Issue #1624 - Exclude function scopes from Ion compilation.

This seems to work around the problem with the compiled code stack for in-line
declared JS module code. Not optimal, for sure, but better than having to kill
Ion compilation outright.

1 files changed, 8 insertions, 1 deletions

diff --git a/js/src/jsscript.h b/js/src/jsscript.h
index d8d28ebeb..dfe0e486e 100644
--- a/js/src/jsscript.h
+++ b/js/src/jsscript.h
@@ -1443,7 +1443,14 @@ class JSScript : public js::gc::TenuredCell
         return res;
     }
     bool canIonCompile() const {
-        return ion != ION_DISABLED_SCRIPT;
+        // Exclude function scopes from Ion compilation.
+        // This is necessary to work around an issue with module scripts causing crashes
+        // with the function stack in Ion if module code is declared in-line.
+        // See Issue #1624
+        // XXX: Perhaps we can further fine-grain select which types of function scope
+        // we have to exclude?
+        return (ion != ION_DISABLED_SCRIPT &&
+                !bodyScope()->is<js::FunctionScope>());
     }
     bool isIonCompilingOffThread() const {
         return ion == ION_COMPILING_SCRIPT;