SemaChecking.cpp revision 6ecb950c65329f8d6ce9ad0514632df35a5ab61f
1579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson//===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===// 2579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// 3579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// The LLVM Compiler Infrastructure 4579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// 5579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// This file is distributed under the University of Illinois Open Source 6579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// License. See LICENSE.TXT for details. 7579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// 8579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson//===----------------------------------------------------------------------===// 9579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// 10579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// This file implements extra semantic analysis beyond what is enforced 11579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// by the C type system. 12579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// 13579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson//===----------------------------------------------------------------------===// 14579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 15579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "Sema.h" 16579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/Analysis/Analyses/FormatString.h" 17579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/AST/ASTContext.h" 18579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/AST/CharUnits.h" 19579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/AST/DeclObjC.h" 20579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/AST/ExprCXX.h" 21579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/AST/ExprObjC.h" 22579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/AST/DeclObjC.h" 23579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/AST/StmtCXX.h" 24579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/AST/StmtObjC.h" 25579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/Lex/LiteralSupport.h" 26579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/Lex/Preprocessor.h" 27579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "llvm/ADT/BitVector.h" 28579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "llvm/ADT/STLExtras.h" 29579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "llvm/ADT/StringExtras.h" 30579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "llvm/Support/raw_ostream.h" 31579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/Basic/TargetBuiltins.h" 32579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/Basic/TargetInfo.h" 33579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include <limits> 34579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonusing namespace clang; 35579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 36579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// getLocationOfStringLiteralByte - Return a source location that points to the 37579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// specified byte of the specified string literal. 38579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// 39579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// Strings are amazingly complex. They can be formed from multiple tokens and 40579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// can have escape sequences in them in addition to the usual trigraph and 41579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// escaped newline business. This routine handles this complexity. 42579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// 43579d7739c53a2707ad711a2d2cae46d7d782f06Jesse WilsonSourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL, 44579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned ByteNo) const { 45579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson assert(!SL->isWide() && "This doesn't work for wide strings yet"); 46579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 47579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Loop over all of the tokens in this string until we find the one that 48579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // contains the byte we're looking for. 49579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned TokNo = 0; 50579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson while (1) { 51579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson assert(TokNo < SL->getNumConcatenated() && "Invalid byte number!"); 52579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson SourceLocation StrTokLoc = SL->getStrTokenLoc(TokNo); 53579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 54579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Get the spelling of the string so that we can get the data that makes up 55579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // the string literal, not the identifier for the macro it is potentially 56579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // expanded through. 57579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson SourceLocation StrTokSpellingLoc = SourceMgr.getSpellingLoc(StrTokLoc); 58579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 59579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Re-lex the token to get its length and original spelling. 60579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson std::pair<FileID, unsigned> LocInfo = 61579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson SourceMgr.getDecomposedLoc(StrTokSpellingLoc); 62579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson bool Invalid = false; 63579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson llvm::StringRef Buffer = SourceMgr.getBufferData(LocInfo.first, &Invalid); 64579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (Invalid) 65579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return StrTokSpellingLoc; 66579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 67579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson const char *StrData = Buffer.data()+LocInfo.second; 68579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 69579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Create a langops struct and enable trigraphs. This is sufficient for 70579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // relexing tokens. 71579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson LangOptions LangOpts; 72579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson LangOpts.Trigraphs = true; 73579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 74579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Create a lexer starting at the beginning of this token. 75579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Lexer TheLexer(StrTokSpellingLoc, LangOpts, Buffer.begin(), StrData, 76579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Buffer.end()); 77579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Token TheTok; 78579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson TheLexer.LexFromRawLexer(TheTok); 79579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 80579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Use the StringLiteralParser to compute the length of the string in bytes. 81579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson StringLiteralParser SLP(&TheTok, 1, PP, /*Complain=*/false); 82579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned TokNumBytes = SLP.GetStringLength(); 83579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 84579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // If the byte is in this token, return the location of the byte. 85579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (ByteNo < TokNumBytes || 86579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson (ByteNo == TokNumBytes && TokNo == SL->getNumConcatenated())) { 87579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned Offset = 88579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson StringLiteralParser::getOffsetOfStringByte(TheTok, ByteNo, PP, 89579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /*Complain=*/false); 90579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 91579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Now that we know the offset of the token in the spelling, use the 92579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // preprocessor to get the offset in the original source. 93579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return PP.AdvanceToTokenCharacter(StrTokLoc, Offset); 94579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 95579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 96579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Move to the next string token. 97579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson ++TokNo; 98579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson ByteNo -= TokNumBytes; 99579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 100579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson} 101579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 102579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// CheckablePrintfAttr - does a function call have a "printf" attribute 103579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// and arguments that merit checking? 104579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonbool Sema::CheckablePrintfAttr(const FormatAttr *Format, CallExpr *TheCall) { 105579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (Format->getType() == "printf") return true; 106579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (Format->getType() == "printf0") { 107579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // printf0 allows null "format" string; if so don't check format/args 108579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned format_idx = Format->getFormatIdx() - 1; 109579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Does the index refer to the implicit object argument? 110579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (isa<CXXMemberCallExpr>(TheCall)) { 111579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (format_idx == 0) 112579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 113579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson --format_idx; 114579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 115579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (format_idx < TheCall->getNumArgs()) { 116579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Expr *Format = TheCall->getArg(format_idx)->IgnoreParenCasts(); 117579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (!Format->isNullPointerConstant(Context, 118579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Expr::NPC_ValueDependentIsNull)) 119579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return true; 120579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 121579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 122579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 123579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson} 124579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 125579d7739c53a2707ad711a2d2cae46d7d782f06Jesse WilsonAction::OwningExprResult 126579d7739c53a2707ad711a2d2cae46d7d782f06Jesse WilsonSema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) { 127579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson OwningExprResult TheCallResult(Owned(TheCall)); 128579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 129579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson switch (BuiltinID) { 130579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin___CFStringMakeConstantString: 131579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson assert(TheCall->getNumArgs() == 1 && 132579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson "Wrong # arguments to builtin CFStringMakeConstantString"); 133579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (CheckObjCString(TheCall->getArg(0))) 134579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 135579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 136579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_stdarg_start: 137579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_va_start: 138579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinVAStart(TheCall)) 139579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 140579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 141579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_isgreater: 142579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_isgreaterequal: 143579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_isless: 144579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_islessequal: 145579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_islessgreater: 146579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_isunordered: 147579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinUnorderedCompare(TheCall)) 148579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 149579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 150579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_fpclassify: 151579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinFPClassification(TheCall, 6)) 152579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 153579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 154579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_isfinite: 155579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_isinf: 156579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_isinf_sign: 157579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_isnan: 158579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_isnormal: 159579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinFPClassification(TheCall, 1)) 160579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 161579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 162579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_return_address: 163579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_frame_address: { 164579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson llvm::APSInt Result; 165579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinConstantArg(TheCall, 0, Result)) 166579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 167579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 168579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 169579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_eh_return_data_regno: { 170579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson llvm::APSInt Result; 171579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinConstantArg(TheCall, 0, Result)) 172579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 173579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 174579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 175579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_shufflevector: 176579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return SemaBuiltinShuffleVector(TheCall); 177579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // TheCall will be freed by the smart pointer here, but that's fine, since 178579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // SemaBuiltinShuffleVector guts it, but then doesn't release it. 179579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_prefetch: 180579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinPrefetch(TheCall)) 