With MSVC 14.30 (market name "Visual Studio 2022" [1]), I see compilation errors in C++ mode:
/home/bruno/msvc/compile cl -nologo -DHAVE_CONFIG_H -DEXEEXT=\".exe\" -DEXEEXT=\".exe\" -I. -I../../gltests -I.. -DGNULIB_STRICT_CHECKING=1 -DIN_GNULIB_TESTS=1 -I. -I../../gltests -I.. -I../../gltests/.. -I../gllib -I../../gltests/../gllib -D_WIN32_WINNT=_WIN32_WINNT_WIN7 -I/usr/local/msvc64/include -MD -c -o test-assert-h-c++.obj `cygpath -w '../../gltests/test-assert-h-c++.cc'` test-assert-h-c++.cc C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.35.32215\include\iterator(248): error C2059: syntax error: 'string' ... The cause is that the C++ library code has static_assert invocations with arguments that contain commas (template instantiations), and these only work if static_assert is a compiler built-in, not a macro. So, Gnulib must not define static_assert as a macro on this platform. Fortunately the need for this macro definition is gone, as MSVC 14.30's static_assert supports both the 2-arguments form as well as the newer 1-argument form. [2] [1] https://en.wikipedia.org/wiki/Microsoft_Visual_C%2B%2B [2] https://learn.microsoft.com/en-us/cpp/cpp/static-assert?view=msvc-170 This patch thus fixes it. 2023-04-20 Bruno Haible <br...@clisp.org> assert-h, verify: Fix compilation error in C++ mode with MSVC 14.30. * lib/verify.h (_Static_assert): In C++ mode with MSVC 14.1 or newer, define merely to static_assert. (static_assert): In C++ mode with MSVC 14.1 or newer, don't define. diff --git a/lib/verify.h b/lib/verify.h index c700243209..e4af91517e 100644 --- a/lib/verify.h +++ b/lib/verify.h @@ -241,10 +241,16 @@ template <int w> # define _Static_assert(...) \ _GL_VERIFY (__VA_ARGS__, "static assertion failed", -) # else - /* Work around MSVC preprocessor incompatibility with ISO C; see - <https://stackoverflow.com/questions/5134523/>. */ -# define _Static_assert(R, ...) \ - _GL_VERIFY ((R), "static assertion failed", -) +# if defined __cplusplus && _MSC_VER >= 1910 + /* In MSVC 14.1 or newer, static_assert accepts one or two arguments, + but _Static_assert is not defined. */ +# define _Static_assert static_assert +# else + /* Work around MSVC preprocessor incompatibility with ISO C; see + <https://stackoverflow.com/questions/5134523/>. */ +# define _Static_assert(R, ...) \ + _GL_VERIFY ((R), "static assertion failed", -) +# endif # endif # endif /* Define static_assert if needed. */ @@ -252,7 +258,7 @@ template <int w> && __STDC_VERSION__ < 202311 \ && (!defined __cplusplus \ || (__cpp_static_assert < 201411 \ - && __GNUG__ < 6 && __clang_major__ < 6))) + && __GNUG__ < 6 && __clang_major__ < 6 && _MSC_VER < 1910))) # if defined __cplusplus && _MSC_VER >= 1900 && !defined __clang__ /* MSVC 14 in C++ mode supports the two-arguments static_assert but not the one-argument static_assert, and it does not support _Static_assert.
