlternativeForm(), startSpecifier, specifierLen);
1563 if (!FS.hasValidLeftJustified())
1564 HandleFlag(FS, FS.isLeftJustified(), startSpecifier, specifierLen);
1565
1566 // Check that flags are not ignored by another flag
Tom Care45f9b7e2010-06-21 21:21:01 +00001567 if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+'
1568 HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(),
1569 startSpecifier, specifierLen);
Tom Caree4ee9662010-06-17 19:00:27 +00001570 if (FS.hasLeadingZeros() && FS.isLeftJustified()) // '0' ignored by '-'
1571 HandleIgnoredFlag(FS, FS.hasLeadingZeros(), FS.isLeftJustified(),
1572 startSpecifier, specifierLen);
1573
1574 // Check the length modifier is valid with the given conversion specifier.
1575 const LengthModifier &LM = FS.getLengthModifier();
1576 if (!FS.hasValidLengthModifier())
1577 S.Diag(getLocationOfByte(LM.getStart()),
Ted Kremenek649aecf2010-07-20 20:03:43 +00001578 diag::warn_format_nonsensical_length)
Tom Caree4ee9662010-06-17 19:00:27 +00001579 << LM.toString() << CS.toString()
Ted Kremenek826a3452010-07-16 02:11:22 +00001580 << getSpecifierRange(startSpecifier, specifierLen)
1581 << FixItHint::CreateRemoval(getSpecifierRange(LM.getStart(),
Tom Caree4ee9662010-06-17 19:00:27 +00001582 LM.getLength()));
1583
1584 // Are we using '%n'?
Ted Kremenek35d353b2010-07-20 20:04:10 +00001585 if (CS.getKind() == ConversionSpecifier::nArg) {
Tom Caree4ee9662010-06-17 19:00:27 +00001586 // Issue a warning about this being a possible security issue.
Ted Kremeneke82d8042010-01-29 01:35:25 +00001587 S.Diag(getLocationOfByte(CS.getStart()), diag::warn_printf_write_back)
Ted Kremenek826a3452010-07-16 02:11:22 +00001588 << getSpecifierRange(startSpecifier, specifierLen);
Ted Kremeneke82d8042010-01-29 01:35:25 +00001589 // Continue checking the other format specifiers.
1590 return true;
1591 }
Ted Kremenek5c41ee82010-02-11 09:27:41 +00001592
Ted Kremenekda51f0d2010-01-29 01:43:31 +00001593 // The remaining checks depend on the data arguments.
1594 if (HasVAListArg)
1595 return true;
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001596
Ted Kremenek666a1972010-07-26 19:45:42 +00001597 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
Ted Kremenekda51f0d2010-01-29 01:43:31 +00001598 return false;
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001599
Michael J. Spencer96827eb2010-07-27 04:46:02 +00001600 // Now type check the data expression that matches the
1601 // format specifier.
1602 const Expr *Ex = getDataArg(argIndex);
1603 const analyze_printf::ArgTypeResult &ATR = FS.getArgType(S.Context);
1604 if (ATR.isValid() && !ATR.matchesType(S.Context, Ex->getType())) {
1605 // Check if we didn't match because of an implicit cast from a 'char'
1606 // or 'short' to an 'int'. This is done because printf is a varargs
1607 // function.
1608 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Ex))
1609 if (ICE->getType() == S.Context.IntTy)
1610 if (ATR.matchesType(S.Context, ICE->getSubExpr()->getType()))
1611 return true;
1612
1613 // We may be able to offer a FixItHint if it is a supported type.
1614 PrintfSpecifier fixedFS = FS;
1615 bool success = fixedFS.fixType(Ex->getType());
1616
1617 if (success) {
1618 // Get the fix string from the fixed format specifier
1619 llvm::SmallString<128> buf;
1620 llvm::raw_svector_ostream os(buf);
1621 fixedFS.toString(os);
1622
Ted Kremenek9325eaf2010-08-24 22:24:51 +00001623 // FIXME: getRepresentativeType() perhaps should return a string
1624 // instead of a QualType to better handle when the representative
1625 // type is 'wint_t' (which is defined in the system headers).
Michael J. Spencer96827eb2010-07-27 04:46:02 +00001626 S.Diag(getLocationOfByte(CS.getStart()),
1627 diag::warn_printf_conversion_argument_type_mismatch)
1628 << ATR.getRepresentativeType(S.Context) << Ex->getType()
1629 << getSpecifierRange(startSpecifier, specifierLen)
1630 << Ex->getSourceRange()
1631 << FixItHint::CreateReplacement(
1632 getSpecifierRange(startSpecifier, specifierLen),
1633 os.str());
1634 }
1635 else {
1636 S.Diag(getLocationOfByte(CS.getStart()),
1637 diag::warn_printf_conversion_argument_type_mismatch)
1638 << ATR.getRepresentativeType(S.Context) << Ex->getType()
1639 << getSpecifierRange(startSpecifier, specifierLen)
1640 << Ex->getSourceRange();
1641 }
1642 }
1643
Ted Kremeneke0e53132010-01-28 23:39:18 +00001644 return true;
1645}
1646
Ted Kremenek826a3452010-07-16 02:11:22 +00001647//===--- CHECK: Scanf format string checking ------------------------------===//
1648
1649namespace {
1650class CheckScanfHandler : public CheckFormatHandler {
1651public:
1652 CheckScanfHandler(Sema &s, const StringLiteral *fexpr,
1653 const Expr *origFormatExpr, unsigned firstDataArg,
1654 unsigned numDataArgs, bool isObjCLiteral,
1655 const char *beg, bool hasVAListArg,
1656 const CallExpr *theCall, unsigned formatIdx)
1657 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg,
1658 numDataArgs, isObjCLiteral, beg, hasVAListArg,
1659 theCall, formatIdx) {}
1660
1661 bool HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier &FS,
1662 const char *startSpecifier,
1663 unsigned specifierLen);
Ted Kremenekc09b6a52010-07-19 21:25:57 +00001664
1665 bool HandleInvalidScanfConversionSpecifier(
1666 const analyze_scanf::ScanfSpecifier &FS,
1667 const char *startSpecifier,
1668 unsigned specifierLen);
Ted Kremenekb7c21012010-07-16 18:28:03 +00001669
1670 void HandleIncompleteScanList(const char *start, const char *end);
Ted Kremenek826a3452010-07-16 02:11:22 +00001671};
Ted Kremenek07d161f2010-01-29 01:50:07 +00001672}
Ted Kremeneke0e53132010-01-28 23:39:18 +00001673
Ted Kremenekb7c21012010-07-16 18:28:03 +00001674void CheckScanfHandler::HandleIncompleteScanList(const char *start,
1675 const char *end) {
1676 S.Diag(getLocationOfByte(end), diag::warn_scanf_scanlist_incomplete)
1677 << getSpecifierRange(start, end - start);
1678}
1679
Ted Kremenekc09b6a52010-07-19 21:25:57 +00001680bool CheckScanfHandler::HandleInvalidScanfConversionSpecifier(
1681 const analyze_scanf::ScanfSpecifier &FS,
1682 const char *startSpecifier,
1683 unsigned specifierLen) {
1684
Ted Kremenek6ecb9502010-07-20 20:04:27 +00001685 const analyze_scanf::ScanfConversionSpecifier &CS =
Ted Kremenekc09b6a52010-07-19 21:25:57 +00001686 FS.getConversionSpecifier();
1687
1688 return HandleInvalidConversionSpecifier(FS.getArgIndex(),
1689 getLocationOfByte(CS.getStart()),
1690 startSpecifier, specifierLen,
1691 CS.getStart(), CS.getLength());
1692}
1693
Ted Kremenek826a3452010-07-16 02:11:22 +00001694bool CheckScanfHandler::HandleScanfSpecifier(
1695 const analyze_scanf::ScanfSpecifier &FS,
1696 const char *startSpecifier,
1697 unsigned specifierLen) {
1698
1699 using namespace analyze_scanf;
1700 using namespace analyze_format_string;
1701
Ted Kremenek6ecb9502010-07-20 20:04:27 +00001702 const ScanfConversionSpecifier &CS = FS.getConversionSpecifier();
Ted Kremenek826a3452010-07-16 02:11:22 +00001703
Ted Kremenekbaa40062010-07-19 22:01:06 +00001704 // Handle case where '%' and '*' don't consume an argument. These shouldn't
1705 // be used to decide if we are using positional arguments consistently.
1706 if (FS.consumesDataArgument()) {
1707 if (atFirstArg) {
1708 atFirstArg = false;
1709 usesPositionalArgs = FS.usesPositionalArg();
1710 }
1711 else if (usesPositionalArgs != FS.usesPositionalArg()) {
1712 // Cannot mix-and-match positional and non-positional arguments.
1713 S.Diag(getLocationOfByte(CS.getStart()),
1714 diag::warn_format_mix_positional_nonpositional_args)
1715 << getSpecifierRange(startSpecifier, specifierLen);
1716 return false;
1717 }
Ted Kremenek826a3452010-07-16 02:11:22 +00001718 }
1719
1720 // Check if the field with is non-zero.
