[Expression compiler] fix pattern evaluation and scope tests

- Update pattern scope tests after CFE switch improvements.
- Fix incorrect end offset detection in expression compiler.
  Account for synthetic variables that can have offsets from
  later code (i.e. created for hoisting).

Related: #51554

Closes: #51825
Change-Id: I07cd319f8996acae2dada96ba6e43eac9e04fbb6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/290706
Reviewed-by: Nicholas Shahan <[email protected]>
Commit-Queue: Anna Gringauze <[email protected]>
Reviewed-by: Mark Zhou <[email protected]>

Author: Anna Gringauze

pkg/dev_compiler/lib/src/kernel/expression_compiler.dart

@@ -205,14 +205,16 @@ class FileEndOffsetCalculator extends Visitor<int?> with VisitorNullMixin<int> {
 
   final int _startOffset;
   final TreeNode _root;
+  final TreeNode _original;
 
   int _endOffset = noOffset;
 
   /// Create calculator for a scoping node with no .fileEndOffset.
   ///
   /// [_root] is the parent of the scoping node.
   /// [_startOffset] is the start offset of the scoping node.
-  FileEndOffsetCalculator._(this._root, this._startOffset);
+  FileEndOffsetCalculator._(this._root, this._original)
+      : _startOffset = _original.fileOffset;
 
   /// Calculate file end offset for a scoping node.
   ///
@@ -231,7 +233,7 @@ class FileEndOffsetCalculator extends Visitor<int?> with VisitorNullMixin<int> {
   /// If none found, return [noOffset].
   static int calculateEndOffset(TreeNode node) {
     for (var n = node.parent; n != null; n = n.parent) {
-      var calculator = FileEndOffsetCalculator._(n, node.fileOffset);
+      var calculator = FileEndOffsetCalculator._(n, node);
       var offset = n.accept(calculator);
       if (offset != noOffset) return offset!;
     }
@@ -240,12 +242,17 @@ class FileEndOffsetCalculator extends Visitor<int?> with VisitorNullMixin<int> {
 
   @override
   int defaultTreeNode(TreeNode node) {
+    if (node == _original) return _endOffset;
     if (node == _root) {
       node.visitChildren(this);
       if (_endOffset != noOffset) return _endOffset;
       return _endOffsetForNode(node);
     }
-    if (_endOffset == noOffset && node.fileOffset > _startOffset) {
+    // Skip synthesized variables as they could have offsets
+    // from later code (in case they are hoisted, for example).
+    if ((node is! VariableDeclaration || !node.isSynthesized) &&
+        _endOffset == noOffset &&
+        node.fileOffset > _startOffset) {
       _endOffset = node.fileOffset;
     }
     return _endOffset;

pkg/dev_compiler/test/expression_compiler/expression_compiler_e2e_amd_sound_test.dart

@@ -10,6 +10,8 @@ import 'expression_compiler_e2e_shared.dart';
 import 'expression_compiler_e2e_suite.dart';
 
 void main() async {
+  // Set to `true` for debug output.
+  final debug = false;
   var driver = await TestDriver.init();
 
   group('(Sound null safety)', () {
@@ -22,6 +24,7 @@ void main() async {
           soundNullSafety: true,
           legacyCode: false,
           moduleFormat: ModuleFormat.amd);
+      setup.options.verbose = debug;
       runAgnosticSharedTests(setup, driver);
       runNullSafeSharedTests(setup, driver);
     });

pkg/dev_compiler/test/expression_compiler/expression_compiler_e2e_shared.dart

@@ -283,38 +283,20 @@ void runNullSafeSharedTests(SetupCompilerOptions setup, TestDriver driver) {
           expectedResult: '0');
     });
 
-    // TODO(annagrin): Remove renamed variables here and below after
-    // const evaluator stops renaming variables used in cases.
-    //
-    // Issue: https://github.com/dart-lang/sdk/issues/51554
     test('first case scope', () async {
-      await driver.checkScope(breakpointId: 'bp1', expectedScope: {
-        'a': '1',
-        'b': '2',
-        r'a$351': r'a$351',
-        r'b$351': r'b$351',
-        'obj': 'obj'
-      });
+      await driver.checkScope(
+          breakpointId: 'bp1',
+          expectedScope: {'a': '1', 'b': '2', 'obj': 'obj'});
     });
 
     test('second case scope', () async {
-      await driver.checkScope(breakpointId: 'bp2', expectedScope: {
-        'a': '10',
-        'b': '10',
-        r'a$351': '10',
-        r'b$351': '\'20\'',
-        'obj': 'obj'
-      });
+      await driver.checkScope(
+          breakpointId: 'bp2',
+          expectedScope: {'a': '10', 'b': '\'20\'', 'obj': 'obj'});
     });
 
     test('default case scope', () async {
-      await driver.checkScope(breakpointId: 'bp3', expectedScope: {
-        'a': 'a',
-        'b': 'b',
-        r'a$351': r'a$351',
-        r'b$351': r'b$351',
-        'obj': '0'
-      });
+      await driver.checkScope(breakpointId: 'bp3', expectedScope: {'obj': '0'});
     });
 
     test('result scope', () async {