llvm-project/clang
Dimitry Andric c7bc461298 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 <string>

$ 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<char> 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<wchar_t> 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<char16_t> 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<char32_t> 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<char> 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<wchar_t> 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<char16_t> 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<char32_t> 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

llvm-svn: 320755
2017-12-14 22:32:24 +00:00
..
INPUTS
bindings [libclang] Add support for checking abstractness of records 2017-12-14 22:01:50 +00:00
cmake Update Clang CMake cache to use cxx-headers, NFC 2017-12-09 23:44:42 +00:00
docs Harmonize GNU- and C++-style attribute spellings. 2017-12-14 22:17:09 +00:00
examples [CMake] Use PRIVATE in target_link_libraries for executables 2017-12-05 21:49:56 +00:00
include Harmonize GNU- and C++-style attribute spellings. 2017-12-14 22:17:09 +00:00
lib Don't trigger -Wuser-defined-literals for system headers 2017-12-14 22:32:24 +00:00
runtime [clang] Use add_llvm_install_targets 2017-11-30 22:35:02 +00:00
test Don't trigger -Wuser-defined-literals for system headers 2017-12-14 22:32:24 +00:00
tools [libclang] Add support for checking abstractness of records 2017-12-14 22:01:50 +00:00
unittests Revert "[ClangFormat] IndentWrappedFunctionNames should be true in the google ObjC style" 2017-12-14 21:44:11 +00:00
utils Determine the attribute subject for diagnostics based on declarative information in DeclNodes.td. This greatly reduces the number of enumerated values used for more complex diagnostics; these are now only required when the "attribute only applies to" diagnostic needs to be generated manually as part of semantic processing. 2017-11-26 20:01:12 +00:00
www Update website to mention that you still need -frelaxed-template-template-args to enable the corresponding C++17 feature in Clang 5. 2017-11-30 23:07:29 +00:00
.arcconfig [clang] Set up .arcconfig to point to new Diffusion C repository 2017-11-27 17:21:24 +00:00
.clang-format
.clang-tidy
.gitignore
CMakeLists.txt [OpenMP] NVPTX: Set default/minimum compute capability to sm_35 2017-12-07 20:27:31 +00:00
CODE_OWNERS.TXT Change code owner for Clang Static Analyzer to Devin Coughlin. 2017-11-17 23:19:04 +00:00
INSTALL.txt
LICENSE.TXT
ModuleInfo.txt
NOTES.txt
README.txt Test commit 2017-10-21 16:03:17 +00:00

README.txt

//===----------------------------------------------------------------------===//
// C Language Family Front-end
//===----------------------------------------------------------------------===//

Welcome to Clang.  This is a compiler front-end for the C family of languages
(C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM
compiler infrastructure project.

Unlike many other compiler frontends, Clang is useful for a number of things
beyond just compiling code: we intend for Clang to be host to a number of
different source-level tools.  One example of this is the Clang Static Analyzer.

If you're interested in more (including how to build Clang) it is best to read
the relevant web sites.  Here are some pointers:

Information on Clang:             http://clang.llvm.org/
Building and using Clang:         http://clang.llvm.org/get_started.html
Clang Static Analyzer:            http://clang-analyzer.llvm.org/
Information on the LLVM project:  http://llvm.org/

If you have questions or comments about Clang, a great place to discuss them is
on the Clang development mailing list:
  http://lists.llvm.org/mailman/listinfo/cfe-dev

If you find a bug in Clang, please file it in the LLVM bug tracker:
  http://llvm.org/bugs/