weakref.m4: New file.

config:

	* weakref.m4: New file.

libitm:

	* configure.ac: Use GCC_CHECK_ELF_STYLE_WEAKREF.
	* alloc_cpp.cc: Generate dummy functions if we don't
	HAVE_ELF_STYLE_WEAKREF.
	* eh_cpp.cc: Likewise.
	* configure: Regenerate.
	* aclocal.m4:  Likewise.
	* config.h.in: Likewise.
	* Makefile.in: Likewise.
	* testsuite/Makefile.in: Likewise.

From-SVN: r181618

config/ChangeLog

+2011-11-22  Iain Sandoe  <iains@gcc.gnu.org>
+
+	* weakref.m4: New file.
+
 2011-11-09  Richard Henderson  <rth@redhat.com>
 
 	* asmcfi.m4: New file.

config/weakref.m4

+
+dnl Check if the target supports weak.
+AC_DEFUN([GCC_CHECK_ATTRIBUTE_WEAK], [
+  AC_CACHE_CHECK([whether the target supports weak],
+		 ac_cv_have_attribute_weak, [
+  weakref_m4_saved_CFLAGS="$CFLAGS"
+  CFLAGS="$CFLAGS -Werror"
+  AC_TRY_COMPILE([void __attribute__((weak)) foo(void) { }],
+		 [], ac_cv_have_attribute_weak=yes,
+		 ac_cv_have_attribute_weak=no)
+  CFLAGS="$weakref_m4_saved_CFLAGS"])
+  if test x"$ac_cv_have_attribute_weak" = xyes; then
+    AC_DEFINE(HAVE_ATTRIBUTE_WEAK, 1,
+      [Define to 1 if the target supports __attribute__((weak)).])
+  fi])
+
+dnl Check whether weak refs work like the ELF ones.
+dnl This means that the weak reference works without having to satify 
+dnl linkage for the item.
+dnl There are targets (at least Darwin) where we have fully functional
+dnl weakrefs at runtime, but must supply the referenced item at link time.
+AC_DEFUN([GCC_CHECK_ELF_STYLE_WEAKREF], [
+  AC_CACHE_CHECK([whether weak refs work like ELF],
+                  ac_cv_have_elf_style_weakref, [
+  weakref_m4_saved_CFLAGS="$CFLAGS"
+  case "${host}" in
+    *-apple-darwin*) CFLAGS="$CFLAGS -Wl,-undefined,dynamic_lookup" ;;
+    *) ;;
+  esac  
+  AC_RUN_IFELSE([AC_LANG_SOURCE([[
+extern void fNotToBeFound(void) __attribute__((weak));
+int main () 
+{
+  if (fNotToBeFound)
+    return 1;
+  else
+    return 0;
+}
+]])], ac_cv_have_elf_style_weakref=yes, ac_cv_have_elf_style_weakref=no, [
+case "${host}" in
+  alpha*-dec-osf*) ac_cv_have_elf_style_weakref=no ;;
+  *-apple-darwin[[89]]*) ac_cv_have_elf_style_weakref=no ;;
+  *) ac_cv_have_elf_style_weakref=yes;;
+esac])CFLAGS="$weakref_m4_saved_CFLAGS"])
+if test x"$ac_cv_have_elf_style_weakref" = xyes; then
+  AC_DEFINE(HAVE_ELF_STYLE_WEAKREF, 1, [Define to 1 if target has a weakref that works like the ELF one.])
+fi])
+

