Merge branch 'handle_broken_lli' into glgears

Conflicts:
	src/preamble.js

1 files changed, 200 insertions, 106 deletions

diff --git a/tests/runner.py b/tests/runner.py
index b214c202..a824d089 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -14,7 +14,7 @@ will use 4 processes. To install nose do something like
 '''
 
 from subprocess import Popen, PIPE, STDOUT
-import os, unittest, tempfile, shutil, time, inspect, sys, math, glob, tempfile, re, difflib, webbrowser
+import os, unittest, tempfile, shutil, time, inspect, sys, math, glob, tempfile, re, difflib, webbrowser, hashlib
 
 # Setup
 
@@ -126,12 +126,18 @@ process(sys.argv[1])
   # Build JavaScript code from source code
   def build(self, src, dirname, filename, output_processor=None, main_file=None, additional_files=[], libraries=[], includes=[], build_ll_hook=None, extra_emscripten_args=[], post_build=None):
 
+    Building.pick_llvm_opts(3, safe=Building.LLVM_OPTS != 2) # pick llvm opts here, so we include changes to Settings in the test case code
+
     # Copy over necessary files for compiling the source
     if main_file is None:
       f = open(filename, 'w')
       f.write(src)
       f.close()
-      assert len(additional_files) == 0
+      final_additional_files = []
+      for f in additional_files:
+        final_additional_files.append(os.path.join(dirname, os.path.basename(f)))
+        shutil.copyfile(f, final_additional_files[-1])
+      additional_files = final_additional_files
     else:
       # copy whole directory, and use a specific main .cpp file
       shutil.rmtree(dirname)
@@ -139,10 +145,9 @@ process(sys.argv[1])
       shutil.move(os.path.join(dirname, main_file), filename)
       # the additional files were copied; alter additional_files to point to their full paths now
       additional_files = map(lambda f: os.path.join(dirname, f), additional_files)
+      os.chdir(self.get_dir())
 
     # C++ => LLVM binary
-    os.chdir(dirname)
-    cwd = os.getcwd()
 
     for f in [filename] + additional_files:
       try:
@@ -157,8 +162,6 @@ process(sys.argv[1])
       output = Popen(args, stdout=PIPE, stderr=self.stderr_redirect).communicate()[0]
       assert os.path.exists(f + '.o'), 'Source compilation error: ' + output
 
-    os.chdir(cwd)
-
     # Link all files
     if len(additional_files) + len(libraries) > 0:
       shutil.move(filename + '.o', filename + '.o.alone')
@@ -192,9 +195,6 @@ process(sys.argv[1])
     assert 'strict warning:' not in ret, 'We should pass all strict mode checks: ' + ret
     return ret
 
-  def run_llvm_interpreter(self, args):
-    return Popen([EXEC_LLVM] + args, stdout=PIPE, stderr=self.stderr_redirect).communicate()[0]
-
   def build_native(self, filename):
     Popen([CLANG, '-O2', filename, '-o', filename+'.native'], stdout=PIPE).communicate()[0]
 
@@ -254,6 +254,8 @@ process(sys.argv[1])
 
 sys.argv = map(lambda arg: arg if not arg.startswith('test_') else 'default.' + arg, sys.argv)
 
+Cache.erase() # Wipe the cache, so that we always test populating it in the tests, benchmarks, etc.
+
 if 'benchmark' not in str(sys.argv) and 'sanity' not in str(sys.argv):
   # Tests
 
@@ -261,7 +263,7 @@ if 'benchmark' not in str(sys.argv) and 'sanity' not in str(sys.argv):
 
