Make IndexedTypeNameGenerator more powerful (#4511)

Allow IndexedTypeNameGenerator to be configured with a custom prefix and also
allow it to be parameterized with an explicit fallback generator. This allows
multiple IndexedTypeNameGenerators to be composed together, for example.

2 files changed, 81 insertions, 33 deletions

diff --git a/test/example/type-builder-nominal.cpp b/test/example/type-builder-nominal.cpp
index f83648b74..5bfefadc3 100644
--- a/test/example/type-builder-nominal.cpp
+++ b/test/example/type-builder-nominal.cpp
@@ -30,31 +30,35 @@ void test_builder() {
   Struct struct_({Field(refNullArray, Immutable), Field(rttArray, Mutable)});
   Array array(Field(refNullExt, Mutable));
 
-  IndexedTypeNameGenerator print(builder);
-
-  std::cout << "Before setting heap types:\n";
-  std::cout << "$sig => " << print(builder[0]) << "\n";
-  std::cout << "$struct => " << print(builder[1]) << "\n";
-  std::cout << "$array => " << print(builder[2]) << "\n";
-  std::cout << "(ref $sig) => " << print(refSig) << "\n";
-  std::cout << "(ref $struct) => " << print(refStruct) << "\n";
-  std::cout << "(ref $array) => " << print(refArray) << "\n";
-  std::cout << "(ref null $array) => " << print(refNullArray) << "\n";
-  std::cout << "(rtt 0 $array) => " << print(rttArray) << "\n\n";
+  {
+    IndexedTypeNameGenerator print(builder);
+    std::cout << "Before setting heap types:\n";
+    std::cout << "$sig => " << print(builder[0]) << "\n";
+    std::cout << "$struct => " << print(builder[1]) << "\n";
+    std::cout << "$array => " << print(builder[2]) << "\n";
+    std::cout << "(ref $sig) => " << print(refSig) << "\n";
+    std::cout << "(ref $struct) => " << print(refStruct) << "\n";
+    std::cout << "(ref $array) => " << print(refArray) << "\n";
+    std::cout << "(ref null $array) => " << print(refNullArray) << "\n";
+    std::cout << "(rtt 0 $array) => " << print(rttArray) << "\n\n";
+  }
 
   builder[0] = sig;
   builder[1] = struct_;
   builder[2] = array;
 
-  std::cout << "After setting heap types:\n";
-  std::cout << "$sig => " << print(builder[0]) << "\n";
-  std::cout << "$struct => " << print(builder[1]) << "\n";
-  std::cout << "$array => " << print(builder[2]) << "\n";
-  std::cout << "(ref $sig) => " << print(refSig) << "\n";
-  std::cout << "(ref $struct) => " << print(refStruct) << "\n";
-  std::cout << "(ref $array) => " << print(refArray) << "\n";
-  std::cout << "(ref null $array) => " << print(refNullArray) << "\n";
-  std::cout << "(rtt 0 $array) => " << print(rttArray) << "\n\n";
+  {
+    IndexedTypeNameGenerator print(builder);
+    std::cout << "After setting heap types:\n";
+    std::cout << "$sig => " << print(builder[0]) << "\n";
+    std::cout << "$struct => " << print(builder[1]) << "\n";
+    std::cout << "$array => " << print(builder[2]) << "\n";
+    std::cout << "(ref $sig) => " << print(refSig) << "\n";
+    std::cout << "(ref $struct) => " << print(refStruct) << "\n";
+    std::cout << "(ref $array) => " << print(refArray) << "\n";
+    std::cout << "(ref null $array) => " << print(refNullArray) << "\n";
+    std::cout << "(rtt 0 $array) => " << print(rttArray) << "\n\n";
+  }
 
   std::vector<HeapType> built = *builder.build();
 
@@ -64,17 +68,18 @@ void test_builder() {
   Type newRefNullArray = Type(built[2], Nullable);
   Type newRttArray = Type(Rtt(0, built[2]));
 
