Parse and print pops of compound types (#4030)

This is necessary when using GC and EH together, for instance.

3 files changed, 45 insertions, 3 deletions

diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index 491e44ca2..8c7b221fd 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -1860,8 +1860,8 @@ struct PrintExpressionContents
   void visitPop(Pop* curr) {
     prepareColor(o) << "pop";
     for (auto type : curr->type) {
-      assert(type.isBasic() && "TODO: print and parse compound types");
-      o << " " << type;
+      o << ' ';
+      printType(o, type, wasm);
     }
     restoreNormalColor(o);
   }
diff --git a/src/wasm/wasm-s-parser.cpp b/src/wasm/wasm-s-parser.cpp
index 019049cb1..c9c8235e2 100644
--- a/src/wasm/wasm-s-parser.cpp
+++ b/src/wasm/wasm-s-parser.cpp
@@ -2159,7 +2159,7 @@ Expression* SExpressionWasmBuilder::makePop(Element& s) {
   auto ret = allocator.alloc<Pop>();
   std::vector<Type> types;
   for (size_t i = 1; i < s.size(); ++i) {
-    types.push_back(stringToType(s[i]->str()));
+    types.push_back(elementToType(*s[i]));
   }
   ret->type = Type(types);
   ret->finalize();
diff --git a/test/lit/gc-eh.wast b/test/lit/gc-eh.wast
new file mode 100644
index 000000000..808060df1
--- /dev/null
+++ b/test/lit/gc-eh.wast
@@ -0,0 +1,42 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py and should not be edited.
+
+;; Check that pops of GC types work correctly.
+
+;; RUN: wasm-opt -all %s -S -o - | filecheck %s
+
+(module
+  ;; CHECK:      (type $A (struct (field (mut i32))))
+  (type $A (struct
+    (field (mut i32))
+  ))
+
+  ;; CHECK:      (tag $tagA (param (ref $A)))
+  (tag $tagA (param (ref $A)))
+
+  ;; CHECK:      (func $foo (result (ref null $A))
+  ;; CHECK-NEXT:  (try $try
+  ;; CHECK-NEXT:   (do
+  ;; CHECK-NEXT:    (nop)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (catch $tagA
+  ;; CHECK-NEXT:    (return
+  ;; CHECK-NEXT:     (pop (ref $A))
+  ;; CHECK-NEXT:    )
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT:  (ref.null $A)
+  ;; CHECK-NEXT: )
+  (func $foo (result (ref null $A))
+    (try
+      (do
+        (nop)
+      )
+      (catch $tagA
+        (return
+          (pop (ref $A))
+        )
+      )
+    )
+    (ref.null $A)
+  )
+)