[Freeciv-Dev] gcc's -Werror breaks configure process (PR#2104)

[Jason Short <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

When I use -Werror and some extra gcc warning flags, the result from 
running ./configure is quite different than when I don't.
With
  CFLAGS="" ./configure
I get config.h.normal.

With
  CFLAGS="-g -Werror -Wpointer-arith -Wcast-align -Wmissing-prototypes 
-Wmissing-declarations -O3" ./configure
I get config.h.werror.

Attached is a diff between the two.  Note that some important things, 
like sound library detection and inlining, break completely!
In most cases there is probably nothing FreeCiv can do to improve this 
situation.  In some cases we may be able to change local tests, or 
import new m4 macro files.
My system is Debian unstable.  No doubt this has direct bearing on 
*what* things fail.  However, it seems most likely that on any system 
*some* things would fail.
jason

--- config.h.normal     2002-10-02 23:59:47.000000000 -0500
+++ config.h.werror     2002-10-03 00:01:30.000000000 -0500
@@ -20,7 +20,7 @@
 #define ENABLE_NLS 1
 
 /* Esound support */
-#define ESD 1
+/* #undef ESD */
 
 /* Configuration autogenerated */
 #define FC_CONFIG_H 1
@@ -195,7 +195,7 @@
 #define HAVE_STRCASECMP 1
 
 /* Define to 1 if you have the `strchr' function. */
-#define HAVE_STRCHR 1
+/* #undef HAVE_STRCHR */
 
 /* Define to 1 if you have the `strcoll' function and it is properly defined.
    */
@@ -223,7 +223,7 @@
 #define HAVE_STRNCASECMP 1
 
 /* Define to 1 if you have the `strstr' function. */
-#define HAVE_STRSTR 1
+/* #undef HAVE_STRSTR */
 
 /* Define to 1 if you have the `strtoul' function. */
 #define HAVE_STRTOUL 1
@@ -287,7 +287,7 @@
 
 /* Define if you have a version of the 'vsnprintf' function that honours the
    size argument and has a proper return value. */
-#define HAVE_WORKING_VSNPRINTF 1
+/* #undef HAVE_WORKING_VSNPRINTF */
 
 /* Define to 1 if you have the `__argz_count' function. */
 #define HAVE___ARGZ_COUNT 1
@@ -344,10 +344,10 @@
 #define PATCH_VERSION 1
 
 /* Define as the return type of signal handlers (`int' or `void'). */
-#define RETSIGTYPE void
+#define RETSIGTYPE int
 
 /* SDL_Mixer support */
-#define SDL 1
+/* #undef SDL */
 
 /* Mingw32-specific setting - stdin */
 /* #undef SOCKET_ZERO_ISNT_STDIN */
@@ -367,7 +367,7 @@
 #define TIME_WITH_SYS_TIME 1
 
 /* Define to 1 if your <sys/time.h> declares `struct tm'. */
-/* #undef TM_IN_SYS_TIME */
+#define TM_IN_SYS_TIME 1
 
 /* Version number of package */
 #define VERSION "1.13.1-devel"
@@ -395,7 +395,7 @@
 
 /* Define as `__inline' if that's what the C compiler calls it, or to nothing
    if it is not supported. */
-/* #undef inline */
+#define inline 
 
 /* Define to `long' if <sys/types.h> does not define. */
 /* #undef off_t */