llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Oleksandr T. (a-tarasyuk) <details> <summary>Changes</summary> Fixes #<!-- -->113324 --- https://github.com/llvm/llvm-project/pull/113777#issuecomment-2463960195 https://github.com/llvm/llvm-project/pull/113777#issuecomment-2464234180 --- Full diff: https://github.com/llvm/llvm-project/pull/115487.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+2) - (modified) clang/lib/Sema/SemaTemplateInstantiateDecl.cpp (+11) - (modified) clang/test/CXX/temp/temp.res/p4.cpp (+43) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index d4bf05651a63eb..a3bce0e77581fb 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -641,6 +641,8 @@ Bug Fixes to C++ Support an implicitly instantiated class template specialization. (#GH51051) - Fixed an assertion failure caused by invalid enum forward declarations. (#GH112208) - Name independent data members were not correctly initialized from default member initializers. (#GH114069) +- Fixed an assertion failure caused by invalid default argument substitutions in non-defining + friend declarations. (#GH113324). Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp index 5a001843e2ba46..0bbab95001ad8e 100644 --- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp +++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp @@ -4694,6 +4694,17 @@ bool Sema::InstantiateDefaultArgument(SourceLocation CallLoc, FunctionDecl *FD, ParmVarDecl *Param) { assert(Param->hasUninstantiatedDefaultArg()); + // FIXME: We don't track member specialization info for non-defining + // friend declarations, so we will not be able to later find the function + // pattern. As a workaround, don't instantiate the default argument in this + // case. This is correct per wording and only an error recovery issue, as per + // [dcl.fct.default]p4: + // if a friend declaration D specifies a default argument expression, + // that declaration shall be a definition. + if (FD->getFriendObjectKind() != Decl::FOK_None && + !FD->getTemplateInstantiationPattern()) + return true; + // Instantiate the expression. // // FIXME: Pass in a correct Pattern argument, otherwise diff --git a/clang/test/CXX/temp/temp.res/p4.cpp b/clang/test/CXX/temp/temp.res/p4.cpp index f54d8649f5da88..cf6c45b4c351c5 100644 --- a/clang/test/CXX/temp/temp.res/p4.cpp +++ b/clang/test/CXX/temp/temp.res/p4.cpp @@ -185,3 +185,46 @@ template<typename T> struct S { friend void X::f(T::type); }; } + +namespace GH113324 { +template <typename = int> struct S1 { + friend void f1(S1, int = 0); // expected-error {{friend declaration specifying a default argument must be a definition}} + friend void f2(S1 a, S1 = decltype(a){}); // expected-error {{friend declaration specifying a default argument must be a definition}} +}; + +template <class T> using alias = int; +template <typename T> struct S2 { + // FIXME: We miss diagnosing the default argument instantiation failure + // (forming reference to void) + friend void f3(S2, int a = alias<T &>(1)); // expected-error {{friend declaration specifying a default argument must be a definition}} +}; + +struct S3 { + friend void f4(S3, int = 42) { } +}; + +template <bool, class> using __enable_if_t = int; +template <int v> struct S4 { + static const int value = v; +}; +struct S5 { + template <__enable_if_t<S4<true>::value, int> = 0> + S5(const char *); +}; +struct S6 { + template <typename a, typename b> + friend void f5(int, S6, a, b, S5 = "") { } +}; + +void test() { + f1(S1<>{}); + f2(S1<>{}); + f3(S2<void>()); + + S3 s3; + f4(s3); + + S6 s6; + auto result = f5(0, s6, [] {}, [] {}); // expected-error {{variable has incomplete type 'void}} +} +} // namespace GH113324 `````````` </details> https://github.com/llvm/llvm-project/pull/115487 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
