Source maps should only be activated via the --map flag.

Author: int3

emcc

@@ -710,6 +710,7 @@ try:
   save_bc = False
   memory_init_file = False
   use_preload_cache = False
+  make_source_map = False
 
   if use_cxx:
     default_cxx_std = '-std=c++03' # Enforce a consistent C++ standard when compiling .cpp files, if user does not specify one on the cmdline.
@@ -780,6 +781,9 @@ try:
     elif newargs[i] == '-g':
       keep_llvm_debug = True
       keep_js_debug = True
+    elif newargs[i] == '--map':
+      make_source_map = True
+      newargs[i] = '-g' # we'll need this to get LLVM debug info
     elif newargs[i] == '--bind':
       bind = True
       newargs[i] = ''
@@ -869,6 +873,8 @@ 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
+  if make_source_map: keep_llvm_debug = True; keep_js_debug = True
   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
@@ -1498,8 +1504,7 @@ 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,
-            keep_llvm_debug and keep_js_debug)
+        final = shared.Building.js_optimizer(final, js_optimizer_queue, jcache, make_source_map)
         js_transform_tempfiles.append(final)
         if DEBUG: save_intermediate('js_opts')
       else:
@@ -1508,8 +1513,7 @@ 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,
-            keep_llvm_debug and keep_js_debug)
+          final = shared.Building.js_optimizer(final, passes, jcache, make_source_map)
           js_transform_tempfiles.append(final)
           save_intermediate(name)
       js_optimizer_queue = []
@@ -1519,8 +1523,7 @@ try:
 
     if DEBUG == '2':
       # Clean up the syntax a bit
-      final = shared.Building.js_optimizer(final, [], jcache,
-            keep_llvm_debug and keep_js_debug)
+      final = shared.Building.js_optimizer(final, [], jcache, make_source_map)
       if DEBUG: save_intermediate('pretty')
 
     def get_eliminate():
@@ -1608,7 +1611,7 @@ try:
     shell = open(shell_path).read()
     html = open(target, 'w')
     if not Compression.on:
-      if keep_llvm_debug and keep_js_debug:
+      if make_source_map:
         match = re.match('.*?<script[^>]*>{{{ SCRIPT_CODE }}}</script>', shell,
             re.DOTALL)
         if match is None:
@@ -1684,7 +1687,7 @@ try:
         from tools.split import split_javascript_file
         split_javascript_file(final, unsuffixed(target), split_js_file)
     else:
-        if keep_llvm_debug and keep_js_debug: generate_source_map(target)
+        if make_source_map: generate_source_map(target)
 
         # copy final JS to output
         shutil.move(final, target)

tests/runner.py

@@ -9586,7 +9586,7 @@ def process(filename):
 
     def test_source_map(self):
       if Settings.USE_TYPED_ARRAYS != 2: return self.skip("doesn't pass without typed arrays")
-      if '-g' not in Building.COMPILER_TEST_OPTS: Building.COMPILER_TEST_OPTS.append('-g')
+      if '--map' not in Building.COMPILER_TEST_OPTS: Building.COMPILER_TEST_OPTS.append('--map')
 
       src = '''
         #include <stdio.h>
@@ -11754,7 +11754,7 @@ def test_html_source_map(self):
           return 0;
         }
         ''')
-      Popen([PYTHON, EMCC, cpp_file, '-o', html_file,  '-g']).communicate()
+      Popen([PYTHON, EMCC, cpp_file, '-o', html_file,  '--map']).communicate()
       webbrowser.open_new('file://' + html_file)
       print '''
 Set the debugger to pause on exceptions

tools/js_optimizer.py

@@ -57,7 +57,7 @@ def __init__(self, js, js_engine):
           if curr not in INVALID_3: self.names.append(curr)
     #print >> sys.stderr, self.names
 
-  def minify_shell(self, shell, compress, debug=False):
+  def minify_shell(self, shell, compress, source_map=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
@@ -80,7 +80,7 @@ def minify_shell(self, shell, compress, debug=False):
     output = subprocess.Popen(self.js_engine +
         [JS_OPTIMIZER, temp_file, 'minifyGlobals', 'noPrintMetadata'] +
         (['compress'] if compress else []) +
-        (['--debug'] if debug else []),
+        (['--debug'] if source_map 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"
@@ -107,7 +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, debug=False):
+def run_on_js(filename, passes, js_engine, jcache, source_map=False):
   if isinstance(jcache, bool) and jcache: jcache = shared.JCache
   if jcache: shared.JCache.ensure()
 
@@ -175,7 +175,7 @@ def process(line):
       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, debug).split('EMSCRIPTEN_FUNCS();');
+      asm_shell_pre, asm_shell_post = minifier.minify_shell(asm_shell, 'compress' in passes, source_map).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
@@ -211,7 +211,9 @@ def process(line):
   total_size = len(js)
   js = None
 
-  cores = int(os.environ.get('EMCC_CORES') or multiprocessing.cpu_count())
+  # if we are making source maps, we want our debug numbering to start from the
+  # top of the file, so avoid breaking the JS into chunks
+  cores = 1 if source_map else int(os.environ.get('EMCC_CORES') or multiprocessing.cpu_count())
   intended_num_chunks = int(round(cores * NUM_CHUNKS_PER_CORE))
   chunk_size = min(MAX_CHUNK_SIZE, max(MIN_CHUNK_SIZE, total_size / intended_num_chunks))
 
@@ -253,7 +255,7 @@ def write_chunk(chunk, i):
     # 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'] +
-        (['--debug'] if debug else []) + passes, filenames)
+        (['--debug'] if source_map else []) + passes, filenames)
     #print [' '.join(command) for command in commands]
 
     cores = min(cores, filenames)
@@ -321,6 +323,6 @@ def write_chunk(chunk, i):
 
   return filename
 
-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))
+def run(filename, passes, js_engine, jcache, source_map=False):
+  return temp_files.run_and_clean(lambda: run_on_js(filename, passes, js_engine, jcache, source_map))