-
Notifications
You must be signed in to change notification settings - Fork 2.4k
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Fix std::variant, std::filesystem::path tests on GCC-8, Clang-7,8. #2951
Conversation
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Thanks for the PR. Unfortunately it only masks the issue so I suggest including <variant>
in fmt/std.h
when the header exists instead. This can be checked with FMT_HAS_INCLUDE
.
2581e91
to
1ec4b82
Compare
@vitaut, Done. |
@@ -17,10 +17,16 @@ | |||
#if FMT_HAS_INCLUDE(<version>) | |||
# include <version> | |||
#endif | |||
#if FMT_CPLUSPLUS >= 201703L |
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
What is this check for? Shouldn't FMT_HAS_INCLUDE
and feature test macro checks be enough?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Without FMT_CPLUSPLUS
check:
libstdc++
: ok (Checking the version of C++ standard is present)
libcxx
: ok (Checking the version of C++ standard is absent)
MSVC
message:
#if !_HAS_CXX17
#pragma message("The contents of <filesystem> are available only with C++17 or later.")
#else // ^^^ !_HAS_CXX17 / _HAS_CXX17 vvv
https://github.com/microsoft/STL/blob/c34f24920e463a71791c2ee3d2bed14926518965/stl/inc/filesystem#L12-L14
https://github.com/microsoft/STL/blob/c34f24920e463a71791c2ee3d2bed14926518965/stl/inc/variant#L12-L14
https://godbolt.org/z/1MM9Kee8n
For this reason, a check is required.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Could you add a short comment clarifying that this check is for MSVC?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
@vitaut Done
test/CMakeLists.txt
Outdated
try_compile(compile_result_unused | ||
${CMAKE_CURRENT_BINARY_DIR} | ||
SOURCES ${CMAKE_CURRENT_LIST_DIR}/detect-stdfs.cc | ||
CMAKE_FLAGS CMAKE_OSX_ARCHITECTURES=${CMAKE_OSX_ARCHITECTURES} | ||
OUTPUT_VARIABLE RAWOUTPUT) | ||
string(REGEX REPLACE ".*libfound \"([^\"]*)\".*" "\\1" STDLIBFS "${RAWOUTPUT}") | ||
if (STDLIBFS) | ||
target_link_libraries(std-test ${STDLIBFS}) | ||
endif () |
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Is it possible to simplify this?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
The FS-library name is determined by the version of the C++ Standard Library.
CMake only determine the compiler version.
Clang supports libstdc++
and libcxx
.
Intel C++ supports libstdc++
on Linux, libcxx
on macOS, and Microsoft STL on Windows.
Therefore, the only way to determine which standard library is actually used is by compiling the code.
The code I wrote is the easiest way I know.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Can this information be derived from CMAKE_CXX_STANDARD_LIBRARIES
or CMAKE_CXX_IMPLICIT_LINK_LIBRARIES
?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
The variable CMAKE_CXX_IMPLICIT_LINK_LIBRARIES
allows to detect the standard library name, but not its version.
Example:
GCC-8:
CMAKE_CXX_IMPLICIT_LINK_LIBRARIES: stdc++;m;gcc_s;gcc;c;gcc_s;gcc
GCC-9:
CMAKE_CXX_IMPLICIT_LINK_LIBRARIES: stdc++;m;gcc_s;gcc;c;gcc_s;gcc
Clang 13 + libstdc++ (from GCC-11):
CMAKE_CXX_IMPLICIT_LINK_LIBRARIES: stdc++;m;gcc_s;gcc;c;gcc_s;gcc
Clang 13 + libc++:
CMAKE_CXX_IMPLICIT_LINK_LIBRARIES: c++;m;gcc_s;gcc;c;gcc_s;gcc
CMAKE_CXX_STANDARD_LIBRARIES
- CMake 3.6+ and empty in most configurations
test/detect-stdfs.cc
Outdated
// | ||
// For the license information refer to format.h. | ||
|
||
#include <exception> |
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
This include looks unused.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
The macros _GLIBCXX_RELEASE
and _LIBCPP_VERSION
is defined in standard library header files.
<exception>
is the smallest of the standard library header files.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I see. Maybe include <initializer_list>
which is slightly cheaper according to https://artificial-mind.net/projects/compile-health/ and add a comment that this is for _GLIBCXX_RELEASE
& _LIBCPP_VERSION
?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
<initializer_list>
is C++11.
Specifying the version of the standard will complicate the call to try_compile
.
Comment added.
test/CMakeLists.txt
Outdated
try_compile(compile_result_unused | ||
${CMAKE_CURRENT_BINARY_DIR} | ||
SOURCES ${CMAKE_CURRENT_LIST_DIR}/detect-stdfs.cc | ||
CMAKE_FLAGS CMAKE_OSX_ARCHITECTURES=${CMAKE_OSX_ARCHITECTURES} |
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
What is this for?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Compiling detect-stdfs.cc
and read compiler output to get fslib info from error message.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I mean specifically the above line that forwards CMAKE_OSX_ARCHITECTURES
.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
CMAKE_OSX_ARCHITECTURES
affects the compiler but I'm not sure if it affects the standard library as well.
Removed it.
Signed-off-by: Vladislav Shchapov <vladislav@shchapov.ru>
Signed-off-by: Vladislav Shchapov <vladislav@shchapov.ru>
Merged, thanks! |
libstdc++
from GCC-8 support std::variant.libstdc++
from GCC-8 has no<version>
file.libstdc++
from GCC-8 defines the macro__cpp_lib_variant
in<variant>
.fmt/test/gtest/gtest/gtest.h
Lines 2621 to 2627 in 6a775e9
Because
gtest.h
include<variant>
, then the macro__cpp_lib_variant
is defined in the test, but is not defined in"fmt/std.h"
.