1721 const OptionalAmount &Amt = FS.getFieldWidth();
1722 if (Amt.getHowSpecified() == OptionalAmount::Constant) {
1723 if (Amt.getConstantAmount() == 0) {
1724 const CharSourceRange &R = getSpecifierRange(Amt.getStart(),
1725 Amt.getConstantLength());
1726 S.Diag(getLocationOfByte(Amt.getStart()),
1727 diag::warn_scanf_nonzero_width)
1728 << R << FixItHint::CreateRemoval(R);
1729 }
1730 }
1731
1732 if (!FS.consumesDataArgument()) {
1733 // FIXME: Technically specifying a precision or field width here
1734 // makes no sense. Worth issuing a warning at some point.
1735 return true;
1736 }
1737
1738 // Consume the argument.
1739 unsigned argIndex = FS.getArgIndex();
1740 if (argIndex < NumDataArgs) {
1741 // The check to see if the argIndex is valid will come later.
1742 // We set the bit here because we may exit early from this
1743 // function if we encounter some other error.
1744 CoveredArgs.set(argIndex);
1745 }
1746
Ted Kremenek1e51c202010-07-20 20:04:47 +00001747 // Check the length modifier is valid with the given conversion specifier.
1748 const LengthModifier &LM = FS.getLengthModifier();
1749 if (!FS.hasValidLengthModifier()) {
1750 S.Diag(getLocationOfByte(LM.getStart()),
1751 diag::warn_format_nonsensical_length)
1752 << LM.toString() << CS.toString()
1753 << getSpecifierRange(startSpecifier, specifierLen)
1754 << FixItHint::CreateRemoval(getSpecifierRange(LM.getStart(),
1755 LM.getLength()));
1756 }
1757
Ted Kremenek826a3452010-07-16 02:11:22 +00001758 // The remaining checks depend on the data arguments.
1759 if (HasVAListArg)
1760 return true;
1761
Ted Kremenek666a1972010-07-26 19:45:42 +00001762 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex))
Ted Kremenek826a3452010-07-16 02:11:22 +00001763 return false;
Ted Kremenek826a3452010-07-16 02:11:22 +00001764
1765 // FIXME: Check that the argument type matches the format specifier.
1766
1767 return true;
1768}
1769
1770void Sema::CheckFormatString(const StringLiteral *FExpr,
Ted Kremenek0e5675d2010-02-10 02:16:30 +00001771 const Expr *OrigFormatExpr,
1772 const CallExpr *TheCall, bool HasVAListArg,
Ted Kremenek826a3452010-07-16 02:11:22 +00001773 unsigned format_idx, unsigned firstDataArg,
1774 bool isPrintf) {
1775
Ted Kremeneke0e53132010-01-28 23:39:18 +00001776 // CHECK: is the format string a wide literal?
1777 if (FExpr->isWide()) {
1778 Diag(FExpr->getLocStart(),
Ted Kremenek826a3452010-07-16 02:11:22 +00001779 diag::warn_format_string_is_wide_literal)
Ted Kremeneke0e53132010-01-28 23:39:18 +00001780 << OrigFormatExpr->getSourceRange();
1781 return;
1782 }
Ted Kremenek826a3452010-07-16 02:11:22 +00001783
Ted Kremeneke0e53132010-01-28 23:39:18 +00001784 // Str - The format string. NOTE: this is NOT null-terminated!
Benjamin Kramer2f4eaef2010-08-17 12:54:38 +00001785 llvm::StringRef StrRef = FExpr->getString();
1786 const char *Str = StrRef.data();
1787 unsigned StrLen = StrRef.size();
Ted Kremenek826a3452010-07-16 02:11:22 +00001788
Ted Kremeneke0e53132010-01-28 23:39:18 +00001789 // CHECK: empty format string?
Ted Kremeneke0e53132010-01-28 23:39:18 +00001790 if (StrLen == 0) {
Ted Kremenek826a3452010-07-16 02:11:22 +00001791 Diag(FExpr->getLocStart(), diag::warn_empty_format_string)
Ted Kremeneke0e53132010-01-28 23:39:18 +00001792 << OrigFormatExpr->getSourceRange();
1793 return;
1794 }
Ted Kremenek826a3452010-07-16 02:11:22 +00001795
1796 if (isPrintf) {
1797 CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
1798 TheCall->getNumArgs() - firstDataArg,
1799 isa<ObjCStringLiteral>(OrigFormatExpr), Str,
1800 HasVAListArg, TheCall, format_idx);
1801
1802 if (!analyze_format_string::ParsePrintfString(H, Str, Str + StrLen))
1803 H.DoneProcessing();
1804 }
1805 else {
1806 CheckScanfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg,
1807 TheCall->getNumArgs() - firstDataArg,
1808 isa<ObjCStringLiteral>(OrigFormatExpr), Str,
1809 HasVAListArg, TheCall, format_idx);
1810
1811 if (!analyze_format_string::ParseScanfString(H, Str, Str + StrLen))
1812 H.DoneProcessing();
1813 }
Ted Kremenekce7024e2010-01-28 01:18:22 +00001814}
1815
Ted Kremenek06de2762007-08-17 16:46:58 +00001816//===--- CHECK: Return Address of Stack Variable --------------------------===//
1817
1818static DeclRefExpr* EvalVal(Expr *E);
1819static DeclRefExpr* EvalAddr(Expr* E);
1820
1821/// CheckReturnStackAddr - Check if a return statement returns the address
1822/// of a stack variable.
1823void
1824Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType,
1825 SourceLocation ReturnLoc) {
Mike Stump1eb44332009-09-09 15:08:12 +00001826
Ted Kremenek06de2762007-08-17 16:46:58 +00001827 // Perform checking for returned stack addresses.
Steve Naroffdd972f22008-09-05 22:11:13 +00001828 if (lhsType->isPointerType() || lhsType->isBlockPointerType()) {
Ted Kremenek06de2762007-08-17 16:46:58 +00001829 if (DeclRefExpr *DR = EvalAddr(RetValExp))
Chris Lattner3c73c412008-11-19 08:23:25 +00001830 Diag(DR->getLocStart(), diag::warn_ret_stack_addr)
Chris Lattner08631c52008-11-23 21:45:46 +00001831 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange();
Mike Stump1eb44332009-09-09 15:08:12 +00001832
Steve Naroffc50a4a52008-09-16 22:25:10 +00001833 // Skip over implicit cast expressions when checking for block expressions.
Chris Lattner4ca606e2009-09-08 00:36:37 +00001834 RetValExp = RetValExp->IgnoreParenCasts();
Steve Naroffc50a4a52008-09-16 22:25:10 +00001835
Chris Lattner9e6b37a2009-10-30 04:01:58 +00001836 if (BlockExpr *C = dyn_cast<BlockExpr>(RetValExp))
Mike Stump397195b2009-04-17 00:09:41 +00001837 if (C->hasBlockDeclRefExprs())
1838 Diag(C->getLocStart(), diag::err_ret_local_block)
1839 << C->getSourceRange();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001840
Chris Lattner9e6b37a2009-10-30 04:01:58 +00001841 if (AddrLabelExpr *ALE = dyn_cast<AddrLabelExpr>(RetValExp))
1842 Diag(ALE->getLocStart(), diag::warn_ret_addr_label)
1843 << ALE->getSourceRange();
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00001844
Mike Stumpac5fc7c2009-08-04 21:02:39 +00001845 } else if (lhsType->isReferenceType()) {
1846 // Perform checking for stack values returned by reference.
Douglas Gregor49badde2008-10-27 19:41:14 +00001847 // Check for a reference to the stack
1848 if (DeclRefExpr *DR = EvalVal(RetValExp))
Chris Lattnerdcd5ef12008-11-19 05:27:50 +00001849 Diag(DR->getLocStart(), diag::warn_ret_stack_ref)
Chris Lattner08631c52008-11-23 21:45:46 +00001850 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange();
Ted Kremenek06de2762007-08-17 16:46:58 +00001851 }
1852}
1853
1854/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that
1855/// check if the expression in a return statement evaluates to an address
1856/// to a location on the stack. The recursion is used to traverse the
1857/// AST of the return expression, with recursion backtracking when we
1858/// encounter a subexpression that (1) clearly does not lead to the address
1859/// of a stack variable or (2) is something we cannot determine leads to
1860/// the address of a stack variable based on such local checking.
1861///
Ted Kremeneke8c600f2007-08-28 17:02:55 +00001862/// EvalAddr processes expressions that are pointers that are used as
1863/// references (and not L-values). EvalVal handles all other values.
Mike Stump1eb44332009-09-09 15:08:12 +00001864/// At the base case of the recursion is a check for a DeclRefExpr* in
Ted Kremenek06de2762007-08-17 16:46:58 +00001865/// the refers to a stack variable.
1866///
1867/// This implementation handles:
1868///
1869/// * pointer-to-pointer casts
1870/// * implicit conversions from array references to pointers
1871/// * taking the address of fields
1872/// * arbitrary interplay between "&" and "*" operators
1873/// * pointer arithmetic from an address of a stack variable
1874/// * taking the address of an array element where the array is on the stack
1875static DeclRefExpr* EvalAddr(Expr *E) {
Ted Kremenek06de2762007-08-17 16:46:58 +00001876 // We should only be called for evaluating pointer expressions.
