SemaChecking.cpp revision b7cfe88e88cb4f46308de89cf3f0c81bfe624128
159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner//===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===// 259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// The LLVM Compiler Infrastructure 459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 50bc735ffcfb223c0186419547abaa5c84482663eChris Lattner// This file is distributed under the University of Illinois Open Source 60bc735ffcfb223c0186419547abaa5c84482663eChris Lattner// License. See LICENSE.TXT for details. 759907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner//===----------------------------------------------------------------------===// 959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 1059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// This file implements extra semantic analysis beyond what is enforced 1159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// by the C type system. 1259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 1359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner//===----------------------------------------------------------------------===// 1459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 1559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "Sema.h" 1659907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/AST/ASTContext.h" 1759907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/AST/Decl.h" 1859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/AST/Expr.h" 192324512285caac0332bbbc6e4cab6245d2a370a1Ted Kremenek#include "clang/AST/ExprCXX.h" 207ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek#include "clang/AST/ExprObjC.h" 2159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Lex/Preprocessor.h" 2259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Lex/LiteralSupport.h" 2359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Basic/SourceManager.h" 2459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Basic/Diagnostic.h" 2559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Basic/LangOptions.h" 2659907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Basic/TargetInfo.h" 27e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman#include "llvm/ADT/OwningPtr.h" 2859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "llvm/ADT/SmallString.h" 2959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "llvm/ADT/StringExtras.h" 30588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek#include "SemaUtil.h" 3159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattnerusing namespace clang; 3259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 3359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// CheckFunctionCall - Check a direct function call for various correctness 3459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// and safety properties not strictly enforced by the C type system. 35d38617c8a50f9729c254ab76cd359af797c6739bEli FriedmanAction::ExprResult 36e801870b638e47a5734a3ea63ddfb45f1711e078Eli FriedmanSema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCallRaw) { 37e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman llvm::OwningPtr<CallExpr> TheCall(TheCallRaw); 3859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // Get the IdentifierInfo* for the called function. 3959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner IdentifierInfo *FnInfo = FDecl->getIdentifier(); 4059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 4130ce344307f8a8b00054021307015571f83c7364Chris Lattner switch (FnInfo->getBuiltinID()) { 4230ce344307f8a8b00054021307015571f83c7364Chris Lattner case Builtin::BI__builtin___CFStringMakeConstantString: 43925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner assert(TheCall->getNumArgs() == 1 && 441b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner "Wrong # arguments to builtin CFStringMakeConstantString"); 45e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (CheckBuiltinCFStringArgument(TheCall->getArg(0))) 46d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 47e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 4830ce344307f8a8b00054021307015571f83c7364Chris Lattner case Builtin::BI__builtin_va_start: 49b7cfe88e88cb4f46308de89cf3f0c81bfe624128Chris Lattner if (SemaBuiltinVAStart(TheCall.get())) 50d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 51e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 521b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isgreater: 531b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isgreaterequal: 541b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isless: 551b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_islessequal: 561b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_islessgreater: 571b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isunordered: 58e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (SemaBuiltinUnorderedCompare(TheCall.get())) 59d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 60e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 616cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman case Builtin::BI__builtin_return_address: 626cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman case Builtin::BI__builtin_frame_address: 636cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman if (SemaBuiltinStackAddress(TheCall.get())) 646cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return true; 656cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return TheCall.take(); 66d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman case Builtin::BI__builtin_shufflevector: 67e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return SemaBuiltinShuffleVector(TheCall.get()); 6871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 6971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 7059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // Search the KnownFunctionIDs for the identifier. 7159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner unsigned i = 0, e = id_num_known_functions; 7271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek for (; i != e; ++i) { if (KnownFunctionIDs[i] == FnInfo) break; } 73e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (i == e) return TheCall.take(); 7459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 7559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // Printf checking. 7659907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner if (i <= id_vprintf) { 7771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Retrieve the index of the format string parameter and determine 7871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // if the function is passed a va_arg argument. 7959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner unsigned format_idx = 0; 8071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek bool HasVAListArg = false; 8171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 8259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner switch (i) { 8330ce344307f8a8b00054021307015571f83c7364Chris Lattner default: assert(false && "No format string argument index."); 8430ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_printf: format_idx = 0; break; 8530ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_fprintf: format_idx = 1; break; 8630ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_sprintf: format_idx = 1; break; 8730ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_snprintf: format_idx = 2; break; 8830ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_asprintf: format_idx = 1; break; 897ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek case id_NSLog: format_idx = 0; break; 9030ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vsnprintf: format_idx = 2; HasVAListArg = true; break; 9130ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vasprintf: format_idx = 1; HasVAListArg = true; break; 9230ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vfprintf: format_idx = 1; HasVAListArg = true; break; 9330ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vsprintf: format_idx = 1; HasVAListArg = true; break; 9430ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vprintf: format_idx = 0; HasVAListArg = true; break; 9571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 9671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 97e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman CheckPrintfArguments(TheCall.get(), HasVAListArg, format_idx); 9859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner } 9971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 100e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 10171993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson} 10271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 10371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson/// CheckBuiltinCFStringArgument - Checks that the argument to the builtin 10471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson/// CFString constructor is correct 105cc6f65d9f210efc56d7418753e93bf5a14f3ac59Chris Lattnerbool Sema::CheckBuiltinCFStringArgument(Expr* Arg) { 10656f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner Arg = Arg->IgnoreParenCasts(); 10771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 10871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson StringLiteral *Literal = dyn_cast<StringLiteral>(Arg); 10971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 11071993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson if (!Literal || Literal->isWide()) { 11171993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Diag(Arg->getLocStart(), 11271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson diag::err_cfstring_literal_not_string_constant, 