SemaChecking.cpp revision 9801c8b47a689c0633f7cb4df984aa8c1a52a658
159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner//===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===// 259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// The LLVM Compiler Infrastructure 459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 50bc735ffcfb223c0186419547abaa5c84482663eChris Lattner// This file is distributed under the University of Illinois Open Source 60bc735ffcfb223c0186419547abaa5c84482663eChris Lattner// License. See LICENSE.TXT for details. 759907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner//===----------------------------------------------------------------------===// 959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 1059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// This file implements extra semantic analysis beyond what is enforced 1159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// by the C type system. 1259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner// 1359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner//===----------------------------------------------------------------------===// 1459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 1559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "Sema.h" 1659907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/AST/ASTContext.h" 1759907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/AST/Decl.h" 1859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/AST/Expr.h" 192324512285caac0332bbbc6e4cab6245d2a370a1Ted Kremenek#include "clang/AST/ExprCXX.h" 207ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek#include "clang/AST/ExprObjC.h" 2159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Lex/Preprocessor.h" 2259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Lex/LiteralSupport.h" 2359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Basic/SourceManager.h" 2459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Basic/Diagnostic.h" 2559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Basic/LangOptions.h" 2659907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "clang/Basic/TargetInfo.h" 27e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman#include "llvm/ADT/OwningPtr.h" 2859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "llvm/ADT/SmallString.h" 2959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner#include "llvm/ADT/StringExtras.h" 30588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek#include "SemaUtil.h" 3159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattnerusing namespace clang; 3259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 3359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// CheckFunctionCall - Check a direct function call for various correctness 3459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// and safety properties not strictly enforced by the C type system. 35d38617c8a50f9729c254ab76cd359af797c6739bEli FriedmanAction::ExprResult 36e801870b638e47a5734a3ea63ddfb45f1711e078Eli FriedmanSema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCallRaw) { 37e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman llvm::OwningPtr<CallExpr> TheCall(TheCallRaw); 3859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // Get the IdentifierInfo* for the called function. 3959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner IdentifierInfo *FnInfo = FDecl->getIdentifier(); 4059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 4130ce344307f8a8b00054021307015571f83c7364Chris Lattner switch (FnInfo->getBuiltinID()) { 4230ce344307f8a8b00054021307015571f83c7364Chris Lattner case Builtin::BI__builtin___CFStringMakeConstantString: 43925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner assert(TheCall->getNumArgs() == 1 && 441b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner "Wrong # arguments to builtin CFStringMakeConstantString"); 45e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (CheckBuiltinCFStringArgument(TheCall->getArg(0))) 46d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 47e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 4849ff7a1c8c67d56e62d3b4627463b705c0d5008cTed Kremenek case Builtin::BI__builtin_stdarg_start: 4930ce344307f8a8b00054021307015571f83c7364Chris Lattner case Builtin::BI__builtin_va_start: 50b7cfe88e88cb4f46308de89cf3f0c81bfe624128Chris Lattner if (SemaBuiltinVAStart(TheCall.get())) 51d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 52e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 531b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isgreater: 541b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isgreaterequal: 551b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isless: 561b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_islessequal: 571b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_islessgreater: 581b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner case Builtin::BI__builtin_isunordered: 59e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (SemaBuiltinUnorderedCompare(TheCall.get())) 60d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 61e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 626cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman case Builtin::BI__builtin_return_address: 636cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman case Builtin::BI__builtin_frame_address: 646cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman if (SemaBuiltinStackAddress(TheCall.get())) 656cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return true; 666cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return TheCall.take(); 67d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman case Builtin::BI__builtin_shufflevector: 68e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return SemaBuiltinShuffleVector(TheCall.get()); 694493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar case Builtin::BI__builtin_prefetch: 704493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (SemaBuiltinPrefetch(TheCall.get())) 714493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar return true; 724493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar return TheCall.take(); 7371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 7471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 7559907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // Search the KnownFunctionIDs for the identifier. 7659907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner unsigned i = 0, e = id_num_known_functions; 7771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek for (; i != e; ++i) { if (KnownFunctionIDs[i] == FnInfo) break; } 78e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman if (i == e) return TheCall.take(); 7959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 8059907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // Printf checking. 8159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner if (i <= id_vprintf) { 8271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Retrieve the index of the format string parameter and determine 8371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // if the function is passed a va_arg argument. 8459907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner unsigned format_idx = 0; 8571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek bool HasVAListArg = false; 8671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 8759907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner switch (i) { 8830ce344307f8a8b00054021307015571f83c7364Chris Lattner default: assert(false && "No format string argument index."); 8930ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_printf: format_idx = 0; break; 9030ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_fprintf: format_idx = 1; break; 9130ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_sprintf: format_idx = 1; break; 9230ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_snprintf: format_idx = 2; break; 9330ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_asprintf: format_idx = 1; break; 947ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek case id_NSLog: format_idx = 0; break; 9530ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vsnprintf: format_idx = 2; HasVAListArg = true; break; 9630ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vasprintf: format_idx = 1; HasVAListArg = true; break; 9730ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vfprintf: format_idx = 1; HasVAListArg = true; break; 9830ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vsprintf: format_idx = 1; HasVAListArg = true; break; 9930ce344307f8a8b00054021307015571f83c7364Chris Lattner case id_vprintf: format_idx = 0; HasVAListArg = true; break; 10071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 10171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 102e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman CheckPrintfArguments(TheCall.get(), HasVAListArg, format_idx); 10359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner } 10471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 105e801870b638e47a5734a3ea63ddfb45f1711e078Eli Friedman return TheCall.take(); 10671993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson} 10771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 10871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson/// CheckBuiltinCFStringArgument - Checks that the argument to the builtin 10971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson/// CFString constructor is correct 110cc6f65d9f210efc56d7418753e93bf5a14f3ac59Chris Lattnerbool Sema::CheckBuiltinCFStringArgument(Expr* Arg) { 11156f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner Arg = Arg->IgnoreParenCasts(); 11271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 11371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson StringLiteral *Literal = dyn_cast<StringLiteral>(Arg); 11471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 11571993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson if (!Literal || Literal->isWide()) { 11671993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Diag(Arg->getLocStart(), 11771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson diag::err_cfstring_literal_not_string_constant, 11871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Arg->getSourceRange()); 1199cdc4d3834f203dcde3ff274b8928e4620a914d5Anders Carlsson return true; 12071993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 12171993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 