libchrome: downgrade mojom types at arc build time am: 7b91003f18android-11.0.0_r16android11-d1-b-release

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libchrome/+/11818324

Change-Id: Idecb28fc11fceb6d248bdf3f0ba4cc80fffc4451

3 files changed, 221 insertions, 10 deletions

diff --git a/Android.bp b/Android.bp
index e4f393412b..8104e8829b 100644
--- a/Android.bp
+++ b/Android.bp
@@ -779,14 +779,28 @@ genrule {
     out: ["common_custom_types__type_mappings"],
 }
 
+python_binary_host {
+    name: "mojom_types_downgrader",
+    main: "mojo/public/tools/bindings/mojom_types_downgrader.py",
+    srcs: [
+        "mojo/public/tools/bindings/mojom_types_downgrader.py",
+    ],
+    defaults: ["libmojo_scripts"],
+}
+
+generate_mojom_downgraded_files {
+    name: "libmojo_mojom_downgraded_files",
+    srcs: [":libmojo_mojom_files"],
+}
+
 generate_mojom_pickles {
     name: "libmojo_mojom_pickles",
-    srcs: [":libmojo_mojom_files"],
+    srcs: [":libmojo_mojom_downgraded_files"],
 }
 
 generate_mojom_headers {
     name: "libmojo_mojom_headers",
-    srcs: [":libmojo_mojom_files"],
+    srcs: [":libmojo_mojom_downgraded_files"],
     pickles: [":libmojo_mojom_pickles"],
     templates: ":libmojo_mojom_templates",
     flags: "--disallow_native_types",
@@ -795,7 +809,7 @@ generate_mojom_headers {
 
 generate_mojom_srcs {
     name: "libmojo_mojom_srcs",
-    srcs: [":libmojo_mojom_files"],
+    srcs: [":libmojo_mojom_downgraded_files"],
     pickles: [":libmojo_mojom_pickles"],
     templates: ":libmojo_mojom_templates",
     flags: "--disallow_native_types",
@@ -932,7 +946,7 @@ cc_library_shared {
 
