Flow analysis: Use blocks internally in mini_ast representation.
For convenience in creating tests, the public mini_ast methods for
creating constructs like loops, try/catch, etc. accept lists of
statements as an argument where technically the language would expect
a single statement. This CL changes the internal representation so
that each of these statement lists is converted into a single
statement by wrapping it in a block.
This makes the mini_ast representation more closely match the
representation used internally by the analyzer and CFE.
Change-Id: If2bf8a1cde694206b91b57c5907806b1965d4d99
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/193880
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/_fe_analyzer_shared/test/mini_ast.dart b/pkg/_fe_analyzer_shared/test/mini_ast.dart
index 77f2cf0..9e1ca0a 100644
--- a/pkg/_fe_analyzer_shared/test/mini_ast.dart
+++ b/pkg/_fe_analyzer_shared/test/mini_ast.dart
@@ -37,7 +37,7 @@
new _Break(branchTargetPlaceholder);
SwitchCase case_(List<Statement> body, {bool hasLabel = false}) =>
- SwitchCase._(hasLabel, body);
+ SwitchCase._(hasLabel, new _Block(body));
/// Creates a pseudo-statement whose function is to verify that flow analysis
/// considers [variable]'s assigned state to be [expectedAssignedState].
@@ -79,7 +79,7 @@
new _Declare(variable, initializer, isFinal, isLate);
Statement do_(List<Statement> body, Expression condition) =>
- _Do(body, condition);
+ _Do(block(body), condition);
/// Creates a pseudo-expression having type [typeStr] that otherwise has no
/// effect on flow analysis.
@@ -92,7 +92,7 @@
Statement for_(Statement? initializer, Expression? condition,
Expression? updater, List<Statement> body,
{bool forCollection = false}) =>
- new _For(initializer, condition, updater, body, forCollection);
+ new _For(initializer, condition, updater, block(body), forCollection);
/// Creates a "for each" statement where the identifier being assigned to by the
/// iteration is not a local variable.
@@ -103,7 +103,7 @@
/// for (x in iterable) { ... }
/// }
Statement forEachWithNonVariable(Expression iterable, List<Statement> body) =>
- new _ForEach(null, iterable, body, false);
+ new _ForEach(null, iterable, block(body), false);
/// Creates a "for each" statement where the identifier being assigned to by the
/// iteration is a variable that is being declared by the "for each" statement.
@@ -116,7 +116,7 @@
Var variable, Expression iterable, List<Statement> body) {
// ignore: unnecessary_null_comparison
assert(variable != null);
- return new _ForEach(variable, iterable, body, true);
+ return new _ForEach(variable, iterable, block(body), true);
}
/// Creates a "for each" statement where the identifier being assigned to by the
@@ -131,7 +131,7 @@
Var variable, Expression iterable, List<Statement> body) {
// ignore: unnecessary_null_comparison
assert(variable != null);
- return new _ForEach(variable, iterable, body, false);
+ return new _ForEach(variable, iterable, block(body), false);
}
/// Creates a [Statement] that, when analyzed, will cause [callback] to be
@@ -142,7 +142,7 @@
Statement if_(Expression condition, List<Statement> ifTrue,
[List<Statement>? ifFalse]) =>
- new _If(condition, ifTrue, ifFalse);
+ new _If(condition, block(ifTrue), ifFalse == null ? null : block(ifFalse));
Statement implicitThis_whyNotPromoted(String staticType,
void Function(Map<Type, NonPromotionReason>) callback) =>
@@ -150,7 +150,7 @@
Statement labeled(Statement body) => new _LabeledStatement(body);
-Statement localFunction(List<Statement> body) => _LocalFunction(body);
+Statement localFunction(List<Statement> body) => _LocalFunction(block(body));
Statement return_() => new _Return();
@@ -163,10 +163,11 @@
Expression throw_(Expression operand) => new _Throw(operand);
-TryBuilder try_(List<Statement> body) => new _TryStatement(body, [], null);
+TryBuilder try_(List<Statement> body) =>
+ new _TryStatement(block(body), [], null);
Statement while_(Expression condition, List<Statement> body) =>
- new _While(condition, body);
+ new _While(condition, block(body));
/// Placeholder used by [branchTarget] to tie `break` and `continue` statements
/// to their branch targets.