12271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson const char *Data = Literal->getStrData(); 12371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson unsigned Length = Literal->getByteLength(); 12471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 12571993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson for (unsigned i = 0; i < Length; ++i) { 12671993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson if (!isascii(Data[i])) { 12771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Diag(PP.AdvanceToTokenCharacter(Arg->getLocStart(), i + 1), 12871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson diag::warn_cfstring_literal_contains_non_ascii_character, 12971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Arg->getSourceRange()); 13071993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson break; 13171993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 13271993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 13371993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson if (!Data[i]) { 13471993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Diag(PP.AdvanceToTokenCharacter(Arg->getLocStart(), i + 1), 13571993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson diag::warn_cfstring_literal_contains_nul_character, 13671993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson Arg->getSourceRange()); 13771993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson break; 13871993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 13971993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson } 14071993dd85eed9cc42c6b2fa61ee5c53026b74817Anders Carlsson 1419cdc4d3834f203dcde3ff274b8928e4620a914d5Anders Carlsson return false; 14259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner} 14359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner 144c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity. 145c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner/// Emit an error and return true on failure, return false on success. 146925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattnerbool Sema::SemaBuiltinVAStart(CallExpr *TheCall) { 147925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *Fn = TheCall->getCallee(); 148925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (TheCall->getNumArgs() > 2) { 149925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(2)->getLocStart(), 15030ce344307f8a8b00054021307015571f83c7364Chris Lattner diag::err_typecheck_call_too_many_args, Fn->getSourceRange(), 151925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceRange(TheCall->getArg(2)->getLocStart(), 152925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner (*(TheCall->arg_end()-1))->getLocEnd())); 15330ce344307f8a8b00054021307015571f83c7364Chris Lattner return true; 15430ce344307f8a8b00054021307015571f83c7364Chris Lattner } 15530ce344307f8a8b00054021307015571f83c7364Chris Lattner 156c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner // Determine whether the current function is variadic or not. 157c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner bool isVariadic; 15853d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis if (getCurFunctionDecl()) 159c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner isVariadic = 16053d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis cast<FunctionTypeProto>(getCurFunctionDecl()->getType())->isVariadic(); 16130ce344307f8a8b00054021307015571f83c7364Chris Lattner else 16253d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis isVariadic = getCurMethodDecl()->isVariadic(); 16330ce344307f8a8b00054021307015571f83c7364Chris Lattner 164c27c665c88b49dfb212aedc7bab8b9bf67658b9eChris Lattner if (!isVariadic) { 16530ce344307f8a8b00054021307015571f83c7364Chris Lattner Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function); 16630ce344307f8a8b00054021307015571f83c7364Chris Lattner return true; 16730ce344307f8a8b00054021307015571f83c7364Chris Lattner } 16830ce344307f8a8b00054021307015571f83c7364Chris Lattner 16930ce344307f8a8b00054021307015571f83c7364Chris Lattner // Verify that the second argument to the builtin is the last argument of the 17030ce344307f8a8b00054021307015571f83c7364Chris Lattner // current function or method. 17130ce344307f8a8b00054021307015571f83c7364Chris Lattner bool SecondArgIsLastNamedArgument = false; 172e2c14103dec39cbd24dac9d7b3e91277b109c14fAnders Carlsson const Expr *Arg = TheCall->getArg(1)->IgnoreParenCasts(); 17388cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson 17488cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Arg)) { 17588cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(DR->getDecl())) { 17630ce344307f8a8b00054021307015571f83c7364Chris Lattner // FIXME: This isn't correct for methods (results in bogus warning). 17730ce344307f8a8b00054021307015571f83c7364Chris Lattner // Get the last formal in the current function. 17888cf226caee50956ef47edd4d44cf7b80703a26cAnders Carlsson const ParmVarDecl *LastArg; 17953d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis if (getCurFunctionDecl()) 18053d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis LastArg = *(getCurFunctionDecl()->param_end()-1); 18130ce344307f8a8b00054021307015571f83c7364Chris Lattner else 18253d0ea5f5bfa647ec23418bf3a3b7c183b51e4bdArgyrios Kyrtzidis LastArg = *(getCurMethodDecl()->param_end()-1); 18330ce344307f8a8b00054021307015571f83c7364Chris Lattner SecondArgIsLastNamedArgument = PV == LastArg; 18430ce344307f8a8b00054021307015571f83c7364Chris Lattner } 18530ce344307f8a8b00054021307015571f83c7364Chris Lattner } 18630ce344307f8a8b00054021307015571f83c7364Chris Lattner 18730ce344307f8a8b00054021307015571f83c7364Chris Lattner if (!SecondArgIsLastNamedArgument) 188925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(1)->getLocStart(), 18930ce344307f8a8b00054021307015571f83c7364Chris Lattner diag::warn_second_parameter_of_va_start_not_last_named_argument); 19030ce344307f8a8b00054021307015571f83c7364Chris Lattner return false; 1916cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman} 19230ce344307f8a8b00054021307015571f83c7364Chris Lattner 1931b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner/// SemaBuiltinUnorderedCompare - Handle functions like __builtin_isgreater and 1941b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner/// friends. This is declared to take (...), so we have to check everything. 195925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattnerbool Sema::SemaBuiltinUnorderedCompare(CallExpr *TheCall) { 196925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (TheCall->getNumArgs() < 2) 197925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args); 198925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (TheCall->getNumArgs() > 2) 199925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner return Diag(TheCall->getArg(2)->getLocStart(), 200925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner diag::err_typecheck_call_too_many_args, 201925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceRange(TheCall->getArg(2)->getLocStart(), 202925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner (*(TheCall->arg_end()-1))->getLocEnd())); 2031b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 204925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *OrigArg0 = TheCall->getArg(0); 205925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *OrigArg1 = TheCall->getArg(1); 2061b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2071b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // Do standard promotions between the two arguments, returning their common 2081b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // type. 209925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner QualType Res = UsualArithmeticConversions(OrigArg0, OrigArg1, false); 2101b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2111b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // If the common type isn't a real floating type, then the arguments were 2121b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner // invalid for this operation. 2131b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner if (!Res->isRealFloatingType()) 214925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner return Diag(OrigArg0->getLocStart(), 2151b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner diag::err_typecheck_call_invalid_ordered_compare, 2161b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner OrigArg0->getType().getAsString(), 2171b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner OrigArg1->getType().getAsString(), 218925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceRange(OrigArg0->getLocStart(), OrigArg1->getLocEnd())); 2191b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2201b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner return false; 2211b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner} 2221b9a0793955070738cac6f04b5abe9496be9b317Chris Lattner 2236cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedmanbool Sema::SemaBuiltinStackAddress(CallExpr *TheCall) { 2246cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman // The signature for these builtins is exact; the only thing we need 2256cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman // to check is that the argument is a constant. 2266cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman SourceLocation Loc; 2276cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman if (!TheCall->getArg(0)->isIntegerConstantExpr(Context, &Loc)) { 2286cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return Diag(Loc, diag::err_stack_const_level, TheCall->getSourceRange()); 2296cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman } 2306cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman return false; 2316cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman} 2326cfda23b3768f93a6eb0b2a9135c8334a20125bbEli Friedman 233d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman/// SemaBuiltinShuffleVector - Handle __builtin_shufflevector. 234d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman// This is declared to take (...), so we have to check everything. 