allow emscripten.py to read ~/.emscripten for settings

1 files changed, 14 insertions, 6 deletions

diff --git a/emscripten.py b/emscripten.py
index 46e44605..1d14b81e 100755
--- a/emscripten.py
+++ b/emscripten.py
@@ -3,27 +3,35 @@
 import os, sys, subprocess
 
 COMPILER = os.path.join(os.path.abspath(os.path.dirname(__file__)), 'src', 'parser.js')
+CONFIG_FILE = os.path.expanduser('~/.emscripten')
+JS_ENGINE = None
 
-def emscripten(filename, js_engine, settings):
+if os.path.exists(CONFIG_FILE):
+  exec(open(CONFIG_FILE, 'r').read())
+
+def emscripten(filename, settings):
   data = open(filename, 'r').read()
   cwd = os.getcwd()
   os.chdir(os.path.dirname(COMPILER))
-  subprocess.Popen([js_engine, COMPILER], stdin=subprocess.PIPE).communicate(settings+'\n'+data)[0]
+  subprocess.Popen([JS_ENGINE, COMPILER], stdin=subprocess.PIPE).communicate(settings+'\n'+data)[0]
   os.chdir(cwd)
 
 if __name__ == '__main__':
-  if sys.argv.__len__() not in [3,4]:
+  if sys.argv.__len__() not in [2,3,4]:
     print '''
-Emscripten usage:    emscripten.py INFILE PATH-TO-JS-ENGINE [SETTINGS]
+Emscripten usage:    emscripten.py [INFILE PATH-TO-JS-ENGINE] [SETTINGS]
 
   INFILE must be in human-readable LLVM disassembly form (i.e., as text,
       not binary).
   PATH-TO-JS-ENGINE should be a path to the JavaScript engine used to
       run the compiler (which is in JavaScript itself). You can later use
       the same engine to run the code, or another one, that is a separate
-      issue.
+      issue. If you do not provide this parameter, you should define
+      JS_ENGINE = ... in a file at ~/.emscripten.
   SETTINGS is an optional set of compiler settings, overriding the defaults.
 '''
   else:
-    emscripten(sys.argv[1], sys.argv[2],  sys.argv[3] if len(sys.argv) == 4 else "{}")
+    if len(sys.argv) >= 3:
+      JS_ENGINE = sys.argv[2]
+    emscripten(sys.argv[1], sys.argv[3] if len(sys.argv) == 4 else "{}")