SemaChecking.cpp revision dd972f20dc2bd3609d833893e5c6544ac09b59a9
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" 17c4a1dea2dc56bd1357ec91b829a0b9e68229a13eDaniel Dunbar#include "clang/AST/DeclObjC.h" 182324512285caac0332bbbc6e4cab6245d2a370a1Ted Kremenek#include "clang/AST/ExprCXX.h" 197ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek#include "clang/AST/ExprObjC.h" 2059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Lex/Preprocessor.h" 2159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Basic/Diagnostic.h" 22588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek#include "SemaUtil.h" 2359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattnerusing namespace clang; 2459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 2559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// CheckFunctionCall - Check a direct function call for various correctness 2659907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// and safety properties not strictly enforced by the C type system. 27d38617c8a50f9729c254ab76cd359af797c6739bEli FriedmanAction::ExprResult 28e801870b638e47a5734a3ea63ddfb45f1711e078Eli FriedmanSema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCallRaw) { 29e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman llvm::OwningPtr<CallExpr> TheCall(TheCallRaw); 3059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // Get the IdentifierInfo* for the called function. 3159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner IdentifierInfo *FnInfo = FDecl->getIdentifier(); 3259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 3330ce344307f8a8b00054021307015571f83c7364Chris Lattner switch (FnInfo->getBuiltinID()) { 3430ce344307f8a8b00054021307015571f83c7364Chris Lattner case Builtin::BI__builtin___CFStringMakeConstantString: 35925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner assert(TheCall->getNumArgs() == 1 && 361b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner "Wrong # arguments to builtin CFStringMakeConstantString"); 37e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (CheckBuiltinCFStringArgument(TheCall->getArg(0))) 38d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 39e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 4049ff7a1c8c67d56e62d3b4627463b705c0d5008cTed Kremenek case Builtin::BI__builtin_stdarg_start: 4130ce344307f8a8b00054021307015571f83c7364Chris Lattner case Builtin::BI__builtin_va_start: 42b7cfe88e88cb4f46308de89cf3f0c81bfe624128Chris Lattner if (SemaBuiltinVAStart(TheCall.get())) 43d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 44e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 451b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isgreater: 461b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isgreaterequal: 471b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isless: 481b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_islessequal: 491b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_islessgreater: 501b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isunordered: 51e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (SemaBuiltinUnorderedCompare(TheCall.get())) 52d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 53e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 546cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman case Builtin::BI__builtin_return_address: 556cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman case Builtin::BI__builtin_frame_address: 566cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman if (SemaBuiltinStackAddress(TheCall.get())) 576cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return true; 586cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return TheCall.take(); 59d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman case Builtin::BI__builtin_shufflevector: 60e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return SemaBuiltinShuffleVector(TheCall.get()); 614493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar case Builtin::BI__builtin_prefetch: 624493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (SemaBuiltinPrefetch(TheCall.get())) 634493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar return true; 644493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar return TheCall.take(); 65d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar case Builtin::BI__builtin_object_size: 66d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar if (SemaBuiltinObjectSize(TheCall.get())) 67d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar return true; 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; 222d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner if (!TheCall->getArg(0)->isIntegerConstantExpr(Context, &Loc)) 2236cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return Diag(Loc, diag::err_stack_const_level, TheCall->getSourceRange()); 224d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner 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 245b77792eabf5882cf9af8cc810599b20432fda6c2Chris Lattner if (Context.getCanonicalType(FAType).getUnqualifiedType() != 246b77792eabf5882cf9af8cc810599b20432fda6c2Chris Lattner Context.getCanonicalType(SAType).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) 256d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args, 257d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner TheCall->getSourceRange()); 258d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_many_args, 259d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner TheCall->getSourceRange()); 260d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 261d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 262d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman for (unsigned i = 2; i < TheCall->getNumArgs(); i++) { 263d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman llvm::APSInt Result(32); 264d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context)) 265d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner return Diag(TheCall->getLocStart(), 266d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner diag::err_shufflevector_nonconstant_argument, 267d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner TheCall->getArg(i)->getSourceRange()); 268d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner 269d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2) 270d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner return Diag(TheCall->getLocStart(), 271d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner diag::err_shufflevector_argument_too_large, 272d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner TheCall->getArg(i)->getSourceRange()); 273d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 274d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 275d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman llvm::SmallVector<Expr*, 32> exprs; 276d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 277d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) { 278d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman exprs.push_back(TheCall->getArg(i)); 279d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->setArg(i, 0); 280d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 281d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 282d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner return new ShuffleVectorExpr(exprs.begin(), numElements+2, FAType, 283d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner TheCall->getCallee()->getLocStart(), 284d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner TheCall->getRParenLoc()); 285d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman} 28630ce344307f8a8b00054021307015571f83c7364Chris Lattner 2874493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar/// SemaBuiltinPrefetch - Handle __builtin_prefetch. 