[Strings] Add support for strings in getLiteral and Literal() (#5500)

This is enough for DAE and other opts to run on string consts.

4 files changed, 14 insertions, 6 deletions

diff --git a/src/ir/properties.h b/src/ir/properties.h
index d47ee55a8..fb0065948 100644
--- a/src/ir/properties.h
+++ b/src/ir/properties.h
@@ -116,6 +116,8 @@ inline Literal getLiteral(const Expression* curr) {
     if (auto* c = i->value->dynCast<Const>()) {
       return Literal::makeI31(c->value.geti32());
     }
+  } else if (auto* s = curr->dynCast<StringConst>()) {
+    return Literal(s->string.toString());
   }
   WASM_UNREACHABLE("non-constant expression");
 }
diff --git a/src/literal.h b/src/literal.h
index 5e449c576..317839b72 100644
--- a/src/literal.h
+++ b/src/literal.h
@@ -85,6 +85,7 @@ public:
     assert(type.isSignature());
   }
   explicit Literal(std::shared_ptr<GCData> gcData, HeapType type);
+  explicit Literal(std::string string);
   Literal(const Literal& other);
   Literal& operator=(const Literal& other);
   ~Literal();
diff --git a/src/wasm-interpreter.h b/src/wasm-interpreter.h
index 851c4013c..87b0e0c67 100644
--- a/src/wasm-interpreter.h
+++ b/src/wasm-interpreter.h
@@ -1838,12 +1838,7 @@ public:
     }
   }
   Flow visitStringConst(StringConst* curr) {
-    Literals contents;
-    for (size_t i = 0; i < curr->string.size(); i++) {
-      contents.push_back(Literal(int32_t(curr->string[i])));
-    }
-    auto heapType = curr->type.getHeapType();
-    return Literal(std::make_shared<GCData>(heapType, contents), heapType);
+    return Literal(curr->string.toString());
   }
   Flow visitStringMeasure(StringMeasure* curr) { WASM_UNREACHABLE("unimp"); }
   Flow visitStringEncode(StringEncode* curr) { WASM_UNREACHABLE("unimp"); }
diff --git a/src/wasm/literal.cpp b/src/wasm/literal.cpp
index 80ff47b17..016df2e18 100644
--- a/src/wasm/literal.cpp
+++ b/src/wasm/literal.cpp
@@ -76,6 +76,16 @@ Literal::Literal(std::shared_ptr<GCData> gcData, HeapType type)
   assert((isData() && gcData) || (type.isBottom() && !gcData));
 }
 
+Literal::Literal(std::string string)
+  : gcData(nullptr), type(Type(HeapType::string, NonNullable)) {
+  // TODO: we could in theory internalize strings
+  Literals contents;
+  for (auto c : string) {
+    contents.push_back(Literal(int32_t(c)));
+  }
+  gcData = std::make_shared<GCData>(HeapType::string, contents);
+}
+
 Literal::Literal(const Literal& other) : type(other.type) {
   if (type.isBasic()) {
     switch (type.getBasic()) {