6 files changed, 19 insertions, 2 deletions
diff --git a/src/tools/tool-options.h b/src/tools/tool-options.h
index c15291c8d..320cd6ba1 100644
--- a/src/tools/tool-options.h
+++ b/src/tools/tool-options.h
@@ -94,6 +94,7 @@ struct ToolOptions : public Options {
       .addFeature(FeatureSet::GCNNLocals, "GC non-null locals")
       .addFeature(FeatureSet::RelaxedSIMD, "relaxed SIMD")
       .addFeature(FeatureSet::ExtendedConst, "extended const expressions")
+      .addFeature(FeatureSet::Strings, "strings")
       .add("--no-validation",
            "-n",
            "Disables validation, assumes inputs are correct",
diff --git a/src/wasm-binary.h b/src/wasm-binary.h
index a5c6d0a46..c7ac7e7b7 100644
--- a/src/wasm-binary.h
+++ b/src/wasm-binary.h
@@ -437,6 +437,7 @@ extern const char* Memory64Feature;
 extern const char* TypedFunctionReferencesFeature;
 extern const char* RelaxedSIMDFeature;
 extern const char* ExtendedConstFeature;
+extern const char* StringsFeature;
 
 enum Subsection {
   NameModule = 0,
diff --git a/src/wasm-features.h b/src/wasm-features.h
index 64d831ecc..10e4ac4c7 100644
--- a/src/wasm-features.h
+++ b/src/wasm-features.h
@@ -43,11 +43,12 @@ struct FeatureSet {
     GCNNLocals = 1 << 13,
     RelaxedSIMD = 1 << 14,
     ExtendedConst = 1 << 15,
+    Strings = 1 << 16,
     // GCNNLocals are opt-in: merely asking for "All" does not apply them. To
     // get all possible values use AllPossible. See setAll() below for more
     // details.
-    All = ((1 << 16) - 1) & ~GCNNLocals,
-    AllPossible = (1 << 16) - 1,
+    All = ((1 << 17) - 1) & ~GCNNLocals,
+    AllPossible = (1 << 17) - 1,
   };
 
   static std::string toString(Feature f) {
@@ -84,6 +85,8 @@ struct FeatureSet {
         return "relaxed-simd";
       case ExtendedConst:
         return "extended-const";
+      case Strings:
+        return "strings";
       default:
         WASM_UNREACHABLE("unexpected feature");
     }
@@ -130,6 +133,7 @@ struct FeatureSet {
   bool hasGCNNLocals() const { return (features & GCNNLocals) != 0; }
   bool hasRelaxedSIMD() const { return (features & RelaxedSIMD) != 0; }
   bool hasExtendedConst() const { return (features & ExtendedConst) != 0; }
+  bool hasStrings() const { return (features & Strings) != 0; }
   bool hasAll() const { return (features & AllPossible) != 0; }
 
   void set(FeatureSet f, bool v = true) {
@@ -153,6 +157,7 @@ struct FeatureSet {
   void setGCNNLocals(bool v = true) { set(GCNNLocals, v); }
   void setRelaxedSIMD(bool v = true) { set(RelaxedSIMD, v); }
   void setExtendedConst(bool v = true) { set(ExtendedConst, v); }
+  void setStrings(bool v = true) { set(Strings, v); }
   void setMVP() { features = MVP; }
   void setAll() {
     // Do not set GCNNLocals, which forces the user to opt in to that feature
diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index f087e3e4b..263f905fb 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -1101,6 +1101,8 @@ void WasmBinaryWriter::writeFeaturesSection() {
         return BinaryConsts::UserSections::RelaxedSIMDFeature;
       case FeatureSet::ExtendedConst:
         return BinaryConsts::UserSections::ExtendedConstFeature;
+      case FeatureSet::Strings:
+        return BinaryConsts::UserSections::StringsFeature;
       default:
         WASM_UNREACHABLE("unexpected feature flag");
     }
@@ -3416,6 +3418,8 @@ void WasmBinaryBuilder::readFeatures(size_t payloadLen) {
       feature = FeatureSet::RelaxedSIMD;
     } else if (name == BinaryConsts::UserSections::ExtendedConstFeature) {
       feature = FeatureSet::ExtendedConst;
+    } else if (name == BinaryConsts::UserSections::StringsFeature) {
+      feature = FeatureSet::Strings;
     } else {
       // Silently ignore unknown features (this may be and old binaryen running
       // on a new wasm).
diff --git a/src/wasm/wasm-type.cpp b/src/wasm/wasm-type.cpp
index 85f3f0cfc..b13b1ecd7 100644
--- a/src/wasm/wasm-type.cpp
+++ b/src/wasm/wasm-type.cpp
@@ -1165,6 +1165,11 @@ FeatureSet Type::getFeatures() const {
           case HeapType::BasicHeapType::i31:
           case HeapType::BasicHeapType::data:
             return FeatureSet::ReferenceTypes | FeatureSet::GC;
+          case HeapType::string:
+          case HeapType::stringview_wtf8:
+          case HeapType::stringview_wtf16:
+          case HeapType::stringview_iter:
+            return FeatureSet::ReferenceTypes | FeatureSet::Strings;
           default: {}
         }
       }
diff --git a/src/wasm/wasm.cpp b/src/wasm/wasm.cpp
index 428e5093c..86072a880 100644
--- a/src/wasm/wasm.cpp
+++ b/src/wasm/wasm.cpp
@@ -50,6 +50,7 @@ const char* Memory64Feature = "memory64";
 const char* TypedFunctionReferencesFeature = "typed-function-references";
 const char* RelaxedSIMDFeature = "relaxed-simd";
 const char* ExtendedConstFeature = "extended-const";
+const char* StringsFeature = "strings";
 } // namespace UserSections
 } // namespace BinaryConsts