Bug 1368035 - Enable geckodriver building in automation; r=ted

geckodriver compilation was disabled by default in
https://bugzilla.mozilla.org/show_bug.cgi?id=1368084 due to issues
building it locally on Windows.

This re-enables building of geckodriver in automation, but gives
developers an option, --enable-geckodriver, to opt-in to building
it locally.

geckodriver is implied on supported platforms when MOZ_AUTOMATION is
set, but we also provide the option for developers to use.  This means
geckodriver will be built in CI by default, but not in developers'
local environments.

MozReview-Commit-ID: ACkO97ekVsi

--HG--
extra : rebase_source : 067e25911f72d80a54e662f24cc71dedde53a4e1

build/moz.configure/toolchain.configure

@@ -140,9 +140,6 @@ def sccache_verbose_stats(using_sccache, verbose_stats):
 
 set_config('SCCACHE_VERBOSE_STATS', sccache_verbose_stats)
 
-option(env='MOZ_HAZARD', help='Build for the GC rooting hazard analysis')
-set_config('MOZ_HAZARD', depends_if('MOZ_HAZARD')(lambda _: True))
-
 @depends('--with-compiler-wrapper', ccache)
 @imports(_from='mozbuild.shellutil', _import='split', _as='shell_split')
 def compiler_wrapper(wrapper, ccache):
@@ -172,6 +169,18 @@ def using_compiler_wrapper(compiler_wrapper):
 set_config('MOZ_USING_COMPILER_WRAPPER', using_compiler_wrapper)
 
 
+# GC rooting and hazard analysis.
+# ==============================================================
+option(env='MOZ_HAZARD', help='Build for the GC rooting hazard analysis')
+
+@depends('MOZ_HAZARD')
+def hazard_analysis(value):
+    if value:
+        return True
+
+set_config('MOZ_HAZARD', hazard_analysis)
+
+
 # Cross-compilation related things.
 # ==============================================================
 js_option('--with-toolchain-prefix', env='TOOLCHAIN_PREFIX', nargs=1,

toolkit/moz.configure

@@ -1090,3 +1090,35 @@ def marionette(value):
         return True
 
 set_config('ENABLE_MARIONETTE', marionette)
+
+# geckodriver WebDriver implementation
+# ==============================================================
+option('--enable-geckodriver', help='Enable WebDriver implementation')
+
+@depends('--enable-geckodriver',
+         'MOZ_AUTOMATION',
+         compile_environment,
+         cross_compiling,
+         hazard_analysis,
+         target)
+def geckodriver(enable, automation, compile_env, cross_compile, hazard, target):
+    """
+    geckodriver is implied on supported platforms when MOZ_AUTOMATION
+    is set, but we also provide the --enable-geckodriver option for
+    developers to use.
+
+    At the present time, we want individual developers to be able to
+    opt-in to building geckodriver locally, and for it to be enabled by
+    default on supported CI build platforms.
+    """
+    if enable:
+        return True
+
+    if enable.origin == 'default':
+        linux32 = target.kernel == 'Linux' and target.cpu == 'x86'
+        broken_platforms = cross_compile or linux32 or hazard
+
+        if automation and compile_env and not broken_platforms:
+            return True
+
+set_config('ENABLE_GECKODRIVER', geckodriver)

toolkit/toolkit.mozbuild

@@ -154,27 +154,8 @@ if CONFIG['ENABLE_MARIONETTE']:
         '/testing/marionette',
     ]
 
-    """
-    Temporarily disable building ../testing/geckodriver
-    until https://bugzilla.mozilla.org/show_bug.cgi?id=1368035,
-    letting local developer builds opt in with --enable-geckodriver is fixed.
-
-    # Disable building of geckodriver for artifact builds and in
-    # environments where cross compiling occurs (macOS and Android),
-    # on hazard builds, and on Linux x86 (linking problems).
-    #
-    # https://bugzilla.mozilla.org/show_bug.cgi?id=1341041
-    # https://bugzilla.mozilla.org/show_bug.cgi?id=1329737
-    # https://bugzilla.mozilla.org/show_bug.cgi?id=1367519
-    # https://bugzilla.mozilla.org/show_bug.cgi?id=1367736
-    if (not CONFIG['COMPILE_ENVIRONMENT'] or
-            CONFIG['CROSS_COMPILE'] or
-            (CONFIG['OS_TARGET'] == 'Linux' and CONFIG['TARGET_CPU'] == 'i686') or
-            CONFIG['MOZ_HAZARD']):
-        pass
-    else:
-        DIRS += ['/testing/geckodriver']
-    """
+if CONFIG['ENABLE_GECKODRIVER']:
+    DIRS += ['/testing/geckodriver']
 
 DIRS += [
     '/tools/quitter',