   class T(RunnerCore): # Short name, to make it more fun to use manually on the commandline
     ## Does a complete test - builds, runs, checks output, etc.
-    def do_run(self, src, expected_output=None, args=[], output_nicerizer=None, output_processor=None, no_build=False, main_file=None, additional_files=[], js_engines=None, post_build=None, basename='src.cpp', libraries=[], includes=[], force_c=False, build_ll_hook=None, extra_emscripten_args=[]):
+    def do_run(self, src, expected_output, args=[], output_nicerizer=None, output_processor=None, no_build=False, main_file=None, additional_files=[], js_engines=None, post_build=None, basename='src.cpp', libraries=[], includes=[], force_c=False, build_ll_hook=None, extra_emscripten_args=[]):
         if force_c or (main_file is not None and main_file[-2:]) == '.c':
           basename = 'src.c'
           Building.COMPILER = to_cc(Building.COMPILER)
@@ -272,11 +274,6 @@ if 'benchmark' not in str(sys.argv) and 'sanity' not in str(sys.argv):
           self.build(src, dirname, filename, main_file=main_file, additional_files=additional_files, libraries=libraries, includes=includes,
                      build_ll_hook=build_ll_hook, extra_emscripten_args=extra_emscripten_args, post_build=post_build)
 
-        # If not provided with expected output, then generate it right now, using lli
-        if expected_output is None:
-          expected_output = self.run_llvm_interpreter([filename + '.o'])
-          print '[autogenerated expected output: %20s]' % (expected_output[0:30].replace('\n', '|')+'...')
-
         # Run in both JavaScript engines, if optimizing - significant differences there (typed arrays)
         if js_engines is None:
           js_engines = JS_ENGINES
@@ -651,7 +648,7 @@ if 'benchmark' not in str(sys.argv) and 'sanity' not in str(sys.argv):
             return 0;
           }
         '''
-        self.do_run(src)#, '*4294967295,0,4294967219*\n*-1,1,-1,1*\n*-2,1,-2,1*\n*246,296*\n*1,0*')
+        self.do_run(src, '*4294967295,0,4294967219*\n*-1,1,-1,1*\n*-2,1,-2,1*\n*246,296*\n*1,0*')
 
         # Now let's see some code that should just work in USE_TYPED_ARRAYS == 2, but requires
         # corrections otherwise
@@ -865,7 +862,7 @@ if 'benchmark' not in str(sys.argv) and 'sanity' not in str(sys.argv):
           }
         '''
 
-        self.do_run(src)
+        self.do_run(src, '*1800*')
 
         generated = open('src.cpp.o.js', 'r').read()
         assert '__label__ ==' not in generated, 'We should hoist into the loop'
@@ -1174,8 +1171,13 @@ if 'benchmark' not in str(sys.argv) and 'sanity' not in str(sys.argv):
         self.do_run(src, 'Assertion failed: 1 == false')
 
     def test_exceptions(self):
+        if Settings.QUANTUM_SIZE == 1: return self.skip("we don't support libcxx in q1")
+
         self.banned_js_engines = [NODE_JS] # node issue 1669, exception causes stdout not to be flushed
         Settings.DISABLE_EXCEPTION_CATCHING = 0
+        if self.emcc_args is None:
+          if Building.LLVM_OPTS: return self.skip('optimizing bitcode before emcc can confuse libcxx inclusion')
+          self.emcc_args = [] # libc++ auto-inclusion is only done if we use emcc
 
         src = '''
           #include <stdio.h>
@@ -2354,7 +2356,10 @@ def process(filename):
             return 0;
           }
           '''
-        self.do_run(src)
+        def check(result):
+          return hashlib.sha1(result).hexdigest()
+        self.do_run(src, '6c9cdfe937383b79e52ca7a2cce83a21d9f5422c',
+                    output_nicerizer = check)
 
     def test_memmove(self):
       src = '''
@@ -2367,7 +2372,7 @@ def process(filename):
           return 0;
         }
       '''
-      self.do_run(src)
+      self.do_run(src, 'memmove can be very very useful')
 
     def test_bsearch(self):
       if Settings.QUANTUM_SIZE == 1: return self.skip('Test cannot work with q1')
@@ -2502,6 +2507,9 @@ def process(filename):
 
     def test_runtimelink(self):
       if Building.LLVM_OPTS: return self.skip('LLVM opts will optimize printf into puts in the parent, and the child will still look for puts')
+
+      Settings.LINKABLE = 1
+
       self.banned_js_engines = [NODE_JS] # node's global scope behaves differently than everything else, needs investigation FIXME
 
       header = r'''
@@ -2562,6 +2570,8 @@ def process(filename):
       self.do_run(main, 'supp: 54,2\nmain: 56\nsupp see: 543\nmain see: 76\nok.')
 
