SemaChecking.cpp revision 3c73c41cefcfe76f36b7bed72c9f1ec195490951
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(); 322def48394f6d48bde0dec2b514193c2b533265b5Douglas Gregor 332def48394f6d48bde0dec2b514193c2b533265b5Douglas Gregor // None of the checks below are needed for functions that don't have 342def48394f6d48bde0dec2b514193c2b533265b5Douglas Gregor // simple names (e.g., C++ conversion functions). 352def48394f6d48bde0dec2b514193c2b533265b5Douglas Gregor if (!FnInfo) 362def48394f6d48bde0dec2b514193c2b533265b5Douglas Gregor return TheCall.take(); 372def48394f6d48bde0dec2b514193c2b533265b5Douglas Gregor 3830ce344307f8a8b00054021307015571f83c7364Chris Lattner switch (FnInfo->getBuiltinID()) { 3930ce344307f8a8b00054021307015571f83c7364Chris Lattner case Builtin::BI__builtin___CFStringMakeConstantString: 40925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner assert(TheCall->getNumArgs() == 1 && 411b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner "Wrong # arguments to builtin CFStringMakeConstantString"); 42e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (CheckBuiltinCFStringArgument(TheCall->getArg(0))) 43d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 44e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 4549ff7a1c8c67d56e62d3b4627463b705c0d5008cTed Kremenek case Builtin::BI__builtin_stdarg_start: 4630ce344307f8a8b00054021307015571f83c7364Chris Lattner case Builtin::BI__builtin_va_start: 47b7cfe88e88cb4f46308de89cf3f0c81bfe624128Chris Lattner if (SemaBuiltinVAStart(TheCall.get())) 48d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 49e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 501b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isgreater: 511b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isgreaterequal: 521b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isless: 531b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_islessequal: 541b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_islessgreater: 551b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isunordered: 56e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (SemaBuiltinUnorderedCompare(TheCall.get())) 57d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 58e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 596cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman case Builtin::BI__builtin_return_address: 606cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman case Builtin::BI__builtin_frame_address: 616cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman if (SemaBuiltinStackAddress(TheCall.get())) 626cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return true; 636cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return TheCall.take(); 64d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman case Builtin::BI__builtin_shufflevector: 65e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return SemaBuiltinShuffleVector(TheCall.get()); 664493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar case Builtin::BI__builtin_prefetch: 674493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (SemaBuiltinPrefetch(TheCall.get())) 684493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar return true; 694493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar return TheCall.take(); 70d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar case Builtin::BI__builtin_object_size: 71d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar if (SemaBuiltinObjectSize(TheCall.get())) 72d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar return true; 7371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 74de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar 75de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar // FIXME: This mechanism should be abstracted to be less fragile and 76de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar // more efficient. For example, just map function ids to custom 77de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar // handlers. 78de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar 7959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // Search the KnownFunctionIDs for the identifier. 8059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner unsigned i = 0, e = id_num_known_functions; 8171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek for (; i != e; ++i) { if (KnownFunctionIDs[i] == FnInfo) break; } 82e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (i == e) return TheCall.take(); 8359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 8459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // Printf checking. 8559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner if (i <= id_vprintf) { 8671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Retrieve the index of the format string parameter and determine 8771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // if the function is passed a va_arg argument. 8859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner unsigned format_idx = 0; 8971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek bool HasVAListArg = false; 9071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 9159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner switch (i) { 9230ce344307f8a8b00054021307015571f83c7364Chris Lattner default: assert(false && "No format string argument index."); 93de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_NSLog: format_idx = 0; break; 94de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_asprintf: format_idx = 1; break; 95de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_fprintf: format_idx = 1; break; 96de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_printf: format_idx = 0; break; 97de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_snprintf: format_idx = 2; break; 98de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_snprintf_chk: format_idx = 4; break; 99de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_sprintf: format_idx = 1; break; 100de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_sprintf_chk: format_idx = 3; break; 101de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_vasprintf: format_idx = 1; HasVAListArg = true; break; 102de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_vfprintf: format_idx = 1; HasVAListArg = true; break; 103de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_vsnprintf: format_idx = 2; HasVAListArg = true; break; 104de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_vsnprintf_chk: format_idx = 4; HasVAListArg = true; break; 105de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_vsprintf: format_idx = 1; HasVAListArg = true; break; 106de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_vsprintf_chk: format_idx = 3; HasVAListArg = true; break; 107de45428f923b38d80407dbb9ede0df504256f9f6Daniel Dunbar case id_vprintf: format_idx = 0; HasVAListArg = true; break; 10871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 10971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 110e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman CheckPrintfArguments(TheCall.get(), HasVAListArg, format_idx); 11159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner } 11271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 113e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 11471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson} 11571993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 11671993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson/// CheckBuiltinCFStringArgument - Checks that the argument to the builtin 11771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson/// CFString constructor is correct 118cc6f65d9f210efc56d7418753e93bf5a14f3ac59Chris Lattnerbool Sema::CheckBuiltinCFStringArgument(Expr* Arg) { 11956f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner Arg = Arg->IgnoreParenCasts(); 12071993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 12171993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson StringLiteral *Literal = dyn_cast<StringLiteral>(Arg); 12271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 12371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson if (!Literal || Literal->isWide()) { 124fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner Diag(Arg->getLocStart(), diag::err_cfstring_literal_not_string_constant) 125fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << Arg->getSourceRange(); 1269cdc4d3834f203dcde3ff274b8928e4620a914d5Anders Carlsson return true; 12771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 12871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 12971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson const char *Data = Literal->getStrData(); 13071993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson unsigned Length = Literal->getByteLength(); 13171993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 13271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson for (unsigned i = 0; i < Length; ++i) { 13371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson if (!isascii(Data[i])) { 13471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Diag(PP.AdvanceToTokenCharacter(Arg->getLocStart(), i + 1), 135fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner diag::warn_cfstring_literal_contains_non_ascii_character) 136fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << Arg->getSourceRange(); 13771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson break; 13871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 13971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 14071993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson if (!Data[i]) { 14171993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Diag(PP.AdvanceToTokenCharacter(Arg->getLocStart(), i + 1), 142fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner diag::warn_cfstring_literal_contains_nul_character) 143fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << Arg->getSourceRange(); 14471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson break; 14571993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 14671993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 14771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 1489cdc4d3834f203dcde3ff274b8928e4620a914d5Anders Carlsson return false; 14959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner} 15059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 151c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity. 152c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner/// Emit an error and return true on failure, return false on success. 