SemaChecking.cpp revision 75c29a012793292ff4578015a9113bf086156d7f
148486893f46d2e12e926682a3ecb908716bc66c4Chris Lattner//===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===// 2b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell// 3b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell// The LLVM Compiler Infrastructure 4b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell// 5b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell// This file is distributed under the University of Illinois Open Source 6b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell// License. See LICENSE.TXT for details. 7b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell// 8b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell//===----------------------------------------------------------------------===// 97e70829632f82de15db187845666aaca6e04b792Chris Lattner// 107e70829632f82de15db187845666aaca6e04b792Chris Lattner// This file implements extra semantic analysis beyond what is enforced 117e70829632f82de15db187845666aaca6e04b792Chris Lattner// by the C type system. 127e70829632f82de15db187845666aaca6e04b792Chris Lattner// 137e70829632f82de15db187845666aaca6e04b792Chris Lattner//===----------------------------------------------------------------------===// 147e70829632f82de15db187845666aaca6e04b792Chris Lattner 157e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Sema/Sema.h" 167e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Sema/SemaInternal.h" 177e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Sema/ScopeInfo.h" 187e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Analysis/Analyses/FormatString.h" 197e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/AST/ASTContext.h" 207e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/AST/CharUnits.h" 217e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/AST/DeclCXX.h" 22a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner#include "clang/AST/DeclObjC.h" 237e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/AST/ExprCXX.h" 247e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/AST/ExprObjC.h" 257e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/AST/DeclObjC.h" 267e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/AST/StmtCXX.h" 277e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/AST/StmtObjC.h" 287e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Lex/LiteralSupport.h" 297e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Lex/Preprocessor.h" 307e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "llvm/ADT/BitVector.h" 317e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "llvm/ADT/STLExtras.h" 327e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "llvm/Support/raw_ostream.h" 337e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Basic/TargetBuiltins.h" 347e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Basic/TargetInfo.h" 357e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Basic/ConvertUTF.h" 367e70829632f82de15db187845666aaca6e04b792Chris Lattner 377e70829632f82de15db187845666aaca6e04b792Chris Lattner#include <limits> 38a9f6e4ae0eaea69949755807b7207177f256eaceBrian Gaekeusing namespace clang; 39a9f6e4ae0eaea69949755807b7207177f256eaceBrian Gaekeusing namespace sema; 407e70829632f82de15db187845666aaca6e04b792Chris Lattner 410d219edad2fd5e7b400ecd49ac833a7a3199af60Chris Lattner/// getLocationOfStringLiteralByte - Return a source location that points to the 42803f03e217ec25cf71b2b6dea65da2e377527b6bChris Lattner/// specified byte of the specified string literal. 437e70829632f82de15db187845666aaca6e04b792Chris Lattner/// 44d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke/// Strings are amazingly complex. They can be formed from multiple tokens and 45d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke/// can have escape sequences in them in addition to the usual trigraph and 467e70829632f82de15db187845666aaca6e04b792Chris Lattner/// escaped newline business. This routine handles this complexity. 477e70829632f82de15db187845666aaca6e04b792Chris Lattner/// 487e70829632f82de15db187845666aaca6e04b792Chris LattnerSourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL, 497e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned ByteNo) const { 507e70829632f82de15db187845666aaca6e04b792Chris Lattner assert(!SL->isWide() && "This doesn't work for wide strings yet"); 517e70829632f82de15db187845666aaca6e04b792Chris Lattner 527e70829632f82de15db187845666aaca6e04b792Chris Lattner // Loop over all of the tokens in this string until we find the one that 537e70829632f82de15db187845666aaca6e04b792Chris Lattner // contains the byte we're looking for. 547e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned TokNo = 0; 557e70829632f82de15db187845666aaca6e04b792Chris Lattner while (1) { 567e70829632f82de15db187845666aaca6e04b792Chris Lattner assert(TokNo < SL->getNumConcatenated() && "Invalid byte number!"); 577e70829632f82de15db187845666aaca6e04b792Chris Lattner SourceLocation StrTokLoc = SL->getStrTokenLoc(TokNo); 587e70829632f82de15db187845666aaca6e04b792Chris Lattner 597e70829632f82de15db187845666aaca6e04b792Chris Lattner // Get the spelling of the string so that we can get the data that makes up 607e70829632f82de15db187845666aaca6e04b792Chris Lattner // the string literal, not the identifier for the macro it is potentially 617e70829632f82de15db187845666aaca6e04b792Chris Lattner // expanded through. 627e70829632f82de15db187845666aaca6e04b792Chris Lattner SourceLocation StrTokSpellingLoc = SourceMgr.getSpellingLoc(StrTokLoc); 637e70829632f82de15db187845666aaca6e04b792Chris Lattner 647e70829632f82de15db187845666aaca6e04b792Chris Lattner // Re-lex the token to get its length and original spelling. 657e70829632f82de15db187845666aaca6e04b792Chris Lattner std::pair<FileID, unsigned> LocInfo = 667e70829632f82de15db187845666aaca6e04b792Chris Lattner SourceMgr.getDecomposedLoc(StrTokSpellingLoc); 677e70829632f82de15db187845666aaca6e04b792Chris Lattner bool Invalid = false; 687e70829632f82de15db187845666aaca6e04b792Chris Lattner llvm::StringRef Buffer = SourceMgr.getBufferData(LocInfo.first, &Invalid); 697e70829632f82de15db187845666aaca6e04b792Chris Lattner if (Invalid) 707e70829632f82de15db187845666aaca6e04b792Chris Lattner return StrTokSpellingLoc; 717e70829632f82de15db187845666aaca6e04b792Chris Lattner 727e70829632f82de15db187845666aaca6e04b792Chris Lattner const char *StrData = Buffer.data()+LocInfo.second; 737e70829632f82de15db187845666aaca6e04b792Chris Lattner 747e70829632f82de15db187845666aaca6e04b792Chris Lattner // Create a langops struct and enable trigraphs. This is sufficient for 757e70829632f82de15db187845666aaca6e04b792Chris Lattner // relexing tokens. 767e70829632f82de15db187845666aaca6e04b792Chris Lattner LangOptions LangOpts; 777e70829632f82de15db187845666aaca6e04b792Chris Lattner LangOpts.Trigraphs = true; 787e70829632f82de15db187845666aaca6e04b792Chris Lattner 797e70829632f82de15db187845666aaca6e04b792Chris Lattner // Create a lexer starting at the beginning of this token. 807e70829632f82de15db187845666aaca6e04b792Chris Lattner Lexer TheLexer(StrTokSpellingLoc, LangOpts, Buffer.begin(), StrData, 81a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner Buffer.end()); 820d219edad2fd5e7b400ecd49ac833a7a3199af60Chris Lattner Token TheTok; 837e70829632f82de15db187845666aaca6e04b792Chris Lattner TheLexer.LexFromRawLexer(TheTok); 840d219edad2fd5e7b400ecd49ac833a7a3199af60Chris Lattner 85a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner // Use the StringLiteralParser to compute the length of the string in bytes. 8632862da7c7107d792d25a885f9bd2d0402ae7126Chris Lattner StringLiteralParser SLP(&TheTok, 1, PP, /*Complain=*/false); 8732862da7c7107d792d25a885f9bd2d0402ae7126Chris Lattner unsigned TokNumBytes = SLP.GetStringLength(); 88a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner 89a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner // If the byte is in this token, return the location of the byte. 9032862da7c7107d792d25a885f9bd2d0402ae7126Chris Lattner if (ByteNo < TokNumBytes || 917e70829632f82de15db187845666aaca6e04b792Chris Lattner (ByteNo == TokNumBytes && TokNo == SL->getNumConcatenated())) { 927e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned Offset = 937e70829632f82de15db187845666aaca6e04b792Chris Lattner StringLiteralParser::getOffsetOfStringByte(TheTok, ByteNo, PP, 947e70829632f82de15db187845666aaca6e04b792Chris Lattner /*Complain=*/false); 9533adbcc87d92c6c3e620870c804f4a2533ecc850Vikram S. Adve 967e70829632f82de15db187845666aaca6e04b792Chris Lattner // Now that we know the offset of the token in the spelling, use the 977e70829632f82de15db187845666aaca6e04b792Chris Lattner // preprocessor to get the offset in the original source. 987e70829632f82de15db187845666aaca6e04b792Chris Lattner return PP.AdvanceToTokenCharacter(StrTokLoc, Offset); 997e70829632f82de15db187845666aaca6e04b792Chris Lattner } 1007e70829632f82de15db187845666aaca6e04b792Chris Lattner 1017e70829632f82de15db187845666aaca6e04b792Chris Lattner // Move to the next string token. 1027e70829632f82de15db187845666aaca6e04b792Chris Lattner ++TokNo; 1037e70829632f82de15db187845666aaca6e04b792Chris Lattner ByteNo -= TokNumBytes; 1047e70829632f82de15db187845666aaca6e04b792Chris Lattner } 1057e70829632f82de15db187845666aaca6e04b792Chris Lattner} 1067e70829632f82de15db187845666aaca6e04b792Chris Lattner 1077e70829632f82de15db187845666aaca6e04b792Chris Lattner/// CheckablePrintfAttr - does a function call have a "printf" attribute 1087e70829632f82de15db187845666aaca6e04b792Chris Lattner/// and arguments that merit checking? 1097e70829632f82de15db187845666aaca6e04b792Chris Lattnerbool Sema::CheckablePrintfAttr(const FormatAttr *Format, CallExpr *TheCall) { 1107e70829632f82de15db187845666aaca6e04b792Chris Lattner if (Format->getType() == "printf") return true; 1117e70829632f82de15db187845666aaca6e04b792Chris Lattner if (Format->getType() == "printf0") { 1127e70829632f82de15db187845666aaca6e04b792Chris Lattner // printf0 allows null "format" string; if so don't check format/args 1137e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned format_idx = Format->getFormatIdx() - 1; 1147e70829632f82de15db187845666aaca6e04b792Chris Lattner // Does the index refer to the implicit object argument? 1157e70829632f82de15db187845666aaca6e04b792Chris Lattner if (isa<CXXMemberCallExpr>(TheCall)) { 1167e70829632f82de15db187845666aaca6e04b792Chris Lattner if (format_idx == 0) 1177e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 1187e70829632f82de15db187845666aaca6e04b792Chris Lattner --format_idx; 1197e70829632f82de15db187845666aaca6e04b792Chris Lattner } 1207e70829632f82de15db187845666aaca6e04b792Chris Lattner if (format_idx < TheCall->getNumArgs()) { 1217e70829632f82de15db187845666aaca6e04b792Chris Lattner Expr *Format = TheCall->getArg(format_idx)->IgnoreParenCasts(); 1227e70829632f82de15db187845666aaca6e04b792Chris Lattner if (!Format->isNullPointerConstant(Context, 1237e70829632f82de15db187845666aaca6e04b792Chris Lattner Expr::NPC_ValueDependentIsNull)) 1247e70829632f82de15db187845666aaca6e04b792Chris Lattner return true; 1257e70829632f82de15db187845666aaca6e04b792Chris Lattner } 1267e70829632f82de15db187845666aaca6e04b792Chris Lattner } 1277e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 1287e70829632f82de15db187845666aaca6e04b792Chris Lattner} 1297e70829632f82de15db187845666aaca6e04b792Chris Lattner 1307e70829632f82de15db187845666aaca6e04b792Chris LattnerExprResult 1317e70829632f82de15db187845666aaca6e04b792Chris LattnerSema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) { 1327e70829632f82de15db187845666aaca6e04b792Chris Lattner ExprResult TheCallResult(Owned(TheCall)); 1337e70829632f82de15db187845666aaca6e04b792Chris Lattner 1347e70829632f82de15db187845666aaca6e04b792Chris Lattner // Find out if any arguments are required to be integer constant expressions. 1357e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned ICEArguments = 0; 1367e70829632f82de15db187845666aaca6e04b792Chris Lattner ASTContext::GetBuiltinTypeError Error; 1377e70829632f82de15db187845666aaca6e04b792Chris Lattner Context.GetBuiltinType(BuiltinID, Error, &ICEArguments); 1387e70829632f82de15db187845666aaca6e04b792Chris Lattner if (Error != ASTContext::GE_None) 1397e70829632f82de15db187845666aaca6e04b792Chris Lattner ICEArguments = 0; // Don't diagnose previously diagnosed errors. 1407e70829632f82de15db187845666aaca6e04b792Chris Lattner 1417e70829632f82de15db187845666aaca6e04b792Chris Lattner // If any arguments are required to be ICE's, check and diagnose. 1427e70829632f82de15db187845666aaca6e04b792Chris Lattner for (unsigned ArgNo = 0; ICEArguments != 0; ++ArgNo) { 1437e70829632f82de15db187845666aaca6e04b792Chris Lattner // Skip arguments not required to be ICE's. 1447e70829632f82de15db187845666aaca6e04b792Chris Lattner if ((ICEArguments & (1 << ArgNo)) == 0) continue; 1457e70829632f82de15db187845666aaca6e04b792Chris Lattner 1467e70829632f82de15db187845666aaca6e04b792Chris Lattner llvm::APSInt Result; 1477e70829632f82de15db187845666aaca6e04b792Chris Lattner if (SemaBuiltinConstantArg(TheCall, ArgNo, Result)) 1487e70829632f82de15db187845666aaca6e04b792Chris Lattner return true; 1497e70829632f82de15db187845666aaca6e04b792Chris Lattner ICEArguments &= ~(1 << ArgNo); 1507e70829632f82de15db187845666aaca6e04b792Chris Lattner } 1517e70829632f82de15db187845666aaca6e04b792Chris Lattner 1527e70829632f82de15db187845666aaca6e04b792Chris Lattner switch (BuiltinID) { 1537e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__builtin___CFStringMakeConstantString: 1547e70829632f82de15db187845666aaca6e04b792Chris Lattner assert(TheCall->getNumArgs() == 1 && 1552cca3008e86aa5448a629c744064daecb531bf94Chris Lattner "Wrong # arguments to builtin CFStringMakeConstantString"); 1562cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (CheckObjCString(TheCall->getArg(0))) 1572cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return ExprError(); 1582cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 15971be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos case Builtin::BI__builtin_stdarg_start: 16071be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos case Builtin::BI__builtin_va_start: 16171be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos if (SemaBuiltinVAStart(TheCall)) 16271be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos return ExprError(); 16371be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos break; 16471be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos case Builtin::BI__builtin_isgreater: 16571be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos case Builtin::BI__builtin_isgreaterequal: 16671be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos case Builtin::BI__builtin_isless: 16771be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos case Builtin::BI__builtin_islessequal: 16871be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos case Builtin::BI__builtin_islessgreater: 16971be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos case Builtin::BI__builtin_isunordered: 17071be6db3efd233ae7eafe3e23ad9d9ac70bf0706Alkis Evlogimenos if (SemaBuiltinUnorderedCompare(TheCall)) 1712cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return ExprError(); 1722cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 1732cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_fpclassify: 1742cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (SemaBuiltinFPClassification(TheCall, 6)) 1752cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return ExprError(); 1762cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 1772cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_isfinite: 1782cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_isinf: 1792cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_isinf_sign: 1802cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_isnan: 1812cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_isnormal: 1822cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (SemaBuiltinFPClassification(TheCall, 1)) 1832cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return ExprError(); 1842cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 1852cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_shufflevector: 1862cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return SemaBuiltinShuffleVector(TheCall); 1872cca3008e86aa5448a629c744064daecb531bf94Chris Lattner // TheCall will be freed by the smart pointer here, but that's fine, since 1882cca3008e86aa5448a629c744064daecb531bf94Chris Lattner // SemaBuiltinShuffleVector guts it, but then doesn't release it. 1892cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_prefetch: 1902cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (SemaBuiltinPrefetch(TheCall)) 1912cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return ExprError(); 1922cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 1932cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_object_size: 1942cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (SemaBuiltinObjectSize(TheCall)) 1952cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return ExprError(); 1962cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 1972cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_longjmp: 1982cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (SemaBuiltinLongjmp(TheCall)) 1992cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return ExprError(); 2002cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 2012cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__builtin_constant_p: 