181579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 182579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 183579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_object_size: 184579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinObjectSize(TheCall)) 185579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 186579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 187579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__builtin_longjmp: 188579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinLongjmp(TheCall)) 189579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 190579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 191579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_fetch_and_add: 192579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_fetch_and_sub: 193579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_fetch_and_or: 194579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_fetch_and_and: 195579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_fetch_and_xor: 196579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_add_and_fetch: 197579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_sub_and_fetch: 198579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_and_and_fetch: 199579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_or_and_fetch: 200579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_xor_and_fetch: 201579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_val_compare_and_swap: 202579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_bool_compare_and_swap: 203579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_lock_test_and_set: 204579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case Builtin::BI__sync_lock_release: 205579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return SemaBuiltinAtomicOverloaded(move(TheCallResult)); 206579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 207579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 208579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Since the target specific builtins for each arch overlap, only check those 209579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // of the arch we are compiling for. 210579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (BuiltinID >= Builtin::FirstTSBuiltin) { 211579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson switch (Context.Target.getTriple().getArch()) { 212579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case llvm::Triple::arm: 213579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case llvm::Triple::thumb: 214579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall)) 215579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 216579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 217579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case llvm::Triple::x86: 218579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case llvm::Triple::x86_64: 219579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (CheckX86BuiltinFunctionCall(BuiltinID, TheCall)) 220579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 221579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 222579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson default: 223579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 224579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 225579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 226579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 227579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return move(TheCallResult); 228579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson} 229579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 230579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonbool Sema::CheckX86BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) { 231579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson switch (BuiltinID) { 232579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case X86::BI__builtin_ia32_palignr128: 233579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case X86::BI__builtin_ia32_palignr: { 234579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson llvm::APSInt Result; 235579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinConstantArg(TheCall, 2, Result)) 236579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return true; 237579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson break; 238579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 239579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 240579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 241579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson} 242579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 243579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson// Get the valid immediate range for the specified NEON type code. 244579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonstatic unsigned RFT(unsigned t, bool shift = false) { 245579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson bool quad = t & 0x10; 246579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 247579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson switch (t & 0x7) { 248579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case 0: // i8 249579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return shift ? 7 : (8 << (int)quad) - 1; 250579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case 1: // i16 251579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return shift ? 15 : (4 << (int)quad) - 1; 252579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case 2: // i32 253579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return shift ? 31 : (2 << (int)quad) - 1; 254579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case 3: // i64 255579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return shift ? 63 : (1 << (int)quad) - 1; 256579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case 4: // f32 257579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson assert(!shift && "cannot shift float types!"); 258579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return (2 << (int)quad) - 1; 259579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case 5: // poly8 260579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson assert(!shift && "cannot shift polynomial types!"); 261579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return (8 << (int)quad) - 1; 262579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case 6: // poly16 263579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson assert(!shift && "cannot shift polynomial types!"); 264579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return (4 << (int)quad) - 1; 265579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson case 7: // float16 266579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson assert(!shift && "cannot shift float types!"); 267579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return (4 << (int)quad) - 1; 268579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 269579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return 0; 270579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson} 271579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 272579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonbool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) { 273579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson llvm::APSInt Result; 274579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 275579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned mask = 0; 276579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned TV = 0; 277579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson switch (BuiltinID) { 278579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#define GET_NEON_OVERLOAD_CHECK 279579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/Basic/arm_neon.inc" 280579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#undef GET_NEON_OVERLOAD_CHECK 281579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 282579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 283579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // For NEON intrinsics which are overloaded on vector element type, validate 284579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // the immediate which specifies which variant to emit. 285579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (mask) { 286579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned ArgNo = TheCall->getNumArgs()-1; 287579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinConstantArg(TheCall, ArgNo, Result)) 288579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return true; 289579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 290579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson TV = Result.getLimitedValue(32); 291579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if ((TV > 31) || (mask & (1 << TV)) == 0) 292579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return Diag(TheCall->getLocStart(), diag::err_invalid_neon_type_code) 293579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson << TheCall->getArg(ArgNo)->getSourceRange(); 294579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 295579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 296579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // For NEON intrinsics which take an immediate value as part of the 297579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // instruction, range check them here. 298579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned i = 0, l = 0, u = 0; 299579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson switch (BuiltinID) { 300579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson default: return false; 301579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#define GET_NEON_IMMEDIATE_CHECK 302579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#include "clang/Basic/arm_neon.inc" 303579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#undef GET_NEON_IMMEDIATE_CHECK 304579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson }; 305579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 306579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Check that the immediate argument is actually a constant. 307579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (SemaBuiltinConstantArg(TheCall, i, Result)) 308579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return true; 309579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 310579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Range check against the upper/lower values for this isntruction. 311579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson unsigned Val = Result.getZExtValue(); 312579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (Val < l || Val > (u + l)) 313579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 314579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson << llvm::utostr(l) << llvm::utostr(u+l) 315579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson << TheCall->getArg(i)->getSourceRange(); 316579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 317579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 318579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson} 319579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 320579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// CheckFunctionCall - Check a direct function call for various correctness 321579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// and safety properties not strictly enforced by the C type system. 322579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonbool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall) { 323579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Get the IdentifierInfo* for the called function. 324579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson IdentifierInfo *FnInfo = FDecl->getIdentifier(); 325579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 326579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // None of the checks below are needed for functions that don't have 327579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // simple names (e.g., C++ conversion functions). 328579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (!FnInfo) 329579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 330579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 331579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // FIXME: This mechanism should be abstracted to be less fragile and 332579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // more efficient. For example, just map function ids to custom 333579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // handlers. 334579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 335579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Printf checking. 336579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (const FormatAttr *Format = FDecl->getAttr<FormatAttr>()) { 337579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson const bool b = Format->getType() == "scanf"; 338579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (b || CheckablePrintfAttr(Format, TheCall)) { 339579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson bool HasVAListArg = Format->getFirstArg() == 0; 340579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson CheckPrintfScanfArguments(TheCall, HasVAListArg, 341579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Format->getFormatIdx() - 1, 342579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson HasVAListArg ? 0 : Format->getFirstArg() - 1, 343579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson !b); 344579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 345579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 346579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 347579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson for (const NonNullAttr *NonNull = FDecl->getAttr<NonNullAttr>(); NonNull; 348579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson NonNull = NonNull->getNext<NonNullAttr>()) 349579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson CheckNonNullArguments(NonNull, TheCall); 350579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 351579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 352579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson} 353579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 354579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonbool Sema::CheckBlockCall(NamedDecl *NDecl, CallExpr *TheCall) { 355579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Printf checking. 356579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson const FormatAttr *Format = NDecl->getAttr<FormatAttr>(); 357579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (!Format) 358579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 359579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 360579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson const VarDecl *V = dyn_cast<VarDecl>(NDecl); 361579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (!V) 362579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 363579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 364579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson QualType Ty = V->getType(); 365579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (!Ty->isBlockPointerType()) 366579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 367579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 368579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson const bool b = Format->getType() == "scanf"; 369579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (!b && !CheckablePrintfAttr(Format, TheCall)) 370579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 371579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 372579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson bool HasVAListArg = Format->getFirstArg() == 0; 373579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson CheckPrintfScanfArguments(TheCall, HasVAListArg, Format->getFormatIdx() - 1, 374579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson HasVAListArg ? 