153925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattnerbool Sema::SemaBuiltinVAStart(CallExpr *TheCall) { 154925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *Fn = TheCall->getCallee(); 155925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (TheCall->getNumArgs() > 2) { 156925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(2)->getLocStart(), 157fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner diag::err_typecheck_call_too_many_args) 158fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << Fn->getSourceRange() 159fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << SourceRange(TheCall->getArg(2)->getLocStart(), 160fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner (*(TheCall->arg_end()-1))->getLocEnd()); 16130ce344307f8a8b00054021307015571f83c7364Chris Lattner return true; 16230ce344307f8a8b00054021307015571f83c7364Chris Lattner } 16330ce344307f8a8b00054021307015571f83c7364Chris Lattner 164c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner // Determine whether the current function is variadic or not. 165c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner bool isVariadic; 16653d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis if (getCurFunctionDecl()) 167c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner isVariadic = 16853d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis cast<FunctionTypeProto>(getCurFunctionDecl()->getType())->isVariadic(); 16930ce344307f8a8b00054021307015571f83c7364Chris Lattner else 17053d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis isVariadic = getCurMethodDecl()->isVariadic(); 17130ce344307f8a8b00054021307015571f83c7364Chris Lattner 172c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner if (!isVariadic) { 17330ce344307f8a8b00054021307015571f83c7364Chris Lattner Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function); 17430ce344307f8a8b00054021307015571f83c7364Chris Lattner return true; 17530ce344307f8a8b00054021307015571f83c7364Chris Lattner } 17630ce344307f8a8b00054021307015571f83c7364Chris Lattner 17730ce344307f8a8b00054021307015571f83c7364Chris Lattner // Verify that the second argument to the builtin is the last argument of the 17830ce344307f8a8b00054021307015571f83c7364Chris Lattner // current function or method. 17930ce344307f8a8b00054021307015571f83c7364Chris Lattner bool SecondArgIsLastNamedArgument = false; 180e2c14103dec39cbd24dac9d7b3e91277b109c14fAnders Carlsson const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts(); 18188cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson 18288cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) { 18388cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) { 18430ce344307f8a8b00054021307015571f83c7364Chris Lattner // FIXME: This isn't correct for methods (results in bogus warning). 18530ce344307f8a8b00054021307015571f83c7364Chris Lattner // Get the last formal in the current function. 18688cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson const ParmVarDecl *LastArg; 18753d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis if (getCurFunctionDecl()) 18853d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis LastArg = *(getCurFunctionDecl()->param_end()-1); 18930ce344307f8a8b00054021307015571f83c7364Chris Lattner else 19053d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis LastArg = *(getCurMethodDecl()->param_end()-1); 19130ce344307f8a8b00054021307015571f83c7364Chris Lattner SecondArgIsLastNamedArgument = PV == LastArg; 19230ce344307f8a8b00054021307015571f83c7364Chris Lattner } 19330ce344307f8a8b00054021307015571f83c7364Chris Lattner } 19430ce344307f8a8b00054021307015571f83c7364Chris Lattner 19530ce344307f8a8b00054021307015571f83c7364Chris Lattner if (!SecondArgIsLastNamedArgument) 196925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(1)->getLocStart(), 19730ce344307f8a8b00054021307015571f83c7364Chris Lattner diag::warn_second_parameter_of_va_start_not_last_named_argument); 19830ce344307f8a8b00054021307015571f83c7364Chris Lattner return false; 1996cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman} 20030ce344307f8a8b00054021307015571f83c7364Chris Lattner 2011b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and 2021b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner/// friends. This is declared to take (...), so we have to check everything. 203925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattnerbool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) { 204925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (TheCall->getNumArgs() < 2) 205925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args); 206925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (TheCall->getNumArgs() > 2) 207925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner return Diag(TheCall->getArg(2)->getLocStart(), 208fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner diag::err_typecheck_call_too_many_args) 209fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << SourceRange(TheCall->getArg(2)->getLocStart(), 210fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner (*(TheCall->arg_end()-1))->getLocEnd()); 2111b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 212925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *OrigArg0 = TheCall->getArg(0); 213925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *OrigArg1 = TheCall->getArg(1); 2141b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2151b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // Do standard promotions between the two arguments, returning their common 2161b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // type. 217925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false); 2181b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2191b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // If the common type isn't a real floating type, then the arguments were 2201b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // invalid for this operation. 2211b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner if (!Res->isRealFloatingType()) 222925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner return Diag(OrigArg0->getLocStart(), 223fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner diag::err_typecheck_call_invalid_ordered_compare) 224fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << OrigArg0->getType().getAsString() << OrigArg1->getType().getAsString() 225fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << SourceRange(OrigArg0->getLocStart(), OrigArg1->getLocEnd()); 2261b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2271b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner return false; 2281b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner} 2291b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2306cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedmanbool Sema::SemaBuiltinStackAddress(CallExpr *TheCall) { 2316cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman // The signature for these builtins is exact; the only thing we need 2326cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman // to check is that the argument is a constant. 2336cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman SourceLocation Loc; 234d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner if (!TheCall->getArg(0)->isIntegerConstantExpr(Context, &Loc)) 235fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(Loc, diag::err_stack_const_level) << TheCall->getSourceRange(); 236d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner 2376cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return false; 2386cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman} 2396cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman 240d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector. 241d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman// This is declared to take (...), so we have to check everything. 242d38617c8a50f9729c254ab76cd359af797c6739bEli FriedmanAction::ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) { 243d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (TheCall->getNumArgs() < 3) 244fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 245fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << TheCall->getSourceRange(); 246d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 247d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman QualType FAType = TheCall->getArg(0)->getType(); 248d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman QualType SAType = TheCall->getArg(1)->getType(); 249d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 250d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (!FAType->isVectorType() || !SAType->isVectorType()) { 251fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector) 252fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << SourceRange(TheCall->getArg(0)->getLocStart(), 253fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner TheCall->getArg(1)->getLocEnd()); 254d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 255d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 256d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 257b77792eabf5882cf9af8cc810599b20432fda6c2Chris Lattner if (Context.getCanonicalType(FAType).getUnqualifiedType() != 258b77792eabf5882cf9af8cc810599b20432fda6c2Chris Lattner Context.getCanonicalType(SAType).getUnqualifiedType()) { 259fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector) 260fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << SourceRange(TheCall->getArg(0)->getLocStart(), 261fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner TheCall->getArg(1)->getLocEnd()); 262d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 263d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 264d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 265d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman unsigned numElements = FAType->getAsVectorType()->getNumElements(); 