David Chisnall0f436562009-08-17 16:35:33 +00001877 assert((E->getType()->isAnyPointerType() ||
Steve Naroffdd972f22008-09-05 22:11:13 +00001878 E->getType()->isBlockPointerType() ||
Ted Kremeneka526c5c2008-01-07 19:49:32 +00001879 E->getType()->isObjCQualifiedIdType()) &&
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001880 "EvalAddr only works on pointers");
Mike Stump1eb44332009-09-09 15:08:12 +00001881
Ted Kremenek06de2762007-08-17 16:46:58 +00001882 // Our "symbolic interpreter" is just a dispatch off the currently
1883 // viewed AST node. We then recursively traverse the AST by calling
1884 // EvalAddr and EvalVal appropriately.
1885 switch (E->getStmtClass()) {
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001886 case Stmt::ParenExprClass:
1887 // Ignore parentheses.
1888 return EvalAddr(cast<ParenExpr>(E)->getSubExpr());
Ted Kremenek06de2762007-08-17 16:46:58 +00001889
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001890 case Stmt::UnaryOperatorClass: {
1891 // The only unary operator that make sense to handle here
1892 // is AddrOf. All others don't make sense as pointers.
1893 UnaryOperator *U = cast<UnaryOperator>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00001894
John McCall2de56d12010-08-25 11:45:40 +00001895 if (U->getOpcode() == UO_AddrOf)
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001896 return EvalVal(U->getSubExpr());
1897 else
Ted Kremenek06de2762007-08-17 16:46:58 +00001898 return NULL;
1899 }
Mike Stump1eb44332009-09-09 15:08:12 +00001900
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001901 case Stmt::BinaryOperatorClass: {
1902 // Handle pointer arithmetic. All other binary operators are not valid
1903 // in this context.
1904 BinaryOperator *B = cast<BinaryOperator>(E);
John McCall2de56d12010-08-25 11:45:40 +00001905 BinaryOperatorKind op = B->getOpcode();
Mike Stump1eb44332009-09-09 15:08:12 +00001906
John McCall2de56d12010-08-25 11:45:40 +00001907 if (op != BO_Add && op != BO_Sub)
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001908 return NULL;
Mike Stump1eb44332009-09-09 15:08:12 +00001909
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001910 Expr *Base = B->getLHS();
1911
1912 // Determine which argument is the real pointer base. It could be
1913 // the RHS argument instead of the LHS.
1914 if (!Base->getType()->isPointerType()) Base = B->getRHS();
Mike Stump1eb44332009-09-09 15:08:12 +00001915
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001916 assert (Base->getType()->isPointerType());
1917 return EvalAddr(Base);
1918 }
Steve Naroff61f40a22008-09-10 19:17:48 +00001919
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001920 // For conditional operators we need to see if either the LHS or RHS are
1921 // valid DeclRefExpr*s. If one of them is valid, we return it.
1922 case Stmt::ConditionalOperatorClass: {
1923 ConditionalOperator *C = cast<ConditionalOperator>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00001924
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001925 // Handle the GNU extension for missing LHS.
1926 if (Expr *lhsExpr = C->getLHS())
1927 if (DeclRefExpr* LHS = EvalAddr(lhsExpr))
1928 return LHS;
1929
1930 return EvalAddr(C->getRHS());
1931 }
Mike Stump1eb44332009-09-09 15:08:12 +00001932
Ted Kremenek54b52742008-08-07 00:49:01 +00001933 // For casts, we need to handle conversions from arrays to
1934 // pointer values, and pointer-to-pointer conversions.
Douglas Gregor49badde2008-10-27 19:41:14 +00001935 case Stmt::ImplicitCastExprClass:
Douglas Gregor6eec8e82008-10-28 15:36:24 +00001936 case Stmt::CStyleCastExprClass:
Douglas Gregor49badde2008-10-27 19:41:14 +00001937 case Stmt::CXXFunctionalCastExprClass: {
Argyrios Kyrtzidis0835a3c2008-08-18 23:01:59 +00001938 Expr* SubExpr = cast<CastExpr>(E)->getSubExpr();
Ted Kremenek54b52742008-08-07 00:49:01 +00001939 QualType T = SubExpr->getType();
Mike Stump1eb44332009-09-09 15:08:12 +00001940
Steve Naroffdd972f22008-09-05 22:11:13 +00001941 if (SubExpr->getType()->isPointerType() ||
1942 SubExpr->getType()->isBlockPointerType() ||
1943 SubExpr->getType()->isObjCQualifiedIdType())
Ted Kremenek54b52742008-08-07 00:49:01 +00001944 return EvalAddr(SubExpr);
1945 else if (T->isArrayType())
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001946 return EvalVal(SubExpr);
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001947 else
Ted Kremenek54b52742008-08-07 00:49:01 +00001948 return 0;
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001949 }
Mike Stump1eb44332009-09-09 15:08:12 +00001950
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001951 // C++ casts. For dynamic casts, static casts, and const casts, we
1952 // are always converting from a pointer-to-pointer, so we just blow
Douglas Gregor49badde2008-10-27 19:41:14 +00001953 // through the cast. In the case the dynamic cast doesn't fail (and
1954 // return NULL), we take the conservative route and report cases
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001955 // where we return the address of a stack variable. For Reinterpre
Douglas Gregor49badde2008-10-27 19:41:14 +00001956 // FIXME: The comment about is wrong; we're not always converting
1957 // from pointer to pointer. I'm guessing that this code should also
Mike Stump1eb44332009-09-09 15:08:12 +00001958 // handle references to objects.
1959 case Stmt::CXXStaticCastExprClass:
1960 case Stmt::CXXDynamicCastExprClass:
Douglas Gregor49badde2008-10-27 19:41:14 +00001961 case Stmt::CXXConstCastExprClass:
1962 case Stmt::CXXReinterpretCastExprClass: {
1963 Expr *S = cast<CXXNamedCastExpr>(E)->getSubExpr();
Steve Naroffdd972f22008-09-05 22:11:13 +00001964 if (S->getType()->isPointerType() || S->getType()->isBlockPointerType())
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001965 return EvalAddr(S);
1966 else
1967 return NULL;
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001968 }
Mike Stump1eb44332009-09-09 15:08:12 +00001969
Chris Lattnerfae3f1f2007-12-28 05:31:15 +00001970 // Everything else: we simply don't reason about them.
1971 default:
1972 return NULL;
1973 }
Ted Kremenek06de2762007-08-17 16:46:58 +00001974}
Mike Stump1eb44332009-09-09 15:08:12 +00001975
Ted Kremenek06de2762007-08-17 16:46:58 +00001976
1977/// EvalVal - This function is complements EvalAddr in the mutual recursion.
1978/// See the comments for EvalAddr for more details.
1979static DeclRefExpr* EvalVal(Expr *E) {
Ted Kremenek68957a92010-08-04 20:01:07 +00001980do {
Ted Kremeneke8c600f2007-08-28 17:02:55 +00001981 // We should only be called for evaluating non-pointer expressions, or
1982 // expressions with a pointer type that are not used as references but instead
1983 // are l-values (e.g., DeclRefExpr with a pointer type).
Mike Stump1eb44332009-09-09 15:08:12 +00001984
Ted Kremenek06de2762007-08-17 16:46:58 +00001985 // Our "symbolic interpreter" is just a dispatch off the currently
1986 // viewed AST node. We then recursively traverse the AST by calling
1987 // EvalAddr and EvalVal appropriately.
1988 switch (E->getStmtClass()) {
Ted Kremenek68957a92010-08-04 20:01:07 +00001989 case Stmt::ImplicitCastExprClass: {
1990 ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E);
John McCall5baba9d2010-08-25 10:28:54 +00001991 if (IE->getValueKind() == VK_LValue) {
Ted Kremenek68957a92010-08-04 20:01:07 +00001992 E = IE->getSubExpr();
1993 continue;
1994 }
1995 return NULL;
1996 }
1997
Douglas Gregora2813ce2009-10-23 18:54:35 +00001998 case Stmt::DeclRefExprClass: {
Ted Kremenek06de2762007-08-17 16:46:58 +00001999 // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking
2000 // at code that refers to a variable's name. We check if it has local
2001 // storage within the function, and if so, return the expression.
2002 DeclRefExpr *DR = cast<DeclRefExpr>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00002003
Ted Kremenek06de2762007-08-17 16:46:58 +00002004 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl()))
Mike Stump1eb44332009-09-09 15:08:12 +00002005 if (V->hasLocalStorage() && !V->getType()->isReferenceType()) return DR;
2006
Ted Kremenek06de2762007-08-17 16:46:58 +00002007 return NULL;
2008 }
Mike Stump1eb44332009-09-09 15:08:12 +00002009
Ted Kremenek68957a92010-08-04 20:01:07 +00002010 case Stmt::ParenExprClass: {
Ted Kremenek06de2762007-08-17 16:46:58 +00002011 // Ignore parentheses.
