[PATCH] Use a configure test to detect the form of malloc_usable_size in malloc.h

[Mike Hommey]

On Wed, May 21, 2014 at 10:37:26PM +0900, Mike Hommey wrote:
> From: Mike Hommey <mh at glandium.org>
> 
> ---
>  configure.ac | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index 57015d1..0a3d8a8 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -258,7 +258,6 @@ dnl Define cpp macros in CPPFLAGS, rather than doing AC_DEFINE(macro), since the
>  dnl definitions need to be seen before any headers are included, which is a pain
>  dnl to make happen otherwise.
>  default_munmap="1"
> -JEMALLOC_USABLE_SIZE_CONST="const"
>  case "${host}" in
>    *-*-darwin*)
>  	CFLAGS="$CFLAGS"
> @@ -286,7 +285,6 @@ case "${host}" in
>  	AC_DEFINE([JEMALLOC_HAS_ALLOCA_H])
>  	AC_DEFINE([JEMALLOC_PURGE_MADVISE_DONTNEED], [ ])
>  	AC_DEFINE([JEMALLOC_THREADED_INIT], [ ])
> -	JEMALLOC_USABLE_SIZE_CONST=""
>  	default_munmap="0"
>  	;;
>    *-*-netbsd*)
> @@ -351,6 +349,22 @@ case "${host}" in
>  	abi="elf"
>  	;;
>  esac
> +
> +JEMALLOC_USABLE_SIZE_CONST=
> +AC_CHECK_HEADERS([malloc.h], [
> +  AC_MSG_CHECKING([whether system malloc_usable_size definition uses const argument])

Note, this sentence is wrong on windows, where there is no system
malloc_usable_size, but where the test *does* run and return yes.

Also, it might be better to check independently of whether malloc.h is
available or not.

Tell me if you want me to fix those.

Mike