Disallow tuples in MVP (#2707)

Previously the multivalue feature enabled tuples in control flow
positions, but tuples elsewhere did not require the multivalue
feature. However, allowing tuple operations and locals in MVP modules
means that all passes and tools need to support tuples, even if it
isn't a high priority for them to support multivalue. Allowing tuples
in MVP modules doesn't provide much value, so this changes disallows
them entirely unless multivalue is enabled.

4 files changed, 11 insertions, 1 deletions

diff --git a/src/wasm/wasm-type.cpp b/src/wasm/wasm-type.cpp
index a98d10be4..3fb783fba 100644
--- a/src/wasm/wasm-type.cpp
+++ b/src/wasm/wasm-type.cpp
@@ -198,7 +198,11 @@ Type Type::reinterpret() const {
 
 FeatureSet Type::getFeatures() const {
   FeatureSet feats = FeatureSet::MVP;
-  for (Type t : expand()) {
+  const auto& elements = expand();
+  if (elements.size() > 1) {
+    feats = FeatureSet::Multivalue;
+  }
+  for (Type t : elements) {
     switch (t.getSingle()) {
       case Type::v128:
         feats |= FeatureSet::SIMD;
diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index d81297408..368c01bdc 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -1906,6 +1906,9 @@ void FunctionValidator::visitBrOnExn(BrOnExn* curr) {
 }
 
 void FunctionValidator::visitTupleMake(TupleMake* curr) {
+  shouldBeTrue(getModule()->features.hasMultivalue(),
+               curr,
+               "Tuples are not allowed unless multivalue is enabled");
   std::vector<Type> types;
   for (auto* op : curr->operands) {
     if (op->type == Type::unreachable) {
@@ -1924,6 +1927,9 @@ void FunctionValidator::visitTupleMake(TupleMake* curr) {
 }
 
 void FunctionValidator::visitTupleExtract(TupleExtract* curr) {
+  shouldBeTrue(getModule()->features.hasMultivalue(),
+               curr,
+               "Tuples are not allowed unless multivalue is enabled");
   if (curr->tuple->type == Type::unreachable) {
     shouldBeTrue(
       curr->type == Type::unreachable,
diff --git a/test/passes/asyncify.txt b/test/passes/asyncify_enable-multivalue.txt
index 07fecce10..07fecce10 100644
--- a/test/passes/asyncify.txt
+++ b/test/passes/asyncify_enable-multivalue.txt
diff --git a/test/passes/asyncify.wast b/test/passes/asyncify_enable-multivalue.wast
index b34338bd0..b34338bd0 100644
--- a/test/passes/asyncify.wast
+++ b/test/passes/asyncify_enable-multivalue.wast