Refactor for statement parsing
This CL introduces 2 new parser listener events
in preparation for parsing for control flow structures
in literal lists, sets, and maps.
Change-Id: I230f36cded714a13e4badb401fe5b5906c93a2da
Reviewed-on: https://dart-review.googlesource.com/c/91144
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Dan Rubel <danrubel@google.com>
diff --git a/pkg/analyzer/lib/src/fasta/ast_builder.dart b/pkg/analyzer/lib/src/fasta/ast_builder.dart
index 31b8756..79bdc7e 100644
--- a/pkg/analyzer/lib/src/fasta/ast_builder.dart
+++ b/pkg/analyzer/lib/src/fasta/ast_builder.dart
@@ -865,14 +865,29 @@
}
@override
- void endForStatement(Token forKeyword, Token leftParen, Token leftSeparator,
- int updateExpressionCount, Token endToken) {
+ void handleForLoopParts(Token forKeyword, Token leftParen,
+ Token leftSeparator, int updateExpressionCount) {
assert(optional('for', forKeyword));
assert(optional('(', leftParen));
assert(optional(';', leftSeparator));
- debugEvent("ForStatement");
+ assert(updateExpressionCount >= 0);
+ push(forKeyword);
+ push(leftParen);
+ push(leftSeparator);
+ push(updateExpressionCount);
+ }
+
+ @override
+ void endForStatement(Token endToken) {
+ debugEvent("ForStatement");
Statement body = pop();
+
+ int updateExpressionCount = pop();
+ Token leftSeparator = pop();
+ Token leftParen = pop();
+ Token forKeyword = pop();
+
List<Expression> updates = popTypedList(updateExpressionCount);
Statement conditionStatement = pop();
Object initializerPart = pop();
@@ -1276,15 +1291,30 @@
}
@override
- void endForIn(Token awaitToken, Token forToken, Token leftParenthesis,
- Token inKeyword, Token endToken) {
+ void handleForInLoopParts(Token awaitToken, Token forToken,
+ Token leftParenthesis, Token inKeyword) {
assert(optionalOrNull('await', awaitToken));
assert(optional('for', forToken));
assert(optional('(', leftParenthesis));
assert(optional('in', inKeyword) || optional(':', inKeyword));
+
+ push(awaitToken ?? NullValue.AwaitToken);
+ push(forToken);
+ push(leftParenthesis);
+ push(inKeyword);
+ }
+
+ @override
+ void endForIn(Token endToken) {
debugEvent("ForInExpression");
Statement body = pop();
+
+ Token inKeyword = pop();
+ Token leftParenthesis = pop();
+ Token forToken = pop();
+ Token awaitToken = pop(NullValue.AwaitToken);
+
Expression iterator = pop();
Object variableOrDeclaration = pop();
if (variableOrDeclaration is VariableDeclarationStatement) {
diff --git a/pkg/analyzer/test/generated/parser_fasta_listener.dart b/pkg/analyzer/test/generated/parser_fasta_listener.dart
index 5a2a061..8fea9c5 100644
--- a/pkg/analyzer/test/generated/parser_fasta_listener.dart
+++ b/pkg/analyzer/test/generated/parser_fasta_listener.dart
@@ -704,10 +704,9 @@
}
@override
- void endForIn(Token awaitToken, Token forToken, Token leftParen,
- Token inKeyword, Token endToken) {
+ void endForIn(Token endToken) {
end('ForStatement');
- super.endForIn(awaitToken, forToken, leftParen, inKeyword, endToken);
+ super.endForIn(endToken);
}
@override
@@ -723,11 +722,9 @@
}
@override
- void endForStatement(Token forKeyword, Token leftParen, Token leftSeparator,
- int updateExpressionCount, Token endToken) {
+ void endForStatement(Token endToken) {
end('ForStatement');
- super.endForStatement(
- forKeyword, leftParen, leftSeparator, updateExpressionCount, endToken);
+ super.endForStatement(endToken);
}
@override
diff --git a/pkg/analyzer/test/src/fasta/recovery/partial_code/forEach_statement_test.dart b/pkg/analyzer/test/src/fasta/recovery/partial_code/forEach_statement_test.dart
index 247cc34..0f15628e5 100644
--- a/pkg/analyzer/test/src/fasta/recovery/partial_code/forEach_statement_test.dart
+++ b/pkg/analyzer/test/src/fasta/recovery/partial_code/forEach_statement_test.dart
@@ -63,6 +63,7 @@
ParserErrorCode.MISSING_IDENTIFIER,
ParserErrorCode.MISSING_IDENTIFIER,
ParserErrorCode.MISSING_IDENTIFIER,
+ ParserErrorCode.MISSING_IDENTIFIER,
ParserErrorCode.EXPECTED_TOKEN,
ParserErrorCode.EXPECTED_TOKEN
],
