Improvements for flow analysis.
Support for 'IfNull' expression.
Support for 'rethrow'.
Tests for definite assignment and assignment expressions.
Change-Id: I053d27ca05e4ccaccc6a9fc7e10a481cd481ab21
Reviewed-on: https://dart-review.googlesource.com/c/90102
Reviewed-by: Paul Berry <paulberry@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analyzer/lib/src/dart/resolver/flow_analysis.dart b/pkg/analyzer/lib/src/dart/resolver/flow_analysis.dart
index e33f899..46a2025 100644
--- a/pkg/analyzer/lib/src/dart/resolver/flow_analysis.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/flow_analysis.dart
@@ -215,6 +215,15 @@
_current = _State.identity;
}
+ void ifNullExpression_end() {
+ var afterLeft = _stack.removeLast();
+ _current = _current.combine(typeSystem, afterLeft);
+ }
+
+ void ifNullExpression_rightBegin() {
+ _stack.add(_current); // afterLeft
+ }
+
void ifStatement_elseBegin() {
var afterThen = _current;
var falseCondition = _stack.removeLast();
diff --git a/pkg/analyzer/test/src/dart/resolution/flow_analysis_test.dart b/pkg/analyzer/test/src/dart/resolution/flow_analysis_test.dart
index 9710109..9114973 100644
--- a/pkg/analyzer/test/src/dart/resolution/flow_analysis_test.dart
+++ b/pkg/analyzer/test/src/dart/resolution/flow_analysis_test.dart
@@ -38,6 +38,99 @@
expect(readBeforeWritten, unorderedEquals(expected));
}
+ test_assignment_leftExpression() async {
+ await trackCode(r'''
+void f() {
+ List<int> v;
+ v[0] = (v = [1, 2])[1];
+ v;
+}
+''');
+ assertReadBeforeWritten('v');
+ }
+
+ test_assignment_leftLocal_compound() async {
+ await trackCode(r'''
+void f() {
+ int v;
+ v += 1;
+}
+''');
+ assertReadBeforeWritten('v');
+ }
+
+ test_assignment_leftLocal_compound_assignInRight() async {
+ await trackCode(r'''
+void f() {
+ int v;
+ v += (v = v);
+}
+''');
+ assertReadBeforeWritten('v');
+ }
+
+ test_assignment_leftLocal_pure_eq() async {
+ await trackCode(r'''
+void f() {
+ int v;
+ v = 0;
+}
+''');
+ assertReadBeforeWritten();
+ }
+
+ test_assignment_leftLocal_pure_eq_self() async {
+ await trackCode(r'''
+void f() {
+ int v;
+ v = v;
+}
+''');
+ assertReadBeforeWritten('v');
+ }
+
+ test_assignment_leftLocal_pure_questionEq() async {
+ await trackCode(r'''
+void f() {
+ int v;
+ v ??= 0;
+}
+''');
+ assertReadBeforeWritten('v');
+ }
+
+ test_assignment_leftLocal_pure_questionEq_self() async {
+ await trackCode(r'''
+void f() {
+ int v;
+ v ??= v;
+}
+''');
+ assertReadBeforeWritten('v');
+ }
+
+ test_binaryExpression_ifNull_left() async {
+ await trackCode(r'''
+void f() {
+ int v;
+ (v = 0) ?? 0;
+ v;
+}
+''');
+ assertReadBeforeWritten();
+ }
+
+ test_binaryExpression_ifNull_right() async {
+ await trackCode(r'''
+void f(int a) {
+ int v;
+ a ?? (v = 0);
+ v;
+}
+''');
+ assertReadBeforeWritten('v');
+ }
+
test_binaryExpression_logicalAnd_left() async {
await trackCode(r'''
main(bool c) {
@@ -137,6 +230,17 @@
assertReadBeforeWritten('v');
}
+ test_conditionalExpression_condition() async {
+ await trackCode(r'''
+main() {
+ int v;
+ (v = 0) >= 0 ? 1 : 2;
+ v;
+}
+''');
+ assertReadBeforeWritten();
+ }
+
test_doWhile_break_afterAssignment() async {
await trackCode(r'''
void f(bool b) {
@@ -894,6 +998,21 @@
assertReadBeforeWritten();