2022cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (TheCall->getNumArgs() == 0) 2032cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 2042cca3008e86aa5448a629c744064daecb531bf94Chris Lattner << 0 /*function call*/ << 1 << 0 << TheCall->getSourceRange(); 2052cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (TheCall->getNumArgs() > 1) 2062cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return Diag(TheCall->getArg(1)->getLocStart(), 2072cca3008e86aa5448a629c744064daecb531bf94Chris Lattner diag::err_typecheck_call_too_many_args) 2082cca3008e86aa5448a629c744064daecb531bf94Chris Lattner << 0 /*function call*/ << 1 << TheCall->getNumArgs() 2092cca3008e86aa5448a629c744064daecb531bf94Chris Lattner << TheCall->getArg(1)->getSourceRange(); 2102cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 2112cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_fetch_and_add: 2122cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_fetch_and_sub: 2132cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_fetch_and_or: 2142cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_fetch_and_and: 2152cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_fetch_and_xor: 2162cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_add_and_fetch: 2172cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_sub_and_fetch: 2182cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_and_and_fetch: 2192cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_or_and_fetch: 2202cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_xor_and_fetch: 2212cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_val_compare_and_swap: 2227e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_bool_compare_and_swap: 2232cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_lock_test_and_set: 2242cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case Builtin::BI__sync_lock_release: 2252cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return SemaBuiltinAtomicOverloaded(move(TheCallResult)); 2262cca3008e86aa5448a629c744064daecb531bf94Chris Lattner } 2272cca3008e86aa5448a629c744064daecb531bf94Chris Lattner 2282cca3008e86aa5448a629c744064daecb531bf94Chris Lattner // Since the target specific builtins for each arch overlap, only check those 2292cca3008e86aa5448a629c744064daecb531bf94Chris Lattner // of the arch we are compiling for. 2302cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (BuiltinID >= Builtin::FirstTSBuiltin) { 2312cca3008e86aa5448a629c744064daecb531bf94Chris Lattner switch (Context.Target.getTriple().getArch()) { 2322cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case llvm::Triple::arm: 2332cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case llvm::Triple::thumb: 2342cca3008e86aa5448a629c744064daecb531bf94Chris Lattner if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall)) 2352cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return ExprError(); 2362cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 2372cca3008e86aa5448a629c744064daecb531bf94Chris Lattner default: 2382cca3008e86aa5448a629c744064daecb531bf94Chris Lattner break; 2392cca3008e86aa5448a629c744064daecb531bf94Chris Lattner } 2402cca3008e86aa5448a629c744064daecb531bf94Chris Lattner } 2412cca3008e86aa5448a629c744064daecb531bf94Chris Lattner 2422cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return move(TheCallResult); 2432cca3008e86aa5448a629c744064daecb531bf94Chris Lattner} 2442cca3008e86aa5448a629c744064daecb531bf94Chris Lattner 2452cca3008e86aa5448a629c744064daecb531bf94Chris Lattner// Get the valid immediate range for the specified NEON type code. 2462cca3008e86aa5448a629c744064daecb531bf94Chris Lattnerstatic unsigned RFT(unsigned t, bool shift = false) { 2472cca3008e86aa5448a629c744064daecb531bf94Chris Lattner bool quad = t & 0x10; 2482cca3008e86aa5448a629c744064daecb531bf94Chris Lattner 2492cca3008e86aa5448a629c744064daecb531bf94Chris Lattner switch (t & 0x7) { 2502cca3008e86aa5448a629c744064daecb531bf94Chris Lattner case 0: // i8 2512cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return shift ? 7 : (8 << (int)quad) - 1; 2527e70829632f82de15db187845666aaca6e04b792Chris Lattner case 1: // i16 2537e70829632f82de15db187845666aaca6e04b792Chris Lattner return shift ? 15 : (4 << (int)quad) - 1; 2547e70829632f82de15db187845666aaca6e04b792Chris Lattner case 2: // i32 2557e70829632f82de15db187845666aaca6e04b792Chris Lattner return shift ? 31 : (2 << (int)quad) - 1; 2567e70829632f82de15db187845666aaca6e04b792Chris Lattner case 3: // i64 2572cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return shift ? 63 : (1 << (int)quad) - 1; 258011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner case 4: // f32 259011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner assert(!shift && "cannot shift float types!"); 260011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner return (2 << (int)quad) - 1; 261011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner case 5: // poly8 262011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner assert(!shift && "cannot shift polynomial types!"); 263011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner return (8 << (int)quad) - 1; 264011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner case 6: // poly16 265011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner assert(!shift && "cannot shift polynomial types!"); 266011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner return (4 << (int)quad) - 1; 267011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner case 7: // float16 268011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner assert(!shift && "cannot shift float types!"); 269011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner return (4 << (int)quad) - 1; 270011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner } 271011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner return 0; 272011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner} 273011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner 274011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattnerbool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) { 275011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner llvm::APSInt Result; 276011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner 277011ce8d2e401855877803fb6d972a6f6c22242a5Chris Lattner unsigned mask = 0; 2787e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned TV = 0; 2797e70829632f82de15db187845666aaca6e04b792Chris Lattner switch (BuiltinID) { 2807e70829632f82de15db187845666aaca6e04b792Chris Lattner#define GET_NEON_OVERLOAD_CHECK 2817e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Basic/arm_neon.inc" 2827e70829632f82de15db187845666aaca6e04b792Chris Lattner#undef GET_NEON_OVERLOAD_CHECK 2837e70829632f82de15db187845666aaca6e04b792Chris Lattner } 2847e70829632f82de15db187845666aaca6e04b792Chris Lattner 2857e70829632f82de15db187845666aaca6e04b792Chris Lattner // For NEON intrinsics which are overloaded on vector element type, validate 2867e70829632f82de15db187845666aaca6e04b792Chris Lattner // the immediate which specifies which variant to emit. 2877e70829632f82de15db187845666aaca6e04b792Chris Lattner if (mask) { 2887e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned ArgNo = TheCall->getNumArgs()-1; 2897e70829632f82de15db187845666aaca6e04b792Chris Lattner if (SemaBuiltinConstantArg(TheCall, ArgNo, Result)) 2907e70829632f82de15db187845666aaca6e04b792Chris Lattner return true; 2917e70829632f82de15db187845666aaca6e04b792Chris Lattner 2927e70829632f82de15db187845666aaca6e04b792Chris Lattner TV = Result.getLimitedValue(32); 2937e70829632f82de15db187845666aaca6e04b792Chris Lattner if ((TV > 31) || (mask & (1 << TV)) == 0) 2947e70829632f82de15db187845666aaca6e04b792Chris Lattner return Diag(TheCall->getLocStart(), diag::err_invalid_neon_type_code) 2957e70829632f82de15db187845666aaca6e04b792Chris Lattner << TheCall->getArg(ArgNo)->getSourceRange(); 2967e70829632f82de15db187845666aaca6e04b792Chris Lattner } 2977e70829632f82de15db187845666aaca6e04b792Chris Lattner 2987e70829632f82de15db187845666aaca6e04b792Chris Lattner // For NEON intrinsics which take an immediate value as part of the 2997e70829632f82de15db187845666aaca6e04b792Chris Lattner // instruction, range check them here. 3007e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned i = 0, l = 0, u = 0; 3014a9f9337511441af0624e754ad9b2b1262ee584dAnand Shukla switch (BuiltinID) { 3024a9f9337511441af0624e754ad9b2b1262ee584dAnand Shukla default: return false; 3037e70829632f82de15db187845666aaca6e04b792Chris Lattner case ARM::BI__builtin_arm_ssat: i = 1; l = 1; u = 31; break; 30440c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner case ARM::BI__builtin_arm_usat: i = 1; u = 31; break; 3057e70829632f82de15db187845666aaca6e04b792Chris Lattner case ARM::BI__builtin_arm_vcvtr_f: 3067e70829632f82de15db187845666aaca6e04b792Chris Lattner case ARM::BI__builtin_arm_vcvtr_d: i = 1; u = 1; break; 3077e70829632f82de15db187845666aaca6e04b792Chris Lattner#define GET_NEON_IMMEDIATE_CHECK 3087e70829632f82de15db187845666aaca6e04b792Chris Lattner#include "clang/Basic/arm_neon.inc" 3097e70829632f82de15db187845666aaca6e04b792Chris Lattner#undef GET_NEON_IMMEDIATE_CHECK 3102cca3008e86aa5448a629c744064daecb531bf94Chris Lattner }; 3117e70829632f82de15db187845666aaca6e04b792Chris Lattner 3127e70829632f82de15db187845666aaca6e04b792Chris Lattner // Check that the immediate argument is actually a constant. 3137e70829632f82de15db187845666aaca6e04b792Chris Lattner if (SemaBuiltinConstantArg(TheCall, i, Result)) 3147e70829632f82de15db187845666aaca6e04b792Chris Lattner return true; 3157e70829632f82de15db187845666aaca6e04b792Chris Lattner 3162cca3008e86aa5448a629c744064daecb531bf94Chris Lattner // Range check against the upper/lower values for this isntruction. 3177e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned Val = Result.getZExtValue(); 3187e70829632f82de15db187845666aaca6e04b792Chris Lattner if (Val < l || Val > (u + l)) 3197e70829632f82de15db187845666aaca6e04b792Chris Lattner return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 3207e70829632f82de15db187845666aaca6e04b792Chris Lattner << l << u+l << TheCall->getArg(i)->getSourceRange(); 3217e70829632f82de15db187845666aaca6e04b792Chris Lattner 3222cca3008e86aa5448a629c744064daecb531bf94Chris Lattner // FIXME: VFP Intrinsics should error if VFP not present. 3232cca3008e86aa5448a629c744064daecb531bf94Chris Lattner return false; 3242cca3008e86aa5448a629c744064daecb531bf94Chris Lattner} 3252cca3008e86aa5448a629c744064daecb531bf94Chris Lattner 3262cca3008e86aa5448a629c744064daecb531bf94Chris Lattner/// CheckFunctionCall - Check a direct function call for various correctness 3272cca3008e86aa5448a629c744064daecb531bf94Chris Lattner/// and safety properties not strictly enforced by the C type system. 3282cca3008e86aa5448a629c744064daecb531bf94Chris Lattnerbool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall) { 3297e70829632f82de15db187845666aaca6e04b792Chris Lattner // Get the IdentifierInfo* for the called function. 3307e70829632f82de15db187845666aaca6e04b792Chris Lattner IdentifierInfo *FnInfo = FDecl->getIdentifier(); 3317e70829632f82de15db187845666aaca6e04b792Chris Lattner 3327e70829632f82de15db187845666aaca6e04b792Chris Lattner // None of the checks below are needed for functions that don't have 3337e70829632f82de15db187845666aaca6e04b792Chris Lattner // simple names (e.g., C++ conversion functions). 3347e70829632f82de15db187845666aaca6e04b792Chris Lattner if (!FnInfo) 3357e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 3367e70829632f82de15db187845666aaca6e04b792Chris Lattner 3377e70829632f82de15db187845666aaca6e04b792Chris Lattner // FIXME: This mechanism should be abstracted to be less fragile and 3387e70829632f82de15db187845666aaca6e04b792Chris Lattner // more efficient. For example, just map function ids to custom 3397e70829632f82de15db187845666aaca6e04b792Chris Lattner // handlers. 3407e70829632f82de15db187845666aaca6e04b792Chris Lattner 3417e70829632f82de15db187845666aaca6e04b792Chris Lattner // Printf and scanf checking. 3427e70829632f82de15db187845666aaca6e04b792Chris Lattner for (specific_attr_iterator<FormatAttr> 3437e70829632f82de15db187845666aaca6e04b792Chris Lattner i = FDecl->specific_attr_begin<FormatAttr>(), 3447e70829632f82de15db187845666aaca6e04b792Chris Lattner e = FDecl->specific_attr_end<FormatAttr>(); i != e ; ++i) { 3457e70829632f82de15db187845666aaca6e04b792Chris Lattner 3467e70829632f82de15db187845666aaca6e04b792Chris Lattner const FormatAttr *Format = *i; 3477e70829632f82de15db187845666aaca6e04b792Chris Lattner const bool b = Format->getType() == "scanf"; 3487e70829632f82de15db187845666aaca6e04b792Chris Lattner if (b || CheckablePrintfAttr(Format, TheCall)) { 3497e70829632f82de15db187845666aaca6e04b792Chris Lattner bool HasVAListArg = Format->getFirstArg() == 0; 3507e70829632f82de15db187845666aaca6e04b792Chris Lattner CheckPrintfScanfArguments(TheCall, HasVAListArg, 3517e70829632f82de15db187845666aaca6e04b792Chris Lattner Format->getFormatIdx() - 1, 3527e70829632f82de15db187845666aaca6e04b792Chris Lattner HasVAListArg ? 0 : Format->getFirstArg() - 1, 3537e70829632f82de15db187845666aaca6e04b792Chris Lattner !b); 3547e70829632f82de15db187845666aaca6e04b792Chris Lattner } 3557e70829632f82de15db187845666aaca6e04b792Chris Lattner } 3567e70829632f82de15db187845666aaca6e04b792Chris Lattner 3577e70829632f82de15db187845666aaca6e04b792Chris Lattner for (specific_attr_iterator<NonNullAttr> 3587e70829632f82de15db187845666aaca6e04b792Chris Lattner i = FDecl->specific_attr_begin<NonNullAttr>(), 3597e70829632f82de15db187845666aaca6e04b792Chris Lattner e = FDecl->specific_attr_end<NonNullAttr>(); i != e; ++i) { 3607e70829632f82de15db187845666aaca6e04b792Chris Lattner CheckNonNullArguments(*i, TheCall); 3617e70829632f82de15db187845666aaca6e04b792Chris Lattner } 3627e70829632f82de15db187845666aaca6e04b792Chris Lattner 3637e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 3647e70829632f82de15db187845666aaca6e04b792Chris Lattner} 3657e70829632f82de15db187845666aaca6e04b792Chris Lattner 3667e70829632f82de15db187845666aaca6e04b792Chris Lattnerbool Sema::CheckBlockCall(NamedDecl *NDecl, CallExpr *TheCall) { 3677e70829632f82de15db187845666aaca6e04b792Chris Lattner // Printf checking. 3687e70829632f82de15db187845666aaca6e04b792Chris Lattner const FormatAttr *Format = NDecl->getAttr<FormatAttr>(); 3697e70829632f82de15db187845666aaca6e04b792Chris Lattner if (!Format) 3707e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 3717e70829632f82de15db187845666aaca6e04b792Chris Lattner 3727e70829632f82de15db187845666aaca6e04b792Chris Lattner const VarDecl *V = dyn_cast<VarDecl>(NDecl); 3737e70829632f82de15db187845666aaca6e04b792Chris Lattner if (!V) 3747e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 3757e70829632f82de15db187845666aaca6e04b792Chris Lattner 3767e70829632f82de15db187845666aaca6e04b792Chris Lattner QualType Ty = V->getType(); 3777e70829632f82de15db187845666aaca6e04b792Chris Lattner if (!Ty->isBlockPointerType()) 3787e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 3797e70829632f82de15db187845666aaca6e04b792Chris Lattner 3807e70829632f82de15db187845666aaca6e04b792Chris Lattner const bool b = Format->getType() == "scanf"; 3817e70829632f82de15db187845666aaca6e04b792Chris Lattner if (!b && !CheckablePrintfAttr(Format, TheCall)) 3827e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 383825b02d5ee74031ca8f872a761a79b137225f818Chris Lattner 3847e70829632f82de15db187845666aaca6e04b792Chris Lattner bool HasVAListArg = Format->getFirstArg() == 0; 3857e70829632f82de15db187845666aaca6e04b792Chris Lattner CheckPrintfScanfArguments(TheCall, HasVAListArg, Format->getFormatIdx() - 1, 3867e70829632f82de15db187845666aaca6e04b792Chris Lattner HasVAListArg ? 0 : Format->getFirstArg() - 1, !b); 3877e70829632f82de15db187845666aaca6e04b792Chris Lattner 3887e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 3897e70829632f82de15db187845666aaca6e04b792Chris Lattner} 3907e70829632f82de15db187845666aaca6e04b792Chris Lattner 3917e70829632f82de15db187845666aaca6e04b792Chris Lattner/// SemaBuiltinAtomicOverloaded - We have a call to a function like 3927e70829632f82de15db187845666aaca6e04b792Chris Lattner/// __sync_fetch_and_add, which is an overloaded function based on the pointer 3937e70829632f82de15db187845666aaca6e04b792Chris Lattner/// type of its first argument. The main ActOnCallExpr routines have already 3947e70829632f82de15db187845666aaca6e04b792Chris Lattner/// promoted the types of arguments because all of these calls are prototyped as 3957e70829632f82de15db187845666aaca6e04b792Chris Lattner/// void(...). 