11371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Arg->getSourceRange()); 1149cdc4d3834f203dcde3ff274b8928e4620a914d5Anders Carlsson return true; 11571993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 11671993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 11771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson const char *Data = Literal->getStrData(); 11871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson unsigned Length = Literal->getByteLength(); 11971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 12071993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson for (unsigned i = 0; i < Length; ++i) { 12171993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson if (!isascii(Data[i])) { 12271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Diag(PP.AdvanceToTokenCharacter(Arg->getLocStart(), i + 1), 12371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson diag::warn_cfstring_literal_contains_non_ascii_character, 12471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Arg->getSourceRange()); 12571993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson break; 12671993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 12771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 12871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson if (!Data[i]) { 12971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Diag(PP.AdvanceToTokenCharacter(Arg->getLocStart(), i + 1), 13071993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson diag::warn_cfstring_literal_contains_nul_character, 13171993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Arg->getSourceRange()); 13271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson break; 13371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 13471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 13571993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 1369cdc4d3834f203dcde3ff274b8928e4620a914d5Anders Carlsson return false; 13759907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner} 13859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 139c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity. 140c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner/// Emit an error and return true on failure, return false on success. 141925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattnerbool Sema::SemaBuiltinVAStart(CallExpr *TheCall) { 142925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *Fn = TheCall->getCallee(); 143925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (TheCall->getNumArgs() > 2) { 144925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(2)->getLocStart(), 14530ce344307f8a8b00054021307015571f83c7364Chris Lattner diag::err_typecheck_call_too_many_args, Fn->getSourceRange(), 146925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceRange(TheCall->getArg(2)->getLocStart(), 147925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner (*(TheCall->arg_end()-1))->getLocEnd())); 14830ce344307f8a8b00054021307015571f83c7364Chris Lattner return true; 14930ce344307f8a8b00054021307015571f83c7364Chris Lattner } 15030ce344307f8a8b00054021307015571f83c7364Chris Lattner 151c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner // Determine whether the current function is variadic or not. 152c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner bool isVariadic; 15353d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis if (getCurFunctionDecl()) 154c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner isVariadic = 15553d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis cast<FunctionTypeProto>(getCurFunctionDecl()->getType())->isVariadic(); 15630ce344307f8a8b00054021307015571f83c7364Chris Lattner else 15753d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis isVariadic = getCurMethodDecl()->isVariadic(); 15830ce344307f8a8b00054021307015571f83c7364Chris Lattner 159c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner if (!isVariadic) { 16030ce344307f8a8b00054021307015571f83c7364Chris Lattner Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function); 16130ce344307f8a8b00054021307015571f83c7364Chris Lattner return true; 16230ce344307f8a8b00054021307015571f83c7364Chris Lattner } 16330ce344307f8a8b00054021307015571f83c7364Chris Lattner 16430ce344307f8a8b00054021307015571f83c7364Chris Lattner // Verify that the second argument to the builtin is the last argument of the 16530ce344307f8a8b00054021307015571f83c7364Chris Lattner // current function or method. 16630ce344307f8a8b00054021307015571f83c7364Chris Lattner bool SecondArgIsLastNamedArgument = false; 167e2c14103dec39cbd24dac9d7b3e91277b109c14fAnders Carlsson const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts(); 16888cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson 16988cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) { 17088cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) { 17130ce344307f8a8b00054021307015571f83c7364Chris Lattner // FIXME: This isn't correct for methods (results in bogus warning). 17230ce344307f8a8b00054021307015571f83c7364Chris Lattner // Get the last formal in the current function. 17388cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson const ParmVarDecl *LastArg; 17453d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis if (getCurFunctionDecl()) 17553d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis LastArg = *(getCurFunctionDecl()->param_end()-1); 17630ce344307f8a8b00054021307015571f83c7364Chris Lattner else 17753d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis LastArg = *(getCurMethodDecl()->param_end()-1); 17830ce344307f8a8b00054021307015571f83c7364Chris Lattner SecondArgIsLastNamedArgument = PV == LastArg; 17930ce344307f8a8b00054021307015571f83c7364Chris Lattner } 18030ce344307f8a8b00054021307015571f83c7364Chris Lattner } 18130ce344307f8a8b00054021307015571f83c7364Chris Lattner 18230ce344307f8a8b00054021307015571f83c7364Chris Lattner if (!SecondArgIsLastNamedArgument) 183925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(1)->getLocStart(), 18430ce344307f8a8b00054021307015571f83c7364Chris Lattner diag::warn_second_parameter_of_va_start_not_last_named_argument); 18530ce344307f8a8b00054021307015571f83c7364Chris Lattner return false; 1866cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman} 18730ce344307f8a8b00054021307015571f83c7364Chris Lattner 1881b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and 1891b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner/// friends. This is declared to take (...), so we have to check everything. 190925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattnerbool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) { 191925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (TheCall->getNumArgs() < 2) 192925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args); 193925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (TheCall->getNumArgs() > 2) 194925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner return Diag(TheCall->getArg(2)->getLocStart(), 195925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner diag::err_typecheck_call_too_many_args, 196925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceRange(TheCall->getArg(2)->getLocStart(), 197925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner (*(TheCall->arg_end()-1))->getLocEnd())); 1981b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 199925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *OrigArg0 = TheCall->getArg(0); 200925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *OrigArg1 = TheCall->getArg(1); 2011b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2021b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // Do standard promotions between the two arguments, returning their common 2031b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // type. 204925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false); 2051b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2061b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // If the common type isn't a real floating type, then the arguments were 2071b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // invalid for this operation. 2081b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner if (!Res->isRealFloatingType()) 209925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner return Diag(OrigArg0->getLocStart(), 2101b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner diag::err_typecheck_call_invalid_ordered_compare, 2111b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner OrigArg0->getType().getAsString(), 2121b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner OrigArg1->getType().getAsString(), 213925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceRange(OrigArg0->getLocStart(), OrigArg1->getLocEnd())); 2141b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2151b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner return false; 2161b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner} 2171b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2186cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedmanbool Sema::SemaBuiltinStackAddress(CallExpr *TheCall) { 2196cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman // The signature for these builtins is exact; the only thing we need 2206cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman // to check is that the argument is a constant. 2216cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman SourceLocation Loc; 2226cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman if (!TheCall->getArg(0)->isIntegerConstantExpr(Context, &Loc)) { 2236cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return Diag(Loc, diag::err_stack_const_level, TheCall->getSourceRange()); 2246cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman } 2256cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return false; 2266cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman} 2276cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman 228d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector. 