Restore deprecation warnings, except for older libpng.

[bpt/emacs.git] / configure.in

diff --git a/configure.in b/configure.in
index 59a7130..4df1284 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -662,16 +662,19 @@ else
   nw="$nw -Wsign-conversion"        # Too many warnings for now
   nw="$nw -Woverlength-strings"     # Not a problem these days
   nw="$nw -Wtraditional-conversion" # Too many warnings for now
+  nw="$nw -Wunreachable-code"       # so buggy that it's now silently ignored
   nw="$nw -Wpadded"                 # Our structs are not padded
-  nw="$nw -Wredundant-decls"        # We regularly (re)declare getenv etc.
+  nw="$nw -Wredundant-decls"        # we regularly (re)declare functions
   nw="$nw -Wlogical-op"             # any use of fwrite provokes this
-  nw="$nw -Wformat-nonliteral"      # Emacs does this a lot
+  nw="$nw -Wformat-nonliteral"      # we do this a lot
   nw="$nw -Wvla"                    # warnings in gettext.h
   nw="$nw -Wnested-externs"         # use of XARGMATCH/verify_function__
   nw="$nw -Wswitch-enum"            # Too many warnings for now
   nw="$nw -Wswitch-default"         # Too many warnings for now
-  nw="$nw -Wfloat-equal"            # e.g., ftoastr.c
-  nw="$nw -Winline"                 # e.g., dispnew.c's inlining of row_equal_p
+  nw="$nw -Wfloat-equal"            # warns about high-quality code
+  nw="$nw -Winline"                 # OK to ignore 'inline'
+  nw="$nw -Wsync-nand"              # irrelevant here, and provokes ObjC warning
+  nw="$nw -Wunsafe-loop-optimizations" # OK to suppress unsafe optimizations
 
   # Emacs doesn't care about shadowing; see
   # <http://lists.gnu.org/archive/html/emacs-diffs/2011-11/msg00265.html>.
@@ -683,12 +686,6 @@ else
   nw="$nw -Wsuggest-attribute=const"
   nw="$nw -Wsuggest-attribute=pure"
 
-  # Some loops can't be optimized with -O1,
-  # so remove -Wunsafe-loop-optimizations.
-  if echo "$CFLAGS" | $EGREP 'O1' 1>/dev/null; then
-    nw="$nw -Wunsafe-loop-optimizations"
-  fi
-
   gl_MANYWARN_ALL_GCC([ws])
   gl_MANYWARN_COMPLEMENT([ws], [$ws], [$nw])
   for w in $ws; do
@@ -2453,7 +2450,7 @@ if test "${HAVE_X11}" = "yes"; then
   if test "${with_png}" != "no"; then
     # Debian unstable as of July 2003 has multiple libpngs, and puts png.h
     # in /usr/include/libpng.
-    AC_CHECK_HEADERS(png.h libpng/png.h)
+    AC_CHECK_HEADERS(png.h libpng/png.h, break)
     if test "$ac_cv_header_png_h" = yes || test "$ac_cv_header_libpng_png_h" = yes ; then
       AC_CHECK_LIB(png, png_get_channels, HAVE_PNG=yes, , -lz -lm)
     fi
@@ -2462,6 +2459,19 @@ if test "${HAVE_X11}" = "yes"; then
   if test "${HAVE_PNG}" = "yes"; then
     AC_DEFINE(HAVE_PNG, 1, [Define to 1 if you have the png library (-lpng).])
     LIBPNG="-lpng -lz -lm"
+
+    AC_CHECK_DECL(png_longjmp,
+      [],
+      [AC_DEFINE(PNG_DEPRECATED, [],
+        [Define to empty to suppress deprecation warnings when building
+         with --enable-gcc-warnings and with libpng versions before 1.5,
+         which lack png_longjmp.])],
+      [[#ifdef HAVE_LIBPNG_PNG_H
+       # include <libpng/png.h>
+       #else
+       # include <png.h>
+       #endif
+      ]])
   fi
 fi
 AC_SUBST(LIBPNG)