Ted Kremenek68957a92010-08-04 20:01:07 +00002012 E = cast<ParenExpr>(E)->getSubExpr();
2013 continue;
2014 }
Mike Stump1eb44332009-09-09 15:08:12 +00002015
Ted Kremenek06de2762007-08-17 16:46:58 +00002016 case Stmt::UnaryOperatorClass: {
2017 // The only unary operator that make sense to handle here
2018 // is Deref. All others don't resolve to a "name." This includes
2019 // handling all sorts of rvalues passed to a unary operator.
2020 UnaryOperator *U = cast<UnaryOperator>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00002021
John McCall2de56d12010-08-25 11:45:40 +00002022 if (U->getOpcode() == UO_Deref)
Ted Kremenek06de2762007-08-17 16:46:58 +00002023 return EvalAddr(U->getSubExpr());
2024
2025 return NULL;
2026 }
Mike Stump1eb44332009-09-09 15:08:12 +00002027
Ted Kremenek06de2762007-08-17 16:46:58 +00002028 case Stmt::ArraySubscriptExprClass: {
2029 // Array subscripts are potential references to data on the stack. We
2030 // retrieve the DeclRefExpr* for the array variable if it indeed
2031 // has local storage.
Ted Kremenek23245122007-08-20 16:18:38 +00002032 return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase());
Ted Kremenek06de2762007-08-17 16:46:58 +00002033 }
Mike Stump1eb44332009-09-09 15:08:12 +00002034
Ted Kremenek06de2762007-08-17 16:46:58 +00002035 case Stmt::ConditionalOperatorClass: {
2036 // For conditional operators we need to see if either the LHS or RHS are
2037 // non-NULL DeclRefExpr's. If one is non-NULL, we return it.
2038 ConditionalOperator *C = cast<ConditionalOperator>(E);
2039
Anders Carlsson39073232007-11-30 19:04:31 +00002040 // Handle the GNU extension for missing LHS.
2041 if (Expr *lhsExpr = C->getLHS())
2042 if (DeclRefExpr *LHS = EvalVal(lhsExpr))
2043 return LHS;
2044
2045 return EvalVal(C->getRHS());
Ted Kremenek06de2762007-08-17 16:46:58 +00002046 }
Mike Stump1eb44332009-09-09 15:08:12 +00002047
Ted Kremenek06de2762007-08-17 16:46:58 +00002048 // Accesses to members are potential references to data on the stack.
Douglas Gregor83f6faf2009-08-31 23:41:50 +00002049 case Stmt::MemberExprClass: {
Ted Kremenek06de2762007-08-17 16:46:58 +00002050 MemberExpr *M = cast<MemberExpr>(E);
Mike Stump1eb44332009-09-09 15:08:12 +00002051
Ted Kremenek06de2762007-08-17 16:46:58 +00002052 // Check for indirect access. We only want direct field accesses.
Ted Kremeneka423e812010-09-02 01:12:13 +00002053 if (M->isArrow())
Ted Kremenek06de2762007-08-17 16:46:58 +00002054 return NULL;
Ted Kremeneka423e812010-09-02 01:12:13 +00002055
2056 // Check whether the member type is itself a reference, in which case
2057 // we're not going to refer to the member, but to what the member refers to.
2058 if (M->getMemberDecl()->getType()->isReferenceType())
2059 return NULL;
2060
2061 return EvalVal(M->getBase());
Ted Kremenek06de2762007-08-17 16:46:58 +00002062 }
Mike Stump1eb44332009-09-09 15:08:12 +00002063
Ted Kremenek06de2762007-08-17 16:46:58 +00002064 // Everything else: we simply don't reason about them.
2065 default:
2066 return NULL;
2067 }
Ted Kremenek68957a92010-08-04 20:01:07 +00002068} while (true);
Ted Kremenek06de2762007-08-17 16:46:58 +00002069}
Ted Kremenek588e5eb2007-11-25 00:58:00 +00002070
2071//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===//
2072
2073/// Check for comparisons of floating point operands using != and ==.
2074/// Issue a warning if these are no self-comparisons, as they are not likely
2075/// to do what the programmer intended.
2076void Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) {
2077 bool EmitWarning = true;
Mike Stump1eb44332009-09-09 15:08:12 +00002078
Ted Kremenek4e99a5f2008-01-17 16:57:34 +00002079 Expr* LeftExprSansParen = lex->IgnoreParens();
Ted Kremenek32e97b62008-01-17 17:55:13 +00002080 Expr* RightExprSansParen = rex->IgnoreParens();
Ted Kremenek588e5eb2007-11-25 00:58:00 +00002081
2082 // Special case: check for x == x (which is OK).
2083 // Do not emit warnings for such cases.
2084 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen))
2085 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen))
2086 if (DRL->getDecl() == DRR->getDecl())
2087 EmitWarning = false;
Mike Stump1eb44332009-09-09 15:08:12 +00002088
2089
Ted Kremenek1b500bb2007-11-29 00:59:04 +00002090 // Special case: check for comparisons against literals that can be exactly
2091 // represented by APFloat. In such cases, do not emit a warning. This
2092 // is a heuristic: often comparison against such literals are used to
2093 // detect if a value in a variable has not changed. This clearly can
2094 // lead to false negatives.
2095 if (EmitWarning) {
2096 if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) {
2097 if (FLL->isExact())
2098 EmitWarning = false;
Mike Stumpac5fc7c2009-08-04 21:02:39 +00002099 } else
Ted Kremenek1b500bb2007-11-29 00:59:04 +00002100 if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){
2101 if (FLR->isExact())
2102 EmitWarning = false;
2103 }
2104 }
Mike Stump1eb44332009-09-09 15:08:12 +00002105
Ted Kremenek588e5eb2007-11-25 00:58:00 +00002106 // Check for comparisons with builtin types.
Sebastian Redl0eb23302009-01-19 00:08:26 +00002107 if (EmitWarning)
Ted Kremenek588e5eb2007-11-25 00:58:00 +00002108 if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen))
Douglas Gregor3c385e52009-02-14 18:57:46 +00002109 if (CL->isBuiltinCall(Context))
Ted Kremenek588e5eb2007-11-25 00:58:00 +00002110 EmitWarning = false;
Mike Stump1eb44332009-09-09 15:08:12 +00002111
Sebastian Redl0eb23302009-01-19 00:08:26 +00002112 if (EmitWarning)
Ted Kremenek588e5eb2007-11-25 00:58:00 +00002113 if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen))
Douglas Gregor3c385e52009-02-14 18:57:46 +00002114 if (CR->isBuiltinCall(Context))
Ted Kremenek588e5eb2007-11-25 00:58:00 +00002115 EmitWarning = false;
Mike Stump1eb44332009-09-09 15:08:12 +00002116
Ted Kremenek588e5eb2007-11-25 00:58:00 +00002117 // Emit the diagnostic.
2118 if (EmitWarning)
Chris Lattnerfa25bbb2008-11-19 05:08:23 +00002119 Diag(loc, diag::warn_floatingpoint_eq)
2120 << lex->getSourceRange() << rex->getSourceRange();
Ted Kremenek588e5eb2007-11-25 00:58:00 +00002121}
John McCallba26e582010-01-04 23:21:16 +00002122
John McCallf2370c92010-01-06 05:24:50 +00002123//===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===//
2124//===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===//
John McCallba26e582010-01-04 23:21:16 +00002125
John McCallf2370c92010-01-06 05:24:50 +00002126namespace {
John McCallba26e582010-01-04 23:21:16 +00002127
John McCallf2370c92010-01-06 05:24:50 +00002128/// Structure recording the 'active' range of an integer-valued
2129/// expression.
2130struct IntRange {
2131 /// The number of bits active in the int.
2132 unsigned Width;
John McCallba26e582010-01-04 23:21:16 +00002133
John McCallf2370c92010-01-06 05:24:50 +00002134 /// True if the int is known not to have negative values.
2135 bool NonNegative;
John McCallba26e582010-01-04 23:21:16 +00002136
John McCallf2370c92010-01-06 05:24:50 +00002137 IntRange(unsigned Width, bool NonNegative)
2138 : Width(Width), NonNegative(NonNegative)
2139 {}
John McCallba26e582010-01-04 23:21:16 +00002140
John McCallf2370c92010-01-06 05:24:50 +00002141 // Returns the range of the bool type.
2142 static IntRange forBoolType() {
2143 return IntRange(1, true);
John McCall51313c32010-01-04 23:31:57 +00002144 }
2145
John McCallf2370c92010-01-06 05:24:50 +00002146 // Returns the range of an integral type.
2147 static IntRange forType(ASTContext &C, QualType T) {
2148 return forCanonicalType(C, T->getCanonicalTypeInternal().getTypePtr());
John McCall51313c32010-01-04 23:31:57 +00002149 }
2150
John McCallf2370c92010-01-06 05:24:50 +00002151 // Returns the range of an integeral type based on its canonical
2152 // representation.
