[GC] Directize: Fix subtyping (#7960)

This pass was written before function subtyping, and just checked
equality.

Author: kripken

src/passes/Directize.cpp

@@ -153,7 +153,7 @@ struct FunctionDirectizer : public WalkerPass<PostWalker<FunctionDirectizer>> {
       return CallUtils::Trap{};
     }
     auto* func = getModule()->getFunction(name);
-    if (original->heapType != func->type) {
+    if (!HeapType::isSubType(func->type, original->heapType)) {
       return CallUtils::Trap{};
     }
     return CallUtils::Known{name};

test/lit/passes/directize-gc.wast

@@ -0,0 +1,114 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py --all-items and should not be edited.
+;; NOTE: This test was ported using port_passes_tests_to_lit.py and could be cleaned up.
+
+;; RUN: foreach %s %t wasm-opt --directize -all -S -o - | filecheck %s
+
+;; Call a subtype with the supertype. This call should succeed.
+(module
+ (rec
+  ;; CHECK:      (type $0 (func))
+
+  ;; CHECK:      (rec
+  ;; CHECK-NEXT:  (type $super (sub (func)))
+  (type $super (sub (func)))
+  ;; CHECK:       (type $sub (sub final $super (func)))
+  (type $sub (sub final $super (func)))
+ )
+
+ ;; CHECK:      (table $table 93 funcref)
+ (table $table 93 funcref)
+
+ ;; CHECK:      (elem $elem (i32.const 0) $target)
+ (elem $elem (i32.const 0) $target)
+
+ ;; CHECK:      (export "caller" (func $caller))
+
+ ;; CHECK:      (func $caller (type $0)
+ ;; CHECK-NEXT:  (call $target)
+ ;; CHECK-NEXT: )
+ (func $caller (export "caller")
+  ;; This turns into a direct call.
+  (call_indirect (type $super)
+   (i32.const 0)
+  )
+ )
+
+ ;; CHECK:      (func $target (type $sub)
+ ;; CHECK-NEXT: )
+ (func $target (type $sub)
+ )
+)
+
+;; Remove the subtyping. This call should error.
+(module
+ (rec
+  ;; CHECK:      (type $0 (func))
+
+  ;; CHECK:      (rec
+  ;; CHECK-NEXT:  (type $super (sub (func)))
+  (type $super (sub (func)))
+  ;; CHECK:       (type $other (sub (func)))
+  (type $other (sub (func)))
+ )
+
+ ;; CHECK:      (table $table 93 funcref)
+ (table $table 93 funcref)
+
+ ;; CHECK:      (elem $elem (i32.const 0) $target)
+ (elem $elem (i32.const 0) $target)
+
+ ;; CHECK:      (export "caller" (func $caller))
+
+ ;; CHECK:      (func $caller (type $0)
+ ;; CHECK-NEXT:  (unreachable)
+ ;; CHECK-NEXT: )
+ (func $caller (export "caller")
+  ;; This turns into an unreachable.
+  (call_indirect (type $super)
+   (i32.const 0)
+  )
+ )
+
+ ;; CHECK:      (func $target (type $other)
+ ;; CHECK-NEXT: )
+ (func $target (type $other)
+ )
+)
+
+;; Reverse the subtyping: Call a supertype with a subtype. This call should
+;; fail.
+(module
+ (rec
+  ;; CHECK:      (type $0 (func))
+
+  ;; CHECK:      (rec
+  ;; CHECK-NEXT:  (type $super (sub (func)))
+  (type $super (sub (func)))
+  ;; CHECK:       (type $sub (sub final $super (func)))
+  (type $sub (sub final $super (func)))
+ )
+
+ ;; CHECK:      (table $table 93 funcref)
+ (table $table 93 funcref)
+
+ ;; CHECK:      (elem $elem (i32.const 0) $target)
+ (elem $elem (i32.const 0) $target)
+
+ ;; CHECK:      (export "caller" (func $caller))
+
+ ;; CHECK:      (func $caller (type $0)
+ ;; CHECK-NEXT:  (unreachable)
+ ;; CHECK-NEXT: )
+ (func $caller (export "caller")
+  ;; This turns into a direct call.
+  (call_indirect (type $sub)
+   (i32.const 0)
+  )
+ )
+
+ ;; CHECK:      (func $target (type $super)
+ ;; CHECK-NEXT: )
+ (func $target (type $super)
+ )
+)
+