dynarray: new module

* config/srclist.txt: Mention the new files.
* lib/cdefs.h (__attribute_maybe_unused__): New macro,
like Gnulib’s _GL_ATTRIBUTE_MAYBE_UNUSED but with glibc
naming conventions.
* lib/libc-config.h: Use it instead of __glibc_likely.
* lib/dynarray.h, modules/dynarray: New files.
* lib/malloc/dynarray-skeleton.c, lib/malloc/dynarray.h:
* lib/malloc/dynarray_at_failure.c:
* lib/malloc/dynarray_emplace_enlarge.c:
* lib/malloc/dynarray_finalize.c, lib/malloc/dynarray_resize.c:
* lib/malloc/dynarray_resize_clear.c, modules/dynarray:
New files, from glibc with the following changes needed for
portability to compilers that are not recent-enough GCC.
* lib/malloc/dynarray_at_failure.c: Include stdlib.h, for abort.
(__libc_dynarray_at_failure) [!_LIBC]: Simply abort.
* lib/malloc/dynarray_emplace_enlarge.c:
* lib/malloc/dynarray_resize.c:
Include intprops.h, and use INT_MULTIPLY_WRAPV instead
of __builtin_mul_overflow.
* lib/malloc/dynarray.h (__libc_dynarray_at_failure):
Use _Noreturn instead of __attribute__ ((noreturn)).
* lib/malloc/dynarray_resize_clear.c: Do not include stdlib.h;
it’s not needed.
(__libc_dynarray_resize_clear): Do not do arithmetic on void *.
* lib/malloc/dynarray-skeleton.c (struct DYNARRAY_STRUCT):
Do not use anonymous unions, as they are not in C99. All uses changed.
Use __nonnull (X) instead of __attribute__ ((nonnull X)),
and __attribute_maybe_unused__ instead of __attribute__ ((unused)).

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/cdefs.h b/lib/cdefs.h
index c4769aa70f..a22ae6db26 100644
--- a/lib/cdefs.h
+++ b/lib/cdefs.h
@@ -257,6 +257,14 @@
 # define __attribute_const__ /* Ignore */
 #endif
 
+#if defined __STDC_VERSION__ && 201710L < __STDC_VERSION__
+# define __attribute_maybe_unused__ [[__maybe_unused__]]
+#elif __GNUC_PREREQ (2,7) || __glibc_has_attribute (__unused__)
+# define __attribute_maybe_unused__ __attribute__ ((__unused__))
+#else
+# define __attribute_maybe_unused__ /* Ignore */
+#endif
+
 /* At some point during the gcc 3.1 development the `used' attribute
    for functions was introduced.  We don't want to use it unconditionally
    (although this would be possible) since it generates warnings.  */