3967e70829632f82de15db187845666aaca6e04b792Chris Lattner/// 3977e70829632f82de15db187845666aaca6e04b792Chris Lattner/// This function goes through and does final semantic checking for these 3987e70829632f82de15db187845666aaca6e04b792Chris Lattner/// builtins, 3997e70829632f82de15db187845666aaca6e04b792Chris LattnerExprResult 4007e70829632f82de15db187845666aaca6e04b792Chris LattnerSema::SemaBuiltinAtomicOverloaded(ExprResult TheCallResult) { 4017e70829632f82de15db187845666aaca6e04b792Chris Lattner CallExpr *TheCall = (CallExpr *)TheCallResult.get(); 4027e70829632f82de15db187845666aaca6e04b792Chris Lattner DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts()); 4037e70829632f82de15db187845666aaca6e04b792Chris Lattner FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl()); 4047e70829632f82de15db187845666aaca6e04b792Chris Lattner 4057e70829632f82de15db187845666aaca6e04b792Chris Lattner // Ensure that we have at least one argument to do type inference from. 4067e70829632f82de15db187845666aaca6e04b792Chris Lattner if (TheCall->getNumArgs() < 1) { 4077e70829632f82de15db187845666aaca6e04b792Chris Lattner Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least) 4087e70829632f82de15db187845666aaca6e04b792Chris Lattner << 0 << 1 << TheCall->getNumArgs() 4097e70829632f82de15db187845666aaca6e04b792Chris Lattner << TheCall->getCallee()->getSourceRange(); 4107e70829632f82de15db187845666aaca6e04b792Chris Lattner return ExprError(); 4117e70829632f82de15db187845666aaca6e04b792Chris Lattner } 4127e70829632f82de15db187845666aaca6e04b792Chris Lattner 4137e70829632f82de15db187845666aaca6e04b792Chris Lattner // Inspect the first argument of the atomic builtin. This should always be 4147e70829632f82de15db187845666aaca6e04b792Chris Lattner // a pointer type, whose element is an integral scalar or pointer type. 4157e70829632f82de15db187845666aaca6e04b792Chris Lattner // Because it is a pointer type, we don't have to worry about any implicit 4167e70829632f82de15db187845666aaca6e04b792Chris Lattner // casts here. 4177e70829632f82de15db187845666aaca6e04b792Chris Lattner // FIXME: We don't allow floating point scalars as input. 4187e70829632f82de15db187845666aaca6e04b792Chris Lattner Expr *FirstArg = TheCall->getArg(0); 4197e70829632f82de15db187845666aaca6e04b792Chris Lattner if (!FirstArg->getType()->isPointerType()) { 4207e70829632f82de15db187845666aaca6e04b792Chris Lattner Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer) 4217e70829632f82de15db187845666aaca6e04b792Chris Lattner << FirstArg->getType() << FirstArg->getSourceRange(); 4227e70829632f82de15db187845666aaca6e04b792Chris Lattner return ExprError(); 4237e70829632f82de15db187845666aaca6e04b792Chris Lattner } 4247e70829632f82de15db187845666aaca6e04b792Chris Lattner 4257e70829632f82de15db187845666aaca6e04b792Chris Lattner QualType ValType = 4267e70829632f82de15db187845666aaca6e04b792Chris Lattner FirstArg->getType()->getAs<PointerType>()->getPointeeType(); 4277e70829632f82de15db187845666aaca6e04b792Chris Lattner if (!ValType->isIntegerType() && !ValType->isAnyPointerType() && 4287e70829632f82de15db187845666aaca6e04b792Chris Lattner !ValType->isBlockPointerType()) { 4297e70829632f82de15db187845666aaca6e04b792Chris Lattner Diag(DRE->getLocStart(), diag::err_atomic_builtin_must_be_pointer_intptr) 4307e70829632f82de15db187845666aaca6e04b792Chris Lattner << FirstArg->getType() << FirstArg->getSourceRange(); 4317e70829632f82de15db187845666aaca6e04b792Chris Lattner return ExprError(); 4327e70829632f82de15db187845666aaca6e04b792Chris Lattner } 4337e70829632f82de15db187845666aaca6e04b792Chris Lattner 4347e70829632f82de15db187845666aaca6e04b792Chris Lattner // The majority of builtins return a value, but a few have special return 4357e70829632f82de15db187845666aaca6e04b792Chris Lattner // types, so allow them to override appropriately below. 4367e70829632f82de15db187845666aaca6e04b792Chris Lattner QualType ResultType = ValType; 4377e70829632f82de15db187845666aaca6e04b792Chris Lattner 4387e70829632f82de15db187845666aaca6e04b792Chris Lattner // We need to figure out which concrete builtin this maps onto. For example, 4397e70829632f82de15db187845666aaca6e04b792Chris Lattner // __sync_fetch_and_add with a 2 byte object turns into 4407e70829632f82de15db187845666aaca6e04b792Chris Lattner // __sync_fetch_and_add_2. 441a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner#define BUILTIN_ROW(x) \ 442a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner { Builtin::BI##x##_1, Builtin::BI##x##_2, Builtin::BI##x##_4, \ 443a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner Builtin::BI##x##_8, Builtin::BI##x##_16 } 4447e70829632f82de15db187845666aaca6e04b792Chris Lattner 4457e70829632f82de15db187845666aaca6e04b792Chris Lattner static const unsigned BuiltinIndices[][5] = { 446a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner BUILTIN_ROW(__sync_fetch_and_add), 4477e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_fetch_and_sub), 4487e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_fetch_and_or), 4497e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_fetch_and_and), 4507e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_fetch_and_xor), 4517e70829632f82de15db187845666aaca6e04b792Chris Lattner 4527e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_add_and_fetch), 4537e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_sub_and_fetch), 4547e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_and_and_fetch), 4557e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_or_and_fetch), 4567e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_xor_and_fetch), 4577e70829632f82de15db187845666aaca6e04b792Chris Lattner 4587e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_val_compare_and_swap), 4597e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_bool_compare_and_swap), 4607e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_lock_test_and_set), 4617e70829632f82de15db187845666aaca6e04b792Chris Lattner BUILTIN_ROW(__sync_lock_release) 4627e70829632f82de15db187845666aaca6e04b792Chris Lattner }; 4637e70829632f82de15db187845666aaca6e04b792Chris Lattner#undef BUILTIN_ROW 4647e70829632f82de15db187845666aaca6e04b792Chris Lattner 4657e70829632f82de15db187845666aaca6e04b792Chris Lattner // Determine the index of the size. 4667e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned SizeIndex; 4677e70829632f82de15db187845666aaca6e04b792Chris Lattner switch (Context.getTypeSizeInChars(ValType).getQuantity()) { 4687e70829632f82de15db187845666aaca6e04b792Chris Lattner case 1: SizeIndex = 0; break; 4697e70829632f82de15db187845666aaca6e04b792Chris Lattner case 2: SizeIndex = 1; break; 4707e70829632f82de15db187845666aaca6e04b792Chris Lattner case 4: SizeIndex = 2; break; 4717e70829632f82de15db187845666aaca6e04b792Chris Lattner case 8: SizeIndex = 3; break; 4727e70829632f82de15db187845666aaca6e04b792Chris Lattner case 16: SizeIndex = 4; break; 4737e70829632f82de15db187845666aaca6e04b792Chris Lattner default: 4747e70829632f82de15db187845666aaca6e04b792Chris Lattner Diag(DRE->getLocStart(), diag::err_atomic_builtin_pointer_size) 4757e70829632f82de15db187845666aaca6e04b792Chris Lattner << FirstArg->getType() << FirstArg->getSourceRange(); 4767e70829632f82de15db187845666aaca6e04b792Chris Lattner return ExprError(); 4777e70829632f82de15db187845666aaca6e04b792Chris Lattner } 4787e70829632f82de15db187845666aaca6e04b792Chris Lattner 4797e70829632f82de15db187845666aaca6e04b792Chris Lattner // Each of these builtins has one pointer argument, followed by some number of 4807e70829632f82de15db187845666aaca6e04b792Chris Lattner // values (0, 1 or 2) followed by a potentially empty varags list of stuff 4817e70829632f82de15db187845666aaca6e04b792Chris Lattner // that we ignore. Find out which row of BuiltinIndices to read from as well 4827e70829632f82de15db187845666aaca6e04b792Chris Lattner // as the number of fixed args. 4837e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned BuiltinID = FDecl->getBuiltinID(); 4847e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned BuiltinIndex, NumFixed = 1; 4857e70829632f82de15db187845666aaca6e04b792Chris Lattner switch (BuiltinID) { 4867e70829632f82de15db187845666aaca6e04b792Chris Lattner default: assert(0 && "Unknown overloaded atomic builtin!"); 4877e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_fetch_and_add: BuiltinIndex = 0; break; 4887e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_fetch_and_sub: BuiltinIndex = 1; break; 4897e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_fetch_and_or: BuiltinIndex = 2; break; 4907e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_fetch_and_and: BuiltinIndex = 3; break; 4917e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_fetch_and_xor: BuiltinIndex = 4; break; 4927e70829632f82de15db187845666aaca6e04b792Chris Lattner 4937e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_add_and_fetch: BuiltinIndex = 5; break; 4947e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_sub_and_fetch: BuiltinIndex = 6; break; 4957e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_and_and_fetch: BuiltinIndex = 7; break; 4967e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_or_and_fetch: BuiltinIndex = 8; break; 4977e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_xor_and_fetch: BuiltinIndex = 9; break; 4987e70829632f82de15db187845666aaca6e04b792Chris Lattner 4997e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_val_compare_and_swap: 5007e70829632f82de15db187845666aaca6e04b792Chris Lattner BuiltinIndex = 10; 5017e70829632f82de15db187845666aaca6e04b792Chris Lattner NumFixed = 2; 5027e70829632f82de15db187845666aaca6e04b792Chris Lattner break; 5037e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_bool_compare_and_swap: 5047e70829632f82de15db187845666aaca6e04b792Chris Lattner BuiltinIndex = 11; 5057e70829632f82de15db187845666aaca6e04b792Chris Lattner NumFixed = 2; 5067e70829632f82de15db187845666aaca6e04b792Chris Lattner ResultType = Context.BoolTy; 5077e70829632f82de15db187845666aaca6e04b792Chris Lattner break; 5087e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_lock_test_and_set: BuiltinIndex = 12; break; 5097e70829632f82de15db187845666aaca6e04b792Chris Lattner case Builtin::BI__sync_lock_release: 5107e70829632f82de15db187845666aaca6e04b792Chris Lattner BuiltinIndex = 13; 5117e70829632f82de15db187845666aaca6e04b792Chris Lattner NumFixed = 0; 5127e70829632f82de15db187845666aaca6e04b792Chris Lattner ResultType = Context.VoidTy; 5137e70829632f82de15db187845666aaca6e04b792Chris Lattner break; 5147e70829632f82de15db187845666aaca6e04b792Chris Lattner } 5157e70829632f82de15db187845666aaca6e04b792Chris Lattner 5167e70829632f82de15db187845666aaca6e04b792Chris Lattner // Now that we know how many fixed arguments we expect, first check that we 5177e70829632f82de15db187845666aaca6e04b792Chris Lattner // have at least that many. 5187e70829632f82de15db187845666aaca6e04b792Chris Lattner if (TheCall->getNumArgs() < 1+NumFixed) { 5197e70829632f82de15db187845666aaca6e04b792Chris Lattner Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least) 5207e70829632f82de15db187845666aaca6e04b792Chris Lattner << 0 << 1+NumFixed << TheCall->getNumArgs() 5217e70829632f82de15db187845666aaca6e04b792Chris Lattner << TheCall->getCallee()->getSourceRange(); 5227e70829632f82de15db187845666aaca6e04b792Chris Lattner return ExprError(); 5237e70829632f82de15db187845666aaca6e04b792Chris Lattner } 5247e70829632f82de15db187845666aaca6e04b792Chris Lattner 5257e70829632f82de15db187845666aaca6e04b792Chris Lattner // Get the decl for the concrete builtin from this, we can tell what the 5267e70829632f82de15db187845666aaca6e04b792Chris Lattner // concrete integer type we should convert to is. 5277e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned NewBuiltinID = BuiltinIndices[BuiltinIndex][SizeIndex]; 5287e70829632f82de15db187845666aaca6e04b792Chris Lattner const char *NewBuiltinName = Context.BuiltinInfo.GetName(NewBuiltinID); 5297e70829632f82de15db187845666aaca6e04b792Chris Lattner IdentifierInfo *NewBuiltinII = PP.getIdentifierInfo(NewBuiltinName); 5307e70829632f82de15db187845666aaca6e04b792Chris Lattner FunctionDecl *NewBuiltinDecl = 5317e70829632f82de15db187845666aaca6e04b792Chris Lattner cast<FunctionDecl>(LazilyCreateBuiltin(NewBuiltinII, NewBuiltinID, 5327e70829632f82de15db187845666aaca6e04b792Chris Lattner TUScope, false, DRE->getLocStart())); 5337e70829632f82de15db187845666aaca6e04b792Chris Lattner 5347e70829632f82de15db187845666aaca6e04b792Chris Lattner // The first argument --- the pointer --- has a fixed type; we 5357e70829632f82de15db187845666aaca6e04b792Chris Lattner // deduce the types of the rest of the arguments accordingly. Walk 5367e70829632f82de15db187845666aaca6e04b792Chris Lattner // the remaining arguments, converting them to the deduced value type. 5377e70829632f82de15db187845666aaca6e04b792Chris Lattner for (unsigned i = 0; i != NumFixed; ++i) { 5387e70829632f82de15db187845666aaca6e04b792Chris Lattner Expr *Arg = TheCall->getArg(i+1); 5397e70829632f82de15db187845666aaca6e04b792Chris Lattner 5407e70829632f82de15db187845666aaca6e04b792Chris Lattner // If the argument is an implicit cast, then there was a promotion due to 5417e70829632f82de15db187845666aaca6e04b792Chris Lattner // "...", just remove it now. 5427e70829632f82de15db187845666aaca6e04b792Chris Lattner if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) { 5437e70829632f82de15db187845666aaca6e04b792Chris Lattner Arg = ICE->getSubExpr(); 5447e70829632f82de15db187845666aaca6e04b792Chris Lattner ICE->setSubExpr(0); 5457e70829632f82de15db187845666aaca6e04b792Chris Lattner TheCall->setArg(i+1, Arg); 5467e70829632f82de15db187845666aaca6e04b792Chris Lattner } 5477e70829632f82de15db187845666aaca6e04b792Chris Lattner 548a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner // GCC does an implicit conversion to the pointer or integer ValType. This 549a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner // can fail in some cases (1i -> int**), check for this error case now. 550a1cb4737b04a92f57b1b9dcd8a24c68db5035401Chris Lattner CastKind Kind = CK_Unknown; 5517e70829632f82de15db187845666aaca6e04b792Chris Lattner CXXCastPath BasePath; 5527e70829632f82de15db187845666aaca6e04b792Chris Lattner if (CheckCastTypes(Arg->getSourceRange(), ValType, Arg, Kind, BasePath)) 55340c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner return ExprError(); 5547e70829632f82de15db187845666aaca6e04b792Chris Lattner 5557e70829632f82de15db187845666aaca6e04b792Chris Lattner // Okay, we have something that *can* be converted to the right type. Check 55640c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner // to see if there is a potentially weird extension going on here. This can 5577e70829632f82de15db187845666aaca6e04b792Chris Lattner // happen when you do an atomic operation on something like an char* and 5587e70829632f82de15db187845666aaca6e04b792Chris Lattner // pass in 42. The 42 gets converted to char. This is even more strange 55940c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner // for things like 45.123 -> char, etc. 5607e70829632f82de15db187845666aaca6e04b792Chris Lattner // FIXME: Do this check. 5617e70829632f82de15db187845666aaca6e04b792Chris Lattner ImpCastExprToType(Arg, ValType, Kind, VK_RValue, &BasePath); 56240c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner TheCall->setArg(i+1, Arg); 5637e70829632f82de15db187845666aaca6e04b792Chris Lattner } 5647e70829632f82de15db187845666aaca6e04b792Chris Lattner 5657e70829632f82de15db187845666aaca6e04b792Chris Lattner // Switch the DeclRefExpr to refer to the new decl. 5667e70829632f82de15db187845666aaca6e04b792Chris Lattner DRE->setDecl(NewBuiltinDecl); 5677e70829632f82de15db187845666aaca6e04b792Chris Lattner DRE->setType(NewBuiltinDecl->getType()); 5687e70829632f82de15db187845666aaca6e04b792Chris Lattner 5697e70829632f82de15db187845666aaca6e04b792Chris Lattner // Set the callee in the CallExpr. 5707e70829632f82de15db187845666aaca6e04b792Chris Lattner // FIXME: This leaks the original parens and implicit casts. 5717e70829632f82de15db187845666aaca6e04b792Chris Lattner Expr *PromotedCall = DRE; 5727e70829632f82de15db187845666aaca6e04b792Chris Lattner UsualUnaryConversions(PromotedCall); 5737e70829632f82de15db187845666aaca6e04b792Chris Lattner TheCall->setCallee(PromotedCall); 5747e70829632f82de15db187845666aaca6e04b792Chris Lattner 5757e70829632f82de15db187845666aaca6e04b792Chris Lattner // Change the result type of the call to match the original value type. This 5767e70829632f82de15db187845666aaca6e04b792Chris Lattner // is arbitrary, but the codegen for these builtins ins design to handle it 5777e70829632f82de15db187845666aaca6e04b792Chris Lattner // gracefully. 5787e70829632f82de15db187845666aaca6e04b792Chris Lattner TheCall->setType(ResultType); 5797e70829632f82de15db187845666aaca6e04b792Chris Lattner 5807e70829632f82de15db187845666aaca6e04b792Chris Lattner return move(TheCallResult); 58140c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner} 58240c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner 5837e70829632f82de15db187845666aaca6e04b792Chris Lattner 5847e70829632f82de15db187845666aaca6e04b792Chris Lattner/// CheckObjCString - Checks that the argument to the builtin 5857e70829632f82de15db187845666aaca6e04b792Chris Lattner/// CFString constructor is correct 5867e70829632f82de15db187845666aaca6e04b792Chris Lattner/// Note: It might also make sense to do the UTF-16 conversion here (would 5877e70829632f82de15db187845666aaca6e04b792Chris Lattner/// simplify the backend). 