https://github.com/charmitro updated https://github.com/llvm/llvm-project/pull/74510
>From 83d29e896b7ae0b5b259cbf179143e526dc37b1c Mon Sep 17 00:00:00 2001 From: Charalampos Mitrodimas <charmi...@posteo.net> Date: Tue, 5 Dec 2023 11:46:56 +0200 Subject: [PATCH] [clang] Disable missing definition warning on pure virtual functions Warning '-Wundefined-func-template' incorrectly indicates that no definition is available for a pure virtual function. However, a definition is not needed for a pure virtual function. Fixes #74016 Signed-off-by: Charalampos Mitrodimas <charmi...@posteo.net> --- clang/docs/ReleaseNotes.rst | 3 ++ .../lib/Sema/SemaTemplateInstantiateDecl.cpp | 3 +- .../instantiate-pure-virtual-function.cpp | 48 +++++++++++++++++++ 3 files changed, 53 insertions(+), 1 deletion(-) create mode 100644 clang/test/SemaTemplate/instantiate-pure-virtual-function.cpp diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 828dd10e3d6db..10dce199b9fd1 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -514,6 +514,9 @@ Improvements to Clang's time-trace Bug Fixes in This Version ------------------------- +- Clang's ``-Wundefined-func-template`` no longer warns on pure virtual + functions. + (`#74016 <https://github.com/llvm/llvm-project/issues/74016>`_) - Fixed an issue where a class template specialization whose declaration is instantiated in one module and whose definition is instantiated in another module may end up with members associated with the wrong declaration of the diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp index d768bb72e07c0..a034de0697b2b 100644 --- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp +++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp @@ -4952,7 +4952,8 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation, std::make_pair(Function, PointOfInstantiation)); } else if (TSK == TSK_ImplicitInstantiation) { if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() && - !getSourceManager().isInSystemHeader(PatternDecl->getBeginLoc())) { + !getSourceManager().isInSystemHeader(PatternDecl->getBeginLoc()) && + !Function->isPure()) { Diag(PointOfInstantiation, diag::warn_func_template_missing) << Function; Diag(PatternDecl->getLocation(), diag::note_forward_template_decl); diff --git a/clang/test/SemaTemplate/instantiate-pure-virtual-function.cpp b/clang/test/SemaTemplate/instantiate-pure-virtual-function.cpp new file mode 100644 index 0000000000000..d188adc9ed034 --- /dev/null +++ b/clang/test/SemaTemplate/instantiate-pure-virtual-function.cpp @@ -0,0 +1,48 @@ +// RUN: %clang_cc1 -fsyntax-only -verify -Wundefined-func-template %s + +namespace GH74016 { + template <typename T> class B { + public: + constexpr void foo(const T &) { bar(1); } + virtual constexpr void bar(unsigned int) = 0; + }; + + template <typename T> class D : public B<T> { + public: + constexpr void bar(unsigned int) override {} + }; + + void test() { + auto t = D<int>(); + t.foo(0); + } +}; + +namespace non_pure_virtual_function { + template <typename T> class B { + public: + constexpr void foo(const T &) { bar(1); } + + virtual constexpr void bar(unsigned int); // expected-warning {{inline function 'non_pure_virtual_function::B<int>::bar' is not defined}} + // expected-note@-1 {{forward declaration of template entity is here}} + // expected-note@-2 {{forward declaration of template entity is here}} + // expected-note@-3 {{forward declaration of template entity is here}} + }; + + template <typename T> class D : public B<T> { // expected-warning {{instantiation of function 'non_pure_virtual_function::B<int>::bar' required here, but no definition is available}} +// expected-warning@-1 {{instantiation of function 'non_pure_virtual_function::B<int>::bar' required here, but no definition is available}} +// expected-warning@-2 {{instantiation of function 'non_pure_virtual_function::B<int>::bar' required here, but no definition is available}} +// expected-note@-3 {{add an explicit instantiation declaration to suppress this warning if 'non_pure_virtual_function::B<int>::bar' is explicitly instantiated in another translation unit}} +// expected-note@-4 {{add an explicit instantiation declaration to suppress this warning if 'non_pure_virtual_function::B<int>::bar' is explicitly instantiated in another translation unit}} +// expected-note@-5 {{add an explicit instantiation declaration to suppress this warning if 'non_pure_virtual_function::B<int>::bar' is explicitly instantiated in another translation unit}} +// expected-note@-6 {{used here}} + + public: + constexpr void bar(unsigned int) override { } + }; + + void test() { + auto t = D<int>(); + t.foo(0); + } +}; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