0 : Format->getFirstArg() - 1, !b); 375579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 376579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return false; 377579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson} 378579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 379579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// SemaBuiltinAtomicOverloaded - We have a call to a function like 380579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// __sync_fetch_and_add, which is an overloaded function based on the pointer 381579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// type of its first argument. The main ActOnCallExpr routines have already 382579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// promoted the types of arguments because all of these calls are prototyped as 383579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// void(...). 384579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// 385579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// This function goes through and does final semantic checking for these 386579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/// builtins, 387579d7739c53a2707ad711a2d2cae46d7d782f06Jesse WilsonSema::OwningExprResult 388579d7739c53a2707ad711a2d2cae46d7d782f06Jesse WilsonSema::SemaBuiltinAtomicOverloaded(OwningExprResult TheCallResult) { 389579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson CallExpr *TheCall = (CallExpr *)TheCallResult.get(); 390579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts()); 391579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl()); 392579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 393579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Ensure that we have at least one argument to do type inference from. 394579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (TheCall->getNumArgs() < 1) { 395579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least) 396579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson << 0 << 1 << TheCall->getNumArgs() 397579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson << TheCall->getCallee()->getSourceRange(); 398579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 399579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 400579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 401579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Inspect the first argument of the atomic builtin. This should always be 402579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // a pointer type, whose element is an integral scalar or pointer type. 403579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Because it is a pointer type, we don't have to worry about any implicit 404579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // casts here. 405579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // FIXME: We don't allow floating point scalars as input. 406579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Expr *FirstArg = TheCall->getArg(0); 407579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (!FirstArg->getType()->isPointerType()) { 408579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer) 409579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson << FirstArg->getType() << FirstArg->getSourceRange(); 410579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 411579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 412579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 413579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson QualType ValType = 414579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson FirstArg->getType()->getAs<PointerType>()->getPointeeType(); 415579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (!ValType->isIntegerType() && !ValType->isPointerType() && 416579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson !ValType->isBlockPointerType()) { 417579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intptr) 418579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson << FirstArg->getType() << FirstArg->getSourceRange(); 419579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return ExprError(); 420579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 421579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 422579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // The majority of builtins return a value, but a few have special return 423579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // types, so allow them to override appropriately below. 424579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson QualType ResultType = ValType; 425579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 426579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // We need to figure out which concrete builtin this maps onto. For example, 427579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // __sync_fetch_and_add with a 2 byte object turns into 428579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // __sync_fetch_and_add_2. 429579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#define BUILTIN_ROW(x) \ 430579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \ 431579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Builtin::BI##x##_8, Builtin::BI##x##_16 } 432579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 433579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson static const unsigned BuiltinIndices[][5] = { 434579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_fetch_and_add), 435579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_fetch_and_sub), 436579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_fetch_and_or), 437579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_fetch_and_and), 438579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_fetch_and_xor), 439579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 440579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_add_and_fetch), 441579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_sub_and_fetch), 442579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_and_and_fetch), 443579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_or_and_fetch), 444579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_xor_and_fetch), 445579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 446579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_val_compare_and_swap), 447579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_bool_compare_and_swap), 448579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_lock_test_and_set), 449579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson BUILTIN_ROW(__sync_lock_release) 450579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson }; 451579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson#undef BUILTIN_ROW 452579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 453579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson // Determine the index of the size. 454 unsigned SizeIndex; 455 switch (Context.getTypeSizeInChars(ValType).getQuantity()) { 456 case 1: SizeIndex = 0; break; 457 case 2: SizeIndex = 1; break; 458 case 4: SizeIndex = 2; break; 459 case 8: SizeIndex = 3; break; 460 case 16: SizeIndex = 4; break; 461 default: 462 Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size) 463 << FirstArg->getType() << FirstArg->getSourceRange(); 464 return ExprError(); 465 } 466 467 // Each of these builtins has one pointer argument, followed by some number of 468 // values (0, 1 or 2) followed by a potentially empty varags list of stuff 469 // that we ignore. Find out which row of BuiltinIndices to read from as well 470 // as the number of fixed args. 471 unsigned BuiltinID = FDecl->getBuiltinID(); 472 unsigned BuiltinIndex, NumFixed = 1; 473 switch (BuiltinID) { 474 default: assert(0 && "Unknown overloaded atomic builtin!"); 475 case Builtin::BI__sync_fetch_and_add: BuiltinIndex = 0; break; 476 case Builtin::BI__sync_fetch_and_sub: BuiltinIndex = 1; break; 477 case Builtin::BI__sync_fetch_and_or: BuiltinIndex = 2; break; 478 case Builtin::BI__sync_fetch_and_and: BuiltinIndex = 3; break; 479 case Builtin::BI__sync_fetch_and_xor: BuiltinIndex = 4; break; 480 481 case Builtin::BI__sync_add_and_fetch: BuiltinIndex = 5; break; 482 case Builtin::BI__sync_sub_and_fetch: BuiltinIndex = 6; break; 483 case Builtin::BI__sync_and_and_fetch: BuiltinIndex = 7; break; 484 case Builtin::BI__sync_or_and_fetch: BuiltinIndex = 8; break; 485 case Builtin::BI__sync_xor_and_fetch: BuiltinIndex = 9; break; 486 487 case Builtin::BI__sync_val_compare_and_swap: 488 BuiltinIndex = 10; 489 NumFixed = 2; 490 break; 491 case Builtin::BI__sync_bool_compare_and_swap: 492 BuiltinIndex = 11; 493 NumFixed = 2; 494 ResultType = Context.BoolTy; 495 break; 496 case Builtin::BI__sync_lock_test_and_set: BuiltinIndex = 12; break; 497 case Builtin::BI__sync_lock_release: 498 BuiltinIndex = 13; 499 NumFixed = 0; 500 ResultType = Context.VoidTy; 501 break; 502 } 503 504 // Now that we know how many fixed arguments we expect, first check that we 505 // have at least that many. 506 if (TheCall->getNumArgs() < 1+NumFixed) { 507 Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least) 508 << 0 << 1+NumFixed << TheCall->getNumArgs() 509 << TheCall->getCallee()->getSourceRange(); 510 return ExprError(); 511 } 512 513 // Get the decl for the concrete builtin from this, we can tell what the 514 // concrete integer type we should convert to is. 515 unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex]; 516 const char *NewBuiltinName = Context.BuiltinInfo.GetName(NewBuiltinID); 517 IdentifierInfo *NewBuiltinII = PP.getIdentifierInfo(NewBuiltinName); 518 FunctionDecl *NewBuiltinDecl = 519 cast<FunctionDecl>(LazilyCreateBuiltin(NewBuiltinII, NewBuiltinID, 520 TUScope, false, DRE->getLocStart())); 521 522 // The first argument is by definition correct, we use it's type as the type 523 // of the entire operation. Walk the remaining arguments promoting them to 524 // the deduced value type. 525 for (unsigned i = 0; i != NumFixed; ++i) { 526 Expr *Arg = TheCall->getArg(i+1); 527 528 // If the argument is an implicit cast, then there was a promotion due to 529 // "...", just remove it now. 530 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) { 531 Arg = ICE->getSubExpr(); 532 ICE->setSubExpr(0); 533 ICE->Destroy(Context); 534 TheCall->setArg(i+1, Arg); 535 } 536 537 // GCC does an implicit conversion to the pointer or integer ValType. This 538 // can fail in some cases (1i -> int**), check for this error case now. 539 CastExpr::CastKind Kind = CastExpr::CK_Unknown; 540 CXXBaseSpecifierArray BasePath; 541 if (CheckCastTypes(Arg->getSourceRange(), ValType, Arg, Kind, BasePath)) 542 return ExprError(); 543 544 // Okay, we have something that *can* be converted to the right type. Check 545 // to see if there is a potentially weird extension going on here. This can 546 // happen when you do an atomic operation on something like an char* and 547 // pass in 42. The 42 gets converted to char. This is even more strange 548 // for things like 45.123 -> char, etc. 549 // FIXME: Do this check. 550 ImpCastExprToType(Arg, ValType, Kind); 551 TheCall->setArg(i+1, Arg); 552 } 553 554 // Switch the DeclRefExpr to refer to the new decl. 555 DRE->setDecl(NewBuiltinDecl); 556 DRE->setType(NewBuiltinDecl->getType()); 557 558 // Set the callee in the CallExpr. 559 // FIXME: This leaks the original parens and implicit casts. 560 Expr *PromotedCall = DRE; 561 UsualUnaryConversions(PromotedCall); 562 TheCall->setCallee(PromotedCall); 563 564 // Change the result type of the call to match the original value type. This 565 // is arbitrary, but the codegen for these builtins ins design to handle it 566 // gracefully. 567 TheCall->setType(ResultType); 568 569 return move(TheCallResult); 570} 571 572 573/// CheckObjCString - Checks that the argument to the builtin 574/// CFString constructor is correct 575/// FIXME: GCC currently emits the following warning: 576/// "warning: input conversion stopped due to an input byte that does not 577/// belong to the input codeset UTF-8" 578/// Note: It might also make sense to do the UTF-16 conversion here (would 579/// simplify the backend). 580bool Sema::CheckObjCString(Expr *Arg) { 581 Arg = Arg->IgnoreParenCasts(); 582 StringLiteral *Literal = dyn_cast<StringLiteral>(Arg); 583 584 if (!Literal || Literal->isWide()) { 585 Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant) 586 << Arg->getSourceRange(); 587 return true; 588 } 589 590 const char *Data = Literal->getStrData(); 591 unsigned Length = Literal->getByteLength(); 592 593 for (unsigned i = 0; i < Length; ++i) { 594 if (!Data[i]) { 595 Diag(getLocationOfStringLiteralByte(Literal, i), 596 diag::warn_cfstring_literal_contains_nul_character) 597 << Arg->getSourceRange(); 598 break; 599 } 600 } 601 602 return false; 603} 604 605/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity. 606/// Emit an error and return true on failure, return false on success. 607bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) { 608 Expr *Fn = TheCall->getCallee(); 609 if (TheCall->getNumArgs() > 2) { 610 Diag(TheCall->getArg(2)->getLocStart(), 611 diag::err_typecheck_call_too_many_args) 612 << 0 /*function call*/ << 2 << TheCall->getNumArgs() 613 << Fn->getSourceRange() 614 << SourceRange(TheCall->getArg(2)->getLocStart(), 615 (*(TheCall->arg_end()-1))->getLocEnd()); 616 return true; 617 } 618 619 if (TheCall->getNumArgs() < 2) { 620 return Diag(TheCall->getLocEnd(), 621 diag::err_typecheck_call_too_few_args_at_least) 622 << 0 /*function call*/ << 2 << TheCall->getNumArgs(); 623 } 624 625 // Determine whether the current function is variadic or not. 626 BlockScopeInfo *CurBlock = getCurBlock(); 627 bool isVariadic; 628 if (CurBlock) 629 isVariadic = CurBlock->TheDecl->isVariadic(); 630 else if (FunctionDecl *FD = getCurFunctionDecl()) 631 isVariadic = FD->isVariadic(); 632 else 633 isVariadic = getCurMethodDecl()->isVariadic(); 634 635 if (!isVariadic) { 636 Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function); 637 return true; 638 } 639 640 // Verify that the second argument to the builtin is the last argument of the 641 // current function or method. 642 bool SecondArgIsLastNamedArgument = false; 643 const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts(); 644 645 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) { 646 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) { 647 // FIXME: This isn't correct for methods (results in bogus warning). 648 // Get the last formal in the current function. 649 const ParmVarDecl *LastArg; 650 if (CurBlock) 651 LastArg = *(CurBlock->TheDecl->param_end()-1); 652 else if (FunctionDecl *FD = getCurFunctionDecl()) 653 LastArg = *(FD->param_end()-1); 654 else 655 LastArg = *(getCurMethodDecl()->param_end()-1); 656 SecondArgIsLastNamedArgument = PV == LastArg; 657 } 658 } 659 660 if (!SecondArgIsLastNamedArgument) 661 Diag(TheCall->getArg(1)->getLocStart(), 662 diag::warn_second_parameter_of_va_start_not_last_named_argument); 663 return false; 664} 665 666/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and 667/// friends. This is declared to take (...), so we have to check everything. 668bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) { 669 if (TheCall->getNumArgs() < 2) 670 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 671 << 0 << 2 << TheCall->getNumArgs()/*function call*/; 672 if (TheCall->getNumArgs() > 2) 673 return Diag(TheCall->getArg(2)->getLocStart(), 674 diag::err_typecheck_call_too_many_args) 675 << 0 /*function call*/ << 2 << TheCall->getNumArgs() 676 << SourceRange(TheCall->getArg(2)->getLocStart(), 677 (*(TheCall->arg_end()-1))->getLocEnd()); 678 679 Expr *OrigArg0 = TheCall->getArg(0); 680 Expr *OrigArg1 = TheCall->getArg(1); 681 682 // Do standard promotions between the two arguments, returning their common 683 // type. 684 QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false); 685 686 // Make sure any conversions are pushed back into the call; this is 687 // type safe since unordered compare builtins are declared as "_Bool 688 // foo(...)". 689 TheCall->setArg(0, OrigArg0); 690 TheCall->setArg(1, OrigArg1); 691 692 if (OrigArg0->isTypeDependent() || OrigArg1->isTypeDependent()) 693 return false; 694 695 // If the common type isn't a real floating type, then the arguments were 696 // invalid for this operation. 697 if (!Res->isRealFloatingType()) 698 return Diag(OrigArg0->getLocStart(), 699 diag::err_typecheck_call_invalid_ordered_compare) 700 << OrigArg0->getType() << OrigArg1->getType() 701 << SourceRange(OrigArg0->getLocStart(), OrigArg1->getLocEnd()); 702 703 return false; 704} 705 706/// SemaBuiltinSemaBuiltinFPClassification - Handle functions like 707/// __builtin_isnan and friends. This is declared to take (...), so we have 708/// to check everything. We expect the last argument to be a floating point 709/// value. 710bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) { 711 if (TheCall->getNumArgs() < NumArgs) 712 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 713 << 0 << NumArgs << TheCall->getNumArgs()/*function call*/; 714 if (TheCall->getNumArgs() > NumArgs) 715 return Diag(TheCall->getArg(NumArgs)->getLocStart(), 716 diag::err_typecheck_call_too_many_args) 717 << 0 /*function call*/ << NumArgs << TheCall->getNumArgs() 718 << SourceRange(TheCall->getArg(NumArgs)->getLocStart(), 719 (*(TheCall->arg_end()-1))->getLocEnd()); 720 721 Expr *OrigArg = TheCall->getArg(NumArgs-1); 722 723 if (OrigArg->isTypeDependent()) 724 return false; 725 726 // This operation requires a non-_Complex floating-point number. 727 if (!OrigArg->getType()->isRealFloatingType()) 728 return Diag(OrigArg->getLocStart(), 729 diag::err_typecheck_call_invalid_unary_fp) 730 << OrigArg->getType() << OrigArg->getSourceRange(); 731 732 // If this is an implicit conversion from float -> double, remove it. 733 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(OrigArg)) { 734 Expr *CastArg = Cast->getSubExpr(); 735 if (CastArg->getType()->isSpecificBuiltinType(BuiltinType::Float)) { 736 assert(Cast->getType()->isSpecificBuiltinType(BuiltinType::Double) && 737 "promotion from float to double is the only expected cast here"); 738 Cast->setSubExpr(0); 739 Cast->Destroy(Context); 740 TheCall->setArg(NumArgs-1, CastArg); 741 OrigArg = CastArg; 742 } 743 } 744 745 return false; 746} 747 748/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector. 749// This is declared to take (...), so we have to check everything. 750Action::OwningExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) { 751 if (TheCall->getNumArgs() < 2) 752 return ExprError(Diag(TheCall->getLocEnd(), 753 diag::err_typecheck_call_too_few_args_at_least) 754 << 0 /*function call*/ << 2 << TheCall->getNumArgs() 755 << TheCall->getSourceRange()); 756 757 // Determine which of the following types of shufflevector we're checking: 758 // 1) unary, vector mask: (lhs, mask) 759 // 2) binary, vector mask: (lhs, rhs, mask) 760 // 3) binary, scalar mask: (lhs, rhs, index, ..., index) 761 QualType resType = TheCall->getArg(0)->getType(); 762 unsigned numElements = 0; 763 764 if (!TheCall->getArg(0)->isTypeDependent() && 765 !TheCall->getArg(1)->isTypeDependent()) { 766 QualType LHSType = TheCall->getArg(0)->getType(); 767 QualType RHSType = TheCall->getArg(1)->getType(); 768 769 if (!LHSType->isVectorType() || !RHSType->isVectorType()) { 770 Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector) 771 << SourceRange(TheCall->getArg(0)->getLocStart(), 772 TheCall->getArg(1)->getLocEnd()); 773 return ExprError(); 774 } 775 776 numElements = LHSType->getAs<VectorType>()->getNumElements(); 777 unsigned numResElements = TheCall->getNumArgs() - 2; 778 779 // Check to see if we have a call with 2 vector arguments, the unary shuffle 780 // with mask. If so, verify that RHS is an integer vector type with the 781 // same number of elts as lhs. 782 if (TheCall->getNumArgs() == 2) { 783 if (!RHSType->isIntegerType() || 784 RHSType->getAs<VectorType>()->getNumElements() != numElements) 785 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector) 786 << SourceRange(TheCall->getArg(1)->getLocStart(), 787 TheCall->getArg(1)->getLocEnd()); 788 numResElements = numElements; 789 } 790 else if (!Context.hasSameUnqualifiedType(LHSType, RHSType)) { 791 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector) 792 << SourceRange(TheCall->getArg(0)->getLocStart(), 793 TheCall->getArg(1)->getLocEnd()); 794 return ExprError(); 795 } else if (numElements != numResElements) { 796 QualType eltType = LHSType->getAs<VectorType>()->getElementType(); 797 resType = Context.getVectorType(eltType, numResElements, 798 VectorType::NotAltiVec); 799 } 800 } 801 802 for (unsigned i = 2; i < TheCall->getNumArgs(); i++) { 803 if (TheCall->getArg(i)->isTypeDependent() || 804 TheCall->getArg(i)->isValueDependent()) 805 continue; 806 807 llvm::APSInt Result(32); 808 if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context)) 809 return ExprError(Diag(TheCall->getLocStart(), 810 diag::err_shufflevector_nonconstant_argument) 811 << TheCall->getArg(i)->getSourceRange()); 812 813 if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2) 814 return ExprError(Diag(TheCall->getLocStart(), 815 diag::err_shufflevector_argument_too_large) 816 << TheCall->getArg(i)->getSourceRange()); 817 } 818 819 llvm::SmallVector<Expr*, 32> exprs; 820 821 for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) { 822 exprs.push_back(TheCall->getArg(i)); 823 TheCall->setArg(i, 0); 824 } 825 826 return Owned(new (Context) ShuffleVectorExpr(Context, exprs.begin(), 827 exprs.size(), resType, 828 TheCall->getCallee()->getLocStart(), 829 TheCall->getRParenLoc())); 830} 831 832/// SemaBuiltinPrefetch - Handle __builtin_prefetch. 833// This is declared to take (const void*, ...) and can take two 834// optional constant int args. 835bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) { 836 unsigned NumArgs = TheCall->getNumArgs(); 837 838 if (NumArgs > 3) 839 return Diag(TheCall->getLocEnd(), 840 diag::err_typecheck_call_too_many_args_at_most) 841 << 0 /*function call*/ << 3 << NumArgs 842 << TheCall->getSourceRange(); 843 844 // Argument 0 is checked for us and the remaining arguments must be 845 // constant integers. 846 for (unsigned i = 1; i != NumArgs; ++i) { 847 Expr *Arg = TheCall->getArg(i); 848 849 llvm::APSInt Result; 850 if (SemaBuiltinConstantArg(TheCall, i, Result)) 851 return true; 852 853 // FIXME: gcc issues a warning and rewrites these to 0. These 854 // seems especially odd for the third argument since the default 855 // is 3. 856 if (i == 1) { 857 if (Result.getLimitedValue() > 1) 858 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 859 << "0" << "1" << Arg->getSourceRange(); 860 } else { 861 if (Result.getLimitedValue() > 3) 862 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 863 << "0" << "3" << Arg->getSourceRange(); 864 } 865 } 866 867 return false; 868} 869 870/// SemaBuiltinConstantArg - Handle a check if argument ArgNum of CallExpr 871/// TheCall is a constant expression. 872bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum, 873 llvm::APSInt &Result) { 874 Expr *Arg = TheCall->getArg(ArgNum); 875 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts()); 876 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl()); 877 878 if (Arg->isTypeDependent() || Arg->isValueDependent()) return false; 879 880 if (!Arg->isIntegerConstantExpr(Result, Context)) 881 return Diag(TheCall->getLocStart(), diag::err_constant_integer_arg_type) 882 << FDecl->getDeclName() << Arg->getSourceRange(); 883 884 return false; 885} 886 887/// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr, 888/// int type). This simply type checks that type is one of the defined 889/// constants (0-3). 890// For compatability check 0-3, llvm only handles 0 and 2. 891bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) { 892 llvm::APSInt Result; 893 894 // Check constant-ness first. 895 if (SemaBuiltinConstantArg(TheCall, 1, Result)) 896 return true; 897 898 Expr *Arg = TheCall->getArg(1); 899 if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) { 900 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 901 << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 902 } 903 904 return false; 905} 906 907/// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val). 908/// This checks that val is a constant 1. 909bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) { 910 Expr *Arg = TheCall->getArg(1); 911 llvm::APSInt Result; 912 913 // TODO: This is less than ideal. Overload this to take a value. 914 if (SemaBuiltinConstantArg(TheCall, 1, Result)) 915 return true; 916 917 if (Result != 1) 918 return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val) 919 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 920 921 return false; 922} 923 924// Handle i > 1 ? "x" : "y", recursivelly 925bool Sema::SemaCheckStringLiteral(const Expr *E, const CallExpr *TheCall, 926 bool HasVAListArg, 927 unsigned format_idx, unsigned firstDataArg, 928 bool isPrintf) { 929 930 if (E->isTypeDependent() || E->isValueDependent()) 931 return false; 932 933 switch (E->getStmtClass()) { 934 case Stmt::ConditionalOperatorClass: { 935 const ConditionalOperator *C = cast<ConditionalOperator>(E); 936 return SemaCheckStringLiteral(C->getTrueExpr(), TheCall, HasVAListArg, 937 format_idx, firstDataArg, isPrintf) 938 && SemaCheckStringLiteral(C->getRHS(), TheCall, HasVAListArg, 939 format_idx, firstDataArg, isPrintf); 940 } 941 942 case Stmt::ImplicitCastExprClass: { 943 const ImplicitCastExpr *Expr = cast<ImplicitCastExpr>(E); 944 return SemaCheckStringLiteral(Expr->getSubExpr(), TheCall, HasVAListArg, 945 format_idx, firstDataArg, isPrintf); 946 } 947 948 case Stmt::ParenExprClass: { 949 const ParenExpr *Expr = cast<ParenExpr>(E); 950 return SemaCheckStringLiteral(Expr->getSubExpr(), TheCall, HasVAListArg, 951 format_idx, firstDataArg, isPrintf); 952 } 953 954 case Stmt::DeclRefExprClass: { 955 const DeclRefExpr *DR = cast<DeclRefExpr>(E); 956 957 // As an exception, do not flag errors for variables binding to 958 // const string literals. 959 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) { 960 bool isConstant = false; 961 QualType T = DR->getType(); 962 963 if (const ArrayType *AT = Context.getAsArrayType(T)) { 964 isConstant = AT->getElementType().isConstant(Context); 965 } else if (const PointerType *PT = T->getAs<PointerType>()) { 966 isConstant = T.isConstant(Context) && 967 PT->getPointeeType().isConstant(Context); 968 } 969 970 if (isConstant) { 971 if (const Expr *Init = VD->getAnyInitializer()) 972 return SemaCheckStringLiteral(Init, TheCall, 973 HasVAListArg, format_idx, firstDataArg, 974 isPrintf); 975 } 976 977 // For vprintf* functions (i.e., HasVAListArg==true), we add a 978 // special check to see if the format string is a function parameter 979 // of the function calling the printf function. If the function 980 // has an attribute indicating it is a printf-like function, then we 981 // should suppress warnings concerning non-literals being used in a call 982 // to a vprintf function. For example: 983 // 984 // void 985 // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){ 986 // va_list ap; 987 // va_start(ap, fmt); 988 // vprintf(fmt, ap); // Do NOT emit a warning about "fmt". 989 // ... 990 // 991 // 992 // FIXME: We don't have full attribute support yet, so just check to see 993 // if the argument is a DeclRefExpr that references a parameter. We'll 994 // add proper support for checking the attribute later. 995 if (HasVAListArg) 996 if (isa<ParmVarDecl>(VD)) 997 return true; 998 } 999 1000 return false; 1001 } 1002 1003 case Stmt::CallExprClass: { 1004 const CallExpr *CE = cast<CallExpr>(E); 1005 if (const ImplicitCastExpr *ICE 1006 = dyn_cast<ImplicitCastExpr>(CE->getCallee())) { 1007 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) { 1008 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) { 1009 if (const FormatArgAttr *FA = FD->getAttr<FormatArgAttr>()) { 1010 unsigned ArgIndex = FA->getFormatIdx(); 1011 const Expr *Arg = CE->getArg(ArgIndex - 1); 1012 1013 return SemaCheckStringLiteral(Arg, TheCall, HasVAListArg, 1014 format_idx, firstDataArg, isPrintf); 1015 } 1016 } 1017 } 1018 } 1019 1020 return false; 1021 } 1022 case Stmt::ObjCStringLiteralClass: 1023 case Stmt::StringLiteralClass: { 1024 const StringLiteral *StrE = NULL; 1025 1026 if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E)) 1027 StrE = ObjCFExpr->getString(); 1028 else 1029 StrE = cast<StringLiteral>(E); 1030 1031 if (StrE) { 1032 CheckFormatString(StrE, E, TheCall, HasVAListArg, format_idx, 1033 firstDataArg, isPrintf); 1034 return true; 1035 } 1036 1037 return false; 1038 } 1039 1040 default: 1041 return false; 1042 } 1043} 1044 1045void 1046Sema::CheckNonNullArguments(const NonNullAttr *NonNull, 1047 const CallExpr *TheCall) { 1048 for (NonNullAttr::iterator i = NonNull->begin(), e = NonNull->end(); 1049 i != e; ++i) { 1050 const Expr *ArgExpr = TheCall->getArg(*i); 1051 if (ArgExpr->isNullPointerConstant(Context, 1052 Expr::NPC_ValueDependentIsNotNull)) 1053 Diag(TheCall->getCallee()->getLocStart(), diag::warn_null_arg) 1054 << ArgExpr->getSourceRange(); 1055 } 1056} 1057 1058/// CheckPrintfScanfArguments - Check calls to printf and scanf (and similar 1059/// functions) for correct use of format strings. 1060void 1061Sema::CheckPrintfScanfArguments(const CallExpr *TheCall, bool HasVAListArg, 1062 unsigned format_idx, unsigned firstDataArg, 1063 bool isPrintf) { 1064 1065 const Expr *Fn = TheCall->getCallee(); 1066 1067 // The way the format attribute works in GCC, the implicit this argument 1068 // of member functions is counted. However, it doesn't appear in our own 1069 // lists, so decrement format_idx in that case. 1070 if (isa<CXXMemberCallExpr>(TheCall)) { 1071 // Catch a format attribute mistakenly referring to the object argument. 1072 if (format_idx == 0) 1073 return; 1074 --format_idx; 1075 if(firstDataArg != 0) 1076 --firstDataArg; 1077 } 1078 1079 // CHECK: printf/scanf-like function is called with no format string. 1080 if (format_idx >= TheCall->getNumArgs()) { 1081 Diag(TheCall->getRParenLoc(), diag::warn_missing_format_string) 1082 << Fn->getSourceRange(); 1083 return; 1084 } 1085 1086 const Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts(); 1087 1088 // CHECK: format string is not a string literal. 