2884493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar// This is declared to take (const void*, ...) and can take two 2894493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar// optional constant int args. 2904493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbarbool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) { 2914493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar unsigned numArgs = TheCall->getNumArgs(); 2924493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar bool res = false; 2934493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 2944493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (numArgs > 3) { 2954493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar res |= Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_many_args, 2964493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar TheCall->getSourceRange()); 2974493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 2984493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 2994493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // Argument 0 is checked for us and the remaining arguments must be 3004493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // constant integers. 3014493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar for (unsigned i=1; i<numArgs; ++i) { 3024493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar Expr *Arg = TheCall->getArg(i); 3034493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar QualType RWType = Arg->getType(); 3044493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3054493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar const BuiltinType *BT = RWType->getAsBuiltinType(); 306d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar llvm::APSInt Result; 3074493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (!BT || BT->getKind() != BuiltinType::Int || 3084493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar !Arg->isIntegerConstantExpr(Result, Context)) { 3094493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (Diag(TheCall->getLocStart(), diag::err_prefetch_invalid_argument, 3104493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar SourceRange(Arg->getLocStart(), Arg->getLocEnd()))) { 3114493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar res = true; 3124493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar continue; 3134493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3144493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3154493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3164493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // FIXME: gcc issues a warning and rewrites these to 0. These 3174493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // seems especially odd for the third argument since the default 3184493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // is 3. 3194493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (i==1) { 3204493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (Result.getSExtValue() < 0 || Result.getSExtValue() > 1) 321d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar res |= Diag(TheCall->getLocStart(), diag::err_argument_invalid_range, 3224493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar "0", "1", 3234493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar SourceRange(Arg->getLocStart(), Arg->getLocEnd())); 3244493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } else { 3254493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) 326d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar res |= Diag(TheCall->getLocStart(), diag::err_argument_invalid_range, 3274493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar "0", "3", 3284493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar SourceRange(Arg->getLocStart(), Arg->getLocEnd())); 3294493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3304493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3314493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3324493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar return res; 3334493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar} 3344493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 335d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar/// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr, 336d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar/// int type). This simply type checks that type is one of the defined 337d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar/// constants (0-3). 338d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbarbool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) { 339d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar Expr *Arg = TheCall->getArg(1); 340d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar QualType ArgType = Arg->getType(); 341d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar const BuiltinType *BT = ArgType->getAsBuiltinType(); 342d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar llvm::APSInt Result(32); 343d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar if (!BT || BT->getKind() != BuiltinType::Int || 344d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar !Arg->isIntegerConstantExpr(Result, Context)) { 345d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar return Diag(TheCall->getLocStart(), diag::err_object_size_invalid_argument, 346d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar SourceRange(Arg->getLocStart(), Arg->getLocEnd())); 347d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar } 348d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar 349d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) { 350d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range, 351d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar "0", "3", 352d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar SourceRange(Arg->getLocStart(), Arg->getLocEnd())); 353d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar } 354d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar 355d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar return false; 356d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar} 357d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar 35859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// CheckPrintfArguments - Check calls to printf (and similar functions) for 35971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// correct use of format strings. 36071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 36171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// HasVAListArg - A predicate indicating whether the printf-like 36271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// function is passed an explicit va_arg argument (e.g., vprintf) 36371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 36471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// format_idx - The index into Args for the format string. 36571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 36671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Improper format strings to functions in the printf family can be 36771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// the source of bizarre bugs and very serious security holes. A 36871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// good source of information is available in the following paper 36971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (which includes additional references): 37059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// 37159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// FormatGuard: Automatic Protection From printf Format String 37259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// Vulnerabilities, Proceedings of the 10th USENIX Security Symposium, 2001. 37371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 37471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Functionality implemented: 37571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 37671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// We can statically check the following properties for string 37771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// literal format strings for non v.*printf functions (where the 37871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// arguments are passed directly): 37971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek// 38071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (1) Are the number of format conversions equal to the number of 38171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// data arguments? 