266d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (TheCall->getNumArgs() != numElements+2) { 267d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (TheCall->getNumArgs() < numElements+2) 268fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args) 269fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << TheCall->getSourceRange(); 270fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_many_args) 271fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << TheCall->getSourceRange(); 272d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 273d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 274d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman for (unsigned i = 2; i < TheCall->getNumArgs(); i++) { 275d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman llvm::APSInt Result(32); 276d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context)) 277d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner return Diag(TheCall->getLocStart(), 278fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner diag::err_shufflevector_nonconstant_argument) 279fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << TheCall->getArg(i)->getSourceRange(); 280d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner 281d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2) 282d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner return Diag(TheCall->getLocStart(), 283fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner diag::err_shufflevector_argument_too_large) 284fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << TheCall->getArg(i)->getSourceRange(); 285d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 286d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 287d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman llvm::SmallVector<Expr*, 32> exprs; 288d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 289d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner for (unsigned i = 0, e = TheCall->getNumArgs(); i != e; i++) { 290d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman exprs.push_back(TheCall->getArg(i)); 291d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->setArg(i, 0); 292d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 293d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 294d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner return new ShuffleVectorExpr(exprs.begin(), numElements+2, FAType, 295d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner TheCall->getCallee()->getLocStart(), 296d1a0b6d3dfb208f638d3d750b588d9c0daa49289Chris Lattner TheCall->getRParenLoc()); 297d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman} 29830ce344307f8a8b00054021307015571f83c7364Chris Lattner 2994493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar/// SemaBuiltinPrefetch - Handle __builtin_prefetch. 3004493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar// This is declared to take (const void*, ...) and can take two 3014493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar// optional constant int args. 3024493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbarbool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) { 303fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner unsigned NumArgs = TheCall->getNumArgs(); 3044493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 305fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner if (NumArgs > 3) 306fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_many_args) 307fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << TheCall->getSourceRange(); 3084493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3094493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // Argument 0 is checked for us and the remaining arguments must be 3104493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // constant integers. 311fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner for (unsigned i = 1; i != NumArgs; ++i) { 3124493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar Expr *Arg = TheCall->getArg(i); 3134493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar QualType RWType = Arg->getType(); 3144493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3154493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar const BuiltinType *BT = RWType->getAsBuiltinType(); 316d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar llvm::APSInt Result; 3174493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (!BT || BT->getKind() != BuiltinType::Int || 318fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner !Arg->isIntegerConstantExpr(Result, Context)) 319fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(TheCall->getLocStart(), diag::err_prefetch_invalid_argument) 320fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 3214493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3224493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // FIXME: gcc issues a warning and rewrites these to 0. These 3234493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // seems especially odd for the third argument since the default 3244493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // is 3. 325fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner if (i == 1) { 3264493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (Result.getSExtValue() < 0 || Result.getSExtValue() > 1) 327fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 328fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << "0" << "1" << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 3294493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } else { 3304493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) 331fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 332fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 3334493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3344493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3354493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 336fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return false; 3374493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar} 3384493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 339d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar/// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr, 340d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar/// int type). This simply type checks that type is one of the defined 341d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar/// constants (0-3). 342d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbarbool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) { 343d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar Expr *Arg = TheCall->getArg(1); 344d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar QualType ArgType = Arg->getType(); 345d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar const BuiltinType *BT = ArgType->getAsBuiltinType(); 346d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar llvm::APSInt Result(32); 347d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar if (!BT || BT->getKind() != BuiltinType::Int || 348d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar !Arg->isIntegerConstantExpr(Result, Context)) { 349fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(TheCall->getLocStart(), diag::err_object_size_invalid_argument) 350fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 351d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar } 352d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar 353d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) { 354fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner return Diag(TheCall->getLocStart(), diag::err_argument_invalid_range) 355fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << "0" << "3" << SourceRange(Arg->getLocStart(), Arg->getLocEnd()); 356d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar } 357d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar 358d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar return false; 359d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar} 360d5f8a4fd4d6dfb0415b93bb7ab721bba5cab1332Daniel Dunbar 36159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// CheckPrintfArguments - Check calls to printf (and similar functions) for 36271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// correct use of format strings. 36371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 36471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// HasVAListArg - A predicate indicating whether the printf-like 36571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// function is passed an explicit va_arg argument (e.g., vprintf) 36671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 36771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// format_idx - The index into Args for the format string. 36871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 36971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Improper format strings to functions in the printf family can be 37071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// the source of bizarre bugs and very serious security holes. A 37171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// good source of information is available in the following paper 37271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (which includes additional references): 37359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// 37459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// FormatGuard: Automatic Protection From printf Format String 37559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// Vulnerabilities, Proceedings of the 10th USENIX Security Symposium, 2001. 37671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 37771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Functionality implemented: 37871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 37971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// We can statically check the following properties for string 38071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// literal format strings for non v.*printf functions (where the 38171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// arguments are passed directly): 38271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek// 38371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (1) Are the number of format conversions equal to the number of 38471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// data arguments? 