support -dumpmachine in emcc

emcc

@@ -177,6 +177,10 @@ elif len(sys.argv) == 2 and sys.argv[1] == '-v': # -v with no inputs
   shared.check_sanity(force=True)
   exit(code)
 
+elif '-dumpmachine' in sys.argv:
+  print shared.get_llvm_target()
+  exit(0)
+
 def is_minus_s_for_emcc(newargs, i):
   assert newargs[i] == '-s'
   if i+1 < len(newargs) and '=' in newargs[i+1]: # -s OPT=VALUE is for us, -s by itself is a linker option

tests/test_other.py

@@ -28,6 +28,10 @@ There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR P
       self.assertContained('Display this information', output[0])
       self.assertContained('Most clang options will work', output[0])
 
+      # -dumpmachine
+      output = Popen([PYTHON, compiler, '-dumpmachine'], stdout=PIPE, stderr=PIPE).communicate()
+      self.assertContained(get_llvm_target(), output[0])
+
       # emcc src.cpp ==> writes a.out.js
       self.clear()
       output = Popen([PYTHON, compiler, path_from_root('tests', 'hello_world' + suffix)], stdout=PIPE, stderr=PIPE).communicate()