}
+ test_tryCatch_body_catchRethrow() async {
+ await trackCode(r'''
+void f() {
+ int v;
+ try {
+ v = 0;
+ } catch (_) {
+ rethrow;
+ }
+ v;
+}
+''');
+ assertReadBeforeWritten();
+ }
+
test_tryCatch_catch() async {
await trackCode(r'''
void f() {
@@ -1212,9 +1331,33 @@
assertNotPromoted('x; // 1');
}
- test_conditional() async {
+ test_binaryExpression_ifNull() async {
await trackCode(r'''
-f(bool b, Object x) {
+void f(Object x) {
+ ((x is num) || (throw 1)) ?? ((x is int) || (throw 2));
+ x; // 1
+}
+''');
+ assertPromoted('x; // 1', 'num');
+ }
+
+ test_binaryExpression_ifNull_rightUnPromote() async {
+ await trackCode(r'''
+void f(Object x, Object y, Object z) {
+ if (x is int) {
+ x; // 1
+ y ?? (x = z);
+ x; // 2
+ }
+}
+''');
+ assertPromoted('x; // 1', 'int');
+ assertNotPromoted('x; // 2');
+ }
+
+ test_conditional_both() async {
+ await trackCode(r'''
+void f(bool b, Object x) {
b ? ((x is num) || (throw 1)) : ((x is int) || (throw 2));
x; // 1
}
@@ -1222,6 +1365,26 @@
assertPromoted('x; // 1', 'num');
}
+ test_conditional_else() async {
+ await trackCode(r'''
+void f(bool b, Object x) {
+ b ? 0 : ((x is int) || (throw 2));
+ x; // 1
+}
+''');
+ assertNotPromoted('x; // 1');
+ }
+
+ test_conditional_then() async {
+ await trackCode(r'''
+void f(bool b, Object x) {
+ b ? ((x is num) || (throw 1)) : 0;
+ x; // 1
+}
+''');
+ assertNotPromoted('x; // 1');
+ }
+
test_do_condition_isNotType() async {
await trackCode(r'''
void f(Object x) {
@@ -1568,6 +1731,18 @@
assertNotPromoted('v; // 3');
}
+ test_if_then_isNotType_return() async {
+ await trackCode(r'''
+void f(bool b, Object x) {
+ if (b) {
+ if (x is! String) return;
+ }
+ x; // 1
+}
+''');
+ assertNotPromoted('x; // 1');
+ }
+
test_logicalOr_throw() async {
await trackCode(r'''
main(v) {
@@ -1688,6 +1863,26 @@
assertPromoted('x; // 3', 'String');
}
+ test_try_isNotType_exit_body_catchRethrow() async {
+ await trackCode(r'''
+void f(Object x) {
+ try {
+ if (x is! String) return;
+ x; // 1
+ } catch (_) {
+ x; // 2
+ rethrow;
+ }
+ x; // 3
+}
+
+void g() {}
+''');
+ assertPromoted('x; // 1', 'String');
+ assertNotPromoted('x; // 2');
+ assertPromoted('x; // 3', 'String');
+ }
+
test_try_isNotType_exit_catch() async {
await trackCode(r'''
void f(Object x) {
@@ -1950,26 +2145,17 @@
right.accept(this);
flow.logicalOr_end(node);
+ } else if (operator == TokenType.QUESTION_QUESTION) {
+ left.accept(this);
+
+ flow.ifNullExpression_rightBegin();
+ right.accept(this);
+
+ flow.ifNullExpression_end();
} else {
left.accept(this);
right.accept(this);
}
-
-// var isLogical = operator == TokenType.AMPERSAND_AMPERSAND ||
-// operator == TokenType.BAR_BAR ||
-// operator == TokenType.QUESTION_QUESTION;
-//
-// left.accept(this);
-//
-// if (isLogical) {
-// tracker.beginBinaryExpressionLogicalRight();
-// }
-//
-// right.accept(this);
-//
-// if (isLogical) {
-// tracker.endBinaryExpressionLogicalRight();
-// }
}
@override
@@ -2133,6 +2319,12 @@
}
@override
+ void visitRethrowExpression(RethrowExpression node) {
+ super.visitRethrowExpression(node);
+ flow.handleExit();
+ }
+
+ @override
void visitReturnStatement(ReturnStatement node) {
super.visitReturnStatement(node);
flow.handleExit();