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index ace876e..49b3d21 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -2241,10 +2241,24 @@
}
@override
- void endForStatement(Token forKeyword, Token leftParen, Token leftSeparator,
- int updateExpressionCount, Token endToken) {
+ void handleForLoopParts(Token forKeyword, Token leftParen,
+ Token leftSeparator, int updateExpressionCount) {
+ push(forKeyword);
+ push(leftParen);
+ push(leftSeparator);
+ push(updateExpressionCount);
+ }
+
+ @override
+ void endForStatement(Token endToken) {
debugEvent("ForStatement");
Statement body = popStatement();
+
+ int updateExpressionCount = pop();
+ Token leftSeparator = pop();
+ Token leftParen = pop();
+ Token forKeyword = pop();
+
List<Expression> updates = popListForEffect(updateExpressionCount);
Statement conditionStatement = popStatement();
Object variableOrExpression = pop();
@@ -3829,10 +3843,22 @@
}
@override
- void endForIn(Token awaitToken, Token forToken, Token leftParenthesis,
- Token inKeyword, Token endToken) {
+ void handleForInLoopParts(Token awaitToken, Token forToken,
+ Token leftParenthesis, Token inKeyword) {
+ push(awaitToken ?? NullValue.AwaitToken);
+ push(forToken);
+ push(inKeyword);
+ }
+
+ @override
+ void endForIn(Token endToken) {
debugEvent("ForIn");
Statement body = popStatement();
+
+ Token inKeyword = pop();
+ Token forToken = pop();
+ Token awaitToken = pop(NullValue.AwaitToken);
+
Expression expression = popForValue();
Object lvalue = pop();
exitLocalScope();
diff --git a/pkg/front_end/lib/src/fasta/parser/forwarding_listener.dart b/pkg/front_end/lib/src/fasta/parser/forwarding_listener.dart
index b909283..decbb5a 100644
--- a/pkg/front_end/lib/src/fasta/parser/forwarding_listener.dart
+++ b/pkg/front_end/lib/src/fasta/parser/forwarding_listener.dart
@@ -564,9 +564,8 @@
}
@override
- void endForIn(Token awaitToken, Token forToken, Token leftParen,
- Token inKeyword, Token endToken) {
- listener?.endForIn(awaitToken, forToken, leftParen, inKeyword, endToken);
+ void endForIn(Token endToken) {
+ listener?.endForIn(endToken);
}
@override
@@ -580,10 +579,8 @@
}
@override
- void endForStatement(Token forKeyword, Token leftParen, Token leftSeparator,
- int updateExpressionCount, Token endToken) {
- listener?.endForStatement(
- forKeyword, leftParen, leftSeparator, updateExpressionCount, endToken);
+ void endForStatement(Token endToken) {
+ listener?.endForStatement(endToken);
}
@override
@@ -1220,6 +1217,20 @@
}
@override
+ void handleForInLoopParts(Token awaitToken, Token forToken,
+ Token leftParenthesis, Token inKeyword) {
+ listener?.handleForInLoopParts(
+ awaitToken, forToken, leftParenthesis, inKeyword);
+ }
+
+ @override
+ void handleForLoopParts(Token forKeyword, Token leftParen,
+ Token leftSeparator, int updateExpressionCount) {
+ listener?.handleForLoopParts(
+ forKeyword, leftParen, leftSeparator, updateExpressionCount);
+ }
+
+ @override
void handleNoFieldInitializer(Token token) {
listener?.handleNoFieldInitializer(token);
}
diff --git a/pkg/front_end/lib/src/fasta/parser/listener.dart b/pkg/front_end/lib/src/fasta/parser/listener.dart
index 0345607..7c6fb85 100644
--- a/pkg/front_end/lib/src/fasta/parser/listener.dart
+++ b/pkg/front_end/lib/src/fasta/parser/listener.dart
@@ -323,8 +323,13 @@
/// [endForStatement] or [endForIn].
void beginForStatement(Token token) {}
- void endForStatement(Token forKeyword, Token leftParen, Token leftSeparator,
- int updateExpressionCount, Token endToken) {
+ /// Marks the end of parsing the control structure of a for statement
+ /// or for control flow entry up to and including the closing parenthesis.
+ /// `for` `(` initialization `;` condition `;` updaters `)`
+ void handleForLoopParts(Token forKeyword, Token leftParen,
+ Token leftSeparator, int updateExpressionCount) {}
+
+ void endForStatement(Token endToken) {
logEvent("ForStatement");
}
@@ -334,9 +339,14 @@
logEvent("ForStatementBody");
}
+ /// Marks the end of parsing the control structure of a for-in statement
+ /// or for control flow entry up to and including the closing parenthesis.