2153 static IntRange forCanonicalType(ASTContext &C, const Type *T) {
2154 assert(T->isCanonicalUnqualified());
2155
2156 if (const VectorType *VT = dyn_cast<VectorType>(T))
2157 T = VT->getElementType().getTypePtr();
2158 if (const ComplexType *CT = dyn_cast<ComplexType>(T))
2159 T = CT->getElementType().getTypePtr();
John McCall323ed742010-05-06 08:58:33 +00002160
2161 if (const EnumType *ET = dyn_cast<EnumType>(T)) {
2162 EnumDecl *Enum = ET->getDecl();
2163 unsigned NumPositive = Enum->getNumPositiveBits();
2164 unsigned NumNegative = Enum->getNumNegativeBits();
2165
2166 return IntRange(std::max(NumPositive, NumNegative), NumNegative == 0);
2167 }
John McCallf2370c92010-01-06 05:24:50 +00002168
2169 const BuiltinType *BT = cast<BuiltinType>(T);
2170 assert(BT->isInteger());
2171
2172 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger());
2173 }
2174
2175 // Returns the supremum of two ranges: i.e. their conservative merge.
John McCallc0cd21d2010-02-23 19:22:29 +00002176 static IntRange join(IntRange L, IntRange R) {
John McCallf2370c92010-01-06 05:24:50 +00002177 return IntRange(std::max(L.Width, R.Width),
John McCall60fad452010-01-06 22:07:33 +00002178 L.NonNegative && R.NonNegative);
2179 }
2180
2181 // Returns the infinum of two ranges: i.e. their aggressive merge.
John McCallc0cd21d2010-02-23 19:22:29 +00002182 static IntRange meet(IntRange L, IntRange R) {
John McCall60fad452010-01-06 22:07:33 +00002183 return IntRange(std::min(L.Width, R.Width),
2184 L.NonNegative || R.NonNegative);
John McCallf2370c92010-01-06 05:24:50 +00002185 }
2186};
2187
2188IntRange GetValueRange(ASTContext &C, llvm::APSInt &value, unsigned MaxWidth) {
2189 if (value.isSigned() && value.isNegative())
2190 return IntRange(value.getMinSignedBits(), false);
2191
2192 if (value.getBitWidth() > MaxWidth)
2193 value.trunc(MaxWidth);
2194
2195 // isNonNegative() just checks the sign bit without considering
2196 // signedness.
2197 return IntRange(value.getActiveBits(), true);
2198}
2199
John McCall0acc3112010-01-06 22:57:21 +00002200IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty,
John McCallf2370c92010-01-06 05:24:50 +00002201 unsigned MaxWidth) {
2202 if (result.isInt())
2203 return GetValueRange(C, result.getInt(), MaxWidth);
2204
2205 if (result.isVector()) {
John McCall0acc3112010-01-06 22:57:21 +00002206 IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth);
2207 for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) {
2208 IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth);
2209 R = IntRange::join(R, El);
2210 }
John McCallf2370c92010-01-06 05:24:50 +00002211 return R;
2212 }
2213
2214 if (result.isComplexInt()) {
2215 IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth);
2216 IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth);
2217 return IntRange::join(R, I);
John McCall51313c32010-01-04 23:31:57 +00002218 }
2219
2220 // This can happen with lossless casts to intptr_t of "based" lvalues.
2221 // Assume it might use arbitrary bits.
John McCall0acc3112010-01-06 22:57:21 +00002222 // FIXME: The only reason we need to pass the type in here is to get
2223 // the sign right on this one case. It would be nice if APValue
2224 // preserved this.
John McCallf2370c92010-01-06 05:24:50 +00002225 assert(result.isLValue());
John McCall0acc3112010-01-06 22:57:21 +00002226 return IntRange(MaxWidth, Ty->isUnsignedIntegerType());
John McCall51313c32010-01-04 23:31:57 +00002227}
John McCallf2370c92010-01-06 05:24:50 +00002228
2229/// Pseudo-evaluate the given integer expression, estimating the
2230/// range of values it might take.
2231///
2232/// \param MaxWidth - the width to which the value will be truncated
2233IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) {
2234 E = E->IgnoreParens();
2235
2236 // Try a full evaluation first.
2237 Expr::EvalResult result;
2238 if (E->Evaluate(result, C))
John McCall0acc3112010-01-06 22:57:21 +00002239 return GetValueRange(C, result.Val, E->getType(), MaxWidth);
John McCallf2370c92010-01-06 05:24:50 +00002240
2241 // I think we only want to look through implicit casts here; if the
2242 // user has an explicit widening cast, we should treat the value as
2243 // being of the new, wider type.
2244 if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) {
John McCall2de56d12010-08-25 11:45:40 +00002245 if (CE->getCastKind() == CK_NoOp)
John McCallf2370c92010-01-06 05:24:50 +00002246 return GetExprRange(C, CE->getSubExpr(), MaxWidth);
2247
2248 IntRange OutputTypeRange = IntRange::forType(C, CE->getType());
2249
John McCall2de56d12010-08-25 11:45:40 +00002250 bool isIntegerCast = (CE->getCastKind() == CK_IntegralCast);
2251 if (!isIntegerCast && CE->getCastKind() == CK_Unknown)
John McCall60fad452010-01-06 22:07:33 +00002252 isIntegerCast = CE->getSubExpr()->getType()->isIntegerType();
2253
John McCallf2370c92010-01-06 05:24:50 +00002254 // Assume that non-integer casts can span the full range of the type.
John McCall60fad452010-01-06 22:07:33 +00002255 if (!isIntegerCast)
John McCallf2370c92010-01-06 05:24:50 +00002256 return OutputTypeRange;
2257
2258 IntRange SubRange
2259 = GetExprRange(C, CE->getSubExpr(),
2260 std::min(MaxWidth, OutputTypeRange.Width));
2261
2262 // Bail out if the subexpr's range is as wide as the cast type.
2263 if (SubRange.Width >= OutputTypeRange.Width)
2264 return OutputTypeRange;
2265
2266 // Otherwise, we take the smaller width, and we're non-negative if
2267 // either the output type or the subexpr is.
2268 return IntRange(SubRange.Width,
2269 SubRange.NonNegative || OutputTypeRange.NonNegative);
2270 }
2271
2272 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
2273 // If we can fold the condition, just take that operand.
2274 bool CondResult;
2275 if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C))
2276 return GetExprRange(C, CondResult ? CO->getTrueExpr()
2277 : CO->getFalseExpr(),
2278 MaxWidth);
2279
2280 // Otherwise, conservatively merge.
2281 IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth);
2282 IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth);
2283 return IntRange::join(L, R);
2284 }
2285
2286 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
2287 switch (BO->getOpcode()) {
2288
2289 // Boolean-valued operations are single-bit and positive.
John McCall2de56d12010-08-25 11:45:40 +00002290 case BO_LAnd:
2291 case BO_LOr:
2292 case BO_LT:
2293 case BO_GT:
2294 case BO_LE:
2295 case BO_GE:
2296 case BO_EQ:
2297 case BO_NE:
John McCallf2370c92010-01-06 05:24:50 +00002298 return IntRange::forBoolType();
2299
John McCallc0cd21d2010-02-23 19:22:29 +00002300 // The type of these compound assignments is the type of the LHS,
2301 // so the RHS is not necessarily an integer.
John McCall2de56d12010-08-25 11:45:40 +00002302 case BO_MulAssign:
2303 case BO_DivAssign:
2304 case BO_RemAssign:
2305 case BO_AddAssign:
2306 case BO_SubAssign:
John McCallc0cd21d2010-02-23 19:22:29 +00002307 return IntRange::forType(C, E->getType());
2308
John McCallf2370c92010-01-06 05:24:50 +00002309 // Operations with opaque sources are black-listed.
John McCall2de56d12010-08-25 11:45:40 +00002310 case BO_PtrMemD:
2311 case BO_PtrMemI:
John McCallf2370c92010-01-06 05:24:50 +00002312 return IntRange::forType(C, E->getType());
2313
John McCall60fad452010-01-06 22:07:33 +00002314 // Bitwise-and uses the *infinum* of the two source ranges.
John McCall2de56d12010-08-25 11:45:40 +00002315 case BO_And:
2316 case BO_AndAssign:
John McCall60fad452010-01-06 22:07:33 +00002317 return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth),
2318 GetExprRange(C, BO->getRHS(), MaxWidth));
2319
John McCallf2370c92010-01-06 05:24:50 +00002320 // Left shift gets black-listed based on a judgement call.
John McCall2de56d12010-08-25 11:45:40 +00002321 case BO_Shl:
John McCall3aae6092010-04-07 01:14:35 +00002322 // ...except that we want to treat '1 << (blah)' as logically
2323 // positive. It's an important idiom.
2324 if (IntegerLiteral *I
2325 = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) {
2326 if (I->getValue() == 1) {
2327 IntRange R = IntRange::forType(C, E->getType());
2328 return IntRange(R.Width, /*NonNegative*/ true);
2329 }
2330 }
2331 // fallthrough
2332
John McCall2de56d12010-08-25 11:45:40 +00002333 case BO_ShlAssign:
John McCallf2370c92010-01-06 05:24:50 +00002334 return IntRange::forType(C, E->getType());
2335
John McCall60fad452010-01-06 22:07:33 +00002336 // Right shift by a constant can narrow its left argument.