     def test_dlfcn_basic(self):
+      Settings.LINKABLE = 1
+
       lib_src = '''
         #include <cstdio>
 
@@ -2611,6 +2621,8 @@ def process(filename):
                   post_build=add_pre_run_and_checks)
 
     def test_dlfcn_qsort(self):
+      Settings.LINKABLE = 1
+
       if Settings.USE_TYPED_ARRAYS == 2:
         Settings.CORRECT_SIGNS = 1 # Needed for unsafe optimizations
 
@@ -2703,6 +2715,8 @@ def process(filename):
     def test_dlfcn_data_and_fptr(self):
       if Building.LLVM_OPTS: return self.skip('LLVM opts will optimize out parent_func')
 
+      Settings.LINKABLE = 1
+
       lib_src = '''
         #include <stdio.h>
 
@@ -2801,6 +2815,8 @@ def process(filename):
                    post_build=add_pre_run_and_checks)
 
     def test_dlfcn_alias(self):
+      Settings.LINKABLE = 1
+
       if Building.LLVM_OPTS == 2: return self.skip('LLVM LTO will optimize away stuff we expect from the shared library')
 
       lib_src = r'''
@@ -2853,6 +2869,8 @@ def process(filename):
       Settings.INCLUDE_FULL_LIBRARY = 0
 
     def test_dlfcn_varargs(self):
+      Settings.LINKABLE = 1
+
       if Building.LLVM_OPTS == 2: return self.skip('LLVM LTO will optimize things that prevent shared objects from working')
       if Settings.QUANTUM_SIZE == 1: return self.skip('FIXME: Add support for this')
 
@@ -3130,21 +3148,21 @@ at function.:blag
         #include <stdlib.h>
 
         int main () {
-          printf("%d\n", atoi(""));
-          printf("%d\n", atoi("a"));
-          printf("%d\n", atoi(" b"));
-          printf("%d\n", atoi(" c "));
-          printf("%d\n", atoi("6"));
-          printf("%d\n", atoi(" 5"));
-          printf("%d\n", atoi("4 "));
-          printf("%d\n", atoi("3 6"));
-          printf("%d\n", atoi(" 3 7"));
-          printf("%d\n", atoi("9 d"));
+          printf("%d*", atoi(""));
+          printf("%d*", atoi("a"));
+          printf("%d*", atoi(" b"));
+          printf("%d*", atoi(" c "));
+          printf("%d*", atoi("6"));
+          printf("%d*", atoi(" 5"));
+          printf("%d*", atoi("4 "));
+          printf("%d*", atoi("3 6"));
+          printf("%d*", atoi(" 3 7"));
+          printf("%d*", atoi("9 d"));
           printf("%d\n", atoi(" 8 e"));
           return 0;
         }
         '''
-      self.do_run(src)
+      self.do_run(src, '0*0*0*0*6*5*4*3*3*9*8')
 
     def test_sscanf(self):
       src = r'''
@@ -3170,7 +3188,8 @@ at function.:blag
           return 0;
         }
         '''
-      self.do_run(src)
+      self.do_run(src, 'en-us : 2*en-r : 99*en : 3*1.234567, 0.000000',
+                  output_nicerizer = lambda x: x.replace('\n', '*'))
 
       # Part 2: doubles (issue 148)
       if Settings.USE_TYPED_ARRAYS == 2:
@@ -3221,7 +3240,11 @@ Pass: 123456.789063 123456.789063
 Pass: 0.000012 0.000012
 Pass: 0.000012 0.000012''')
           else:
-            self.do_run(src)
+            self.do_run(src, '''Pass: 1.234568 1.234568
+Pass: 123456.789000 123456.789000
+Pass: 123456.789000 123456.789000
+Pass: 0.000012 0.000012
+Pass: 0.000012 0.000012''')
 
     def test_langinfo(self):
       src = open(path_from_root('tests', 'langinfo', 'test.c'), 'r').read()
@@ -3834,9 +3857,40 @@ def process(filename):
       self.do_run(src, expected)
       CORRECT_SIGNS = 0
 