38271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 38371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (2) Does each format conversion correctly match the type of the 38471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// corresponding data argument? (TODO) 38571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 38671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Moreover, for all printf functions we can: 38771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 38871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (3) Check for a missing format string (when not caught by type checking). 38971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (4) Check for no-operation flags; e.g. using "#" with format 39171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// conversion 'c' (TODO) 39271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (5) Check the use of '%n', a major source of security holes. 39471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (6) Check for malformed format conversions that don't specify anything. 39671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (7) Check for empty format strings. e.g: printf(""); 39871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (8) Check that the format string is a wide literal. 40071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 4016d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// (9) Also check the arguments of functions with the __format__ attribute. 4026d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// (TODO). 4036d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// 40471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// All of these checks can be done by parsing the format string. 40571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 40671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// For now, we ONLY do (1), (3), (5), (6), (7), and (8). 40759907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattnervoid 408925e60d3fa706f31886027c876989af79eb0e0d2Chris LattnerSema::CheckPrintfArguments(CallExpr *TheCall, bool HasVAListArg, 409925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner unsigned format_idx) { 410925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *Fn = TheCall->getCallee(); 411925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner 41271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: printf-like function is called with no format string. 413925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (format_idx >= TheCall->getNumArgs()) { 414925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getRParenLoc(), diag::warn_printf_missing_format_string, 41571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Fn->getSourceRange()); 41671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 41771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 41871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 41956f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts(); 420459e8488046be5df0bf57f0a8677316abf253167Chris Lattner 42159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // CHECK: format string is not a string literal. 42259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // 42371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Dynamically generated format strings are difficult to 42471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // automatically vet at compile time. Requiring that format strings 42571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // are string literals: (1) permits the checking of format strings by 42671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // the compiler and thereby (2) can practically remove the source of 42771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // many format string exploits. 4287ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 4297ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Format string can be either ObjC string (e.g. @"%d") or 4307ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // C string (e.g. "%d") 4317ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // ObjC string uses the same format specifiers as C string, so we can use 4327ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // the same format string checking logic for both ObjC and C strings. 4337ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(OrigFormatExpr); 4347ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek StringLiteral *FExpr = NULL; 4357ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 4367ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek if(ObjCFExpr != NULL) 4377ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek FExpr = ObjCFExpr->getString(); 4387ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek else 4397ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek FExpr = dyn_cast<StringLiteral>(OrigFormatExpr); 4407ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 44171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (FExpr == NULL) { 4424a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // For vprintf* functions (i.e., HasVAListArg==true), we add a 4434a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // special check to see if the format string is a function parameter 4444a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // of the function calling the printf function. If the function 4454a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // has an attribute indicating it is a printf-like function, then we 4464a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // should suppress warnings concerning non-literals being used in a call 4474a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // to a vprintf function. For example: 4484a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 4494a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // void 4504a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...) { 4514a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // va_list ap; 4524a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // va_start(ap, fmt); 4534a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // vprintf(fmt, ap); // Do NOT emit a warning about "fmt". 4544a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // ... 4554a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 4564a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 4574a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // FIXME: We don't have full attribute support yet, so just check to see 4584a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // if the argument is a DeclRefExpr that references a parameter. We'll 4594a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // add proper support for checking the attribute later. 4604a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek if (HasVAListArg) 461998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner if (DeclRefExpr* DR = dyn_cast<DeclRefExpr>(OrigFormatExpr)) 462998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner if (isa<ParmVarDecl>(DR->getDecl())) 4634a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek return; 4644a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek 465925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(format_idx)->getLocStart(), 4669801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek diag::warn_printf_not_string_constant, 4679801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 46871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 46971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 47071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 47171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: is the format string a wide literal? 47271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (FExpr->isWide()) { 473925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(FExpr->getLocStart(), 4749801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek diag::warn_printf_format_string_is_wide_literal, 4759801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 47671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 47771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 47871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 47971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Str - The format string. NOTE: this is NOT null-terminated! 48071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek const char * const Str = FExpr->getStrData(); 48171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 48271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: empty format string? 