John McCall2de56d12010-08-25 11:45:40 +00002337 case BO_Shr:
2338 case BO_ShrAssign: {
John McCall60fad452010-01-06 22:07:33 +00002339 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
2340
2341 // If the shift amount is a positive constant, drop the width by
2342 // that much.
2343 llvm::APSInt shift;
2344 if (BO->getRHS()->isIntegerConstantExpr(shift, C) &&
2345 shift.isNonNegative()) {
2346 unsigned zext = shift.getZExtValue();
2347 if (zext >= L.Width)
2348 L.Width = (L.NonNegative ? 0 : 1);
2349 else
2350 L.Width -= zext;
2351 }
2352
2353 return L;
2354 }
2355
2356 // Comma acts as its right operand.
John McCall2de56d12010-08-25 11:45:40 +00002357 case BO_Comma:
John McCallf2370c92010-01-06 05:24:50 +00002358 return GetExprRange(C, BO->getRHS(), MaxWidth);
2359
John McCall60fad452010-01-06 22:07:33 +00002360 // Black-list pointer subtractions.
John McCall2de56d12010-08-25 11:45:40 +00002361 case BO_Sub:
John McCallf2370c92010-01-06 05:24:50 +00002362 if (BO->getLHS()->getType()->isPointerType())
2363 return IntRange::forType(C, E->getType());
2364 // fallthrough
Ted Kremenek4e4b30e2010-02-16 01:46:59 +00002365
John McCallf2370c92010-01-06 05:24:50 +00002366 default:
2367 break;
2368 }
2369
2370 // Treat every other operator as if it were closed on the
2371 // narrowest type that encompasses both operands.
2372 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth);
2373 IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth);
2374 return IntRange::join(L, R);
2375 }
2376
2377 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
2378 switch (UO->getOpcode()) {
2379 // Boolean-valued operations are white-listed.
John McCall2de56d12010-08-25 11:45:40 +00002380 case UO_LNot:
John McCallf2370c92010-01-06 05:24:50 +00002381 return IntRange::forBoolType();
2382
2383 // Operations with opaque sources are black-listed.
John McCall2de56d12010-08-25 11:45:40 +00002384 case UO_Deref:
2385 case UO_AddrOf: // should be impossible
John McCallf2370c92010-01-06 05:24:50 +00002386 return IntRange::forType(C, E->getType());
2387
2388 default:
2389 return GetExprRange(C, UO->getSubExpr(), MaxWidth);
2390 }
2391 }
Douglas Gregor8ecdb652010-04-28 22:16:22 +00002392
2393 if (dyn_cast<OffsetOfExpr>(E)) {
2394 IntRange::forType(C, E->getType());
2395 }
John McCallf2370c92010-01-06 05:24:50 +00002396
2397 FieldDecl *BitField = E->getBitField();
2398 if (BitField) {
2399 llvm::APSInt BitWidthAP = BitField->getBitWidth()->EvaluateAsInt(C);
2400 unsigned BitWidth = BitWidthAP.getZExtValue();
2401
2402 return IntRange(BitWidth, BitField->getType()->isUnsignedIntegerType());
2403 }
2404
2405 return IntRange::forType(C, E->getType());
2406}
John McCall51313c32010-01-04 23:31:57 +00002407
John McCall323ed742010-05-06 08:58:33 +00002408IntRange GetExprRange(ASTContext &C, Expr *E) {
2409 return GetExprRange(C, E, C.getIntWidth(E->getType()));
2410}
2411
John McCall51313c32010-01-04 23:31:57 +00002412/// Checks whether the given value, which currently has the given
2413/// source semantics, has the same value when coerced through the
2414/// target semantics.
John McCallf2370c92010-01-06 05:24:50 +00002415bool IsSameFloatAfterCast(const llvm::APFloat &value,
2416 const llvm::fltSemantics &Src,
2417 const llvm::fltSemantics &Tgt) {
John McCall51313c32010-01-04 23:31:57 +00002418 llvm::APFloat truncated = value;
2419
2420 bool ignored;
2421 truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored);
2422 truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored);
2423
2424 return truncated.bitwiseIsEqual(value);
2425}
2426
2427/// Checks whether the given value, which currently has the given
2428/// source semantics, has the same value when coerced through the
2429/// target semantics.
2430///
2431/// The value might be a vector of floats (or a complex number).
John McCallf2370c92010-01-06 05:24:50 +00002432bool IsSameFloatAfterCast(const APValue &value,
2433 const llvm::fltSemantics &Src,
2434 const llvm::fltSemantics &Tgt) {
John McCall51313c32010-01-04 23:31:57 +00002435 if (value.isFloat())
2436 return IsSameFloatAfterCast(value.getFloat(), Src, Tgt);
2437
2438 if (value.isVector()) {
2439 for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i)
2440 if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt))
2441 return false;
2442 return true;
2443 }
2444
2445 assert(value.isComplexFloat());
2446 return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) &&
2447 IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt));
2448}
2449
John McCall323ed742010-05-06 08:58:33 +00002450void AnalyzeImplicitConversions(Sema &S, Expr *E);
2451
2452bool IsZero(Sema &S, Expr *E) {
2453 llvm::APSInt Value;
2454 return E->isIntegerConstantExpr(Value, S.Context) && Value == 0;
2455}
2456
2457void CheckTrivialUnsignedComparison(Sema &S, BinaryOperator *E) {
John McCall2de56d12010-08-25 11:45:40 +00002458 BinaryOperatorKind op = E->getOpcode();
2459 if (op == BO_LT && IsZero(S, E->getRHS())) {
John McCall323ed742010-05-06 08:58:33 +00002460 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
2461 << "< 0" << "false"
2462 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
John McCall2de56d12010-08-25 11:45:40 +00002463 } else if (op == BO_GE && IsZero(S, E->getRHS())) {
John McCall323ed742010-05-06 08:58:33 +00002464 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison)
2465 << ">= 0" << "true"
2466 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
John McCall2de56d12010-08-25 11:45:40 +00002467 } else if (op == BO_GT && IsZero(S, E->getLHS())) {
John McCall323ed742010-05-06 08:58:33 +00002468 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
2469 << "0 >" << "false"
2470 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
John McCall2de56d12010-08-25 11:45:40 +00002471 } else if (op == BO_LE && IsZero(S, E->getLHS())) {
John McCall323ed742010-05-06 08:58:33 +00002472 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison)
2473 << "0 <=" << "true"
2474 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange();
2475 }
2476}
2477
2478/// Analyze the operands of the given comparison. Implements the
2479/// fallback case from AnalyzeComparison.
2480void AnalyzeImpConvsInComparison(Sema &S, BinaryOperator *E) {
2481 AnalyzeImplicitConversions(S, E->getLHS());
2482 AnalyzeImplicitConversions(S, E->getRHS());
2483}
John McCall51313c32010-01-04 23:31:57 +00002484
John McCallba26e582010-01-04 23:21:16 +00002485/// \brief Implements -Wsign-compare.
2486///
2487/// \param lex the left-hand expression
2488/// \param rex the right-hand expression
2489/// \param OpLoc the location of the joining operator
John McCalld1b47bf2010-03-11 19:43:18 +00002490/// \param BinOpc binary opcode or 0
John McCall323ed742010-05-06 08:58:33 +00002491void AnalyzeComparison(Sema &S, BinaryOperator *E) {
2492 // The type the comparison is being performed in.
2493 QualType T = E->getLHS()->getType();
2494 assert(S.Context.hasSameUnqualifiedType(T, E->getRHS()->getType())
2495 && "comparison with mismatched types");
John McCallba26e582010-01-04 23:21:16 +00002496
John McCall323ed742010-05-06 08:58:33 +00002497 // We don't do anything special if this isn't an unsigned integral
2498 // comparison: we're only interested in integral comparisons, and
2499 // signed comparisons only happen in cases we don't care to warn about.
Douglas Gregorf6094622010-07-23 15:58:24 +00002500 if (!T->hasUnsignedIntegerRepresentation())
John McCall323ed742010-05-06 08:58:33 +00002501 return AnalyzeImpConvsInComparison(S, E);
John McCallf2370c92010-01-06 05:24:50 +00002502
John McCall323ed742010-05-06 08:58:33 +00002503 Expr *lex = E->getLHS()->IgnoreParenImpCasts();
2504 Expr *rex = E->getRHS()->IgnoreParenImpCasts();
John McCallba26e582010-01-04 23:21:16 +00002505
John McCall323ed742010-05-06 08:58:33 +00002506 // Check to see if one of the (unmodified) operands is of different
2507 // signedness.
