Issue 5020 - [emscripten] Part 4: Make compile script Windows-compatible

compile

 #!/usr/bin/env python
 
 import argparse
 import os
-import re
 import subprocess
+import sys
 
 BASE_DIR = os.path.dirname(__file__)
 SOURCE_DIR = os.path.join(BASE_DIR, 'compiled')
 SOURCE_FILES = [
     os.path.join(path, f)
     for (path, dirs, files) in os.walk(SOURCE_DIR)
     for f in files
     if f.endswith('.cpp')
 ]
 BINDINGS_FILE = os.path.join(SOURCE_DIR, 'bindings.cpp')
@@ skipping 12 matching lines @@
     'NO_FILESYSTEM': 1,
     'INVOKE_RUN': 0,
     'TEXTDECODER': 0,
     'EXPORTED_RUNTIME_METHODS': ['cwrap', 'ccall', 'stringToAscii'],
 }
 DEFINES = []
 ADDITIONAL_PARAMS = ['-O3', '-m32', '-std=gnu++14', '--memory-init-file', '0',
                      '--emit-symbol-map']
 
 
-def getenv(emscripten_path):
-    path = []
-    env = {}
-    output = subprocess.check_output([
-        '/bin/bash', '-c', os.path.join(emscripten_path, 'emsdk_env.sh')
-    ])
-    for line in output.splitlines():
-        match = re.search(r'^\s*PATH\s*\+=\s*(.*)', line)
-        if match:
-            path.append(match.group(1))
-        match = re.search(r'^\s*(\w+)\s*=\s*(.*)', line)
-        if match:
-            env[match.group(1)] = match.group(2)
-        env['PATH'] = os.pathsep.join([os.environ['PATH']] + path)
+def getenv(emscripten_config):
+    scope = {}
+    execfile(emscripten_config, scope, scope)
+    env = os.environ.copy()
+    env.update({
+        'EM_CONFIG': emscripten_config,

[Wladimir Palant, 2017/03/23 14:10:57]

It seems that Emscripten itself only needs this environment variable, everything
else will be read from the config file.

+        'EMSCRIPTEN': scope['EMSCRIPTEN_ROOT'],
+        'PYTHON': scope.get('PYTHON', sys.executable),
+        'NODE_JS': scope.get('NODE_JS', 'node'),

[Wladimir Palant, 2017/03/23 14:10:57]

This will typically be misconfigured on Windows, see
https://github.com/juj/emsdk/commit/87cb951ec7b9b3388c16c22aa259807a1c901c7a
which still didn't make it into any emsdk releases.

+    })
     return env
 
 
 def generate_bindings(env):
     params = [
-        os.path.join(env['EMSCRIPTEN'], 'emcc'), BINDINGS_FILE,
+        env['PYTHON'], os.path.join(env['EMSCRIPTEN'], 'emcc'), BINDINGS_FILE,
         '-o', BINDINGS_GENERATOR, '-std=gnu++14', '-DPRINT_BINDINGS',
         '-s', 'WARN_ON_UNDEFINED_SYMBOLS=0',
     ]
     subprocess.check_call(params, env=env)
 
-    node = subprocess.check_output('which node', env=env, shell=True).strip()
     with open(BINDINGS_OUTPUT, 'w') as file:
-        subprocess.check_call([node, BINDINGS_GENERATOR], env=env, stdout=file)
+        subprocess.check_call([env['NODE_JS'], BINDINGS_GENERATOR], stdout=file)
 
 
 def run_compiler(env, debug=False, tracing=False):
     params = [
-        os.path.join(env['EMSCRIPTEN'], 'emcc'),
+        env['PYTHON'], os.path.join(env['EMSCRIPTEN'], 'emcc'),
         '-o', COMPILER_OUTPUT,
         '--post-js', BINDINGS_OUTPUT,
     ]
     params.extend(SOURCE_FILES)
     params.extend('-D' + flag for flag in DEFINES)
     for key, value in GENERATION_PARAMS.iteritems():
         params.extend(['-s', '{}={}'.format(key, str(value))])
     if debug:
         params.append('-g1')
     if tracing:
         params.append('--tracing')
     params.extend(ADDITIONAL_PARAMS)
     subprocess.check_call(params, env=env)
 
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(
         description='Compile Emscripten-based C++ code to JavaScript'
     )
     parser.add_argument(
-        '--emscripten',
+        '--emscripten-config',
         metavar='DIR',
-        default=os.path.join(BASE_DIR, '..', 'emscripten'),
+        default=os.path.expanduser('~/.emscripten'),
         help='Emscripten installation directory'
     )
     parser.add_argument(
         '-d', '--debug',
         action='store_true',
         help='Disable code minification'
     )
     parser.add_argument(
         '-t', '--tracing',
         action='store_true',
         help='Enable memory tracing'
     )
     args = parser.parse_args()
 
-    env = getenv(args.emscripten)
+    env = getenv(args.emscripten_config)
     generate_bindings(env)
     run_compiler(env, debug=args.debug, tracing=args.tracing)