+    def test_atomic(self):
+      src = '''
+        #include <stdio.h>
+        int main() {
+          int x = 10;
+          int y = __sync_add_and_fetch(&x, 5);
+          printf("*%d,%d*\\n", x, y);
+          x = 10;
+          y = __sync_fetch_and_add(&x, 5);
+          printf("*%d,%d*\\n", x, y);
+          x = 10;
+          y = __sync_lock_test_and_set(&x, 6);
+          printf("*%d,%d*\\n", x, y);
+          x = 10;
+          y = __sync_bool_compare_and_swap(&x, 9, 7);
+          printf("*%d,%d*\\n", x, y);
+          y = __sync_bool_compare_and_swap(&x, 10, 7);
+          printf("*%d,%d*\\n", x, y);
+          return 0;
+        }
+      '''
+
+      self.do_run(src, '*15,15*\n*15,10*\n*6,10*\n*10,0*\n*7,1*')
+
     # libc++ tests
 
     def test_iostream(self):
+      if Settings.QUANTUM_SIZE == 1: return self.skip("we don't support libcxx in q1")
+
+      if self.emcc_args is None:
+        if Building.LLVM_OPTS: return self.skip('optimizing bitcode before emcc can confuse libcxx inclusion')
+        self.emcc_args = [] # libc++ auto-inclusion is only done if we use emcc
+        Settings.SAFE_HEAP = 0 # Some spurious warnings from libc++ internals
+
       src = '''
         #include <iostream>
 
@@ -3847,7 +3901,8 @@ def process(filename):
         }
       '''
 
-      self.do_run(src, 'hello world\n77.\n')
+      # FIXME: should not have so many newlines in output here
+      self.do_run(src, 'hello world\n\n77.\n')
 
     def test_stdvec(self):
       src = '''
@@ -3907,11 +3962,13 @@ def process(filename):
           self.do_run(src, j, [str(i)], lambda x: x.replace('\n', '*'), no_build=i>1)
 
     def test_dlmalloc(self):
+      if self.emcc_args is None: self.emcc_args = [] # dlmalloc auto-inclusion is only done if we use emcc
+
       Settings.CORRECT_SIGNS = 2
       Settings.CORRECT_SIGNS_LINES = ['src.cpp:' + str(i+4) for i in [4816, 4191, 4246, 4199, 4205, 4235, 4227]]
       Settings.TOTAL_MEMORY = 100*1024*1024 # needed with typed arrays
 
-      src = open(path_from_root('src', 'dlmalloc.c'), 'r').read() + '\n\n\n' + open(path_from_root('tests', 'dlmalloc_test.c'), 'r').read()
+      src = open(path_from_root('system', 'lib', 'dlmalloc.c'), 'r').read() + '\n\n\n' + open(path_from_root('tests', 'dlmalloc_test.c'), 'r').read()
       self.do_run(src, '*1,0*', ['200', '1'])
       self.do_run(src, '*400,0*', ['400', '400'], no_build=True)
 
@@ -3942,13 +3999,9 @@ def process(filename):
           self.do_run(src.replace('{{{ NEW }}}', new).replace('{{{ DELETE }}}', delete), '*1,0*')
 
     def test_libcxx(self):
-      self.do_run(path_from_root('tests', 'libcxx'),
-                   'june -> 30\nPrevious (in alphabetical order) is july\nNext (in alphabetical order) is march',
-                   main_file='main.cpp', additional_files=['hash.cpp'])
+      self.do_run(open(path_from_root('tests', 'hashtest.cpp')).read(),
+                   'june -> 30\nPrevious (in alphabetical order) is july\nNext (in alphabetical order) is march')
 
