tools: teach gyp to write an 'all deps' rule

Make GYP write a .deps file in the top-level directory that we can use
in the Makefile to get a proper dependency chain for the `node` target.
Preparatory work for getting rid of recursive make invocations.

PR-URL: nodejs#17407
Reviewed-By: Richard Lau <[email protected]>

tools/gyp/pylib/gyp/generator/make.py

@@ -2136,6 +2136,7 @@ def CalculateMakefilePath(build_file, base_name):
     for target in gyp.common.AllTargets(target_list, target_dicts, build_file):
       needed_targets.add(target)
 
+  all_deps = set()
   build_files = set()
   include_list = set()
   for qualified_target in target_list:
@@ -2184,6 +2185,12 @@ def CalculateMakefilePath(build_file, base_name):
                                               os.path.dirname(makefile_path))
     include_list.add(mkfile_rel_path)
 
+    if 'actions' in spec:
+      for action in spec['actions']:
+        all_deps.update(map(writer.Absolutify, action['inputs']))
+    if 'sources' in spec:
+      all_deps.update(map(writer.Absolutify, spec['sources']))
+
   # Write out per-gyp (sub-project) Makefiles.
   depth_rel_path = gyp.common.RelativePath(options.depth, os.getcwd())
   for build_file in build_files:
@@ -2227,3 +2234,10 @@ def CalculateMakefilePath(build_file, base_name):
   root_makefile.write(SHARED_FOOTER)
 
   root_makefile.close()
+
+  # Hack to get rid of $(obj)/path/to/foo.o deps that node.gyp adds manually.
+  all_deps = [s for s in all_deps if not '$' in s]
+  all_deps_path = os.path.join(options.toplevel_dir, '.deps')
+  with open(all_deps_path, 'w') as f:
+    f.write('ALL_DEPS := \\\n\t')
+    f.write(' \\\n\t'.join(sorted(all_deps)))