Re: AC_PROG_CC_* shouldn't append multiple options

[Adrian Bunk]

On Thu, Sep 20, 2012 at 02:35:36PM -0700, Paul Eggert wrote:
> Thanks for mentiong that.  This area is a bit of a mess, so I took the
> liberty of addressing that issue by doing one of the things on the TODO
> list, and pushed the following patch into the autoconf master.  Please
> let me know if you have problems.
>...

First of all, thanks for your quick answer.

Unfortunately, I am having two problems with what you pushed:

ac_cv_prog_cc_c11 is no longer documented (but still set, and should
not be removed). Wanting to check that variable might even be a valid 
usecase for AC_PROG_CC_C11?

autoconf now sets the compiler to the last C mode requested, not the 
highest requested.
  AC_PROG_CC
  AC_PROG_CC_C99
results in a compiler in C99 mode for the build.

Even worse, some autoconf tests might run in in a higher mode than the
actual build (anything between the AC_PROG_CC and AC_PROG_CC_C99 will
run in C11 mode).

This is a real problem, since the usage of AC_PROG_CC_C99 in a macro 
like in AX_C99_INLINE [1] looks like a valid usecase to me.

cu
Adrian

[1] 
http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob_plain;f=m4/ax_c99_inline.m4

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