235d38617c8a50f9729c254ab76cd359af797c6739bEli FriedmanAction::ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) { 236d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (TheCall->getNumArgs() < 3) 237d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args, 238d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getSourceRange()); 239d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 240d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman QualType FAType = TheCall->getArg(0)->getType(); 241d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman QualType SAType = TheCall->getArg(1)->getType(); 242d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 243d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (!FAType->isVectorType() || !SAType->isVectorType()) { 244d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocStart(), diag::err_shufflevector_non_vector, 245d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman SourceRange(TheCall->getArg(0)->getLocStart(), 246d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getArg(1)->getLocEnd())); 247d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 248d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 249d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 250ba2561a0ab11afa64014828c759c491378ccc539Eli Friedman if (FAType.getCanonicalType().getUnqualifiedType() != 251ba2561a0ab11afa64014828c759c491378ccc539Eli Friedman SAType.getCanonicalType().getUnqualifiedType()) { 252d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocStart(), diag::err_shufflevector_incompatible_vector, 253d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman SourceRange(TheCall->getArg(0)->getLocStart(), 254d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getArg(1)->getLocEnd())); 255d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 256d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 257d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 258d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman unsigned numElements = FAType->getAsVectorType()->getNumElements(); 259d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (TheCall->getNumArgs() != numElements+2) { 260d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (TheCall->getNumArgs() < numElements+2) 261d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args, 262d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getSourceRange()); 263d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman else 264d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_many_args, 265d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getSourceRange()); 266d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 267d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 268d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 269d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman for (unsigned i = 2; i < TheCall->getNumArgs(); i++) { 270d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman llvm::APSInt Result(32); 271d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (!TheCall->getArg(i)->isIntegerConstantExpr(Result, Context)) { 272d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocStart(), 273d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman diag::err_shufflevector_nonconstant_argument, 274d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getArg(i)->getSourceRange()); 275d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 276d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 277d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman if (Result.getActiveBits() > 64 || Result.getZExtValue() >= numElements*2) { 278d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman Diag(TheCall->getLocStart(), 279d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman diag::err_shufflevector_argument_too_large, 280d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getArg(i)->getSourceRange()); 281d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return true; 282d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 283d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 284d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 285d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman llvm::SmallVector<Expr*, 32> exprs; 286d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 287d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman for (unsigned i = 0; i < TheCall->getNumArgs(); i++) { 288d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman exprs.push_back(TheCall->getArg(i)); 289d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->setArg(i, 0); 290d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman } 291d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 292d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman ShuffleVectorExpr* E = new ShuffleVectorExpr( 293d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman exprs.begin(), numElements+2, FAType, 294d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getCallee()->getLocStart(), 295d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman TheCall->getRParenLoc()); 296d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman 297d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman return E; 298d38617c8a50f9729c254ab76cd359af797c6739bEli Friedman} 29930ce344307f8a8b00054021307015571f83c7364Chris Lattner 3004493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar/// SemaBuiltinPrefetch - Handle __builtin_prefetch. 3014493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar// This is declared to take (const void*, ...) and can take two 3024493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar// optional constant int args. 3034493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbarbool Sema::SemaBuiltinPrefetch(CallExpr *TheCall) { 3044493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar unsigned numArgs = TheCall->getNumArgs(); 3054493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar bool res = false; 3064493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3074493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (numArgs > 3) { 3084493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar res |= Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_many_args, 3094493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar TheCall->getSourceRange()); 3104493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3114493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3124493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // Argument 0 is checked for us and the remaining arguments must be 3134493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // constant integers. 3144493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar for (unsigned i=1; i<numArgs; ++i) { 3154493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar Expr *Arg = TheCall->getArg(i); 3164493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar QualType RWType = Arg->getType(); 3174493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3184493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar const BuiltinType *BT = RWType->getAsBuiltinType(); 3194493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // FIXME: 32 is wrong, needs to be proper width of Int 3204493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar llvm::APSInt Result(32); 3214493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (!BT || BT->getKind() != BuiltinType::Int || 3224493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar !Arg->isIntegerConstantExpr(Result, Context)) { 3234493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (Diag(TheCall->getLocStart(), diag::err_prefetch_invalid_argument, 3244493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar SourceRange(Arg->getLocStart(), Arg->getLocEnd()))) { 3254493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar res = true; 3264493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar continue; 3274493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3284493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3294493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3304493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // FIXME: gcc issues a warning and rewrites these to 0. These 3314493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // seems especially odd for the third argument since the default 3324493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar // is 3. 3334493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (i==1) { 3344493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (Result.getSExtValue() < 0 || Result.getSExtValue() > 1) 3354493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar res |= Diag(TheCall->getLocStart(), diag::err_prefetch_invalid_range, 3364493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar "0", "1", 3374493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar SourceRange(Arg->getLocStart(), Arg->getLocEnd())); 3384493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } else { 3394493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar if (Result.getSExtValue() < 0 || Result.getSExtValue() > 3) 3404493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar res |= Diag(TheCall->getLocStart(), diag::err_prefetch_invalid_range, 3414493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar "0", "3", 3424493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar SourceRange(Arg->getLocStart(), Arg->getLocEnd())); 3434493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3444493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar } 3454493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 3464493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar return res; 3474493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar} 3484493f79fce48cd9cbd9f55fa9d452cde736747a0Daniel Dunbar 34959907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// CheckPrintfArguments - Check calls to printf (and similar functions) for 35071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// correct use of format strings. 35171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 35271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// HasVAListArg - A predicate indicating whether the printf-like 35371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// function is passed an explicit va_arg argument (e.g., vprintf) 35471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 35571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// format_idx - The index into Args for the format string. 35671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 35771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Improper format strings to functions in the printf family can be 35871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// the source of bizarre bugs and very serious security holes. A 35971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// good source of information is available in the following paper 36071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (which includes additional references): 36159907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// 36259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// FormatGuard: Automatic Protection From printf Format String 36359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner/// Vulnerabilities, Proceedings of the 10th USENIX Security Symposium, 2001. 