2508 Expr *signedOperand, *unsignedOperand;
Douglas Gregorf6094622010-07-23 15:58:24 +00002509 if (lex->getType()->hasSignedIntegerRepresentation()) {
2510 assert(!rex->getType()->hasSignedIntegerRepresentation() &&
John McCall323ed742010-05-06 08:58:33 +00002511 "unsigned comparison between two signed integer expressions?");
2512 signedOperand = lex;
2513 unsignedOperand = rex;
Douglas Gregorf6094622010-07-23 15:58:24 +00002514 } else if (rex->getType()->hasSignedIntegerRepresentation()) {
John McCall323ed742010-05-06 08:58:33 +00002515 signedOperand = rex;
2516 unsignedOperand = lex;
John McCallba26e582010-01-04 23:21:16 +00002517 } else {
John McCall323ed742010-05-06 08:58:33 +00002518 CheckTrivialUnsignedComparison(S, E);
2519 return AnalyzeImpConvsInComparison(S, E);
John McCallba26e582010-01-04 23:21:16 +00002520 }
2521
John McCall323ed742010-05-06 08:58:33 +00002522 // Otherwise, calculate the effective range of the signed operand.
2523 IntRange signedRange = GetExprRange(S.Context, signedOperand);
John McCallf2370c92010-01-06 05:24:50 +00002524
John McCall323ed742010-05-06 08:58:33 +00002525 // Go ahead and analyze implicit conversions in the operands. Note
2526 // that we skip the implicit conversions on both sides.
2527 AnalyzeImplicitConversions(S, lex);
2528 AnalyzeImplicitConversions(S, rex);
John McCallba26e582010-01-04 23:21:16 +00002529
John McCall323ed742010-05-06 08:58:33 +00002530 // If the signed range is non-negative, -Wsign-compare won't fire,
2531 // but we should still check for comparisons which are always true
2532 // or false.
2533 if (signedRange.NonNegative)
2534 return CheckTrivialUnsignedComparison(S, E);
John McCallba26e582010-01-04 23:21:16 +00002535
2536 // For (in)equality comparisons, if the unsigned operand is a
2537 // constant which cannot collide with a overflowed signed operand,
2538 // then reinterpreting the signed operand as unsigned will not
2539 // change the result of the comparison.
John McCall323ed742010-05-06 08:58:33 +00002540 if (E->isEqualityOp()) {
2541 unsigned comparisonWidth = S.Context.getIntWidth(T);
2542 IntRange unsignedRange = GetExprRange(S.Context, unsignedOperand);
John McCallba26e582010-01-04 23:21:16 +00002543
John McCall323ed742010-05-06 08:58:33 +00002544 // We should never be unable to prove that the unsigned operand is
2545 // non-negative.
2546 assert(unsignedRange.NonNegative && "unsigned range includes negative?");
2547
2548 if (unsignedRange.Width < comparisonWidth)
2549 return;
2550 }
2551
2552 S.Diag(E->getOperatorLoc(), diag::warn_mixed_sign_comparison)
2553 << lex->getType() << rex->getType()
2554 << lex->getSourceRange() << rex->getSourceRange();
John McCallba26e582010-01-04 23:21:16 +00002555}
2556
John McCall51313c32010-01-04 23:31:57 +00002557/// Diagnose an implicit cast; purely a helper for CheckImplicitConversion.
John McCall323ed742010-05-06 08:58:33 +00002558void DiagnoseImpCast(Sema &S, Expr *E, QualType T, unsigned diag) {
John McCall51313c32010-01-04 23:31:57 +00002559 S.Diag(E->getExprLoc(), diag) << E->getType() << T << E->getSourceRange();
2560}
2561
John McCall323ed742010-05-06 08:58:33 +00002562void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
2563 bool *ICContext = 0) {
2564 if (E->isTypeDependent() || E->isValueDependent()) return;
John McCall51313c32010-01-04 23:31:57 +00002565
John McCall323ed742010-05-06 08:58:33 +00002566 const Type *Source = S.Context.getCanonicalType(E->getType()).getTypePtr();
2567 const Type *Target = S.Context.getCanonicalType(T).getTypePtr();
2568 if (Source == Target) return;
2569 if (Target->isDependentType()) return;
John McCall51313c32010-01-04 23:31:57 +00002570
2571 // Never diagnose implicit casts to bool.
2572 if (Target->isSpecificBuiltinType(BuiltinType::Bool))
2573 return;
2574
2575 // Strip vector types.
2576 if (isa<VectorType>(Source)) {
2577 if (!isa<VectorType>(Target))
John McCall323ed742010-05-06 08:58:33 +00002578 return DiagnoseImpCast(S, E, T, diag::warn_impcast_vector_scalar);
John McCall51313c32010-01-04 23:31:57 +00002579
2580 Source = cast<VectorType>(Source)->getElementType().getTypePtr();
2581 Target = cast<VectorType>(Target)->getElementType().getTypePtr();
2582 }
2583
2584 // Strip complex types.
2585 if (isa<ComplexType>(Source)) {
2586 if (!isa<ComplexType>(Target))
John McCall323ed742010-05-06 08:58:33 +00002587 return DiagnoseImpCast(S, E, T, diag::warn_impcast_complex_scalar);
John McCall51313c32010-01-04 23:31:57 +00002588
2589 Source = cast<ComplexType>(Source)->getElementType().getTypePtr();
2590 Target = cast<ComplexType>(Target)->getElementType().getTypePtr();
2591 }
2592
2593 const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source);
2594 const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target);
2595
2596 // If the source is floating point...
2597 if (SourceBT && SourceBT->isFloatingPoint()) {
2598 // ...and the target is floating point...
2599 if (TargetBT && TargetBT->isFloatingPoint()) {
2600 // ...then warn if we're dropping FP rank.
2601
2602 // Builtin FP kinds are ordered by increasing FP rank.
2603 if (SourceBT->getKind() > TargetBT->getKind()) {
2604 // Don't warn about float constants that are precisely
2605 // representable in the target type.
2606 Expr::EvalResult result;
John McCall323ed742010-05-06 08:58:33 +00002607 if (E->Evaluate(result, S.Context)) {
John McCall51313c32010-01-04 23:31:57 +00002608 // Value might be a float, a float vector, or a float complex.
2609 if (IsSameFloatAfterCast(result.Val,
John McCall323ed742010-05-06 08:58:33 +00002610 S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)),
2611 S.Context.getFloatTypeSemantics(QualType(SourceBT, 0))))
John McCall51313c32010-01-04 23:31:57 +00002612 return;
2613 }
2614
John McCall323ed742010-05-06 08:58:33 +00002615 DiagnoseImpCast(S, E, T, diag::warn_impcast_float_precision);
John McCall51313c32010-01-04 23:31:57 +00002616 }
2617 return;
2618 }
2619
2620 // If the target is integral, always warn.
2621 if ((TargetBT && TargetBT->isInteger()))
2622 // TODO: don't warn for integer values?
John McCall323ed742010-05-06 08:58:33 +00002623 DiagnoseImpCast(S, E, T, diag::warn_impcast_float_integer);
John McCall51313c32010-01-04 23:31:57 +00002624
2625 return;
2626 }
2627
John McCallf2370c92010-01-06 05:24:50 +00002628 if (!Source->isIntegerType() || !Target->isIntegerType())
John McCall51313c32010-01-04 23:31:57 +00002629 return;
2630
John McCall323ed742010-05-06 08:58:33 +00002631 IntRange SourceRange = GetExprRange(S.Context, E);
2632 IntRange TargetRange = IntRange::forCanonicalType(S.Context, Target);
John McCallf2370c92010-01-06 05:24:50 +00002633
2634 if (SourceRange.Width > TargetRange.Width) {
John McCall51313c32010-01-04 23:31:57 +00002635 // People want to build with -Wshorten-64-to-32 and not -Wconversion
2636 // and by god we'll let them.
John McCallf2370c92010-01-06 05:24:50 +00002637 if (SourceRange.Width == 64 && TargetRange.Width == 32)
John McCall323ed742010-05-06 08:58:33 +00002638 return DiagnoseImpCast(S, E, T, diag::warn_impcast_integer_64_32);
2639 return DiagnoseImpCast(S, E, T, diag::warn_impcast_integer_precision);
2640 }
2641
2642 if ((TargetRange.NonNegative && !SourceRange.NonNegative) ||
2643 (!TargetRange.NonNegative && SourceRange.NonNegative &&
2644 SourceRange.Width == TargetRange.Width)) {
2645 unsigned DiagID = diag::warn_impcast_integer_sign;
2646
2647 // Traditionally, gcc has warned about this under -Wsign-compare.
2648 // We also want to warn about it in -Wconversion.
2649 // So if -Wconversion is off, use a completely identical diagnostic
2650 // in the sign-compare group.
2651 // The conditional-checking code will
2652 if (ICContext) {
2653 DiagID = diag::warn_impcast_integer_sign_conditional;
2654 *ICContext = true;
2655 }
2656
2657 return DiagnoseImpCast(S, E, T, DiagID);
John McCall51313c32010-01-04 23:31:57 +00002658 }
2659
2660 return;
2661}
2662
John McCall323ed742010-05-06 08:58:33 +00002663void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T);
2664
2665void CheckConditionalOperand(Sema &S, Expr *E, QualType T,
2666 bool &ICContext) {
2667 E = E->IgnoreParenImpCasts();
2668
2669 if (isa<ConditionalOperator>(E))
2670 return CheckConditionalOperator(S, cast<ConditionalOperator>(E), T);
2671
2672 AnalyzeImplicitConversions(S, E);
2673 if (E->getType() != T)
2674 return CheckImplicitConversion(S, E, T, &ICContext);
2675 return;
2676}
2677
2678void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T) {
2679 AnalyzeImplicitConversions(S, E->getCond());
2680
2681 bool Suspicious = false;
2682 CheckConditionalOperand(S, E->getTrueExpr(), T, Suspicious);
2683 CheckConditionalOperand(S, E->getFalseExpr(), T, Suspicious);
2684
2685 // If -Wconversion would have warned about either of the candidates
2686 // for a signedness conversion to the context type...