-      # This will fail without using libcxx, as libstdc++ (gnu c++ lib) will use but not link in 
-      # __ZSt29_Rb_tree_insert_and_rebalancebPSt18_Rb_tree_node_baseS0_RS_
-      # So a way to avoid that problem is to include libcxx, as done here
       self.do_run('''
         #include <set>
         #include <stdio.h>
@@ -3958,7 +4011,7 @@ def process(filename):
           printf("hello world\\n");
           return 1;
         }
-        ''', 'hello world', includes=[path_from_root('tests', 'libcxx', 'include')]);
+        ''', 'hello world');
         
     def test_static_variable(self):
       Settings.SAFE_HEAP = 0 # LLVM mixes i64 and i8 in the guard check
@@ -4079,7 +4132,7 @@ def process(filename):
     def get_freetype(self):
       Settings.INIT_STACK = 1 # TODO: Investigate why this is necessary
 
-      return self.get_library('freetype', os.path.join('objs', '.libs', 'libfreetype.a.bc'))
+      return self.get_library('freetype', os.path.join('objs', '.libs', 'libfreetype.a'))
 
     def test_freetype(self):
       if Settings.QUANTUM_SIZE == 1: return self.skip('TODO: Figure out and try to fix')
@@ -4109,6 +4162,7 @@ def process(filename):
 
     def test_sqlite(self):
       # gcc -O3 -I/home/alon/Dev/emscripten/tests/sqlite -ldl src.c
+      if self.emcc_args is None: return self.skip('Very slow without ta2, and we would also need to include dlmalloc manually without emcc')
       if Settings.QUANTUM_SIZE == 1: return self.skip('TODO FIXME')
 
       pgo_data = read_pgo_data(path_from_root('tests', 'sqlite', 'sqlite-autooptimize.fails.txt'))
@@ -4146,7 +4200,6 @@ def process(filename):
                    open(path_from_root('tests', 'sqlite', 'benchmark.txt'), 'r').read(),
                    includes=[path_from_root('tests', 'sqlite')],
                    force_c=True,
-                   extra_emscripten_args=['-m'],
                    js_engines=[SPIDERMONKEY_ENGINE], # V8 is slow
                    post_build=post)#,build_ll_hook=self.do_autodebug)
 
@@ -4158,7 +4211,7 @@ def process(filename):
 
       self.do_run(open(path_from_root('tests', 'zlib', 'example.c'), 'r').read(),
                    open(path_from_root('tests', 'zlib', 'ref.txt'), 'r').read(),
-                   libraries=[self.get_library('zlib', os.path.join('libz.a.bc'), make_args=['libz.a'])],
+                   libraries=[self.get_library('zlib', os.path.join('libz.a'), make_args=['libz.a'])],
                    includes=[path_from_root('tests', 'zlib')],
                    force_c=True)
 
@@ -4175,9 +4228,9 @@ def process(filename):
       self.do_run(open(path_from_root('tests', 'bullet', 'Demos', 'HelloWorld', 'HelloWorld.cpp'), 'r').read(),
                    [open(path_from_root('tests', 'bullet', 'output.txt'), 'r').read(), # different roundings
                     open(path_from_root('tests', 'bullet', 'output2.txt'), 'r').read()],
-                   libraries=[self.get_library('bullet', [os.path.join('src', '.libs', 'libBulletCollision.a.bc'),
-                                                          os.path.join('src', '.libs', 'libBulletDynamics.a.bc'),
-                                                          os.path.join('src', '.libs', 'libLinearMath.a.bc')],
+                   libraries=[self.get_library('bullet', [os.path.join('src', '.libs', 'libBulletCollision.a'),
+                                                          os.path.join('src', '.libs', 'libBulletDynamics.a'),
+                                                          os.path.join('src', '.libs', 'libLinearMath.a')],
                                                configure_args=['--disable-demos','--disable-dependency-tracking'])],
                    includes=[path_from_root('tests', 'bullet', 'src')],
                    js_engines=[SPIDERMONKEY_ENGINE]) # V8 issue 1407
@@ -4223,9 +4276,9 @@ def process(filename):
 