38571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 38671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (2) Does each format conversion correctly match the type of the 38771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// corresponding data argument? (TODO) 38871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 38971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Moreover, for all printf functions we can: 39071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (3) Check for a missing format string (when not caught by type checking). 39271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (4) Check for no-operation flags; e.g. using "#" with format 39471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// conversion 'c' (TODO) 39571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (5) Check the use of '%n', a major source of security holes. 39771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (6) Check for malformed format conversions that don't specify anything. 39971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 40071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (7) Check for empty format strings. e.g: printf(""); 40171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 40271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (8) Check that the format string is a wide literal. 40371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 4046d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// (9) Also check the arguments of functions with the __format__ attribute. 4056d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// (TODO). 4066d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// 40771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// All of these checks can be done by parsing the format string. 40871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 40971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// For now, we ONLY do (1), (3), (5), (6), (7), and (8). 41059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattnervoid 411925e60d3fa706f31886027c876989af79eb0e0d2Chris LattnerSema::CheckPrintfArguments(CallExpr *TheCall, bool HasVAListArg, 412925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner unsigned format_idx) { 413925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *Fn = TheCall->getCallee(); 414925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner 41571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: printf-like function is called with no format string. 416925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (format_idx >= TheCall->getNumArgs()) { 417dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(TheCall->getRParenLoc(), diag::warn_printf_missing_format_string) 418dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << Fn->getSourceRange(); 41971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 42071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 42171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 42256f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts(); 423459e8488046be5df0bf57f0a8677316abf253167Chris Lattner 42459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // CHECK: format string is not a string literal. 42559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // 42671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Dynamically generated format strings are difficult to 42771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // automatically vet at compile time. Requiring that format strings 42871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // are string literals: (1) permits the checking of format strings by 42971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // the compiler and thereby (2) can practically remove the source of 43071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // many format string exploits. 4317ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 4327ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Format string can be either ObjC string (e.g. @"%d") or 4337ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // C string (e.g. "%d") 4347ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // ObjC string uses the same format specifiers as C string, so we can use 4357ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // the same format string checking logic for both ObjC and C strings. 4367ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(OrigFormatExpr); 4377ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek StringLiteral *FExpr = NULL; 4387ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 4397ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek if(ObjCFExpr != NULL) 4407ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek FExpr = ObjCFExpr->getString(); 4417ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek else 4427ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek FExpr = dyn_cast<StringLiteral>(OrigFormatExpr); 4437ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 44471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (FExpr == NULL) { 4454a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // For vprintf* functions (i.e., HasVAListArg==true), we add a 4464a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // special check to see if the format string is a function parameter 4474a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // of the function calling the printf function. If the function 4484a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // has an attribute indicating it is a printf-like function, then we 4494a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // should suppress warnings concerning non-literals being used in a call 4504a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // to a vprintf function. For example: 4514a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 4524a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // void 4534a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...) { 4544a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // va_list ap; 4554a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // va_start(ap, fmt); 4564a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // vprintf(fmt, ap); // Do NOT emit a warning about "fmt". 4574a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // ... 4584a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 4594a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 4604a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // FIXME: We don't have full attribute support yet, so just check to see 4614a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // if the argument is a DeclRefExpr that references a parameter. We'll 4624a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // add proper support for checking the attribute later. 4634a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek if (HasVAListArg) 464998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner if (DeclRefExpr* DR = dyn_cast<DeclRefExpr>(OrigFormatExpr)) 465998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner if (isa<ParmVarDecl>(DR->getDecl())) 4664a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek return; 4674a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek 468925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(format_idx)->getLocStart(), 469dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner diag::warn_printf_not_string_constant) 470dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << OrigFormatExpr->getSourceRange(); 47171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 47271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 47371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 47471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: is the format string a wide literal? 47571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (FExpr->isWide()) { 476925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(FExpr->getLocStart(), 477dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner diag::warn_printf_format_string_is_wide_literal) 478dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << OrigFormatExpr->getSourceRange(); 47971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 48071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 48171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 48271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Str - The format string. NOTE: this is NOT null-terminated! 48371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek const char * const Str = FExpr->getStrData(); 48471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 48571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: empty format string? 48671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek const unsigned StrLen = FExpr->getByteLength(); 48771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 48871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (StrLen == 0) { 489dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(FExpr->getLocStart(), diag::warn_printf_empty_format_string) 490dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << OrigFormatExpr->getSourceRange(); 49171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 49271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 49371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 49471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // We process the format string using a binary state machine. The 49571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // current state is stored in CurrentState. 49671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek enum { 49771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek state_OrdChr, 49871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek state_Conversion 49971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } CurrentState = state_OrdChr; 50071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 50171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // numConversions - The number of conversions seen so far. This is 50271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // incremented as we traverse the format string. 