Lay the groundwork for optimized source maps.

emcc

@@ -869,7 +869,6 @@ try:
   if llvm_opts is None: llvm_opts = LLVM_OPT_LEVEL[opt_level]
   if llvm_lto is None: llvm_lto = opt_level >= 3
   if opt_level <= 0: keep_llvm_debug = keep_js_debug = True # always keep debug in -O0
-  if opt_level > 0: keep_llvm_debug = False # JS optimizer wipes out llvm debug info from being visible
   if closure is None and opt_level == 3: closure = True
 
   if DEBUG: start_time = time.time() # done after parsing arguments, which might affect debug state
@@ -1496,7 +1495,8 @@ try:
         if shared.Settings.ASM_JS:
           js_optimizer_queue = ['asm'] + js_optimizer_queue
         logging.debug('applying js optimization passes: %s', js_optimizer_queue)
-        final = shared.Building.js_optimizer(final, js_optimizer_queue, jcache)
+        final = shared.Building.js_optimizer(final, js_optimizer_queue, jcache,
+            keep_llvm_debug and keep_js_debug)
         if DEBUG: save_intermediate('js_opts')
       else:
         for name in js_optimizer_queue:
@@ -1504,7 +1504,8 @@ try:
           if shared.Settings.ASM_JS:
             passes = ['asm'] + passes
           logging.debug('applying js optimization pass: %s', passes)
-          final = shared.Building.js_optimizer(final, passes, jcache)
+          final = shared.Building.js_optimizer(final, passes, jcache,
+            keep_llvm_debug and keep_js_debug)
           save_intermediate(name)
       js_optimizer_queue = []
 

tools/js-optimizer.js

@@ -11,6 +11,7 @@
 
 // *** Environment setup code ***
 var arguments_ = [];
+var debug = false;
 
 var ENVIRONMENT_IS_NODE = typeof process === 'object';
 var ENVIRONMENT_IS_WEB = typeof window === 'object';
@@ -146,7 +147,7 @@ var generatedFunctions = false; // whether we have received only generated funct
 var minifierInfo = null;
 
 function srcToAst(src) {
-  return uglify.parser.parse(src);
+  return uglify.parser.parse(src, false, debug);
 }
 
 function astToSrc(ast, compress) {
@@ -2750,6 +2751,14 @@ var passes = {
 
 var suffix = '';
 
+arguments_ = arguments_.filter(function (arg) {
+  if (!/^--/.test(arg)) return true;
+
+  if (arg === '--debug') debug = true;
+  else throw new Error('Unrecognized flag: ' + arg);
+});
+
+
 var src = read(arguments_[0]);
 var ast = srcToAst(src);
 //printErr(JSON.stringify(ast)); throw 1;
@@ -2758,6 +2767,7 @@ var minifierInfoStart = src.indexOf('// MINIFY_INFO:')
 if (minifierInfoStart > 0) minifierInfo = JSON.parse(src.substr(minifierInfoStart + 15));
 //printErr(JSON.stringify(minifierInfo));
 
+
 arguments_.slice(1).forEach(function(arg) {
   passes[arg](ast);
 });

tools/js_optimizer.py

@@ -57,7 +57,7 @@ class Minifier:
           if curr not in INVALID_3: self.names.append(curr)
     #print >> sys.stderr, self.names
 
-  def minify_shell(self, shell, compress):
+  def minify_shell(self, shell, compress, debug=False):
     #print >> sys.stderr, "MINIFY SHELL 1111111111", shell, "\n222222222222222"
     # Run through js-optimizer.js to find and minify the global symbols
     # We send it the globals, which it parses at the proper time. JS decides how
@@ -77,7 +77,11 @@ class Minifier:
     f.write('// MINIFY_INFO:' + self.serialize())
     f.close()
 
-    output = subprocess.Popen(self.js_engine + [JS_OPTIMIZER, temp_file, 'minifyGlobals', 'noPrintMetadata'] + (['compress'] if compress else []), stdout=subprocess.PIPE).communicate()[0]
+    output = subprocess.Popen(self.js_engine +
+        [JS_OPTIMIZER, temp_file, 'minifyGlobals', 'noPrintMetadata'] +
+        (['compress'] if compress else []) +
+        (['--debug'] if debug else []),
+        stdout=subprocess.PIPE).communicate()[0]
     assert len(output) > 0 and not output.startswith('Assertion failed'), 'Error in js optimizer: ' + output
     #print >> sys.stderr, "minified SHELL 3333333333333333", output, "\n44444444444444444444"
     code, metadata = output.split('// MINIFY_INFO:')
@@ -103,7 +107,7 @@ def run_on_chunk(command):
   if DEBUG and not shared.WINDOWS: print >> sys.stderr, '.' # Skip debug progress indicator on Windows, since it doesn't buffer well with multiple threads printing to console.
   return filename
 
-def run_on_js(filename, passes, js_engine, jcache):
+def run_on_js(filename, passes, js_engine, jcache, debug=False):
   if isinstance(jcache, bool) and jcache: jcache = shared.JCache
   if jcache: shared.JCache.ensure()
 
@@ -171,7 +175,7 @@ EMSCRIPTEN_FUNCS();
       js = js[start_funcs + len(start_funcs_marker):end_funcs]
 
       minifier = Minifier(js, js_engine)
-      asm_shell_pre, asm_shell_post = minifier.minify_shell(asm_shell, 'compress' in passes).split('EMSCRIPTEN_FUNCS();');
+      asm_shell_pre, asm_shell_post = minifier.minify_shell(asm_shell, 'compress' in passes, debug).split('EMSCRIPTEN_FUNCS();');
       asm_shell_post = asm_shell_post.replace('});', '})');
       pre += asm_shell_pre + '\n' + start_funcs_marker
       post = end_funcs_marker + asm_shell_post + post
@@ -247,7 +251,9 @@ EMSCRIPTEN_FUNCS();
 
   if len(filenames) > 0:
     # XXX Use '--nocrankshaft' to disable crankshaft to work around v8 bug 1895, needed for older v8/node (node 0.6.8+ should be ok)
-    commands = map(lambda filename: js_engine + [JS_OPTIMIZER, filename, 'noPrintMetadata'] + passes, filenames)
+    commands = map(lambda filename: js_engine +
+        [JS_OPTIMIZER, filename, 'noPrintMetadata'] +
+        (['--debug'] if debug else []) + passes, filenames)
     #print [' '.join(command) for command in commands]
 
     cores = min(cores, filenames)
@@ -315,6 +321,6 @@ EMSCRIPTEN_FUNCS();
 
   return filename
 
-def run(filename, passes, js_engine, jcache):
-  return temp_files.run_and_clean(lambda: run_on_js(filename, passes, js_engine, jcache))
+def run(filename, passes, js_engine, jcache, debug=False):
+  return temp_files.run_and_clean(lambda: run_on_js(filename, passes, js_engine, jcache, debug))
 

tools/shared.py

@@ -1213,8 +1213,8 @@ set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)''' % { 'winfix': '' if not WINDOWS e
     return opts
 
   @staticmethod
-  def js_optimizer(filename, passes, jcache):
-    return js_optimizer.run(filename, passes, listify(NODE_JS), jcache)
+  def js_optimizer(filename, passes, jcache, debug):
+    return js_optimizer.run(filename, passes, listify(NODE_JS), jcache, debug)
 
   @staticmethod
   def closure_compiler(filename, pretty=True):