@@ -481,13 +482,14 @@
/// they contain.
void run(List<Statement> statements) {
var assignedVariables = AssignedVariables<Node, Var>();
- statements._preVisit(assignedVariables);
+ var b = block(statements);
+ b._preVisit(assignedVariables);
var flow = legacy
? FlowAnalysis<Node, Statement, Expression, Var, Type>.legacy(
this, assignedVariables)
: FlowAnalysis<Node, Statement, Expression, Var, Type>(
this, assignedVariables);
- statements._visit(this, flow);
+ b._visit(this, flow);
flow.finish();
}
@@ -601,12 +603,15 @@
/// to create instances of this class.
class SwitchCase implements _Visitable<void> {
final bool _hasLabel;
- final List<Statement> _body;
+ final _Block _body;
SwitchCase._(this._hasLabel, this._body);
- String toString() =>
- [if (_hasLabel) '<label>:', 'case <value>:', ..._body].join(' ');
+ String toString() => [
+ if (_hasLabel) '<label>:',
+ 'case <value>:',
+ ..._body.statements
+ ].join(' ');
void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
_body._preVisit(assignedVariables);
@@ -713,13 +718,17 @@
@override
void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
- statements._preVisit(assignedVariables);
+ for (var statement in statements) {
+ statement._preVisit(assignedVariables);
+ }
}
@override
void _visit(
Harness h, FlowAnalysis<Node, Statement, Expression, Var, Type> flow) {
- statements._visit(h, flow);
+ for (var statement in statements) {
+ statement._visit(h, flow);
+ }
}
}
@@ -765,7 +774,7 @@
/// Representation of a single catch clause in a try/catch statement. Use
/// [catch_] to create instances of this class.
class _CatchClause implements _Visitable<void> {
- final List<Statement> _body;
+ final Statement _body;
final Var? _exception;
final Var? _stackTrace;
@@ -780,7 +789,7 @@
} else {
initialPart = 'on ...';
}
- return '$initialPart ${block(_body)}';
+ return '$initialPart $_body';
}
void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
@@ -973,13 +982,13 @@
}
class _Do extends Statement {
- final List<Statement> body;
+ final Statement body;
final Expression condition;
_Do(this.body, this.condition) : super._();
@override
- String toString() => 'do ${block(body)} while ($condition);';
+ String toString() => 'do $body while ($condition);';
@override
void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
@@ -1051,7 +1060,7 @@
final Statement? initializer;
final Expression? condition;
final Expression? updater;
- final List<Statement> body;
+ final Statement body;
final bool forCollection;
_For(this.initializer, this.condition, this.updater, this.body,
@@ -1074,7 +1083,7 @@
if (updater != null) {
buffer.write(' $updater');
}
- buffer.write(') ${block(body)}');
+ buffer.write(') $body');
return buffer.toString();
}
@@ -1105,7 +1114,7 @@
class _ForEach extends Statement {
final Var? variable;
final Expression iterable;
- final List<Statement> body;
+ final Statement body;
final bool declaresVariable;
_ForEach(this.variable, this.iterable, this.body, this.declaresVariable)
@@ -1121,7 +1130,7 @@
} else {
declarationPart = variable!.name;
}
- return 'for ($declarationPart in $iterable) ${block(body)}';
+ return 'for ($declarationPart in $iterable) $body';
}
@override
@@ -1192,15 +1201,14 @@
class _If extends Statement {
final Expression condition;
- final List<Statement> ifTrue;
- final List<Statement>? ifFalse;
+ final Statement ifTrue;
+ final Statement? ifFalse;
_If(this.condition, this.ifTrue, this.ifFalse) : super._();
