Add a TypeNameGenerator that uses names from a Module (#5437)

If the module does not have a name for a particular type, the new utility falls
back to use a different user-configurable type name generator, just like the
existing IndexedTypeNameGenerator does.

Also change how heap types are printed by this printing machinery (which is
currently only used for debugging) so that their names are printed in addition
to their contents. This makes the printer much more useful for debugging.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/wasm-type-printing.h b/src/wasm-type-printing.h
index 685d488fd..3a8740350 100644
--- a/src/wasm-type-printing.h
+++ b/src/wasm-type-printing.h
@@ -24,6 +24,7 @@
 #include "support/name.h"
 #include "support/utilities.h"
 #include "wasm-type.h"
+#include "wasm.h"
 
 namespace wasm {
 
@@ -93,6 +94,33 @@ struct IndexedTypeNameGenerator
   }
 };
 
+// Prints heap types stored in a module, falling back to the given
+// FallbackGenerator if the module does not have a name for type type.
+template<typename FallbackGenerator = DefaultTypeNameGenerator>
+struct ModuleTypeNameGenerator
+  : TypeNameGeneratorBase<ModuleTypeNameGenerator<FallbackGenerator>> {
+  const Module& wasm;
+  DefaultTypeNameGenerator defaultGenerator;
+  FallbackGenerator& fallback;
+
+  ModuleTypeNameGenerator(const Module& wasm, FallbackGenerator& fallback)
+    : wasm(wasm), fallback(fallback) {}
+
+  // TODO: Use C++20 `requires` to clean this up.
+  template<class T = FallbackGenerator>
+  ModuleTypeNameGenerator(
+    const Module& wasm,
+    std::enable_if_t<std::is_same_v<T, DefaultTypeNameGenerator>>* = nullptr)
+    : ModuleTypeNameGenerator(wasm, defaultGenerator) {}
+
+  TypeNames getNames(HeapType type) {
+    if (auto it = wasm.typeNames.find(type); it != wasm.typeNames.end()) {
+      return it->second;
+    }
+    return fallback.getNames(type);
+  }
+};
+
 } // namespace wasm
 
 #endif // wasm_wasm_type_printing_h