include/stdlib.h: only expose reallocarray() prototype when implementation is available
The reallocarray() primitive is only provided by the malloc-standard
implementation: neither malloc nor malloc-simple provide it. This
causes issues when building for example util-linux on noMMU platforms
as:
- noMMU platforms can't use malloc-standard, so either malloc or
malloc-simple are used, which means reallocarray() is not
implemented
- util-linux detects the absence of reallocarray(), and provides its
own implementation, but the prototype clashes with the prototype in
uClibc's <stdlib.h>
The combination of which causes the following build failure:
In file included from lib/color-names.c:7:
./include/c.h:586:21: error: static declaration of ‘reallocarray’ follows non-static declaration
586 | static inline void *reallocarray(void *ptr, size_t nmemb, size_t size)
| ^~~~~~~~~~~~
In file included from ./include/c.h:16:
/home/thomas/projets/buildroot/output/host/arm-buildroot-uclinux-uclibcgnueabi/sysroot/usr/include/stdlib.h:898:14: note: previous declaration of ‘reallocarray’ with type ‘void *(void *, size_t, size_t)’ {aka ‘void *(void *, unsigned int, unsigned int)’}
898 | extern void *reallocarray (void *__ptr, size_t __m, size_t __n);
| ^~~~~~~~~~~~
make[3]: *** [Makefile:12354: lib/libtcolors_la-color-names.lo] Error 1
To fix this, let's not expose the prototype of reallocarray() if we
don't provide the implementation for it.
Upstream: https://mailman.openadk.org/mailman3/hyperkitty/list/devel@uclibc-ng.org/thread/BX4ENNZYO23YQJQF5XITW7TETSJHEFK5/
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Thomas Petazzoni