5887e70829632f82de15db187845666aaca6e04b792Chris Lattnerbool Sema::CheckObjCString(Expr *Arg) { 5897e70829632f82de15db187845666aaca6e04b792Chris Lattner Arg = Arg->IgnoreParenCasts(); 5907e70829632f82de15db187845666aaca6e04b792Chris Lattner StringLiteral *Literal = dyn_cast<StringLiteral>(Arg); 5917e70829632f82de15db187845666aaca6e04b792Chris Lattner 5927e70829632f82de15db187845666aaca6e04b792Chris Lattner if (!Literal || Literal->isWide()) { 5937e70829632f82de15db187845666aaca6e04b792Chris Lattner Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant) 59440c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner << Arg->getSourceRange(); 59540c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner return true; 5967e70829632f82de15db187845666aaca6e04b792Chris Lattner } 5977e70829632f82de15db187845666aaca6e04b792Chris Lattner 59840c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner size_t NulPos = Literal->getString().find('\0'); 5997e70829632f82de15db187845666aaca6e04b792Chris Lattner if (NulPos != llvm::StringRef::npos) { 60040c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner Diag(getLocationOfStringLiteralByte(Literal, NulPos), 6017e70829632f82de15db187845666aaca6e04b792Chris Lattner diag::warn_cfstring_literal_contains_nul_character) 60240c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner << Arg->getSourceRange(); 60340c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner } 6047e70829632f82de15db187845666aaca6e04b792Chris Lattner if (Literal->containsNonAsciiOrNull()) { 6057e70829632f82de15db187845666aaca6e04b792Chris Lattner llvm::StringRef String = Literal->getString(); 6067e70829632f82de15db187845666aaca6e04b792Chris Lattner unsigned NumBytes = String.size(); 6077e70829632f82de15db187845666aaca6e04b792Chris Lattner llvm::SmallVector<UTF16, 128> ToBuf(NumBytes); 6087e70829632f82de15db187845666aaca6e04b792Chris Lattner const UTF8 *FromPtr = (UTF8 *)String.data(); 6097e70829632f82de15db187845666aaca6e04b792Chris Lattner UTF16 *ToPtr = &ToBuf[0]; 6107e70829632f82de15db187845666aaca6e04b792Chris Lattner 6117e70829632f82de15db187845666aaca6e04b792Chris Lattner ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 6127e70829632f82de15db187845666aaca6e04b792Chris Lattner &ToPtr, ToPtr + NumBytes, 6137e70829632f82de15db187845666aaca6e04b792Chris Lattner strictConversion); 6147e70829632f82de15db187845666aaca6e04b792Chris Lattner // Check for conversion failure. 61540c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner if (Result != conversionOK) 6167e70829632f82de15db187845666aaca6e04b792Chris Lattner Diag(Arg->getLocStart(), 61740c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner diag::warn_cfstring_truncated) << Arg->getSourceRange(); 6187e70829632f82de15db187845666aaca6e04b792Chris Lattner } 6197e70829632f82de15db187845666aaca6e04b792Chris Lattner return false; 62040c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner} 6217e70829632f82de15db187845666aaca6e04b792Chris Lattner 62240c6fb6cac80367c2bec32295d4448e540f2d253Chris Lattner/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity. 6237e70829632f82de15db187845666aaca6e04b792Chris Lattner/// Emit an error and return true on failure, return false on success. 6247e70829632f82de15db187845666aaca6e04b792Chris Lattnerbool Sema::SemaBuiltinVAStart(CallExpr *TheCall) { 6257e70829632f82de15db187845666aaca6e04b792Chris Lattner Expr *Fn = TheCall->getCallee(); 6267e70829632f82de15db187845666aaca6e04b792Chris Lattner if (TheCall->getNumArgs() > 2) { 627d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke Diag(TheCall->getArg(2)->getLocStart(), 628d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke diag::err_typecheck_call_too_many_args) 6297e70829632f82de15db187845666aaca6e04b792Chris Lattner << 0 /*function call*/ << 2 << TheCall->getNumArgs() 6307e70829632f82de15db187845666aaca6e04b792Chris Lattner << Fn->getSourceRange() 6317e70829632f82de15db187845666aaca6e04b792Chris Lattner << SourceRange(TheCall->getArg(2)->getLocStart(), 632d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke (*(TheCall->arg_end()-1))->getLocEnd()); 6337e70829632f82de15db187845666aaca6e04b792Chris Lattner return true; 6347e70829632f82de15db187845666aaca6e04b792Chris Lattner } 6357e70829632f82de15db187845666aaca6e04b792Chris Lattner 6367e70829632f82de15db187845666aaca6e04b792Chris Lattner if (TheCall->getNumArgs() < 2) { 6377e70829632f82de15db187845666aaca6e04b792Chris Lattner return Diag(TheCall->getLocEnd(), 638 diag::err_typecheck_call_too_few_args_at_least) 639 << 0 /*function call*/ << 2 << TheCall->getNumArgs(); 640 } 641 642 // Determine whether the current function is variadic or not. 643 BlockScopeInfo *CurBlock = getCurBlock(); 644 bool isVariadic; 645 if (CurBlock) 646 isVariadic = CurBlock->TheDecl->isVariadic(); 647 else if (FunctionDecl *FD = getCurFunctionDecl()) 648 isVariadic = FD->isVariadic(); 649 else 650 isVariadic = getCurMethodDecl()->isVariadic(); 651 652 if (!isVariadic) { 653 Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function); 654 return true; 655 } 656 657 // Verify that the second argument to the builtin is the last argument of the 658 // current function or method. 659 bool SecondArgIsLastNamedArgument = false; 660 const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts(); 661 662 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) { 663 if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) { 664 // FIXME: This isn't correct for methods (results in bogus warning). 665 // Get the last formal in the current function. 666 const ParmVarDecl *LastArg; 667 if (CurBlock) 668 LastArg = *(CurBlock->TheDecl->param_end()-1); 669 else if (FunctionDecl *FD = getCurFunctionDecl()) 670 LastArg = *(FD->param_end()-1); 671 else 672 LastArg = *(getCurMethodDecl()->param_end()-1); 673 SecondArgIsLastNamedArgument = PV == LastArg; 674 } 675 } 676 677 if (!SecondArgIsLastNamedArgument) 678 Diag(TheCall->getArg(1)->getLocStart(), 679 diag::warn_second_parameter_of_va_start_not_last_named_argument); 680 return false; 681} 682 683/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and 684/// friends. This is declared to take (...), so we have to check everything. 685bool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) { 686 if (TheCall->getNumArgs() < 2) 687 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 688 << 0 << 2 << TheCall->getNumArgs()/*function call*/; 689 if (TheCall->getNumArgs() > 2) 690 return Diag(TheCall->getArg(2)->getLocStart(), 691 diag::err_typecheck_call_too_many_args) 692 << 0 /*function call*/ << 2 << TheCall->getNumArgs() 693 << SourceRange(TheCall->getArg(2)->getLocStart(), 694 (*(TheCall->arg_end()-1))->getLocEnd()); 695 696 Expr *OrigArg0 = TheCall->getArg(0); 697 Expr *OrigArg1 = TheCall->getArg(1); 698 699 // Do standard promotions between the two arguments, returning their common 700 // type. 701 QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false); 702 703 // Make sure any conversions are pushed back into the call; this is 704 // type safe since unordered compare builtins are declared as "_Bool 705 // foo(...)". 706 TheCall->setArg(0, OrigArg0); 707 TheCall->setArg(1, OrigArg1); 708 709 if (OrigArg0->isTypeDependent() || OrigArg1->isTypeDependent()) 710 return false; 711 712 // If the common type isn't a real floating type, then the arguments were 713 // invalid for this operation. 714 if (!Res->isRealFloatingType()) 715 return Diag(OrigArg0->getLocStart(), 716 diag::err_typecheck_call_invalid_ordered_compare) 717 << OrigArg0->getType() << OrigArg1->getType() 718 << SourceRange(OrigArg0->getLocStart(), OrigArg1->getLocEnd()); 719 720 return false; 721} 722 723/// SemaBuiltinSemaBuiltinFPClassification - Handle functions like 724/// __builtin_isnan and friends. This is declared to take (...), so we have 725/// to check everything. We expect the last argument to be a floating point 726/// value. 727bool Sema::SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs) { 728 if (TheCall->getNumArgs() < NumArgs) 729 return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 730 << 0 << NumArgs << TheCall->getNumArgs()/*function call*/; 731 if (TheCall->getNumArgs() > NumArgs) 732 return Diag(TheCall->getArg(NumArgs)->getLocStart(), 733 diag::err_typecheck_call_too_many_args) 734 << 0 /*function call*/ << NumArgs << TheCall->getNumArgs() 735 << SourceRange(TheCall->getArg(NumArgs)->getLocStart(), 736 (*(TheCall->arg_end()-1))->getLocEnd()); 737 738 Expr *OrigArg = TheCall->getArg(NumArgs-1); 739 740 if (OrigArg->isTypeDependent()) 741 return false; 742 743 // This operation requires a non-_Complex floating-point number. 744 if (!OrigArg->getType()->isRealFloatingType()) 745 return Diag(OrigArg->getLocStart(), 746 diag::err_typecheck_call_invalid_unary_fp) 747 << OrigArg->getType() << OrigArg->getSourceRange(); 748 749 // If this is an implicit conversion from float -> double, remove it. 750 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(OrigArg)) { 751 Expr *CastArg = Cast->getSubExpr(); 752 if (CastArg->getType()->isSpecificBuiltinType(BuiltinType::Float)) { 753 assert(Cast->getType()->isSpecificBuiltinType(BuiltinType::Double) && 754 "promotion from float to double is the only expected cast here"); 755 Cast->setSubExpr(0); 756 TheCall->setArg(NumArgs-1, CastArg); 757 OrigArg = CastArg; 758 } 759 } 760 761 return false; 762} 763 764/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector. 765// This is declared to take (...), so we have to check everything. 766ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) { 767 if (TheCall->getNumArgs() < 2) 768 return ExprError(Diag(TheCall->getLocEnd(), 769 diag::err_typecheck_call_too_few_args_at_least) 770 << 0 /*function call*/ << 2 << TheCall->getNumArgs() 771 << TheCall->getSourceRange()); 772 773 // Determine which of the following types of shufflevector we're checking: 774 // 1) unary, vector mask: (lhs, mask) 775 // 2) binary, vector mask: (lhs, rhs, mask) 776 // 3) binary, scalar mask: (lhs, rhs, index, ..., index) 777 QualType resType = TheCall->getArg(0)->getType(); 778 unsigned numElements = 0; 779 780 if (!TheCall->getArg(0)->isTypeDependent() && 781 !TheCall->getArg(1)->isTypeDependent()) { 782 QualType LHSType = TheCall->getArg(0)->getType(); 783 QualType RHSType = TheCall->getArg(1)->getType(); 784 785 if (!LHSType->isVectorType() || !RHSType->isVectorType()) { 786 Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector) 787 << SourceRange(TheCall->getArg(0)->getLocStart(), 788 TheCall->getArg(1)->getLocEnd()); 789 return ExprError(); 790 } 791 792 numElements = LHSType->getAs<VectorType>()->getNumElements(); 793 unsigned numResElements = TheCall->getNumArgs() - 2; 794 795 // Check to see if we have a call with 2 vector arguments, the unary shuffle 796 // with mask. If so, verify that RHS is an integer vector type with the 797 // same number of elts as lhs. 798 if (TheCall->getNumArgs() == 2) { 799 if (!RHSType->hasIntegerRepresentation() || 800 RHSType->getAs<VectorType>()->getNumElements() != numElements) 801 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector) 802 << SourceRange(TheCall->getArg(1)->getLocStart(), 803 TheCall->getArg(1)->getLocEnd()); 804 numResElements = numElements; 805 } 806 else if (!Context.hasSameUnqualifiedType(LHSType, RHSType)) { 807 Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector) 808 << SourceRange(TheCall->getArg(0)->getLocStart(), 809 TheCall->getArg(1)->getLocEnd()); 810 return ExprError(); 811 } else if (numElements != numResElements) { 812 QualType eltType = LHSType->getAs<VectorType>()->getElementType(); 813 resType = Context.getVectorType(eltType, numResElements, 814 VectorType::NotAltiVec); 815 } 816 } 817 818 for (unsigned i = 2; i < TheCall->getNumArgs(); i++) { 819 if (TheCall->getArg(i)->isTypeDependent() || 820 TheCall->getArg(i)->isValueDependent()) 821 continue; 822 823 llvm::APSInt Result(32); 824 if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context)) 825 return ExprError(Diag(TheCall->getLocStart(), 826 diag::err_shufflevector_nonconstant_argument) 827 << TheCall->getArg(i)->getSourceRange()); 828 829 if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2) 830 return ExprError(Diag(TheCall->getLocStart(), 831 diag::err_shufflevector_argument_too_large) 832 << TheCall->getArg(i)->getSourceRange()); 833 } 834 835 llvm::SmallVector<Expr*, 32> exprs; 836 837 for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) { 838 exprs.push_back(TheCall->getArg(i)); 839 TheCall->setArg(i, 0); 840 } 841 842 return Owned(new (Context) ShuffleVectorExpr(Context, exprs.begin(), 843 exprs.size(), resType, 844 TheCall->getCallee()->getLocStart(), 845 TheCall->getRParenLoc())); 846} 847 848/// SemaBuiltinPrefetch - Handle __builtin_prefetch. 849// This is declared to take (const void*, ...) and can take two 850// optional constant int args. 851bool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) { 852 unsigned NumArgs = TheCall->getNumArgs(); 853 854 if (NumArgs > 3) 855 return Diag(TheCall->getLocEnd(), 856 diag::err_typecheck_call_too_many_args_at_most) 857 << 0 /*function call*/ << 3 << NumArgs 858 << TheCall->getSourceRange(); 859 860 // Argument 0 is checked for us and the remaining arguments must be 861 // constant integers. 862 for (unsigned i = 1; i != NumArgs; ++i) { 863 Expr *Arg = TheCall->getArg(i); 864 865 llvm::APSInt Result; 866 if (SemaBuiltinConstantArg(TheCall, i, Result)) 867 return true; 868 869 // FIXME: gcc issues a warning and rewrites these to 0. These 870 // seems especially odd for the third argument since the default 871 // is 3. 872 if (i == 1) { 873 if (Result.getLimitedValue() > 1) 874 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 875 << "0" << "1" << Arg->getSourceRange(); 876 } else { 877 if (Result.getLimitedValue() > 3) 878 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 879 << "0" << "3" << Arg->getSourceRange(); 880 } 881 } 882 883 return false; 884} 885 886/// SemaBuiltinConstantArg - Handle a check if argument ArgNum of CallExpr 887/// TheCall is a constant expression. 888bool Sema::SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum, 889 llvm::APSInt &Result) { 890 Expr *Arg = TheCall->getArg(ArgNum); 891 DeclRefExpr *DRE =cast<DeclRefExpr>(TheCall->getCallee()->IgnoreParenCasts()); 892 FunctionDecl *FDecl = cast<FunctionDecl>(DRE->getDecl()); 893 894 if (Arg->isTypeDependent() || Arg->isValueDependent()) return false; 895 896 if (!Arg->isIntegerConstantExpr(Result, Context)) 897 return Diag(TheCall->getLocStart(), diag::err_constant_integer_arg_type) 898 << FDecl->getDeclName() << Arg->getSourceRange(); 899 900 return false; 901} 902 903/// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr, 904/// int type). This simply type checks that type is one of the defined 905/// constants (0-3). 906// For compatability check 0-3, llvm only handles 0 and 2. 907bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) { 908 llvm::APSInt Result; 909 910 // Check constant-ness first. 911 if (SemaBuiltinConstantArg(TheCall, 1, Result)) 912 return true; 913 914 Expr *Arg = TheCall->getArg(1); 915 if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) { 916 return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 917 << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 918 } 919 920 return false; 921} 922 923/// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val). 924/// This checks that val is a constant 1. 925bool Sema::SemaBuiltinLongjmp(CallExpr *TheCall) { 926 Expr *Arg = TheCall->getArg(1); 927 llvm::APSInt Result; 928 929 // TODO: This is less than ideal. Overload this to take a value. 930 if (SemaBuiltinConstantArg(TheCall, 1, Result)) 931 return true; 932 933 if (Result != 1) 934 return Diag(TheCall->getLocStart(), diag::err_builtin_longjmp_invalid_val) 935 << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 936 937 return false; 938} 939 940// Handle i > 1 ? "x" : "y", recursivelly 941bool Sema::SemaCheckStringLiteral(const Expr *E, const CallExpr *TheCall, 942 bool HasVAListArg, 943 unsigned format_idx, unsigned firstDataArg, 944 bool isPrintf) { 945 tryAgain: 946 if (E->isTypeDependent() || E->isValueDependent()) 947 return false; 948 949 switch (E->getStmtClass()) { 950 case Stmt::ConditionalOperatorClass: { 951 const ConditionalOperator *C = cast<ConditionalOperator>(E); 952 return SemaCheckStringLiteral(C->getTrueExpr(), TheCall, HasVAListArg, 953 format_idx, firstDataArg, isPrintf) 954 && SemaCheckStringLiteral(C->getRHS(), TheCall, HasVAListArg, 955 format_idx, firstDataArg, isPrintf); 956 } 957 958 case Stmt::IntegerLiteralClass: 959 // Technically -Wformat-nonliteral does not warn about this case. 960 // The behavior of printf and friends in this case is implementation 961 // dependent. Ideally if the format string cannot be null then 962 // it should have a 'nonnull' attribute in the function prototype. 963 return true; 964 965 case Stmt::ImplicitCastExprClass: { 966 E = cast<ImplicitCastExpr>(E)->getSubExpr(); 967 goto tryAgain; 968 } 969 970 case Stmt::ParenExprClass: { 971 E = cast<ParenExpr>(E)->getSubExpr(); 972 goto tryAgain; 973 } 974 975 case Stmt::DeclRefExprClass: { 976 const DeclRefExpr *DR = cast<DeclRefExpr>(E); 977 978 // As an exception, do not flag errors for variables binding to 979 // const string literals. 980 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) { 981 bool isConstant = false; 982 QualType T = DR->getType(); 983 984 if (const ArrayType *AT = Context.getAsArrayType(T)) { 985 isConstant = AT->getElementType().isConstant(Context); 986 } else if (const PointerType *PT = T->getAs<PointerType>()) { 987 isConstant = T.isConstant(Context) && 988 PT->getPointeeType().isConstant(Context); 989 } 990 991 if (isConstant) { 992 if (const Expr *Init = VD->getAnyInitializer()) 993 return SemaCheckStringLiteral(Init, TheCall, 994 HasVAListArg, format_idx, firstDataArg, 995 isPrintf); 996 } 997 998 // For vprintf* functions (i.e., HasVAListArg==true), we add a 999 // special check to see if the format string is a function parameter 1000 // of the function calling the printf function. If the function 1001 // has an attribute indicating it is a printf-like function, then we 1002 // should suppress warnings concerning non-literals being used in a call 1003 // to a vprintf function. For example: 1004 // 1005 // void 1006 // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...){ 1007 // va_list ap; 1008 // va_start(ap, fmt); 1009 // vprintf(fmt, ap); // Do NOT emit a warning about "fmt". 