36471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 36571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Functionality implemented: 36671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 36771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// We can statically check the following properties for string 36871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// literal format strings for non v.*printf functions (where the 36971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// arguments are passed directly): 37071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek// 37171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (1) Are the number of format conversions equal to the number of 37271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// data arguments? 37371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 37471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (2) Does each format conversion correctly match the type of the 37571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// corresponding data argument? (TODO) 37671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 37771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// Moreover, for all printf functions we can: 37871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 37971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (3) Check for a missing format string (when not caught by type checking). 38071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 38171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (4) Check for no-operation flags; e.g. using "#" with format 38271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// conversion 'c' (TODO) 38371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 38471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (5) Check the use of '%n', a major source of security holes. 38571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 38671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (6) Check for malformed format conversions that don't specify anything. 38771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 38871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (7) Check for empty format strings. e.g: printf(""); 38971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// (8) Check that the format string is a wide literal. 39171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 3926d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// (9) Also check the arguments of functions with the __format__ attribute. 3936d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// (TODO). 3946d43959ad845a43f27e00d2720f6bc3d3219d632Ted Kremenek/// 39571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// All of these checks can be done by parsing the format string. 39671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// 39771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek/// For now, we ONLY do (1), (3), (5), (6), (7), and (8). 39859907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattnervoid 399925e60d3fa706f31886027c876989af79eb0e0d2Chris LattnerSema::CheckPrintfArguments(CallExpr *TheCall, bool HasVAListArg, 400925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner unsigned format_idx) { 401925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Expr *Fn = TheCall->getCallee(); 402925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner 40371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: printf-like function is called with no format string. 404925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (format_idx >= TheCall->getNumArgs()) { 405925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getRParenLoc(), diag::warn_printf_missing_format_string, 40671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Fn->getSourceRange()); 40771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 40871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 40971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 41056f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner Expr *OrigFormatExpr = TheCall->getArg(format_idx)->IgnoreParenCasts(); 411459e8488046be5df0bf57f0a8677316abf253167Chris Lattner 41259907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // CHECK: format string is not a string literal. 41359907c4d8f6fc8aacfdaa0273bd7a9c140fbb45fChris Lattner // 41471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Dynamically generated format strings are difficult to 41571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // automatically vet at compile time. Requiring that format strings 41671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // are string literals: (1) permits the checking of format strings by 41771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // the compiler and thereby (2) can practically remove the source of 41871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // many format string exploits. 4197ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 4207ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Format string can be either ObjC string (e.g. @"%d") or 4217ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // C string (e.g. "%d") 4227ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // ObjC string uses the same format specifiers as C string, so we can use 4237ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // the same format string checking logic for both ObjC and C strings. 4247ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek ObjCStringLiteral *ObjCFExpr = dyn_cast<ObjCStringLiteral>(OrigFormatExpr); 4257ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek StringLiteral *FExpr = NULL; 4267ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 4277ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek if(ObjCFExpr != NULL) 4287ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek FExpr = ObjCFExpr->getString(); 4297ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek else 4307ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek FExpr = dyn_cast<StringLiteral>(OrigFormatExpr); 4317ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 43271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (FExpr == NULL) { 4334a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // For vprintf* functions (i.e., HasVAListArg==true), we add a 4344a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // special check to see if the format string is a function parameter 4354a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // of the function calling the printf function. If the function 4364a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // has an attribute indicating it is a printf-like function, then we 4374a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // should suppress warnings concerning non-literals being used in a call 4384a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // to a vprintf function. For example: 4394a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 4404a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // void 4414a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // logmessage(char const *fmt __attribute__ (format (printf, 1, 2)), ...) { 4424a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // va_list ap; 4434a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // va_start(ap, fmt); 4444a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // vprintf(fmt, ap); // Do NOT emit a warning about "fmt". 4454a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // ... 4464a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 4474a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // 4484a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // FIXME: We don't have full attribute support yet, so just check to see 4494a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // if the argument is a DeclRefExpr that references a parameter. We'll 4504a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek // add proper support for checking the attribute later. 4514a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek if (HasVAListArg) 452998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner if (DeclRefExpr* DR = dyn_cast<DeclRefExpr>(OrigFormatExpr)) 453998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner if (isa<ParmVarDecl>(DR->getDecl())) 4544a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek return; 4554a33646560c4faf8fb82a681360eb2dc0573d558Ted Kremenek 456925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(format_idx)->getLocStart(), 4579801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek diag::warn_printf_not_string_constant, 4589801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 45971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 46071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 46171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 46271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: is the format string a wide literal? 46371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (FExpr->isWide()) { 464925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(FExpr->getLocStart(), 4659801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek diag::warn_printf_format_string_is_wide_literal, 4669801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 46771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 46871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 46971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 47071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Str - The format string. NOTE: this is NOT null-terminated! 47171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek const char * const Str = FExpr->getStrData(); 47271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 47371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: empty format string? 