229d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman// This is declared to take (...), so we have to check everything. 230d38617c8a50f9729c254ab76cd359af797c6739bEli FriedmanAction::ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) { 231d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (TheCall->getNumArgs() < 3) 232d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args, 233d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getSourceRange()); 234d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 235d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman QualType FAType = TheCall->getArg(0)->getType(); 236d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman QualType SAType = TheCall->getArg(1)->getType(); 237d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 238d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (!FAType->isVectorType() || !SAType->isVectorType()) { 239d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector, 240d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman SourceRange(TheCall->getArg(0)->getLocStart(), 241d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getArg(1)->getLocEnd())); 242d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 243d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 244d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 245ba2561a0ab11afa64014828c759c491378ccc539Eli Friedman if (FAType.getCanonicalType().getUnqualifiedType() != 246ba2561a0ab11afa64014828c759c491378ccc539Eli Friedman SAType.getCanonicalType().getUnqualifiedType()) { 247d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector, 248d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman SourceRange(TheCall->getArg(0)->getLocStart(), 249d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getArg(1)->getLocEnd())); 250d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 251d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 252d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 253d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman unsigned numElements = FAType->getAsVectorType()->getNumElements(); 254d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (TheCall->getNumArgs() != numElements+2) { 255d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (TheCall->getNumArgs() < numElements+2) 256d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args, 257d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getSourceRange()); 258d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman else 259d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_many_args, 260d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getSourceRange()); 261d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 262d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 263d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 264d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman for (unsigned i = 2; i < TheCall->getNumArgs(); i++) { 265d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman llvm::APSInt Result(32); 266d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context)) { 267d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocStart(), 268d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman diag::err_shufflevector_nonconstant_argument, 269d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getArg(i)->getSourceRange()); 270d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 271d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 272d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2) { 273d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocStart(), 274d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman diag::err_shufflevector_argument_too_large, 275d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getArg(i)->getSourceRange()); 276d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 277d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 278d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 279d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 280d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman llvm::SmallVector<Expr*, 32> exprs; 281d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 282d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman for (unsigned i = 0; i < TheCall->getNumArgs(); i++) { 283d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman exprs.push_back(TheCall->getArg(i)); 284d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->setArg(i, 0); 285d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 286d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 287d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman ShuffleVectorExpr* E = new ShuffleVectorExpr( 288d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman exprs.begin(), numElements+2, FAType, 289d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getCallee()->getLocStart(), 290d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getRParenLoc()); 291d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 292d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return E; 293d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman} 29430ce344307f8a8b00054021307015571f83c7364Chris Lattner 29559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// CheckPrintfArguments - Check calls to printf (and similar functions) for 29671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// correct use of format strings. 29771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 29871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// HasVAListArg - A predicate indicating whether the printf-like 29971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// function is passed an explicit va_arg argument (e.g., vprintf) 30071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 30171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// format_idx - The index into Args for the format string. 30271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 30371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Improper format strings to functions in the printf family can be 30471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// the source of bizarre bugs and very serious security holes. A 30571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// good source of information is available in the following paper 30671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (which includes additional references): 30759907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// 30859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// FormatGuard: Automatic Protection From printf Format String 30959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// Vulnerabilities, Proceedings of the 10th USENIX Security Symposium, 2001. 31071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 31171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Functionality implemented: 31271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 31371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// We can statically check the following properties for string 31471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// literal format strings for non v.*printf functions (where the 31571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// arguments are passed directly): 31671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek// 31771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (1) Are the number of format conversions equal to the number of 31871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// data arguments? 31971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 32071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (2) Does each format conversion correctly match the type of the 32171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// corresponding data argument? (TODO) 32271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 32371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Moreover, for all printf functions we can: 32471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 32571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (3) Check for a missing format string (when not caught by type checking). 32671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 32771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (4) Check for no-operation flags; e.g. using "#" with format 32871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// conversion 'c' (TODO) 32971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 33071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (5) Check the use of '%n', a major source of security holes. 33171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 33271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (6) Check for malformed format conversions that don't specify anything. 33371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 33471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (7) Check for empty format strings. e.g: printf(""); 33571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 33671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (8) Check that the format string is a wide literal. 33771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 3386d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// (9) Also check the arguments of functions with the __format__ attribute. 3396d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// (TODO). 