1089 // 1090 // Dynamically generated format strings are difficult to 1091 // automatically vet at compile time. Requiring that format strings 1092 // are string literals: (1) permits the checking of format strings by 1093 // the compiler and thereby (2) can practically remove the source of 1094 // many format string exploits. 1095 1096 // Format string can be either ObjC string (e.g. @"%d") or 1097 // C string (e.g. "%d") 1098 // ObjC string uses the same format specifiers as C string, so we can use 1099 // the same format string checking logic for both ObjC and C strings. 1100 if (SemaCheckStringLiteral(OrigFormatExpr, TheCall, HasVAListArg, format_idx, 1101 firstDataArg, isPrintf)) 1102 return; // Literal format string found, check done! 1103 1104 // If there are no arguments specified, warn with -Wformat-security, otherwise 1105 // warn only with -Wformat-nonliteral. 1106 if (TheCall->getNumArgs() == format_idx+1) 1107 Diag(TheCall->getArg(format_idx)->getLocStart(), 1108 diag::warn_format_nonliteral_noargs) 1109 << OrigFormatExpr->getSourceRange(); 1110 else 1111 Diag(TheCall->getArg(format_idx)->getLocStart(), 1112 diag::warn_format_nonliteral) 1113 << OrigFormatExpr->getSourceRange(); 1114} 1115 1116namespace { 1117class CheckFormatHandler : public analyze_format_string::FormatStringHandler { 1118protected: 1119 Sema &S; 1120 const StringLiteral *FExpr; 1121 const Expr *OrigFormatExpr; 1122 const unsigned FirstDataArg; 1123 const unsigned NumDataArgs; 1124 const bool IsObjCLiteral; 1125 const char *Beg; // Start of format string. 1126 const bool HasVAListArg; 1127 const CallExpr *TheCall; 1128 unsigned FormatIdx; 1129 llvm::BitVector CoveredArgs; 1130 bool usesPositionalArgs; 1131 bool atFirstArg; 1132public: 1133 CheckFormatHandler(Sema &s, const StringLiteral *fexpr, 1134 const Expr *origFormatExpr, unsigned firstDataArg, 1135 unsigned numDataArgs, bool isObjCLiteral, 1136 const char *beg, bool hasVAListArg, 1137 const CallExpr *theCall, unsigned formatIdx) 1138 : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr), 1139 FirstDataArg(firstDataArg), 1140 NumDataArgs(numDataArgs), 1141 IsObjCLiteral(isObjCLiteral), Beg(beg), 1142 HasVAListArg(hasVAListArg), 1143 TheCall(theCall), FormatIdx(formatIdx), 1144 usesPositionalArgs(false), atFirstArg(true) { 1145 CoveredArgs.resize(numDataArgs); 1146 CoveredArgs.reset(); 1147 } 1148 1149 void DoneProcessing(); 1150 1151 void HandleIncompleteSpecifier(const char *startSpecifier, 1152 unsigned specifierLen); 1153 1154 virtual void HandleInvalidPosition(const char *startSpecifier, 1155 unsigned specifierLen, 1156 analyze_format_string::PositionContext p); 1157 1158 virtual void HandleZeroPosition(const char *startPos, unsigned posLen); 1159 1160 void HandleNullChar(const char *nullCharacter); 1161 1162protected: 1163 bool HandleInvalidConversionSpecifier(unsigned argIndex, SourceLocation Loc, 1164 const char *startSpec, 1165 unsigned specifierLen, 1166 const char *csStart, unsigned csLen); 1167 1168 SourceRange getFormatStringRange(); 1169 CharSourceRange getSpecifierRange(const char *startSpecifier, 1170 unsigned specifierLen); 1171 SourceLocation getLocationOfByte(const char *x); 1172 1173 const Expr *getDataArg(unsigned i) const; 1174}; 1175} 1176 1177SourceRange CheckFormatHandler::getFormatStringRange() { 1178 return OrigFormatExpr->getSourceRange(); 1179} 1180 1181CharSourceRange CheckFormatHandler:: 1182getSpecifierRange(const char *startSpecifier, unsigned specifierLen) { 1183 SourceLocation Start = getLocationOfByte(startSpecifier); 1184 SourceLocation End = getLocationOfByte(startSpecifier + specifierLen - 1); 1185 1186 // Advance the end SourceLocation by one due to half-open ranges. 1187 End = End.getFileLocWithOffset(1); 1188 1189 return CharSourceRange::getCharRange(Start, End); 1190} 1191 1192SourceLocation CheckFormatHandler::getLocationOfByte(const char *x) { 1193 return S.getLocationOfStringLiteralByte(FExpr, x - Beg); 1194} 1195 1196void CheckFormatHandler::HandleIncompleteSpecifier(const char *startSpecifier, 1197 unsigned specifierLen){ 1198 SourceLocation Loc = getLocationOfByte(startSpecifier); 1199 S.Diag(Loc, diag::warn_printf_incomplete_specifier) 1200 << getSpecifierRange(startSpecifier, specifierLen); 1201} 1202 1203void 1204CheckFormatHandler::HandleInvalidPosition(const char *startPos, unsigned posLen, 1205 analyze_format_string::PositionContext p) { 1206 SourceLocation Loc = getLocationOfByte(startPos); 1207 S.Diag(Loc, diag::warn_format_invalid_positional_specifier) 1208 << (unsigned) p << getSpecifierRange(startPos, posLen); 1209} 1210 1211void CheckFormatHandler::HandleZeroPosition(const char *startPos, 1212 unsigned posLen) { 1213 SourceLocation Loc = getLocationOfByte(startPos); 1214 S.Diag(Loc, diag::warn_format_zero_positional_specifier) 1215 << getSpecifierRange(startPos, posLen); 1216} 1217 1218void CheckFormatHandler::HandleNullChar(const char *nullCharacter) { 1219 // The presence of a null character is likely an error. 1220 S.Diag(getLocationOfByte(nullCharacter), 1221 diag::warn_printf_format_string_contains_null_char) 1222 << getFormatStringRange(); 1223} 1224 1225const Expr *CheckFormatHandler::getDataArg(unsigned i) const { 1226 return TheCall->getArg(FirstDataArg + i); 1227} 1228 1229void CheckFormatHandler::DoneProcessing() { 1230 // Does the number of data arguments exceed the number of 1231 // format conversions in the format string? 1232 if (!HasVAListArg) { 1233 // Find any arguments that weren't covered. 1234 CoveredArgs.flip(); 1235 signed notCoveredArg = CoveredArgs.find_first(); 1236 if (notCoveredArg >= 0) { 1237 assert((unsigned)notCoveredArg < NumDataArgs); 1238 S.Diag(getDataArg((unsigned) notCoveredArg)->getLocStart(), 1239 diag::warn_printf_data_arg_not_used) 1240 << getFormatStringRange(); 1241 } 1242 } 1243} 1244 1245bool 1246CheckFormatHandler::HandleInvalidConversionSpecifier(unsigned argIndex, 1247 SourceLocation Loc, 1248 const char *startSpec, 1249 unsigned specifierLen, 1250 const char *csStart, 1251 unsigned csLen) { 1252 1253 bool keepGoing = true; 1254 if (argIndex < NumDataArgs) { 1255 // Consider the argument coverered, even though the specifier doesn't 1256 // make sense. 1257 CoveredArgs.set(argIndex); 1258 } 1259 else { 1260 // If argIndex exceeds the number of data arguments we 1261 // don't issue a warning because that is just a cascade of warnings (and 1262 // they may have intended '%%' anyway). We don't want to continue processing 1263 // the format string after this point, however, as we will like just get 1264 // gibberish when trying to match arguments. 1265 keepGoing = false; 1266 } 1267 1268 S.Diag(Loc, diag::warn_format_invalid_conversion) 1269 << llvm::StringRef(csStart, csLen) 1270 << getSpecifierRange(startSpec, specifierLen); 1271 1272 return keepGoing; 1273} 1274 1275//===--- CHECK: Printf format string checking ------------------------------===// 1276 1277namespace { 1278class CheckPrintfHandler : public CheckFormatHandler { 1279public: 1280 CheckPrintfHandler(Sema &s, const StringLiteral *fexpr, 1281 const Expr *origFormatExpr, unsigned firstDataArg, 1282 unsigned numDataArgs, bool isObjCLiteral, 1283 const char *beg, bool hasVAListArg, 1284 const CallExpr *theCall, unsigned formatIdx) 1285 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg, 1286 numDataArgs, isObjCLiteral, beg, hasVAListArg, 1287 theCall, formatIdx) {} 1288 1289 1290 bool HandleInvalidPrintfConversionSpecifier( 1291 const analyze_printf::PrintfSpecifier &FS, 1292 const char *startSpecifier, 1293 unsigned specifierLen); 1294 1295 bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS, 1296 const char *startSpecifier, 1297 unsigned specifierLen); 1298 1299 bool HandleAmount(const analyze_format_string::OptionalAmount &Amt, unsigned k, 1300 const char *startSpecifier, unsigned specifierLen); 1301 void HandleInvalidAmount(const analyze_printf::PrintfSpecifier &FS, 1302 const analyze_printf::OptionalAmount &Amt, 1303 unsigned type, 1304 const char *startSpecifier, unsigned specifierLen); 1305 void HandleFlag(const analyze_printf::PrintfSpecifier &FS, 1306 const analyze_printf::OptionalFlag &flag, 1307 const char *startSpecifier, unsigned specifierLen); 1308 void HandleIgnoredFlag(const analyze_printf::PrintfSpecifier &FS, 1309 const analyze_printf::OptionalFlag &ignoredFlag, 1310 const analyze_printf::OptionalFlag &flag, 1311 const char *startSpecifier, unsigned specifierLen); 1312}; 1313} 1314 1315bool CheckPrintfHandler::HandleInvalidPrintfConversionSpecifier( 1316 const analyze_printf::PrintfSpecifier &FS, 1317 const char *startSpecifier, 1318 unsigned specifierLen) { 1319 const analyze_printf::PrintfConversionSpecifier &CS = 1320 FS.getConversionSpecifier(); 1321 1322 return HandleInvalidConversionSpecifier(FS.getArgIndex(), 1323 getLocationOfByte(CS.getStart()), 1324 startSpecifier, specifierLen, 1325 CS.getStart(), CS.getLength()); 1326} 1327 1328bool CheckPrintfHandler::HandleAmount( 1329 const analyze_format_string::OptionalAmount &Amt, 1330 unsigned k, const char *startSpecifier, 1331 unsigned specifierLen) { 1332 1333 if (Amt.hasDataArgument()) { 1334 if (!HasVAListArg) { 1335 unsigned argIndex = Amt.getArgIndex(); 1336 if (argIndex >= NumDataArgs) { 1337 S.Diag(getLocationOfByte(Amt.getStart()), 1338 diag::warn_printf_asterisk_missing_arg) 1339 << k << getSpecifierRange(startSpecifier, specifierLen); 1340 // Don't do any more checking. We will just emit 1341 // spurious errors. 1342 return false; 1343 } 1344 1345 // Type check the data argument. It should be an 'int'. 1346 // Although not in conformance with C99, we also allow the argument to be 1347 // an 'unsigned int' as that is a reasonably safe case. GCC also 1348 // doesn't emit a warning for that case. 1349 CoveredArgs.set(argIndex); 1350 const Expr *Arg = getDataArg(argIndex); 1351 QualType T = Arg->getType(); 1352 1353 const analyze_printf::ArgTypeResult &ATR = Amt.getArgType(S.Context); 1354 assert(ATR.isValid()); 1355 1356 if (!ATR.matchesType(S.Context, T)) { 1357 S.Diag(getLocationOfByte(Amt.getStart()), 1358 diag::warn_printf_asterisk_wrong_type) 1359 << k 1360 << ATR.getRepresentativeType(S.Context) << T 1361 << getSpecifierRange(startSpecifier, specifierLen) 1362 << Arg->getSourceRange(); 1363 // Don't do any more checking. We will just emit 1364 // spurious errors. 1365 return false; 1366 } 1367 } 1368 } 1369 return true; 1370} 1371 1372void CheckPrintfHandler::HandleInvalidAmount( 1373 const analyze_printf::PrintfSpecifier &FS, 1374 const analyze_printf::OptionalAmount &Amt, 1375 unsigned type, 1376 const char *startSpecifier, 1377 unsigned specifierLen) { 1378 const analyze_printf::PrintfConversionSpecifier &CS = 1379 FS.getConversionSpecifier(); 1380 switch (Amt.getHowSpecified()) { 1381 case analyze_printf::OptionalAmount::Constant: 1382 S.Diag(getLocationOfByte(Amt.getStart()), 1383 diag::warn_printf_nonsensical_optional_amount) 1384 << type 1385 << CS.toString() 1386 << getSpecifierRange(startSpecifier, specifierLen) 1387 << FixItHint::CreateRemoval(getSpecifierRange(Amt.getStart(), 1388 Amt.getConstantLength())); 1389 break; 1390 1391 default: 1392 S.Diag(getLocationOfByte(Amt.getStart()), 1393 diag::warn_printf_nonsensical_optional_amount) 1394 << type 1395 << CS.toString() 1396 << getSpecifierRange(startSpecifier, specifierLen); 1397 break; 1398 } 1399} 1400 1401void CheckPrintfHandler::HandleFlag(const analyze_printf::PrintfSpecifier &FS, 1402 const analyze_printf::OptionalFlag &flag, 1403 const char *startSpecifier, 1404 unsigned specifierLen) { 1405 // Warn about pointless flag with a fixit removal. 1406 const analyze_printf::PrintfConversionSpecifier &CS = 1407 FS.getConversionSpecifier(); 1408 S.Diag(getLocationOfByte(flag.getPosition()), 1409 diag::warn_printf_nonsensical_flag) 1410 << flag.toString() << CS.toString() 1411 << getSpecifierRange(startSpecifier, specifierLen) 1412 << FixItHint::CreateRemoval(getSpecifierRange(flag.getPosition(), 1)); 1413} 1414 1415void CheckPrintfHandler::HandleIgnoredFlag( 1416 const analyze_printf::PrintfSpecifier &FS, 1417 const analyze_printf::OptionalFlag &ignoredFlag, 1418 const analyze_printf::OptionalFlag &flag, 1419 const char *startSpecifier, 1420 unsigned specifierLen) { 1421 // Warn about ignored flag with a fixit removal. 1422 S.Diag(getLocationOfByte(ignoredFlag.getPosition()), 1423 diag::warn_printf_ignored_flag) 1424 << ignoredFlag.toString() << flag.toString() 1425 << getSpecifierRange(startSpecifier, specifierLen) 1426 << FixItHint::CreateRemoval(getSpecifierRange( 1427 ignoredFlag.getPosition(), 1)); 1428} 1429 1430bool 1431CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier 1432 &FS, 1433 const char *startSpecifier, 1434 unsigned specifierLen) { 1435 1436 using namespace analyze_format_string; 1437 using namespace analyze_printf; 1438 const PrintfConversionSpecifier &CS = FS.getConversionSpecifier(); 1439 1440 if (FS.consumesDataArgument()) { 1441 if (atFirstArg) { 1442 atFirstArg = false; 1443 usesPositionalArgs = FS.usesPositionalArg(); 1444 } 1445 else if (usesPositionalArgs != FS.usesPositionalArg()) { 1446 // Cannot mix-and-match positional and non-positional arguments. 1447 S.Diag(getLocationOfByte(CS.getStart()), 1448 diag::warn_format_mix_positional_nonpositional_args) 1449 << getSpecifierRange(startSpecifier, specifierLen); 1450 return false; 1451 } 1452 } 1453 1454 // First check if the field width, precision, and conversion specifier 1455 // have matching data arguments. 1456 if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0, 1457 startSpecifier, specifierLen)) { 1458 return false; 1459 } 1460 1461 if (!HandleAmount(FS.getPrecision(), /* precision */ 1, 1462 startSpecifier, specifierLen)) { 1463 return false; 1464 } 1465 1466 if (!CS.consumesDataArgument()) { 1467 // FIXME: Technically specifying a precision or field width here 1468 // makes no sense. Worth issuing a warning at some point. 1469 return true; 1470 } 1471 1472 // Consume the argument. 1473 unsigned argIndex = FS.getArgIndex(); 1474 if (argIndex < NumDataArgs) { 1475 // The check to see if the argIndex is valid will come later. 1476 // We set the bit here because we may exit early from this 1477 // function if we encounter some other error. 1478 CoveredArgs.set(argIndex); 1479 } 1480 1481 // Check for using an Objective-C specific conversion specifier 1482 // in a non-ObjC literal. 1483 if (!IsObjCLiteral && CS.isObjCArg()) { 1484 return HandleInvalidPrintfConversionSpecifier(FS, startSpecifier, 1485 specifierLen); 1486 } 1487 1488 // Check for invalid use of field width 1489 if (!FS.hasValidFieldWidth()) { 1490 HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 0, 1491 startSpecifier, specifierLen); 1492 } 1493 1494 // Check for invalid use of precision 1495 if (!FS.hasValidPrecision()) { 1496 HandleInvalidAmount(FS, FS.getPrecision(), /* precision */ 1, 1497 startSpecifier, specifierLen); 1498 } 1499 1500 // Check each flag does not conflict with any other component. 1501 if (!FS.hasValidLeadingZeros()) 1502 HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen); 1503 if (!FS.hasValidPlusPrefix()) 1504 HandleFlag(FS, FS.hasPlusPrefix(), startSpecifier, specifierLen); 1505 if (!FS.hasValidSpacePrefix()) 1506 HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen); 1507 if (!FS.hasValidAlternativeForm()) 1508 HandleFlag(FS, FS.hasAlternativeForm(), startSpecifier, specifierLen); 1509 if (!FS.hasValidLeftJustified()) 1510 HandleFlag(FS, FS.isLeftJustified(), startSpecifier, specifierLen); 1511 1512 // Check that flags are not ignored by another flag 1513 if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+' 1514 HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(), 1515 startSpecifier, specifierLen); 1516 if (FS.hasLeadingZeros() && FS.isLeftJustified()) // '0' ignored by '-' 1517 HandleIgnoredFlag(FS, FS.hasLeadingZeros(), FS.isLeftJustified(), 1518 startSpecifier, specifierLen); 1519 1520 // Check the length modifier is valid with the given conversion specifier. 