50371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned numConversions = 0; 50471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 50571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // numDataArgs - The number of data arguments after the format 50671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // string. This can only be determined for non vprintf-like 50771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // functions. For those functions, this value is 1 (the sole 50871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // va_arg argument). 509925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner unsigned numDataArgs = TheCall->getNumArgs()-(format_idx+1); 51071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 51171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Inspect the format string. 51271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned StrIdx = 0; 51371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 51471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // LastConversionIdx - Index within the format string where we last saw 51571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // a '%' character that starts a new format conversion. 51671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned LastConversionIdx = 0; 51771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 518925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner for (; StrIdx < StrLen; ++StrIdx) { 519998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner 52071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Is the number of detected conversion conversions greater than 52171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // the number of matching data arguments? If so, stop. 52271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (!HasVAListArg && numConversions > numDataArgs) break; 52371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 52471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Handle "\0" 525925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (Str[StrIdx] == '\0') { 52671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // The string returned by getStrData() is not null-terminated, 52771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // so the presence of a null character is likely an error. 528998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner Diag(PP.AdvanceToTokenCharacter(FExpr->getLocStart(), StrIdx+1), 529dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner diag::warn_printf_format_string_contains_null_char) 530dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << OrigFormatExpr->getSourceRange(); 53171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 53271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 53371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 53471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Ordinary characters (not processing a format conversion). 53571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (CurrentState == state_OrdChr) { 53671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (Str[StrIdx] == '%') { 53771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek CurrentState = state_Conversion; 53871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek LastConversionIdx = StrIdx; 53971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 54071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek continue; 54171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 54271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 54371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Seen '%'. Now processing a format conversion. 54471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek switch (Str[StrIdx]) { 545fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle dynamic precision or width specifier. 546fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case '*': { 547fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 548fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 549fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (!HasVAListArg && numConversions > numDataArgs) { 550fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = FExpr->getLocStart(); 551fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Loc = PP.AdvanceToTokenCharacter(Loc, StrIdx+1); 552580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek 553580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek if (Str[StrIdx-1] == '.') 554dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(Loc, diag::warn_printf_asterisk_precision_missing_arg) 555dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << OrigFormatExpr->getSourceRange(); 556580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek else 557dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(Loc, diag::warn_printf_asterisk_width_missing_arg) 558dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << OrigFormatExpr->getSourceRange(); 559580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek 560fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Don't do any more checking. We'll just emit spurious errors. 561fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return; 562580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek } 563fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 564fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Perform type checking on width/precision specifier. 565fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *E = TheCall->getArg(format_idx+numConversions); 566fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (const BuiltinType *BT = E->getType()->getAsBuiltinType()) 567fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (BT->getKind() == BuiltinType::Int) 568fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 569fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 570fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = 571fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner PP.AdvanceToTokenCharacter(FExpr->getLocStart(), StrIdx+1); 572fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 573fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (Str[StrIdx-1] == '.') 574dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(Loc, diag::warn_printf_asterisk_precision_wrong_type) 575dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << E->getType().getAsString() << E->getSourceRange(); 576fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 577dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(Loc, diag::warn_printf_asterisk_width_wrong_type) 578dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << E->getType().getAsString() << E->getSourceRange(); 579fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 580fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 581fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 582fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 583fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Characters which can terminate a format conversion 584fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // (e.g. "%d"). Characters that specify length modifiers or 585fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // other flags are handled by the default case below. 586fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // 587fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // FIXME: additional checks will go into the following cases. 588fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'i': 589fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'd': 590fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'o': 591fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'u': 592fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'x': 593fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'X': 594fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'D': 595fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'O': 596fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'U': 597fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'e': 598fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'E': 599fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'f': 600fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'F': 601fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'g': 602fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'G': 603fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'a': 604fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'A': 605fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'c': 606fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'C': 607fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'S': 608fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 's': 609fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'p': 610fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 611fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 612fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 61371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 614fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // CHECK: Are we using "%n"? Issue a warning. 615fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'n': { 616fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 617fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 618fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 619fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner LastConversionIdx+1); 620fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 621dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(Loc, diag::warn_printf_write_back)<<OrigFormatExpr->getSourceRange(); 622fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 623fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 6247ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 6257ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Handle "%@" 6267ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek case '@': 6277ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // %@ is allowed in ObjC format strings only. 6287ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek if(ObjCFExpr != NULL) 6297ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek CurrentState = state_OrdChr; 6307ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek else { 6317ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Issue a warning: invalid format conversion. 