Revert "[Clang] skip default argument instantiation for non-defining friend declarations without specialization info to meet [dcl.fct.default] p4"

[mizvekov]

Reverts #113777

Reverted due to regression reported here: #113777 (comment)

[llvmbot]

@llvm/pr-subscribers-clang

Author: Matheus Izvekov (mizvekov)

Changes

Reverts llvm/llvm-project#113777

Reverted due to regression reported here: #113777 (comment)

---

Full diff: https://github.com/llvm/llvm-project/pull/115404.diff

3 Files Affected:

• (modified) clang/docs/ReleaseNotes.rst (-2)
• (modified) clang/lib/Sema/SemaExpr.cpp (-11)
• (modified) clang/test/CXX/temp/temp.res/p4.cpp (-19)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 0b0f2053f634ee..30bcb6313b6ade 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -636,8 +636,6 @@ 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/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index 68527d9da8c799..01d43317e33aed 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -6018,17 +6018,6 @@ bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, FunctionDecl *FDecl, } else { assert(Param && "can't use default arguments without a known callee"); - // 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 (FDecl->getFriendObjectKind() != Decl::FOK_None && - FDecl->getMemberSpecializationInfo() == nullptr) - return true; - ExprResult ArgExpr = BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); if (ArgExpr.isInvalid()) return true; diff --git a/clang/test/CXX/temp/temp.res/p4.cpp b/clang/test/CXX/temp/temp.res/p4.cpp index 743ffed14d81a8..f54d8649f5da88 100644 --- a/clang/test/CXX/temp/temp.res/p4.cpp +++ b/clang/test/CXX/temp/temp.res/p4.cpp @@ -185,22 +185,3 @@ template<typename T> struct S { friend void X::f(T::type); }; } - -namespace GH113324 { -template <typename = int> struct ct { - friend void f1(ct, int = 0); // expected-error {{friend declaration specifying a default argument must be a definition}} - friend void f2(ct a, ct = decltype(a){ }); // expected-error {{friend declaration specifying a default argument must be a definition}} -}; - -template<class T> using alias = int; -template<typename T> struct C { - // FIXME: We miss diagnosing the default argument instantiation failure (forming reference to void) - friend void f3(C, int a = alias<T&>(1)); // expected-error {{friend declaration specifying a default argument must be a definition}} -}; - -void test() { - f1(ct<>{}); - f2(ct<>{}); - f3(C<void>()); -} -} // namespace GH113324