2 files changed, 44 insertions, 2 deletions
diff --git a/tools/response_file.py b/tools/response_file.py
new file mode 100644
index 00000000..312cda73
--- /dev/null
+++ b/tools/response_file.py
@@ -0,0 +1,28 @@
+import tempfile, os, sys, shlex
+
+# Routes the given cmdline param list in args into a new response file and returns the filename to it.
+# The returned filename has a suffix '.rsp'.
+def create_response_file(args, directory):
+  (response_fd, response_filename) = tempfile.mkstemp(prefix='emscripten_', suffix='.rsp', dir=directory, text=True)
+  response_fd = os.fdopen(response_fd, "w")
+  #print >> sys.stderr, "Creating response file '%s'" % response_filename
+  args = map(lambda p: p.replace(' ', '').replace('\\', '\\\\').replace('"', '\\"'), args)
+  response_fd.write(' '.join(args))
+  response_fd.close()
+  return response_filename
+
+# Reads a response file, and returns the list of cmdline params found in the file.
+# The parameter response_filename may start with '@'.
+def read_response_file(response_filename):
+  if response_filename.startswith('@'):
+    response_filename = response_filename[1:]
+
+  #print >> sys.stderr, "Using response file '%s'" % response_filename
+  if not os.path.exists(response_filename):
+    raise Exception("Response file '%s' not found!" % response_filename)
+
+  response_fd = open(response_filename, 'r')
+  args = response_fd.read()
+  response_fd.close()
+  args = shlex.split(args)
+  return args
diff --git a/tools/shared.py b/tools/shared.py
index 72f4868e..d5a37c03 100644
--- a/tools/shared.py
+++ b/tools/shared.py
@@ -2,6 +2,7 @@ import shutil, time, os, sys, json, tempfile, copy, shlex, atexit, subprocess, h
 from subprocess import Popen, PIPE, STDOUT
 from tempfile import mkstemp
 import jsrun, cache, tempfiles
+from response_file import create_response_file
 
 def listify(x):
   if type(x) is not list: return [x]
@@ -34,9 +35,15 @@ class WindowsPopen:
         self.stdout_ = PIPE
       if self.stderr_ == None:
         self.stderr_ = PIPE
-  
-    # Call the process with fixed streams.
+
+    # emscripten.py supports reading args from a response file instead of cmdline.
+    # Use .rsp to avoid cmdline length limitations on Windows.
+    if len(args) >= 2 and args[1].endswith("emscripten.py"):
+      self.response_filename = create_response_file(args[2:], TEMP_DIR)
+      args = args[0:2] + ['@' + self.response_filename]
+      
     try:
+      # Call the process with fixed streams.
       self.process = subprocess.Popen(args, bufsize, executable, self.stdin_, self.stdout_, self.stderr_, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags)
     except Exception, e:
       print >> sys.stderr, '\nsubprocess.Popen(args=%s) failed! Exception %s\n' % (' '.join(args), str(e))
@@ -67,6 +74,13 @@ class WindowsPopen:
 
   def kill(self):
     return self.process.kill()
+  
+  def __del__(self):
+    try:
+      # Clean up the temporary response file that was used to spawn this process, so that we don't leave temp files around.
+      tempfiles.try_delete(self.response_filename)
+    except:
+      pass # Mute all exceptions in dtor, particularly if we didn't use a response file, self.response_filename doesn't exist.
 
 # Install our replacement Popen handler if we are running on Windows to avoid python spawn process function.
 if os.name == 'nt':