48371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek const unsigned StrLen = FExpr->getByteLength(); 48471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 48571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (StrLen == 0) { 486925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(FExpr->getLocStart(), diag::warn_printf_empty_format_string, 4879801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 48871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 48971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 49071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 49171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // We process the format string using a binary state machine. The 49271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // current state is stored in CurrentState. 49371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek enum { 49471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek state_OrdChr, 49571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek state_Conversion 49671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } CurrentState = state_OrdChr; 49771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 49871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // numConversions - The number of conversions seen so far. This is 49971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // incremented as we traverse the format string. 50071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned numConversions = 0; 50171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 50271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // numDataArgs - The number of data arguments after the format 50371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // string. This can only be determined for non vprintf-like 50471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // functions. For those functions, this value is 1 (the sole 50571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // va_arg argument). 506925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner unsigned numDataArgs = TheCall->getNumArgs()-(format_idx+1); 50771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 50871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Inspect the format string. 50971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned StrIdx = 0; 51071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 51171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // LastConversionIdx - Index within the format string where we last saw 51271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // a '%' character that starts a new format conversion. 51371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned LastConversionIdx = 0; 51471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 515925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner for (; StrIdx < StrLen; ++StrIdx) { 516998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner 51771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Is the number of detected conversion conversions greater than 51871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // the number of matching data arguments? If so, stop. 51971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (!HasVAListArg && numConversions > numDataArgs) break; 52071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 52171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Handle "\0" 522925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (Str[StrIdx] == '\0') { 52371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // The string returned by getStrData() is not null-terminated, 52471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // so the presence of a null character is likely an error. 525998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner Diag(PP.AdvanceToTokenCharacter(FExpr->getLocStart(), StrIdx+1), 526998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner diag::warn_printf_format_string_contains_null_char, 5279801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 52871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 52971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 53071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 53171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Ordinary characters (not processing a format conversion). 53271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (CurrentState == state_OrdChr) { 53371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (Str[StrIdx] == '%') { 53471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek CurrentState = state_Conversion; 53571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek LastConversionIdx = StrIdx; 53671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 53771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek continue; 53871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 53971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 54071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Seen '%'. Now processing a format conversion. 54171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek switch (Str[StrIdx]) { 542fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle dynamic precision or width specifier. 543fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case '*': { 544fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 545fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 546fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (!HasVAListArg && numConversions > numDataArgs) { 547fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = FExpr->getLocStart(); 548fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Loc = PP.AdvanceToTokenCharacter(Loc, StrIdx+1); 549580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek 550580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek if (Str[StrIdx-1] == '.') 551fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_precision_missing_arg, 5529801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 553580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek else 554fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_width_missing_arg, 5559801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 556580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek 557fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Don't do any more checking. We'll just emit spurious errors. 558fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return; 559580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek } 560fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 561fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Perform type checking on width/precision specifier. 562fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *E = TheCall->getArg(format_idx+numConversions); 563fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (const BuiltinType *BT = E->getType()->getAsBuiltinType()) 564fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (BT->getKind() == BuiltinType::Int) 565fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 566fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 567fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = 568fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner PP.AdvanceToTokenCharacter(FExpr->getLocStart(), StrIdx+1); 569fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 570fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (Str[StrIdx-1] == '.') 571fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_precision_wrong_type, 572fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner E->getType().getAsString(), E->getSourceRange()); 573fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 574fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_width_wrong_type, 575fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner E->getType().getAsString(), E->getSourceRange()); 576fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 577fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 578fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 579fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 580fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Characters which can terminate a format conversion 581fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // (e.g. "%d"). Characters that specify length modifiers or 582fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // other flags are handled by the default case below. 583fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // 584fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // FIXME: additional checks will go into the following cases. 585fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'i': 586fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'd': 587fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'o': 588fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'u': 589fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'x': 590fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'X': 591fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'D': 592fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'O': 593fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'U': 594fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'e': 595fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'E': 596fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'f': 597fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'F': 598fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'g': 599fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'G': 600fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'a': 601fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'A': 602fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'c': 603fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'C': 604fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'S': 605fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 's': 606fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'p': 607fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 608fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 609fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 61071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 611fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // CHECK: Are we using "%n"? Issue a warning. 612fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'n': { 613fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 614fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 615fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 616fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner LastConversionIdx+1); 617fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 6189801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek Diag(Loc, diag::warn_printf_write_back, OrigFormatExpr->getSourceRange()); 619fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 620fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 6217ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 6227ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Handle "%@" 6237ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek case '@': 6247ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // %@ is allowed in ObjC format strings only. 6257ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek if(ObjCFExpr != NULL) 6267ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek CurrentState = state_OrdChr; 6277ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek else { 6287ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Issue a warning: invalid format conversion. 6297ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 6307ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek LastConversionIdx+1); 6317ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 6327ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek Diag(Loc, diag::warn_printf_invalid_conversion, 6337ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek std::string(Str+LastConversionIdx, 6347ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek Str+std::min(LastConversionIdx+2, StrLen)), 6359801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 6367ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek } 6377ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek ++numConversions; 6387ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek break; 6397ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 640fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle "%%" 641fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case '%': 642fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Sanity check: Was the first "%" character the previous one? 643fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // If not, we will assume that we have a malformed format 644fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // conversion, and that the current "%" character is the start 645fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // of a new conversion. 646fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (StrIdx - LastConversionIdx == 1) 647fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 648fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else { 649fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Issue a warning: invalid format conversion. 650925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 651925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx+1); 652fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 653fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_invalid_conversion, 654fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner std::string(Str+LastConversionIdx, Str+StrIdx), 6559801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 656fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 657fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // This conversion is broken. Advance to the next format 658fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // conversion. 659fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner LastConversionIdx = StrIdx; 660fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 66171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 662fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 66371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 664fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner default: 665fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // This case catches all other characters: flags, widths, etc. 666fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // We should eventually process those as well. 667fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 66871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 66971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 67071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 67171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (CurrentState == state_Conversion) { 67271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Issue a warning: invalid format conversion. 673925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 674925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx+1); 67571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 67671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Diag(Loc, diag::warn_printf_invalid_conversion, 677a9e2ea107d9419a6406f01e513679327032da193Chris Lattner std::string(Str+LastConversionIdx, 678a9e2ea107d9419a6406f01e513679327032da193Chris Lattner Str+std::min(LastConversionIdx+2, StrLen)), 6799801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 68071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 68171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 68271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 68371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (!HasVAListArg) { 68471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: Does the number of format conversions exceed the number 68571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // of data arguments? 68671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (numConversions > numDataArgs) { 687925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 688925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx); 68971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 69071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Diag(Loc, diag::warn_printf_insufficient_data_args, 6919801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 69271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 69371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: Does the number of data arguments exceed the number of 69471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // format conversions in the format string? 