 generate_mojom_srcjar {
     name: "libmojo_mojom_java_srcs",
-    srcs: [":libmojo_mojom_files"],
+    srcs: [":libmojo_mojom_downgraded_files"],
     pickles: [":libmojo_mojom_pickles"],
     srcjar: "libmojo_mojom.srcjar",
     templates: ":libmojo_mojom_templates",
diff --git a/mojo/public/tools/bindings/mojom_types_downgrader.py b/mojo/public/tools/bindings/mojom_types_downgrader.py
new file mode 100755
index 0000000000..15f0e3bac1
--- /dev/null
+++ b/mojo/public/tools/bindings/mojom_types_downgrader.py
@@ -0,0 +1,119 @@
+#!/usr/bin/env python
+# Copyright 2020 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""Downgrades *.mojom files to the old mojo types for remotes and receivers."""
+
+import argparse
+import fnmatch
+import os
+import re
+import shutil
+import sys
+import tempfile
+
+# List of patterns and replacements to match and use against the contents of a
+# mojo file. Each replacement string will be used with Python string's format()
+# function, so the '{}' substring is used to mark where the mojo type should go.
+_MOJO_REPLACEMENTS = {
+    r'pending_remote': r'{}',
+    r'pending_receiver': r'{}&',
+    r'pending_associated_remote': r'associated {}',
+    r'pending_associated_receiver': r'associated {}&',
+}
+
+# Pre-compiled regular expression that matches against any of the replacements.
+_REGEXP_PATTERN = re.compile(
+    r'|'.join(
+        ['{}\s*<\s*(.*?)\s*>'.format(k) for k in _MOJO_REPLACEMENTS.keys()]),
+    flags=re.DOTALL)
+
+
+def ReplaceFunction(match_object):
+  """Returns the right replacement for the string matched against the regexp."""
+  for index, (match, repl) in enumerate(_MOJO_REPLACEMENTS.items(), 1):
+    if match_object.group(0).startswith(match):
+      return repl.format(match_object.group(index))
+
+
+def DowngradeFile(path, output_dir=None):
+  """Downgrades the mojom file specified by |path| to the old mojo types.
+
+  Optionally pass |output_dir| to place the result under a separate output
+  directory, preserving the relative path to the file included in |path|.
+  """
+  # Use a temporary file to dump the new contents after replacing the patterns.
+  with open(path) as src_mojo_file:
+    with tempfile.NamedTemporaryFile(mode='w', delete=False) as tmp_mojo_file:
+      tmp_contents = _REGEXP_PATTERN.sub(ReplaceFunction, src_mojo_file.read())
+      tmp_mojo_file.write(tmp_contents)
+
+  # Files should be placed in the desired output directory
+  if output_dir:
+    output_filepath = os.path.join(output_dir, os.path.basename(path))
+    if not os.path.exists(output_dir):
+      os.makedirs(output_dir)
+  else:
+    output_filepath = path
+
+  # Write the new contents preserving the original file's attributes.
+  shutil.copystat(path, tmp_mojo_file.name)
+  shutil.move(tmp_mojo_file.name, output_filepath)
+
+  # Make sure to "touch" the new file so that access, modify and change times
+  # are always newer than the source file's, otherwise Modify time will be kept
+  # as per the call to shutil.copystat(), causing unnecessary generations of the
+  # output file in subsequent builds due to ninja considering it dirty.
+  os.utime(output_filepath, None)
+
+
+def DowngradeDirectory(path, output_dir=None):
+  """Downgrades mojom files inside directory |path| to the old mojo types.
+
+  Optionally pass |output_dir| to place the result under a separate output
+  directory, preserving the relative path to the file included in |path|.
+  """
+  # We don't have recursive glob.glob() nor pathlib.Path.rglob() in Python 2.7
+  mojom_filepaths = []
+  for dir_path, _, filenames in os.walk(path):
+    for filename in fnmatch.filter(filenames, "*mojom"):
+      mojom_filepaths.append(os.path.join(dir_path, filename))
+
+  for path in mojom_filepaths:
+    absolute_dirpath = os.path.dirname(os.path.abspath(path))
+    if output_dir:
+      dest_dirpath = output_dir + absolute_dirpath
+    else:
+      dest_dirpath = absolute_dirpath
+    DowngradeFile(path, dest_dirpath)
+
+
+def DowngradePath(src_path, output_dir=None):
+  """Downgrades the mojom files pointed by |src_path| to the old mojo types.
+
+  Optionally pass |output_dir| to place the result under a separate output
+  directory, preserving the relative path to the file included in |path|.
+  """
+  if os.path.isdir(src_path):
+    DowngradeDirectory(src_path, output_dir)
+  elif os.path.isfile(src_path):
+    DowngradeFile(src_path, output_dir)
+  else:
+    print(">>> {} not pointing to a valid file or directory".format(src_path))
+    sys.exit(1)
+
+
+def main():
+  parser = argparse.ArgumentParser(
+      description="Downgrade *.mojom files to use the old mojo types.")
+  parser.add_argument(
+      "srcpath", help="path to the file or directory to apply the conversion")
+  parser.add_argument(
+      "--outdir", help="the directory to place the converted file(s) under")
+  args = parser.parse_args()
+
+  DowngradePath(args.srcpath, args.outdir)
+
+
+if __name__ == "__main__":
+  sys.exit(main())
diff --git a/soong/bindings_generator.go b/soong/bindings_generator.go
index 2c5e3f672e..7ff98262ed 100644
--- a/soong/bindings_generator.go
+++ b/soong/bindings_generator.go
@@ -12,6 +12,7 @@ import (
 )
 
 func init() {
+	android.RegisterModuleType("generate_mojom_downgraded_files", mojomDowngradedFilesFactory)
 	android.RegisterModuleType("generate_mojom_pickles", mojomPicklesFactory)
 	android.RegisterModuleType("generate_mojom_headers", mojomHeadersFactory)
 	android.RegisterModuleType("generate_mojom_srcs", mojomSrcsFactory)
@@ -22,8 +23,19 @@ var (
 	pctx = android.NewPackageContext("android/soong/external/libchrome")
 
 	mojomBindingsGenerator = pctx.HostBinToolVariable("mojomBindingsGenerator", "mojom_bindings_generator")
+	mojomTypesDowngrader   = pctx.HostBinToolVariable("mojomTypesDowngrader", "mojom_types_downgrader")
 	mergeZips              = pctx.HostBinToolVariable("mergeZips", "merge_zips")
 
+	downgradeMojomTypesRule = pctx.StaticRule("downgradeMojomTypesRule", blueprint.RuleParams{
+		Command: `${mojomTypesDowngrader}
+		${in}
+		--outdir ${outDir}`,
+		CommandDeps: []string{
+			"${mojomTypesDowngrader}",
+		},
+		Description: "Downgrade mojom files $in => $out",
+	}, "outDir")
+
 	generateMojomPicklesRule = pctx.StaticRule("generateMojomPicklesRule", blueprint.RuleParams{
 		Command: `${mojomBindingsGenerator}
 		--use_bundled_pylibs parse
@@ -65,6 +77,72 @@ var (
 	})
 )
 