1010 // ... 1011 // 1012 // 1013 // FIXME: We don't have full attribute support yet, so just check to see 1014 // if the argument is a DeclRefExpr that references a parameter. We'll 1015 // add proper support for checking the attribute later. 1016 if (HasVAListArg) 1017 if (isa<ParmVarDecl>(VD)) 1018 return true; 1019 } 1020 1021 return false; 1022 } 1023 1024 case Stmt::CallExprClass: { 1025 const CallExpr *CE = cast<CallExpr>(E); 1026 if (const ImplicitCastExpr *ICE 1027 = dyn_cast<ImplicitCastExpr>(CE->getCallee())) { 1028 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) { 1029 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) { 1030 if (const FormatArgAttr *FA = FD->getAttr<FormatArgAttr>()) { 1031 unsigned ArgIndex = FA->getFormatIdx(); 1032 const Expr *Arg = CE->getArg(ArgIndex - 1); 1033 1034 return SemaCheckStringLiteral(Arg, TheCall, HasVAListArg, 1035 format_idx, firstDataArg, isPrintf); 1036 } 1037 } 1038 } 1039 } 1040 1041 return false; 1042 } 1043 case Stmt::ObjCStringLiteralClass: 1044 case Stmt::StringLiteralClass: { 1045 const StringLiteral *StrE = NULL; 1046 1047 if (const ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(E)) 1048 StrE = ObjCFExpr->getString(); 1049 else 1050 StrE = cast<StringLiteral>(E); 1051 1052 if (StrE) { 1053 CheckFormatString(StrE, E, TheCall, HasVAListArg, format_idx, 1054 firstDataArg, isPrintf); 1055 return true; 1056 } 1057 1058 return false; 1059 } 1060 1061 default: 1062 return false; 1063 } 1064} 1065 1066void 1067Sema::CheckNonNullArguments(const NonNullAttr *NonNull, 1068 const CallExpr *TheCall) { 1069 for (NonNullAttr::args_iterator i = NonNull->args_begin(), 1070 e = NonNull->args_end(); 1071 i != e; ++i) { 1072 const Expr *ArgExpr = TheCall->getArg(*i); 1073 if (ArgExpr->isNullPointerConstant(Context, 1074 Expr::NPC_ValueDependentIsNotNull)) 1075 Diag(TheCall->getCallee()->getLocStart(), diag::warn_null_arg) 1076 << ArgExpr->getSourceRange(); 1077 } 1078} 1079 1080/// CheckPrintfScanfArguments - Check calls to printf and scanf (and similar 1081/// functions) for correct use of format strings. 1082void 1083Sema::CheckPrintfScanfArguments(const CallExpr *TheCall, bool HasVAListArg, 1084 unsigned format_idx, unsigned firstDataArg, 1085 bool isPrintf) { 1086 1087 const Expr *Fn = TheCall->getCallee(); 1088 1089 // The way the format attribute works in GCC, the implicit this argument 1090 // of member functions is counted. However, it doesn't appear in our own 1091 // lists, so decrement format_idx in that case. 1092 if (isa<CXXMemberCallExpr>(TheCall)) { 1093 // Catch a format attribute mistakenly referring to the object argument. 1094 if (format_idx == 0) 1095 return; 1096 --format_idx; 1097 if(firstDataArg != 0) 1098 --firstDataArg; 1099 } 1100 1101 // CHECK: printf/scanf-like function is called with no format string. 1102 if (format_idx >= TheCall->getNumArgs()) { 1103 Diag(TheCall->getRParenLoc(), diag::warn_missing_format_string) 1104 << Fn->getSourceRange(); 1105 return; 1106 } 1107 1108 const Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts(); 1109 1110 // CHECK: format string is not a string literal. 1111 // 1112 // Dynamically generated format strings are difficult to 1113 // automatically vet at compile time. Requiring that format strings 1114 // are string literals: (1) permits the checking of format strings by 1115 // the compiler and thereby (2) can practically remove the source of 1116 // many format string exploits. 1117 1118 // Format string can be either ObjC string (e.g. @"%d") or 1119 // C string (e.g. "%d") 1120 // ObjC string uses the same format specifiers as C string, so we can use 1121 // the same format string checking logic for both ObjC and C strings. 1122 if (SemaCheckStringLiteral(OrigFormatExpr, TheCall, HasVAListArg, format_idx, 1123 firstDataArg, isPrintf)) 1124 return; // Literal format string found, check done! 1125 1126 // If there are no arguments specified, warn with -Wformat-security, otherwise 1127 // warn only with -Wformat-nonliteral. 1128 if (TheCall->getNumArgs() == format_idx+1) 1129 Diag(TheCall->getArg(format_idx)->getLocStart(), 1130 diag::warn_format_nonliteral_noargs) 1131 << OrigFormatExpr->getSourceRange(); 1132 else 1133 Diag(TheCall->getArg(format_idx)->getLocStart(), 1134 diag::warn_format_nonliteral) 1135 << OrigFormatExpr->getSourceRange(); 1136} 1137 1138namespace { 1139class CheckFormatHandler : public analyze_format_string::FormatStringHandler { 1140protected: 1141 Sema &S; 1142 const StringLiteral *FExpr; 1143 const Expr *OrigFormatExpr; 1144 const unsigned FirstDataArg; 1145 const unsigned NumDataArgs; 1146 const bool IsObjCLiteral; 1147 const char *Beg; // Start of format string. 1148 const bool HasVAListArg; 1149 const CallExpr *TheCall; 1150 unsigned FormatIdx; 1151 llvm::BitVector CoveredArgs; 1152 bool usesPositionalArgs; 1153 bool atFirstArg; 1154public: 1155 CheckFormatHandler(Sema &s, const StringLiteral *fexpr, 1156 const Expr *origFormatExpr, unsigned firstDataArg, 1157 unsigned numDataArgs, bool isObjCLiteral, 1158 const char *beg, bool hasVAListArg, 1159 const CallExpr *theCall, unsigned formatIdx) 1160 : S(s), FExpr(fexpr), OrigFormatExpr(origFormatExpr), 1161 FirstDataArg(firstDataArg), 1162 NumDataArgs(numDataArgs), 1163 IsObjCLiteral(isObjCLiteral), Beg(beg), 1164 HasVAListArg(hasVAListArg), 1165 TheCall(theCall), FormatIdx(formatIdx), 1166 usesPositionalArgs(false), atFirstArg(true) { 1167 CoveredArgs.resize(numDataArgs); 1168 CoveredArgs.reset(); 1169 } 1170 1171 void DoneProcessing(); 1172 1173 void HandleIncompleteSpecifier(const char *startSpecifier, 1174 unsigned specifierLen); 1175 1176 virtual void HandleInvalidPosition(const char *startSpecifier, 1177 unsigned specifierLen, 1178 analyze_format_string::PositionContext p); 1179 1180 virtual void HandleZeroPosition(const char *startPos, unsigned posLen); 1181 1182 void HandleNullChar(const char *nullCharacter); 1183 1184protected: 1185 bool HandleInvalidConversionSpecifier(unsigned argIndex, SourceLocation Loc, 1186 const char *startSpec, 1187 unsigned specifierLen, 1188 const char *csStart, unsigned csLen); 1189 1190 SourceRange getFormatStringRange(); 1191 CharSourceRange getSpecifierRange(const char *startSpecifier, 1192 unsigned specifierLen); 1193 SourceLocation getLocationOfByte(const char *x); 1194 1195 const Expr *getDataArg(unsigned i) const; 1196 1197 bool CheckNumArgs(const analyze_format_string::FormatSpecifier &FS, 1198 const analyze_format_string::ConversionSpecifier &CS, 1199 const char *startSpecifier, unsigned specifierLen, 1200 unsigned argIndex); 1201}; 1202} 1203 1204SourceRange CheckFormatHandler::getFormatStringRange() { 1205 return OrigFormatExpr->getSourceRange(); 1206} 1207 1208CharSourceRange CheckFormatHandler:: 1209getSpecifierRange(const char *startSpecifier, unsigned specifierLen) { 1210 SourceLocation Start = getLocationOfByte(startSpecifier); 1211 SourceLocation End = getLocationOfByte(startSpecifier + specifierLen - 1); 1212 1213 // Advance the end SourceLocation by one due to half-open ranges. 1214 End = End.getFileLocWithOffset(1); 1215 1216 return CharSourceRange::getCharRange(Start, End); 1217} 1218 1219SourceLocation CheckFormatHandler::getLocationOfByte(const char *x) { 1220 return S.getLocationOfStringLiteralByte(FExpr, x - Beg); 1221} 1222 1223void CheckFormatHandler::HandleIncompleteSpecifier(const char *startSpecifier, 1224 unsigned specifierLen){ 1225 SourceLocation Loc = getLocationOfByte(startSpecifier); 1226 S.Diag(Loc, diag::warn_printf_incomplete_specifier) 1227 << getSpecifierRange(startSpecifier, specifierLen); 1228} 1229 1230void 1231CheckFormatHandler::HandleInvalidPosition(const char *startPos, unsigned posLen, 1232 analyze_format_string::PositionContext p) { 1233 SourceLocation Loc = getLocationOfByte(startPos); 1234 S.Diag(Loc, diag::warn_format_invalid_positional_specifier) 1235 << (unsigned) p << getSpecifierRange(startPos, posLen); 1236} 1237 1238void CheckFormatHandler::HandleZeroPosition(const char *startPos, 1239 unsigned posLen) { 1240 SourceLocation Loc = getLocationOfByte(startPos); 1241 S.Diag(Loc, diag::warn_format_zero_positional_specifier) 1242 << getSpecifierRange(startPos, posLen); 1243} 1244 1245void CheckFormatHandler::HandleNullChar(const char *nullCharacter) { 1246 // The presence of a null character is likely an error. 1247 S.Diag(getLocationOfByte(nullCharacter), 1248 diag::warn_printf_format_string_contains_null_char) 1249 << getFormatStringRange(); 1250} 1251 1252const Expr *CheckFormatHandler::getDataArg(unsigned i) const { 1253 return TheCall->getArg(FirstDataArg + i); 1254} 1255 1256void CheckFormatHandler::DoneProcessing() { 1257 // Does the number of data arguments exceed the number of 1258 // format conversions in the format string? 1259 if (!HasVAListArg) { 1260 // Find any arguments that weren't covered. 1261 CoveredArgs.flip(); 1262 signed notCoveredArg = CoveredArgs.find_first(); 1263 if (notCoveredArg >= 0) { 1264 assert((unsigned)notCoveredArg < NumDataArgs); 1265 S.Diag(getDataArg((unsigned) notCoveredArg)->getLocStart(), 1266 diag::warn_printf_data_arg_not_used) 1267 << getFormatStringRange(); 1268 } 1269 } 1270} 1271 1272bool 1273CheckFormatHandler::HandleInvalidConversionSpecifier(unsigned argIndex, 1274 SourceLocation Loc, 1275 const char *startSpec, 1276 unsigned specifierLen, 1277 const char *csStart, 1278 unsigned csLen) { 1279 1280 bool keepGoing = true; 1281 if (argIndex < NumDataArgs) { 1282 // Consider the argument coverered, even though the specifier doesn't 1283 // make sense. 1284 CoveredArgs.set(argIndex); 1285 } 1286 else { 1287 // If argIndex exceeds the number of data arguments we 1288 // don't issue a warning because that is just a cascade of warnings (and 1289 // they may have intended '%%' anyway). We don't want to continue processing 1290 // the format string after this point, however, as we will like just get 1291 // gibberish when trying to match arguments. 1292 keepGoing = false; 1293 } 1294 1295 S.Diag(Loc, diag::warn_format_invalid_conversion) 1296 << llvm::StringRef(csStart, csLen) 1297 << getSpecifierRange(startSpec, specifierLen); 1298 1299 return keepGoing; 1300} 1301 1302bool 1303CheckFormatHandler::CheckNumArgs( 1304 const analyze_format_string::FormatSpecifier &FS, 1305 const analyze_format_string::ConversionSpecifier &CS, 1306 const char *startSpecifier, unsigned specifierLen, unsigned argIndex) { 1307 1308 if (argIndex >= NumDataArgs) { 1309 if (FS.usesPositionalArg()) { 1310 S.Diag(getLocationOfByte(CS.getStart()), 1311 diag::warn_printf_positional_arg_exceeds_data_args) 1312 << (argIndex+1) << NumDataArgs 1313 << getSpecifierRange(startSpecifier, specifierLen); 1314 } 1315 else { 1316 S.Diag(getLocationOfByte(CS.getStart()), 1317 diag::warn_printf_insufficient_data_args) 1318 << getSpecifierRange(startSpecifier, specifierLen); 1319 } 1320 1321 return false; 1322 } 1323 return true; 1324} 1325 1326//===--- CHECK: Printf format string checking ------------------------------===// 1327 1328namespace { 1329class CheckPrintfHandler : public CheckFormatHandler { 1330public: 1331 CheckPrintfHandler(Sema &s, const StringLiteral *fexpr, 1332 const Expr *origFormatExpr, unsigned firstDataArg, 1333 unsigned numDataArgs, bool isObjCLiteral, 1334 const char *beg, bool hasVAListArg, 1335 const CallExpr *theCall, unsigned formatIdx) 1336 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg, 1337 numDataArgs, isObjCLiteral, beg, hasVAListArg, 1338 theCall, formatIdx) {} 1339 1340 1341 bool HandleInvalidPrintfConversionSpecifier( 1342 const analyze_printf::PrintfSpecifier &FS, 1343 const char *startSpecifier, 1344 unsigned specifierLen); 1345 1346 bool HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier &FS, 1347 const char *startSpecifier, 1348 unsigned specifierLen); 1349 1350 bool HandleAmount(const analyze_format_string::OptionalAmount &Amt, unsigned k, 1351 const char *startSpecifier, unsigned specifierLen); 1352 void HandleInvalidAmount(const analyze_printf::PrintfSpecifier &FS, 1353 const analyze_printf::OptionalAmount &Amt, 1354 unsigned type, 1355 const char *startSpecifier, unsigned specifierLen); 1356 void HandleFlag(const analyze_printf::PrintfSpecifier &FS, 1357 const analyze_printf::OptionalFlag &flag, 1358 const char *startSpecifier, unsigned specifierLen); 1359 void HandleIgnoredFlag(const analyze_printf::PrintfSpecifier &FS, 1360 const analyze_printf::OptionalFlag &ignoredFlag, 1361 const analyze_printf::OptionalFlag &flag, 1362 const char *startSpecifier, unsigned specifierLen); 1363}; 1364} 1365 1366bool CheckPrintfHandler::HandleInvalidPrintfConversionSpecifier( 1367 const analyze_printf::PrintfSpecifier &FS, 1368 const char *startSpecifier, 1369 unsigned specifierLen) { 1370 const analyze_printf::PrintfConversionSpecifier &CS = 1371 FS.getConversionSpecifier(); 1372 1373 return HandleInvalidConversionSpecifier(FS.getArgIndex(), 1374 getLocationOfByte(CS.getStart()), 1375 startSpecifier, specifierLen, 1376 CS.getStart(), CS.getLength()); 1377} 1378 1379bool CheckPrintfHandler::HandleAmount( 1380 const analyze_format_string::OptionalAmount &Amt, 1381 unsigned k, const char *startSpecifier, 1382 unsigned specifierLen) { 1383 1384 if (Amt.hasDataArgument()) { 1385 if (!HasVAListArg) { 1386 unsigned argIndex = Amt.getArgIndex(); 1387 if (argIndex >= NumDataArgs) { 1388 S.Diag(getLocationOfByte(Amt.getStart()), 1389 diag::warn_printf_asterisk_missing_arg) 1390 << k << getSpecifierRange(startSpecifier, specifierLen); 1391 // Don't do any more checking. We will just emit 1392 // spurious errors. 1393 return false; 1394 } 1395 1396 // Type check the data argument. It should be an 'int'. 1397 // Although not in conformance with C99, we also allow the argument to be 1398 // an 'unsigned int' as that is a reasonably safe case. GCC also 1399 // doesn't emit a warning for that case. 1400 CoveredArgs.set(argIndex); 1401 const Expr *Arg = getDataArg(argIndex); 1402 QualType T = Arg->getType(); 1403 1404 const analyze_printf::ArgTypeResult &ATR = Amt.getArgType(S.Context); 1405 assert(ATR.isValid()); 1406 1407 if (!ATR.matchesType(S.Context, T)) { 1408 S.Diag(getLocationOfByte(Amt.getStart()), 1409 diag::warn_printf_asterisk_wrong_type) 1410 << k 1411 << ATR.getRepresentativeType(S.Context) << T 1412 << getSpecifierRange(startSpecifier, specifierLen) 1413 << Arg->getSourceRange(); 1414 // Don't do any more checking. We will just emit 1415 // spurious errors. 1416 return false; 1417 } 1418 } 1419 } 1420 return true; 1421} 1422 1423void CheckPrintfHandler::HandleInvalidAmount( 1424 const analyze_printf::PrintfSpecifier &FS, 1425 const analyze_printf::OptionalAmount &Amt, 1426 unsigned type, 1427 const char *startSpecifier, 1428 unsigned specifierLen) { 1429 const analyze_printf::PrintfConversionSpecifier &CS = 1430 FS.getConversionSpecifier(); 1431 switch (Amt.getHowSpecified()) { 1432 case analyze_printf::OptionalAmount::Constant: 1433 S.Diag(getLocationOfByte(Amt.getStart()), 1434 diag::warn_printf_nonsensical_optional_amount) 1435 << type 1436 << CS.toString() 1437 << getSpecifierRange(startSpecifier, specifierLen) 1438 << FixItHint::CreateRemoval(getSpecifierRange(Amt.getStart(), 1439 Amt.getConstantLength())); 1440 break; 1441 1442 default: 1443 S.Diag(getLocationOfByte(Amt.getStart()), 1444 diag::warn_printf_nonsensical_optional_amount) 1445 << type 1446 << CS.toString() 1447 << getSpecifierRange(startSpecifier, specifierLen); 1448 break; 1449 } 1450} 1451 1452void CheckPrintfHandler::HandleFlag(const analyze_printf::PrintfSpecifier &FS, 1453 const analyze_printf::OptionalFlag &flag, 1454 const char *startSpecifier, 1455 unsigned specifierLen) { 1456 // Warn about pointless flag with a fixit removal. 1457 const analyze_printf::PrintfConversionSpecifier &CS = 1458 FS.getConversionSpecifier(); 1459 S.Diag(getLocationOfByte(flag.getPosition()), 1460 diag::warn_printf_nonsensical_flag) 1461 << flag.toString() << CS.toString() 1462 << getSpecifierRange(startSpecifier, specifierLen) 1463 << FixItHint::CreateRemoval(getSpecifierRange(flag.getPosition(), 1)); 1464} 1465 1466void CheckPrintfHandler::HandleIgnoredFlag( 1467 const analyze_printf::PrintfSpecifier &FS, 1468 const analyze_printf::OptionalFlag &ignoredFlag, 1469 const analyze_printf::OptionalFlag &flag, 1470 const char *startSpecifier, 1471 unsigned specifierLen) { 1472 // Warn about ignored flag with a fixit removal. 1473 S.Diag(getLocationOfByte(ignoredFlag.getPosition()), 1474 diag::warn_printf_ignored_flag) 1475 << ignoredFlag.toString() << flag.toString() 1476 << getSpecifierRange(startSpecifier, specifierLen) 1477 << FixItHint::CreateRemoval(getSpecifierRange( 1478 ignoredFlag.getPosition(), 1)); 1479} 1480 1481bool 1482CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier 1483 &FS, 1484 const char *startSpecifier, 1485 unsigned specifierLen) { 1486 1487 using namespace analyze_format_string; 1488 using namespace analyze_printf; 1489 const PrintfConversionSpecifier &CS = FS.getConversionSpecifier(); 1490 1491 if (FS.consumesDataArgument()) { 1492 if (atFirstArg) { 1493 atFirstArg = false; 1494 usesPositionalArgs = FS.usesPositionalArg(); 1495 } 1496 else if (usesPositionalArgs != FS.usesPositionalArg()) { 1497 // Cannot mix-and-match positional and non-positional arguments. 1498 S.Diag(getLocationOfByte(CS.getStart()), 1499 diag::warn_format_mix_positional_nonpositional_args) 1500 << getSpecifierRange(startSpecifier, specifierLen); 1501 return false; 1502 } 1503 } 1504 1505 // First check if the field width, precision, and conversion specifier 1506 // have matching data arguments. 