3406d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// 34171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// All of these checks can be done by parsing the format string. 34271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 34371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// For now, we ONLY do (1), (3), (5), (6), (7), and (8). 34459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattnervoid 345925e60d3fa706f31886027c876989af79eb0e0d2Chris LattnerSema::CheckPrintfArguments(CallExpr *TheCall, bool HasVAListArg, 346925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner unsigned format_idx) { 347925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *Fn = TheCall->getCallee(); 348925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner 34971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: printf-like function is called with no format string. 350925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (format_idx >= TheCall->getNumArgs()) { 351925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getRParenLoc(), diag::warn_printf_missing_format_string, 35271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Fn->getSourceRange()); 35371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 35471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 35571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 35656f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts(); 357459e8488046be5df0bf57f0a8677316abf253167Chris Lattner 35859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // CHECK: format string is not a string literal. 35959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // 36071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Dynamically generated format strings are difficult to 36171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // automatically vet at compile time. Requiring that format strings 36271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // are string literals: (1) permits the checking of format strings by 36371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // the compiler and thereby (2) can practically remove the source of 36471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // many format string exploits. 3657ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 3667ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Format string can be either ObjC string (e.g. @"%d") or 3677ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // C string (e.g. "%d") 3687ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // ObjC string uses the same format specifiers as C string, so we can use 3697ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // the same format string checking logic for both ObjC and C strings. 3707ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(OrigFormatExpr); 3717ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek StringLiteral *FExpr = NULL; 3727ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 3737ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek if(ObjCFExpr != NULL) 3747ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek FExpr = ObjCFExpr->getString(); 3757ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek else 3767ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek FExpr = dyn_cast<StringLiteral>(OrigFormatExpr); 3777ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 37871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (FExpr == NULL) { 3794a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // For vprintf* functions (i.e., HasVAListArg==true), we add a 3804a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // special check to see if the format string is a function parameter 3814a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // of the function calling the printf function. If the function 3824a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // has an attribute indicating it is a printf-like function, then we 3834a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // should suppress warnings concerning non-literals being used in a call 3844a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // to a vprintf function. For example: 3854a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 3864a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // void 3874a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...) { 3884a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // va_list ap; 3894a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // va_start(ap, fmt); 3904a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // vprintf(fmt, ap); // Do NOT emit a warning about "fmt". 3914a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // ... 3924a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 3934a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 3944a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // FIXME: We don't have full attribute support yet, so just check to see 3954a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // if the argument is a DeclRefExpr that references a parameter. We'll 3964a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // add proper support for checking the attribute later. 3974a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek if (HasVAListArg) 398998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner if (DeclRefExpr* DR = dyn_cast<DeclRefExpr>(OrigFormatExpr)) 399998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner if (isa<ParmVarDecl>(DR->getDecl())) 4004a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek return; 4014a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek 402925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(format_idx)->getLocStart(), 403925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner diag::warn_printf_not_string_constant, Fn->getSourceRange()); 40471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 40571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 40671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 40771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: is the format string a wide literal? 40871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (FExpr->isWide()) { 409925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(FExpr->getLocStart(), 410925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner diag::warn_printf_format_string_is_wide_literal, Fn->getSourceRange()); 41171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 41271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 41371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 41471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Str - The format string. NOTE: this is NOT null-terminated! 41571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek const char * const Str = FExpr->getStrData(); 41671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 41771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: empty format string? 41871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek const unsigned StrLen = FExpr->getByteLength(); 41971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 42071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (StrLen == 0) { 421925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(FExpr->getLocStart(), diag::warn_printf_empty_format_string, 422925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Fn->getSourceRange()); 42371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 42471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 42571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 42671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // We process the format string using a binary state machine. The 42771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // current state is stored in CurrentState. 42871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek enum { 42971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek state_OrdChr, 43071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek state_Conversion 43171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } CurrentState = state_OrdChr; 43271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 43371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // numConversions - The number of conversions seen so far. This is 43471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // incremented as we traverse the format string. 43571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned numConversions = 0; 43671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 43771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // numDataArgs - The number of data arguments after the format 43871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // string. This can only be determined for non vprintf-like 43971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // functions. For those functions, this value is 1 (the sole 44071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // va_arg argument). 441925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner unsigned numDataArgs = TheCall->getNumArgs()-(format_idx+1); 44271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 44371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Inspect the format string. 44471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned StrIdx = 0; 44571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 44671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // LastConversionIdx - Index within the format string where we last saw 44771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // a '%' character that starts a new format conversion. 