+type mojomDowngradedFilesProperties struct {
+	// list of input files
+	Srcs []string
+}
+
+type mojomDowngradedFiles struct {
+	android.ModuleBase
+
+	properties mojomDowngradedFilesProperties
+
+	generatedSrcs android.Paths
+	outDir        android.Path
+}
+
+var _ genrule.SourceFileGenerator = (*mojomDowngradedFiles)(nil)
+
+func (m *mojomDowngradedFiles) DepsMutator(ctx android.BottomUpMutatorContext) {
+	android.ExtractSourcesDeps(ctx, m.properties.Srcs)
+}
+
+func (m *mojomDowngradedFiles) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	m.outDir = android.PathForModuleGen(ctx, "")
+
+	for _, in := range ctx.ExpandSources(m.properties.Srcs, nil) {
+		if !strings.HasSuffix(in.Rel(), ".mojom") {
+			ctx.PropertyErrorf("srcs", "Source is not a .mojom file: %s", in.Rel())
+			continue
+		}
+
+		out := android.PathForModuleGen(ctx, in.Rel())
+		m.generatedSrcs = append(m.generatedSrcs, out)
+
+		ctx.ModuleBuild(pctx, android.ModuleBuildParams{
+			Rule:   downgradeMojomTypesRule,
+			Input:  in,
+			Output: out,
+			Args: map[string]string{
+				"outDir":  path.Dir(out.String()),
+			},
+		})
+	}
+}
+
+func (m *mojomDowngradedFiles) GeneratedHeaderDirs() android.Paths {
+	return nil
+}
+
+func (m *mojomDowngradedFiles) GeneratedDeps() android.Paths {
+	return append(android.Paths{}, m.generatedSrcs...)
+}
+
+func (m *mojomDowngradedFiles) GeneratedSourceFiles() android.Paths {
+	return append(android.Paths{}, m.generatedSrcs...)
+}
+
+func (m *mojomDowngradedFiles) Srcs() android.Paths {
+	return append(android.Paths{}, m.generatedSrcs...)
+}
+
+func mojomDowngradedFilesFactory() android.Module {
+	m := &mojomDowngradedFiles{}
+	m.AddProperties(&m.properties)
+	android.InitAndroidModule(m)
+	return m
+}
+
 type mojomPicklesProperties struct {
 	// list of input files
 	Srcs []string
@@ -88,13 +166,14 @@ func (m *mojomPickles) DepsMutator(ctx android.BottomUpMutatorContext) {
 func (m *mojomPickles) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	m.outDir = android.PathForModuleGen(ctx, "")
 
-	packagePath := android.PathForModuleSrc(ctx, "")
-
 	for _, in := range ctx.ExpandSources(m.properties.Srcs, nil) {
 		if !strings.HasSuffix(in.Rel(), ".mojom") {
 			ctx.PropertyErrorf("srcs", "Source is not a .mojom file: %s", in.Rel())
 			continue
 		}
+
+		srcRoot := strings.TrimSuffix(in.String(), in.Rel())
+
 		relStem := strings.TrimSuffix(in.Rel(), ".mojom")
 
 		out := android.PathForModuleGen(ctx, relStem+".p")
@@ -105,9 +184,8 @@ func (m *mojomPickles) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 			Input:  in,
 			Output: out,
 			Args: map[string]string{
-				"package": packagePath.Rel(),
+				"package": srcRoot,
 				"outDir":  m.outDir.String(),
-				"flags":   fmt.Sprintf("-I=%s:%s", packagePath, packagePath),
 			},
 		})
 	}
@@ -237,7 +315,6 @@ func (p *mojomGenerationProperties) generateBuildActions(
 	mojomGenerator string,
 	descriptions []mojomSrcsRuleDescription,
 ) android.Paths {
-	packageName := android.PathForModuleSrc(ctx, "").Rel()
 	outDir := android.PathForModuleGen(ctx, "")
 	implicitDeps := p.implicitDeps(ctx)
 	templateDir := p.templateDir(ctx)
@@ -249,6 +326,7 @@ func (p *mojomGenerationProperties) generateBuildActions(
 			continue
 		}
 		relStem := strings.TrimSuffix(in.Rel(), ".mojom")
+		srcRoot := strings.TrimSuffix(in.String(), in.Rel())
 
 		for _, description := range descriptions {
 			outs := android.WritablePaths{}
@@ -264,7 +342,7 @@ func (p *mojomGenerationProperties) generateBuildActions(
 				Outputs:   outs,
 				Args: map[string]string{
 					"mojomGenerator": mojomGenerator,
-					"package":        packageName,
+					"package":        srcRoot,
 					"flags":          fmt.Sprintf("%s %s", p.flags(ctx), description.extraFlags),
 					"outDir":         outDir.String(),
 					"templateDir":    templateDir,