[cfe] Implement the desugaring for RelationalPattern

Part of #49749

Change-Id: I8b1da2a3c3f25e5147a519cf3d05e3ac2e42f401
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/267341
Reviewed-by: Johnni Winther <[email protected]>
Commit-Queue: Chloe Stefantsova <[email protected]>

Author: chloestefantsova

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

@@ -831,6 +831,21 @@ class Forest {
       ..fileOffset = fileOffset;
   }
 
+  EqualsCall createEqualsCall(int fileOffset, Expression left, Expression right,
+      FunctionType functionType, Procedure interfaceTarget) {
+    // ignore: unnecessary_null_comparison
+    assert(fileOffset != null);
+    return new EqualsCall(left, right,
+        functionType: functionType, interfaceTarget: interfaceTarget)
+      ..fileOffset = fileOffset;
+  }
+
+  EqualsNull createEqualsNull(int fileOffset, Expression expression) {
+    // ignore: unnecessary_null_comparison
+    assert(fileOffset != null);
+    return new EqualsNull(expression)..fileOffset = fileOffset;
+  }
+
   BinaryExpression createBinary(
       int fileOffset, Expression left, Name binaryName, Expression right) {
     // ignore: unnecessary_null_comparison

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

@@ -26,6 +26,7 @@ import 'package:_fe_analyzer_shared/src/type_inference/type_analyzer.dart';
 import 'package:_fe_analyzer_shared/src/type_inference/type_analysis_result.dart';
 
 import '../builder/type_alias_builder.dart';
+import '../fasta_codes.dart';
 import '../names.dart';
 import '../problems.dart' show unsupported;
 import '../type_inference/inference_visitor.dart';
@@ -5499,8 +5500,76 @@ class RelationalPattern extends Pattern {
   @override
   Expression? makeCondition(VariableDeclaration matchedExpressionVariable,
       InferenceVisitorBase inferenceVisitor) {
-    return new InvalidExpression(
-        "Unimplemented RelationalMatcher.makeCondition");
+    DartType receiverType = matchedExpressionVariable.type;
+    Name name;
+    switch (kind) {
+      case RelationalPatternKind.equals:
+      case RelationalPatternKind.notEquals:
+        Expression result;
+        if (expression is NullLiteral || expression is NullConstant) {
+          result = inferenceVisitor.engine.forest.createEqualsNull(
+              fileOffset,
+              inferenceVisitor.engine.forest
+                  .createVariableGet(fileOffset, matchedExpressionVariable));
+        } else {
+          ObjectAccessTarget target = inferenceVisitor.findInterfaceMember(
+              receiverType, equalsName, fileOffset,
+              callSiteAccessKind: CallSiteAccessKind.operatorInvocation);
+          result = inferenceVisitor.engine.forest.createEqualsCall(
+              fileOffset,
+              inferenceVisitor.engine.forest
+                  .createVariableGet(fileOffset, matchedExpressionVariable),
+              expression,
+              target.getFunctionType(inferenceVisitor),
+              target.member as Procedure);
+        }
+        if (kind == RelationalPatternKind.notEquals) {
+          result = inferenceVisitor.engine.forest.createNot(fileOffset, result);
+        }
+        return result;
+      case RelationalPatternKind.lessThan:
+        name = lessThanName;
+        break;
+      case RelationalPatternKind.lessThanEqual:
+        name = lessThanOrEqualsName;
+        break;
+      case RelationalPatternKind.greaterThan:
+        name = greaterThanName;
+        break;
+      case RelationalPatternKind.greaterThanEqual:
+        name = greaterThanOrEqualsName;
+        break;
+    }
+    ObjectAccessTarget target = inferenceVisitor.findInterfaceMember(
+        receiverType, name, fileOffset,
+        callSiteAccessKind: CallSiteAccessKind.operatorInvocation);
+    if (target.kind == ObjectAccessTargetKind.dynamic) {
+      return new DynamicInvocation(
+          DynamicAccessKind.Dynamic,
+          inferenceVisitor.engine.forest
+              .createVariableGet(fileOffset, matchedExpressionVariable),
+          name,
+          inferenceVisitor.engine.forest
+              .createArguments(fileOffset, [expression]));
+    } else if (target.member is! Procedure) {
+      inferenceVisitor.helper.addProblem(
+          templateUndefinedOperator.withArguments(
+              name.text, receiverType, inferenceVisitor.isNonNullableByDefault),
+          matchedExpressionVariable.fileOffset,
+          noLength);
+      return null;
+    } else {
+      return new InstanceInvocation(
+          InstanceAccessKind.Instance,
+          inferenceVisitor.engine.forest
+              .createVariableGet(fileOffset, matchedExpressionVariable),
+          name,
+          inferenceVisitor.engine.forest
+              .createArguments(fileOffset, [expression]),
+          functionType: target.getFunctionType(inferenceVisitor),
+          interfaceTarget: target.member as Procedure)
+        ..fileOffset = fileOffset;
+    }
   }
 
