configure: enable additional code cleanliness warnings

We are supposed to handle compiling on a "C90 plus long long"
compiler, so make gcc (our most common development platform compiler)
complain when we don't.

However, suppress the complaints about the Microsoft definitions of
the <inttypes.h> strings.

From master branch checkin 25da6eaf43,
except that -Wwrite-strings is omitted; making the code base
-Wwrite-strings clean is going to take additional work.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

aclocal.m4

@@ -9,7 +9,8 @@ AC_DEFUN(PA_ADD_CFLAGS,
  CFLAGS="$CFLAGS $1"
  AC_TRY_LINK([#include <stdio.h>],
  [printf("Hello, World!\n");],
- AC_MSG_RESULT([yes]),
+ AC_MSG_RESULT([yes])
+ CFLAGS="$pa_add_cflags__old_cflags ifelse([$2],[],[$1],[$2])",
  AC_MSG_RESULT([no])
  CFLAGS="$pa_add_cflags__old_cflags")])
 

configure.in

@@ -183,6 +183,10 @@ AC_ARG_ENABLE([ccache],
 [])
 
 PA_ADD_CFLAGS([-pedantic])
+dnl Suppress format warning on Windows targets due to their <inttypes.h>
+PA_ADD_CFLAGS([-Wpedantic-ms-format],[-Wno-pedantic-ms-format])
+PA_ADD_CFLAGS([-Wc90-c99-compat])
+PA_ADD_CFLAGS([-Wlong-long],[-Wno-long-long])
 AC_ARG_ENABLE([werror],
 [AC_HELP_STRING([--enable-werror],
 [compile with -Werror to error out on any warning])],