Bug 1780056: Set the deployment target for local macOS builds to 10.1…

…2 for all platforms and enable -Werror=unguarded-availability-new. r=glandium

Differential Revision: https://phabricator.services.mozilla.com/D153277

build/moz.configure/toolchain.configure

@@ -52,12 +52,19 @@ with only_when(target_is_osx):
         "--enable-macos-target",
         env="MACOSX_DEPLOYMENT_TARGET",
         nargs=1,
-        default=depends(target)(lambda t: "11.0" if t.cpu == "aarch64" else "10.12"),
+        default=depends(target, developer_options)
+            # We continue to target 10.12 on Intel, but can target 11.0 for
+            # aarch64 since the earliest hardware was released alongside 11.0.
+            # For local builds, we want to target 10.12 regardless of the
+            # underlying platform to catch any errors or warnings that wouldn't
+            # show up when targeting 11.0, since these would later show up on
+            # CI for Intel builds.
+            (lambda t, d: "11.0" if (t.cpu == "aarch64" and not d) else "10.12"),
         help="Set the minimum MacOS version needed at runtime{|}",
     )
 
-    @depends_if("--enable-macos-target")
-    def macos_target(value):
+    @depends_if("--enable-macos-target", developer_options)
+    def macos_target(value, _):
         return value[0]
 
 

build/moz.configure/warnings.configure

@@ -332,6 +332,9 @@ check_and_add_warning(
     ),
 )
 
+# Warn if APIs are used without available() checks on macOS.
+check_and_add_warning("-Werror=unguarded-availability-new", when=target_is_osx)
+
 # Please keep these last in this file
 add_old_configure_assignment("_WARNINGS_CFLAGS", warnings_flags.cflags)
 add_old_configure_assignment("_WARNINGS_CXXFLAGS", warnings_flags.cxxflags)