       poppler = self.get_library('poppler',
                                  [os.path.join('poppler', '.libs', 'libpoppler.so.13.0.0'),
-                                  os.path.join('goo', '.libs', 'libgoo.a.bc'),
-                                  os.path.join('fofi', '.libs', 'libfofi.a.bc'),
-                                  os.path.join('splash', '.libs', 'libsplash.a.bc'),
+                                  os.path.join('goo', '.libs', 'libgoo.a'),
+                                  os.path.join('fofi', '.libs', 'libfofi.a'),
+                                  os.path.join('splash', '.libs', 'libsplash.a'),
                                   os.path.join('utils', 'pdftoppm.o'),
                                   os.path.join('utils', 'parseargs.o')],
                                  configure_args=['--disable-libjpeg', '--disable-libpng', '--disable-poppler-qt', '--disable-poppler-qt4', '--disable-cms'])
@@ -4336,8 +4389,7 @@ def process(filename):
 
       self.do_ll_run(path_from_root('tests', 'python', 'python.ll'),
                       'hello python world!\n[0, 2, 4, 6]\n5\n22\n5.470000',
-                      args=['-S', '-c' '''print "hello python world!"; print [x*2 for x in range(4)]; t=2; print 10-3-t; print (lambda x: x*2)(11); print '%f' % 5.47'''],
-                      extra_emscripten_args=['-m'])
+                      args=['-S', '-c' '''print "hello python world!"; print [x*2 for x in range(4)]; t=2; print 10-3-t; print (lambda x: x*2)(11); print '%f' % 5.47'''])
 
     # Test cases in separate files. Note that these files may contain invalid .ll!
     # They are only valid enough for us to read for test purposes, not for llvm-as
@@ -4405,7 +4457,28 @@ def process(filename):
       self.do_autodebug(filename)
 
       # Compare to each other, and to expected output
-      self.do_ll_run(path_from_root('tests', filename+'.o.ll.ll'))
+      self.do_ll_run(path_from_root('tests', filename+'.o.ll.ll'), '''AD:-1,15
+AD:15,0
+AD:21,5
+AD:24,6
+AD:27,101
+AD:30,7009
+AD:37,5
+AD:40,10
+AD:45,7009
+AD:48,7008
+AD:54,7008
+AD:57,7018
+AD:60,10
+AD:63,6
+AD:66,101
+AD:69,7018
+AD:73,101
+AD:77,7018
+AD:81,101
+AD:85,7018
+*10,6,101,7018,101,7018,101,7018*''')
+      assert open('stdout').read().startswith('AD:-1'), 'We must note when we enter functions'
 
       # Test using build_ll_hook
       src = '''
@@ -4423,30 +4496,17 @@ def process(filename):
             return 0;
           }
         '''
-      self.do_run(src, build_ll_hook=self.do_autodebug)
-      self.do_run(src, 'AD:', build_ll_hook=self.do_autodebug)
-
-    def test_dfe(self):
-      def hook(filename):
-        ll = open(filename + '.o.ll').read()
-        assert 'unneeded' not in ll, 'DFE should remove the unneeded function'
-
-      src = '''
-          #include <stdio.h>
-
-          void unneeded()
-          {
-            printf("some totally useless stuff\\n");
-          }
-
-          int main()
-          {
-            printf("*hello slim world*\\n");
-            return 0;
-          }
-        '''
-      # Using build_ll_hook forces a recompile, which leads to DFE being done even without opts
-      self.do_run(src, '*hello slim world*', build_ll_hook=hook)
+      self.do_run(src, '''AD:-1,13
+AD:13,0
+AD:16,25
+AD:20,51
+AD:23,25
+AD:26,25
+AD:29,11.520000
+AD:31,25
+AD:33,51
+AD:36,11.520000
+*25,51,11.52*''', build_ll_hook=self.do_autodebug)
 
     def test_profiling(self):
       src = '''
@@ -4981,26 +5041,6 @@ def process(filename):
         # This test *should* fail
         assert 'Assertion failed' in str(e), str(e)
 
