Bug 1274334 - Enable STL wrappers on macos. r=firefox-build-system-reviewers,ahochheiden

Practically speaking, this doesn't make a huge difference, because
libmozglue contains operator new/operator delete overrides. This will
enable inlining opportunities, though.

It is worth noting that there's equivalent code in
js/src/old-configure.in but it's left as is because it is actually no-op
at the moment. This will be fixed in bug 1829049.

The check for __EXCEPTIONS is replaced with __cpp_exceptions because the
former is defined for any type of exception, including ObjC exceptions,
while the latter is defined for C++ exceptions only.

Differential Revision: https://phabricator.services.mozilla.com/D175976

config/gcc-stl-wrapper.template.h

@@ -8,9 +8,7 @@
 #ifndef mozilla_${HEADER}_h
 #define mozilla_${HEADER}_h
 
-// For some reason, Apple's GCC refuses to honor -fno-exceptions when
-// compiling ObjC.
-#if defined(__EXCEPTIONS) && __EXCEPTIONS && !(__OBJC__ && __GNUC__ && XP_IOS)
+#if defined(__cpp_exceptions) && __cpp_exceptions
 #  error "STL code can only be used with -fno-exceptions"
 #endif
 

old-configure.in

@@ -125,9 +125,6 @@ case "$target" in
           fi
           WIN32_REDIST_DIR=`cd "$WIN32_REDIST_DIR" && (pwd -W 2>/dev/null || pwd)`
         fi
-
-        WRAP_STL_INCLUDES=1
-        STL_FLAGS="-I${DIST}/stl_wrappers"
     else
         # Check w32api version
         _W32API_MAJOR_VERSION=`echo $W32API_VERSION | $AWK -F\. '{ print $1 }'`
@@ -603,14 +600,8 @@ MOZ_CXX11
 
 AC_LANG_C
 
-case "${OS_TARGET}" in
-Darwin)
-  ;;
-*)
-  STL_FLAGS="-I${DIST}/stl_wrappers"
-  WRAP_STL_INCLUDES=1
-  ;;
-esac
+STL_FLAGS="-I${DIST}/stl_wrappers"
+WRAP_STL_INCLUDES=1
 
 if test "$MOZ_BUILD_APP" = "tools/crashreporter/injector"; then
     WRAP_STL_INCLUDES=