always look for main in .a files

2 files changed, 29 insertions, 1 deletions

diff --git a/tests/runner.py b/tests/runner.py
index af910b2a..26110b59 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -7046,6 +7046,34 @@ f.close()
       err = Popen(['python', EMCC, os.path.join(self.get_dir(), 'main.cpp'), os.path.join(self.get_dir(), 'side.cpp'), '--remove-duplicates'], stderr=PIPE).communicate()[1]
       self.assertContained('bye bye', run_js(os.path.join(self.get_dir(), 'a.out.js')))
 
+    def test_main_a(self):
+      # if main() is in a .a, we need to pull in that .a
+
+      main_name = os.path.join(self.get_dir(), 'main.c')
+      open(main_name, 'w').write(r'''
+        #include <stdio.h>
+        extern int f();
+        int main() {
+          printf("result: %d.\n", f());
+          return 0;
+        }
+      ''')
+
+      other_name = os.path.join(self.get_dir(), 'other.c')
+      open(other_name, 'w').write(r'''
+        #include <stdio.h>
+        int f() { return 12346; }
+      ''')
+
+      Popen(['python', EMCC, main_name, '-c', '-o', main_name+'.bc']).communicate()
+      Popen(['python', EMCC, other_name, '-c', '-o', other_name+'.bc']).communicate()
+
+      Popen(['python', EMAR, 'cr', main_name+'.a', main_name+'.bc']).communicate()
+
+      Popen(['python', EMCC, other_name+'.bc', main_name+'.a']).communicate()
+
+      self.assertContained('result: 12346.', run_js(os.path.join(self.get_dir(), 'a.out.js')))
+
     def test_embed_file(self):
       open(os.path.join(self.get_dir(), 'somefile.txt'), 'w').write('''hello from a file with lots of data and stuff in it thank you very much''')
       open(os.path.join(self.get_dir(), 'main.cpp'), 'w').write(r'''
diff --git a/tools/shared.py b/tools/shared.py
index 3ddf6f47..a74e64b2 100644
--- a/tools/shared.py
+++ b/tools/shared.py
@@ -557,7 +557,7 @@ set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)''' % { 'winfix': '' if not WINDOWS e
   @staticmethod
   def link(files, target, remove_duplicates=False):
     actual_files = []
-    unresolved_symbols = set() # necessary for .a linking, see below
+    unresolved_symbols = set(['main']) # tracking unresolveds is necessary for .a linking, see below. (and main is always a necessary symbol)
     resolved_symbols = set()
     temp_dir = None
     for f in files: