Author: rnk Date: Thu Sep 12 10:55:48 2019 New Revision: 371749 URL: http://llvm.org/viewvc/llvm-project?rev=371749&view=rev Log: Don't warn about selectany on implicitly inline variables
Summary: This avoids a -Wignored-attribute warning on the code pattern Microsoft recommends for integral const static data members defined in headers here: https://docs.microsoft.com/en-us/cpp/build/reference/microsoft-extensions-to-c-and-cpp?view=vs-2019 The attribute is redundant, but it is necessary when compiling in C++14 modes with /Za, which disables MSVC's extension that treats such variables as implicitly inline. Fixes PR43270 Reviewers: epastor, thakis, hans Subscribers: cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D67426 Added: cfe/trunk/test/SemaCXX/declspec-selectany.cpp Modified: cfe/trunk/lib/Sema/SemaDecl.cpp Modified: cfe/trunk/lib/Sema/SemaDecl.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=371749&r1=371748&r2=371749&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaDecl.cpp (original) +++ cfe/trunk/lib/Sema/SemaDecl.cpp Thu Sep 12 10:55:48 2019 @@ -2652,6 +2652,15 @@ static void checkNewAttributesAfterDef(S --E; continue; } + } else if (isa<SelectAnyAttr>(NewAttribute) && + cast<VarDecl>(New)->isInline() && + !cast<VarDecl>(New)->isInlineSpecified()) { + // Don't warn about applying selectany to implicitly inline variables. + // Older compilers and language modes would require the use of selectany + // to make such variables inline, and it would have no effect if we + // honored it. + ++I; + continue; } S.Diag(NewAttribute->getLocation(), Added: cfe/trunk/test/SemaCXX/declspec-selectany.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/declspec-selectany.cpp?rev=371749&view=auto ============================================================================== --- cfe/trunk/test/SemaCXX/declspec-selectany.cpp (added) +++ cfe/trunk/test/SemaCXX/declspec-selectany.cpp Thu Sep 12 10:55:48 2019 @@ -0,0 +1,18 @@ +// RUN: %clang_cc1 -std=c++14 %s -triple x86_64-windows-msvc -fdeclspec -verify +// RUN: %clang_cc1 -std=c++17 %s -triple x86_64-windows-msvc -fdeclspec -verify +// RUN: %clang_cc1 -std=c++14 %s -triple x86_64-scei-ps4 -fdeclspec -verify + +// MSVC emits this error too. +const int __declspec(selectany) test1 = 0; // expected-error {{'selectany' can only be applied to data items with external linkage}} + +extern const int test2; +const int test2 = 42; // expected-note {{previous definition is here}} +extern __declspec(selectany) const int test2; // expected-warning {{attribute declaration must precede definition}} + +extern const int test3; +const int __declspec(selectany) test3 = 42; // Standard usage. + +struct Test4 { + static constexpr int sdm = 0; +}; +__declspec(selectany) constexpr int Test4::sdm; // no warning _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits