Re: vasnprintf.c shadowing warnings cause "make distcheck" failure

[Bruno Haible]

Jim Meyering wrote:
> vasnprintf.c uses variables named exp and remainder, and they shadow
> math functions.  This poses a problem for me, since coreutils' "make
> distcheck" requires a clean build with -Werror -Wshadow.

Ouch. It's a pity that "gcc -Wshadow" has a useful part (when it warns about
two variables inside a single function) and a useless part (when the outer
identifier comes from a global declaration in an include file), and gcc
does not offer to get the useful part alone.

> Bruno, any objection to this change?

The added lines come too early (in line 88, but <math.h> is included in
line 144). It lacks comments. And the identifiers that you chose will
not be available by tab-completion to the developer whose debugs in gdb.
I'm applying this instead:


2008-05-16  Jim Meyering  <address@hidden>
            Bruno Haible  <address@hidden>

        Avoid some warnings from "gcc -Wshadow".
        * lib/vasnprintf.c (exp, remainder): Define to different identifiers.

*** lib/vasnprintf.c.orig       2008-05-17 02:33:17.000000000 +0200
--- lib/vasnprintf.c    2008-05-17 02:32:13.000000000 +0200
***************
*** 200,205 ****
--- 200,212 ----
  /* Here we need to call the native sprintf, not rpl_sprintf.  */
  #undef sprintf
  
+ /* Avoid some warnings from "gcc -Wshadow".
+    This file doesn't use the exp() and remainder() functions.  */
+ #undef exp
+ #define exp expo
+ #undef remainder
+ #define remainder rem
+ 
  #if (NEED_PRINTF_DIRECTIVE_A || NEED_PRINTF_LONG_DOUBLE || NEED_PRINTF_DOUBLE 
|| NEED_PRINTF_INFINITE_DOUBLE) && !defined IN_LIBINTL
  /* Determine the decimal-point character according to the current locale.  */
  # ifndef decimal_point_char_defined