build_modify_js2c_py_to_allow_injection_of_original-fs_and_custom_embedder_js.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Thu, 11 Apr 2019 17:16:13 +0900
Subject: build: modify js2c.py to allow injection of original-fs and custom
 embedder JS

This patch does two things:
* Updates js2c.py so that original-fs is automatically created with
support for streams by copying the file at build time and making a new
builtin called "original-fs" and "original-fs/streams"
* Updates js2c.py so that //electron can call it as part of its build
process and provide embedder modules (electrons
renderer/browser/worker/sandboxed bootstrap scripts).  These are loaded
through LoadEmbedderJavaScriptSource()

diff --git a/src/node_native_module.cc b/src/node_native_module.cc
index 4c3633e06c60265c974bdd2a5a3d2e615e4aeb82..5e03a3a6e35e934faf71e765d7fc6e356f40e8d0 100644
--- a/src/node_native_module.cc
+++ b/src/node_native_module.cc
@@ -20,6 +20,7 @@ NativeModuleLoader NativeModuleLoader::instance_;
 
 NativeModuleLoader::NativeModuleLoader() : config_(GetConfig()) {
   LoadJavaScriptSource();
+  LoadEmbedderJavaScriptSource();
 }
 
 NativeModuleLoader* NativeModuleLoader::GetInstance() {
diff --git a/src/node_native_module.h b/src/node_native_module.h
index 3be3f2364dd252bcdd668c699a0e7ae1e754e873..b2af1bce312ffca44e7005e11f92327e7cb240f6 100644
--- a/src/node_native_module.h
+++ b/src/node_native_module.h
@@ -44,6 +44,7 @@ class NativeModuleLoader {
 
   // Generated by tools/js2c.py as node_javascript.cc
   void LoadJavaScriptSource();  // Loads data into source_
+  void LoadEmbedderJavaScriptSource();  // Loads embedder data into source_
   UnionBytes GetConfig();       // Return data for config.gypi
 
   bool Exists(const char* id);
diff --git a/tools/js2c.py b/tools/js2c.py
index 93e9474297fd9032981786ae9d4e005f2d1a9a2e..bca4c44a31d1ffe7c9ae15b6f60cd55e325f707d 100755
--- a/tools/js2c.py
+++ b/tools/js2c.py
@@ -38,6 +38,8 @@ import functools
 import codecs
 
 def ReadFile(filename):
+  if filename.startswith("//v8"):
+    filename = "../../" + filename[2:]
   if is_verbose:
     print(filename)
   with codecs.open(filename, "r", "utf-8") as f:
@@ -56,13 +58,15 @@ namespace native_module {{
 
 {0}
 
-void NativeModuleLoader::LoadJavaScriptSource() {{
+void NativeModuleLoader::Load{4}JavaScriptSource() {{
   {1}
 }}
 
+#if {2}
 UnionBytes NativeModuleLoader::GetConfig() {{
-  return UnionBytes(config_raw, {2});  // config.gypi
+  return UnionBytes(config_raw, {3});  // config.gypi
 }}
+#endif
 
 }}  // namespace native_module
 
@@ -112,8 +116,8 @@ def GetDefinition(var, source, step=30):
   return definition, len(code_points)
 
 
-def AddModule(filename, definitions, initializers):
-  code = ReadFile(filename)
+def AddModule(filename, definitions, initializers, ReadFileFn=ReadFile):
+  code = ReadFileFn(filename)
   name = NormalizeFileName(filename)
   slug = SLUGGER_RE.sub('_', name)
   var = slug + '_raw'
@@ -123,7 +127,9 @@ def AddModule(filename, definitions, initializers):
   initializers.append(initializer)
 
 def NormalizeFileName(filename):
-  split = filename.split(os.path.sep)
+  if filename.startswith('//v8'):
+    filename = "deps/" + filename[2:]
+  split = os.path.normpath(filename).split(os.path.sep)
   if split[0] == 'deps':
     split = ['internal'] + split
   else:  # `lib/**/*.js` so drop the 'lib' part
@@ -141,7 +147,7 @@ def NormalizeFileName(filename):
   return os.path.splitext(filename)[0]
 
 
-def JS2C(source_files, target):
+def JS2C(source_files, target, only_js):
   # Build source code lines
   definitions = []
   initializers = []
@@ -149,13 +155,26 @@ def JS2C(source_files, target):
   for filename in source_files['.js']:
     AddModule(filename, definitions, initializers)
 
-  config_def, config_size = handle_config_gypi(source_files['config.gypi'])
-  definitions.append(config_def)
+    # Electron: Expose fs module without asar support.
+    if filename == 'lib/fs.js':
+      # Node's 'fs' and 'internal/fs/<filename> have lazy-loaded circular
+      # dependencies. So to expose the unmodified Node 'fs' functionality here,
+      # we have to copy both 'fs' *and* 'internal/fs/<filename>' files and modify the
+      # copies to depend on each other instead of on our asarified 'fs' code.
+      AddModule('lib/original-fs.js', definitions, initializers, lambda _: ReadFile(filename).replace("require('internal/fs/", "require('internal/original-fs/"))
+    elif filename.startswith('lib/internal/fs/'):
+      original_fs_filename = filename.replace('internal/fs/', 'internal/original-fs/')
+      AddModule(original_fs_filename, definitions, initializers, lambda _: ReadFile(filename).replace("require('fs')", "require('original-fs')"))
+
+  config_size = 0
+  if not only_js:
+    config_def, config_size = handle_config_gypi(source_files['config.gypi'])
+    definitions.append(config_def)
 
   # Emit result
   definitions = ''.join(definitions)
   initializers = '\n  '.join(initializers)
-  out = TEMPLATE.format(definitions, initializers, config_size)
+  out = TEMPLATE.format(definitions, initializers, '0' if only_js else '1', config_size, 'Embedder' if only_js else '')
   write_if_chaged(out, target)
 
 
@@ -211,17 +230,21 @@ def main():
   )
   parser.add_argument('--target', help='output file')
   parser.add_argument('--verbose', action='store_true', help='output file')
+  parser.add_argument('--only-js', action='store_true', help='do not require or parse any config.gypi files')
   parser.add_argument('sources', nargs='*', help='input files')
   options = parser.parse_args()
   global is_verbose
   is_verbose = options.verbose
   source_files = functools.reduce(SourceFileByExt, options.sources, {})
   # Should have exactly 2 types: `.js`, and `.gypi`
-  assert len(source_files) == 2
-  # Currently config.gypi is the only `.gypi` file allowed
-  assert source_files['.gypi'] == ['config.gypi']
-  source_files['config.gypi'] = source_files.pop('.gypi')[0]
-  JS2C(source_files, options.target)
+  if options.only_js:
+    assert len(source_files) == 1
+  else:
+    assert len(source_files) == 2
+    # Currently config.gypi is the only `.gypi` file allowed
+    assert source_files['.gypi'][0].endswith('config.gypi')
+    source_files['config.gypi'] = source_files.pop('.gypi')[0]
+  JS2C(source_files, options.target, options.only_js)
 
 
 if __name__ == "__main__":