[cfe] Add always_declare_return_types lint

Change-Id: I206a7a8132b5ea79dc019acf5c2e0cd800307bcf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212161
Reviewed-by: Jens Johansen <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

.dart_tool/package_config.json

@@ -11,7 +11,7 @@
     "constraint, update this by running tools/generate_package_config.dart."
   ],
   "configVersion": 2,
-  "generated": "2021-08-23T16:52:51.727804",
+  "generated": "2021-09-01T12:41:37.776425",
   "generator": "tools/generate_package_config.dart",
   "packages": [
     {
@@ -316,7 +316,7 @@
       "name": "front_end",
       "rootUri": "../pkg/front_end",
       "packageUri": "lib/",
-      "languageVersion": "2.12"
+      "languageVersion": "2.13"
     },
     {
       "name": "front_end_testcases",

pkg/front_end/analysis_options.yaml

@@ -19,4 +19,5 @@ linter:
     - lines_longer_than_80_chars
     - unrelated_type_equality_checks
     - annotate_overrides
+    - always_declare_return_types
     # - always_specify_types

pkg/front_end/benchmarks/ikg/dart2js.dart

@@ -6,4 +6,4 @@
 
 import 'package:compiler/src/dart2js.dart' as dart2js;
 
-main(args) => dart2js.main(args);
+void main(args) => dart2js.main(args);

pkg/front_end/benchmarks/ikg/hello.dart

@@ -2,4 +2,4 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-main() => print('hello world');
+void main() => print('hello world');

pkg/front_end/lib/src/base/libraries_specification.dart

@@ -137,20 +137,19 @@ class LibrariesSpecification {
       if (targetName.startsWith("comment:")) return null;
       Map<String, LibraryInfo> libraries = <String, LibraryInfo>{};
       if (targetData is! Map) {
-        return _reportError(
-            "target specification for '$targetName' is not a map");
+        _reportError("target specification for '$targetName' is not a map");
       }
       if (!targetData.containsKey("libraries")) {
-        return _reportError("target specification "
+        _reportError("target specification "
             "for '$targetName' doesn't have a libraries entry");
       }
       dynamic librariesData = targetData["libraries"];
       if (librariesData is! Map<String, dynamic>) {
-        return _reportError("libraries entry for '$targetName' is not a map");
+        _reportError("libraries entry for '$targetName' is not a map");
       }
       librariesData.forEach((String name, data) {
         if (data is! Map<String, dynamic>) {
-          return _reportError(
+          _reportError(
               "library data for '$name' in target '$targetName' is not a map");
         }
         Uri checkAndResolve(uriString) {
@@ -175,13 +174,12 @@ class LibrariesSpecification {
         } else if (data['patches'] == null) {
           patches = const [];
         } else {
-          return _reportError(
-              "patches entry for '$name' is not a list or a string");
+          _reportError("patches entry for '$name' is not a list or a string");
         }
 
         dynamic supported = data['supported'] ?? true;
         if (supported is! bool) {
-          return _reportError("\"supported\" entry: expected a 'bool' but "
+          _reportError("\"supported\" entry: expected a 'bool' but "
               "got a '${supported.runtimeType}' ('$supported')");
         }
         libraries[name] =
@@ -193,7 +191,7 @@ class LibrariesSpecification {
     return new LibrariesSpecification(targets);
   }
 
-  static _reportError(String error) =>
+  static Never _reportError(String error) =>
       throw new LibrariesSpecificationException(error);
 
   /// Serialize this specification to json.

pkg/front_end/lib/src/base/processed_options.dart

@@ -793,7 +793,7 @@ class ProcessedOptions {
 
   String debugString() {
     StringBuffer sb = new StringBuffer();
-    writeList(String name, List elements) {
+    void writeList(String name, List elements) {
       if (elements.isEmpty) {
         sb.writeln('$name: <empty>');
         return;

pkg/front_end/lib/src/fasta/crash.dart

@@ -50,7 +50,7 @@ void resetCrashReporting() {
 
 Future<T> reportCrash<T>(error, StackTrace trace,
     [Uri? uri, int? charOffset]) async {
-  note(String note) async {
+  Future<void> note(String note) async {
     stderr.write(note);
     await stderr.flush();
   }

pkg/front_end/lib/src/fasta/incremental_compiler.dart

@@ -2097,7 +2097,7 @@ class IncrementalCompiler implements IncrementalKernelGenerator {
       return false;
     }
 
