Re: Avoid compiler warnings

[Ralf Wildenhues]

Hello Eric,

* Eric Blake wrote on Fri, Aug 11, 2006 at 06:42:47PM CEST:
> I tried configuring m4 with its --enable-debug switch, which enables various 
> -W 
> warning options, and combined it with -Werror to forcefully see the warnings. 
>  

Nice to have would be the exact list of warnings this enabled on your
system, the system, and the GCC version you used.  Plus the config.log
excerpts for the errors you encountered.  (This isn't necessary.)

> The compilation choked when compiling libltdl.  The check for AC_C_CONST is 
> now 
> obsolete, but warned due to -Wshadow, which made it fail and define const to 
> the empty string, and led to all sorts of followon fun.  And the check for 
> how 
> to use nm was failing due to -Wmissing-prototypes.  Yes, it's probably too 
> strict of an environment to sanely compile in normally, but it was easy 
> enough 
> to patch.  OK to apply?  Should I try backporting it to 1.5.x as well?

The changes in the first patch are ok provided they have been tested on
MinGW and Cygwin (MinGW exercises lt__dirent.h, right?); please do not
backport them to branch-1-5, though.  

* Eric Blake wrote on Fri, Aug 11, 2006 at 08:04:51PM CEST:
>
> A followon - using LTDL_SET_PRELOADED_SYMBOLS() choked with
> -Wnested-externs.
>
> 2006-08-11  Eric Blake  <address@hidden>
>
>       * libltdl/ltdl.h (lt_preloaded_symbols): Declare outside of a
>       nested scope.

No, please drop this patch.  (Rationale: I'm not convinced this
declaration isn't a problem on some w32 system.)

Cheers,
Ralf