Bug 1378592 - Remove MOZ_REPLACE_MALLOC_LINKAGE. r=froydnj

MOZ_REPLACE_MALLOC_LINKAGE was added back when there were problems with
getting weak references working properly for replace-malloc.

Versions of OSX < 10.6 needed flat namespace, but aren't supported
anymore.

Versions of Xcode < 4.5 required flat namespace + a dummy library in
order to produce proper weak references. There is virtually nobody still
building with such an ancient toolchain.

Keeping those around doesn't /really/ hurt, except recent versions of
Xcode don't expose dyldinfo in /usr/bin, used for the configure test.
Consequently, MOZ_REPLACE_MALLOC_LINKAGE ended up being set to use the
dummy library setup, which, by using flat namespace, now causes harm in
bug 1356701, causing bug 1378332.

--HG--
extra : rebase_source : e3edc1f2cf905943c33fafeb631f2f88fc87167e

config/recurse.mk

@@ -185,9 +185,6 @@ ifdef MOZ_LDAP_XPCOM
 ldap/target: security/target mozglue/build/target
 toolkit/library/target: ldap/target
 endif
-ifeq ($(MOZ_REPLACE_MALLOC_LINKAGE),dummy library)
-mozglue/build/target memory/replace/logalloc/replay/target: memory/replace/dummy/target
-endif
 endif
 # Most things are built during compile (target/host), but some things happen during export
 # Those need to depend on config/export for system wrappers.

memory/replace/moz.build

@@ -9,8 +9,5 @@ DIRS += [
     'replace',
 ]
 
-if CONFIG['MOZ_REPLACE_MALLOC_LINKAGE'] == 'dummy library':
-    DIRS += ['dummy']
-
 if CONFIG['MOZ_DMD']:
     DIRS += ['dmd']

mozglue/build/replace_malloc.mk

@@ -22,12 +22,5 @@ OS_LDFLAGS += \
   -Wl,-U,_replace_jemalloc_thread_local_arena \
   $(NULL)
 
-ifneq ($(MOZ_REPLACE_MALLOC_LINKAGE),compiler support)
-OS_LDFLAGS += -flat_namespace
-endif
-ifeq ($(MOZ_REPLACE_MALLOC_LINKAGE),dummy library)
-OS_LDFLAGS += -Wl,-weak_library,$(DEPTH)/memory/replace/dummy/$(DLL_PREFIX)dummy_replace_malloc$(DLL_SUFFIX)
-endif
-
 EXTRA_DEPS += $(topsrcdir)/mozglue/build/replace_malloc.mk
 endif

old-configure.in

@@ -4003,61 +4003,6 @@ Android|WINNT|Darwin)
   ;;
 esac
 
-if test -n "$MOZ_REPLACE_MALLOC"; then
-    dnl Replace-malloc Mac linkage quirks
-    if test -n "$MACOSX_DEPLOYMENT_TARGET"; then
-        AC_CACHE_CHECK([how to do weak dynamic linking],
-            ac_cv_weak_dynamic_linking,
-            [echo 'extern void foo() __attribute__((weak_import));int bar() { if (foo) foo(); return 0; }' > conftest.c
-             if AC_TRY_COMMAND([${CC-cc} -o conftest${DLL_SUFFIX} $CFLAGS -dynamiclib $LDFLAGS -Wl,-U,_foo conftest.c $LIBS 1>&5]) &&
-                test -s conftest${DLL_SUFFIX}; then
-                 dnl There are several ways the linker can put link edit rules in a binary:
-                 dnl - classic info only (for OSX < 10.6)
-                 dnl - dyld info only
-                 dnl - both
-                 if "$OTOOL" -l conftest${DLL_SUFFIX} 2> /dev/null | grep "LC_DYLD_INFO_ONLY" > /dev/null; then
-                     _CLASSIC_INFO=
-                 else
-                     _CLASSIC_INFO=1
-                 fi
-                 if "$OTOOL" -l conftest${DLL_SUFFIX} 2> /dev/null | grep "LC_DYLD_INFO" > /dev/null; then
-                     _DYLD_INFO=1
-                 else
-                     _DYLD_INFO=
-                 fi
-                 dnl With classic info, we need to build with -flat_namespace.
-                 dnl With dyld info, Xcode 4.5 does the right thing without additional flags,
-                 dnl but Xcode < 4.5 requires a dummy library and -flat_namespace because it
-                 dnl forgets to set the weak flag in the dyld info.
-                 dnl See http://glandium.org/blog/?p=2764 for more details.
-                 dnl
-                 dnl Values for ac_cv_weak_dynamic_linking, and subsequently
-                 dnl MOZ_REPLACE_MALLOC_LINKAGE are thus:
-                 dnl - "flat namespace" when -flat_namespace alone is needed
-                 dnl - "dummy library" when a dummy library and -flat_namespace are needed
-                 dnl - "compiler support" when nothing is needed
-                 if test -n "$_DYLD_INFO" && ${TOOLCHAIN_PREFIX}dyldinfo -bind conftest${DLL_SUFFIX} 2> /dev/null | grep "_foo (weak import)" > /dev/null; then
-                     if test -n "$_CLASSIC_INFO"; then
-                         ac_cv_weak_dynamic_linking="flat namespace"
-                     else
-                         ac_cv_weak_dynamic_linking="compiler support"
-                     fi
-                 else
-                     if test -n "$_DYLD_INFO"; then
-                         ac_cv_weak_dynamic_linking="dummy library"
-                     else
-                         ac_cv_weak_dynamic_linking="flat namespace"
-                     fi
-                 fi
-             else
-                 AC_ERROR([couldn't compile a simple C file])
-             fi
-             rm -rf conftest*])
-        MOZ_REPLACE_MALLOC_LINKAGE="$ac_cv_weak_dynamic_linking"
-    fi
-fi
-AC_SUBST(MOZ_REPLACE_MALLOC_LINKAGE)
-
 dnl ========================================================
 dnl = Jemalloc build setup
 dnl ========================================================