1521 const LengthModifier &LM = FS.getLengthModifier(); 1522 if (!FS.hasValidLengthModifier()) 1523 S.Diag(getLocationOfByte(LM.getStart()), 1524 diag::warn_format_nonsensical_length) 1525 << LM.toString() << CS.toString() 1526 << getSpecifierRange(startSpecifier, specifierLen) 1527 << FixItHint::CreateRemoval(getSpecifierRange(LM.getStart(), 1528 LM.getLength())); 1529 1530 // Are we using '%n'? 1531 if (CS.getKind() == ConversionSpecifier::nArg) { 1532 // Issue a warning about this being a possible security issue. 1533 S.Diag(getLocationOfByte(CS.getStart()), diag::warn_printf_write_back) 1534 << getSpecifierRange(startSpecifier, specifierLen); 1535 // Continue checking the other format specifiers. 1536 return true; 1537 } 1538 1539 // The remaining checks depend on the data arguments. 1540 if (HasVAListArg) 1541 return true; 1542 1543 if (argIndex >= NumDataArgs) { 1544 if (FS.usesPositionalArg()) { 1545 S.Diag(getLocationOfByte(CS.getStart()), 1546 diag::warn_printf_positional_arg_exceeds_data_args) 1547 << (argIndex+1) << NumDataArgs 1548 << getSpecifierRange(startSpecifier, specifierLen); 1549 } 1550 else { 1551 S.Diag(getLocationOfByte(CS.getStart()), 1552 diag::warn_printf_insufficient_data_args) 1553 << getSpecifierRange(startSpecifier, specifierLen); 1554 } 1555 1556 // Don't do any more checking. 1557 return false; 1558 } 1559 1560 // Now type check the data expression that matches the 1561 // format specifier. 1562 const Expr *Ex = getDataArg(argIndex); 1563 const analyze_printf::ArgTypeResult &ATR = FS.getArgType(S.Context); 1564 if (ATR.isValid() && !ATR.matchesType(S.Context, Ex->getType())) { 1565 // Check if we didn't match because of an implicit cast from a 'char' 1566 // or 'short' to an 'int'. This is done because printf is a varargs 1567 // function. 1568 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Ex)) 1569 if (ICE->getType() == S.Context.IntTy) 1570 if (ATR.matchesType(S.Context, ICE->getSubExpr()->getType())) 1571 return true; 1572 1573 // We may be able to offer a FixItHint if it is a supported type. 1574 PrintfSpecifier fixedFS = FS; 1575 bool success = fixedFS.fixType(Ex->getType()); 1576 1577 if (success) { 1578 // Get the fix string from the fixed format specifier 1579 llvm::SmallString<128> buf; 1580 llvm::raw_svector_ostream os(buf); 1581 fixedFS.toString(os); 1582 1583 S.Diag(getLocationOfByte(CS.getStart()), 1584 diag::warn_printf_conversion_argument_type_mismatch) 1585 << ATR.getRepresentativeType(S.Context) << Ex->getType() 1586 << getSpecifierRange(startSpecifier, specifierLen) 1587 << Ex->getSourceRange() 1588 << FixItHint::CreateReplacement( 1589 getSpecifierRange(startSpecifier, specifierLen), 1590 os.str()); 1591 } 1592 else { 1593 S.Diag(getLocationOfByte(CS.getStart()), 1594 diag::warn_printf_conversion_argument_type_mismatch) 1595 << ATR.getRepresentativeType(S.Context) << Ex->getType() 1596 << getSpecifierRange(startSpecifier, specifierLen) 1597 << Ex->getSourceRange(); 1598 } 1599 } 1600 1601 return true; 1602} 1603 1604//===--- CHECK: Scanf format string checking ------------------------------===// 1605 1606namespace { 1607class CheckScanfHandler : public CheckFormatHandler { 1608public: 1609 CheckScanfHandler(Sema &s, const StringLiteral *fexpr, 1610 const Expr *origFormatExpr, unsigned firstDataArg, 1611 unsigned numDataArgs, bool isObjCLiteral, 1612 const char *beg, bool hasVAListArg, 1613 const CallExpr *theCall, unsigned formatIdx) 1614 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg, 1615 numDataArgs, isObjCLiteral, beg, hasVAListArg, 1616 theCall, formatIdx) {} 1617 1618 bool HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier &FS, 1619 const char *startSpecifier, 1620 unsigned specifierLen); 1621 1622 bool HandleInvalidScanfConversionSpecifier( 1623 const analyze_scanf::ScanfSpecifier &FS, 1624 const char *startSpecifier, 1625 unsigned specifierLen); 1626 1627 void HandleIncompleteScanList(const char *start, const char *end); 1628}; 1629} 1630 1631void CheckScanfHandler::HandleIncompleteScanList(const char *start, 1632 const char *end) { 1633 S.Diag(getLocationOfByte(end), diag::warn_scanf_scanlist_incomplete) 1634 << getSpecifierRange(start, end - start); 1635} 1636 1637bool CheckScanfHandler::HandleInvalidScanfConversionSpecifier( 1638 const analyze_scanf::ScanfSpecifier &FS, 1639 const char *startSpecifier, 1640 unsigned specifierLen) { 1641 1642 const analyze_scanf::ScanfConversionSpecifier &CS = 1643 FS.getConversionSpecifier(); 1644 1645 return HandleInvalidConversionSpecifier(FS.getArgIndex(), 1646 getLocationOfByte(CS.getStart()), 1647 startSpecifier, specifierLen, 1648 CS.getStart(), CS.getLength()); 1649} 1650 1651bool CheckScanfHandler::HandleScanfSpecifier( 1652 const analyze_scanf::ScanfSpecifier &FS, 1653 const char *startSpecifier, 1654 unsigned specifierLen) { 1655 1656 using namespace analyze_scanf; 1657 using namespace analyze_format_string; 1658 1659 const ScanfConversionSpecifier &CS = FS.getConversionSpecifier(); 1660 1661 // Handle case where '%' and '*' don't consume an argument. These shouldn't 1662 // be used to decide if we are using positional arguments consistently. 1663 if (FS.consumesDataArgument()) { 1664 if (atFirstArg) { 1665 atFirstArg = false; 1666 usesPositionalArgs = FS.usesPositionalArg(); 1667 } 1668 else if (usesPositionalArgs != FS.usesPositionalArg()) { 1669 // Cannot mix-and-match positional and non-positional arguments. 1670 S.Diag(getLocationOfByte(CS.getStart()), 1671 diag::warn_format_mix_positional_nonpositional_args) 1672 << getSpecifierRange(startSpecifier, specifierLen); 1673 return false; 1674 } 1675 } 1676 1677 // Check if the field with is non-zero. 1678 const OptionalAmount &Amt = FS.getFieldWidth(); 1679 if (Amt.getHowSpecified() == OptionalAmount::Constant) { 1680 if (Amt.getConstantAmount() == 0) { 1681 const CharSourceRange &R = getSpecifierRange(Amt.getStart(), 1682 Amt.getConstantLength()); 1683 S.Diag(getLocationOfByte(Amt.getStart()), 1684 diag::warn_scanf_nonzero_width) 1685 << R << FixItHint::CreateRemoval(R); 1686 } 1687 } 1688 1689 if (!FS.consumesDataArgument()) { 1690 // FIXME: Technically specifying a precision or field width here 1691 // makes no sense. Worth issuing a warning at some point. 1692 return true; 1693 } 1694 1695 // Consume the argument. 1696 unsigned argIndex = FS.getArgIndex(); 1697 if (argIndex < NumDataArgs) { 1698 // The check to see if the argIndex is valid will come later. 1699 // We set the bit here because we may exit early from this 1700 // function if we encounter some other error. 1701 CoveredArgs.set(argIndex); 1702 } 1703 1704 // FIXME: Check that the length modifier is valid with the given 1705 // conversion specifier. 1706 1707 // The remaining checks depend on the data arguments. 1708 if (HasVAListArg) 1709 return true; 1710 1711 if (argIndex >= NumDataArgs) { 1712 if (FS.usesPositionalArg()) { 1713 S.Diag(getLocationOfByte(CS.getStart()), 1714 diag::warn_printf_positional_arg_exceeds_data_args) 1715 << (argIndex+1) << NumDataArgs 1716 << getSpecifierRange(startSpecifier, specifierLen); 1717 } 1718 else { 1719 S.Diag(getLocationOfByte(CS.getStart()), 1720 diag::warn_printf_insufficient_data_args) 1721 << getSpecifierRange(startSpecifier, specifierLen); 1722 } 1723 1724 // Don't do any more checking. 1725 return false; 1726 } 1727 1728 // FIXME: Check that the argument type matches the format specifier. 1729 1730 return true; 1731} 1732 1733void Sema::CheckFormatString(const StringLiteral *FExpr, 1734 const Expr *OrigFormatExpr, 1735 const CallExpr *TheCall, bool HasVAListArg, 1736 unsigned format_idx, unsigned firstDataArg, 1737 bool isPrintf) { 1738 1739 // CHECK: is the format string a wide literal? 1740 if (FExpr->isWide()) { 1741 Diag(FExpr->getLocStart(), 1742 diag::warn_format_string_is_wide_literal) 1743 << OrigFormatExpr->getSourceRange(); 1744 return; 1745 } 1746 1747 // Str - The format string. NOTE: this is NOT null-terminated! 1748 const char *Str = FExpr->getStrData(); 1749 1750 // CHECK: empty format string? 1751 unsigned StrLen = FExpr->getByteLength(); 1752 1753 if (StrLen == 0) { 1754 Diag(FExpr->getLocStart(), diag::warn_empty_format_string) 1755 << OrigFormatExpr->getSourceRange(); 1756 return; 1757 } 1758 1759 if (isPrintf) { 1760 CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg, 1761 TheCall->getNumArgs() - firstDataArg, 1762 isa<ObjCStringLiteral>(OrigFormatExpr), Str, 1763 HasVAListArg, TheCall, format_idx); 1764 1765 if (!analyze_format_string::ParsePrintfString(H, Str, Str + StrLen)) 1766 H.DoneProcessing(); 1767 } 1768 else { 1769 CheckScanfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg, 1770 TheCall->getNumArgs() - firstDataArg, 1771 isa<ObjCStringLiteral>(OrigFormatExpr), Str, 1772 HasVAListArg, TheCall, format_idx); 1773 1774 if (!analyze_format_string::ParseScanfString(H, Str, Str + StrLen)) 1775 H.DoneProcessing(); 1776 } 1777} 1778 1779//===--- CHECK: Return Address of Stack Variable --------------------------===// 1780 1781static DeclRefExpr* EvalVal(Expr *E); 1782static DeclRefExpr* EvalAddr(Expr* E); 1783 1784/// CheckReturnStackAddr - Check if a return statement returns the address 1785/// of a stack variable. 1786void 1787Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType, 1788 SourceLocation ReturnLoc) { 1789 1790 // Perform checking for returned stack addresses. 1791 if (lhsType->isPointerType() || lhsType->isBlockPointerType()) { 1792 if (DeclRefExpr *DR = EvalAddr(RetValExp)) 1793 Diag(DR->getLocStart(), diag::warn_ret_stack_addr) 1794 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange(); 1795 1796 // Skip over implicit cast expressions when checking for block expressions. 1797 RetValExp = RetValExp->IgnoreParenCasts(); 1798 1799 if (BlockExpr *C = dyn_cast<BlockExpr>(RetValExp)) 1800 if (C->hasBlockDeclRefExprs()) 1801 Diag(C->getLocStart(), diag::err_ret_local_block) 1802 << C->getSourceRange(); 1803 1804 if (AddrLabelExpr *ALE = dyn_cast<AddrLabelExpr>(RetValExp)) 1805 Diag(ALE->getLocStart(), diag::warn_ret_addr_label) 1806 << ALE->getSourceRange(); 1807 1808 } else if (lhsType->isReferenceType()) { 1809 // Perform checking for stack values returned by reference. 1810 // Check for a reference to the stack 1811 if (DeclRefExpr *DR = EvalVal(RetValExp)) 1812 Diag(DR->getLocStart(), diag::warn_ret_stack_ref) 1813 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange(); 1814 } 1815} 1816 1817/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that 1818/// check if the expression in a return statement evaluates to an address 1819/// to a location on the stack. The recursion is used to traverse the 1820/// AST of the return expression, with recursion backtracking when we 1821/// encounter a subexpression that (1) clearly does not lead to the address 1822/// of a stack variable or (2) is something we cannot determine leads to 1823/// the address of a stack variable based on such local checking. 1824/// 1825/// EvalAddr processes expressions that are pointers that are used as 1826/// references (and not L-values). EvalVal handles all other values. 1827/// At the base case of the recursion is a check for a DeclRefExpr* in 1828/// the refers to a stack variable. 1829/// 1830/// This implementation handles: 1831/// 1832/// * pointer-to-pointer casts 1833/// * implicit conversions from array references to pointers 1834/// * taking the address of fields 1835/// * arbitrary interplay between "&" and "*" operators 1836/// * pointer arithmetic from an address of a stack variable 1837/// * taking the address of an array element where the array is on the stack 1838static DeclRefExpr* EvalAddr(Expr *E) { 1839 // We should only be called for evaluating pointer expressions. 1840 assert((E->getType()->isAnyPointerType() || 1841 E->getType()->isBlockPointerType() || 1842 E->getType()->isObjCQualifiedIdType()) && 1843 "EvalAddr only works on pointers"); 1844 1845 // Our "symbolic interpreter" is just a dispatch off the currently 1846 // viewed AST node. We then recursively traverse the AST by calling 1847 // EvalAddr and EvalVal appropriately. 1848 switch (E->getStmtClass()) { 1849 case Stmt::ParenExprClass: 1850 // Ignore parentheses. 1851 return EvalAddr(cast<ParenExpr>(E)->getSubExpr()); 1852 1853 case Stmt::UnaryOperatorClass: { 1854 // The only unary operator that make sense to handle here 1855 // is AddrOf. All others don't make sense as pointers. 1856 UnaryOperator *U = cast<UnaryOperator>(E); 1857 1858 if (U->getOpcode() == UnaryOperator::AddrOf) 1859 return EvalVal(U->getSubExpr()); 1860 else 1861 return NULL; 1862 } 1863 1864 case Stmt::BinaryOperatorClass: { 1865 // Handle pointer arithmetic. All other binary operators are not valid 1866 // in this context. 1867 BinaryOperator *B = cast<BinaryOperator>(E); 1868 BinaryOperator::Opcode op = B->getOpcode(); 1869 1870 if (op != BinaryOperator::Add && op != BinaryOperator::Sub) 1871 return NULL; 1872 1873 Expr *Base = B->getLHS(); 1874 1875 // Determine which argument is the real pointer base. It could be 1876 // the RHS argument instead of the LHS. 1877 if (!Base->getType()->isPointerType()) Base = B->getRHS(); 1878 1879 assert (Base->getType()->isPointerType()); 1880 return EvalAddr(Base); 1881 } 1882 1883 // For conditional operators we need to see if either the LHS or RHS are 1884 // valid DeclRefExpr*s. If one of them is valid, we return it. 1885 case Stmt::ConditionalOperatorClass: { 1886 ConditionalOperator *C = cast<ConditionalOperator>(E); 1887 1888 // Handle the GNU extension for missing LHS. 1889 if (Expr *lhsExpr = C->getLHS()) 1890 if (DeclRefExpr* LHS = EvalAddr(lhsExpr)) 1891 return LHS; 1892 1893 return EvalAddr(C->getRHS()); 1894 } 1895 1896 // For casts, we need to handle conversions from arrays to 1897 // pointer values, and pointer-to-pointer conversions. 1898 case Stmt::ImplicitCastExprClass: 1899 case Stmt::CStyleCastExprClass: 1900 case Stmt::CXXFunctionalCastExprClass: { 1901 Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1902 QualType T = SubExpr->getType(); 1903 1904 if (SubExpr->getType()->isPointerType() || 1905 SubExpr->getType()->isBlockPointerType() || 1906 SubExpr->getType()->isObjCQualifiedIdType()) 1907 return EvalAddr(SubExpr); 1908 else if (T->isArrayType()) 1909 return EvalVal(SubExpr); 1910 else 1911 return 0; 1912 } 1913 1914 // C++ casts. For dynamic casts, static casts, and const casts, we 1915 // are always converting from a pointer-to-pointer, so we just blow 1916 // through the cast. In the case the dynamic cast doesn't fail (and 1917 // return NULL), we take the conservative route and report cases 1918 // where we return the address of a stack variable. For Reinterpre 1919 // FIXME: The comment about is wrong; we're not always converting 1920 // from pointer to pointer. I'm guessing that this code should also 1921 // handle references to objects. 1922 case Stmt::CXXStaticCastExprClass: 1923 case Stmt::CXXDynamicCastExprClass: 1924 case Stmt::CXXConstCastExprClass: 1925 case Stmt::CXXReinterpretCastExprClass: { 1926 Expr *S = cast<CXXNamedCastExpr>(E)->getSubExpr(); 1927 if (S->getType()->isPointerType() || S->getType()->isBlockPointerType()) 1928 return EvalAddr(S); 1929 else 1930 return NULL; 1931 } 1932 1933 // Everything else: we simply don't reason about them. 1934 default: 1935 return NULL; 1936 } 1937} 1938 1939 1940/// EvalVal - This function is complements EvalAddr in the mutual recursion. 