[vlc-devel] [PATCH 0/2] Alternative mingw32 patchset

[Rémi Denis-Courmont]

Le 2015-03-16 12:53, Diego Elio Pettenò a écrit :
> On 16 March 2015 at 08:06, Rémi Denis-Courmont <remi at remlab.net> 
> wrote:
>> You have not described any situation where AC_CHECK_DECL would fail. 
>> I know
>> one case where AC_CHECK_DECL and the custom compile test will lead 
>> to
>> different configure results. That is if the identifier is defined 
>> with a
>> different prototype. But in this case, the compilation will fail 
>> either way
>> (and the SDK is unarguably broken).
>
> Symbol aliases and other non-standard linkage declarations, as well
> as macros.

Literally AC_CHECK_DECL checks if the symbol is defined in the 
preprocessor and/or the symbol is a r-value. In all of the relevant 
subset of cases above, it will pass.

Of course, if the symbol is defined with a different prototype, 
AC_CHECK_DECL will result in "yes", and compilation will fail. Custom 
code will result in "no" but compilation will fail too.

-- 
Rémi Denis-Courmont