1507 if (!HandleAmount(FS.getFieldWidth(), /* field width */ 0, 1508 startSpecifier, specifierLen)) { 1509 return false; 1510 } 1511 1512 if (!HandleAmount(FS.getPrecision(), /* precision */ 1, 1513 startSpecifier, specifierLen)) { 1514 return false; 1515 } 1516 1517 if (!CS.consumesDataArgument()) { 1518 // FIXME: Technically specifying a precision or field width here 1519 // makes no sense. Worth issuing a warning at some point. 1520 return true; 1521 } 1522 1523 // Consume the argument. 1524 unsigned argIndex = FS.getArgIndex(); 1525 if (argIndex < NumDataArgs) { 1526 // The check to see if the argIndex is valid will come later. 1527 // We set the bit here because we may exit early from this 1528 // function if we encounter some other error. 1529 CoveredArgs.set(argIndex); 1530 } 1531 1532 // Check for using an Objective-C specific conversion specifier 1533 // in a non-ObjC literal. 1534 if (!IsObjCLiteral && CS.isObjCArg()) { 1535 return HandleInvalidPrintfConversionSpecifier(FS, startSpecifier, 1536 specifierLen); 1537 } 1538 1539 // Check for invalid use of field width 1540 if (!FS.hasValidFieldWidth()) { 1541 HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 0, 1542 startSpecifier, specifierLen); 1543 } 1544 1545 // Check for invalid use of precision 1546 if (!FS.hasValidPrecision()) { 1547 HandleInvalidAmount(FS, FS.getPrecision(), /* precision */ 1, 1548 startSpecifier, specifierLen); 1549 } 1550 1551 // Check each flag does not conflict with any other component. 1552 if (!FS.hasValidLeadingZeros()) 1553 HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen); 1554 if (!FS.hasValidPlusPrefix()) 1555 HandleFlag(FS, FS.hasPlusPrefix(), startSpecifier, specifierLen); 1556 if (!FS.hasValidSpacePrefix()) 1557 HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen); 1558 if (!FS.hasValidAlternativeForm()) 1559 HandleFlag(FS, FS.hasAlternativeForm(), startSpecifier, specifierLen); 1560 if (!FS.hasValidLeftJustified()) 1561 HandleFlag(FS, FS.isLeftJustified(), startSpecifier, specifierLen); 1562 1563 // Check that flags are not ignored by another flag 1564 if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+' 1565 HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(), 1566 startSpecifier, specifierLen); 1567 if (FS.hasLeadingZeros() && FS.isLeftJustified()) // '0' ignored by '-' 1568 HandleIgnoredFlag(FS, FS.hasLeadingZeros(), FS.isLeftJustified(), 1569 startSpecifier, specifierLen); 1570 1571 // Check the length modifier is valid with the given conversion specifier. 1572 const LengthModifier &LM = FS.getLengthModifier(); 1573 if (!FS.hasValidLengthModifier()) 1574 S.Diag(getLocationOfByte(LM.getStart()), 1575 diag::warn_format_nonsensical_length) 1576 << LM.toString() << CS.toString() 1577 << getSpecifierRange(startSpecifier, specifierLen) 1578 << FixItHint::CreateRemoval(getSpecifierRange(LM.getStart(), 1579 LM.getLength())); 1580 1581 // Are we using '%n'? 1582 if (CS.getKind() == ConversionSpecifier::nArg) { 1583 // Issue a warning about this being a possible security issue. 1584 S.Diag(getLocationOfByte(CS.getStart()), diag::warn_printf_write_back) 1585 << getSpecifierRange(startSpecifier, specifierLen); 1586 // Continue checking the other format specifiers. 1587 return true; 1588 } 1589 1590 // The remaining checks depend on the data arguments. 1591 if (HasVAListArg) 1592 return true; 1593 1594 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex)) 1595 return false; 1596 1597 // Now type check the data expression that matches the 1598 // format specifier. 1599 const Expr *Ex = getDataArg(argIndex); 1600 const analyze_printf::ArgTypeResult &ATR = FS.getArgType(S.Context); 1601 if (ATR.isValid() && !ATR.matchesType(S.Context, Ex->getType())) { 1602 // Check if we didn't match because of an implicit cast from a 'char' 1603 // or 'short' to an 'int'. This is done because printf is a varargs 1604 // function. 1605 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Ex)) 1606 if (ICE->getType() == S.Context.IntTy) 1607 if (ATR.matchesType(S.Context, ICE->getSubExpr()->getType())) 1608 return true; 1609 1610 // We may be able to offer a FixItHint if it is a supported type. 1611 PrintfSpecifier fixedFS = FS; 1612 bool success = fixedFS.fixType(Ex->getType()); 1613 1614 if (success) { 1615 // Get the fix string from the fixed format specifier 1616 llvm::SmallString<128> buf; 1617 llvm::raw_svector_ostream os(buf); 1618 fixedFS.toString(os); 1619 1620 // FIXME: getRepresentativeType() perhaps should return a string 1621 // instead of a QualType to better handle when the representative 1622 // type is 'wint_t' (which is defined in the system headers). 1623 S.Diag(getLocationOfByte(CS.getStart()), 1624 diag::warn_printf_conversion_argument_type_mismatch) 1625 << ATR.getRepresentativeType(S.Context) << Ex->getType() 1626 << getSpecifierRange(startSpecifier, specifierLen) 1627 << Ex->getSourceRange() 1628 << FixItHint::CreateReplacement( 1629 getSpecifierRange(startSpecifier, specifierLen), 1630 os.str()); 1631 } 1632 else { 1633 S.Diag(getLocationOfByte(CS.getStart()), 1634 diag::warn_printf_conversion_argument_type_mismatch) 1635 << ATR.getRepresentativeType(S.Context) << Ex->getType() 1636 << getSpecifierRange(startSpecifier, specifierLen) 1637 << Ex->getSourceRange(); 1638 } 1639 } 1640 1641 return true; 1642} 1643 1644//===--- CHECK: Scanf format string checking ------------------------------===// 1645 1646namespace { 1647class CheckScanfHandler : public CheckFormatHandler { 1648public: 1649 CheckScanfHandler(Sema &s, const StringLiteral *fexpr, 1650 const Expr *origFormatExpr, unsigned firstDataArg, 1651 unsigned numDataArgs, bool isObjCLiteral, 1652 const char *beg, bool hasVAListArg, 1653 const CallExpr *theCall, unsigned formatIdx) 1654 : CheckFormatHandler(s, fexpr, origFormatExpr, firstDataArg, 1655 numDataArgs, isObjCLiteral, beg, hasVAListArg, 1656 theCall, formatIdx) {} 1657 1658 bool HandleScanfSpecifier(const analyze_scanf::ScanfSpecifier &FS, 1659 const char *startSpecifier, 1660 unsigned specifierLen); 1661 1662 bool HandleInvalidScanfConversionSpecifier( 1663 const analyze_scanf::ScanfSpecifier &FS, 1664 const char *startSpecifier, 1665 unsigned specifierLen); 1666 1667 void HandleIncompleteScanList(const char *start, const char *end); 1668}; 1669} 1670 1671void CheckScanfHandler::HandleIncompleteScanList(const char *start, 1672 const char *end) { 1673 S.Diag(getLocationOfByte(end), diag::warn_scanf_scanlist_incomplete) 1674 << getSpecifierRange(start, end - start); 1675} 1676 1677bool CheckScanfHandler::HandleInvalidScanfConversionSpecifier( 1678 const analyze_scanf::ScanfSpecifier &FS, 1679 const char *startSpecifier, 1680 unsigned specifierLen) { 1681 1682 const analyze_scanf::ScanfConversionSpecifier &CS = 1683 FS.getConversionSpecifier(); 1684 1685 return HandleInvalidConversionSpecifier(FS.getArgIndex(), 1686 getLocationOfByte(CS.getStart()), 1687 startSpecifier, specifierLen, 1688 CS.getStart(), CS.getLength()); 1689} 1690 1691bool CheckScanfHandler::HandleScanfSpecifier( 1692 const analyze_scanf::ScanfSpecifier &FS, 1693 const char *startSpecifier, 1694 unsigned specifierLen) { 1695 1696 using namespace analyze_scanf; 1697 using namespace analyze_format_string; 1698 1699 const ScanfConversionSpecifier &CS = FS.getConversionSpecifier(); 1700 1701 // Handle case where '%' and '*' don't consume an argument. These shouldn't 1702 // be used to decide if we are using positional arguments consistently. 1703 if (FS.consumesDataArgument()) { 1704 if (atFirstArg) { 1705 atFirstArg = false; 1706 usesPositionalArgs = FS.usesPositionalArg(); 1707 } 1708 else if (usesPositionalArgs != FS.usesPositionalArg()) { 1709 // Cannot mix-and-match positional and non-positional arguments. 1710 S.Diag(getLocationOfByte(CS.getStart()), 1711 diag::warn_format_mix_positional_nonpositional_args) 1712 << getSpecifierRange(startSpecifier, specifierLen); 1713 return false; 1714 } 1715 } 1716 1717 // Check if the field with is non-zero. 1718 const OptionalAmount &Amt = FS.getFieldWidth(); 1719 if (Amt.getHowSpecified() == OptionalAmount::Constant) { 1720 if (Amt.getConstantAmount() == 0) { 1721 const CharSourceRange &R = getSpecifierRange(Amt.getStart(), 1722 Amt.getConstantLength()); 1723 S.Diag(getLocationOfByte(Amt.getStart()), 1724 diag::warn_scanf_nonzero_width) 1725 << R << FixItHint::CreateRemoval(R); 1726 } 1727 } 1728 1729 if (!FS.consumesDataArgument()) { 1730 // FIXME: Technically specifying a precision or field width here 1731 // makes no sense. Worth issuing a warning at some point. 1732 return true; 1733 } 1734 1735 // Consume the argument. 1736 unsigned argIndex = FS.getArgIndex(); 1737 if (argIndex < NumDataArgs) { 1738 // The check to see if the argIndex is valid will come later. 1739 // We set the bit here because we may exit early from this 1740 // function if we encounter some other error. 1741 CoveredArgs.set(argIndex); 1742 } 1743 1744 // Check the length modifier is valid with the given conversion specifier. 1745 const LengthModifier &LM = FS.getLengthModifier(); 1746 if (!FS.hasValidLengthModifier()) { 1747 S.Diag(getLocationOfByte(LM.getStart()), 1748 diag::warn_format_nonsensical_length) 1749 << LM.toString() << CS.toString() 1750 << getSpecifierRange(startSpecifier, specifierLen) 1751 << FixItHint::CreateRemoval(getSpecifierRange(LM.getStart(), 1752 LM.getLength())); 1753 } 1754 1755 // The remaining checks depend on the data arguments. 1756 if (HasVAListArg) 1757 return true; 1758 1759 if (!CheckNumArgs(FS, CS, startSpecifier, specifierLen, argIndex)) 1760 return false; 1761 1762 // FIXME: Check that the argument type matches the format specifier. 1763 1764 return true; 1765} 1766 1767void Sema::CheckFormatString(const StringLiteral *FExpr, 1768 const Expr *OrigFormatExpr, 1769 const CallExpr *TheCall, bool HasVAListArg, 1770 unsigned format_idx, unsigned firstDataArg, 1771 bool isPrintf) { 1772 1773 // CHECK: is the format string a wide literal? 1774 if (FExpr->isWide()) { 1775 Diag(FExpr->getLocStart(), 1776 diag::warn_format_string_is_wide_literal) 1777 << OrigFormatExpr->getSourceRange(); 1778 return; 1779 } 1780 1781 // Str - The format string. NOTE: this is NOT null-terminated! 1782 llvm::StringRef StrRef = FExpr->getString(); 1783 const char *Str = StrRef.data(); 1784 unsigned StrLen = StrRef.size(); 1785 1786 // CHECK: empty format string? 1787 if (StrLen == 0) { 1788 Diag(FExpr->getLocStart(), diag::warn_empty_format_string) 1789 << OrigFormatExpr->getSourceRange(); 1790 return; 1791 } 1792 1793 if (isPrintf) { 1794 CheckPrintfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg, 1795 TheCall->getNumArgs() - firstDataArg, 1796 isa<ObjCStringLiteral>(OrigFormatExpr), Str, 1797 HasVAListArg, TheCall, format_idx); 1798 1799 if (!analyze_format_string::ParsePrintfString(H, Str, Str + StrLen)) 1800 H.DoneProcessing(); 1801 } 1802 else { 1803 CheckScanfHandler H(*this, FExpr, OrigFormatExpr, firstDataArg, 1804 TheCall->getNumArgs() - firstDataArg, 1805 isa<ObjCStringLiteral>(OrigFormatExpr), Str, 1806 HasVAListArg, TheCall, format_idx); 1807 1808 if (!analyze_format_string::ParseScanfString(H, Str, Str + StrLen)) 1809 H.DoneProcessing(); 1810 } 1811} 1812 1813//===--- CHECK: Return Address of Stack Variable --------------------------===// 1814 1815static DeclRefExpr* EvalVal(Expr *E); 1816static DeclRefExpr* EvalAddr(Expr* E); 1817 1818/// CheckReturnStackAddr - Check if a return statement returns the address 1819/// of a stack variable. 1820void 1821Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType, 1822 SourceLocation ReturnLoc) { 1823 1824 // Perform checking for returned stack addresses. 1825 if (lhsType->isPointerType() || lhsType->isBlockPointerType()) { 1826 if (DeclRefExpr *DR = EvalAddr(RetValExp)) 1827 Diag(DR->getLocStart(), diag::warn_ret_stack_addr) 1828 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange(); 1829 1830 // Skip over implicit cast expressions when checking for block expressions. 1831 RetValExp = RetValExp->IgnoreParenCasts(); 1832 1833 if (BlockExpr *C = dyn_cast<BlockExpr>(RetValExp)) 1834 if (C->hasBlockDeclRefExprs()) 1835 Diag(C->getLocStart(), diag::err_ret_local_block) 1836 << C->getSourceRange(); 1837 1838 if (AddrLabelExpr *ALE = dyn_cast<AddrLabelExpr>(RetValExp)) 1839 Diag(ALE->getLocStart(), diag::warn_ret_addr_label) 1840 << ALE->getSourceRange(); 1841 1842 } else if (lhsType->isReferenceType()) { 1843 // Perform checking for stack values returned by reference. 1844 // Check for a reference to the stack 1845 if (DeclRefExpr *DR = EvalVal(RetValExp)) 1846 Diag(DR->getLocStart(), diag::warn_ret_stack_ref) 1847 << DR->getDecl()->getDeclName() << RetValExp->getSourceRange(); 1848 } 1849} 1850 1851/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that 1852/// check if the expression in a return statement evaluates to an address 1853/// to a location on the stack. The recursion is used to traverse the 1854/// AST of the return expression, with recursion backtracking when we 1855/// encounter a subexpression that (1) clearly does not lead to the address 1856/// of a stack variable or (2) is something we cannot determine leads to 1857/// the address of a stack variable based on such local checking. 1858/// 1859/// EvalAddr processes expressions that are pointers that are used as 1860/// references (and not L-values). EvalVal handles all other values. 1861/// At the base case of the recursion is a check for a DeclRefExpr* in 1862/// the refers to a stack variable. 1863/// 1864/// This implementation handles: 1865/// 1866/// * pointer-to-pointer casts 1867/// * implicit conversions from array references to pointers 1868/// * taking the address of fields 1869/// * arbitrary interplay between "&" and "*" operators 1870/// * pointer arithmetic from an address of a stack variable 1871/// * taking the address of an array element where the array is on the stack 1872static DeclRefExpr* EvalAddr(Expr *E) { 1873 // We should only be called for evaluating pointer expressions. 1874 assert((E->getType()->isAnyPointerType() || 1875 E->getType()->isBlockPointerType() || 1876 E->getType()->isObjCQualifiedIdType()) && 1877 "EvalAddr only works on pointers"); 1878 1879 // Our "symbolic interpreter" is just a dispatch off the currently 1880 // viewed AST node. We then recursively traverse the AST by calling 1881 // EvalAddr and EvalVal appropriately. 1882 switch (E->getStmtClass()) { 1883 case Stmt::ParenExprClass: 1884 // Ignore parentheses. 1885 return EvalAddr(cast<ParenExpr>(E)->getSubExpr()); 1886 1887 case Stmt::UnaryOperatorClass: { 1888 // The only unary operator that make sense to handle here 1889 // is AddrOf. All others don't make sense as pointers. 1890 UnaryOperator *U = cast<UnaryOperator>(E); 1891 1892 if (U->getOpcode() == UO_AddrOf) 1893 return EvalVal(U->getSubExpr()); 1894 else 1895 return NULL; 1896 } 1897 1898 case Stmt::BinaryOperatorClass: { 1899 // Handle pointer arithmetic. All other binary operators are not valid 1900 // in this context. 1901 BinaryOperator *B = cast<BinaryOperator>(E); 1902 BinaryOperatorKind op = B->getOpcode(); 1903 1904 if (op != BO_Add && op != BO_Sub) 1905 return NULL; 1906 1907 Expr *Base = B->getLHS(); 1908 1909 // Determine which argument is the real pointer base. It could be 1910 // the RHS argument instead of the LHS. 1911 if (!Base->getType()->isPointerType()) Base = B->getRHS(); 1912 1913 assert (Base->getType()->isPointerType()); 1914 return EvalAddr(Base); 1915 } 1916 1917 // For conditional operators we need to see if either the LHS or RHS are 1918 // valid DeclRefExpr*s. If one of them is valid, we return it. 1919 case Stmt::ConditionalOperatorClass: { 1920 ConditionalOperator *C = cast<ConditionalOperator>(E); 1921 1922 // Handle the GNU extension for missing LHS. 1923 if (Expr *lhsExpr = C->getLHS()) 1924 if (DeclRefExpr* LHS = EvalAddr(lhsExpr)) 1925 return LHS; 1926 1927 return EvalAddr(C->getRHS()); 1928 } 1929 1930 // For casts, we need to handle conversions from arrays to 1931 // pointer values, and pointer-to-pointer conversions. 1932 case Stmt::ImplicitCastExprClass: 1933 case Stmt::CStyleCastExprClass: 1934 case Stmt::CXXFunctionalCastExprClass: { 1935 Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 1936 QualType T = SubExpr->getType(); 1937 1938 if (SubExpr->getType()->isPointerType() || 1939 SubExpr->getType()->isBlockPointerType() || 1940 SubExpr->getType()->isObjCQualifiedIdType()) 1941 return EvalAddr(SubExpr); 1942 else if (T->isArrayType()) 1943 return EvalVal(SubExpr); 1944 else 1945 return 0; 1946 } 1947 1948 // C++ casts. For dynamic casts, static casts, and const casts, we 1949 // are always converting from a pointer-to-pointer, so we just blow 1950 // through the cast. In the case the dynamic cast doesn't fail (and 1951 // return NULL), we take the conservative route and report cases 1952 // where we return the address of a stack variable. For Reinterpre 1953 // FIXME: The comment about is wrong; we're not always converting 1954 // from pointer to pointer. I'm guessing that this code should also 1955 // handle references to objects. 1956 case Stmt::CXXStaticCastExprClass: 1957 case Stmt::CXXDynamicCastExprClass: 1958 case Stmt::CXXConstCastExprClass: 1959 case Stmt::CXXReinterpretCastExprClass: { 1960 Expr *S = cast<CXXNamedCastExpr>(E)->getSubExpr(); 1961 if (S->getType()->isPointerType() || S->getType()->isBlockPointerType()) 1962 return EvalAddr(S); 1963 else 1964 return NULL; 1965 } 1966 1967 // Everything else: we simply don't reason about them. 1968 default: 1969 return NULL; 1970 } 1971} 1972 1973 1974/// EvalVal - This function is complements EvalAddr in the mutual recursion. 