1941/// See the comments for EvalAddr for more details. 1942static DeclRefExpr* EvalVal(Expr *E) { 1943 1944 // We should only be called for evaluating non-pointer expressions, or 1945 // expressions with a pointer type that are not used as references but instead 1946 // are l-values (e.g., DeclRefExpr with a pointer type). 1947 1948 // Our "symbolic interpreter" is just a dispatch off the currently 1949 // viewed AST node. We then recursively traverse the AST by calling 1950 // EvalAddr and EvalVal appropriately. 1951 switch (E->getStmtClass()) { 1952 case Stmt::DeclRefExprClass: { 1953 // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking 1954 // at code that refers to a variable's name. We check if it has local 1955 // storage within the function, and if so, return the expression. 1956 DeclRefExpr *DR = cast<DeclRefExpr>(E); 1957 1958 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) 1959 if (V->hasLocalStorage() && !V->getType()->isReferenceType()) return DR; 1960 1961 return NULL; 1962 } 1963 1964 case Stmt::ParenExprClass: 1965 // Ignore parentheses. 1966 return EvalVal(cast<ParenExpr>(E)->getSubExpr()); 1967 1968 case Stmt::UnaryOperatorClass: { 1969 // The only unary operator that make sense to handle here 1970 // is Deref. All others don't resolve to a "name." This includes 1971 // handling all sorts of rvalues passed to a unary operator. 1972 UnaryOperator *U = cast<UnaryOperator>(E); 1973 1974 if (U->getOpcode() == UnaryOperator::Deref) 1975 return EvalAddr(U->getSubExpr()); 1976 1977 return NULL; 1978 } 1979 1980 case Stmt::ArraySubscriptExprClass: { 1981 // Array subscripts are potential references to data on the stack. We 1982 // retrieve the DeclRefExpr* for the array variable if it indeed 1983 // has local storage. 1984 return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase()); 1985 } 1986 1987 case Stmt::ConditionalOperatorClass: { 1988 // For conditional operators we need to see if either the LHS or RHS are 1989 // non-NULL DeclRefExpr's. If one is non-NULL, we return it. 1990 ConditionalOperator *C = cast<ConditionalOperator>(E); 1991 1992 // Handle the GNU extension for missing LHS. 1993 if (Expr *lhsExpr = C->getLHS()) 1994 if (DeclRefExpr *LHS = EvalVal(lhsExpr)) 1995 return LHS; 1996 1997 return EvalVal(C->getRHS()); 1998 } 1999 2000 // Accesses to members are potential references to data on the stack. 2001 case Stmt::MemberExprClass: { 2002 MemberExpr *M = cast<MemberExpr>(E); 2003 2004 // Check for indirect access. We only want direct field accesses. 2005 if (!M->isArrow()) 2006 return EvalVal(M->getBase()); 2007 else 2008 return NULL; 2009 } 2010 2011 // Everything else: we simply don't reason about them. 2012 default: 2013 return NULL; 2014 } 2015} 2016 2017//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===// 2018 2019/// Check for comparisons of floating point operands using != and ==. 2020/// Issue a warning if these are no self-comparisons, as they are not likely 2021/// to do what the programmer intended. 2022void Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) { 2023 bool EmitWarning = true; 2024 2025 Expr* LeftExprSansParen = lex->IgnoreParens(); 2026 Expr* RightExprSansParen = rex->IgnoreParens(); 2027 2028 // Special case: check for x == x (which is OK). 2029 // Do not emit warnings for such cases. 2030 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen)) 2031 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen)) 2032 if (DRL->getDecl() == DRR->getDecl()) 2033 EmitWarning = false; 2034 2035 2036 // Special case: check for comparisons against literals that can be exactly 2037 // represented by APFloat. In such cases, do not emit a warning. This 2038 // is a heuristic: often comparison against such literals are used to 2039 // detect if a value in a variable has not changed. This clearly can 2040 // lead to false negatives. 2041 if (EmitWarning) { 2042 if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) { 2043 if (FLL->isExact()) 2044 EmitWarning = false; 2045 } else 2046 if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){ 2047 if (FLR->isExact()) 2048 EmitWarning = false; 2049 } 2050 } 2051 2052 // Check for comparisons with builtin types. 2053 if (EmitWarning) 2054 if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen)) 2055 if (CL->isBuiltinCall(Context)) 2056 EmitWarning = false; 2057 2058 if (EmitWarning) 2059 if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen)) 2060 if (CR->isBuiltinCall(Context)) 2061 EmitWarning = false; 2062 2063 // Emit the diagnostic. 2064 if (EmitWarning) 2065 Diag(loc, diag::warn_floatingpoint_eq) 2066 << lex->getSourceRange() << rex->getSourceRange(); 2067} 2068 2069//===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===// 2070//===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===// 2071 2072namespace { 2073 2074/// Structure recording the 'active' range of an integer-valued 2075/// expression. 2076struct IntRange { 2077 /// The number of bits active in the int. 2078 unsigned Width; 2079 2080 /// True if the int is known not to have negative values. 2081 bool NonNegative; 2082 2083 IntRange() {} 2084 IntRange(unsigned Width, bool NonNegative) 2085 : Width(Width), NonNegative(NonNegative) 2086 {} 2087 2088 // Returns the range of the bool type. 2089 static IntRange forBoolType() { 2090 return IntRange(1, true); 2091 } 2092 2093 // Returns the range of an integral type. 2094 static IntRange forType(ASTContext &C, QualType T) { 2095 return forCanonicalType(C, T->getCanonicalTypeInternal().getTypePtr()); 2096 } 2097 2098 // Returns the range of an integeral type based on its canonical 2099 // representation. 2100 static IntRange forCanonicalType(ASTContext &C, const Type *T) { 2101 assert(T->isCanonicalUnqualified()); 2102 2103 if (const VectorType *VT = dyn_cast<VectorType>(T)) 2104 T = VT->getElementType().getTypePtr(); 2105 if (const ComplexType *CT = dyn_cast<ComplexType>(T)) 2106 T = CT->getElementType().getTypePtr(); 2107 2108 if (const EnumType *ET = dyn_cast<EnumType>(T)) { 2109 EnumDecl *Enum = ET->getDecl(); 2110 unsigned NumPositive = Enum->getNumPositiveBits(); 2111 unsigned NumNegative = Enum->getNumNegativeBits(); 2112 2113 return IntRange(std::max(NumPositive, NumNegative), NumNegative == 0); 2114 } 2115 2116 const BuiltinType *BT = cast<BuiltinType>(T); 2117 assert(BT->isInteger()); 2118 2119 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger()); 2120 } 2121 2122 // Returns the supremum of two ranges: i.e. their conservative merge. 2123 static IntRange join(IntRange L, IntRange R) { 2124 return IntRange(std::max(L.Width, R.Width), 2125 L.NonNegative && R.NonNegative); 2126 } 2127 2128 // Returns the infinum of two ranges: i.e. their aggressive merge. 2129 static IntRange meet(IntRange L, IntRange R) { 2130 return IntRange(std::min(L.Width, R.Width), 2131 L.NonNegative || R.NonNegative); 2132 } 2133}; 2134 2135IntRange GetValueRange(ASTContext &C, llvm::APSInt &value, unsigned MaxWidth) { 2136 if (value.isSigned() && value.isNegative()) 2137 return IntRange(value.getMinSignedBits(), false); 2138 2139 if (value.getBitWidth() > MaxWidth) 2140 value.trunc(MaxWidth); 2141 2142 // isNonNegative() just checks the sign bit without considering 2143 // signedness. 2144 return IntRange(value.getActiveBits(), true); 2145} 2146 2147IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty, 2148 unsigned MaxWidth) { 2149 if (result.isInt()) 2150 return GetValueRange(C, result.getInt(), MaxWidth); 2151 2152 if (result.isVector()) { 2153 IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth); 2154 for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) { 2155 IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth); 2156 R = IntRange::join(R, El); 2157 } 2158 return R; 2159 } 2160 2161 if (result.isComplexInt()) { 2162 IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth); 2163 IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth); 2164 return IntRange::join(R, I); 2165 } 2166 2167 // This can happen with lossless casts to intptr_t of "based" lvalues. 2168 // Assume it might use arbitrary bits. 2169 // FIXME: The only reason we need to pass the type in here is to get 2170 // the sign right on this one case. It would be nice if APValue 2171 // preserved this. 2172 assert(result.isLValue()); 2173 return IntRange(MaxWidth, Ty->isUnsignedIntegerType()); 2174} 2175 2176/// Pseudo-evaluate the given integer expression, estimating the 2177/// range of values it might take. 2178/// 2179/// \param MaxWidth - the width to which the value will be truncated 2180IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) { 2181 E = E->IgnoreParens(); 2182 2183 // Try a full evaluation first. 2184 Expr::EvalResult result; 2185 if (E->Evaluate(result, C)) 2186 return GetValueRange(C, result.Val, E->getType(), MaxWidth); 2187 2188 // I think we only want to look through implicit casts here; if the 2189 // user has an explicit widening cast, we should treat the value as 2190 // being of the new, wider type. 2191 if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) { 2192 if (CE->getCastKind() == CastExpr::CK_NoOp) 2193 return GetExprRange(C, CE->getSubExpr(), MaxWidth); 2194 2195 IntRange OutputTypeRange = IntRange::forType(C, CE->getType()); 2196 2197 bool isIntegerCast = (CE->getCastKind() == CastExpr::CK_IntegralCast); 2198 if (!isIntegerCast && CE->getCastKind() == CastExpr::CK_Unknown) 2199 isIntegerCast = CE->getSubExpr()->getType()->isIntegerType(); 2200 2201 // Assume that non-integer casts can span the full range of the type. 2202 if (!isIntegerCast) 2203 return OutputTypeRange; 2204 2205 IntRange SubRange 2206 = GetExprRange(C, CE->getSubExpr(), 2207 std::min(MaxWidth, OutputTypeRange.Width)); 2208 2209 // Bail out if the subexpr's range is as wide as the cast type. 2210 if (SubRange.Width >= OutputTypeRange.Width) 2211 return OutputTypeRange; 2212 2213 // Otherwise, we take the smaller width, and we're non-negative if 2214 // either the output type or the subexpr is. 2215 return IntRange(SubRange.Width, 2216 SubRange.NonNegative || OutputTypeRange.NonNegative); 2217 } 2218 2219 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { 2220 // If we can fold the condition, just take that operand. 2221 bool CondResult; 2222 if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C)) 2223 return GetExprRange(C, CondResult ? CO->getTrueExpr() 2224 : CO->getFalseExpr(), 2225 MaxWidth); 2226 2227 // Otherwise, conservatively merge. 2228 IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth); 2229 IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth); 2230 return IntRange::join(L, R); 2231 } 2232 2233 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 2234 switch (BO->getOpcode()) { 2235 2236 // Boolean-valued operations are single-bit and positive. 2237 case BinaryOperator::LAnd: 2238 case BinaryOperator::LOr: 2239 case BinaryOperator::LT: 2240 case BinaryOperator::GT: 2241 case BinaryOperator::LE: 2242 case BinaryOperator::GE: 2243 case BinaryOperator::EQ: 2244 case BinaryOperator::NE: 2245 return IntRange::forBoolType(); 2246 2247 // The type of these compound assignments is the type of the LHS, 2248 // so the RHS is not necessarily an integer. 2249 case BinaryOperator::MulAssign: 2250 case BinaryOperator::DivAssign: 2251 case BinaryOperator::RemAssign: 2252 case BinaryOperator::AddAssign: 2253 case BinaryOperator::SubAssign: 2254 return IntRange::forType(C, E->getType()); 2255 2256 // Operations with opaque sources are black-listed. 2257 case BinaryOperator::PtrMemD: 2258 case BinaryOperator::PtrMemI: 2259 return IntRange::forType(C, E->getType()); 2260 2261 // Bitwise-and uses the *infinum* of the two source ranges. 2262 case BinaryOperator::And: 2263 case BinaryOperator::AndAssign: 2264 return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth), 2265 GetExprRange(C, BO->getRHS(), MaxWidth)); 2266 2267 // Left shift gets black-listed based on a judgement call. 2268 case BinaryOperator::Shl: 2269 // ...except that we want to treat '1 << (blah)' as logically 2270 // positive. It's an important idiom. 2271 if (IntegerLiteral *I 2272 = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) { 2273 if (I->getValue() == 1) { 2274 IntRange R = IntRange::forType(C, E->getType()); 2275 return IntRange(R.Width, /*NonNegative*/ true); 2276 } 2277 } 2278 // fallthrough 2279 2280 case BinaryOperator::ShlAssign: 2281 return IntRange::forType(C, E->getType()); 2282 2283 // Right shift by a constant can narrow its left argument. 2284 case BinaryOperator::Shr: 2285 case BinaryOperator::ShrAssign: { 2286 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth); 2287 2288 // If the shift amount is a positive constant, drop the width by 2289 // that much. 2290 llvm::APSInt shift; 2291 if (BO->getRHS()->isIntegerConstantExpr(shift, C) && 2292 shift.isNonNegative()) { 2293 unsigned zext = shift.getZExtValue(); 2294 if (zext >= L.Width) 2295 L.Width = (L.NonNegative ? 0 : 1); 2296 else 2297 L.Width -= zext; 2298 } 2299 2300 return L; 2301 } 2302 2303 // Comma acts as its right operand. 2304 case BinaryOperator::Comma: 2305 return GetExprRange(C, BO->getRHS(), MaxWidth); 2306 2307 // Black-list pointer subtractions. 2308 case BinaryOperator::Sub: 2309 if (BO->getLHS()->getType()->isPointerType()) 2310 return IntRange::forType(C, E->getType()); 2311 // fallthrough 2312 2313 default: 2314 break; 2315 } 2316 2317 // Treat every other operator as if it were closed on the 2318 // narrowest type that encompasses both operands. 2319 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth); 2320 IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth); 2321 return IntRange::join(L, R); 2322 } 2323 2324 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) { 2325 switch (UO->getOpcode()) { 2326 // Boolean-valued operations are white-listed. 2327 case UnaryOperator::LNot: 2328 return IntRange::forBoolType(); 2329 2330 // Operations with opaque sources are black-listed. 2331 case UnaryOperator::Deref: 2332 case UnaryOperator::AddrOf: // should be impossible 2333 case UnaryOperator::OffsetOf: 2334 return IntRange::forType(C, E->getType()); 2335 2336 default: 2337 return GetExprRange(C, UO->getSubExpr(), MaxWidth); 2338 } 2339 } 2340 2341 if (dyn_cast<OffsetOfExpr>(E)) { 2342 IntRange::forType(C, E->getType()); 2343 } 2344 2345 FieldDecl *BitField = E->getBitField(); 2346 if (BitField) { 2347 llvm::APSInt BitWidthAP = BitField->getBitWidth()->EvaluateAsInt(C); 2348 unsigned BitWidth = BitWidthAP.getZExtValue(); 2349 2350 return IntRange(BitWidth, BitField->getType()->isUnsignedIntegerType()); 2351 } 2352 2353 return IntRange::forType(C, E->getType()); 2354} 2355 2356IntRange GetExprRange(ASTContext &C, Expr *E) { 2357 return GetExprRange(C, E, C.getIntWidth(E->getType())); 2358} 2359 2360/// Checks whether the given value, which currently has the given 2361/// source semantics, has the same value when coerced through the 2362/// target semantics. 2363bool IsSameFloatAfterCast(const llvm::APFloat &value, 2364 const llvm::fltSemantics &Src, 2365 const llvm::fltSemantics &Tgt) { 2366 llvm::APFloat truncated = value; 2367 2368 bool ignored; 2369 truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored); 2370 truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored); 2371 2372 return truncated.bitwiseIsEqual(value); 2373} 2374 2375/// Checks whether the given value, which currently has the given 2376/// source semantics, has the same value when coerced through the 2377/// target semantics. 2378/// 2379/// The value might be a vector of floats (or a complex number). 