+ /// `for` `(` (type)? identifier `in` iterator `)`
+ void handleForInLoopParts(Token awaitToken, Token forToken,
+ Token leftParenthesis, Token inKeyword) {}
+
// One of the two possible corresponding end events for [beginForStatement].
- void endForIn(Token awaitToken, Token forToken, Token leftParenthesis,
- Token inKeyword, Token endToken) {
+ void endForIn(Token endToken) {
logEvent("ForIn");
}
diff --git a/pkg/front_end/lib/src/fasta/parser/parser.dart b/pkg/front_end/lib/src/fasta/parser/parser.dart
index 6d2a937c..cd79c96 100644
--- a/pkg/front_end/lib/src/fasta/parser/parser.dart
+++ b/pkg/front_end/lib/src/fasta/parser/parser.dart
@@ -5296,10 +5296,11 @@
/// 'await'? 'for' '(' forLoopParts ')' statement
/// ;
///
- /// forLoopParts:
- /// forInitializerStatement expression? ';' expressionList? |
- /// declaredIdentifier 'in' expression |
- /// identifier 'in' expression
+ /// forLoopParts:
+ /// localVariableDeclaration ';' expression? ';' expressionList?
+ /// | expression? ';' expression? ';' expressionList?
+ /// | localVariableDeclaration 'in' expression
+ /// | identifier 'in' expression
/// ;
///
/// forInitializerStatement:
@@ -5308,20 +5309,35 @@
/// ;
/// ```
Token parseForStatement(Token token, Token awaitToken) {
- Token forKeyword = token = token.next;
+ Token forToken = token = token.next;
assert(awaitToken == null || optional('await', awaitToken));
assert(optional('for', token));
- listener.beginForStatement(forKeyword);
+ listener.beginForStatement(forToken);
- Token leftParenthesis = forKeyword.next;
+ token = parseForLoopPartsStart(awaitToken, forToken);
+ Token identifier = token.next;
+ token = parseForLoopPartsMid(token, forToken);
+ if (looksLikeForInLoopParts(awaitToken, token.next)) {
+ // Process `for ( ... in ... )`
+ return parseForInRest(token, awaitToken, forToken, identifier);
+ } else {
+ // Process `for ( ... ; ... ; ... )`
+ return parseForRest(awaitToken, token, forToken);
+ }
+ }
+
+ /// Parse the start of a for loop control structure
+ /// from the open parenthesis up to but not including the identifier.
+ Token parseForLoopPartsStart(Token awaitToken, Token forToken) {
+ Token leftParenthesis = forToken.next;
if (!optional('(', leftParenthesis)) {
// Recovery
reportRecoverableError(
leftParenthesis, fasta.templateExpectedButGot.withArguments('('));
int offset = leftParenthesis.offset;
- BeginToken openParen =
- token.setNext(new SyntheticBeginToken(TokenType.OPEN_PAREN, offset));
+ BeginToken openParen = forToken
+ .setNext(new SyntheticBeginToken(TokenType.OPEN_PAREN, offset));
Token loopPart;
if (awaitToken != null) {
@@ -5349,18 +5365,18 @@
leftParenthesis = openParen;
}
- token = leftParenthesis;
// Pass `true` so that the [parseExpressionStatementOrDeclaration] only
// parses the metadata, modifiers, and type of a local variable
// declaration if it exists. This enables capturing [beforeIdentifier]
// for later error reporting.
- token = parseExpressionStatementOrDeclaration(token, true);
- Token beforeIdentifier = token;
+ return parseExpressionStatementOrDeclaration(forToken.next, true);
+ }
- // Parse the remainder of the local variable declaration
- // or an expression if no local variable declaration was found.
- if (token != leftParenthesis) {
+ /// Parse the remainder of the local variable declaration
+ /// or an expression if no local variable declaration was found.