6327ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 6337ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek LastConversionIdx+1); 6347ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 6357ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek Diag(Loc, diag::warn_printf_invalid_conversion, 6367ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek std::string(Str+LastConversionIdx, 6377ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek Str+std::min(LastConversionIdx+2, StrLen)), 6389801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 6397ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek } 6407ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek ++numConversions; 6417ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek break; 6427ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 643fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle "%%" 644fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case '%': 645fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Sanity check: Was the first "%" character the previous one? 646fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // If not, we will assume that we have a malformed format 647fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // conversion, and that the current "%" character is the start 648fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // of a new conversion. 649fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (StrIdx - LastConversionIdx == 1) 650fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 651fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else { 652fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Issue a warning: invalid format conversion. 653925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 654925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx+1); 655fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 656fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_invalid_conversion, 657fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner std::string(Str+LastConversionIdx, Str+StrIdx), 6589801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 659fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 660fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // This conversion is broken. Advance to the next format 661fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // conversion. 662fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner LastConversionIdx = StrIdx; 663fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 66471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 665fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 66671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 667fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner default: 668fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // This case catches all other characters: flags, widths, etc. 669fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // We should eventually process those as well. 670fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 67171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 67271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 67371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 67471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (CurrentState == state_Conversion) { 67571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Issue a warning: invalid format conversion. 676925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 677925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx+1); 67871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 67971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Diag(Loc, diag::warn_printf_invalid_conversion, 680a9e2ea107d9419a6406f01e513679327032da193Chris Lattner std::string(Str+LastConversionIdx, 681a9e2ea107d9419a6406f01e513679327032da193Chris Lattner Str+std::min(LastConversionIdx+2, StrLen)), 6829801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 68371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 68471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 68571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 68671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (!HasVAListArg) { 68771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: Does the number of format conversions exceed the number 68871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // of data arguments? 68971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (numConversions > numDataArgs) { 690925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 691925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx); 69271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 693dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(Loc, diag::warn_printf_insufficient_data_args) 694dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << OrigFormatExpr->getSourceRange(); 69571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 69671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: Does the number of data arguments exceed the number of 69771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // format conversions in the format string? 69871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek else if (numConversions < numDataArgs) 699925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(format_idx+numConversions+1)->getLocStart(), 700dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner diag::warn_printf_too_many_data_args) 701dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << OrigFormatExpr->getSourceRange(); 70271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 70371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek} 70406de276fff91264437fa75111ed76de43097e089Ted Kremenek 70506de276fff91264437fa75111ed76de43097e089Ted Kremenek//===--- CHECK: Return Address of Stack Variable --------------------------===// 70606de276fff91264437fa75111ed76de43097e089Ted Kremenek 70706de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalVal(Expr *E); 70806de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalAddr(Expr* E); 70906de276fff91264437fa75111ed76de43097e089Ted Kremenek 71006de276fff91264437fa75111ed76de43097e089Ted Kremenek/// CheckReturnStackAddr - Check if a return statement returns the address 71106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// of a stack variable. 71206de276fff91264437fa75111ed76de43097e089Ted Kremenekvoid 71306de276fff91264437fa75111ed76de43097e089Ted KremenekSema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType, 71406de276fff91264437fa75111ed76de43097e089Ted Kremenek SourceLocation ReturnLoc) { 71556f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner 71606de276fff91264437fa75111ed76de43097e089Ted Kremenek // Perform checking for returned stack addresses. 717dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff if (lhsType->isPointerType() || lhsType->isBlockPointerType()) { 71806de276fff91264437fa75111ed76de43097e089Ted Kremenek if (DeclRefExpr *DR = EvalAddr(RetValExp)) 7193c73c41cefcfe76f36b7bed72c9f1ec195490951Chris Lattner Diag(DR->getLocStart(), diag::warn_ret_stack_addr) 7203c73c41cefcfe76f36b7bed72c9f1ec195490951Chris Lattner << DR->getDecl()->getIdentifier() << RetValExp->getSourceRange(); 721c50a4a5f2eac14ac4c631d50b0a55cadc87700ceSteve Naroff 722c50a4a5f2eac14ac4c631d50b0a55cadc87700ceSteve Naroff // Skip over implicit cast expressions when checking for block expressions. 723c50a4a5f2eac14ac4c631d50b0a55cadc87700ceSteve Naroff if (ImplicitCastExpr *IcExpr = 724c50a4a5f2eac14ac4c631d50b0a55cadc87700ceSteve Naroff dyn_cast_or_null<ImplicitCastExpr>(RetValExp)) 725c50a4a5f2eac14ac4c631d50b0a55cadc87700ceSteve Naroff RetValExp = IcExpr->getSubExpr(); 726c50a4a5f2eac14ac4c631d50b0a55cadc87700ceSteve Naroff 72761f40a2b67fc2046768e14f66b617e564cbcc3d8Steve Naroff if (BlockExpr *C = dyn_cast_or_null<BlockExpr>(RetValExp)) 728dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(C->getLocStart(), diag::err_ret_local_block) 729dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << C->getSourceRange(); 73006de276fff91264437fa75111ed76de43097e089Ted Kremenek } 73106de276fff91264437fa75111ed76de43097e089Ted Kremenek // Perform checking for stack values returned by reference. 73206de276fff91264437fa75111ed76de43097e089Ted Kremenek else if (lhsType->isReferenceType()) { 73349badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor // Check for a reference to the stack 73449badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor if (DeclRefExpr *DR = EvalVal(RetValExp)) 735dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner Diag(DR->getLocStart(), diag::warn_ret_stack_ref) 7363c73c41cefcfe76f36b7bed72c9f1ec195490951Chris Lattner << DR->getDecl()->getIdentifier() 737dcd5ef12488e4c7ea844327835896ca86b609a97Chris Lattner << RetValExp->getSourceRange(); 73806de276fff91264437fa75111ed76de43097e089Ted Kremenek } 73906de276fff91264437fa75111ed76de43097e089Ted Kremenek} 74006de276fff91264437fa75111ed76de43097e089Ted Kremenek 74106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that 74206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// check if the expression in a return statement evaluates to an address 74306de276fff91264437fa75111ed76de43097e089Ted Kremenek/// to a location on the stack. The recursion is used to traverse the 74406de276fff91264437fa75111ed76de43097e089Ted Kremenek/// AST of the return expression, with recursion backtracking when we 74506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// encounter a subexpression that (1) clearly does not lead to the address 74606de276fff91264437fa75111ed76de43097e089Ted Kremenek/// of a stack variable or (2) is something we cannot determine leads to 74706de276fff91264437fa75111ed76de43097e089Ted Kremenek/// the address of a stack variable based on such local checking. 74806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 749e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek/// EvalAddr processes expressions that are pointers that are used as 750e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek/// references (and not L-values). EvalVal handles all other values. 75106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// At the base case of the recursion is a check for a DeclRefExpr* in 75206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// the refers to a stack variable. 