be careful with internalize in llvm LTO, and mark needed symbols for relooper

1 files changed, 11 insertions, 9 deletions

diff --git a/emcc b/emcc
index 1b86ee9b..8151d7c6 100755
--- a/emcc
+++ b/emcc
@@ -1055,17 +1055,19 @@ try:
       if DEBUG: save_intermediate('opt', 'bc')
       # Do LTO in a separate pass to work around LLVM bug XXX (see failure e.g. in cubescript)
     if shared.Building.can_build_standalone():
-      if llvm_lto and shared.Building.can_use_unsafe_opts():
-        if not shared.Building.can_inline(): link_opts.append('-disable-inlining')
-        link_opts.append('-std-link-opts')
-      else:
-        # At least remove dead functions etc., this potentially saves a lot in the size of the generated code (and the time to compile it)
-        exports = ','.join(map(lambda exp: exp[1:], shared.Settings.EXPORTED_FUNCTIONS))
-        link_opts += ['-internalize', '-internalize-public-api-list=' + exports, '-globaldce']
-    if link_opts:
+      # At minimum remove dead functions etc., this potentially saves a lot in the size of the generated code (and the time to compile it)
+      exports = ','.join(map(lambda exp: exp[1:], shared.Settings.EXPORTED_FUNCTIONS))
+      # internalize carefully, llvm 3.2 will remove even main if not told not to
+      link_opts += ['-internalize', '-internalize-public-api-list=' + exports, '-globaldce']
       if DEBUG: print >> sys.stderr, 'emcc: LLVM linktime:', link_opts
       shared.Building.llvm_opt(in_temp(target_basename + '.bc'), link_opts)
-      if DEBUG: save_intermediate('linktime', 'bc')
+      if DEBUG: save_intermediate('dce', 'bc')
+      if llvm_lto and shared.Building.can_use_unsafe_opts():
+        if not shared.Building.can_inline(): link_opts.append('-disable-inlining')
+        link_opts = ['-std-link-opts', '-disable-internalize']
+        if DEBUG: print >> sys.stderr, 'emcc: LLVM linktime:', link_opts
+        shared.Building.llvm_opt(in_temp(target_basename + '.bc'), link_opts)
+        if DEBUG: save_intermediate('linktime', 'bc')
 
   # Prepare .ll for Emscripten
   if not LEAVE_INPUTS_RAW: