Author: David Blaikie Date: 2023-04-04T04:45:32Z New Revision: e9c9db34a9b04706937e9dd764d1d97ca84337b6
URL: https://github.com/llvm/llvm-project/commit/e9c9db34a9b04706937e9dd764d1d97ca84337b6 DIFF: https://github.com/llvm/llvm-project/commit/e9c9db34a9b04706937e9dd764d1d97ca84337b6.diff LOG: PR58819: Correct linkage and mangling of lambdas in inline static member initializers https://llvm.org/pr58819 - clang is giving an externally visible lambda in a static data member internal linkage and the wrong linkage name. Looks like we should be classifying this case the same as a non-static data member, so far as I can tell from the ABI docs and template examples (seems like the non-template inline-defined case should be the same). This is a change in ABI, but not sure it qualifies as an ABI break as far as Apple and Sony are concerned - do you folks want this change? (it should fix the example in the bug where a static member in such a lambda ends up bifurcated, and I don't /think/ it'll break existing code since the symbol was previously internal anyway) Looks like GCC has got this mangling slightly wrong (so we'd still end up with GCC+Clang bifurcation of the local static in the lambda, function address inequality, etc) in that they miss the variable name in the mangling in the non-template case. GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107741 Differential Revision: https://reviews.llvm.org/D138247 Added: Modified: clang/lib/Sema/SemaLambda.cpp clang/test/CodeGenCXX/mangle-lambdas.cpp Removed: ################################################################################ diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp index c633a5080996b..a809968b66032 100644 --- a/clang/lib/Sema/SemaLambda.cpp +++ b/clang/lib/Sema/SemaLambda.cpp @@ -283,12 +283,14 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC) { Normal, DefaultArgument, DataMember, - StaticDataMember, InlineVariable, - VariableTemplate, + TemplatedVariable, Concept } Kind = Normal; + bool IsInNonspecializedTemplate = + inTemplateInstantiation() || CurContext->isDependentContext(); + // Default arguments of member function parameters that appear in a class // definition, as well as the initializers of data members, receive special // treatment. Identify them. @@ -299,15 +301,15 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC) { if (LexicalDC->isRecord()) Kind = DefaultArgument; } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) { - if (Var->getDeclContext()->isRecord()) - Kind = StaticDataMember; - else if (Var->getMostRecentDecl()->isInline()) + if (Var->getMostRecentDecl()->isInline()) Kind = InlineVariable; + else if (Var->getDeclContext()->isRecord() && IsInNonspecializedTemplate) + Kind = TemplatedVariable; else if (Var->getDescribedVarTemplate()) - Kind = VariableTemplate; + Kind = TemplatedVariable; else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) { if (!VTS->isExplicitSpecialization()) - Kind = VariableTemplate; + Kind = TemplatedVariable; } } else if (isa<FieldDecl>(ManglingContextDecl)) { Kind = DataMember; @@ -319,12 +321,9 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC) { // Itanium ABI [5.1.7]: // In the following contexts [...] the one-definition rule requires closure // types in diff erent translation units to "correspond": - bool IsInNonspecializedTemplate = - inTemplateInstantiation() || CurContext->isDependentContext(); switch (Kind) { case Normal: { - // -- the bodies of non-exported nonspecialized template functions - // -- the bodies of inline functions + // -- the bodies of inline or templated functions if ((IsInNonspecializedTemplate && !(ManglingContextDecl && isa<ParmVarDecl>(ManglingContextDecl))) || isInInlineFunction(CurContext)) { @@ -341,21 +340,13 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC) { // however the ManglingContextDecl is important for the purposes of // re-forming the template argument list of the lambda for constraint // evaluation. - case StaticDataMember: - // -- the initializers of nonspecialized static members of template classes - if (!IsInNonspecializedTemplate) - return std::make_tuple(nullptr, ManglingContextDecl); - // Fall through to get the current context. - [[fallthrough]]; - case DataMember: - // -- the in-class initializers of class members + // -- default member initializers case DefaultArgument: // -- default arguments appearing in class definitions case InlineVariable: - // -- the initializers of inline variables - case VariableTemplate: - // -- the initializers of templated variables + case TemplatedVariable: + // -- the initializers of inline or templated variables return std::make_tuple( &Context.getManglingNumberContext(ASTContext::NeedExtraManglingDecl, ManglingContextDecl), diff --git a/clang/test/CodeGenCXX/mangle-lambdas.cpp b/clang/test/CodeGenCXX/mangle-lambdas.cpp index c10f7add32933..5a7de97c91858 100644 --- a/clang/test/CodeGenCXX/mangle-lambdas.cpp +++ b/clang/test/CodeGenCXX/mangle-lambdas.cpp @@ -290,6 +290,17 @@ template void ft4<int>(); // CHECK-LABEL: define linkonce_odr noundef i32 @_ZZZ3ft4IiEvvEN2lc2mfEiEd_NKUlvE_clEv +extern int ExternalVariable; +struct StaticInlineMember { + static constexpr auto x = [] { return ExternalVariable; }; +}; + +// CHECK-LABEL: define void @_Z23test_StaticInlineMemberv +// CHECK: call {{.*}} @_ZNK18StaticInlineMember1xMUlvE_clEv +void test_StaticInlineMember() { + StaticInlineMember::x(); +} + // Check linkage of the various lambdas. // CHECK-LABEL: define linkonce_odr noundef i32 @_ZZ11inline_funciENKUlvE_clEv // CHECK: ret i32 1 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
