Make constant expression validation stricter (#5557)

Previously we treated global.get as a constant expression and only
additionally verified that the target globals were immutable in some cases. But
global.get of a mutable global is never a constant expression, and further,
only imported globals are available in constant expressions unless GC is
enabled.

Fix constant expression validation to only allow global.get of immutable,
imported globals, and fix all the invalid tests.

1 files changed, 3 insertions, 20 deletions

diff --git a/src/ir/properties.h b/src/ir/properties.h
index 43f74ceb8..0fee67ad2 100644
--- a/src/ir/properties.h
+++ b/src/ir/properties.h
@@ -453,26 +453,9 @@ inline bool canEmitSelectWithArms(Expression* ifTrue, Expression* ifFalse) {
 //
 bool isGenerative(Expression* curr, FeatureSet features);
 
-inline bool isValidInConstantExpression(Expression* expr, FeatureSet features) {
-  if (isSingleConstantExpression(expr) || expr->is<GlobalGet>() ||
-      expr->is<StructNew>() || expr->is<ArrayNew>() ||
-      expr->is<ArrayNewFixed>() || expr->is<I31New>() ||
-      expr->is<StringConst>()) {
-    return true;
-  }
-
-  if (features.hasExtendedConst()) {
-    if (expr->is<Binary>()) {
-      auto bin = static_cast<Binary*>(expr);
-      if (bin->op == AddInt64 || bin->op == SubInt64 || bin->op == MulInt64 ||
-          bin->op == AddInt32 || bin->op == SubInt32 || bin->op == MulInt32) {
-        return true;
-      }
-    }
-  }
-
-  return false;
-}
+// Whether this expression is valid in a context where WebAssembly requires a
+// constant expression, such as a global initializer.
+bool isValidConstantExpression(Module& wasm, Expression* expr);
 
 } // namespace wasm::Properties