@@ -5589,6 +5589,21 @@ check_cxxflags_cc -std=$stdcxx ctype.h "__cplusplus >= 201103L" ||
check_cflags_cc -std=$stdc ctype.h "__STDC_VERSION__ >= 201112L" ||
{ check_cflags_cc -std=c11 ctype.h "__STDC_VERSION__ >= 201112L" && stdc="c11" || die "Compiler lacks C11 support"; }
+for static_assert in "" _Static_assert; do
+ test_cc ${static_assert:+-Dstatic_assert=$static_assert} <<EOF && { test -z "$static_assert" || add_cppflags "-Dstatic_assert=$static_assert"; } && break
+#include <assert.h>
+#include <stddef.h>
+struct Foo {
+ int a;
+ void *ptr;
+} obj;
+static_assert(offsetof(struct Foo, a) == 0,
+ "First element of struct does not have offset 0");
+static_assert(offsetof(struct Foo, ptr) >= offsetof(struct Foo, a) + sizeof(obj.a),
+ "elements not properly ordered in struct");
+EOF
+done || die "Compiler lacks support for C11 static_assert"
+
check_cppflags -D_FILE_OFFSET_BITS=64
check_cppflags -D_LARGEFILE_SOURCE
C11 provides static assertions via _Static_assert and provides static_assert as a convenience define for this in assert.h. MSVC 19.27 declares support C11, but does not support _Static_assert, but somehow supports static_assert. That's therefore what we use. But apparently there are some old GCC toolchains where _Static_assert is supported, but assert.h does not provide the fallback define. Some fate boxes are affected by this [1]. This commit therefore checks whether static_assert works with assert.h included; if not, it checks whether using -Dstatic_assert=_Static_assert fixes it. Otherwise it errors out. [1]: https://fate.ffmpeg.org/report.cgi?time=20240321123620&slot=sh4-debian-qemu-gcc-4.7 Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> --- configure | 15 +++++++++++++++ 1 file changed, 15 insertions(+)