Tuple globals (#2718)

Since it wasn't easy to support tuples in Asyncify's call support
using temporary functions, we decided to allow tuple-typed globals
after all. This PR adds support for parsing, printing, lowering, and
interpreting tuple globals and also adds validation ensuring that
imported and exported globals do not have tuple types.

1 files changed, 13 insertions, 8 deletions

diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index 368c01bdc..c152e4b98 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -2137,12 +2137,14 @@ static void validateImports(Module& module, ValidationInfo& info) {
       }
     }
   });
-  if (!module.features.hasMutableGlobals()) {
-    ModuleUtils::iterImportedGlobals(module, [&](Global* curr) {
+  ModuleUtils::iterImportedGlobals(module, [&](Global* curr) {
+    if (!module.features.hasMutableGlobals()) {
       info.shouldBeFalse(
         curr->mutable_, curr->name, "Imported global cannot be mutable");
-    });
-  }
+    }
+    info.shouldBeTrue(
+      curr->type.isSingle(), curr->name, "Imported global cannot be tuple");
+  });
 }
 
 static void validateExports(Module& module, ValidationInfo& info) {
@@ -2164,11 +2166,14 @@ static void validateExports(Module& module, ValidationInfo& info) {
                                "Exported function must not have i64 results");
         }
       }
-    } else if (curr->kind == ExternalKind::Global &&
-               !module.features.hasMutableGlobals()) {
+    } else if (curr->kind == ExternalKind::Global) {
       if (Global* g = module.getGlobalOrNull(curr->value)) {
-        info.shouldBeFalse(
-          g->mutable_, g->name, "Exported global cannot be mutable");
+        if (!module.features.hasMutableGlobals()) {
+          info.shouldBeFalse(
+            g->mutable_, g->name, "Exported global cannot be mutable");
+        }
+        info.shouldBeTrue(
+          g->type.isSingle(), g->name, "Exported global cannot be tuple");
       }
     }
   }