initial setup

emcc

@@ -1066,6 +1066,16 @@ try:
     logging.warning('disabling LLVM optimizations, need typed arrays mode 2 for them')
     llvm_opts = 0
 
+  if shared.Settings.MAIN_MODULE:
+    assert not shared.Settings.SIDE_MODULE
+    shared.Settings.INCLUDE_FULL_LIBRARY = 1
+    shared.Settings.LINKABLE = 1 # TODO: add FORCE_DCE option for the brave people that do want to dce here and in side modules
+    debug_level = max(debug_level, 2) # preserve function names
+  elif shared.Settings.SIDE_MODULE:
+    assert not shared.Settings.MAIN_MODULE
+    shared.Settings.LINKABLE = 1
+    debug_level = max(debug_level, 2)
+
   ## Compile source code to bitcode
 
   logging.debug('compiling to bitcode')

emlink.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python2
+
+'''
+Fast static linker for emscripten outputs. Specifically this links asm.js modules.
+
+Usage: emlink.py [main module] [side module] [output name]
+
+  Main module should be built with -s MAIN_MODULE=1
+  Side module should be built with -s SIDE_MODULE=1
+
+Note that the output file can be used as a main module, so you can link multiple
+side modules into a main module that way.
+'''
+
+import os, subprocess, sys
+from tools import shared
+
+try:
+  me, main, side, out = sys.argv[:4]
+except:
+  print >> sys.stderr, 'usage: emlink.py [main module] [side module] [output name]'
+  sys.exit(1)
+
+print 'Main module:', main
+print 'Side module:', side
+print 'Output:', out
+

src/settings.js

@@ -296,6 +296,10 @@ var SHOW_LABELS = 0; // Show labels in the generated code
 
 var PRINT_SPLIT_FILE_MARKER = 0; // Prints markers in Javascript generation to split the file later on. See emcc --split option.
 
+var MAIN_MODULE = 0; // A main module is a file compiled in a way that allows us to link it to
+                     // a side module using emlink.py.
+var SIDE_MODULE = 0; // Corresponds to MAIN_MODULE
+
 var BUILD_AS_SHARED_LIB = 0; // Whether to build the code as a shared library
                              // 0 here means this is not a shared lib: It is a main file.
                              // All shared library options (1 and 2) are currently deprecated XXX

tests/runner.py

@@ -10606,6 +10606,25 @@ f.close()
       self.assertContained('hello from lib', run_js(os.path.join(self.get_dir(), 'a.out.js')))
       assert not os.path.exists('a.out') and not os.path.exists('a.exe'), 'Must not leave unneeded linker stubs'
 
+    def zzztest_static_link(self):
+      open(os.path.join(self.get_dir(), 'main.cpp'), 'w').write('''
+        extern void printey();
+        int main() {
+          printey();
+          return 0;
+        }
+      ''')
+      open(os.path.join(self.get_dir(), 'lib.cpp'), 'w').write('''
+        #include <stdio.h>
+        void printey() {
+          printf("hello from lib\\n");
+        }
+      ''')
+      Popen([PYTHON, EMCC, os.path.join(self.get_dir(), 'lib.cpp'), '-o', 'lib.js', '-s', 'SIDE_MODULE=1', '-O2']).communicate()
+      Popen([PYTHON, EMCC, os.path.join(self.get_dir(), 'main.cpp'), '-o', 'main.js', '-s', 'MAIN_MODULE=1', '-O2']).communicate()
+      Popen([PYTHON, EMLINK, 'main.js', 'lib.js', 'together.js'])
+      self.assertContained('hello from lib', run_js('together.js'))
+
     def test_symlink(self):
       if os.name == 'nt':
         return self.skip('Windows FS does not need to be tested for symlinks support, since it does not have them.')

tools/shared.py

@@ -400,6 +400,7 @@ EMAR = path_from_root('emar')
 EMRANLIB = path_from_root('emranlib')
 EMLIBTOOL = path_from_root('emlibtool')
 EMCONFIG = path_from_root('em-config')
+EMLINK = path_from_root('emlink.py')
 EMMAKEN = path_from_root('tools', 'emmaken.py')
 AUTODEBUGGER = path_from_root('tools', 'autodebugger.py')
 BINDINGS_GENERATOR = path_from_root('tools', 'bindings_generator.py')