1975/// See the comments for EvalAddr for more details. 1976static DeclRefExpr* EvalVal(Expr *E) { 1977do { 1978 // We should only be called for evaluating non-pointer expressions, or 1979 // expressions with a pointer type that are not used as references but instead 1980 // are l-values (e.g., DeclRefExpr with a pointer type). 1981 1982 // Our "symbolic interpreter" is just a dispatch off the currently 1983 // viewed AST node. We then recursively traverse the AST by calling 1984 // EvalAddr and EvalVal appropriately. 1985 switch (E->getStmtClass()) { 1986 case Stmt::ImplicitCastExprClass: { 1987 ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E); 1988 if (IE->getValueKind() == VK_LValue) { 1989 E = IE->getSubExpr(); 1990 continue; 1991 } 1992 return NULL; 1993 } 1994 1995 case Stmt::DeclRefExprClass: { 1996 // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking 1997 // at code that refers to a variable's name. We check if it has local 1998 // storage within the function, and if so, return the expression. 1999 DeclRefExpr *DR = cast<DeclRefExpr>(E); 2000 2001 if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) 2002 if (V->hasLocalStorage() && !V->getType()->isReferenceType()) return DR; 2003 2004 return NULL; 2005 } 2006 2007 case Stmt::ParenExprClass: { 2008 // Ignore parentheses. 2009 E = cast<ParenExpr>(E)->getSubExpr(); 2010 continue; 2011 } 2012 2013 case Stmt::UnaryOperatorClass: { 2014 // The only unary operator that make sense to handle here 2015 // is Deref. All others don't resolve to a "name." This includes 2016 // handling all sorts of rvalues passed to a unary operator. 2017 UnaryOperator *U = cast<UnaryOperator>(E); 2018 2019 if (U->getOpcode() == UO_Deref) 2020 return EvalAddr(U->getSubExpr()); 2021 2022 return NULL; 2023 } 2024 2025 case Stmt::ArraySubscriptExprClass: { 2026 // Array subscripts are potential references to data on the stack. We 2027 // retrieve the DeclRefExpr* for the array variable if it indeed 2028 // has local storage. 2029 return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase()); 2030 } 2031 2032 case Stmt::ConditionalOperatorClass: { 2033 // For conditional operators we need to see if either the LHS or RHS are 2034 // non-NULL DeclRefExpr's. If one is non-NULL, we return it. 2035 ConditionalOperator *C = cast<ConditionalOperator>(E); 2036 2037 // Handle the GNU extension for missing LHS. 2038 if (Expr *lhsExpr = C->getLHS()) 2039 if (DeclRefExpr *LHS = EvalVal(lhsExpr)) 2040 return LHS; 2041 2042 return EvalVal(C->getRHS()); 2043 } 2044 2045 // Accesses to members are potential references to data on the stack. 2046 case Stmt::MemberExprClass: { 2047 MemberExpr *M = cast<MemberExpr>(E); 2048 2049 // Check for indirect access. We only want direct field accesses. 2050 if (M->isArrow()) 2051 return NULL; 2052 2053 // Check whether the member type is itself a reference, in which case 2054 // we're not going to refer to the member, but to what the member refers to. 2055 if (M->getMemberDecl()->getType()->isReferenceType()) 2056 return NULL; 2057 2058 return EvalVal(M->getBase()); 2059 } 2060 2061 // Everything else: we simply don't reason about them. 2062 default: 2063 return NULL; 2064 } 2065} while (true); 2066} 2067 2068//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===// 2069 2070/// Check for comparisons of floating point operands using != and ==. 2071/// Issue a warning if these are no self-comparisons, as they are not likely 2072/// to do what the programmer intended. 2073void Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) { 2074 bool EmitWarning = true; 2075 2076 Expr* LeftExprSansParen = lex->IgnoreParens(); 2077 Expr* RightExprSansParen = rex->IgnoreParens(); 2078 2079 // Special case: check for x == x (which is OK). 2080 // Do not emit warnings for such cases. 2081 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen)) 2082 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen)) 2083 if (DRL->getDecl() == DRR->getDecl()) 2084 EmitWarning = false; 2085 2086 2087 // Special case: check for comparisons against literals that can be exactly 2088 // represented by APFloat. In such cases, do not emit a warning. This 2089 // is a heuristic: often comparison against such literals are used to 2090 // detect if a value in a variable has not changed. This clearly can 2091 // lead to false negatives. 2092 if (EmitWarning) { 2093 if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) { 2094 if (FLL->isExact()) 2095 EmitWarning = false; 2096 } else 2097 if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){ 2098 if (FLR->isExact()) 2099 EmitWarning = false; 2100 } 2101 } 2102 2103 // Check for comparisons with builtin types. 2104 if (EmitWarning) 2105 if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen)) 2106 if (CL->isBuiltinCall(Context)) 2107 EmitWarning = false; 2108 2109 if (EmitWarning) 2110 if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen)) 2111 if (CR->isBuiltinCall(Context)) 2112 EmitWarning = false; 2113 2114 // Emit the diagnostic. 2115 if (EmitWarning) 2116 Diag(loc, diag::warn_floatingpoint_eq) 2117 << lex->getSourceRange() << rex->getSourceRange(); 2118} 2119 2120//===--- CHECK: Integer mixed-sign comparisons (-Wsign-compare) --------===// 2121//===--- CHECK: Lossy implicit conversions (-Wconversion) --------------===// 2122 2123namespace { 2124 2125/// Structure recording the 'active' range of an integer-valued 2126/// expression. 2127struct IntRange { 2128 /// The number of bits active in the int. 2129 unsigned Width; 2130 2131 /// True if the int is known not to have negative values. 2132 bool NonNegative; 2133 2134 IntRange(unsigned Width, bool NonNegative) 2135 : Width(Width), NonNegative(NonNegative) 2136 {} 2137 2138 // Returns the range of the bool type. 2139 static IntRange forBoolType() { 2140 return IntRange(1, true); 2141 } 2142 2143 // Returns the range of an integral type. 2144 static IntRange forType(ASTContext &C, QualType T) { 2145 return forCanonicalType(C, T->getCanonicalTypeInternal().getTypePtr()); 2146 } 2147 2148 // Returns the range of an integeral type based on its canonical 2149 // representation. 2150 static IntRange forCanonicalType(ASTContext &C, const Type *T) { 2151 assert(T->isCanonicalUnqualified()); 2152 2153 if (const VectorType *VT = dyn_cast<VectorType>(T)) 2154 T = VT->getElementType().getTypePtr(); 2155 if (const ComplexType *CT = dyn_cast<ComplexType>(T)) 2156 T = CT->getElementType().getTypePtr(); 2157 2158 if (const EnumType *ET = dyn_cast<EnumType>(T)) { 2159 EnumDecl *Enum = ET->getDecl(); 2160 unsigned NumPositive = Enum->getNumPositiveBits(); 2161 unsigned NumNegative = Enum->getNumNegativeBits(); 2162 2163 return IntRange(std::max(NumPositive, NumNegative), NumNegative == 0); 2164 } 2165 2166 const BuiltinType *BT = cast<BuiltinType>(T); 2167 assert(BT->isInteger()); 2168 2169 return IntRange(C.getIntWidth(QualType(T, 0)), BT->isUnsignedInteger()); 2170 } 2171 2172 // Returns the supremum of two ranges: i.e. their conservative merge. 2173 static IntRange join(IntRange L, IntRange R) { 2174 return IntRange(std::max(L.Width, R.Width), 2175 L.NonNegative && R.NonNegative); 2176 } 2177 2178 // Returns the infinum of two ranges: i.e. their aggressive merge. 2179 static IntRange meet(IntRange L, IntRange R) { 2180 return IntRange(std::min(L.Width, R.Width), 2181 L.NonNegative || R.NonNegative); 2182 } 2183}; 2184 2185IntRange GetValueRange(ASTContext &C, llvm::APSInt &value, unsigned MaxWidth) { 2186 if (value.isSigned() && value.isNegative()) 2187 return IntRange(value.getMinSignedBits(), false); 2188 2189 if (value.getBitWidth() > MaxWidth) 2190 value.trunc(MaxWidth); 2191 2192 // isNonNegative() just checks the sign bit without considering 2193 // signedness. 2194 return IntRange(value.getActiveBits(), true); 2195} 2196 2197IntRange GetValueRange(ASTContext &C, APValue &result, QualType Ty, 2198 unsigned MaxWidth) { 2199 if (result.isInt()) 2200 return GetValueRange(C, result.getInt(), MaxWidth); 2201 2202 if (result.isVector()) { 2203 IntRange R = GetValueRange(C, result.getVectorElt(0), Ty, MaxWidth); 2204 for (unsigned i = 1, e = result.getVectorLength(); i != e; ++i) { 2205 IntRange El = GetValueRange(C, result.getVectorElt(i), Ty, MaxWidth); 2206 R = IntRange::join(R, El); 2207 } 2208 return R; 2209 } 2210 2211 if (result.isComplexInt()) { 2212 IntRange R = GetValueRange(C, result.getComplexIntReal(), MaxWidth); 2213 IntRange I = GetValueRange(C, result.getComplexIntImag(), MaxWidth); 2214 return IntRange::join(R, I); 2215 } 2216 2217 // This can happen with lossless casts to intptr_t of "based" lvalues. 2218 // Assume it might use arbitrary bits. 2219 // FIXME: The only reason we need to pass the type in here is to get 2220 // the sign right on this one case. It would be nice if APValue 2221 // preserved this. 2222 assert(result.isLValue()); 2223 return IntRange(MaxWidth, Ty->isUnsignedIntegerType()); 2224} 2225 2226/// Pseudo-evaluate the given integer expression, estimating the 2227/// range of values it might take. 2228/// 2229/// \param MaxWidth - the width to which the value will be truncated 2230IntRange GetExprRange(ASTContext &C, Expr *E, unsigned MaxWidth) { 2231 E = E->IgnoreParens(); 2232 2233 // Try a full evaluation first. 2234 Expr::EvalResult result; 2235 if (E->Evaluate(result, C)) 2236 return GetValueRange(C, result.Val, E->getType(), MaxWidth); 2237 2238 // I think we only want to look through implicit casts here; if the 2239 // user has an explicit widening cast, we should treat the value as 2240 // being of the new, wider type. 2241 if (ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E)) { 2242 if (CE->getCastKind() == CK_NoOp) 2243 return GetExprRange(C, CE->getSubExpr(), MaxWidth); 2244 2245 IntRange OutputTypeRange = IntRange::forType(C, CE->getType()); 2246 2247 bool isIntegerCast = (CE->getCastKind() == CK_IntegralCast); 2248 if (!isIntegerCast && CE->getCastKind() == CK_Unknown) 2249 isIntegerCast = CE->getSubExpr()->getType()->isIntegerType(); 2250 2251 // Assume that non-integer casts can span the full range of the type. 2252 if (!isIntegerCast) 2253 return OutputTypeRange; 2254 2255 IntRange SubRange 2256 = GetExprRange(C, CE->getSubExpr(), 2257 std::min(MaxWidth, OutputTypeRange.Width)); 2258 2259 // Bail out if the subexpr's range is as wide as the cast type. 2260 if (SubRange.Width >= OutputTypeRange.Width) 2261 return OutputTypeRange; 2262 2263 // Otherwise, we take the smaller width, and we're non-negative if 2264 // either the output type or the subexpr is. 2265 return IntRange(SubRange.Width, 2266 SubRange.NonNegative || OutputTypeRange.NonNegative); 2267 } 2268 2269 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { 2270 // If we can fold the condition, just take that operand. 2271 bool CondResult; 2272 if (CO->getCond()->EvaluateAsBooleanCondition(CondResult, C)) 2273 return GetExprRange(C, CondResult ? CO->getTrueExpr() 2274 : CO->getFalseExpr(), 2275 MaxWidth); 2276 2277 // Otherwise, conservatively merge. 2278 IntRange L = GetExprRange(C, CO->getTrueExpr(), MaxWidth); 2279 IntRange R = GetExprRange(C, CO->getFalseExpr(), MaxWidth); 2280 return IntRange::join(L, R); 2281 } 2282 2283 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 2284 switch (BO->getOpcode()) { 2285 2286 // Boolean-valued operations are single-bit and positive. 2287 case BO_LAnd: 2288 case BO_LOr: 2289 case BO_LT: 2290 case BO_GT: 2291 case BO_LE: 2292 case BO_GE: 2293 case BO_EQ: 2294 case BO_NE: 2295 return IntRange::forBoolType(); 2296 2297 // The type of these compound assignments is the type of the LHS, 2298 // so the RHS is not necessarily an integer. 2299 case BO_MulAssign: 2300 case BO_DivAssign: 2301 case BO_RemAssign: 2302 case BO_AddAssign: 2303 case BO_SubAssign: 2304 return IntRange::forType(C, E->getType()); 2305 2306 // Operations with opaque sources are black-listed. 2307 case BO_PtrMemD: 2308 case BO_PtrMemI: 2309 return IntRange::forType(C, E->getType()); 2310 2311 // Bitwise-and uses the *infinum* of the two source ranges. 2312 case BO_And: 2313 case BO_AndAssign: 2314 return IntRange::meet(GetExprRange(C, BO->getLHS(), MaxWidth), 2315 GetExprRange(C, BO->getRHS(), MaxWidth)); 2316 2317 // Left shift gets black-listed based on a judgement call. 2318 case BO_Shl: 2319 // ...except that we want to treat '1 << (blah)' as logically 2320 // positive. It's an important idiom. 2321 if (IntegerLiteral *I 2322 = dyn_cast<IntegerLiteral>(BO->getLHS()->IgnoreParenCasts())) { 2323 if (I->getValue() == 1) { 2324 IntRange R = IntRange::forType(C, E->getType()); 2325 return IntRange(R.Width, /*NonNegative*/ true); 2326 } 2327 } 2328 // fallthrough 2329 2330 case BO_ShlAssign: 2331 return IntRange::forType(C, E->getType()); 2332 2333 // Right shift by a constant can narrow its left argument. 2334 case BO_Shr: 2335 case BO_ShrAssign: { 2336 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth); 2337 2338 // If the shift amount is a positive constant, drop the width by 2339 // that much. 2340 llvm::APSInt shift; 2341 if (BO->getRHS()->isIntegerConstantExpr(shift, C) && 2342 shift.isNonNegative()) { 2343 unsigned zext = shift.getZExtValue(); 2344 if (zext >= L.Width) 2345 L.Width = (L.NonNegative ? 0 : 1); 2346 else 2347 L.Width -= zext; 2348 } 2349 2350 return L; 2351 } 2352 2353 // Comma acts as its right operand. 2354 case BO_Comma: 2355 return GetExprRange(C, BO->getRHS(), MaxWidth); 2356 2357 // Black-list pointer subtractions. 2358 case BO_Sub: 2359 if (BO->getLHS()->getType()->isPointerType()) 2360 return IntRange::forType(C, E->getType()); 2361 // fallthrough 2362 2363 default: 2364 break; 2365 } 2366 2367 // Treat every other operator as if it were closed on the 2368 // narrowest type that encompasses both operands. 2369 IntRange L = GetExprRange(C, BO->getLHS(), MaxWidth); 2370 IntRange R = GetExprRange(C, BO->getRHS(), MaxWidth); 2371 return IntRange::join(L, R); 2372 } 2373 2374 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) { 2375 switch (UO->getOpcode()) { 2376 // Boolean-valued operations are white-listed. 2377 case UO_LNot: 2378 return IntRange::forBoolType(); 2379 2380 // Operations with opaque sources are black-listed. 2381 case UO_Deref: 2382 case UO_AddrOf: // should be impossible 2383 return IntRange::forType(C, E->getType()); 2384 2385 default: 2386 return GetExprRange(C, UO->getSubExpr(), MaxWidth); 2387 } 2388 } 2389 2390 if (dyn_cast<OffsetOfExpr>(E)) { 2391 IntRange::forType(C, E->getType()); 2392 } 2393 2394 FieldDecl *BitField = E->getBitField(); 2395 if (BitField) { 2396 llvm::APSInt BitWidthAP = BitField->getBitWidth()->EvaluateAsInt(C); 2397 unsigned BitWidth = BitWidthAP.getZExtValue(); 2398 2399 return IntRange(BitWidth, BitField->getType()->isUnsignedIntegerType()); 2400 } 2401 2402 return IntRange::forType(C, E->getType()); 2403} 2404 2405IntRange GetExprRange(ASTContext &C, Expr *E) { 2406 return GetExprRange(C, E, C.getIntWidth(E->getType())); 2407} 2408 2409/// Checks whether the given value, which currently has the given 2410/// source semantics, has the same value when coerced through the 2411/// target semantics. 2412bool IsSameFloatAfterCast(const llvm::APFloat &value, 2413 const llvm::fltSemantics &Src, 2414 const llvm::fltSemantics &Tgt) { 2415 llvm::APFloat truncated = value; 2416 2417 bool ignored; 2418 truncated.convert(Src, llvm::APFloat::rmNearestTiesToEven, &ignored); 2419 truncated.convert(Tgt, llvm::APFloat::rmNearestTiesToEven, &ignored); 2420 2421 return truncated.bitwiseIsEqual(value); 2422} 2423 2424/// Checks whether the given value, which currently has the given 2425/// source semantics, has the same value when coerced through the 2426/// target semantics. 2427/// 2428/// The value might be a vector of floats (or a complex number). 2429bool IsSameFloatAfterCast(const APValue &value, 2430 const llvm::fltSemantics &Src, 2431 const llvm::fltSemantics &Tgt) { 2432 if (value.isFloat()) 2433 return IsSameFloatAfterCast(value.getFloat(), Src, Tgt); 2434 2435 if (value.isVector()) { 2436 for (unsigned i = 0, e = value.getVectorLength(); i != e; ++i) 2437 if (!IsSameFloatAfterCast(value.getVectorElt(i), Src, Tgt)) 2438 return false; 2439 return true; 2440 } 2441 2442 assert(value.isComplexFloat()); 2443 return (IsSameFloatAfterCast(value.getComplexFloatReal(), Src, Tgt) && 2444 IsSameFloatAfterCast(value.getComplexFloatImag(), Src, Tgt)); 2445} 2446 2447void AnalyzeImplicitConversions(Sema &S, Expr *E, SourceLocation CC); 2448 2449static bool IsZero(Sema &S, Expr *E) { 2450 // Suppress cases where we are comparing against an enum constant. 2451 if (const DeclRefExpr *DR = 2452 dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts())) 2453 if (isa<EnumConstantDecl>(DR->getDecl())) 2454 return false; 2455 2456 // Suppress cases where the '0' value is expanded from a macro. 2457 if (E->getLocStart().isMacroID()) 2458 return false; 2459 2460 llvm::APSInt Value; 2461 return E->isIntegerConstantExpr(Value, S.Context) && Value == 0; 2462} 2463 2464static bool HasEnumType(Expr *E) { 2465 // Strip off implicit integral promotions. 