enable aliasing function pointers by default in -O2

1 files changed, 7 insertions, 1 deletions

diff --git a/emcc b/emcc
index 4315219a..d368a4e5 100755
--- a/emcc
+++ b/emcc
@@ -163,7 +163,10 @@ Options that are modified or new in %s include:
                            EMCC_OPTIMIZE_NORMALLY=1 (not recommended
                            unless you know what you are doing!)
   -O2                      As -O1, plus the relooper (loop recreation),
-                           plus LLVM -O2 optimizations
+                           LLVM -O2 optimizations, and
+
+                              -s ALIASING_FUNCTION_POINTERS=1
+
   -O3                      As -O2, plus dangerous optimizations that may
                            break the generated code! This adds
 
@@ -1032,6 +1035,9 @@ try:
       shared.Settings.CORRECT_OVERFLOWS = 1
     assert not shared.Settings.PGO, 'cannot run PGO in ASM_JS mode'
 
+    if shared.Settings.ASSERTIONS and shared.Settings.ALIASING_FUNCTION_POINTERS:
+      logging.warning('ALIASING_FUNCTION_POINTERS is on, function pointer comparisons may be invalid across types')
+
   if shared.Settings.CORRECT_SIGNS >= 2 or shared.Settings.CORRECT_OVERFLOWS >= 2 or shared.Settings.CORRECT_ROUNDINGS >= 2:
     keep_llvm_debug = True # must keep debug info to do line-by-line operations