[PATCH 1/3] Replaced obsolete AC_TRY_COMPILE to AC_COMPILE_IFELSE

[Zack Weinberg]

On Tue, Feb 16, 2021 at 7:00 AM Naohiro Tamura <naohirot@fujitsu.com> wrote:
> This patch replaced obsolete AC_TRY_COMPILE to AC_COMPILE_IFELSE.
> It has been confirmed that GNU 'autoconf' 2.69 doesn't change any
> 'configure' files and suppressed obsolete warnings.

Thanks for doing this work.

> +AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[
>  #ifndef __CET__
>  # error no CET compiler support
> -#endif],
> +#endif]])],

This, and any other check where the code is entirely preprocessor
directives, should be changed to AC_PREPROC_IFELSE for efficiency.

> -AC_TRY_COMPILE([#include <float.h>], [
> +AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <float.h>[]], [[

Typo here: it should be

> +AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <float.h>]], [[

I believe this is the root cause of the problem Andreas pointed out.

I did not proofread the entire patch.

zw