47471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek const unsigned StrLen = FExpr->getByteLength(); 47571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 47671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (StrLen == 0) { 477925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(FExpr->getLocStart(), diag::warn_printf_empty_format_string, 4789801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 47971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 48071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 48171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 48271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // We process the format string using a binary state machine. The 48371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // current state is stored in CurrentState. 48471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek enum { 48571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek state_OrdChr, 48671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek state_Conversion 48771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } CurrentState = state_OrdChr; 48871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 48971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // numConversions - The number of conversions seen so far. This is 49071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // incremented as we traverse the format string. 49171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned numConversions = 0; 49271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 49371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // numDataArgs - The number of data arguments after the format 49471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // string. This can only be determined for non vprintf-like 49571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // functions. For those functions, this value is 1 (the sole 49671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // va_arg argument). 497925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner unsigned numDataArgs = TheCall->getNumArgs()-(format_idx+1); 49871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 49971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Inspect the format string. 50071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned StrIdx = 0; 50171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 50271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // LastConversionIdx - Index within the format string where we last saw 50371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // a '%' character that starts a new format conversion. 50471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek unsigned LastConversionIdx = 0; 50571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 506925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner for (; StrIdx < StrLen; ++StrIdx) { 507998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner 50871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Is the number of detected conversion conversions greater than 50971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // the number of matching data arguments? If so, stop. 51071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (!HasVAListArg && numConversions > numDataArgs) break; 51171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 51271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Handle "\0" 513925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner if (Str[StrIdx] == '\0') { 51471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // The string returned by getStrData() is not null-terminated, 51571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // so the presence of a null character is likely an error. 516998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner Diag(PP.AdvanceToTokenCharacter(FExpr->getLocStart(), StrIdx+1), 517998568f24d6665b8a9bf26b42a04e5f80d14668fChris Lattner diag::warn_printf_format_string_contains_null_char, 5189801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 51971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 52071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 52171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 52271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Ordinary characters (not processing a format conversion). 52371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (CurrentState == state_OrdChr) { 52471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (Str[StrIdx] == '%') { 52571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek CurrentState = state_Conversion; 52671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek LastConversionIdx = StrIdx; 52771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 52871895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek continue; 52971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 53071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 53171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Seen '%'. Now processing a format conversion. 53271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek switch (Str[StrIdx]) { 533fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle dynamic precision or width specifier. 534fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case '*': { 535fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 536fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 537fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (!HasVAListArg && numConversions > numDataArgs) { 538fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = FExpr->getLocStart(); 539fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Loc = PP.AdvanceToTokenCharacter(Loc, StrIdx+1); 540580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek 541580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek if (Str[StrIdx-1] == '.') 542fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_precision_missing_arg, 5439801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 544580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek else 545fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_width_missing_arg, 5469801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 547580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek 548fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Don't do any more checking. We'll just emit spurious errors. 549fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return; 550580b664e9c2acd3bffddfea79b1ce2863cfd9dd0Ted Kremenek } 551fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 552fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Perform type checking on width/precision specifier. 553fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *E = TheCall->getArg(format_idx+numConversions); 554fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (const BuiltinType *BT = E->getType()->getAsBuiltinType()) 555fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (BT->getKind() == BuiltinType::Int) 556fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 557fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 558fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = 559fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner PP.AdvanceToTokenCharacter(FExpr->getLocStart(), StrIdx+1); 560fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 561fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (Str[StrIdx-1] == '.') 562fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_precision_wrong_type, 563fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner E->getType().getAsString(), E->getSourceRange()); 564fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 565fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_asterisk_width_wrong_type, 566fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner E->getType().getAsString(), E->getSourceRange()); 567fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 568fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 569fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 570fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 571fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Characters which can terminate a format conversion 572fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // (e.g. "%d"). Characters that specify length modifiers or 573fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // other flags are handled by the default case below. 574fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // 575fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // FIXME: additional checks will go into the following cases. 576fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'i': 577fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'd': 578fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'o': 579fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'u': 580fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'x': 581fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'X': 582fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'D': 583fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'O': 584fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'U': 585fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'e': 586fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'E': 587fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'f': 588fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'F': 589fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'g': 590fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'G': 591fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'a': 592fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'A': 593fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'c': 594fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'C': 595fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'S': 596fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 's': 597fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'p': 598fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 599fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 600fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 60171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 602fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // CHECK: Are we using "%n"? Issue a warning. 603fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case 'n': { 604fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 605fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 606fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 607fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner LastConversionIdx+1); 608fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 6099801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek Diag(Loc, diag::warn_printf_write_back, OrigFormatExpr->getSourceRange()); 610fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 611fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 6127ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 6137ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Handle "%@" 6147ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek case '@': 6157ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // %@ is allowed in ObjC format strings only. 6167ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek if(ObjCFExpr != NULL) 6177ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek CurrentState = state_OrdChr; 6187ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek else { 6197ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek // Issue a warning: invalid format conversion. 6207ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 6217ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek LastConversionIdx+1); 6227ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 6237ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek Diag(Loc, diag::warn_printf_invalid_conversion, 6247ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek std::string(Str+LastConversionIdx, 6257ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek Str+std::min(LastConversionIdx+2, StrLen)), 6269801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 6277ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek } 6287ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek ++numConversions; 6297ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek break; 6307ff22b259d4d4729f701679e3a7f0e242365e07fTed Kremenek 631fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle "%%" 632fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case '%': 633fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Sanity check: Was the first "%" character the previous one? 634fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // If not, we will assume that we have a malformed format 635fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // conversion, and that the current "%" character is the start 636fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // of a new conversion. 637fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (StrIdx - LastConversionIdx == 1) 638fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CurrentState = state_OrdChr; 639fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else { 640fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Issue a warning: invalid format conversion. 641925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 642925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx+1); 643fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 644fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Diag(Loc, diag::warn_printf_invalid_conversion, 645fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner std::string(Str+LastConversionIdx, Str+StrIdx), 6469801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 647fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 648fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // This conversion is broken. Advance to the next format 649fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // conversion. 650fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner LastConversionIdx = StrIdx; 651fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ++numConversions; 65271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 653fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 65471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 655fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner default: 656fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // This case catches all other characters: flags, widths, etc. 657fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // We should eventually process those as well. 658fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner break; 65971895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 66071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 66171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 66271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (CurrentState == state_Conversion) { 66371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // Issue a warning: invalid format conversion. 664925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 665925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx+1); 66671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 66771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Diag(Loc, diag::warn_printf_invalid_conversion, 668a9e2ea107d9419a6406f01e513679327032da193Chris Lattner std::string(Str+LastConversionIdx, 669a9e2ea107d9419a6406f01e513679327032da193Chris Lattner Str+std::min(LastConversionIdx+2, StrLen)), 6709801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 67171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek return; 67271895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 67371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 67471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (!HasVAListArg) { 67571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: Does the number of format conversions exceed the number 67671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // of data arguments? 67771895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek if (numConversions > numDataArgs) { 678925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner SourceLocation Loc = PP.AdvanceToTokenCharacter(FExpr->getLocStart(), 679925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner LastConversionIdx); 68071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek 68171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek Diag(Loc, diag::warn_printf_insufficient_data_args, 6829801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 68371895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 68471895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // CHECK: Does the number of data arguments exceed the number of 68571895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek // format conversions in the format string? 68671895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek else if (numConversions < numDataArgs) 687925e60d3fa706f31886027c876989af79eb0e0d2Chris Lattner Diag(TheCall->getArg(format_idx+numConversions+1)->getLocStart(), 6889801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek diag::warn_printf_too_many_data_args, 6899801c8b47a689c0633f7cb4df984aa8c1a52a658Ted Kremenek OrigFormatExpr->getSourceRange()); 69071895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek } 69171895b9aa3ad71957359497e136b50fcb6136bdfTed Kremenek} 69206de276fff91264437fa75111ed76de43097e089Ted Kremenek 69306de276fff91264437fa75111ed76de43097e089Ted Kremenek//===--- CHECK: Return Address of Stack Variable --------------------------===// 69406de276fff91264437fa75111ed76de43097e089Ted Kremenek 69506de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalVal(Expr *E); 69606de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalAddr(Expr* E); 69706de276fff91264437fa75111ed76de43097e089Ted Kremenek 69806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// CheckReturnStackAddr - Check if a return statement returns the address 69906de276fff91264437fa75111ed76de43097e089Ted Kremenek/// of a stack variable. 70006de276fff91264437fa75111ed76de43097e089Ted Kremenekvoid 70106de276fff91264437fa75111ed76de43097e089Ted KremenekSema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType, 70206de276fff91264437fa75111ed76de43097e089Ted Kremenek SourceLocation ReturnLoc) { 70356f349400c5932a196509c0480ff6f99a9a0b48fChris Lattner 70406de276fff91264437fa75111ed76de43097e089Ted Kremenek // Perform checking for returned stack addresses. 70506de276fff91264437fa75111ed76de43097e089Ted Kremenek if (lhsType->isPointerType()) { 70606de276fff91264437fa75111ed76de43097e089Ted Kremenek if (DeclRefExpr *DR = EvalAddr(RetValExp)) 70706de276fff91264437fa75111ed76de43097e089Ted Kremenek Diag(DR->getLocStart(), diag::warn_ret_stack_addr, 70806de276fff91264437fa75111ed76de43097e089Ted Kremenek DR->getDecl()->getIdentifier()->getName(), 70906de276fff91264437fa75111ed76de43097e089Ted Kremenek RetValExp->getSourceRange()); 71006de276fff91264437fa75111ed76de43097e089Ted Kremenek } 71106de276fff91264437fa75111ed76de43097e089Ted Kremenek // Perform checking for stack values returned by reference. 71206de276fff91264437fa75111ed76de43097e089Ted Kremenek else if (lhsType->isReferenceType()) { 71396eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek // Check for an implicit cast to a reference. 71496eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek if (ImplicitCastExpr *I = dyn_cast<ImplicitCastExpr>(RetValExp)) 71596eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek if (DeclRefExpr *DR = EvalVal(I->getSubExpr())) 71696eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek Diag(DR->getLocStart(), diag::warn_ret_stack_ref, 71796eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek DR->getDecl()->getIdentifier()->getName(), 71896eabe0838ccd1d5a5d24a648b932763cdf3fa31Ted Kremenek RetValExp->getSourceRange()); 71906de276fff91264437fa75111ed76de43097e089Ted Kremenek } 72006de276fff91264437fa75111ed76de43097e089Ted Kremenek} 72106de276fff91264437fa75111ed76de43097e089Ted Kremenek 72206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// EvalAddr - EvalAddr and EvalVal are mutually recursive functions that 72306de276fff91264437fa75111ed76de43097e089Ted Kremenek/// check if the expression in a return statement evaluates to an address 72406de276fff91264437fa75111ed76de43097e089Ted Kremenek/// to a location on the stack. The recursion is used to traverse the 72506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// AST of the return expression, with recursion backtracking when we 72606de276fff91264437fa75111ed76de43097e089Ted Kremenek/// encounter a subexpression that (1) clearly does not lead to the address 72706de276fff91264437fa75111ed76de43097e089Ted Kremenek/// of a stack variable or (2) is something we cannot determine leads to 72806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// the address of a stack variable based on such local checking. 72906de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 730e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek/// EvalAddr processes expressions that are pointers that are used as 731e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek/// references (and not L-values). EvalVal handles all other values. 73206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// At the base case of the recursion is a check for a DeclRefExpr* in 73306de276fff91264437fa75111ed76de43097e089Ted Kremenek/// the refers to a stack variable. 