-    def test_autoassemble(self):
-      src = r'''
-        #include <stdio.h>
-
-        int main() {
-          puts("test\n");
-          return 0;
-        }
-        '''
-      dirname = self.get_dir()
-      filename = os.path.join(dirname, 'src.cpp')
-      self.build(src, dirname, filename)
-
-      new_filename = os.path.join(dirname, 'new.bc')
-      shutil.copy(filename + '.o', new_filename)
-      Building.emscripten(new_filename, append_ext=False)
-
-      shutil.copy(filename + '.o.js', os.path.join(self.get_dir(), 'new.cpp.o.js'))
-      self.do_run(None, 'test\n', basename='new.cpp', no_build=True)
-
     def test_linespecific(self):
       Settings.CHECK_SIGNS = 0
       Settings.CHECK_OVERFLOWS = 0
@@ -5361,10 +5401,16 @@ Options that are modified or new in %s include:
         for args in [['-c'], ['-o', 'src.o'], ['-o', 'src.bc'], ['-o', 'js']]:
           target = args[1] if len(args) == 2 else 'hello_world.o'
           clear()
-          output = Popen([compiler, path_from_root('tests', 'hello_world' + suffix)] + args, stdout=PIPE, stderr=PIPE).communicate()
+          Popen([compiler, path_from_root('tests', 'hello_world' + suffix)] + args, stdout=PIPE, stderr=PIPE).communicate()
+          syms = Building.llvm_nm(target)
+          assert len(syms.defs) == 1 and 'main' in syms.defs, 'Failed to generate valid bitcode'
+          if target == 'js': # make sure emcc can recognize the target as a bitcode file
+            shutil.move(target, target + '.bc')
+            target += '.bc'
+          output = Popen([compiler, target, '-o', target + '.js'], stdout = PIPE, stderr = PIPE).communicate()
           assert len(output[0]) == 0, output[0]
-          assert os.path.exists(target), 'Expected %s to exist since args are %s : %s' % (target, str(args), '\n'.join(output))
-          self.assertContained('hello, world!', self.run_llvm_interpreter([target]))
+          assert os.path.exists(target + '.js'), 'Expected %s to exist since args are %s : %s' % (target + '.js', str(args), '\n'.join(output))
+          self.assertContained('hello, world!', run_js(target + '.js'))
 
         # emcc src.ll ==> generates .js
         clear()
@@ -5509,8 +5555,12 @@ Options that are modified or new in %s include:
           try_delete(target)
           assert not os.path.exists(target)
           output = Popen([compiler, 'twopart_main.o', 'twopart_side.o', '-o', 'combined.bc'] + args, stdout=PIPE, stderr=PIPE).communicate()
-          assert os.path.exists('combined.bc'), '\n'.join(output)
-          self.assertContained('side got: hello from main, over', self.run_llvm_interpreter(['combined.bc']))
+          syms = Building.llvm_nm('combined.bc')
+          assert len(syms.defs) == 2 and 'main' in syms.defs, 'Failed to generate valid bitcode'
+          output = Popen([compiler, 'combined.bc', '-o', 'combined.bc.js'], stdout = PIPE, stderr = PIPE).communicate()
+          assert len(output[0]) == 0, output[0]
+          assert os.path.exists('combined.bc.js'), 'Expected %s to exist' % ('combined.bc.js')
+          self.assertContained('side got: hello from main, over', run_js('combined.bc.js'))
 
         # --js-transform <transform>
         clear()
@@ -5859,7 +5909,7 @@ elif 'benchmark' in str(sys.argv):
 
     def test_dlmalloc(self):
       # XXX This seems to have regressed slightly with emcc. Are -g and the signs lines passed properly?
-      src = open(path_from_root('src', 'dlmalloc.c'), 'r').read() + '\n\n\n' + open(path_from_root('tests', 'dlmalloc_test.c'), 'r').read()
+      src = open(path_from_root('system', 'lib', 'dlmalloc.c'), 'r').read() + '\n\n\n' + open(path_from_root('tests', 'dlmalloc_test.c'), 'r').read()
       self.do_benchmark(src, ['400', '400'], '*400,0*', emcc_args=['-g', '-s', 'CORRECT_SIGNS=2', '-s', 'CORRECT_SIGNS_LINES=[4820, 4195, 4250, 4203, 4209, 4239, 4231]'])
 
 elif 'sanity' in str(sys.argv):
@@ -5887,6 +5937,9 @@ elif 'sanity' in str(sys.argv):
 
   commands = [[EMCC], ['python', path_from_root('tests', 'runner.py'), 'blahblah']]
 
