Bug 1417264 - Write .mozconfig.mk file from Python; r=nalexander

The file is a filtered version of the make file that we previously
started generating for client.mk. Why there is special casing for
UPLOAD_EXTRA_FILES, I'm not sure. This smells fishy and is something
I'd like to take a look at once all code is ported out of client.mk.

The removal of the logic from client.mk meant that we could remove
a bunch of code from client.mk related to loading mozconfig files.
We can now simply include the auto-generated make file directly and
be done with it.

MozReview-Commit-ID: 4M5NElQA7iR

client.mk

@@ -37,27 +37,8 @@ PYTHON ?= $(shell which python2.7 > /dev/null 2>&1 && echo python2.7 || echo pyt
 ####################################
 # Load mozconfig Options
 
-# See build pages, http://www.mozilla.org/build/ for how to set up mozconfig.
-
-define CR
-
-
-endef
-
-# As $(shell) doesn't preserve newlines, use sed to replace them with an
-# unlikely sequence (||), which is then replaced back to newlines by make
-# before evaluation. $(shell) replacing newlines with spaces, || is always
-# followed by a space (since sed doesn't remove newlines), except on the
-# last line, so replace both '|| ' and '||'.
-MOZCONFIG_CONTENT := $(subst ||,$(CR),$(subst || ,$(CR),$(shell cat $(OBJDIR)/.mozconfig-client-mk | sed 's/$$/||/')))
 include $(OBJDIR)/.mozconfig-client-mk
 
-# As '||' was used as a newline separator, it means it's not occurring in
-# lines themselves. It can thus safely be used to replaces normal spaces,
-# to then replace newlines with normal spaces. This allows to get a list
-# of mozconfig output lines.
-MOZCONFIG_OUT_LINES := $(subst $(CR), ,$(subst $(NULL) $(NULL),||,$(MOZCONFIG_CONTENT)))
-
 ifdef MOZ_PARALLEL_BUILD
   MOZ_MAKE_FLAGS := $(filter-out -j%,$(MOZ_MAKE_FLAGS))
   MOZ_MAKE_FLAGS += -j$(MOZ_PARALLEL_BUILD)
@@ -92,16 +73,6 @@ $(error client.mk must be used via `mach`. Try running \
 `./mach $(firstword $(MAKECMDGOALS) $(.DEFAULT_GOAL))`)
 endif
 
-# For now, only output "export" lines and lines containing UPLOAD_EXTRA_FILES.
-MOZCONFIG_MK_LINES := $(filter export||% UPLOAD_EXTRA_FILES% %UPLOAD_EXTRA_FILES%,$(MOZCONFIG_OUT_LINES))
-$(OBJDIR)/.mozconfig.mk: $(TOPSRCDIR)/client.mk $(FOUND_MOZCONFIG)
-	$(if $(MOZCONFIG_MK_LINES),( $(foreach line,$(MOZCONFIG_MK_LINES), echo '$(subst ||, ,$(line))';) )) > $@
-
-# Include that makefile so that it is created. This should not actually change
-# the environment since MOZCONFIG_CONTENT, which MOZCONFIG_OUT_LINES derives
-# from, has already been eval'ed.
-include $(OBJDIR)/.mozconfig.mk
-
 # In automation, manage an sccache daemon. The starting of the server
 # needs to be in a make file so sccache inherits the jobserver.
 ifdef MOZBUILD_MANAGE_SCCACHE_DAEMON

python/mozbuild/mozbuild/controller/building.py

@@ -1353,11 +1353,24 @@ def _run_client_mk(self, target=None, line_handler=None, jobs=0,
                                         mozpath.normsep(mozconfig['path']))
             mozconfig_make_lines.append(b'export FOUND_MOZCONFIG')
 
+        # The .mozconfig.mk file only contains exported variables and lines with
+        # UPLOAD_EXTRA_FILES.
+        mozconfig_filtered_lines = [
+            line for line in mozconfig_make_lines
+            # Bug 1418122 investigate why UPLOAD_EXTRA_FILES is special and
+            # remove it.
+            if line.startswith(b'export ') or b'UPLOAD_EXTRA_FILES' in line
+        ]
+
         mozconfig_client_mk = os.path.join(self.topobjdir,
                                            '.mozconfig-client-mk')
         with FileAvoidWrite(mozconfig_client_mk) as fh:
             fh.write(b'\n'.join(mozconfig_make_lines))
 
+        mozconfig_mk = os.path.join(self.topobjdir, '.mozconfig.mk')
+        with FileAvoidWrite(mozconfig_mk) as fh:
+            fh.write(b'\n'.join(mozconfig_filtered_lines))
+
         if mozconfig_make_lines:
             self.log(logging.WARNING, 'mozconfig_content', {
                 'path': mozconfig['path'],