From 2b2add48545101de5776c9b26701245c43a8fcb0 Mon Sep 17 00:00:00 2001
From: Ehsan Akhgari <ehsan.akhgari@gmail.com>
Date: Mon, 14 May 2012 20:32:56 -0400
Subject: [PATCH] Add the em-config tool

This tool is useful to use in shell scripts, etc in order to access
variables defined in the ~/.emscripten file without depending on the
details on how to read and parse it.
---
 em-config       | 24 ++++++++++++++++++++++++
 tests/runner.py | 17 +++++++++++++++++
 tools/shared.py |  1 +
 3 files changed, 42 insertions(+)
 create mode 100755 em-config

diff --git a/em-config b/em-config
new file mode 100755
index 000000000..dee399ed9
--- /dev/null
+++ b/em-config
@@ -0,0 +1,24 @@
+#!/usr/bin/env python
+
+'''
+This is a helper tool which is designed to make it possible
+for other apps to read emscripten's configuration variables
+in a unified way.  Usage:
+
+  em-config VAR_NAME
+
+This tool prints the value of the variable to stdout if one
+is found, or exits with 1 if the variable does not exist.
+'''
+
+import os, sys, re
+from tools import shared
+
+if len(sys.argv) != 2 or \
+  not re.match(r"^[\w\W_][\w\W_\d]*$", sys.argv[1]) or \
+  not (sys.argv[1] in dir(shared)):
+  print 'Usage: em-config VAR_NAME'
+  exit(1)
+
+print eval('shared.' + sys.argv[1])
+
diff --git a/tests/runner.py b/tests/runner.py
index a1a3425a9..106ea94c7 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -6094,6 +6094,23 @@ def process(filename):
       '''
       self.do_run(src, 'hello, world!\ncleanup\nExit Status: 118')
 
+    def test_emconfig(self):
+      output = Popen(['python', EMCONFIG, 'LLVM_ROOT'], stdout=PIPE, stderr=PIPE).communicate()[0]
+      assert output == LLVM_ROOT + "\n"
+      invalid = 'Usage: em-config VAR_NAME\n'
+      # Don't accept variables that do not exist
+      output = Popen(['python', EMCONFIG, 'VAR_WHICH_DOES_NOT_EXIST'], stdout=PIPE, stderr=PIPE).communicate()[0]
+      assert output == invalid
+      # Don't accept no arguments
+      output = Popen(['python', EMCONFIG], stdout=PIPE, stderr=PIPE).communicate()[0]
+      assert output == invalid
+      # Don't accept more than one variable
+      output = Popen(['python', EMCONFIG, 'LLVM_ROOT', 'EMCC'], stdout=PIPE, stderr=PIPE).communicate()[0]
+      assert output == invalid
+      # Don't accept arbitrary python code
+      output = Popen(['python', EMCONFIG, 'sys.argv[1]'], stdout=PIPE, stderr=PIPE).communicate()[0]
+      assert output == invalid
+
 
   # Generate tests for everything
   def make_run(fullname, name=-1, compiler=-1, llvm_opts=0, embetter=0, quantum_size=0, typed_arrays=0, emcc_args=None):
diff --git a/tools/shared.py b/tools/shared.py
index c864f6235..b8dc8221f 100644
--- a/tools/shared.py
+++ b/tools/shared.py
@@ -125,6 +125,7 @@ EMAR = path_from_root('emar')
 EMLD = path_from_root('emld')
 EMRANLIB = path_from_root('emranlib')
 EMLIBTOOL = path_from_root('emlibtool')
+EMCONFIG = path_from_root('em-config')
 EMMAKEN = path_from_root('tools', 'emmaken.py')
 AUTODEBUGGER = path_from_root('tools', 'autodebugger.py')
 BINDINGS_GENERATOR = path_from_root('tools', 'bindings_generator.py')