Author: hans Date: Mon Sep 29 18:06:57 2014 New Revision: 218640 URL: http://llvm.org/viewvc/llvm-project?rev=218640&view=rev Log: Don't trap when passing non-POD arguments to variadic functions in MS-compatibility mode
Clang warns (treated as error by default, but still ignored in system headers) when passing non-POD arguments to variadic functions, and generates a trap instruction to crash the program if that code is ever run. Unfortunately, MSVC happily generates code for such calls without a warning, and there is code in system headers that use it. This makes Clang not insert the trap instruction when in -fms-compatibility mode, while still generating the warning/error message. Differential Revision: http://reviews.llvm.org/D5492 Added: cfe/trunk/test/CodeGenCXX/vararg-non-pod-ms-compat.cpp Modified: cfe/trunk/include/clang/Sema/Sema.h cfe/trunk/lib/Sema/SemaChecking.cpp cfe/trunk/lib/Sema/SemaExpr.cpp cfe/trunk/test/SemaCXX/vararg-non-pod.cpp Modified: cfe/trunk/include/clang/Sema/Sema.h URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=218640&r1=218639&r2=218640&view=diff ============================================================================== --- cfe/trunk/include/clang/Sema/Sema.h (original) +++ cfe/trunk/include/clang/Sema/Sema.h Mon Sep 29 18:06:57 2014 @@ -7737,6 +7737,7 @@ public: VAK_Valid, VAK_ValidInCXX11, VAK_Undefined, + VAK_MSVCUndefined, VAK_Invalid }; Modified: cfe/trunk/lib/Sema/SemaChecking.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=218640&r1=218639&r2=218640&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaChecking.cpp (original) +++ cfe/trunk/lib/Sema/SemaChecking.cpp Mon Sep 29 18:06:57 2014 @@ -3569,6 +3569,7 @@ CheckPrintfHandler::checkFormatExpr(cons break; case Sema::VAK_Undefined: + case Sema::VAK_MSVCUndefined: EmitFormatDiagnostic( S.PDiag(diag::warn_non_pod_vararg_with_format_string) << S.getLangOpts().CPlusPlus11 Modified: cfe/trunk/lib/Sema/SemaExpr.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=218640&r1=218639&r2=218640&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaExpr.cpp (original) +++ cfe/trunk/lib/Sema/SemaExpr.cpp Mon Sep 29 18:06:57 2014 @@ -800,6 +800,9 @@ Sema::VarArgKind Sema::isValidVarArgType if (Ty->isObjCObjectType()) return VAK_Invalid; + if (getLangOpts().MSVCCompat) + return VAK_MSVCUndefined; + // FIXME: In C++11, these cases are conditionally-supported, meaning we're // permitted to reject them. We should consider doing so. return VAK_Undefined; @@ -829,6 +832,7 @@ void Sema::checkVariadicArgument(const E break; case VAK_Undefined: + case VAK_MSVCUndefined: DiagRuntimeBehavior( E->getLocStart(), nullptr, PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) Added: cfe/trunk/test/CodeGenCXX/vararg-non-pod-ms-compat.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/vararg-non-pod-ms-compat.cpp?rev=218640&view=auto ============================================================================== --- cfe/trunk/test/CodeGenCXX/vararg-non-pod-ms-compat.cpp (added) +++ cfe/trunk/test/CodeGenCXX/vararg-non-pod-ms-compat.cpp Mon Sep 29 18:06:57 2014 @@ -0,0 +1,26 @@ +// RUN: %clang_cc1 -Wno-error=non-pod-varargs -triple i686-pc-win32 -fms-compatibility -emit-llvm -o - %s | FileCheck %s -check-prefix=X86 -check-prefix=CHECK +// RUN: %clang_cc1 -Wno-error=non-pod-varargs -triple x86_64-pc-win32 -fms-compatibility -emit-llvm -o - %s | FileCheck %s -check-prefix=X64 -check-prefix=CHECK + +struct X { + X(); + ~X(); + int data; +}; + +void vararg(...); + +void test(X x) { + // CHECK-LABEL: define void @"\01?test@@YAXUX@@@Z" + + // X86: %[[argmem:[^ ]*]] = alloca inalloca <{ %struct.X }> + // X86: call void (<{ %struct.X }>*, ...)* bitcast (void (...)* @"\01?vararg@@YAXZZ" to void (<{ %struct.X }>*, ...)*)(<{ %struct.X }>* inalloca %[[argmem]]) + + // X64: %[[valptr:[^ ]*]] = getelementptr %struct.X* %{{[^ ]*}}, i32 0, i32 0 + // X64: %[[val:[^ ]*]] = load i32* %[[valptr]] + // X64: call void (...)* @"\01?vararg@@YAXZZ"(i32 %[[val]]) + + // CHECK-NOT: llvm.trap + vararg(x); + // CHECK: ret void +} + Modified: cfe/trunk/test/SemaCXX/vararg-non-pod.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/vararg-non-pod.cpp?rev=218640&r1=218639&r2=218640&view=diff ============================================================================== --- cfe/trunk/test/SemaCXX/vararg-non-pod.cpp (original) +++ cfe/trunk/test/SemaCXX/vararg-non-pod.cpp Mon Sep 29 18:06:57 2014 @@ -1,5 +1,8 @@ // RUN: %clang_cc1 -fsyntax-only -verify -fblocks %s -Wno-error=non-pod-varargs +// Check that the warning is still there under -fms-compatibility. +// RUN: %clang_cc1 -fsyntax-only -verify -fblocks %s -Wno-error=non-pod-varargs -fms-compatibility + extern char version[]; class C { _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