libitm/ChangeLog

 2011-11-22  Iain Sandoe  <iains@gcc.gnu.org>
 
+	* configure.ac: Use GCC_CHECK_ELF_STYLE_WEAKREF.
+	* alloc_cpp.cc: Generate dummy functions if we don't
+	HAVE_ELF_STYLE_WEAKREF.
+	* eh_cpp.cc: Likewise.
+	* configure: Regenerate.
+	* aclocal.m4:  Likewise.
+	* config.h.in: Likewise.
+	* Makefile.in: Likewise.
+	* testsuite/Makefile.in: Likewise.
+
+2011-11-22  Iain Sandoe  <iains@gcc.gnu.org>
+
 	* config/x86/sjlj.S (CONCAT1, CONCAT2, SYM): Respond to
 	__USER_LABEL_PREFIX__ for targets that use it.
-	TYPE, SIZE, HIDDEN): New macros to assist on non-elf targets.
+	(TYPE, SIZE, HIDDEN): New macros to assist on non-elf targets.
 	(_ITM_beginTransaction): Use SYM, TYPE, SIZE macros to assist
 	in portability to non-elf targets.
-	(GTM_longjmp): LIkewise.
+	(GTM_longjmp): Likewise.
 	* libitm_i.h (begin_transaction): Apply __USER_LABEL_PREFIX__
 	where required.
 

libitm/Makefile.in

@@ -57,10 +57,12 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/acx.m4 \
 	$(top_srcdir)/../config/multi.m4 \
 	$(top_srcdir)/../config/override.m4 \
 	$(top_srcdir)/../config/stdint.m4 \
-	$(top_srcdir)/../config/tls.m4 $(top_srcdir)/../ltoptions.m4 \
-	$(top_srcdir)/../ltsugar.m4 $(top_srcdir)/../ltversion.m4 \
-	$(top_srcdir)/../lt~obsolete.m4 $(top_srcdir)/acinclude.m4 \
-	$(top_srcdir)/../libtool.m4 $(top_srcdir)/configure.ac
+	$(top_srcdir)/../config/tls.m4 \
+	$(top_srcdir)/../config/weakref.m4 \
+	$(top_srcdir)/../ltoptions.m4 $(top_srcdir)/../ltsugar.m4 \
+	$(top_srcdir)/../ltversion.m4 $(top_srcdir)/../lt~obsolete.m4 \
+	$(top_srcdir)/acinclude.m4 $(top_srcdir)/../libtool.m4 \
+	$(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 am__CONFIG_DISTCLEAN_FILES = config.status config.cache config.log \

libitm/aclocal.m4

@@ -1001,6 +1001,7 @@ m4_include([../config/multi.m4])
 m4_include([../config/override.m4])
 m4_include([../config/stdint.m4])
 m4_include([../config/tls.m4])
+m4_include([../config/weakref.m4])
 m4_include([../ltoptions.m4])
 m4_include([../ltsugar.m4])
 m4_include([../ltversion.m4])

libitm/alloc_cpp.cc

@@ -60,7 +60,7 @@ extern void _ZdlPvRKSt9nothrow_t (void *, c_nothrow_p) __attribute__((weak));
 extern void *_ZnaXRKSt9nothrow_t (size_t, c_nothrow_p) __attribute__((weak));
 extern void _ZdaPvRKSt9nothrow_t (void *, c_nothrow_p) __attribute__((weak));
 
-#ifdef __osf__ /* Really: !HAVE_WEAKDEF  */
+#if !defined (HAVE_ELF_STYLE_WEAKREF)
 void *_ZnwX (size_t) { return NULL; }
 void _ZdlPv (void *) { return; }
 void *_ZnaX (size_t) { return NULL; }
@@ -70,7 +70,7 @@ void *_ZnwXRKSt9nothrow_t (size_t, c_nothrow_p) { return NULL; }
 void _ZdlPvRKSt9nothrow_t (void *, c_nothrow_p) { return; }
 void *_ZnaXRKSt9nothrow_t (size_t, c_nothrow_p) { return NULL; }
 void _ZdaPvRKSt9nothrow_t (void *, c_nothrow_p) { return; }
-#endif /* __osf__ */
+#endif /* HAVE_ELF_STYLE_WEAKREF */
 
 /* Wrap the delete nothrow symbols for usage with a single argument.
    Perhaps should have a configure type check for this, because the

libitm/config.h.in

@@ -30,6 +30,9 @@
 /* Define to 1 if you have the <dlfcn.h> header file. */
 #undef HAVE_DLFCN_H
 
+/* Define to 1 if target has a weakref that works like the ELF one. */
+#undef HAVE_ELF_STYLE_WEAKREF
+
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
 

libitm/configure

@@ -17213,6 +17213,57 @@ $as_echo "#define HAVE_AS_AVX 1" >>confdefs.h
   ;;
 esac
 
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether weak refs work like ELF" >&5
+$as_echo_n "checking whether weak refs work like ELF... " >&6; }
+if test "${ac_cv_have_elf_style_weakref+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  weakref_m4_saved_CFLAGS="$CFLAGS"
+  case "${host}" in
+    *-apple-darwin*) CFLAGS="$CFLAGS -Wl,-undefined,dynamic_lookup" ;;
+    *) ;;
+  esac
+  if test "$cross_compiling" = yes; then :
+
+case "${host}" in
+  alpha*-dec-osf*) ac_cv_have_elf_style_weakref=no ;;
+  *-apple-darwin[89]*) ac_cv_have_elf_style_weakref=no ;;
+  *) ac_cv_have_elf_style_weakref=yes;;
+esac
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+extern void fNotToBeFound(void) __attribute__((weak));
+int main ()
+{
+  if (fNotToBeFound)
+    return 1;
+  else
+    return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  ac_cv_have_elf_style_weakref=yes
+else
+  ac_cv_have_elf_style_weakref=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+CFLAGS="$weakref_m4_saved_CFLAGS"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_have_elf_style_weakref" >&5
+$as_echo "$ac_cv_have_elf_style_weakref" >&6; }
+if test x"$ac_cv_have_elf_style_weakref" = xyes; then
+
+$as_echo "#define HAVE_ELF_STYLE_WEAKREF 1" >>confdefs.h
+
+fi
+
 # Cleanup and exit.
 CFLAGS="$save_CFLAGS"
 cat >confcache <<\_ACEOF

libitm/configure.ac

@@ -239,6 +239,8 @@ LIBITM_CHECK_SYNC_BUILTINS
 LIBITM_CHECK_64BIT_SYNC_BUILTINS
 LIBITM_CHECK_AS_AVX
 
+GCC_CHECK_ELF_STYLE_WEAKREF
+
 # Cleanup and exit.
 CFLAGS="$save_CFLAGS"
 AC_CACHE_SAVE

libitm/eh_cpp.cc

@@ -39,13 +39,13 @@ extern void *__cxa_begin_catch (void *) WEAK;
 extern void *__cxa_end_catch (void) WEAK;
 extern void __cxa_tm_cleanup (void *, void *, unsigned int) WEAK;
 
-#ifdef __osf__ /* Really: !HAVE_WEAKDEF  */
+#if !defined (HAVE_ELF_STYLE_WEAKREF)
 void *__cxa_allocate_exception (size_t) { return NULL; }
 void __cxa_throw (void *, void *, void *) { return; }
 void *__cxa_begin_catch (void *) { return NULL; }
 void *__cxa_end_catch (void) { return NULL; }
 void __cxa_tm_cleanup (void *, void *, unsigned int) { return; }
-#endif
+#endif /* HAVE_ELF_STYLE_WEAKREF */
 
 }
 

libitm/testsuite/Makefile.in

@@ -47,10 +47,12 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/acx.m4 \
 	$(top_srcdir)/../config/multi.m4 \
 	$(top_srcdir)/../config/override.m4 \
 	$(top_srcdir)/../config/stdint.m4 \
-	$(top_srcdir)/../config/tls.m4 $(top_srcdir)/../ltoptions.m4 \
-	$(top_srcdir)/../ltsugar.m4 $(top_srcdir)/../ltversion.m4 \
-	$(top_srcdir)/../lt~obsolete.m4 $(top_srcdir)/acinclude.m4 \
-	$(top_srcdir)/../libtool.m4 $(top_srcdir)/configure.ac
+	$(top_srcdir)/../config/tls.m4 \
+	$(top_srcdir)/../config/weakref.m4 \
+	$(top_srcdir)/../ltoptions.m4 $(top_srcdir)/../ltsugar.m4 \
+	$(top_srcdir)/../ltversion.m4 $(top_srcdir)/../lt~obsolete.m4 \
+	$(top_srcdir)/acinclude.m4 $(top_srcdir)/../libtool.m4 \
+	$(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 mkinstalldirs = $(SHELL) $(top_srcdir)/../mkinstalldirs