[HTML5] Refactor JS, threads support, closures.

- Refactored the Engine code, splitted across files.
- Use MODULARIZE option to build emscripten code into it's own closure.
- Enable lto support (saves ~2MiB in release).
- Enable optional closure compiler pass for JS and generated code.
- Enable optional pthreads support.
- Can now build with tools=yes (not much to see yet).
- Dropped some deprecated code for older toolchains.

1 files changed, 37 insertions, 0 deletions

diff --git a/platform/javascript/emscripten_helpers.py b/platform/javascript/emscripten_helpers.py
new file mode 100644
index 0000000000..bda5b40a74
--- /dev/null
+++ b/platform/javascript/emscripten_helpers.py
@@ -0,0 +1,37 @@
+import os
+
+def parse_config():
+    em_config_file = os.getenv('EM_CONFIG') or os.path.expanduser('~/.emscripten')
+    if not os.path.exists(em_config_file):
+        raise RuntimeError("Emscripten configuration file '%s' does not exist" % em_config_file)
+
+    normalized = {}
+    em_config = {}
+    with open(em_config_file) as f:
+        try:
+            # Emscripten configuration file is a Python file with simple assignments.
+            exec(f.read(), em_config)
+        except StandardError as e:
+            raise RuntimeError("Emscripten configuration file '%s' is invalid:\n%s" % (em_config_file, e))
+    normalized['EMCC_ROOT'] = em_config.get('EMSCRIPTEN_ROOT')
+    normalized['NODE_JS'] = em_config.get('NODE_JS')
+    normalized['CLOSURE_BIN'] = os.path.join(normalized['EMCC_ROOT'], 'node_modules', '.bin', 'google-closure-compiler')
+    return normalized
+
+
+def run_closure_compiler(target, source, env, for_signature):
+    cfg = parse_config()
+    cmd = [cfg['NODE_JS'], cfg['CLOSURE_BIN']]
+    cmd.extend(['--compilation_level', 'ADVANCED_OPTIMIZATIONS'])
+    for f in env['JSEXTERNS']:
+        cmd.extend(['--externs', f.get_abspath()])
+    for f in source:
+        cmd.extend(['--js', f.get_abspath()])
+    cmd.extend(['--js_output_file', target[0].get_abspath()])
+    return ' '.join(cmd)
+
+
+def create_engine_file(env, target, source, externs):
+    if env['use_closure_compiler']:
+        return env.BuildJS(target, source, JSEXTERNS=externs)
+    return env.Textfile(target, [env.File(s) for s in source])