Fix for tag.wast spec test

check.py

@@ -200,7 +200,9 @@ def check_expected(actual, expected, stdout=None):
 
 UNSPLITTABLE_TESTS = [Path(x) for x in [
     "spec/testsuite/instance.wast",
-    "spec/instance.wast"]]
+    "spec/instance.wast",
+    "spec/testsuite/tag.wast",
+    "spec/tag.wast"]]
 
 
 def is_splittable(wast: Path):
@@ -377,7 +379,6 @@ def run_example_tests():
         subprocess.check_call(cmd)
         print('run...', output_file)
         actual = subprocess.check_output([os.path.abspath(output_file)]).decode('utf-8')
-        os.remove(output_file)
         shared.fail_if_not_identical_to_file(actual, expected)
 
 

scripts/test/shared.py

@@ -425,7 +425,6 @@ def get_tests(test_dir, extensions=[], recursive=False):
     'id.wast',       # Empty IDs should be disallowed
     'instance.wast',  # Requires support for table default elements
     'table64.wast',   # Requires validations for table size
-    'tag.wast',      # Non-empty tag results allowed by stack switching
     'local_init.wast',  # Requires local validation to respect unnamed blocks
     'ref_func.wast',   # Requires rejecting undeclared functions references
     'ref_is_null.wast',  # Requires support for non-nullable reference types in tables

src/ir/import-utils.h

@@ -138,7 +138,7 @@ class ImportResolver {
   virtual RuntimeTable* getTableOrNull(ImportNames name,
                                        const Table& type) const = 0;
 
-  virtual Tag* getTagOrNull(ImportNames name, const Signature& type) const = 0;
+  virtual Tag* getTagOrNull(ImportNames name, HeapType type) const = 0;
 };
 
 // Looks up imports from the given `linkedInstances`.
@@ -170,14 +170,18 @@ class LinkedInstancesImportResolver : public ImportResolver {
     return instance->getExportedTableOrNull(name.name);
   }
 
-  Tag* getTagOrNull(ImportNames name, const Signature& type) const override {
+  Tag* getTagOrNull(ImportNames name, HeapType type) const override {
     auto it = linkedInstances.find(name.module);
     if (it == linkedInstances.end()) {
       return nullptr;
     }
 
     ModuleRunnerType* instance = it->second.get();
-    return instance->getExportedTagOrNull(name.name);
+    auto* tag = instance->getExportedTagOrNull(name.name);
+    if (tag && tag->type != type) {
+      return nullptr;
+    }
+    return tag;
   }
 
 private:

src/parser/contexts.h

@@ -1533,12 +1533,19 @@ struct ParseModuleTypesCtx : TypeParserCtx<ParseModuleTypesCtx>,
 
   Result<> addDeclareElem(Name, ElemListT&&, Index) { return Ok{}; }
 
-  Result<>
-  addTag(Name, const std::vector<Name>&, ImportNames*, TypeUse use, Index pos) {
+  Result<> addTag(Name name,
+                  const std::vector<Name>& exports,
+                  ImportNames* import,
+                  TypeUse use,
+                  Index pos) {
     auto& t = wasm.tags[index];
     if (!use.type.isSignature()) {
       return in.err(pos, "tag type must be a signature");
     }
+    if (use.type.getSignature().results != Type::none &&
+        !wasm.features.hasStackSwitching()) {
+      return in.err(pos, "non-empty tag result type");
+    }
     t->type = use.type;
     return Ok{};
   }

src/tools/execution-results.h

@@ -353,7 +353,7 @@ struct LoggingExternalInterface : public ShellExternalInterface {
 class FuzzerImportResolver
   : public LinkedInstancesImportResolver<ModuleRunner> {
   using LinkedInstancesImportResolver::LinkedInstancesImportResolver;
-  Tag* getTagOrNull(ImportNames name, const Signature& type) const override {
+  Tag* getTagOrNull(ImportNames name, HeapType type) const override {
     if (name.module == "fuzzing-support") {
       if (name.name == "wasmtag") {
         return &wasmTag;

src/tools/wasm-ctor-eval.cpp

@@ -84,14 +84,11 @@ class EvallingImportResolver : public ImportResolver {
     throw FailToEvalException{"Imported table access."};
   }
 
-  // We assume that each tag import is distinct. This is wrong if the same tag
-  // instantiation is imported twice with different import names.
-  Tag* getTagOrNull(ImportNames name,
-                    const Signature& signature) const override {
+  Tag* getTagOrNull(ImportNames name, HeapType type) const override {
     auto [it, inserted] = importedTags.try_emplace(name, Tag{});
     if (inserted) {
       auto& tag = it->second;
-      tag.type = HeapType(signature);
+      tag.type = type;
     }
 
     return &it->second;

src/wasm-interpreter.h

@@ -3478,8 +3478,7 @@ class ModuleRunnerBase : public ExpressionRunner<SubType> {
     for (auto& tag : wasm.tags) {
       if (tag->imported()) {
         auto importNames = tag->importNames();
-        auto importedTag =
-          importResolver->getTagOrNull(importNames, tag->type.getSignature());
+        auto importedTag = importResolver->getTagOrNull(importNames, tag->type);
         if (!importedTag) {
           externalInterface->trap((std::stringstream()
                                    << "Imported tag " << importNames