2466 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 2467 if (ICE->getCastKind() != CK_IntegralCast && 2468 ICE->getCastKind() != CK_NoOp) 2469 break; 2470 E = ICE->getSubExpr(); 2471 } 2472 2473 return E->getType()->isEnumeralType(); 2474} 2475 2476void CheckTrivialUnsignedComparison(Sema &S, BinaryOperator *E) { 2477 BinaryOperatorKind op = E->getOpcode(); 2478 if (op == BO_LT && IsZero(S, E->getRHS())) { 2479 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison) 2480 << "< 0" << "false" << HasEnumType(E->getLHS()) 2481 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange(); 2482 } else if (op == BO_GE && IsZero(S, E->getRHS())) { 2483 S.Diag(E->getOperatorLoc(), diag::warn_lunsigned_always_true_comparison) 2484 << ">= 0" << "true" << HasEnumType(E->getLHS()) 2485 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange(); 2486 } else if (op == BO_GT && IsZero(S, E->getLHS())) { 2487 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison) 2488 << "0 >" << "false" << HasEnumType(E->getRHS()) 2489 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange(); 2490 } else if (op == BO_LE && IsZero(S, E->getLHS())) { 2491 S.Diag(E->getOperatorLoc(), diag::warn_runsigned_always_true_comparison) 2492 << "0 <=" << "true" << HasEnumType(E->getRHS()) 2493 << E->getLHS()->getSourceRange() << E->getRHS()->getSourceRange(); 2494 } 2495} 2496 2497/// Analyze the operands of the given comparison. Implements the 2498/// fallback case from AnalyzeComparison. 2499void AnalyzeImpConvsInComparison(Sema &S, BinaryOperator *E) { 2500 AnalyzeImplicitConversions(S, E->getLHS(), E->getOperatorLoc()); 2501 AnalyzeImplicitConversions(S, E->getRHS(), E->getOperatorLoc()); 2502} 2503 2504/// \brief Implements -Wsign-compare. 2505/// 2506/// \param lex the left-hand expression 2507/// \param rex the right-hand expression 2508/// \param OpLoc the location of the joining operator 2509/// \param BinOpc binary opcode or 0 2510void AnalyzeComparison(Sema &S, BinaryOperator *E) { 2511 // The type the comparison is being performed in. 2512 QualType T = E->getLHS()->getType(); 2513 assert(S.Context.hasSameUnqualifiedType(T, E->getRHS()->getType()) 2514 && "comparison with mismatched types"); 2515 2516 // We don't do anything special if this isn't an unsigned integral 2517 // comparison: we're only interested in integral comparisons, and 2518 // signed comparisons only happen in cases we don't care to warn about. 2519 if (!T->hasUnsignedIntegerRepresentation()) 2520 return AnalyzeImpConvsInComparison(S, E); 2521 2522 Expr *lex = E->getLHS()->IgnoreParenImpCasts(); 2523 Expr *rex = E->getRHS()->IgnoreParenImpCasts(); 2524 2525 // Check to see if one of the (unmodified) operands is of different 2526 // signedness. 2527 Expr *signedOperand, *unsignedOperand; 2528 if (lex->getType()->hasSignedIntegerRepresentation()) { 2529 assert(!rex->getType()->hasSignedIntegerRepresentation() && 2530 "unsigned comparison between two signed integer expressions?"); 2531 signedOperand = lex; 2532 unsignedOperand = rex; 2533 } else if (rex->getType()->hasSignedIntegerRepresentation()) { 2534 signedOperand = rex; 2535 unsignedOperand = lex; 2536 } else { 2537 CheckTrivialUnsignedComparison(S, E); 2538 return AnalyzeImpConvsInComparison(S, E); 2539 } 2540 2541 // Otherwise, calculate the effective range of the signed operand. 2542 IntRange signedRange = GetExprRange(S.Context, signedOperand); 2543 2544 // Go ahead and analyze implicit conversions in the operands. Note 2545 // that we skip the implicit conversions on both sides. 2546 AnalyzeImplicitConversions(S, lex, E->getOperatorLoc()); 2547 AnalyzeImplicitConversions(S, rex, E->getOperatorLoc()); 2548 2549 // If the signed range is non-negative, -Wsign-compare won't fire, 2550 // but we should still check for comparisons which are always true 2551 // or false. 2552 if (signedRange.NonNegative) 2553 return CheckTrivialUnsignedComparison(S, E); 2554 2555 // For (in)equality comparisons, if the unsigned operand is a 2556 // constant which cannot collide with a overflowed signed operand, 2557 // then reinterpreting the signed operand as unsigned will not 2558 // change the result of the comparison. 2559 if (E->isEqualityOp()) { 2560 unsigned comparisonWidth = S.Context.getIntWidth(T); 2561 IntRange unsignedRange = GetExprRange(S.Context, unsignedOperand); 2562 2563 // We should never be unable to prove that the unsigned operand is 2564 // non-negative. 2565 assert(unsignedRange.NonNegative && "unsigned range includes negative?"); 2566 2567 if (unsignedRange.Width < comparisonWidth) 2568 return; 2569 } 2570 2571 S.Diag(E->getOperatorLoc(), diag::warn_mixed_sign_comparison) 2572 << lex->getType() << rex->getType() 2573 << lex->getSourceRange() << rex->getSourceRange(); 2574} 2575 2576/// Diagnose an implicit cast; purely a helper for CheckImplicitConversion. 2577void DiagnoseImpCast(Sema &S, Expr *E, QualType T, SourceLocation CContext, 2578 unsigned diag) { 2579 S.Diag(E->getExprLoc(), diag) 2580 << E->getType() << T << E->getSourceRange() << SourceRange(CContext); 2581} 2582 2583void CheckImplicitConversion(Sema &S, Expr *E, QualType T, 2584 SourceLocation CC, bool *ICContext = 0) { 2585 if (E->isTypeDependent() || E->isValueDependent()) return; 2586 2587 const Type *Source = S.Context.getCanonicalType(E->getType()).getTypePtr(); 2588 const Type *Target = S.Context.getCanonicalType(T).getTypePtr(); 2589 if (Source == Target) return; 2590 if (Target->isDependentType()) return; 2591 2592 // If the conversion context location is invalid or instantiated 2593 // from a system macro, don't complain. 2594 if (CC.isInvalid() || 2595 (CC.isMacroID() && S.Context.getSourceManager().isInSystemHeader( 2596 S.Context.getSourceManager().getSpellingLoc(CC)))) 2597 return; 2598 2599 // Never diagnose implicit casts to bool. 2600 if (Target->isSpecificBuiltinType(BuiltinType::Bool)) 2601 return; 2602 2603 // Strip vector types. 2604 if (isa<VectorType>(Source)) { 2605 if (!isa<VectorType>(Target)) 2606 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_vector_scalar); 2607 2608 Source = cast<VectorType>(Source)->getElementType().getTypePtr(); 2609 Target = cast<VectorType>(Target)->getElementType().getTypePtr(); 2610 } 2611 2612 // Strip complex types. 2613 if (isa<ComplexType>(Source)) { 2614 if (!isa<ComplexType>(Target)) 2615 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_complex_scalar); 2616 2617 Source = cast<ComplexType>(Source)->getElementType().getTypePtr(); 2618 Target = cast<ComplexType>(Target)->getElementType().getTypePtr(); 2619 } 2620 2621 const BuiltinType *SourceBT = dyn_cast<BuiltinType>(Source); 2622 const BuiltinType *TargetBT = dyn_cast<BuiltinType>(Target); 2623 2624 // If the source is floating point... 2625 if (SourceBT && SourceBT->isFloatingPoint()) { 2626 // ...and the target is floating point... 2627 if (TargetBT && TargetBT->isFloatingPoint()) { 2628 // ...then warn if we're dropping FP rank. 2629 2630 // Builtin FP kinds are ordered by increasing FP rank. 2631 if (SourceBT->getKind() > TargetBT->getKind()) { 2632 // Don't warn about float constants that are precisely 2633 // representable in the target type. 2634 Expr::EvalResult result; 2635 if (E->Evaluate(result, S.Context)) { 2636 // Value might be a float, a float vector, or a float complex. 2637 if (IsSameFloatAfterCast(result.Val, 2638 S.Context.getFloatTypeSemantics(QualType(TargetBT, 0)), 2639 S.Context.getFloatTypeSemantics(QualType(SourceBT, 0)))) 2640 return; 2641 } 2642 2643 DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_precision); 2644 } 2645 return; 2646 } 2647 2648 // If the target is integral, always warn. 2649 if ((TargetBT && TargetBT->isInteger())) 2650 // TODO: don't warn for integer values? 2651 DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_integer); 2652 2653 return; 2654 } 2655 2656 if (!Source->isIntegerType() || !Target->isIntegerType()) 2657 return; 2658 2659 IntRange SourceRange = GetExprRange(S.Context, E); 2660 IntRange TargetRange = IntRange::forCanonicalType(S.Context, Target); 2661 2662 if (SourceRange.Width > TargetRange.Width) { 2663 // People want to build with -Wshorten-64-to-32 and not -Wconversion 2664 // and by god we'll let them. 2665 if (SourceRange.Width == 64 && TargetRange.Width == 32) 2666 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_64_32); 2667 return DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_integer_precision); 2668 } 2669 2670 if ((TargetRange.NonNegative && !SourceRange.NonNegative) || 2671 (!TargetRange.NonNegative && SourceRange.NonNegative && 2672 SourceRange.Width == TargetRange.Width)) { 2673 unsigned DiagID = diag::warn_impcast_integer_sign; 2674 2675 // Traditionally, gcc has warned about this under -Wsign-compare. 2676 // We also want to warn about it in -Wconversion. 2677 // So if -Wconversion is off, use a completely identical diagnostic 2678 // in the sign-compare group. 2679 // The conditional-checking code will 2680 if (ICContext) { 2681 DiagID = diag::warn_impcast_integer_sign_conditional; 2682 *ICContext = true; 2683 } 2684 2685 return DiagnoseImpCast(S, E, T, CC, DiagID); 2686 } 2687 2688 return; 2689} 2690 2691void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T); 2692 2693void CheckConditionalOperand(Sema &S, Expr *E, QualType T, 2694 SourceLocation CC, bool &ICContext) { 2695 E = E->IgnoreParenImpCasts(); 2696 2697 if (isa<ConditionalOperator>(E)) 2698 return CheckConditionalOperator(S, cast<ConditionalOperator>(E), T); 2699 2700 AnalyzeImplicitConversions(S, E, CC); 2701 if (E->getType() != T) 2702 return CheckImplicitConversion(S, E, T, CC, &ICContext); 2703 return; 2704} 2705 2706void CheckConditionalOperator(Sema &S, ConditionalOperator *E, QualType T) { 2707 SourceLocation CC = E->getQuestionLoc(); 2708 2709 AnalyzeImplicitConversions(S, E->getCond(), CC); 2710 2711 bool Suspicious = false; 2712 CheckConditionalOperand(S, E->getTrueExpr(), T, CC, Suspicious); 2713 CheckConditionalOperand(S, E->getFalseExpr(), T, CC, Suspicious); 2714 2715 // If -Wconversion would have warned about either of the candidates 2716 // for a signedness conversion to the context type... 2717 if (!Suspicious) return; 2718 2719 // ...but it's currently ignored... 2720 if (S.Diags.getDiagnosticLevel(diag::warn_impcast_integer_sign_conditional)) 2721 return; 2722 2723 // ...and -Wsign-compare isn't... 2724 if (!S.Diags.getDiagnosticLevel(diag::warn_mixed_sign_conditional)) 2725 return; 2726 2727 // ...then check whether it would have warned about either of the 2728 // candidates for a signedness conversion to the condition type. 2729 if (E->getType() != T) { 2730 Suspicious = false; 2731 CheckImplicitConversion(S, E->getTrueExpr()->IgnoreParenImpCasts(), 2732 E->getType(), CC, &Suspicious); 2733 if (!Suspicious) 2734 CheckImplicitConversion(S, E->getFalseExpr()->IgnoreParenImpCasts(), 2735 E->getType(), CC, &Suspicious); 2736 if (!Suspicious) 2737 return; 2738 } 2739 2740 // If so, emit a diagnostic under -Wsign-compare. 2741 Expr *lex = E->getTrueExpr()->IgnoreParenImpCasts(); 2742 Expr *rex = E->getFalseExpr()->IgnoreParenImpCasts(); 2743 S.Diag(E->getQuestionLoc(), diag::warn_mixed_sign_conditional) 2744 << lex->getType() << rex->getType() 2745 << lex->getSourceRange() << rex->getSourceRange(); 2746} 2747 2748/// AnalyzeImplicitConversions - Find and report any interesting 2749/// implicit conversions in the given expression. There are a couple 2750/// of competing diagnostics here, -Wconversion and -Wsign-compare. 2751void AnalyzeImplicitConversions(Sema &S, Expr *OrigE, SourceLocation CC) { 2752 QualType T = OrigE->getType(); 2753 Expr *E = OrigE->IgnoreParenImpCasts(); 2754 2755 // For conditional operators, we analyze the arguments as if they 2756 // were being fed directly into the output. 2757 if (isa<ConditionalOperator>(E)) { 2758 ConditionalOperator *CO = cast<ConditionalOperator>(E); 2759 CheckConditionalOperator(S, CO, T); 2760 return; 2761 } 2762 2763 // Go ahead and check any implicit conversions we might have skipped. 2764 // The non-canonical typecheck is just an optimization; 2765 // CheckImplicitConversion will filter out dead implicit conversions. 2766 if (E->getType() != T) 2767 CheckImplicitConversion(S, E, T, CC); 2768 2769 // Now continue drilling into this expression. 2770 2771 // Skip past explicit casts. 2772 if (isa<ExplicitCastExpr>(E)) { 2773 E = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreParenImpCasts(); 2774 return AnalyzeImplicitConversions(S, E, CC); 2775 } 2776 2777 // Do a somewhat different check with comparison operators. 2778 if (isa<BinaryOperator>(E) && cast<BinaryOperator>(E)->isComparisonOp()) 2779 return AnalyzeComparison(S, cast<BinaryOperator>(E)); 2780 2781 // These break the otherwise-useful invariant below. Fortunately, 2782 // we don't really need to recurse into them, because any internal 2783 // expressions should have been analyzed already when they were 2784 // built into statements. 2785 if (isa<StmtExpr>(E)) return; 2786 2787 // Don't descend into unevaluated contexts. 2788 if (isa<SizeOfAlignOfExpr>(E)) return; 2789 2790 // Now just recurse over the expression's children. 2791 CC = E->getExprLoc(); 2792 for (Stmt::child_iterator I = E->child_begin(), IE = E->child_end(); 2793 I != IE; ++I) 2794 AnalyzeImplicitConversions(S, cast<Expr>(*I), CC); 2795} 2796 2797} // end anonymous namespace 2798 2799/// Diagnoses "dangerous" implicit conversions within the given 2800/// expression (which is a full expression). Implements -Wconversion 2801/// and -Wsign-compare. 2802/// 2803/// \param CC the "context" location of the implicit conversion, i.e. 2804/// the most location of the syntactic entity requiring the implicit 2805/// conversion 2806void Sema::CheckImplicitConversions(Expr *E, SourceLocation CC) { 2807 // Don't diagnose in unevaluated contexts. 2808 if (ExprEvalContexts.back().Context == Sema::Unevaluated) 2809 return; 2810 2811 // Don't diagnose for value- or type-dependent expressions. 2812 if (E->isTypeDependent() || E->isValueDependent()) 2813 return; 2814 2815 // This is not the right CC for (e.g.) a variable initialization. 2816 AnalyzeImplicitConversions(*this, E, CC); 2817} 2818 2819/// CheckParmsForFunctionDef - Check that the parameters of the given 2820/// function are appropriate for the definition of a function. This 2821/// takes care of any checks that cannot be performed on the 2822/// declaration itself, e.g., that the types of each of the function 2823/// parameters are complete. 2824bool Sema::CheckParmsForFunctionDef(FunctionDecl *FD) { 2825 bool HasInvalidParm = false; 2826 for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) { 2827 ParmVarDecl *Param = FD->getParamDecl(p); 2828 2829 // C99 6.7.5.3p4: the parameters in a parameter type list in a 2830 // function declarator that is part of a function definition of 2831 // that function shall not have incomplete type. 2832 // 2833 // This is also C++ [dcl.fct]p6. 2834 if (!Param->isInvalidDecl() && 2835 RequireCompleteType(Param->getLocation(), Param->getType(), 2836 diag::err_typecheck_decl_incomplete_type)) { 2837 Param->setInvalidDecl(); 2838 HasInvalidParm = true; 2839 } 2840 2841 // C99 6.9.1p5: If the declarator includes a parameter type list, the 2842 // declaration of each parameter shall include an identifier. 2843 if (Param->getIdentifier() == 0 && 2844 !Param->isImplicit() && 2845 !getLangOptions().CPlusPlus) 2846 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 2847 2848 // C99 6.7.5.3p12: 2849 // If the function declarator is not part of a definition of that 2850 // function, parameters may have incomplete type and may use the [*] 2851 // notation in their sequences of declarator specifiers to specify 2852 // variable length array types. 2853 QualType PType = Param->getOriginalType(); 2854 if (const ArrayType *AT = Context.getAsArrayType(PType)) { 2855 if (AT->getSizeModifier() == ArrayType::Star) { 2856 // FIXME: This diagnosic should point the the '[*]' if source-location 2857 // information is added for it. 2858 Diag(Param->getLocation(), diag::err_array_star_in_function_definition); 2859 } 2860 } 2861 } 2862 2863 return HasInvalidParm; 2864} 2865 2866/// CheckCastAlign - Implements -Wcast-align, which warns when a 2867/// pointer cast increases the alignment requirements. 2868void Sema::CheckCastAlign(Expr *Op, QualType T, SourceRange TRange) { 2869 // This is actually a lot of work to potentially be doing on every 2870 // cast; don't do it if we're ignoring -Wcast_align (as is the default). 2871 if (getDiagnostics().getDiagnosticLevel(diag::warn_cast_align) 2872 == Diagnostic::Ignored) 2873 return; 2874 2875 // Ignore dependent types. 2876 if (T->isDependentType() || Op->getType()->isDependentType()) 2877 return; 2878 2879 // Require that the destination be a pointer type. 2880 const PointerType *DestPtr = T->getAs<PointerType>(); 2881 if (!DestPtr) return; 2882 2883 // If the destination has alignment 1, we're done. 2884 QualType DestPointee = DestPtr->getPointeeType(); 2885 if (DestPointee->isIncompleteType()) return; 2886 CharUnits DestAlign = Context.getTypeAlignInChars(DestPointee); 2887 if (DestAlign.isOne()) return; 2888 2889 // Require that the source be a pointer type. 2890 const PointerType *SrcPtr = Op->getType()->getAs<PointerType>(); 2891 if (!SrcPtr) return; 2892 QualType SrcPointee = SrcPtr->getPointeeType(); 2893 2894 // Whitelist casts from cv void*. We already implicitly 2895 // whitelisted casts to cv void*, since they have alignment 1. 2896 // Also whitelist casts involving incomplete types, which implicitly 2897 // includes 'void'. 2898 if (SrcPointee->isIncompleteType()) return; 2899 2900 CharUnits SrcAlign = Context.getTypeAlignInChars(SrcPointee); 2901 if (SrcAlign >= DestAlign) return; 2902 2903 Diag(TRange.getBegin(), diag::warn_cast_align) 2904 << Op->getType() << T 2905 << static_cast<unsigned>(SrcAlign.getQuantity()) 2906 << static_cast<unsigned>(DestAlign.getQuantity()) 2907 << TRange << Op->getSourceRange(); 2908} 2909 2910