75306de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 75406de276fff91264437fa75111ed76de43097e089Ted Kremenek/// This implementation handles: 75506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 75606de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * pointer-to-pointer casts 75706de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * implicit conversions from array references to pointers 75806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * taking the address of fields 75906de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * arbitrary interplay between "&" and "*" operators 76006de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * pointer arithmetic from an address of a stack variable 76106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * taking the address of an array element where the array is on the stack 76206de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalAddr(Expr *E) { 76306de276fff91264437fa75111ed76de43097e089Ted Kremenek // We should only be called for evaluating pointer expressions. 764dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff assert((E->getType()->isPointerType() || 765dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff E->getType()->isBlockPointerType() || 766a526c5c67e5a0473c340903ee542ce570119665fTed Kremenek E->getType()->isObjCQualifiedIdType()) && 767fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner "EvalAddr only works on pointers"); 76806de276fff91264437fa75111ed76de43097e089Ted Kremenek 76906de276fff91264437fa75111ed76de43097e089Ted Kremenek // Our "symbolic interpreter" is just a dispatch off the currently 77006de276fff91264437fa75111ed76de43097e089Ted Kremenek // viewed AST node. We then recursively traverse the AST by calling 77106de276fff91264437fa75111ed76de43097e089Ted Kremenek // EvalAddr and EvalVal appropriately. 77206de276fff91264437fa75111ed76de43097e089Ted Kremenek switch (E->getStmtClass()) { 773fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ParenExprClass: 774fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Ignore parentheses. 775fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(cast<ParenExpr>(E)->getSubExpr()); 77606de276fff91264437fa75111ed76de43097e089Ted Kremenek 777fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::UnaryOperatorClass: { 778fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // The only unary operator that make sense to handle here 779fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // is AddrOf. All others don't make sense as pointers. 780fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner UnaryOperator *U = cast<UnaryOperator>(E); 78106de276fff91264437fa75111ed76de43097e089Ted Kremenek 782fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (U->getOpcode() == UnaryOperator::AddrOf) 783fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalVal(U->getSubExpr()); 784fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 785fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 786fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 787fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 788fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::BinaryOperatorClass: { 789fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle pointer arithmetic. All other binary operators are not valid 790fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // in this context. 791fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner BinaryOperator *B = cast<BinaryOperator>(E); 792fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner BinaryOperator::Opcode op = B->getOpcode(); 79306de276fff91264437fa75111ed76de43097e089Ted Kremenek 794fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (op != BinaryOperator::Add && op != BinaryOperator::Sub) 795fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 79606de276fff91264437fa75111ed76de43097e089Ted Kremenek 797fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *Base = B->getLHS(); 7983907323dd6665c0c4e383435cb145233f4533406Anders Carlsson 799fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Determine which argument is the real pointer base. It could be 800fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // the RHS argument instead of the LHS. 801fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (!Base->getType()->isPointerType()) Base = B->getRHS(); 80206de276fff91264437fa75111ed76de43097e089Ted Kremenek 803fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner assert (Base->getType()->isPointerType()); 804fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(Base); 805fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 80661f40a2b67fc2046768e14f66b617e564cbcc3d8Steve Naroff 807fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For conditional operators we need to see if either the LHS or RHS are 808fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // valid DeclRefExpr*s. If one of them is valid, we return it. 809fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ConditionalOperatorClass: { 810fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ConditionalOperator *C = cast<ConditionalOperator>(E); 811fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 812fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle the GNU extension for missing LHS. 813fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (Expr *lhsExpr = C->getLHS()) 814fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (DeclRefExpr* LHS = EvalAddr(lhsExpr)) 815fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return LHS; 81606de276fff91264437fa75111ed76de43097e089Ted Kremenek 817fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(C->getRHS()); 818fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 819fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 82054b5274f2c190331438375ad114dad12ae098b57Ted Kremenek // For casts, we need to handle conversions from arrays to 82154b5274f2c190331438375ad114dad12ae098b57Ted Kremenek // pointer values, and pointer-to-pointer conversions. 82249badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor case Stmt::ImplicitCastExprClass: 8236eec8e883de118b431e3ead5b1e604a6ac68ff6bDouglas Gregor case Stmt::CStyleCastExprClass: 82449badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor case Stmt::CXXFunctionalCastExprClass: { 8250835a3cdeefe714b4959d31127ea155e56393125Argyrios Kyrtzidis Expr* SubExpr = cast<CastExpr>(E)->getSubExpr(); 82654b5274f2c190331438375ad114dad12ae098b57Ted Kremenek QualType T = SubExpr->getType(); 827fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 828dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff if (SubExpr->getType()->isPointerType() || 829dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff SubExpr->getType()->isBlockPointerType() || 830dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff SubExpr->getType()->isObjCQualifiedIdType()) 831fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(SubExpr); 83254b5274f2c190331438375ad114dad12ae098b57Ted Kremenek else if (T->isArrayType()) 83354b5274f2c190331438375ad114dad12ae098b57Ted Kremenek return EvalVal(SubExpr); 834fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 83554b5274f2c190331438375ad114dad12ae098b57Ted Kremenek return 0; 836fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 837fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 838fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // C++ casts. For dynamic casts, static casts, and const casts, we 839fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // are always converting from a pointer-to-pointer, so we just blow 84049badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor // through the cast. In the case the dynamic cast doesn't fail (and 84149badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor // return NULL), we take the conservative route and report cases 842fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // where we return the address of a stack variable. For Reinterpre 84349badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor // FIXME: The comment about is wrong; we're not always converting 84449badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor // from pointer to pointer. I'm guessing that this code should also 84549badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor // handle references to objects. 84649badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor case Stmt::CXXStaticCastExprClass: 84749badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor case Stmt::CXXDynamicCastExprClass: 84849badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor case Stmt::CXXConstCastExprClass: 84949badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor case Stmt::CXXReinterpretCastExprClass: { 85049badde06e066d058d6c7fcf4e628a72999b65a9Douglas Gregor Expr *S = cast<CXXNamedCastExpr>(E)->getSubExpr(); 851dd972f20dc2bd3609d833893e5c6544ac09b59a9Steve Naroff if (S->getType()->isPointerType() || S->getType()->isBlockPointerType()) 852fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(S); 85306de276fff91264437fa75111ed76de43097e089Ted Kremenek else 85406de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 855fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 856fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 857fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Everything else: we simply don't reason about them. 858fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner default: 859fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 86006de276fff91264437fa75111ed76de43097e089Ted Kremenek } 86106de276fff91264437fa75111ed76de43097e089Ted Kremenek} 86206de276fff91264437fa75111ed76de43097e089Ted Kremenek 86306de276fff91264437fa75111ed76de43097e089Ted Kremenek 86406de276fff91264437fa75111ed76de43097e089Ted Kremenek/// EvalVal - This function is complements EvalAddr in the mutual recursion. 86506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// See the comments for EvalAddr for more details. 86606de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalVal(Expr *E) { 86706de276fff91264437fa75111ed76de43097e089Ted Kremenek 868e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // We should only be called for evaluating non-pointer expressions, or 869e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // expressions with a pointer type that are not used as references but instead 870e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // are l-values (e.g., DeclRefExpr with a pointer type). 