-    addBuilderAndInvalidateUris(Uri uri, LibraryBuilder libraryBuilder) {
+    void addBuilderAndInvalidateUris(Uri uri, LibraryBuilder libraryBuilder) {
       if (uri.scheme == "dart" && !libraryBuilder.isSynthetic) {
         if (seenUris.add(libraryBuilder.importUri)) {
           reusedLibraries.add(libraryBuilder);

pkg/front_end/lib/src/fasta/incremental_serializer.dart

@@ -256,7 +256,7 @@ class IncrementalSerializer {
 
   /// Add the group but not its dependencies to the output if they weren't added
   /// already.
-  addDataButNotDependentData(SerializationGroup group,
+  void addDataButNotDependentData(SerializationGroup group,
       Set<SerializationGroup> cachedPackagesInOutput, Sink<List<int>> sink) {
     if (cachedPackagesInOutput.add(group)) {
       sink.add(group.serializedData);
@@ -265,7 +265,7 @@ class IncrementalSerializer {
 
   /// Add the group and its dependencies to the output if they weren't added
   /// already.
-  addDataAndDependentData(SerializationGroup group,
+  void addDataAndDependentData(SerializationGroup group,
       Set<SerializationGroup> cachedPackagesInOutput, Sink<List<int>> sink) {
     if (cachedPackagesInOutput.add(group)) {
       sink.add(group.serializedData);

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

@@ -1859,7 +1859,7 @@ class BodyBuilder extends ScopeListener<JumpTarget>
   }
 
   @override
-  /* Expression | Generator | Initializer */ finishSend(Object receiver,
+  Expression_Generator_Initializer finishSend(Object receiver,
       List<UnresolvedType>? typeArguments, Arguments arguments, int charOffset,
       {bool isTypeArgumentsInForest = false}) {
     if (receiver is Generator) {
@@ -2445,7 +2445,7 @@ class BodyBuilder extends ScopeListener<JumpTarget>
   /// implies that it shouldn't be turned into a [ThisPropertyAccessGenerator]
   /// if the name doesn't resolve in the scope).
   @override
-  /*Generator|Expression|Builder*/ scopeLookup(
+  Expression_Generator_Builder scopeLookup(
       Scope scope, String name, Token token,
       {bool isQualified: false, PrefixBuilder? prefix}) {
     int charOffset = offsetForToken(token);
@@ -7444,7 +7444,7 @@ class _BodyBuilderCloner extends CloneVisitorNotMembers {
   _BodyBuilderCloner(this.bodyBuilder);
 
   @override
-  visitStaticInvocation(StaticInvocation node) {
+  TreeNode visitStaticInvocation(StaticInvocation node) {
     if (node is FactoryConstructorInvocation) {
       FactoryConstructorInvocation result = new FactoryConstructorInvocation(
           node.target, clone(node.arguments),
@@ -7464,7 +7464,7 @@ class _BodyBuilderCloner extends CloneVisitorNotMembers {
   }
 
   @override
-  visitConstructorInvocation(ConstructorInvocation node) {
+  TreeNode visitConstructorInvocation(ConstructorInvocation node) {
     if (node is TypeAliasedConstructorInvocation) {
       TypeAliasedConstructorInvocation result =
           new TypeAliasedConstructorInvocation(
@@ -7478,7 +7478,7 @@ class _BodyBuilderCloner extends CloneVisitorNotMembers {
   }
 
   @override
-  visitArguments(Arguments node) {
+  TreeNode visitArguments(Arguments node) {
     if (node is ArgumentsImpl) {
       return ArgumentsImpl.clone(node, node.positional.map(clone).toList(),
           node.named.map(clone).toList(), node.types.map(visitType).toList());