69571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek else if (numConversions < numDataArgs) 696925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(format_idx+numConversions+1)->getLocStart(), 6979801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek diag::warn_printf_too_many_data_args, 6989801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 69971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 70071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek} 70106de276fff91264437fa75111ed76de43097e089Ted Kremenek 70206de276fff91264437fa75111ed76de43097e089Ted Kremenek//===--- CHECK: Return Address of Stack Variable --------------------------===// 70306de276fff91264437fa75111ed76de43097e089Ted Kremenek 70406de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalVal(Expr *E); 70506de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalAddr(Expr* E); 70606de276fff91264437fa75111ed76de43097e089Ted Kremenek 70706de276fff91264437fa75111ed76de43097e089Ted Kremenek/// CheckReturnStackAddr - Check if a return statement returns the address 70806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// of a stack variable. 70906de276fff91264437fa75111ed76de43097e089Ted Kremenekvoid 71006de276fff91264437fa75111ed76de43097e089Ted KremenekSema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType, 71106de276fff91264437fa75111ed76de43097e089Ted Kremenek SourceLocation ReturnLoc) { 71256f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner 71306de276fff91264437fa75111ed76de43097e089Ted Kremenek // Perform checking for returned stack addresses. 714dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff if (lhsType->isPointerType() || lhsType->isBlockPointerType()) { 71506de276fff91264437fa75111ed76de43097e089Ted Kremenek if (DeclRefExpr *DR = EvalAddr(RetValExp)) 71606de276fff91264437fa75111ed76de43097e089Ted Kremenek Diag(DR->getLocStart(), diag::warn_ret_stack_addr, 71706de276fff91264437fa75111ed76de43097e089Ted Kremenek DR->getDecl()->getIdentifier()->getName(), 71806de276fff91264437fa75111ed76de43097e089Ted Kremenek RetValExp->getSourceRange()); 719dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff 720dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff if (BlockExpr *C = dyn_cast_or_null<BlockExpr>(EvalAddr(RetValExp))) 721dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff Diag(C->getLocStart(), diag::err_ret_local_block, 722dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff C->getSourceRange()); 72306de276fff91264437fa75111ed76de43097e089Ted Kremenek } 72406de276fff91264437fa75111ed76de43097e089Ted Kremenek // Perform checking for stack values returned by reference. 72506de276fff91264437fa75111ed76de43097e089Ted Kremenek else if (lhsType->isReferenceType()) { 72696eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek // Check for an implicit cast to a reference. 72796eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek if (ImplicitCastExpr *I = dyn_cast<ImplicitCastExpr>(RetValExp)) 72896eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek if (DeclRefExpr *DR = EvalVal(I->getSubExpr())) 72996eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek Diag(DR->getLocStart(), diag::warn_ret_stack_ref, 73096eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek DR->getDecl()->getIdentifier()->getName(), 73196eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek RetValExp->getSourceRange()); 73206de276fff91264437fa75111ed76de43097e089Ted Kremenek } 73306de276fff91264437fa75111ed76de43097e089Ted Kremenek} 73406de276fff91264437fa75111ed76de43097e089Ted Kremenek 73506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that 73606de276fff91264437fa75111ed76de43097e089Ted Kremenek/// check if the expression in a return statement evaluates to an address 73706de276fff91264437fa75111ed76de43097e089Ted Kremenek/// to a location on the stack. The recursion is used to traverse the 73806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// AST of the return expression, with recursion backtracking when we 73906de276fff91264437fa75111ed76de43097e089Ted Kremenek/// encounter a subexpression that (1) clearly does not lead to the address 74006de276fff91264437fa75111ed76de43097e089Ted Kremenek/// of a stack variable or (2) is something we cannot determine leads to 74106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// the address of a stack variable based on such local checking. 74206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 743e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek/// EvalAddr processes expressions that are pointers that are used as 744e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek/// references (and not L-values). EvalVal handles all other values. 74506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// At the base case of the recursion is a check for a DeclRefExpr* in 74606de276fff91264437fa75111ed76de43097e089Ted Kremenek/// the refers to a stack variable. 74706de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 74806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// This implementation handles: 74906de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 75006de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * pointer-to-pointer casts 75106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * implicit conversions from array references to pointers 75206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * taking the address of fields 75306de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * arbitrary interplay between "&" and "*" operators 75406de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * pointer arithmetic from an address of a stack variable 75506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * taking the address of an array element where the array is on the stack 75606de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalAddr(Expr *E) { 75706de276fff91264437fa75111ed76de43097e089Ted Kremenek // We should only be called for evaluating pointer expressions. 758dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff assert((E->getType()->isPointerType() || 759dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff E->getType()->isBlockPointerType() || 760a526c5c67e5a0473c340903ee542ce570119665fTed Kremenek E->getType()->isObjCQualifiedIdType()) && 761fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner "EvalAddr only works on pointers"); 76206de276fff91264437fa75111ed76de43097e089Ted Kremenek 76306de276fff91264437fa75111ed76de43097e089Ted Kremenek // Our "symbolic interpreter" is just a dispatch off the currently 76406de276fff91264437fa75111ed76de43097e089Ted Kremenek // viewed AST node. We then recursively traverse the AST by calling 76506de276fff91264437fa75111ed76de43097e089Ted Kremenek // EvalAddr and EvalVal appropriately. 76606de276fff91264437fa75111ed76de43097e089Ted Kremenek switch (E->getStmtClass()) { 767fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ParenExprClass: 768fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Ignore parentheses. 769fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(cast<ParenExpr>(E)->getSubExpr()); 77006de276fff91264437fa75111ed76de43097e089Ted Kremenek 771fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::UnaryOperatorClass: { 772fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // The only unary operator that make sense to handle here 773fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // is AddrOf. All others don't make sense as pointers. 774fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner UnaryOperator *U = cast<UnaryOperator>(E); 77506de276fff91264437fa75111ed76de43097e089Ted Kremenek 776fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (U->getOpcode() == UnaryOperator::AddrOf) 777fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalVal(U->getSubExpr()); 778fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 779fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 780fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 781fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 782fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::BinaryOperatorClass: { 783fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle pointer arithmetic. All other binary operators are not valid 784fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // in this context. 785fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner BinaryOperator *B = cast<BinaryOperator>(E); 786fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner BinaryOperator::Opcode op = B->getOpcode(); 78706de276fff91264437fa75111ed76de43097e089Ted Kremenek 788fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (op != BinaryOperator::Add && op != BinaryOperator::Sub) 789fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 79006de276fff91264437fa75111ed76de43097e089Ted Kremenek 791fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *Base = B->getLHS(); 7923907323dd6665c0c4e383435cb145233f4533406Anders Carlsson 793fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Determine which argument is the real pointer base. It could be 794fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // the RHS argument instead of the LHS. 795fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (!Base->getType()->isPointerType()) Base = B->getRHS(); 79606de276fff91264437fa75111ed76de43097e089Ted Kremenek 797fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner assert (Base->getType()->isPointerType()); 798fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(Base); 799fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 800fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 801fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For conditional operators we need to see if either the LHS or RHS are 802fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // valid DeclRefExpr*s. If one of them is valid, we return it. 803fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ConditionalOperatorClass: { 804fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ConditionalOperator *C = cast<ConditionalOperator>(E); 805fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 806fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle the GNU extension for missing LHS. 807fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (Expr *lhsExpr = C->getLHS()) 808fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (DeclRefExpr* LHS = EvalAddr(lhsExpr)) 809fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return LHS; 81006de276fff91264437fa75111ed76de43097e089Ted Kremenek 811fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(C->getRHS()); 812fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 813fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 81454b5274f2c190331438375ad114dad12ae098b57Ted Kremenek // For casts, we need to handle conversions from arrays to 81554b5274f2c190331438375ad114dad12ae098b57Ted Kremenek // pointer values, and pointer-to-pointer conversions. 8160835a3cdeefe714b4959d31127ea155e56393125Argyrios Kyrtzidis case Stmt::ExplicitCastExprClass: 817fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ImplicitCastExprClass: { 818fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 8190835a3cdeefe714b4959d31127ea155e56393125Argyrios Kyrtzidis Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 82054b5274f2c190331438375ad114dad12ae098b57Ted Kremenek QualType T = SubExpr->getType(); 821fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 822dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff if (SubExpr->getType()->isPointerType() || 823dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff SubExpr->getType()->isBlockPointerType() || 824dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff SubExpr->getType()->isObjCQualifiedIdType()) 825fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(SubExpr); 82654b5274f2c190331438375ad114dad12ae098b57Ted Kremenek else if (T->isArrayType()) 82754b5274f2c190331438375ad114dad12ae098b57Ted Kremenek return EvalVal(SubExpr); 828fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 82954b5274f2c190331438375ad114dad12ae098b57Ted Kremenek return 0; 830fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 831fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 832fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // C++ casts. For dynamic casts, static casts, and const casts, we 833fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // are always converting from a pointer-to-pointer, so we just blow 834fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // through the cast. In the case the dynamic cast doesn't fail 835fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // (and return NULL), we take the conservative route and report cases 836fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // where we return the address of a stack variable. For Reinterpre 837fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::CXXCastExprClass: { 838fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CXXCastExpr *C = cast<CXXCastExpr>(E); 839fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 840fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (C->getOpcode() == CXXCastExpr::ReinterpretCast) { 841fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *S = C->getSubExpr(); 842dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff if (S->getType()->isPointerType() || S->getType()->isBlockPointerType()) 843fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(S); 84406de276fff91264437fa75111ed76de43097e089Ted Kremenek else 84506de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 84606de276fff91264437fa75111ed76de43097e089Ted Kremenek } 847fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 848fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(C->getSubExpr()); 849fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 850fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 851fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Everything else: we simply don't reason about them. 852fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner default: 853fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 85406de276fff91264437fa75111ed76de43097e089Ted Kremenek } 85506de276fff91264437fa75111ed76de43097e089Ted Kremenek} 85606de276fff91264437fa75111ed76de43097e089Ted Kremenek 85706de276fff91264437fa75111ed76de43097e089Ted Kremenek 85806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// EvalVal - This function is complements EvalAddr in the mutual recursion. 85906de276fff91264437fa75111ed76de43097e089Ted Kremenek/// See the comments for EvalAddr for more details. 86006de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalVal(Expr *E) { 86106de276fff91264437fa75111ed76de43097e089Ted Kremenek 862e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // We should only be called for evaluating non-pointer expressions, or 863e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // expressions with a pointer type that are not used as references but instead 864e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // are l-values (e.g., DeclRefExpr with a pointer type). 865e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek 86606de276fff91264437fa75111ed76de43097e089Ted Kremenek // Our "symbolic interpreter" is just a dispatch off the currently 86706de276fff91264437fa75111ed76de43097e089Ted Kremenek // viewed AST node. We then recursively traverse the AST by calling 86806de276fff91264437fa75111ed76de43097e089Ted Kremenek // EvalAddr and EvalVal appropriately. 86906de276fff91264437fa75111ed76de43097e089Ted Kremenek switch (E->getStmtClass()) { 87006de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::DeclRefExprClass: { 87106de276fff91264437fa75111ed76de43097e089Ted Kremenek // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking 87206de276fff91264437fa75111ed76de43097e089Ted Kremenek // at code that refers to a variable's name. We check if it has local 87306de276fff91264437fa75111ed76de43097e089Ted Kremenek // storage within the function, and if so, return the expression. 87406de276fff91264437fa75111ed76de43097e089Ted Kremenek DeclRefExpr *DR = cast<DeclRefExpr>(E); 87506de276fff91264437fa75111ed76de43097e089Ted Kremenek 87606de276fff91264437fa75111ed76de43097e089Ted Kremenek if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) 87706de276fff91264437fa75111ed76de43097e089Ted Kremenek if(V->hasLocalStorage()) return DR; 87806de276fff91264437fa75111ed76de43097e089Ted Kremenek 87906de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 88006de276fff91264437fa75111ed76de43097e089Ted Kremenek } 88106de276fff91264437fa75111ed76de43097e089Ted Kremenek 88206de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ParenExprClass: 88306de276fff91264437fa75111ed76de43097e089Ted Kremenek // Ignore parentheses. 