[model] Update instructions for generating benchmark data in CFE

Change-Id: I505390321f8ca26391503dd4645b56a208108fc7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/429661
Reviewed-by: Johnni Winther <[email protected]>
Commit-Queue: Chloe Stefantsova <[email protected]>

Author: chloestefantsova

pkg/front_end/test/types/README.md

@@ -16,13 +16,36 @@ To collect new data for a benchmark, follow these steps:
 1. Identify the program that the benchmark is based on, for example,
 `pkg/compiler/lib/src/dart2js.dart`.
 
-2. Modify `pkg/kernel/lib/type_environment.dart` as described in the method
-`SubtypeTester._collect_isSubtypeOf`.
+2. Modify `pkg/kernel/lib/src/types.dart` as described in the method
+`SubtypeTester._collect_performNullabilityAwareSubtypeCheck`.
 
-3. Compile the program using Fasta, for example:
+3. Compile the program using CFE, for example:
 
-    ./sdk/bin/dart pkg/front_end/tool/compile.dart pkg/compiler/lib/src/dart2js.dart
+```shell
+$ ./sdk/bin/dart pkg/front_end/tool/compile.dart pkg/compiler/lib/src/dart2js.dart
+```
 
-4. This produces a file named `type_checks.json` in the current directory.
+This produces a file named `type_checks.json` in the current directory.
 
-5. Compress the file using `gzip`.
+4. Rename the file and compress it using `gzip`:
+
+```shell
+$ mv type_checks.json dart2js.json
+$ gzip dart2js.json
+```
+
+This produces a file named `dart2js.json.gz`.
+
+5. Move the file to the directory `pkg/front_end/test/fasta/types/benchmark_data/` in the Dart SDK checkout:
+
+```shell
+$ mv dart2js.json.gz pkg/front_end/test/fasta/types/benchmark_data/
+```
+
+6. Run the corresponding test:
+
+```shell
+$ python3 tools/test.py -n cfe-unittest-asserts-release-mac --detect-host pkg/front_end/test/types/dart2js_benchmark_test
+```
+
+Note: this will run the test with the locally updated benchmark data. Fresh checkouts of the Dart SDK will not have the updated data.

pkg/front_end/tool/bench_maker.dart

@@ -404,7 +404,8 @@ class BenchMaker implements DartTypeVisitor1<void, StringBuffer> {
   @override
   void visitStructuralParameterType(
       StructuralParameterType node, StringBuffer sb) {
-    throw "not implemented";
+    String name = computeStructuralParameterName(node.parameter);
+    sb.write(name);
   }
 
   @override
@@ -416,12 +417,12 @@ class BenchMaker implements DartTypeVisitor1<void, StringBuffer> {
 
   @override
   void visitTypedefType(TypedefType node, StringBuffer sb) {
-    throw "not implemented";
+    sb.write(node.unalias);
   }
 
   @override
   void visitExtensionType(ExtensionType node, StringBuffer sb) {
-    throw "not implemented";
+    sb.write(node.extensionTypeErasure);
   }
 
   Map<String, dynamic> toJson() {

pkg/kernel/lib/src/types.dart

@@ -58,14 +58,14 @@ class Types with StandardBounds {
   ///    `performNullabilityAwareSubtypeCheck`.
   /// 3. Comment out the call to `_performNullabilityAwareSubtypeCheck` below.
   // ignore:unused_element
-  bool _collect_performNullabilityAwareSubtypeCheck(
-      DartType subtype, DartType supertype, SubtypeCheckMode mode) {
+  IsSubtypeOf _collect_performNullabilityAwareSubtypeCheck(
+      DartType subtype, DartType supertype) {
     IsSubtypeOf result = const IsSubtypeOf.always();
-    //result = _performNullabilityAwareSubtypeCheck(subtype, supertype, mode);
-    bool booleanResult = _isSubtypeFromMode(result, mode);
+    // result = _performNullabilityAwareSubtypeCheck(subtype, supertype);
+    bool booleanResult = result.isSubtypeWhenUsingNullabilities();
     (typeChecksForTesting ??= <Object>[])
         .add([subtype, supertype, booleanResult]);
-    return booleanResult;
+    return result;
   }
 
   IsSubtypeOf performNullabilityAwareSubtypeCheck(DartType s, DartType t) {