support -s KEY=@PATH in emcc, for very large settings values

3 files changed, 36 insertions, 4 deletions

diff --git a/emcc b/emcc
index d06bb21c..488f0788 100755
--- a/emcc
+++ b/emcc
@@ -215,6 +215,20 @@ Options that are modified or new in %s include:
                            (without the external "s in either of those,
                            you would get an error)
 
+                           You can also specify a file from which the
+                           value would be read, for example,
+
+                            -s DEAD_FUNCTIONS=@/path/to/file
+
+                           The contents of /path/to/file will be read,
+                           JSON.parsed and set into DEAD_FUNCTIONS (so
+                           the file could contain
+
+                            ["_func1", "func2"]
+
+                           ). Note that the path must be absolute, not
+                           relative.
+
   -g                       Use debug info. Note that you need this during
                            the last compilation phase from bitcode to
                            JavaScript, or else we will remove it by
@@ -973,6 +987,8 @@ try:
   # Apply -s settings in newargs here (after optimization levels, so they can override them)
   for change in settings_changes:
     key, value = change.split('=')
+    if value[0] == '@':
+      value = '"' + value + '"'
     exec('shared.Settings.' + key + ' = ' + value)
 
   # Apply effects from settings
diff --git a/src/compiler.js b/src/compiler.js
index 447d34b7..f461bcf7 100644
--- a/src/compiler.js
+++ b/src/compiler.js
@@ -141,8 +141,13 @@ if (phase == 'pre') {
 
 if (settings_file) {
   var settings = JSON.parse(read(settings_file));
-  for (setting in settings) {
-    eval(setting + ' = ' + JSON.stringify(settings[setting]));
+  for (key in settings) {
+    var value = settings[key];
+    if (value[0] == '@') {
+      // response file type thing, workaround for large inputs: value is @path-to-file
+      value = JSON.parse(read(value.substr(1)));
+    }
+    eval(key + ' = ' + JSON.stringify(value));
   }
 }
 
diff --git a/tests/runner.py b/tests/runner.py
index e5e12b1e..df6c338e 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -7758,17 +7758,28 @@ def process(filename):
       self.emcc_args = map(lambda x: 'ASM_JS=1' if x == 'ASM_JS=0' else x, self.emcc_args)
 
       shutil.move(self.in_dir('src.cpp.o.js'), self.in_dir('pgo.js'))
-      pgo_output = run_js(self.in_dir('pgo.js'))
+      pgo_output = run_js(self.in_dir('pgo.js')).split('\n')[1]
+      open('pgo_data', 'w').write(pgo_output)
+
+      # with response file
 
-      open('pgo_data', 'w').write(pgo_output.split('\n')[1])
       self.emcc_args += ['@pgo_data']
       self.do_run(src, output)
+      self.emcc_args.pop()
       shutil.move(self.in_dir('src.cpp.o.js'), self.in_dir('pgoed.js'))
 
       before = len(open('normal.js').read())
       after = len(open('pgoed.js').read())
       assert after < 0.66 * before, [before, after] # expect a big size reduction
 
+      # with response in settings element itself
+
+      open('dead_funcs', 'w').write(pgo_output[pgo_output.find('['):-1])
+      self.emcc_args += ['-s', 'DEAD_FUNCTIONS=@' + self.in_dir('dead_funcs')]
+      self.do_run(src, output)
+      shutil.move(self.in_dir('src.cpp.o.js'), self.in_dir('pgoed2.js'))
+      assert open('pgoed.js').read() == open('pgoed2.js').read()
+
     def test_scriptaclass(self):
         if self.emcc_args is None: return self.skip('requires emcc')
         if Settings.ASM_JS: return self.skip('asm does not bindings generator yet')