analyzer: Correct dead_code report range when syntax tree is rewritten.
The range at which to report dead code is controlled by
DeadCodeVerifier's _firstDeadNode field. But nodes can be rewritten
during resolution, in which case this AstNode gets lost. We just have
to update it as needed.
Fixes https://github.com/dart-lang/sdk/issues/55642
Change-Id: I57c341b64f90fbea0cf251d712eb8f18cb84b2d9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/400800
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
diff --git a/pkg/analyzer/lib/src/error/dead_code_verifier.dart b/pkg/analyzer/lib/src/error/dead_code_verifier.dart
index 8eb2f6d..69fba5f 100644
--- a/pkg/analyzer/lib/src/error/dead_code_verifier.dart
+++ b/pkg/analyzer/lib/src/error/dead_code_verifier.dart
@@ -337,6 +337,14 @@
_firstDeadNode = null;
}
+ /// Rewites [_firstDeadNode] if it is equal to [oldNode], as [oldNode] is
+ /// being rewritten into [newNode] in the syntax tree.
+ void maybeRewriteFirstDeadNode(AstNode oldNode, AstNode newNode) {
+ if (_firstDeadNode == oldNode) {
+ _firstDeadNode = newNode;
+ }
+ }
+
void tryStatementEnter(TryStatement node) {
var verifier = _CatchClausesVerifier(
_typeSystem,
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 19054fa..ed7fc3c 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -1389,6 +1389,7 @@
inferenceLogWriter?.recordExpressionRewrite(
oldExpression: oldNode, newExpression: newNode);
NodeReplacer.replace(oldNode, newNode, parent: parent);
+ nullSafetyDeadCodeVerifier.maybeRewriteFirstDeadNode(oldNode, newNode);
}
PatternResult<DartType> resolveAssignedVariablePattern({
diff --git a/pkg/analyzer/test/src/diagnostics/dead_code_test.dart b/pkg/analyzer/test/src/diagnostics/dead_code_test.dart
index 828cc0a..facc405 100644
--- a/pkg/analyzer/test/src/diagnostics/dead_code_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/dead_code_test.dart
@@ -17,6 +17,16 @@
@reflectiveTest
class DeadCodeTest extends PubPackageResolutionTest
with DeadCodeTestCases_Language212 {
+ test_deadBlock_conditionalElse_recordPropertyAccess() async {
+ await assertErrorsInCode(r'''
+void f(({int x, int y}) p) {
+ true ? p.x : p.y;
+}
+''', [
+ error(WarningCode.DEAD_CODE, 44, 3),
+ ]);
+ }
+
test_deadOperandLHS_or_recordPropertyAccess() async {
await assertErrorsInCode(r'''
void f(({bool b, }) r) {
@@ -402,7 +412,7 @@
]);
}
- test_deadBlock_conditionalIf() async {
+ test_deadBlock_conditionalThen() async {
await assertErrorsInCode(r'''
f() {
false ? 1 : 2;
@@ -412,7 +422,7 @@
]);
}
- test_deadBlock_conditionalIf_debugConst() async {
+ test_deadBlock_conditionalThen_debugConst() async {
await assertNoErrorsInCode(r'''
const bool DEBUG = false;
f() {
@@ -421,7 +431,7 @@
''');
}
- test_deadBlock_conditionalIf_nested() async {
+ test_deadBlock_conditionalThen_nested() async {
// Test that a dead then-statement can't generate additional violations.
await assertErrorsInCode(r'''
f() {