+  def mtime(filename):
+    return os.stat(filename).st_mtime
+
   class sanity(RunnerCore):
     def setUp(self):
       wipe()
@@ -5974,9 +6027,6 @@ elif 'sanity' in str(sys.argv):
       assert os.path.exists('a.out.js')
 
     def test_emcc(self):
-      def mtime(filename):
-        return os.stat(filename).st_mtime
-
       SANITY_MESSAGE = 'Emscripten: Running sanity checks'
       SANITY_FAIL_MESSAGE = 'sanity check failed to run'
 
@@ -6014,6 +6064,50 @@ elif 'sanity' in str(sys.argv):
       assert mtime(SANITY_FILE) >= mtime(CONFIG_FILE)
       self.assertNotContained(SANITY_FAIL_MESSAGE, output)
 
+    def test_emcc_caching(self):
+      INCLUDING_MESSAGE = 'emcc: including X'
+      BUILDING_MESSAGE = 'emcc: building X for cache'
+
+      EMCC_CACHE = Cache.dirname
+
+      restore()
+
+      Cache.erase()
+      assert not os.path.exists(EMCC_CACHE)
+
+      try:
+        emcc_debug = os.environ.get('EMCC_DEBUG')
+        os.environ['EMCC_DEBUG'] ='1'
+
+        # Building a file that doesn't need cached stuff should not trigger cache generation
+        output = self.do([EMCC, path_from_root('tests', 'hello_world.cpp')])
+        assert INCLUDING_MESSAGE.replace('X', 'dlmalloc') not in output
+        assert BUILDING_MESSAGE.replace('X', 'dlmalloc') not in output
+        self.assertContained('hello, world!', run_js('a.out.js'))
+        assert not os.path.exists(EMCC_CACHE)
+        try_delete('a.out.js')
+
+        # Building a file that *does* need dlmalloc *should* trigger cache generation, but only the first time
+        for filename, libname in [('hello_malloc.cpp', 'dlmalloc'), ('hello_libcxx.cpp', 'libcxx')]:
+          for i in range(3):
+            try_delete(os.path.join(EMSCRIPTEN_TEMP_DIR, 'emcc-0-bc.bc')) # we might need to check this file later
+            output = self.do([EMCC, path_from_root('tests', filename)])
+            assert INCLUDING_MESSAGE.replace('X', libname) in output
+            if libname == 'dlmalloc':
+              assert INCLUDING_MESSAGE.replace('X', 'libcxx') not in output # we don't need libcxx in this code
+            else:
+              assert INCLUDING_MESSAGE.replace('X', 'dlmalloc') in output # libcxx always forces inclusion of dlmalloc
+            assert (BUILDING_MESSAGE.replace('X', libname) in output) == (i == 0), 'Must only build the first time'
+            self.assertContained('hello, world!', run_js('a.out.js'))
+            assert os.path.exists(EMCC_CACHE)
+            assert os.path.exists(os.path.join(EMCC_CACHE, libname + '.bc'))
+            if libname == 'libcxx':
+              assert os.stat(os.path.join(EMCC_CACHE, libname + '.bc')).st_size > 4000000, 'libc++ is big'
+              assert os.stat(os.path.join(EMSCRIPTEN_TEMP_DIR, 'emcc-0-bc.bc')).st_size < 2000000, 'Dead code elimination must remove most of libc++'
+      finally:
+        if emcc_debug:
+          os.environ['EMCC_DEBUG'] = emcc_debug
+
 else:
   raise Exception('Test runner is confused: ' + str(sys.argv))