2687 if (!Suspicious) return;
2688
2689 // ...but it's currently ignored...
2690 if (S.Diags.getDiagnosticLevel(diag::warn_impcast_integer_sign_conditional))
2691 return;
2692
2693 // ...and -Wsign-compare isn't...
2694 if (!S.Diags.getDiagnosticLevel(diag::warn_mixed_sign_conditional))
2695 return;
2696
2697 // ...then check whether it would have warned about either of the
2698 // candidates for a signedness conversion to the condition type.
2699 if (E->getType() != T) {
2700 Suspicious = false;
2701 CheckImplicitConversion(S, E->getTrueExpr()->IgnoreParenImpCasts(),
2702 E->getType(), &Suspicious);
2703 if (!Suspicious)
2704 CheckImplicitConversion(S, E->getFalseExpr()->IgnoreParenImpCasts(),
2705 E->getType(), &Suspicious);
2706 if (!Suspicious)
2707 return;
2708 }
2709
2710 // If so, emit a diagnostic under -Wsign-compare.
2711 Expr *lex = E->getTrueExpr()->IgnoreParenImpCasts();
2712 Expr *rex = E->getFalseExpr()->IgnoreParenImpCasts();
2713 S.Diag(E->getQuestionLoc(), diag::warn_mixed_sign_conditional)
2714 << lex->getType() << rex->getType()
2715 << lex->getSourceRange() << rex->getSourceRange();
2716}
2717
2718/// AnalyzeImplicitConversions - Find and report any interesting
2719/// implicit conversions in the given expression. There are a couple
2720/// of competing diagnostics here, -Wconversion and -Wsign-compare.
2721void AnalyzeImplicitConversions(Sema &S, Expr *OrigE) {
2722 QualType T = OrigE->getType();
2723 Expr *E = OrigE->IgnoreParenImpCasts();
2724
2725 // For conditional operators, we analyze the arguments as if they
2726 // were being fed directly into the output.
2727 if (isa<ConditionalOperator>(E)) {
2728 ConditionalOperator *CO = cast<ConditionalOperator>(E);
2729 CheckConditionalOperator(S, CO, T);
2730 return;
2731 }
2732
2733 // Go ahead and check any implicit conversions we might have skipped.
2734 // The non-canonical typecheck is just an optimization;
2735 // CheckImplicitConversion will filter out dead implicit conversions.
2736 if (E->getType() != T)
2737 CheckImplicitConversion(S, E, T);
2738
2739 // Now continue drilling into this expression.
2740
2741 // Skip past explicit casts.
2742 if (isa<ExplicitCastExpr>(E)) {
2743 E = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreParenImpCasts();
2744 return AnalyzeImplicitConversions(S, E);
2745 }
2746
2747 // Do a somewhat different check with comparison operators.
2748 if (isa<BinaryOperator>(E) && cast<BinaryOperator>(E)->isComparisonOp())
2749 return AnalyzeComparison(S, cast<BinaryOperator>(E));
2750
2751 // These break the otherwise-useful invariant below. Fortunately,
2752 // we don't really need to recurse into them, because any internal
2753 // expressions should have been analyzed already when they were
2754 // built into statements.
2755 if (isa<StmtExpr>(E)) return;
2756
2757 // Don't descend into unevaluated contexts.
2758 if (isa<SizeOfAlignOfExpr>(E)) return;
2759
2760 // Now just recurse over the expression's children.
2761 for (Stmt::child_iterator I = E->child_begin(), IE = E->child_end();
2762 I != IE; ++I)
2763 AnalyzeImplicitConversions(S, cast<Expr>(*I));
2764}
2765
2766} // end anonymous namespace
2767
2768/// Diagnoses "dangerous" implicit conversions within the given
2769/// expression (which is a full expression). Implements -Wconversion
2770/// and -Wsign-compare.
2771void Sema::CheckImplicitConversions(Expr *E) {
2772 // Don't diagnose in unevaluated contexts.
2773 if (ExprEvalContexts.back().Context == Sema::Unevaluated)
2774 return;
2775
2776 // Don't diagnose for value- or type-dependent expressions.
2777 if (E->isTypeDependent() || E->isValueDependent())
2778 return;
2779
2780 AnalyzeImplicitConversions(*this, E);
2781}
2782
Mike Stumpf8c49212010-01-21 03:59:47 +00002783/// CheckParmsForFunctionDef - Check that the parameters of the given
2784/// function are appropriate for the definition of a function. This
2785/// takes care of any checks that cannot be performed on the
2786/// declaration itself, e.g., that the types of each of the function
2787/// parameters are complete.
2788bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) {
2789 bool HasInvalidParm = false;
2790 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
2791 ParmVarDecl *Param = FD->getParamDecl(p);
2792
2793 // C99 6.7.5.3p4: the parameters in a parameter type list in a
2794 // function declarator that is part of a function definition of
2795 // that function shall not have incomplete type.
2796 //
2797 // This is also C++ [dcl.fct]p6.
2798 if (!Param->isInvalidDecl() &&
2799 RequireCompleteType(Param->getLocation(), Param->getType(),
2800 diag::err_typecheck_decl_incomplete_type)) {
2801 Param->setInvalidDecl();
2802 HasInvalidParm = true;
2803 }
2804
2805 // C99 6.9.1p5: If the declarator includes a parameter type list, the
2806 // declaration of each parameter shall include an identifier.
2807 if (Param->getIdentifier() == 0 &&
2808 !Param->isImplicit() &&
2809 !getLangOptions().CPlusPlus)
2810 Diag(Param->getLocation(), diag::err_parameter_name_omitted);
Sam Weinigd17e3402010-02-01 05:02:49 +00002811
2812 // C99 6.7.5.3p12:
2813 // If the function declarator is not part of a definition of that
2814 // function, parameters may have incomplete type and may use the [*]
2815 // notation in their sequences of declarator specifiers to specify
2816 // variable length array types.
2817 QualType PType = Param->getOriginalType();
2818 if (const ArrayType *AT = Context.getAsArrayType(PType)) {
2819 if (AT->getSizeModifier() == ArrayType::Star) {
2820 // FIXME: This diagnosic should point the the '[*]' if source-location
2821 // information is added for it.
2822 Diag(Param->getLocation(), diag::err_array_star_in_function_definition);
2823 }
2824 }
Mike Stumpf8c49212010-01-21 03:59:47 +00002825 }
2826
2827 return HasInvalidParm;
2828}
John McCallb7f4ffe2010-08-12 21:44:57 +00002829
2830/// CheckCastAlign - Implements -Wcast-align, which warns when a
2831/// pointer cast increases the alignment requirements.
2832void Sema::CheckCastAlign(Expr *Op, QualType T, SourceRange TRange) {
2833 // This is actually a lot of work to potentially be doing on every
2834 // cast; don't do it if we're ignoring -Wcast_align (as is the default).
2835 if (getDiagnostics().getDiagnosticLevel(diag::warn_cast_align)
2836 == Diagnostic::Ignored)
2837 return;
2838
2839 // Ignore dependent types.
2840 if (T->isDependentType() || Op->getType()->isDependentType())
2841 return;
2842
2843 // Require that the destination be a pointer type.
2844 const PointerType *DestPtr = T->getAs<PointerType>();
2845 if (!DestPtr) return;
2846
2847 // If the destination has alignment 1, we're done.
2848 QualType DestPointee = DestPtr->getPointeeType();
2849 if (DestPointee->isIncompleteType()) return;
2850 CharUnits DestAlign = Context.getTypeAlignInChars(DestPointee);
2851 if (DestAlign.isOne()) return;
2852
2853 // Require that the source be a pointer type.
2854 const PointerType *SrcPtr = Op->getType()->getAs<PointerType>();
2855 if (!SrcPtr) return;
2856 QualType SrcPointee = SrcPtr->getPointeeType();
2857
2858 // Whitelist casts from cv void*. We already implicitly
2859 // whitelisted casts to cv void*, since they have alignment 1.
2860 // Also whitelist casts involving incomplete types, which implicitly
2861 // includes 'void'.
2862 if (SrcPointee->isIncompleteType()) return;
2863
2864 CharUnits SrcAlign = Context.getTypeAlignInChars(SrcPointee);
2865 if (SrcAlign >= DestAlign) return;
2866
2867 Diag(TRange.getBegin(), diag::warn_cast_align)
2868 << Op->getType() << T
2869 << static_cast<unsigned>(SrcAlign.getQuantity())
2870 << static_cast<unsigned>(DestAlign.getQuantity())
2871 << TRange << Op->getSourceRange();
2872}
2873