44871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned LastConversionIdx = 0; 44971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 450925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner for (; StrIdx < StrLen; ++StrIdx) { 451998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner 45271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Is the number of detected conversion conversions greater than 45371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // the number of matching data arguments? If so, stop. 45471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (!HasVAListArg && numConversions > numDataArgs) break; 45571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 45671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Handle "\0" 457925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (Str[StrIdx] == '\0') { 45871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // The string returned by getStrData() is not null-terminated, 45971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // so the presence of a null character is likely an error. 460998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner Diag(PP.AdvanceToTokenCharacter(FExpr->getLocStart(), StrIdx+1), 461998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner diag::warn_printf_format_string_contains_null_char, 46271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Fn->getSourceRange()); 46371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 46471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 46571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 46671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Ordinary characters (not processing a format conversion). 46771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (CurrentState == state_OrdChr) { 46871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (Str[StrIdx] == '%') { 46971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek CurrentState = state_Conversion; 47071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek LastConversionIdx = StrIdx; 47171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 47271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek continue; 47371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 47471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 47571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Seen '%'. Now processing a format conversion. 47671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek switch (Str[StrIdx]) { 477fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle dynamic precision or width specifier. 478fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case '*': { 479fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 480fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 481fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (!HasVAListArg && numConversions > numDataArgs) { 482fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = FExpr->getLocStart(); 483fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Loc = PP.AdvanceToTokenCharacter(Loc, StrIdx+1); 484580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek 485580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek if (Str[StrIdx-1] == '.') 486fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_precision_missing_arg, 487fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Fn->getSourceRange()); 488580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek else 489fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_width_missing_arg, 490fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Fn->getSourceRange()); 491580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek 492fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Don't do any more checking. We'll just emit spurious errors. 493fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return; 494580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek } 495fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 496fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Perform type checking on width/precision specifier. 497fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *E = TheCall->getArg(format_idx+numConversions); 498fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (const BuiltinType *BT = E->getType()->getAsBuiltinType()) 499fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (BT->getKind() == BuiltinType::Int) 500fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 501fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 502fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = 503fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner PP.AdvanceToTokenCharacter(FExpr->getLocStart(), StrIdx+1); 504fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 505fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (Str[StrIdx-1] == '.') 506fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_precision_wrong_type, 507fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner E->getType().getAsString(), E->getSourceRange()); 508fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 509fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_width_wrong_type, 510fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner E->getType().getAsString(), E->getSourceRange()); 511fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 512fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 513fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 514fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 515fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Characters which can terminate a format conversion 516fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // (e.g. "%d"). Characters that specify length modifiers or 517fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // other flags are handled by the default case below. 518fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // 519fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // FIXME: additional checks will go into the following cases. 520fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'i': 521fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'd': 522fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'o': 523fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'u': 524fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'x': 525fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'X': 526fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'D': 527fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'O': 528fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'U': 529fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'e': 530fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'E': 531fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'f': 532fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'F': 533fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'g': 534fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'G': 535fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'a': 536fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'A': 537fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'c': 538fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'C': 539fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'S': 540fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 's': 541fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'p': 542fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 543fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 544fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 54571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 546fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // CHECK: Are we using "%n"? Issue a warning. 547fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'n': { 548fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 549fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 550fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 551fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner LastConversionIdx+1); 552fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 553fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_write_back, Fn->getSourceRange()); 554fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 555fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 5567ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 5577ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Handle "%@" 5587ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek case '@': 5597ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // %@ is allowed in ObjC format strings only. 5607ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek if(ObjCFExpr != NULL) 5617ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek CurrentState = state_OrdChr; 5627ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek else { 5637ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Issue a warning: invalid format conversion. 5647ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 5657ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek LastConversionIdx+1); 5667ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 5677ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek Diag(Loc, diag::warn_printf_invalid_conversion, 5687ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek std::string(Str+LastConversionIdx, 5697ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek Str+std::min(LastConversionIdx+2, StrLen)), 5707ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek Fn->getSourceRange()); 5717ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek } 5727ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek ++numConversions; 5737ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek break; 5747ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 575fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle "%%" 576fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case '%': 577fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Sanity check: Was the first "%" character the previous one? 578fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // If not, we will assume that we have a malformed format 579fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // conversion, and that the current "%" character is the start 580fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // of a new conversion. 581fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (StrIdx - LastConversionIdx == 1) 582fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 583fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else { 584fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Issue a warning: invalid format conversion. 585925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 586925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx+1); 587fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 588fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_invalid_conversion, 589fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner std::string(Str+LastConversionIdx, Str+StrIdx), 590fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Fn->getSourceRange()); 591fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 592fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // This conversion is broken. Advance to the next format 593fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // conversion. 594fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner LastConversionIdx = StrIdx; 595fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 59671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 597fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 59871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 599fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner default: 600fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // This case catches all other characters: flags, widths, etc. 601fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // We should eventually process those as well. 602fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 60371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 60471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 60571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 60671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (CurrentState == state_Conversion) { 60771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Issue a warning: invalid format conversion. 608925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 609925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx+1); 61071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 61171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Diag(Loc, diag::warn_printf_invalid_conversion, 612a9e2ea107d9419a6406f01e513679327032da193Chris Lattner std::string(Str+LastConversionIdx, 613a9e2ea107d9419a6406f01e513679327032da193Chris Lattner Str+std::min(LastConversionIdx+2, StrLen)), 61471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Fn->getSourceRange()); 61571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 61671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 61771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 61871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (!HasVAListArg) { 61971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: Does the number of format conversions exceed the number 62071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // of data arguments? 62171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (numConversions > numDataArgs) { 622925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 623925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx); 62471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 62571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Diag(Loc, diag::warn_printf_insufficient_data_args, 62671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Fn->getSourceRange()); 62771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 62871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: Does the number of data arguments exceed the number of 62971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // format conversions in the format string? 63071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek else if (numConversions < numDataArgs) 631925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(format_idx+numConversions+1)->getLocStart(), 63271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek diag::warn_printf_too_many_data_args, Fn->getSourceRange()); 63371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 63471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek} 63506de276fff91264437fa75111ed76de43097e089Ted Kremenek 63606de276fff91264437fa75111ed76de43097e089Ted Kremenek//===--- CHECK: Return Address of Stack Variable --------------------------===// 63706de276fff91264437fa75111ed76de43097e089Ted Kremenek 63806de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalVal(Expr *E); 63906de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalAddr(Expr* E); 64006de276fff91264437fa75111ed76de43097e089Ted Kremenek 64106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// CheckReturnStackAddr - Check if a return statement returns the address 64206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// of a stack variable. 64306de276fff91264437fa75111ed76de43097e089Ted Kremenekvoid 64406de276fff91264437fa75111ed76de43097e089Ted KremenekSema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType, 64506de276fff91264437fa75111ed76de43097e089Ted Kremenek SourceLocation ReturnLoc) { 64656f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner 64706de276fff91264437fa75111ed76de43097e089Ted Kremenek // Perform checking for returned stack addresses. 64806de276fff91264437fa75111ed76de43097e089Ted Kremenek if (lhsType->isPointerType()) { 64906de276fff91264437fa75111ed76de43097e089Ted Kremenek if (DeclRefExpr *DR = EvalAddr(RetValExp)) 65006de276fff91264437fa75111ed76de43097e089Ted Kremenek Diag(DR->getLocStart(), diag::warn_ret_stack_addr, 65106de276fff91264437fa75111ed76de43097e089Ted Kremenek DR->getDecl()->getIdentifier()->getName(), 65206de276fff91264437fa75111ed76de43097e089Ted Kremenek RetValExp->getSourceRange()); 65306de276fff91264437fa75111ed76de43097e089Ted Kremenek } 65406de276fff91264437fa75111ed76de43097e089Ted Kremenek // Perform checking for stack values returned by reference. 65506de276fff91264437fa75111ed76de43097e089Ted Kremenek else if (lhsType->isReferenceType()) { 65696eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek // Check for an implicit cast to a reference. 65796eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek if (ImplicitCastExpr *I = dyn_cast<ImplicitCastExpr>(RetValExp)) 65896eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek if (DeclRefExpr *DR = EvalVal(I->getSubExpr())) 65996eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek Diag(DR->getLocStart(), diag::warn_ret_stack_ref, 66096eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek DR->getDecl()->getIdentifier()->getName(), 66196eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek RetValExp->getSourceRange()); 66206de276fff91264437fa75111ed76de43097e089Ted Kremenek } 66306de276fff91264437fa75111ed76de43097e089Ted Kremenek} 66406de276fff91264437fa75111ed76de43097e089Ted Kremenek 66506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that 66606de276fff91264437fa75111ed76de43097e089Ted Kremenek/// check if the expression in a return statement evaluates to an address 66706de276fff91264437fa75111ed76de43097e089Ted Kremenek/// to a location on the stack. The recursion is used to traverse the 66806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// AST of the return expression, with recursion backtracking when we 66906de276fff91264437fa75111ed76de43097e089Ted Kremenek/// encounter a subexpression that (1) clearly does not lead to the address 67006de276fff91264437fa75111ed76de43097e089Ted Kremenek/// of a stack variable or (2) is something we cannot determine leads to 67106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// the address of a stack variable based on such local checking. 67206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 673e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek/// EvalAddr processes expressions that are pointers that are used as 674e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek/// references (and not L-values). EvalVal handles all other values. 67506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// At the base case of the recursion is a check for a DeclRefExpr* in 67606de276fff91264437fa75111ed76de43097e089Ted Kremenek/// the refers to a stack variable. 67706de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 67806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// This implementation handles: 67906de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 68006de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * pointer-to-pointer casts 68106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * implicit conversions from array references to pointers 68206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * taking the address of fields 68306de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * arbitrary interplay between "&" and "*" operators 68406de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * pointer arithmetic from an address of a stack variable 68506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * taking the address of an array element where the array is on the stack 68606de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalAddr(Expr *E) { 68706de276fff91264437fa75111ed76de43097e089Ted Kremenek // We should only be called for evaluating pointer expressions. 688fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner assert((E->getType()->isPointerType() || 689a526c5c67e5a0473c340903ee542ce570119665fTed Kremenek E->getType()->isObjCQualifiedIdType()) && 690fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner "EvalAddr only works on pointers"); 69106de276fff91264437fa75111ed76de43097e089Ted Kremenek 69206de276fff91264437fa75111ed76de43097e089Ted Kremenek // Our "symbolic interpreter" is just a dispatch off the currently 69306de276fff91264437fa75111ed76de43097e089Ted Kremenek // viewed AST node. We then recursively traverse the AST by calling 69406de276fff91264437fa75111ed76de43097e089Ted Kremenek // EvalAddr and EvalVal appropriately. 69506de276fff91264437fa75111ed76de43097e089Ted Kremenek switch (E->getStmtClass()) { 696fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ParenExprClass: 697fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Ignore parentheses. 698fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(cast<ParenExpr>(E)->getSubExpr()); 69906de276fff91264437fa75111ed76de43097e089Ted Kremenek 700fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::UnaryOperatorClass: { 701fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // The only unary operator that make sense to handle here 702fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // is AddrOf. All others don't make sense as pointers. 703fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner UnaryOperator *U = cast<UnaryOperator>(E); 70406de276fff91264437fa75111ed76de43097e089Ted Kremenek 705fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (U->getOpcode() == UnaryOperator::AddrOf) 706fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalVal(U->getSubExpr()); 707fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 708fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 709fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 710fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 711fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::BinaryOperatorClass: { 712fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle pointer arithmetic. All other binary operators are not valid 713fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // in this context. 714fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner BinaryOperator *B = cast<BinaryOperator>(E); 715fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner BinaryOperator::Opcode op = B->getOpcode(); 71606de276fff91264437fa75111ed76de43097e089Ted Kremenek 717fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (op != BinaryOperator::Add && op != BinaryOperator::Sub) 718fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 71906de276fff91264437fa75111ed76de43097e089Ted Kremenek 720fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *Base = B->getLHS(); 7213907323dd6665c0c4e383435cb145233f4533406Anders Carlsson 722fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Determine which argument is the real pointer base. It could be 723fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // the RHS argument instead of the LHS. 724fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (!Base->getType()->isPointerType()) Base = B->getRHS(); 72506de276fff91264437fa75111ed76de43097e089Ted Kremenek 726fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner assert (Base->getType()->isPointerType()); 727fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(Base); 728fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 729fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 730fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For conditional operators we need to see if either the LHS or RHS are 731fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // valid DeclRefExpr*s. If one of them is valid, we return it. 732fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ConditionalOperatorClass: { 733fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ConditionalOperator *C = cast<ConditionalOperator>(E); 734fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 735fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle the GNU extension for missing LHS. 736fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (Expr *lhsExpr = C->getLHS()) 737fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (DeclRefExpr* LHS = EvalAddr(lhsExpr)) 738fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return LHS; 73906de276fff91264437fa75111ed76de43097e089Ted Kremenek 740fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(C->getRHS()); 741fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 742fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 743fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For implicit casts, we need to handle conversions from arrays to 744fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // pointer values, and implicit pointer-to-pointer conversions. 745fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ImplicitCastExprClass: { 746fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E); 747fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr* SubExpr = IE->getSubExpr(); 748fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 749fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (SubExpr->getType()->isPointerType() || 750a526c5c67e5a0473c340903ee542ce570119665fTed Kremenek SubExpr->getType()->isObjCQualifiedIdType()) 751fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(SubExpr); 752fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 753fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalVal(SubExpr); 754fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 755fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 756fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For casts, we handle pointer-to-pointer conversions (which 757fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // is essentially a no-op from our mini-interpreter's standpoint). 758fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For other casts we abort. 759fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::CastExprClass: { 760fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CastExpr *C = cast<CastExpr>(E); 761fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *SubExpr = C->getSubExpr(); 762fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 763fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (SubExpr->getType()->isPointerType()) 764fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(SubExpr); 765fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 766fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 767fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 768fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 769fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // C++ casts. For dynamic casts, static casts, and const casts, we 770fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // are always converting from a pointer-to-pointer, so we just blow 771fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // through the cast. In the case the dynamic cast doesn't fail 772fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // (and return NULL), we take the conservative route and report cases 773fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // where we return the address of a stack variable. For Reinterpre 774fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::CXXCastExprClass: { 775fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CXXCastExpr *C = cast<CXXCastExpr>(E); 776fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 777fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (C->getOpcode() == CXXCastExpr::ReinterpretCast) { 778fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *S = C->getSubExpr(); 779fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (S->getType()->isPointerType()) 780fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(S); 78106de276fff91264437fa75111ed76de43097e089Ted Kremenek else 78206de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 78306de276fff91264437fa75111ed76de43097e089Ted Kremenek } 784fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 785fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(C->getSubExpr()); 786fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 787fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 788fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Everything else: we simply don't reason about them. 789fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner default: 790fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 79106de276fff91264437fa75111ed76de43097e089Ted Kremenek } 79206de276fff91264437fa75111ed76de43097e089Ted Kremenek} 79306de276fff91264437fa75111ed76de43097e089Ted Kremenek 79406de276fff91264437fa75111ed76de43097e089Ted Kremenek 79506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// EvalVal - This function is complements EvalAddr in the mutual recursion. 79606de276fff91264437fa75111ed76de43097e089Ted Kremenek/// See the comments for EvalAddr for more details. 79706de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalVal(Expr *E) { 79806de276fff91264437fa75111ed76de43097e089Ted Kremenek 799e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // We should only be called for evaluating non-pointer expressions, or 800e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // expressions with a pointer type that are not used as references but instead 801e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // are l-values (e.g., DeclRefExpr with a pointer type). 802e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek 80306de276fff91264437fa75111ed76de43097e089Ted Kremenek // Our "symbolic interpreter" is just a dispatch off the currently 80406de276fff91264437fa75111ed76de43097e089Ted Kremenek // viewed AST node. We then recursively traverse the AST by calling 80506de276fff91264437fa75111ed76de43097e089Ted Kremenek // EvalAddr and EvalVal appropriately. 