-  print = IndexedTypeNameGenerator(built);
-
-  std::cout << "After building types:\n";
-  std::cout << "$sig => " << print(built[0]) << "\n";
-  std::cout << "$struct => " << print(built[1]) << "\n";
-  std::cout << "$array => " << print(built[2]) << "\n";
-  std::cout << "(ref $sig) => " << print(newRefSig) << "\n";
-  std::cout << "(ref $struct) => " << print(newRefStruct) << "\n";
-  std::cout << "(ref $array) => " << print(newRefArray) << "\n";
-  std::cout << "(ref null $array) => " << print(newRefNullArray) << "\n";
-  std::cout << "(rtt 0 $array) => " << print(newRttArray) << "\n\n";
+  {
+    IndexedTypeNameGenerator print(built);
+    std::cout << "After building types:\n";
+    std::cout << "$sig => " << print(built[0]) << "\n";
+    std::cout << "$struct => " << print(built[1]) << "\n";
+    std::cout << "$array => " << print(built[2]) << "\n";
+    std::cout << "(ref $sig) => " << print(newRefSig) << "\n";
+    std::cout << "(ref $struct) => " << print(newRefStruct) << "\n";
+    std::cout << "(ref $array) => " << print(newRefArray) << "\n";
+    std::cout << "(ref null $array) => " << print(newRefNullArray) << "\n";
+    std::cout << "(rtt 0 $array) => " << print(newRttArray) << "\n\n";
+  }
 }
 
 // Check that the builder works when there are duplicate definitions
diff --git a/test/gtest/type-builder.cpp b/test/gtest/type-builder.cpp
index 4ae9e0e63..99bec48bf 100644
--- a/test/gtest/type-builder.cpp
+++ b/test/gtest/type-builder.cpp
@@ -1,5 +1,6 @@
-#include <gtest/gtest.h>
-#include <wasm-type.h>
+#include "wasm-type-printing.h"
+#include "wasm-type.h"
+#include "gtest/gtest.h"
 
 using namespace wasm;
 
@@ -101,6 +102,48 @@ TEST_F(TypeTest, TypeIterator) {
   EXPECT_EQ(reverse, tuple.rend());
 }
 
+TEST_F(TypeTest, IndexedTypePrinter) {
+  TypeBuilder builder(4);
+
+  Type refStructA = builder.getTempRefType(builder[0], Nullable);
+  Type refStructB = builder.getTempRefType(builder[1], Nullable);
+  Type refArrayA = builder.getTempRefType(builder[2], Nullable);
+  Type refArrayB = builder.getTempRefType(builder[3], Nullable);
+  builder[0] = Struct({Field(refArrayB, Immutable)});
+  builder[1] = Struct({Field(refStructA, Immutable)});
+  builder[2] = Array(Field(refStructB, Immutable));
+  builder[3] = Array(Field(refArrayA, Immutable));
+
+  auto result = builder.build();
+  ASSERT_TRUE(result);
+  auto built = *result;
+
+  std::vector<HeapType> structs{built[0], built[1]};
+  std::vector<HeapType> arrays{built[2], built[3]};
+
+  // Check that IndexedTypePrinters configured with fallbacks work correctly.
+  using ArrayPrinter = IndexedTypeNameGenerator<DefaultTypeNameGenerator>;
+  ArrayPrinter printArrays(arrays, "array");
+  using StructPrinter = IndexedTypeNameGenerator<ArrayPrinter>;
+  StructPrinter print(structs, printArrays, "struct");
+
+  std::stringstream stream;
+  stream << print(built[0]);
+  EXPECT_EQ(stream.str(), "(struct (field (ref null $array1)))");
+
+  stream.str("");
+  stream << print(built[1]);
+  EXPECT_EQ(stream.str(), "(struct (field (ref null $struct0)))");
+
+  stream.str("");
+  stream << print(built[2]);
+  EXPECT_EQ(stream.str(), "(array (ref null $struct1))");
+
+  stream.str("");
+  stream << print(built[3]);
+  EXPECT_EQ(stream.str(), "(array (ref null $array0))");
+}
+
 TEST_F(EquirecursiveTest, Basics) {
   // (type $sig (func (param (ref $struct)) (result (ref $array) i32)))
   // (type $struct (struct (field (ref null $array) (mut rtt 0 $array))))