From: Dimitry Andric Date: Thu, 14 Dec 2017 22:32:24 +0000 (+0000) Subject: Don't trigger -Wuser-defined-literals for system headers X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9e92ae2496f49efdc169a8da26ba13ba85e62378;p=clang Don't trigger -Wuser-defined-literals for system headers Summary: In D41064, I proposed adding `#pragma clang diagnostic ignored "-Wuser-defined-literals"` to some of libc++'s headers, since these warnings are now triggered by clang's new `-std=gnu++14` default: ``` $ cat test.cpp #include $ clang -std=c++14 -Wsystem-headers -Wall -Wextra -c test.cpp In file included from test.cpp:1: In file included from /usr/include/c++/v1/string:470: /usr/include/c++/v1/string_view:763:29: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals] basic_string_view operator "" sv(const char *__str, size_t __len) ^ /usr/include/c++/v1/string_view:769:32: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals] basic_string_view operator "" sv(const wchar_t *__str, size_t __len) ^ /usr/include/c++/v1/string_view:775:33: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals] basic_string_view operator "" sv(const char16_t *__str, size_t __len) ^ /usr/include/c++/v1/string_view:781:33: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals] basic_string_view operator "" sv(const char32_t *__str, size_t __len) ^ In file included from test.cpp:1: /usr/include/c++/v1/string:4012:24: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals] basic_string operator "" s( const char *__str, size_t __len ) ^ /usr/include/c++/v1/string:4018:27: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals] basic_string operator "" s( const wchar_t *__str, size_t __len ) ^ /usr/include/c++/v1/string:4024:28: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals] basic_string operator "" s( const char16_t *__str, size_t __len ) ^ /usr/include/c++/v1/string:4030:28: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals] basic_string operator "" s( const char32_t *__str, size_t __len ) ^ 8 warnings generated. ``` Both @aaron.ballman and @mclow.lists felt that adding this workaround to the libc++ headers was the wrong way, and it should be fixed in clang instead. Here is a proposal to do just that. I verified that this suppresses the warning, even when -Wsystem-headers is used, and that the warning is still emitted for a declaration outside of system headers. Reviewers: aaron.ballman, mclow.lists, rsmith Reviewed By: aaron.ballman Subscribers: mclow.lists, aaron.ballman, andrew, emaste, cfe-commits Differential Revision: https://reviews.llvm.org/D41080 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@320755 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp index 5a5874ee7a..497713f660 100644 --- a/lib/Sema/SemaDeclCXX.cpp +++ b/lib/Sema/SemaDeclCXX.cpp @@ -13076,7 +13076,8 @@ bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) { StringRef LiteralName = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName(); - if (LiteralName[0] != '_') { + if (LiteralName[0] != '_' && + !getSourceManager().isInSystemHeader(FnDecl->getLocation())) { // C++11 [usrlit.suffix]p1: // Literal suffix identifiers that do not start with an underscore // are reserved for future standardization. diff --git a/test/SemaCXX/no-warn-user-defined-literals-in-system-headers.cpp b/test/SemaCXX/no-warn-user-defined-literals-in-system-headers.cpp new file mode 100644 index 0000000000..ee5b0c47b9 --- /dev/null +++ b/test/SemaCXX/no-warn-user-defined-literals-in-system-headers.cpp @@ -0,0 +1,5 @@ +// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -Wsystem-headers -isystem %S %s + +#include + +void operator "" bar(long double); // expected-warning{{user-defined literal suffixes not starting with '_' are reserved}} diff --git a/test/SemaCXX/no-warn-user-defined-literals-in-system-headers.h b/test/SemaCXX/no-warn-user-defined-literals-in-system-headers.h new file mode 100644 index 0000000000..d1e2583168 --- /dev/null +++ b/test/SemaCXX/no-warn-user-defined-literals-in-system-headers.h @@ -0,0 +1,2 @@ +// Header for no-warn-user-defined-literals-in-system-headers.cpp +void operator "" foo (const char *);