88406de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalVal(cast<ParenExpr>(E)->getSubExpr()); 88506de276fff91264437fa75111ed76de43097e089Ted Kremenek 88606de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::UnaryOperatorClass: { 88706de276fff91264437fa75111ed76de43097e089Ted Kremenek // The only unary operator that make sense to handle here 88806de276fff91264437fa75111ed76de43097e089Ted Kremenek // is Deref. All others don't resolve to a "name." This includes 88906de276fff91264437fa75111ed76de43097e089Ted Kremenek // handling all sorts of rvalues passed to a unary operator. 89006de276fff91264437fa75111ed76de43097e089Ted Kremenek UnaryOperator *U = cast<UnaryOperator>(E); 89106de276fff91264437fa75111ed76de43097e089Ted Kremenek 89206de276fff91264437fa75111ed76de43097e089Ted Kremenek if (U->getOpcode() == UnaryOperator::Deref) 89306de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalAddr(U->getSubExpr()); 89406de276fff91264437fa75111ed76de43097e089Ted Kremenek 89506de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 89606de276fff91264437fa75111ed76de43097e089Ted Kremenek } 89706de276fff91264437fa75111ed76de43097e089Ted Kremenek 89806de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ArraySubscriptExprClass: { 89906de276fff91264437fa75111ed76de43097e089Ted Kremenek // Array subscripts are potential references to data on the stack. We 90006de276fff91264437fa75111ed76de43097e089Ted Kremenek // retrieve the DeclRefExpr* for the array variable if it indeed 90106de276fff91264437fa75111ed76de43097e089Ted Kremenek // has local storage. 9022324512285caac0332bbbc6e4cab6245d2a370a1Ted Kremenek return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase()); 90306de276fff91264437fa75111ed76de43097e089Ted Kremenek } 90406de276fff91264437fa75111ed76de43097e089Ted Kremenek 90506de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ConditionalOperatorClass: { 90606de276fff91264437fa75111ed76de43097e089Ted Kremenek // For conditional operators we need to see if either the LHS or RHS are 90706de276fff91264437fa75111ed76de43097e089Ted Kremenek // non-NULL DeclRefExpr's. If one is non-NULL, we return it. 90806de276fff91264437fa75111ed76de43097e089Ted Kremenek ConditionalOperator *C = cast<ConditionalOperator>(E); 90906de276fff91264437fa75111ed76de43097e089Ted Kremenek 9103907323dd6665c0c4e383435cb145233f4533406Anders Carlsson // Handle the GNU extension for missing LHS. 9113907323dd6665c0c4e383435cb145233f4533406Anders Carlsson if (Expr *lhsExpr = C->getLHS()) 9123907323dd6665c0c4e383435cb145233f4533406Anders Carlsson if (DeclRefExpr *LHS = EvalVal(lhsExpr)) 9133907323dd6665c0c4e383435cb145233f4533406Anders Carlsson return LHS; 9143907323dd6665c0c4e383435cb145233f4533406Anders Carlsson 9153907323dd6665c0c4e383435cb145233f4533406Anders Carlsson return EvalVal(C->getRHS()); 91606de276fff91264437fa75111ed76de43097e089Ted Kremenek } 91706de276fff91264437fa75111ed76de43097e089Ted Kremenek 91806de276fff91264437fa75111ed76de43097e089Ted Kremenek // Accesses to members are potential references to data on the stack. 91906de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::MemberExprClass: { 92006de276fff91264437fa75111ed76de43097e089Ted Kremenek MemberExpr *M = cast<MemberExpr>(E); 92106de276fff91264437fa75111ed76de43097e089Ted Kremenek 92206de276fff91264437fa75111ed76de43097e089Ted Kremenek // Check for indirect access. We only want direct field accesses. 92306de276fff91264437fa75111ed76de43097e089Ted Kremenek if (!M->isArrow()) 92406de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalVal(M->getBase()); 92506de276fff91264437fa75111ed76de43097e089Ted Kremenek else 92606de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 92706de276fff91264437fa75111ed76de43097e089Ted Kremenek } 92806de276fff91264437fa75111ed76de43097e089Ted Kremenek 92906de276fff91264437fa75111ed76de43097e089Ted Kremenek // Everything else: we simply don't reason about them. 93006de276fff91264437fa75111ed76de43097e089Ted Kremenek default: 93106de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 93206de276fff91264437fa75111ed76de43097e089Ted Kremenek } 93306de276fff91264437fa75111ed76de43097e089Ted Kremenek} 934588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 935588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===// 936588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 937588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// Check for comparisons of floating point operands using != and ==. 938588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// Issue a warning if these are no self-comparisons, as they are not likely 939588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// to do what the programmer intended. 940588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenekvoid Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) { 941588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek bool EmitWarning = true; 942588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 9434e99a5fc3b203397a91136c6e695e405fb8fc606Ted Kremenek Expr* LeftExprSansParen = lex->IgnoreParens(); 94432e97b66bbce16c9e81c877794fb7a0aeeb66ccbTed Kremenek Expr* RightExprSansParen = rex->IgnoreParens(); 945588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 946588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Special case: check for x == x (which is OK). 947588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Do not emit warnings for such cases. 948588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen)) 949588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen)) 950588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DRL->getDecl() == DRR->getDecl()) 951588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 952588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 9531b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek 9541b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // Special case: check for comparisons against literals that can be exactly 9551b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // represented by APFloat. In such cases, do not emit a warning. This 9561b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // is a heuristic: often comparison against such literals are used to 9571b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // detect if a value in a variable has not changed. This clearly can 9581b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // lead to false negatives. 9591b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (EmitWarning) { 9601b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) { 9611b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FLL->isExact()) 9621b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek EmitWarning = false; 9631b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9641b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek else 9651b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){ 9661b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FLR->isExact()) 9671b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek EmitWarning = false; 9681b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9691b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9701b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek 971588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Check for comparisons with builtin types. 972588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 973588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen)) 974588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (isCallBuiltin(CL)) 975588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 976588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 977588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 978588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen)) 979588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (isCallBuiltin(CR)) 980588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 981588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 982588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Emit the diagnostic. 983588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 984588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek Diag(loc, diag::warn_floatingpoint_eq, 985588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek lex->getSourceRange(),rex->getSourceRange()); 986588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek} 987