emcc option to compress js whitespace

3 files changed, 29 insertions, 5 deletions

diff --git a/emcc b/emcc
index 4264020b..090288b5 100755
--- a/emcc
+++ b/emcc
@@ -155,6 +155,14 @@ Options that are modified or new in %s include:
                            list of arguments, for example, <cmd> of
                            "python processor.py" will cause a python
                            script to be run.
+  --compress <on>          0: Do not compress the generated JavaScript's
+                              whitespace (default if closure compiler
+                              will not be run)
+                           1: Compress the generated JavaScript's
+                              whitespace (default if closure compiler
+                              will be run). Note that this by itself
+                              will not minify the code (closure does
+                              that)
 
 The target file, if specified (-o <target>), defines what will
 be generated:
@@ -272,6 +280,7 @@ try:
   llvm_opt_level = None
   closure = None
   js_transform = None
+  compress_whitespace = None
 
   def check_bad_eq(arg):
     assert '=' not in arg, 'Invalid parameter (do not use "=" with "--" options)'
@@ -300,6 +309,11 @@ try:
       js_transform = newargs[i+1]
       newargs[i] = ''
       newargs[i+1] = ''
+    elif newargs[i].startswith('--compress'):
+      check_bad_eq(newargs[i])
+      compress_whitespace = int(newargs[i+1])
+      newargs[i] = ''
+      newargs[i+1] = ''
     elif newargs[i] == '-MF': # clang cannot handle this, so we fake it
       f = open(newargs[i+1], 'w')
       f.write('\n')
@@ -310,6 +324,8 @@ try:
 
   if llvm_opt_level is None: llvm_opt_level = 1 if opt_level >= 1 else 0
   if closure is None: closure = 1 if opt_level >= 2 else 0
+  if compress_whitespace is None:
+    compress_whitespace = closure # if closure is run, compress whitespace
 
   if closure:
     assert os.path.exists(shared.CLOSURE_COMPILER), 'emcc: fatal: Closure compiler (%s) does not exist' % shared.CLOSURE_COMPILER
@@ -546,6 +562,10 @@ try:
     final = shared.Building.js_optimizer(final, 'simplifyExpressionsPost')
     if DEBUG: save_intermediate('simplifyExpressionsPost')
 
+  if compress_whitespace:
+    final = shared.Building.js_optimizer(final, 'compress')
+    if DEBUG: save_intermediate('compress')
+
   # If we were asked to also generate HTML, do that
   if final_suffix == 'html':
     if DEBUG: print >> sys.stderr, 'emcc: generating HTML'
diff --git a/tests/runner.py b/tests/runner.py
index a23297f6..25eac395 100644
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -5404,7 +5404,7 @@ Options that are modified or new in %s include:
           assert 'SAFE_HEAP' not in generated, 'safe heap should not be used by default'
           assert ': while(' not in generated, 'when relooping we also js-optimize, so there should be no labelled whiles'
           if closure:
-            assert 'Module._main = ' in generated, 'closure compiler should have been run'
+            assert 'Module._main=' in generated, 'closure compiler should have been run (and output should be minified)'
           else:
             # closure has not been run, we can do some additional checks. TODO: figure out how to do these even with closure
             assert 'Module._main = ' not in generated, 'closure compiler should not have been run'
@@ -5415,6 +5415,7 @@ Options that are modified or new in %s include:
             if opt_level >= 1: assert 'HEAP8[HEAP32[' in generated, 'eliminator should create compound expressions, and fewer one-time vars'
             assert ('_puts(' in generated) == (opt_level >= 1), 'with opt >= 1, llvm opts are run and they should optimize printf to puts'
             assert ('function _malloc(bytes) {' in generated) == (not has_malloc), 'If malloc is needed, it should be there, if not not'
+            assert 'function _main() {' in generated, 'Should be unminified, including whitespace'
 
         # emcc -s RELOOP=1 src.cpp ==> should pass -s to emscripten.py. --typed-arrays is a convenient alias for -s USE_TYPED_ARRAYS
         for params, test, text in [
diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js
index a77e0e09..02d7ecb3 100644
--- a/tools/js-optimizer.js
+++ b/tools/js-optimizer.js
@@ -127,10 +127,10 @@ function srcToAst(src) {
   return uglify.parser.parse(src);
 }
 
-function astToSrc(ast) {
+function astToSrc(ast, compress) {
     return uglify.uglify.gen_code(ast, {
     ascii_only: true,
-    beautify: true,
+    beautify: !compress,
     indent_level: 2
   });
 }
@@ -1091,6 +1091,8 @@ function loopOptimizer(ast) {
 
 // Passes table
 
+var compress = false;
+
 var passes = {
   dumpAst: dumpAst,
   dumpSrc: dumpSrc,
@@ -1102,7 +1104,8 @@ var passes = {
   optimizeShiftsAggressive: optimizeShiftsAggressive,
   simplifyExpressionsPost: simplifyExpressionsPost,
   hoistMultiples: hoistMultiples,
-  loopOptimizer: loopOptimizer
+  loopOptimizer: loopOptimizer,
+  compress: function() { compress = true; }
 };
 
 // Main
@@ -1120,6 +1123,6 @@ arguments_.slice(1).forEach(function(arg) {
 //printErr('output: ' + dump(ast));
 //printErr('output: ' + astToSrc(ast));
 ast = srcToAst(astToSrc(ast)); // re-parse, to simplify a little
-print(astToSrc(ast));
+print(astToSrc(ast, compress));
 if (metadata) print(metadata + '\n');