73406de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 73506de276fff91264437fa75111ed76de43097e089Ted Kremenek/// This implementation handles: 73606de276fff91264437fa75111ed76de43097e089Ted Kremenek/// 73706de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * pointer-to-pointer casts 73806de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * implicit conversions from array references to pointers 73906de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * taking the address of fields 74006de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * arbitrary interplay between "&" and "*" operators 74106de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * pointer arithmetic from an address of a stack variable 74206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// * taking the address of an array element where the array is on the stack 74306de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalAddr(Expr *E) { 74406de276fff91264437fa75111ed76de43097e089Ted Kremenek // We should only be called for evaluating pointer expressions. 745fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner assert((E->getType()->isPointerType() || 746a526c5c67e5a0473c340903ee542ce570119665fTed Kremenek E->getType()->isObjCQualifiedIdType()) && 747fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner "EvalAddr only works on pointers"); 74806de276fff91264437fa75111ed76de43097e089Ted Kremenek 74906de276fff91264437fa75111ed76de43097e089Ted Kremenek // Our "symbolic interpreter" is just a dispatch off the currently 75006de276fff91264437fa75111ed76de43097e089Ted Kremenek // viewed AST node. We then recursively traverse the AST by calling 75106de276fff91264437fa75111ed76de43097e089Ted Kremenek // EvalAddr and EvalVal appropriately. 75206de276fff91264437fa75111ed76de43097e089Ted Kremenek switch (E->getStmtClass()) { 753fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ParenExprClass: 754fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Ignore parentheses. 755fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(cast<ParenExpr>(E)->getSubExpr()); 75606de276fff91264437fa75111ed76de43097e089Ted Kremenek 757fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::UnaryOperatorClass: { 758fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // The only unary operator that make sense to handle here 759fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // is AddrOf. All others don't make sense as pointers. 760fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner UnaryOperator *U = cast<UnaryOperator>(E); 76106de276fff91264437fa75111ed76de43097e089Ted Kremenek 762fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (U->getOpcode() == UnaryOperator::AddrOf) 763fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalVal(U->getSubExpr()); 764fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 765fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 766fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 767fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 768fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::BinaryOperatorClass: { 769fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle pointer arithmetic. All other binary operators are not valid 770fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // in this context. 771fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner BinaryOperator *B = cast<BinaryOperator>(E); 772fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner BinaryOperator::Opcode op = B->getOpcode(); 77306de276fff91264437fa75111ed76de43097e089Ted Kremenek 774fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (op != BinaryOperator::Add && op != BinaryOperator::Sub) 775fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 77606de276fff91264437fa75111ed76de43097e089Ted Kremenek 777fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *Base = B->getLHS(); 7783907323dd6665c0c4e383435cb145233f4533406Anders Carlsson 779fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Determine which argument is the real pointer base. It could be 780fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // the RHS argument instead of the LHS. 781fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (!Base->getType()->isPointerType()) Base = B->getRHS(); 78206de276fff91264437fa75111ed76de43097e089Ted Kremenek 783fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner assert (Base->getType()->isPointerType()); 784fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(Base); 785fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 786fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 787fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For conditional operators we need to see if either the LHS or RHS are 788fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // valid DeclRefExpr*s. If one of them is valid, we return it. 789fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ConditionalOperatorClass: { 790fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ConditionalOperator *C = cast<ConditionalOperator>(E); 791fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 792fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Handle the GNU extension for missing LHS. 793fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (Expr *lhsExpr = C->getLHS()) 794fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (DeclRefExpr* LHS = EvalAddr(lhsExpr)) 795fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return LHS; 79606de276fff91264437fa75111ed76de43097e089Ted Kremenek 797fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(C->getRHS()); 798fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 799fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 800fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For implicit casts, we need to handle conversions from arrays to 801fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // pointer values, and implicit pointer-to-pointer conversions. 802fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::ImplicitCastExprClass: { 803fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E); 804fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr* SubExpr = IE->getSubExpr(); 805fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 806fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (SubExpr->getType()->isPointerType() || 807a526c5c67e5a0473c340903ee542ce570119665fTed Kremenek SubExpr->getType()->isObjCQualifiedIdType()) 808fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(SubExpr); 809fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 810fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalVal(SubExpr); 811fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 812fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 813fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For casts, we handle pointer-to-pointer conversions (which 814fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // is essentially a no-op from our mini-interpreter's standpoint). 815fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // For other casts we abort. 816fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::CastExprClass: { 817fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CastExpr *C = cast<CastExpr>(E); 818fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *SubExpr = C->getSubExpr(); 819fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 820fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (SubExpr->getType()->isPointerType()) 821fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(SubExpr); 822fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 823fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 824fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 825fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 826fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // C++ casts. For dynamic casts, static casts, and const casts, we 827fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // are always converting from a pointer-to-pointer, so we just blow 828fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // through the cast. In the case the dynamic cast doesn't fail 829fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // (and return NULL), we take the conservative route and report cases 830fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // where we return the address of a stack variable. For Reinterpre 831fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner case Stmt::CXXCastExprClass: { 832fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner CXXCastExpr *C = cast<CXXCastExpr>(E); 833fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 834fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (C->getOpcode() == CXXCastExpr::ReinterpretCast) { 835fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner Expr *S = C->getSubExpr(); 836fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner if (S->getType()->isPointerType()) 837fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(S); 83806de276fff91264437fa75111ed76de43097e089Ted Kremenek else 83906de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 84006de276fff91264437fa75111ed76de43097e089Ted Kremenek } 841fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner else 842fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return EvalAddr(C->getSubExpr()); 843fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner } 844fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner 845fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner // Everything else: we simply don't reason about them. 846fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner default: 847fae3f1f6565c74d3238747b58357a6e56fbb0e9cChris Lattner return NULL; 84806de276fff91264437fa75111ed76de43097e089Ted Kremenek } 84906de276fff91264437fa75111ed76de43097e089Ted Kremenek} 85006de276fff91264437fa75111ed76de43097e089Ted Kremenek 85106de276fff91264437fa75111ed76de43097e089Ted Kremenek 85206de276fff91264437fa75111ed76de43097e089Ted Kremenek/// EvalVal - This function is complements EvalAddr in the mutual recursion. 85306de276fff91264437fa75111ed76de43097e089Ted Kremenek/// See the comments for EvalAddr for more details. 85406de276fff91264437fa75111ed76de43097e089Ted Kremenekstatic DeclRefExpr* EvalVal(Expr *E) { 85506de276fff91264437fa75111ed76de43097e089Ted Kremenek 856e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // We should only be called for evaluating non-pointer expressions, or 857e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // expressions with a pointer type that are not used as references but instead 858e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek // are l-values (e.g., DeclRefExpr with a pointer type). 