   @override

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

@@ -7856,7 +7856,9 @@ class InferenceVisitorImpl extends InferenceVisitorBase
       required Map<VariableDeclaration, VariableTypeInfo<Node, DartType>>
           typeInfos,
       required MatchContext<Node, Expression> context}) {
-    // TODO(cstefantsova): Should the expression be inferred?
+    ExpressionInferenceResult expressionResult =
+        inferExpression(matcher.expression, matchedType, true);
+    matcher.expression = expressionResult.expression..parent = matcher;
     return const PatternInferenceResult();
   }
 

pkg/front_end/testcases/patterns/relational_inside_if_case.dart

@@ -1,3 +1,17 @@
+// Copyright (c) 2022, 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.
+
 test(dynamic x) {
   if (x case == 1) {}
+  if (x case == null) {}
+  if (x case == 'foo'.length) {}
+  if (x case != 1) {}
+  if (x case != null) {}
+  if (x case < 1) {}
+  if (x case <= 1) {}
+  if (x case > 1) {}
+  if (x case >= 1) {}
 }
+
+main() {}

pkg/front_end/testcases/patterns/relational_inside_if_case.dart.strong.expect

@@ -1,8 +1,34 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "dart:core" as core;
 
 static method test(dynamic x) → dynamic {
   final dynamic #t1 = x;
-  if(invalid-expression "Unimplemented RelationalMatcher.makeCondition") {
+  if(#t1 =={core::Object::==}{(core::Object) → core::bool} 1) {
+  }
+  final dynamic #t2 = x;
+  if(#t2 == null) {
+  }
+  final dynamic #t3 = x;
+  if(#t3 =={core::Object::==}{(core::Object) → core::bool} "foo".{core::String::length}{core::int}) {
+  }
+  final dynamic #t4 = x;
+  if(!(#t4 =={core::Object::==}{(core::Object) → core::bool} 1)) {
+  }
+  final dynamic #t5 = x;
+  if(!(#t5 == null)) {
+  }
+  final dynamic #t6 = x;
+  if(#t6{dynamic}.<(1)) {
+  }
+  final dynamic #t7 = x;
+  if(#t7{dynamic}.<=(1)) {
+  }
+  final dynamic #t8 = x;
+  if(#t8{dynamic}.>(1)) {
+  }
+  final dynamic #t9 = x;
+  if(#t9{dynamic}.>=(1)) {
   }
 }
+static method main() → dynamic {}

pkg/front_end/testcases/patterns/relational_inside_if_case.dart.strong.transformed.expect

@@ -1,8 +1,39 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "dart:core" as core;
 
 static method test(dynamic x) → dynamic {
   final dynamic #t1 = x;
-  if(invalid-expression "Unimplemented RelationalMatcher.makeCondition") {
+  if(#t1 =={core::Object::==}{(core::Object) → core::bool} 1) {
+  }
+  final dynamic #t2 = x;
+  if(#t2 == null) {
+  }
+  final dynamic #t3 = x;
+  if(#t3 =={core::Object::==}{(core::Object) → core::bool} "foo".{core::String::length}{core::int}) {
+  }
+  final dynamic #t4 = x;
+  if(!(#t4 =={core::Object::==}{(core::Object) → core::bool} 1)) {
+  }
+  final dynamic #t5 = x;
+  if(!(#t5 == null)) {
+  }
+  final dynamic #t6 = x;
+  if(#t6{dynamic}.<(1)) {
+  }
+  final dynamic #t7 = x;
+  if(#t7{dynamic}.<=(1)) {
+  }
+  final dynamic #t8 = x;
+  if(#t8{dynamic}.>(1)) {
+  }
+  final dynamic #t9 = x;
+  if(#t9{dynamic}.>=(1)) {
   }
 }
+static method main() → dynamic {}
+
+
+Extra constant evaluation status:
+Evaluated: InstanceGet @ org-dartlang-testcase:///relational_inside_if_case.dart:8:23 -> IntConstant(3)
+Extra constant evaluation: evaluated: 30, effectively constant: 1

pkg/front_end/testcases/patterns/relational_inside_if_case.dart.textual_outline.expect

@@ -1 +1,2 @@
 test(dynamic x) {}
+main() {}

pkg/front_end/testcases/patterns/relational_inside_if_case.dart.textual_outline_modelled.expect

