Add type inference for while and do loops.

Analyzer does not type infer these constructs correctly (it uses an
empty context for the loop condition, instead of bool), so the tests
are in inference_new.

R=scheglov@google.com

Review-Url: https://codereview.chromium.org/2954253002 .

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

@@ -2493,7 +2493,7 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
       body = new KernelLabeledStatement(body);
       continueTarget.resolveContinues(body);
     }
-    Statement result = new DoStatement(body, condition);
+    Statement result = new KernelDoStatement(body, condition);
     if (breakTarget.hasUsers) {
       result = new KernelLabeledStatement(result);
       breakTarget.resolveBreaks(result);
@@ -2639,7 +2639,7 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
       body = new KernelLabeledStatement(body);
       continueTarget.resolveContinues(body);
     }
-    Statement result = new WhileStatement(condition, body);
+    Statement result = new KernelWhileStatement(condition, body);
     if (breakTarget.hasUsers) {
       result = new KernelLabeledStatement(result);
       breakTarget.resolveBreaks(result);

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

@@ -552,6 +552,21 @@ class KernelDirectPropertyGet extends DirectPropertyGet
   }
 }
 
+/// Concrete shadow object representing a do loop in kernel form.
+class KernelDoStatement extends DoStatement implements KernelStatement {
+  KernelDoStatement(Statement body, Expression condition)
+      : super(body, condition);
+
+  @override
+  void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.doStatementEnter(this);
+    inferrer.inferStatement(body);
+    inferrer.inferExpression(
+        condition, inferrer.coreTypes.boolClass.rawType, false);
+    inferrer.listener.doStatementExit(this);
+  }
+}
+
 /// Concrete shadow object representing a double literal in kernel form.
 class KernelDoubleLiteral extends DoubleLiteral implements KernelExpression {
   KernelDoubleLiteral(double value) : super(value);
@@ -2236,6 +2251,21 @@ class KernelVariableGet extends VariableGet implements KernelExpression {
   }
 }
 
+/// Concrete shadow object representing a while loop in kernel form.
+class KernelWhileStatement extends WhileStatement implements KernelStatement {
+  KernelWhileStatement(Expression condition, Statement body)
+      : super(condition, body);
+
+  @override
+  void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.whileStatementEnter(this);
+    inferrer.inferExpression(
+        condition, inferrer.coreTypes.boolClass.rawType, false);
+    inferrer.inferStatement(body);
+    inferrer.listener.whileStatementExit(this);
+  }
+}
+
 /// Concrete shadow object representing a yield statement in kernel form.
 class KernelYieldStatement extends YieldStatement implements KernelStatement {
   KernelYieldStatement(Expression expression, {bool isYieldStar: false})

pkg/front_end/lib/src/fasta/type_inference/type_inference_listener.dart

@@ -125,6 +125,12 @@ class TypeInferenceListener
           InvocationExpression expression, DartType inferredType) =>
       debugExpressionExit("constructorInvocation", expression, inferredType);
 
+  void doStatementEnter(DoStatement statement) =>
+      debugStatementEnter("doStatement", statement);
+
+  void doStatementExit(DoStatement statement) =>
+      debugStatementExit("doStatement", statement);
+
   bool doubleLiteralEnter(DoubleLiteral expression, DartType typeContext) =>
       debugExpressionEnter("doubleLiteral", expression, typeContext);
 
@@ -370,6 +376,12 @@ class TypeInferenceListener
   void variableSetExit(VariableSet expression, DartType inferredType) =>
       debugExpressionExit("variableSet", expression, inferredType);
 
