build: Force -fsigned-char on platforms where the default for char is unsigned

gcc on the ARM platform defaults 'char' to 'unsigned char' whereas Intel and
SPARC default to 'signed char'.  This is only an issue in the rare cases where
negative values are assigned to a 'char' but this this patch insures
compatibility by detecting platforms that default to 'unsigned' and adding an
'-fsigned-char' flag to _ASTCFLAGS.

If compiling for ARM (native or cross-compile) be sure to run ./bootstrap.sh
and ./configure to regenerate the build files.  You shouldn't have to do this
for Intel or SPARC.

Tested-by: George Joseph

Review: https://reviewboard.asterisk.org/r/4091/
........

Merged revisions 425964 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/13@425965 65c4cc65-6c06-0410-ace0-fbb531ad65f3

Makefile

@@ -104,7 +104,7 @@ export PYTHON
 
 # start the primary CFLAGS and LDFLAGS with any that were provided
 # to the configure script
-_ASTCFLAGS:=$(CONFIG_CFLAGS)
+_ASTCFLAGS:=$(CONFIG_CFLAGS) $(CONFIG_SIGNED_CHAR)
 _ASTLDFLAGS:=$(CONFIG_LDFLAGS)
 
 # Some build systems, such as the one in openwrt, like to pass custom target

configure.ac

@@ -192,6 +192,25 @@ esac
 AC_SUBST(OSARCH)
 AC_SUBST(PBX_WINARCH)
 
+AC_MSG_CHECKING(whether char is unsigned)
+AC_COMPILE_IFELSE(
+	[
+		AC_LANG_SOURCE(
+#include <limits.h>
+#if CHAR_MIN == 0
+#error
+#endif
+		)
+	],[
+		AC_MSG_RESULT(no)
+		CONFIG_SIGNED_CHAR=""
+	],[
+		AC_MSG_RESULT(yes)
+		CONFIG_SIGNED_CHAR="-fsigned-char"
+	]
+)
+AC_SUBST(CONFIG_SIGNED_CHAR)
+
 #  check for uname
 AC_PATH_TOOL([UNAME], [uname], No)
 if test ! x"${UNAME}" = xNo; then

include/asterisk/autoconfig.h.in

@@ -1289,6 +1289,11 @@
 /* Define to 1 if running on Darwin. */
 #undef _DARWIN_UNLIMITED_SELECT
 
+/* Enable large inode numbers on Mac OS X 10.5.  */
+#ifndef _DARWIN_USE_64_BIT_INODE
+# define _DARWIN_USE_64_BIT_INODE 1
+#endif
+
 /* Number of bits in a file offset, on hosts where this is settable. */
 #undef _FILE_OFFSET_BITS
 

makeopts.in

@@ -60,6 +60,7 @@ PTHREAD_LIBS=@PTHREAD_LIBS@
 
 CONFIG_CFLAGS=@CONFIG_CFLAGS@
 CONFIG_LDFLAGS=@CONFIG_LDFLAGS@
+CONFIG_SIGNED_CHAR=@CONFIG_SIGNED_CHAR@
 
 GNU_LD=@GNU_LD@
 WEAKREF=@PBX_WEAKREF@