@@ -1 +1,2 @@
+main() {}
 test(dynamic x) {}

pkg/front_end/testcases/patterns/relational_inside_if_case.dart.weak.expect

@@ -1,8 +1,34 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "dart:core" as core;
 
 static method test(dynamic x) → dynamic {
   final dynamic #t1 = x;
-  if(invalid-expression "Unimplemented RelationalMatcher.makeCondition") {
+  if(#t1 =={core::Object::==}{(core::Object) → core::bool} 1) {
+  }
+  final dynamic #t2 = x;
+  if(#t2 == null) {
+  }
+  final dynamic #t3 = x;
+  if(#t3 =={core::Object::==}{(core::Object) → core::bool} "foo".{core::String::length}{core::int}) {
+  }
+  final dynamic #t4 = x;
+  if(!(#t4 =={core::Object::==}{(core::Object) → core::bool} 1)) {
+  }
+  final dynamic #t5 = x;
+  if(!(#t5 == null)) {
+  }
+  final dynamic #t6 = x;
+  if(#t6{dynamic}.<(1)) {
+  }
+  final dynamic #t7 = x;
+  if(#t7{dynamic}.<=(1)) {
+  }
+  final dynamic #t8 = x;
+  if(#t8{dynamic}.>(1)) {
+  }
+  final dynamic #t9 = x;
+  if(#t9{dynamic}.>=(1)) {
   }
 }
+static method main() → dynamic {}

pkg/front_end/testcases/patterns/relational_inside_if_case.dart.weak.modular.expect

@@ -1,8 +1,34 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "dart:core" as core;
 
 static method test(dynamic x) → dynamic {
   final dynamic #t1 = x;
-  if(invalid-expression "Unimplemented RelationalMatcher.makeCondition") {
+  if(#t1 =={core::Object::==}{(core::Object) → core::bool} 1) {
+  }
+  final dynamic #t2 = x;
+  if(#t2 == null) {
+  }
+  final dynamic #t3 = x;
+  if(#t3 =={core::Object::==}{(core::Object) → core::bool} "foo".{core::String::length}{core::int}) {
+  }
+  final dynamic #t4 = x;
+  if(!(#t4 =={core::Object::==}{(core::Object) → core::bool} 1)) {
+  }
+  final dynamic #t5 = x;
+  if(!(#t5 == null)) {
+  }
+  final dynamic #t6 = x;
+  if(#t6{dynamic}.<(1)) {
+  }
+  final dynamic #t7 = x;
+  if(#t7{dynamic}.<=(1)) {
+  }
+  final dynamic #t8 = x;
+  if(#t8{dynamic}.>(1)) {
+  }
+  final dynamic #t9 = x;
+  if(#t9{dynamic}.>=(1)) {
   }
 }
+static method main() → dynamic {}

pkg/front_end/testcases/patterns/relational_inside_if_case.dart.weak.outline.expect

@@ -3,3 +3,5 @@ import self as self;
 
 static method test(dynamic x) → dynamic
   ;
+static method main() → dynamic
+  ;

pkg/front_end/testcases/patterns/relational_inside_if_case.dart.weak.transformed.expect

@@ -1,8 +1,39 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "dart:core" as core;
 
 static method test(dynamic x) → dynamic {
   final dynamic #t1 = x;
-  if(invalid-expression "Unimplemented RelationalMatcher.makeCondition") {
+  if(#t1 =={core::Object::==}{(core::Object) → core::bool} 1) {
+  }
+  final dynamic #t2 = x;
+  if(#t2 == null) {
+  }
+  final dynamic #t3 = x;
+  if(#t3 =={core::Object::==}{(core::Object) → core::bool} "foo".{core::String::length}{core::int}) {
+  }
+  final dynamic #t4 = x;
+  if(!(#t4 =={core::Object::==}{(core::Object) → core::bool} 1)) {
+  }
+  final dynamic #t5 = x;
+  if(!(#t5 == null)) {
+  }
+  final dynamic #t6 = x;
+  if(#t6{dynamic}.<(1)) {
+  }
+  final dynamic #t7 = x;
+  if(#t7{dynamic}.<=(1)) {
+  }
+  final dynamic #t8 = x;
+  if(#t8{dynamic}.>(1)) {
+  }
+  final dynamic #t9 = x;
+  if(#t9{dynamic}.>=(1)) {
   }
 }
+static method main() → dynamic {}
+
+
+Extra constant evaluation status:
+Evaluated: InstanceGet @ org-dartlang-testcase:///relational_inside_if_case.dart:8:23 -> IntConstant(3)
+Extra constant evaluation: evaluated: 30, effectively constant: 1