871e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek 87206de276fff91264437fa75111ed76de43097e089Ted Kremenek // Our "symbolic interpreter" is just a dispatch off the currently 87306de276fff91264437fa75111ed76de43097e089Ted Kremenek // viewed AST node. We then recursively traverse the AST by calling 87406de276fff91264437fa75111ed76de43097e089Ted Kremenek // EvalAddr and EvalVal appropriately. 87506de276fff91264437fa75111ed76de43097e089Ted Kremenek switch (E->getStmtClass()) { 87606de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::DeclRefExprClass: { 87706de276fff91264437fa75111ed76de43097e089Ted Kremenek // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking 87806de276fff91264437fa75111ed76de43097e089Ted Kremenek // at code that refers to a variable's name. We check if it has local 87906de276fff91264437fa75111ed76de43097e089Ted Kremenek // storage within the function, and if so, return the expression. 88006de276fff91264437fa75111ed76de43097e089Ted Kremenek DeclRefExpr *DR = cast<DeclRefExpr>(E); 88106de276fff91264437fa75111ed76de43097e089Ted Kremenek 88206de276fff91264437fa75111ed76de43097e089Ted Kremenek if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) 88327c8dc06f65d7abcf6a7e7f64a7960c9a150ca01Douglas Gregor if(V->hasLocalStorage() && !V->getType()->isReferenceType()) return DR; 88406de276fff91264437fa75111ed76de43097e089Ted Kremenek 88506de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 88606de276fff91264437fa75111ed76de43097e089Ted Kremenek } 88706de276fff91264437fa75111ed76de43097e089Ted Kremenek 88806de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ParenExprClass: 88906de276fff91264437fa75111ed76de43097e089Ted Kremenek // Ignore parentheses. 89006de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalVal(cast<ParenExpr>(E)->getSubExpr()); 89106de276fff91264437fa75111ed76de43097e089Ted Kremenek 89206de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::UnaryOperatorClass: { 89306de276fff91264437fa75111ed76de43097e089Ted Kremenek // The only unary operator that make sense to handle here 89406de276fff91264437fa75111ed76de43097e089Ted Kremenek // is Deref. All others don't resolve to a "name." This includes 89506de276fff91264437fa75111ed76de43097e089Ted Kremenek // handling all sorts of rvalues passed to a unary operator. 89606de276fff91264437fa75111ed76de43097e089Ted Kremenek UnaryOperator *U = cast<UnaryOperator>(E); 89706de276fff91264437fa75111ed76de43097e089Ted Kremenek 89806de276fff91264437fa75111ed76de43097e089Ted Kremenek if (U->getOpcode() == UnaryOperator::Deref) 89906de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalAddr(U->getSubExpr()); 90006de276fff91264437fa75111ed76de43097e089Ted Kremenek 90106de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 90206de276fff91264437fa75111ed76de43097e089Ted Kremenek } 90306de276fff91264437fa75111ed76de43097e089Ted Kremenek 90406de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ArraySubscriptExprClass: { 90506de276fff91264437fa75111ed76de43097e089Ted Kremenek // Array subscripts are potential references to data on the stack. We 90606de276fff91264437fa75111ed76de43097e089Ted Kremenek // retrieve the DeclRefExpr* for the array variable if it indeed 90706de276fff91264437fa75111ed76de43097e089Ted Kremenek // has local storage. 9082324512285caac0332bbbc6e4cab6245d2a370a1Ted Kremenek return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase()); 90906de276fff91264437fa75111ed76de43097e089Ted Kremenek } 91006de276fff91264437fa75111ed76de43097e089Ted Kremenek 91106de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ConditionalOperatorClass: { 91206de276fff91264437fa75111ed76de43097e089Ted Kremenek // For conditional operators we need to see if either the LHS or RHS are 91306de276fff91264437fa75111ed76de43097e089Ted Kremenek // non-NULL DeclRefExpr's. If one is non-NULL, we return it. 91406de276fff91264437fa75111ed76de43097e089Ted Kremenek ConditionalOperator *C = cast<ConditionalOperator>(E); 91506de276fff91264437fa75111ed76de43097e089Ted Kremenek 9163907323dd6665c0c4e383435cb145233f4533406Anders Carlsson // Handle the GNU extension for missing LHS. 9173907323dd6665c0c4e383435cb145233f4533406Anders Carlsson if (Expr *lhsExpr = C->getLHS()) 9183907323dd6665c0c4e383435cb145233f4533406Anders Carlsson if (DeclRefExpr *LHS = EvalVal(lhsExpr)) 9193907323dd6665c0c4e383435cb145233f4533406Anders Carlsson return LHS; 9203907323dd6665c0c4e383435cb145233f4533406Anders Carlsson 9213907323dd6665c0c4e383435cb145233f4533406Anders Carlsson return EvalVal(C->getRHS()); 92206de276fff91264437fa75111ed76de43097e089Ted Kremenek } 92306de276fff91264437fa75111ed76de43097e089Ted Kremenek 92406de276fff91264437fa75111ed76de43097e089Ted Kremenek // Accesses to members are potential references to data on the stack. 92506de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::MemberExprClass: { 92606de276fff91264437fa75111ed76de43097e089Ted Kremenek MemberExpr *M = cast<MemberExpr>(E); 92706de276fff91264437fa75111ed76de43097e089Ted Kremenek 92806de276fff91264437fa75111ed76de43097e089Ted Kremenek // Check for indirect access. We only want direct field accesses. 92906de276fff91264437fa75111ed76de43097e089Ted Kremenek if (!M->isArrow()) 93006de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalVal(M->getBase()); 93106de276fff91264437fa75111ed76de43097e089Ted Kremenek else 93206de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 93306de276fff91264437fa75111ed76de43097e089Ted Kremenek } 93406de276fff91264437fa75111ed76de43097e089Ted Kremenek 93506de276fff91264437fa75111ed76de43097e089Ted Kremenek // Everything else: we simply don't reason about them. 93606de276fff91264437fa75111ed76de43097e089Ted Kremenek default: 93706de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 93806de276fff91264437fa75111ed76de43097e089Ted Kremenek } 93906de276fff91264437fa75111ed76de43097e089Ted Kremenek} 940588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 941588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===// 942588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 943588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// Check for comparisons of floating point operands using != and ==. 944588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// Issue a warning if these are no self-comparisons, as they are not likely 945588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// to do what the programmer intended. 946588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenekvoid Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) { 947588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek bool EmitWarning = true; 948588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 9494e99a5fc3b203397a91136c6e695e405fb8fc606Ted Kremenek Expr* LeftExprSansParen = lex->IgnoreParens(); 95032e97b66bbce16c9e81c877794fb7a0aeeb66ccbTed Kremenek Expr* RightExprSansParen = rex->IgnoreParens(); 951588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 952588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Special case: check for x == x (which is OK). 953588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Do not emit warnings for such cases. 954588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen)) 955588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen)) 956588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DRL->getDecl() == DRR->getDecl()) 957588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 958588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 9591b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek 9601b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // Special case: check for comparisons against literals that can be exactly 9611b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // represented by APFloat. In such cases, do not emit a warning. This 9621b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // is a heuristic: often comparison against such literals are used to 9631b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // detect if a value in a variable has not changed. This clearly can 9641b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // lead to false negatives. 9651b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (EmitWarning) { 9661b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) { 9671b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FLL->isExact()) 9681b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek EmitWarning = false; 9691b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9701b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek else 9711b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){ 9721b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FLR->isExact()) 9731b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek EmitWarning = false; 9741b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9751b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9761b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek 977588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Check for comparisons with builtin types. 978588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 979588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen)) 980588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (isCallBuiltin(CL)) 981588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 982588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 983588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 984588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen)) 985588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (isCallBuiltin(CR)) 986588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 987588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 988588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Emit the diagnostic. 989588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 990fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner Diag(loc, diag::warn_floatingpoint_eq) 991fa25bbb351f4fdd977f51254119cdfc2b525ce90Chris Lattner << lex->getSourceRange() << rex->getSourceRange(); 992588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek} 993