80606de276fff91264437fa75111ed76de43097e089Ted Kremenek switch (E->getStmtClass()) { 80706de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::DeclRefExprClass: { 80806de276fff91264437fa75111ed76de43097e089Ted Kremenek // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking 80906de276fff91264437fa75111ed76de43097e089Ted Kremenek // at code that refers to a variable's name. We check if it has local 81006de276fff91264437fa75111ed76de43097e089Ted Kremenek // storage within the function, and if so, return the expression. 81106de276fff91264437fa75111ed76de43097e089Ted Kremenek DeclRefExpr *DR = cast<DeclRefExpr>(E); 81206de276fff91264437fa75111ed76de43097e089Ted Kremenek 81306de276fff91264437fa75111ed76de43097e089Ted Kremenek if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) 81406de276fff91264437fa75111ed76de43097e089Ted Kremenek if(V->hasLocalStorage()) return DR; 81506de276fff91264437fa75111ed76de43097e089Ted Kremenek 81606de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 81706de276fff91264437fa75111ed76de43097e089Ted Kremenek } 81806de276fff91264437fa75111ed76de43097e089Ted Kremenek 81906de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ParenExprClass: 82006de276fff91264437fa75111ed76de43097e089Ted Kremenek // Ignore parentheses. 82106de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalVal(cast<ParenExpr>(E)->getSubExpr()); 82206de276fff91264437fa75111ed76de43097e089Ted Kremenek 82306de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::UnaryOperatorClass: { 82406de276fff91264437fa75111ed76de43097e089Ted Kremenek // The only unary operator that make sense to handle here 82506de276fff91264437fa75111ed76de43097e089Ted Kremenek // is Deref. All others don't resolve to a "name." This includes 82606de276fff91264437fa75111ed76de43097e089Ted Kremenek // handling all sorts of rvalues passed to a unary operator. 82706de276fff91264437fa75111ed76de43097e089Ted Kremenek UnaryOperator *U = cast<UnaryOperator>(E); 82806de276fff91264437fa75111ed76de43097e089Ted Kremenek 82906de276fff91264437fa75111ed76de43097e089Ted Kremenek if (U->getOpcode() == UnaryOperator::Deref) 83006de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalAddr(U->getSubExpr()); 83106de276fff91264437fa75111ed76de43097e089Ted Kremenek 83206de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 83306de276fff91264437fa75111ed76de43097e089Ted Kremenek } 83406de276fff91264437fa75111ed76de43097e089Ted Kremenek 83506de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ArraySubscriptExprClass: { 83606de276fff91264437fa75111ed76de43097e089Ted Kremenek // Array subscripts are potential references to data on the stack. We 83706de276fff91264437fa75111ed76de43097e089Ted Kremenek // retrieve the DeclRefExpr* for the array variable if it indeed 83806de276fff91264437fa75111ed76de43097e089Ted Kremenek // has local storage. 8392324512285caac0332bbbc6e4cab6245d2a370a1Ted Kremenek return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase()); 84006de276fff91264437fa75111ed76de43097e089Ted Kremenek } 84106de276fff91264437fa75111ed76de43097e089Ted Kremenek 84206de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ConditionalOperatorClass: { 84306de276fff91264437fa75111ed76de43097e089Ted Kremenek // For conditional operators we need to see if either the LHS or RHS are 84406de276fff91264437fa75111ed76de43097e089Ted Kremenek // non-NULL DeclRefExpr's. If one is non-NULL, we return it. 84506de276fff91264437fa75111ed76de43097e089Ted Kremenek ConditionalOperator *C = cast<ConditionalOperator>(E); 84606de276fff91264437fa75111ed76de43097e089Ted Kremenek 8473907323dd6665c0c4e383435cb145233f4533406Anders Carlsson // Handle the GNU extension for missing LHS. 8483907323dd6665c0c4e383435cb145233f4533406Anders Carlsson if (Expr *lhsExpr = C->getLHS()) 8493907323dd6665c0c4e383435cb145233f4533406Anders Carlsson if (DeclRefExpr *LHS = EvalVal(lhsExpr)) 8503907323dd6665c0c4e383435cb145233f4533406Anders Carlsson return LHS; 8513907323dd6665c0c4e383435cb145233f4533406Anders Carlsson 8523907323dd6665c0c4e383435cb145233f4533406Anders Carlsson return EvalVal(C->getRHS()); 85306de276fff91264437fa75111ed76de43097e089Ted Kremenek } 85406de276fff91264437fa75111ed76de43097e089Ted Kremenek 85506de276fff91264437fa75111ed76de43097e089Ted Kremenek // Accesses to members are potential references to data on the stack. 85606de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::MemberExprClass: { 85706de276fff91264437fa75111ed76de43097e089Ted Kremenek MemberExpr *M = cast<MemberExpr>(E); 85806de276fff91264437fa75111ed76de43097e089Ted Kremenek 85906de276fff91264437fa75111ed76de43097e089Ted Kremenek // Check for indirect access. We only want direct field accesses. 86006de276fff91264437fa75111ed76de43097e089Ted Kremenek if (!M->isArrow()) 86106de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalVal(M->getBase()); 86206de276fff91264437fa75111ed76de43097e089Ted Kremenek else 86306de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 86406de276fff91264437fa75111ed76de43097e089Ted Kremenek } 86506de276fff91264437fa75111ed76de43097e089Ted Kremenek 86606de276fff91264437fa75111ed76de43097e089Ted Kremenek // Everything else: we simply don't reason about them. 86706de276fff91264437fa75111ed76de43097e089Ted Kremenek default: 86806de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 86906de276fff91264437fa75111ed76de43097e089Ted Kremenek } 87006de276fff91264437fa75111ed76de43097e089Ted Kremenek} 871588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 872588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===// 873588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 874588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// Check for comparisons of floating point operands using != and ==. 875588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// Issue a warning if these are no self-comparisons, as they are not likely 876588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// to do what the programmer intended. 877588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenekvoid Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) { 878588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek bool EmitWarning = true; 879588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 8804e99a5fc3b203397a91136c6e695e405fb8fc606Ted Kremenek Expr* LeftExprSansParen = lex->IgnoreParens(); 88132e97b66bbce16c9e81c877794fb7a0aeeb66ccbTed Kremenek Expr* RightExprSansParen = rex->IgnoreParens(); 882588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 883588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Special case: check for x == x (which is OK). 884588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Do not emit warnings for such cases. 885588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen)) 886588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen)) 887588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DRL->getDecl() == DRR->getDecl()) 888588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 889588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 8901b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek 8911b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // Special case: check for comparisons against literals that can be exactly 8921b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // represented by APFloat. In such cases, do not emit a warning. This 8931b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // is a heuristic: often comparison against such literals are used to 8941b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // detect if a value in a variable has not changed. This clearly can 8951b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // lead to false negatives. 8961b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (EmitWarning) { 8971b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) { 8981b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FLL->isExact()) 8991b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek EmitWarning = false; 9001b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9011b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek else 9021b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){ 9031b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FLR->isExact()) 9041b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek EmitWarning = false; 9051b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9061b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9071b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek 908588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Check for comparisons with builtin types. 909588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 910588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen)) 911588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (isCallBuiltin(CL)) 912588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 913588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 914588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 915588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen)) 916588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (isCallBuiltin(CR)) 917588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 918588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 919588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Emit the diagnostic. 920588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 921588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek Diag(loc, diag::warn_floatingpoint_eq, 922588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek lex->getSourceRange(),rex->getSourceRange()); 923588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek} 924