From: Bill Wendling Date: Wed, 20 Nov 2013 06:46:42 +0000 (+0000) Subject: Merging r195168: X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7b0fe5d62cc31a61188a20b243794b800baa3e7e;p=clang Merging r195168: ------------------------------------------------------------------------ r195168 | rnk | 2013-11-19 15:23:00 -0800 (Tue, 19 Nov 2013) | 17 lines Add a mangler entry point for TBAA rather than using RTTI directly Summary: RTTI is not yet implemented for the Microsoft C++ ABI and isn't expected soon. We could easily add the mangling, but the error is what prevents us from silently miscompiling code that expects RTTI. Instead, add a new mangleTypeName entry point that simply forwards to mangleName or mangleType to produce a string that isn't part of the ABI. Itanium can continue to use RTTI names to avoid unecessary test breakage. This also seems like the right design. The fact that TBAA names happen to be RTTI names is now an implementation detail of the mangler, rather than part of TBAA. Differential Revision: http://llvm-reviews.chandlerc.com/D2153 ------------------------------------------------------------------------ git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_34@195227 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/clang/AST/Mangle.h b/include/clang/AST/Mangle.h index e875c31fc0..4df2955aec 100644 --- a/include/clang/AST/Mangle.h +++ b/include/clang/AST/Mangle.h @@ -148,6 +148,12 @@ public: virtual void mangleDynamicAtExitDestructor(const VarDecl *D, raw_ostream &) = 0; + /// Generates a unique string for an externally visible type for use with TBAA + /// or type uniquing. + /// TODO: Extend this to internal types by generating names that are unique + /// across translation units so it can be used with LTO. + virtual void mangleTypeName(QualType T, raw_ostream &) = 0; + /// @} }; diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp index e94b4cf907..0621d7b1ad 100644 --- a/lib/AST/ItaniumMangle.cpp +++ b/lib/AST/ItaniumMangle.cpp @@ -144,6 +144,7 @@ public: raw_ostream &); void mangleCXXRTTI(QualType T, raw_ostream &); void mangleCXXRTTIName(QualType T, raw_ostream &); + void mangleTypeName(QualType T, raw_ostream &); void mangleCXXCtor(const CXXConstructorDecl *D, CXXCtorType Type, raw_ostream &); void mangleCXXDtor(const CXXDestructorDecl *D, CXXDtorType Type, @@ -3784,6 +3785,10 @@ void ItaniumMangleContextImpl::mangleCXXRTTIName(QualType Ty, Mangler.mangleType(Ty); } +void ItaniumMangleContextImpl::mangleTypeName(QualType Ty, raw_ostream &Out) { + mangleCXXRTTIName(Ty, Out); +} + ItaniumMangleContext * ItaniumMangleContext::create(ASTContext &Context, DiagnosticsEngine &Diags) { return new ItaniumMangleContextImpl(Context, Diags); diff --git a/lib/AST/MicrosoftMangle.cpp b/lib/AST/MicrosoftMangle.cpp index ff1b0158c5..ed7168e3eb 100644 --- a/lib/AST/MicrosoftMangle.cpp +++ b/lib/AST/MicrosoftMangle.cpp @@ -197,6 +197,7 @@ public: raw_ostream &Out); virtual void mangleCXXRTTI(QualType T, raw_ostream &); virtual void mangleCXXRTTIName(QualType T, raw_ostream &); + virtual void mangleTypeName(QualType T, raw_ostream &); virtual void mangleCXXCtor(const CXXConstructorDecl *D, CXXCtorType Type, raw_ostream &); virtual void mangleCXXDtor(const CXXDestructorDecl *D, CXXDtorType Type, @@ -2019,6 +2020,14 @@ void MicrosoftMangleContextImpl::mangleCXXRTTIName(QualType T, raw_ostream &) { << T.getBaseTypeIdentifier(); } +void MicrosoftMangleContextImpl::mangleTypeName(QualType T, raw_ostream &Out) { + // This is just a made up unique string for the purposes of tbaa. undname + // does *not* know how to demangle it. + MicrosoftCXXNameMangler Mangler(*this, Out); + Mangler.getStream() << '?'; + Mangler.mangleType(T, SourceRange()); +} + void MicrosoftMangleContextImpl::mangleCXXCtor(const CXXConstructorDecl *D, CXXCtorType Type, raw_ostream &Out) { diff --git a/lib/CodeGen/CodeGenTBAA.cpp b/lib/CodeGen/CodeGenTBAA.cpp index 11e376ff40..699cc2eabe 100644 --- a/lib/CodeGen/CodeGenTBAA.cpp +++ b/lib/CodeGen/CodeGenTBAA.cpp @@ -152,11 +152,9 @@ CodeGenTBAA::getTBAAInfo(QualType QTy) { if (!Features.CPlusPlus || !ETy->getDecl()->isExternallyVisible()) return MetadataCache[Ty] = getChar(); - // TODO: This is using the RTTI name. Is there a better way to get - // a unique string for a type? SmallString<256> OutName; llvm::raw_svector_ostream Out(OutName); - MContext.mangleCXXRTTIName(QualType(ETy, 0), Out); + MContext.mangleTypeName(QualType(ETy, 0), Out); Out.flush(); return MetadataCache[Ty] = createTBAAScalarType(OutName, getChar()); } @@ -268,13 +266,11 @@ CodeGenTBAA::getTBAAStructTypeInfo(QualType QTy) { FieldNode, Layout.getFieldOffset(idx) / Context.getCharWidth())); } - // TODO: This is using the RTTI name. Is there a better way to get - // a unique string for a type? SmallString<256> OutName; if (Features.CPlusPlus) { - // Don't use mangleCXXRTTIName for C code. + // Don't use the mangler for C code. llvm::raw_svector_ostream Out(OutName); - MContext.mangleCXXRTTIName(QualType(Ty, 0), Out); + MContext.mangleTypeName(QualType(Ty, 0), Out); Out.flush(); } else { OutName = RD->getName(); diff --git a/test/CodeGen/tbaa-ms-abi.cpp b/test/CodeGen/tbaa-ms-abi.cpp new file mode 100644 index 0000000000..67390b1a8a --- /dev/null +++ b/test/CodeGen/tbaa-ms-abi.cpp @@ -0,0 +1,22 @@ +// RUN: %clang_cc1 -cxx-abi microsoft -triple i686-pc-win32 -disable-llvm-optzns -emit-llvm -o - -O1 %s | FileCheck %s +// +// Test that TBAA works in the Microsoft C++ ABI. We used to error out while +// attempting to mangle RTTI. + +struct StructA { + int a; +}; + +struct StructB : virtual StructA { + StructB(); +}; + +StructB::StructB() { + a = 42; +// CHECK: store i32 42, i32* {{.*}}, !tbaa [[TAG_A_i32:!.*]] +} + +// CHECK: [[TYPE_CHAR:!.*]] = metadata !{metadata !"omnipotent char", metadata +// CHECK: [[TYPE_INT:!.*]] = metadata !{metadata !"int", metadata [[TYPE_CHAR]], i64 0} +// CHECK: [[TAG_A_i32]] = metadata !{metadata [[TYPE_A:!.*]], metadata [[TYPE_INT]], i64 0} +// CHECK: [[TYPE_A]] = metadata !{metadata !"?AUStructA@@", metadata [[TYPE_INT]], i64 0}