859e8c600f9fedf2cfd69cdd2cb4bde4a9b39ce2873Ted Kremenek 86006de276fff91264437fa75111ed76de43097e089Ted Kremenek // Our "symbolic interpreter" is just a dispatch off the currently 86106de276fff91264437fa75111ed76de43097e089Ted Kremenek // viewed AST node. We then recursively traverse the AST by calling 86206de276fff91264437fa75111ed76de43097e089Ted Kremenek // EvalAddr and EvalVal appropriately. 86306de276fff91264437fa75111ed76de43097e089Ted Kremenek switch (E->getStmtClass()) { 86406de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::DeclRefExprClass: { 86506de276fff91264437fa75111ed76de43097e089Ted Kremenek // DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking 86606de276fff91264437fa75111ed76de43097e089Ted Kremenek // at code that refers to a variable's name. We check if it has local 86706de276fff91264437fa75111ed76de43097e089Ted Kremenek // storage within the function, and if so, return the expression. 86806de276fff91264437fa75111ed76de43097e089Ted Kremenek DeclRefExpr *DR = cast<DeclRefExpr>(E); 86906de276fff91264437fa75111ed76de43097e089Ted Kremenek 87006de276fff91264437fa75111ed76de43097e089Ted Kremenek if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl())) 87106de276fff91264437fa75111ed76de43097e089Ted Kremenek if(V->hasLocalStorage()) return DR; 87206de276fff91264437fa75111ed76de43097e089Ted Kremenek 87306de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 87406de276fff91264437fa75111ed76de43097e089Ted Kremenek } 87506de276fff91264437fa75111ed76de43097e089Ted Kremenek 87606de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ParenExprClass: 87706de276fff91264437fa75111ed76de43097e089Ted Kremenek // Ignore parentheses. 87806de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalVal(cast<ParenExpr>(E)->getSubExpr()); 87906de276fff91264437fa75111ed76de43097e089Ted Kremenek 88006de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::UnaryOperatorClass: { 88106de276fff91264437fa75111ed76de43097e089Ted Kremenek // The only unary operator that make sense to handle here 88206de276fff91264437fa75111ed76de43097e089Ted Kremenek // is Deref. All others don't resolve to a "name." This includes 88306de276fff91264437fa75111ed76de43097e089Ted Kremenek // handling all sorts of rvalues passed to a unary operator. 88406de276fff91264437fa75111ed76de43097e089Ted Kremenek UnaryOperator *U = cast<UnaryOperator>(E); 88506de276fff91264437fa75111ed76de43097e089Ted Kremenek 88606de276fff91264437fa75111ed76de43097e089Ted Kremenek if (U->getOpcode() == UnaryOperator::Deref) 88706de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalAddr(U->getSubExpr()); 88806de276fff91264437fa75111ed76de43097e089Ted Kremenek 88906de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 89006de276fff91264437fa75111ed76de43097e089Ted Kremenek } 89106de276fff91264437fa75111ed76de43097e089Ted Kremenek 89206de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ArraySubscriptExprClass: { 89306de276fff91264437fa75111ed76de43097e089Ted Kremenek // Array subscripts are potential references to data on the stack. We 89406de276fff91264437fa75111ed76de43097e089Ted Kremenek // retrieve the DeclRefExpr* for the array variable if it indeed 89506de276fff91264437fa75111ed76de43097e089Ted Kremenek // has local storage. 8962324512285caac0332bbbc6e4cab6245d2a370a1Ted Kremenek return EvalAddr(cast<ArraySubscriptExpr>(E)->getBase()); 89706de276fff91264437fa75111ed76de43097e089Ted Kremenek } 89806de276fff91264437fa75111ed76de43097e089Ted Kremenek 89906de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::ConditionalOperatorClass: { 90006de276fff91264437fa75111ed76de43097e089Ted Kremenek // For conditional operators we need to see if either the LHS or RHS are 90106de276fff91264437fa75111ed76de43097e089Ted Kremenek // non-NULL DeclRefExpr's. If one is non-NULL, we return it. 90206de276fff91264437fa75111ed76de43097e089Ted Kremenek ConditionalOperator *C = cast<ConditionalOperator>(E); 90306de276fff91264437fa75111ed76de43097e089Ted Kremenek 9043907323dd6665c0c4e383435cb145233f4533406Anders Carlsson // Handle the GNU extension for missing LHS. 9053907323dd6665c0c4e383435cb145233f4533406Anders Carlsson if (Expr *lhsExpr = C->getLHS()) 9063907323dd6665c0c4e383435cb145233f4533406Anders Carlsson if (DeclRefExpr *LHS = EvalVal(lhsExpr)) 9073907323dd6665c0c4e383435cb145233f4533406Anders Carlsson return LHS; 9083907323dd6665c0c4e383435cb145233f4533406Anders Carlsson 9093907323dd6665c0c4e383435cb145233f4533406Anders Carlsson return EvalVal(C->getRHS()); 91006de276fff91264437fa75111ed76de43097e089Ted Kremenek } 91106de276fff91264437fa75111ed76de43097e089Ted Kremenek 91206de276fff91264437fa75111ed76de43097e089Ted Kremenek // Accesses to members are potential references to data on the stack. 91306de276fff91264437fa75111ed76de43097e089Ted Kremenek case Stmt::MemberExprClass: { 91406de276fff91264437fa75111ed76de43097e089Ted Kremenek MemberExpr *M = cast<MemberExpr>(E); 91506de276fff91264437fa75111ed76de43097e089Ted Kremenek 91606de276fff91264437fa75111ed76de43097e089Ted Kremenek // Check for indirect access. We only want direct field accesses. 91706de276fff91264437fa75111ed76de43097e089Ted Kremenek if (!M->isArrow()) 91806de276fff91264437fa75111ed76de43097e089Ted Kremenek return EvalVal(M->getBase()); 91906de276fff91264437fa75111ed76de43097e089Ted Kremenek else 92006de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 92106de276fff91264437fa75111ed76de43097e089Ted Kremenek } 92206de276fff91264437fa75111ed76de43097e089Ted Kremenek 92306de276fff91264437fa75111ed76de43097e089Ted Kremenek // Everything else: we simply don't reason about them. 92406de276fff91264437fa75111ed76de43097e089Ted Kremenek default: 92506de276fff91264437fa75111ed76de43097e089Ted Kremenek return NULL; 92606de276fff91264437fa75111ed76de43097e089Ted Kremenek } 92706de276fff91264437fa75111ed76de43097e089Ted Kremenek} 928588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 929588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===// 930588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 931588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// Check for comparisons of floating point operands using != and ==. 932588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// Issue a warning if these are no self-comparisons, as they are not likely 933588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek/// to do what the programmer intended. 934588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenekvoid Sema::CheckFloatComparison(SourceLocation loc, Expr* lex, Expr *rex) { 935588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek bool EmitWarning = true; 936588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 9374e99a5fc3b203397a91136c6e695e405fb8fc606Ted Kremenek Expr* LeftExprSansParen = lex->IgnoreParens(); 93832e97b66bbce16c9e81c877794fb7a0aeeb66ccbTed Kremenek Expr* RightExprSansParen = rex->IgnoreParens(); 939588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 940588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Special case: check for x == x (which is OK). 941588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Do not emit warnings for such cases. 942588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LeftExprSansParen)) 943588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RightExprSansParen)) 944588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (DRL->getDecl() == DRR->getDecl()) 945588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 946588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 9471b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek 9481b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // Special case: check for comparisons against literals that can be exactly 9491b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // represented by APFloat. In such cases, do not emit a warning. This 9501b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // is a heuristic: often comparison against such literals are used to 9511b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // detect if a value in a variable has not changed. This clearly can 9521b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek // lead to false negatives. 9531b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (EmitWarning) { 9541b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FloatingLiteral* FLL = dyn_cast<FloatingLiteral>(LeftExprSansParen)) { 9551b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FLL->isExact()) 9561b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek EmitWarning = false; 9571b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9581b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek else 9591b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FloatingLiteral* FLR = dyn_cast<FloatingLiteral>(RightExprSansParen)){ 9601b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek if (FLR->isExact()) 9611b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek EmitWarning = false; 9621b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9631b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek } 9641b500bb0d40aa3ebf1ace47340bb5f401a9ae99cTed Kremenek 965588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Check for comparisons with builtin types. 966588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 967588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (CallExpr* CL = dyn_cast<CallExpr>(LeftExprSansParen)) 968588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (isCallBuiltin(CL)) 969588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 970588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 971588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 972588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (CallExpr* CR = dyn_cast<CallExpr>(RightExprSansParen)) 973588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (isCallBuiltin(CR)) 974588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek EmitWarning = false; 975588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek 976588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek // Emit the diagnostic. 977588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek if (EmitWarning) 978588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek Diag(loc, diag::warn_floatingpoint_eq, 979588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek lex->getSourceRange(),rex->getSourceRange()); 980588e5ebee2db045c3611e0c8f601bc4495ebd0f3Ted Kremenek} 981