@override
String toString() =>
- 'if ($condition) ${block(ifTrue)}' +
- (ifFalse == null ? '' : 'else ${block(ifFalse!)}');
+ 'if ($condition) $ifTrue' + (ifFalse == null ? '' : 'else $ifFalse');
@override
void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
@@ -1299,12 +1307,12 @@
}
class _LocalFunction extends Statement {
- final List<Statement> body;
+ final Statement body;
_LocalFunction(this.body) : super._();
@override
- String toString() => '() ${block(body)}';
+ String toString() => '() $body';
@override
void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
@@ -1561,7 +1569,9 @@
void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
expression._preVisit(assignedVariables);
assignedVariables.beginNode();
- cases._preVisit(assignedVariables);
+ for (var case_ in cases) {
+ case_._preVisit(assignedVariables);
+ }
assignedVariables.endNode(this);
}
@@ -1572,7 +1582,9 @@
flow.switchStatement_expressionEnd(this);
var oldSwitch = h._currentSwitch;
h._currentSwitch = this;
- cases._visit(h, flow);
+ for (var case_ in cases) {
+ case_._visit(h, flow);
+ }
h._currentSwitch = oldSwitch;
flow.switchStatement_end(isExhaustive);
}
@@ -1635,9 +1647,9 @@
}
class _TryStatement extends TryStatement {
- final List<Statement> _body;
+ final Statement _body;
final List<_CatchClause> _catches;
- final List<Statement>? _finally;
+ final Statement? _finally;
final _bodyNode = Node._();
_TryStatement(this._body, this._catches, this._finally) : super._();
@@ -1646,14 +1658,14 @@
TryStatement catch_(
{Var? exception, Var? stackTrace, required List<Statement> body}) {
assert(_finally == null, 'catch after finally');
- return _TryStatement(
- _body, [..._catches, _CatchClause(body, exception, stackTrace)], null);
+ return _TryStatement(_body,
+ [..._catches, _CatchClause(block(body), exception, stackTrace)], null);
}
@override
Statement finally_(List<Statement> statements) {
assert(_finally == null, 'multiple finally clauses');
- return _TryStatement(_body, _catches, statements);
+ return _TryStatement(_body, _catches, block(statements));
}
@override
@@ -1666,7 +1678,9 @@
}
_body._preVisit(assignedVariables);
assignedVariables.endNode(_bodyNode);
- _catches._preVisit(assignedVariables);
+ for (var catch_ in _catches) {
+ catch_._preVisit(assignedVariables);
+ }
if (_finally != null) {
if (_catches.isNotEmpty) {
assignedVariables.endNode(this);
@@ -1687,7 +1701,9 @@
_body._visit(h, flow);
if (_catches.isNotEmpty) {
flow.tryCatchStatement_bodyEnd(_bodyNode);
- _catches._visit(h, flow);
+ for (var catch_ in _catches) {
+ catch_._visit(h, flow);
+ }
flow.tryCatchStatement_end();
}
if (_finally != null) {
@@ -1744,12 +1760,12 @@
class _While extends Statement {
final Expression condition;
- final List<Statement> body;
+ final Statement body;
_While(this.condition, this.body) : super._();
@override
- String toString() => 'while ($condition) ${block(body)}';
+ String toString() => 'while ($condition) $body';
@override
void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
@@ -1892,18 +1908,3 @@
return type;
}
}
-
-extension on List<_Visitable<void>> {
- void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
- for (var element in this) {
- element._preVisit(assignedVariables);
- }
- }
-
- void _visit(
- Harness h, FlowAnalysis<Node, Statement, Expression, Var, Type> flow) {
- for (var element in this) {
- element._visit(h, flow);
- }
- }
-}