+  void whileStatementEnter(WhileStatement statement) =>
+      debugStatementEnter("whileStatement", statement);
+
+  void whileStatementExit(WhileStatement statement) =>
+      debugStatementExit("whileStatement", statement);
+
   void yieldStatementEnter(YieldStatement statement) =>
       debugStatementEnter('yieldStatement', statement);
 

pkg/front_end/testcases/implicit_scope_test.dart.strong.expect

@@ -37,7 +37,7 @@ class ImplicitScopeTest extends core::Object {
       dynamic a = "bar";
       dynamic b = "baz";
     }
-    while ("black".==("white"))
+    while ("black".{core::String::==}("white"))
     exp::Expect::equals("foo", a);
     exp::Expect::equals(null, b);
   }

pkg/front_end/testcases/inference_new/do_loop.dart

@@ -0,0 +1,16 @@
+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+/*@testedFeatures=inference*/
+library test;
+
+T f<T>() => null;
+
+void test() {
+  do {
+    var /*@type=int*/ x = 0;
+  } while (/*@typeArgs=bool*/ f());
+}
+
+main() {}

pkg/front_end/testcases/inference_new/do_loop.dart.direct.expect

@@ -0,0 +1,13 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+static method f<T extends core::Object>() → self::f::T
+  return null;
+static method test() → void {
+  do {
+    dynamic x = 0;
+  }
+  while (self::f<dynamic>())
+}
+static method main() → dynamic {}

pkg/front_end/testcases/inference_new/do_loop.dart.outline.expect

@@ -0,0 +1,10 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+static method f<T extends core::Object>() → self::f::T
+  ;
+static method test() → void
+  ;
+static method main() → dynamic
+  ;

pkg/front_end/testcases/inference_new/do_loop.dart.strong.expect

@@ -0,0 +1,13 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+static method f<T extends core::Object>() → self::f::T
+  return null;
+static method test() → void {
+  do {
+    core::int x = 0;
+  }
+  while (self::f<core::bool>())
+}
+static method main() → dynamic {}

pkg/front_end/testcases/inference_new/while_loop.dart

@@ -0,0 +1,16 @@
+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// 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.
+
+/*@testedFeatures=inference*/
+library test;
+
+T f<T>() => null;
+
+void test() {
+  while (/*@typeArgs=bool*/ f()) {
+    var /*@type=int*/ x = 0;
+  }
+}
+
+main() {}

pkg/front_end/testcases/inference_new/while_loop.dart.direct.expect

@@ -0,0 +1,12 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+static method f<T extends core::Object>() → self::f::T
+  return null;
+static method test() → void {
+  while (self::f<dynamic>()) {
+    dynamic x = 0;
+  }
+}
+static method main() → dynamic {}

pkg/front_end/testcases/inference_new/while_loop.dart.outline.expect

@@ -0,0 +1,10 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+static method f<T extends core::Object>() → self::f::T
+  ;
+static method test() → void
+  ;
+static method main() → dynamic
+  ;

pkg/front_end/testcases/inference_new/while_loop.dart.strong.expect

@@ -0,0 +1,12 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+static method f<T extends core::Object>() → self::f::T
+  return null;
+static method test() → void {
+  while (self::f<core::bool>()) {
+    core::int x = 0;
+  }
+}
+static method main() → dynamic {}

pkg/front_end/testcases/kompile.status

@@ -395,6 +395,7 @@ inference/unsafe_block_closure_inference_method_call_no_type_param: Crash
 inference/void_return_type_subtypes_dynamic: Crash
 inference_new/dependency_only_if_generic_method: Crash
 inference_new/dependency_only_if_overloaded: Crash
+inference_new/do_loop: VerificationError
 inference_new/downwards_inference_inside_top_level: Crash
 inference_new/downwards_inference_inside_top_level_2: Crash
 inference_new/field_inference_circularity: Crash
@@ -415,6 +416,7 @@ inference_new/switch: Crash
 inference_new/unsafe_block_closure_inference_function_call_explicit_dynamic_param_via_expr2: Crash
 inference_new/unsafe_block_closure_inference_function_call_explicit_type_param_via_expr2: Crash
 inference_new/void_return_type_subtypes_dynamic: Crash
+inference_new/while_loop: VerificationError
 
 rasta/abstract_constructor: Fail
 rasta/bad_constructor_redirection: Crash