Author: rakete1111 Date: Sun Jan 27 11:19:59 2019 New Revision: 352323 URL: http://llvm.org/viewvc/llvm-project?rev=352323&view=rev Log: [SemaCXX] Fix ICE with structure bindings to members of template
Summary: Trying to use structure binding with a structure that doesn't implement std::tuple_size, should unpack the data members. When the struct is a template though, clang might hit an assertion (if the type has not been completed before), because CXXRecordDecl::DefinitionData is nullptr. This commit fixes the problem by completing the type while trying to decompose the structured binding. The ICE happens in real world code, for example, when trying to iterate a protobuf generated map with a range-based for loop and structure bindings (because google::protobuf::MapPair is a template and doesn't support std::tuple_size). Reported-by: nicholas....@nlsun.com Patch by Daniele Di Proietto Reviewers: #clang, rsmith Reviewed By: #clang, rsmith Subscribers: cpplearner, Rakete1111, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D56974 Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp cfe/trunk/test/SemaCXX/cxx1z-decomposition.cpp Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=352323&r1=352322&r2=352323&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original) +++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Sun Jan 27 11:19:59 2019 @@ -1300,6 +1300,10 @@ static DeclAccessPair findDecomposableBa static bool checkMemberDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings, ValueDecl *Src, QualType DecompType, const CXXRecordDecl *OrigRD) { + if (S.RequireCompleteType(Src->getLocation(), DecompType, + diag::err_incomplete_type)) + return true; + CXXCastPath BasePath; DeclAccessPair BasePair = findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath); Modified: cfe/trunk/test/SemaCXX/cxx1z-decomposition.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx1z-decomposition.cpp?rev=352323&r1=352322&r2=352323&view=diff ============================================================================== --- cfe/trunk/test/SemaCXX/cxx1z-decomposition.cpp (original) +++ cfe/trunk/test/SemaCXX/cxx1z-decomposition.cpp Sun Jan 27 11:19:59 2019 @@ -81,4 +81,21 @@ struct PR37352 { void f() { static auto [a] = *this; } // expected-error {{cannot be declared 'static'}} }; +namespace instantiate_template { + +template <typename T1, typename T2> +struct pair { + T1 a; + T2 b; +}; + +const pair<int, int> &f1(); + +int f2() { + const auto &[a, b] = f1(); + return a + b; +} + +} // namespace instantiate_template + // FIXME: by-value array copies _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