2380bool IsSameFloatAfterCast(const APValue &value, 2381 const llvm::fltSemantics &Src, 2382 const llvm::fltSemantics &Tgt) { 2383 if (value.isFloat()) 2384 return IsSameFloatAfterCast(value.getFloat(), Src, Tgt); 2385 2386 if (value.isVector()) { 2387 for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i) 2388 if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt)) 2389 return false; 2390 return true; 2391 } 2392 2393 assert(value.isComplexFloat()); 2394 return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) && 2395 IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt)); 2396} 2397 2398void AnalyzeImplicitConversions(Sema &S, Expr *E); 2399 2400bool IsZero(Sema &S, Expr *E) { 2401 llvm::APSInt Value; 2402 return E->isIntegerConstantExpr(Value, S.Context) && Value == 0; 2403} 2404 2405void CheckTrivialUnsignedComparison(Sema &S, BinaryOperator *E) { 2406 BinaryOperator::Opcode op = E->getOpcode(); 2407 if (op == BinaryOperator::LT && IsZero(S, E->getRHS())) { 2408 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison) 2409 << "< 0" << "false" 2410 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange(); 2411 } else if (op == BinaryOperator::GE && IsZero(S, E->getRHS())) { 2412 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison) 2413 << ">= 0" << "true" 2414 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange(); 2415 } else if (op == BinaryOperator::GT && IsZero(S, E->getLHS())) { 2416 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison) 2417 << "0 >" << "false" 2418 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange(); 2419 } else if (op == BinaryOperator::LE && IsZero(S, E->getLHS())) { 2420 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison) 2421 << "0 <=" << "true" 2422 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange(); 2423 } 2424} 2425 2426/// Analyze the operands of the given comparison. Implements the 2427/// fallback case from AnalyzeComparison. 2428void AnalyzeImpConvsInComparison(Sema &S, BinaryOperator *E) { 2429 AnalyzeImplicitConversions(S, E->getLHS()); 2430 AnalyzeImplicitConversions(S, E->getRHS()); 2431} 2432 2433/// \brief Implements -Wsign-compare. 2434/// 2435/// \param lex the left-hand expression 2436/// \param rex the right-hand expression 2437/// \param OpLoc the location of the joining operator 2438/// \param BinOpc binary opcode or 0 2439void AnalyzeComparison(Sema &S, BinaryOperator *E) { 2440 // The type the comparison is being performed in. 2441 QualType T = E->getLHS()->getType(); 2442 assert(S.Context.hasSameUnqualifiedType(T, E->getRHS()->getType()) 2443 && "comparison with mismatched types"); 2444 2445 // We don't do anything special if this isn't an unsigned integral 2446 // comparison: we're only interested in integral comparisons, and 2447 // signed comparisons only happen in cases we don't care to warn about. 2448 if (!T->isUnsignedIntegerType()) 2449 return AnalyzeImpConvsInComparison(S, E); 2450 2451 Expr *lex = E->getLHS()->IgnoreParenImpCasts(); 2452 Expr *rex = E->getRHS()->IgnoreParenImpCasts(); 2453 2454 // Check to see if one of the (unmodified) operands is of different 2455 // signedness. 2456 Expr *signedOperand, *unsignedOperand; 2457 if (lex->getType()->isSignedIntegerType()) { 2458 assert(!rex->getType()->isSignedIntegerType() && 2459 "unsigned comparison between two signed integer expressions?"); 2460 signedOperand = lex; 2461 unsignedOperand = rex; 2462 } else if (rex->getType()->isSignedIntegerType()) { 2463 signedOperand = rex; 2464 unsignedOperand = lex; 2465 } else { 2466 CheckTrivialUnsignedComparison(S, E); 2467 return AnalyzeImpConvsInComparison(S, E); 2468 } 2469 2470 // Otherwise, calculate the effective range of the signed operand. 2471 IntRange signedRange = GetExprRange(S.Context, signedOperand); 2472 2473 // Go ahead and analyze implicit conversions in the operands. Note 2474 // that we skip the implicit conversions on both sides. 2475 AnalyzeImplicitConversions(S, lex); 2476 AnalyzeImplicitConversions(S, rex); 2477 2478 // If the signed range is non-negative, -Wsign-compare won't fire, 2479 // but we should still check for comparisons which are always true 2480 // or false. 2481 if (signedRange.NonNegative) 2482 return CheckTrivialUnsignedComparison(S, E); 2483 2484 // For (in)equality comparisons, if the unsigned operand is a 2485 // constant which cannot collide with a overflowed signed operand, 2486 // then reinterpreting the signed operand as unsigned will not 2487 // change the result of the comparison. 2488 if (E->isEqualityOp()) { 2489 unsigned comparisonWidth = S.Context.getIntWidth(T); 2490 IntRange unsignedRange = GetExprRange(S.Context, unsignedOperand); 2491 2492 // We should never be unable to prove that the unsigned operand is 2493 // non-negative. 2494 assert(unsignedRange.NonNegative && "unsigned range includes negative?"); 2495 2496 if (unsignedRange.Width < comparisonWidth) 2497 return; 2498 } 2499 2500 S.Diag(E->getOperatorLoc(), diag::warn_mixed_sign_comparison) 2501 << lex->getType() << rex->getType() 2502 << lex->getSourceRange() << rex->getSourceRange(); 2503} 2504 2505/// Diagnose an implicit cast; purely a helper for CheckImplicitConversion. 2506void DiagnoseImpCast(Sema &S, Expr *E, QualType T, unsigned diag) { 2507 S.Diag(E->getExprLoc(), diag) << E->getType() << T << E->getSourceRange(); 2508} 2509 2510void CheckImplicitConversion(Sema &S, Expr *E, QualType T, 2511 bool *ICContext = 0) { 2512 if (E->isTypeDependent() || E->isValueDependent()) return; 2513 2514 const Type *Source = S.Context.getCanonicalType(E->getType()).getTypePtr(); 2515 const Type *Target = S.Context.getCanonicalType(T).getTypePtr(); 2516 if (Source == Target) return; 2517 if (Target->isDependentType()) return; 2518 2519 // Never diagnose implicit casts to bool. 2520 if (Target->isSpecificBuiltinType(BuiltinType::Bool)) 2521 return; 2522 2523 // Strip vector types. 2524 if (isa<VectorType>(Source)) { 2525 if (!isa<VectorType>(Target)) 2526 return DiagnoseImpCast(S, E, T, diag::warn_impcast_vector_scalar); 2527 2528 Source = cast<VectorType>(Source)->getElementType().getTypePtr(); 2529 Target = cast<VectorType>(Target)->getElementType().getTypePtr(); 2530 } 2531 2532 // Strip complex types. 2533 if (isa<ComplexType>(Source)) { 2534 if (!isa<ComplexType>(Target)) 2535 return DiagnoseImpCast(S, E, T, diag::warn_impcast_complex_scalar); 2536 2537 Source = cast<ComplexType>(Source)->getElementType().getTypePtr(); 2538 Target = cast<ComplexType>(Target)->getElementType().getTypePtr(); 2539 } 2540 2541 const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source); 2542 const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target); 2543 2544 // If the source is floating point... 2545 if (SourceBT && SourceBT->isFloatingPoint()) { 2546 // ...and the target is floating point... 2547 if (TargetBT && TargetBT->isFloatingPoint()) { 2548 // ...then warn if we're dropping FP rank. 2549 2550 // Builtin FP kinds are ordered by increasing FP rank. 2551 if (SourceBT->getKind() > TargetBT->getKind()) { 2552 // Don't warn about float constants that are precisely 2553 // representable in the target type. 2554 Expr::EvalResult result; 2555 if (E->Evaluate(result, S.Context)) { 2556 // Value might be a float, a float vector, or a float complex. 2557 if (IsSameFloatAfterCast(result.Val, 2558 S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)), 2559 S.Context.getFloatTypeSemantics(QualType(SourceBT, 0)))) 2560 return; 2561 } 2562 2563 DiagnoseImpCast(S, E, T, diag::warn_impcast_float_precision); 2564 } 2565 return; 2566 } 2567 2568 // If the target is integral, always warn. 2569 if ((TargetBT && TargetBT->isInteger())) 2570 // TODO: don't warn for integer values? 2571 DiagnoseImpCast(S, E, T, diag::warn_impcast_float_integer); 2572 2573 return; 2574 } 2575 2576 if (!Source->isIntegerType() || !Target->isIntegerType()) 2577 return; 2578 2579 IntRange SourceRange = GetExprRange(S.Context, E); 2580 IntRange TargetRange = IntRange::forCanonicalType(S.Context, Target); 2581 2582 if (SourceRange.Width > TargetRange.Width) { 2583 // People want to build with -Wshorten-64-to-32 and not -Wconversion 2584 // and by god we'll let them. 2585 if (SourceRange.Width == 64 && TargetRange.Width == 32) 2586 return DiagnoseImpCast(S, E, T, diag::warn_impcast_integer_64_32); 2587 return DiagnoseImpCast(S, E, T, diag::warn_impcast_integer_precision); 2588 } 2589 2590 if ((TargetRange.NonNegative && !SourceRange.NonNegative) || 2591 (!TargetRange.NonNegative && SourceRange.NonNegative && 2592 SourceRange.Width == TargetRange.Width)) { 2593 unsigned DiagID = diag::warn_impcast_integer_sign; 2594 2595 // Traditionally, gcc has warned about this under -Wsign-compare. 2596 // We also want to warn about it in -Wconversion. 2597 // So if -Wconversion is off, use a completely identical diagnostic 2598 // in the sign-compare group. 2599 // The conditional-checking code will 2600 if (ICContext) { 2601 DiagID = diag::warn_impcast_integer_sign_conditional; 2602 *ICContext = true; 2603 } 2604 2605 return DiagnoseImpCast(S, E, T, DiagID); 2606 } 2607 2608 return; 2609} 2610 2611void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T); 2612 2613void CheckConditionalOperand(Sema &S, Expr *E, QualType T, 2614 bool &ICContext) { 2615 E = E->IgnoreParenImpCasts(); 2616 2617 if (isa<ConditionalOperator>(E)) 2618 return CheckConditionalOperator(S, cast<ConditionalOperator>(E), T); 2619 2620 AnalyzeImplicitConversions(S, E); 2621 if (E->getType() != T) 2622 return CheckImplicitConversion(S, E, T, &ICContext); 2623 return; 2624} 2625 2626void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T) { 2627 AnalyzeImplicitConversions(S, E->getCond()); 2628 2629 bool Suspicious = false; 2630 CheckConditionalOperand(S, E->getTrueExpr(), T, Suspicious); 2631 CheckConditionalOperand(S, E->getFalseExpr(), T, Suspicious); 2632 2633 // If -Wconversion would have warned about either of the candidates 2634 // for a signedness conversion to the context type... 2635 if (!Suspicious) return; 2636 2637 // ...but it's currently ignored... 2638 if (S.Diags.getDiagnosticLevel(diag::warn_impcast_integer_sign_conditional)) 2639 return; 2640 2641 // ...and -Wsign-compare isn't... 2642 if (!S.Diags.getDiagnosticLevel(diag::warn_mixed_sign_conditional)) 2643 return; 2644 2645 // ...then check whether it would have warned about either of the 2646 // candidates for a signedness conversion to the condition type. 2647 if (E->getType() != T) { 2648 Suspicious = false; 2649 CheckImplicitConversion(S, E->getTrueExpr()->IgnoreParenImpCasts(), 2650 E->getType(), &Suspicious); 2651 if (!Suspicious) 2652 CheckImplicitConversion(S, E->getFalseExpr()->IgnoreParenImpCasts(), 2653 E->getType(), &Suspicious); 2654 if (!Suspicious) 2655 return; 2656 } 2657 2658 // If so, emit a diagnostic under -Wsign-compare. 2659 Expr *lex = E->getTrueExpr()->IgnoreParenImpCasts(); 2660 Expr *rex = E->getFalseExpr()->IgnoreParenImpCasts(); 2661 S.Diag(E->getQuestionLoc(), diag::warn_mixed_sign_conditional) 2662 << lex->getType() << rex->getType() 2663 << lex->getSourceRange() << rex->getSourceRange(); 2664} 2665 2666/// AnalyzeImplicitConversions - Find and report any interesting 2667/// implicit conversions in the given expression. There are a couple 2668/// of competing diagnostics here, -Wconversion and -Wsign-compare. 2669void AnalyzeImplicitConversions(Sema &S, Expr *OrigE) { 2670 QualType T = OrigE->getType(); 2671 Expr *E = OrigE->IgnoreParenImpCasts(); 2672 2673 // For conditional operators, we analyze the arguments as if they 2674 // were being fed directly into the output. 2675 if (isa<ConditionalOperator>(E)) { 2676 ConditionalOperator *CO = cast<ConditionalOperator>(E); 2677 CheckConditionalOperator(S, CO, T); 2678 return; 2679 } 2680 2681 // Go ahead and check any implicit conversions we might have skipped. 2682 // The non-canonical typecheck is just an optimization; 2683 // CheckImplicitConversion will filter out dead implicit conversions. 2684 if (E->getType() != T) 2685 CheckImplicitConversion(S, E, T); 2686 2687 // Now continue drilling into this expression. 2688 2689 // Skip past explicit casts. 2690 if (isa<ExplicitCastExpr>(E)) { 2691 E = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreParenImpCasts(); 2692 return AnalyzeImplicitConversions(S, E); 2693 } 2694 2695 // Do a somewhat different check with comparison operators. 2696 if (isa<BinaryOperator>(E) && cast<BinaryOperator>(E)->isComparisonOp()) 2697 return AnalyzeComparison(S, cast<BinaryOperator>(E)); 2698 2699 // These break the otherwise-useful invariant below. Fortunately, 2700 // we don't really need to recurse into them, because any internal 2701 // expressions should have been analyzed already when they were 2702 // built into statements. 2703 if (isa<StmtExpr>(E)) return; 2704 2705 // Don't descend into unevaluated contexts. 2706 if (isa<SizeOfAlignOfExpr>(E)) return; 2707 2708 // Now just recurse over the expression's children. 2709 for (Stmt::child_iterator I = E->child_begin(), IE = E->child_end(); 2710 I != IE; ++I) 2711 AnalyzeImplicitConversions(S, cast<Expr>(*I)); 2712} 2713 2714} // end anonymous namespace 2715 2716/// Diagnoses "dangerous" implicit conversions within the given 2717/// expression (which is a full expression). Implements -Wconversion 2718/// and -Wsign-compare. 2719void Sema::CheckImplicitConversions(Expr *E) { 2720 // Don't diagnose in unevaluated contexts. 2721 if (ExprEvalContexts.back().Context == Sema::Unevaluated) 2722 return; 2723 2724 // Don't diagnose for value- or type-dependent expressions. 2725 if (E->isTypeDependent() || E->isValueDependent()) 2726 return; 2727 2728 AnalyzeImplicitConversions(*this, E); 2729} 2730 2731/// CheckParmsForFunctionDef - Check that the parameters of the given 2732/// function are appropriate for the definition of a function. This 2733/// takes care of any checks that cannot be performed on the 2734/// declaration itself, e.g., that the types of each of the function 2735/// parameters are complete. 2736bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 2737 bool HasInvalidParm = false; 2738 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2739 ParmVarDecl *Param = FD->getParamDecl(p); 2740 2741 // C99 6.7.5.3p4: the parameters in a parameter type list in a 2742 // function declarator that is part of a function definition of 2743 // that function shall not have incomplete type. 2744 // 2745 // This is also C++ [dcl.fct]p6. 2746 if (!Param->isInvalidDecl() && 2747 RequireCompleteType(Param->getLocation(), Param->getType(), 2748 diag::err_typecheck_decl_incomplete_type)) { 2749 Param->setInvalidDecl(); 2750 HasInvalidParm = true; 2751 } 2752 2753 // C99 6.9.1p5: If the declarator includes a parameter type list, the 2754 // declaration of each parameter shall include an identifier. 2755 if (Param->getIdentifier() == 0 && 2756 !Param->isImplicit() && 2757 !getLangOptions().CPlusPlus) 2758 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 2759 2760 // C99 6.7.5.3p12: 2761 // If the function declarator is not part of a definition of that 2762 // function, parameters may have incomplete type and may use the [*] 2763 // notation in their sequences of declarator specifiers to specify 2764 // variable length array types. 2765 QualType PType = Param->getOriginalType(); 2766 if (const ArrayType *AT = Context.getAsArrayType(PType)) { 2767 if (AT->getSizeModifier() == ArrayType::Star) { 2768 // FIXME: This diagnosic should point the the '[*]' if source-location 2769 // information is added for it. 2770 Diag(Param->getLocation(), diag::err_array_star_in_function_definition); 2771 } 2772 } 2773 } 2774 2775 return HasInvalidParm; 2776} 2777