+ Token parseForLoopPartsMid(Token token, Token forToken) {
+ if (token != forToken.next) {
token = parseVariablesDeclarationRest(token, false);
listener.handleForInitializerLocalVariableDeclaration(token);
} else if (optional(';', token.next)) {
@@ -5369,47 +5385,17 @@
token = parseExpression(token);
listener.handleForInitializerExpressionStatement(token);
}
-
- Token next = token.next;
- if (!optional('in', next)) {
- if (optional(':', next)) {
- // Recovery
- reportRecoverableError(next, fasta.messageColonInPlaceOfIn);
- // Fall through to process `for ( ... in ... )`
- } else if (awaitToken == null || optional(';', next)) {
- // Process `for ( ... ; ... ; ... )`
- if (awaitToken != null) {
- reportRecoverableError(awaitToken, fasta.messageInvalidAwaitFor);
- }
- return parseForRest(token, forKeyword, leftParenthesis);
- } else {
- // Recovery
- reportRecoverableError(
- next, fasta.templateExpectedButGot.withArguments('in'));
- next = token.setNext(
- new SyntheticKeywordToken(Keyword.IN, next.offset)..setNext(next));
- }
- }
-
- // Process `for ( ... in ... )`
- Token identifier = beforeIdentifier.next;
- if (!identifier.isIdentifier) {
- reportRecoverableErrorWithToken(
- identifier, fasta.templateExpectedIdentifier);
- } else if (identifier != token) {
- if (optional('=', identifier.next)) {
- reportRecoverableError(
- identifier.next, fasta.messageInitializedVariableInForEach);
- } else {
- reportRecoverableErrorWithToken(
- identifier.next, fasta.templateUnexpectedToken);
- }
- } else if (awaitToken != null && !inAsync) {
- reportRecoverableError(next, fasta.messageAwaitForNotAsync);
- }
- return parseForInRest(token, awaitToken, forKeyword, leftParenthesis);
+ return token;
}
+ /// Return true if the combination of the [awaitToken] and [inKeyword]
+ /// indicate that a for loop is being parsed of the form:
+ /// (`await`)? `for` `(` type? identifier `in`
+ bool looksLikeForInLoopParts(Token awaitToken, Token inKeyword) =>
+ optional('in', inKeyword) ||
+ optional(':', inKeyword) ||
+ (!optional(';', inKeyword) && awaitToken != null);
+
/// This method parses the portion of the forLoopParts that starts with the
/// first semicolon (the one that terminates the forInitializerStatement).
///
@@ -5420,7 +5406,26 @@
/// identifier 'in' expression
/// ;
/// ```
- Token parseForRest(Token token, Token forToken, Token leftParenthesis) {
+ Token parseForRest(Token awaitToken, Token token, Token forToken) {
+ token = parseForLoopPartsRest(forToken, awaitToken, token);
+ listener.beginForStatementBody(token.next);
+ LoopState savedLoopState = loopState;
+ loopState = LoopState.InsideLoop;
+ token = parseStatement(token);
+ loopState = savedLoopState;
+ listener.endForStatementBody(token.next);
+ listener.endForStatement(token.next);
+ return token;
+ }
+
+ Token parseForLoopPartsRest(Token forToken, Token awaitToken, Token token) {
+ Token leftParenthesis = forToken.next;
+ assert(optional('for', forToken));
+ assert(optional('(', leftParenthesis));
+
+ if (awaitToken != null) {
+ reportRecoverableError(awaitToken, fasta.messageInvalidAwaitFor);
+ }
Token leftSeparator = ensureSemicolon(token);
if (optional(';', leftSeparator.next)) {
token = parseEmptyStatement(leftSeparator);
@@ -5444,14 +5449,8 @@
reportRecoverableErrorWithToken(token, fasta.templateUnexpectedToken);
token = leftParenthesis.endGroup;
}
- listener.beginForStatementBody(token.next);
- LoopState savedLoopState = loopState;
- loopState = LoopState.InsideLoop;
- token = parseStatement(token);
- loopState = savedLoopState;
- listener.endForStatementBody(token.next);
- listener.endForStatement(
- forToken, leftParenthesis, leftSeparator, expressionCount, token.next);
+ listener.handleForLoopParts(
+ forToken, leftParenthesis, leftSeparator, expressionCount);
return token;
}
@@ -5467,21 +5466,59 @@
/// ;
/// ```
Token parseForInRest(
- Token token, Token awaitToken, Token forKeyword, Token leftParenthesis) {
- Token inKeyword = token.next;
- assert(optional('in', inKeyword) || optional(':', inKeyword));
- listener.beginForInExpression(inKeyword.next);
- token = parseExpression(inKeyword);
- token = ensureCloseParen(token, leftParenthesis);
- listener.endForInExpression(token);
+ Token token, Token awaitToken, Token forToken, Token identifier) {
+ token = parseForInLoopPartsRest(forToken, token, identifier, awaitToken);
listener.beginForInBody(token.next);
LoopState savedLoopState = loopState;
loopState = LoopState.InsideLoop;
token = parseStatement(token);
loopState = savedLoopState;
listener.endForInBody(token.next);
- listener.endForIn(
- awaitToken, forKeyword, leftParenthesis, inKeyword, token.next);
+ listener.endForIn(token.next);
+ return token;
+ }
+
+ Token parseForInLoopPartsRest(
+ Token forToken, Token token, Token identifier, Token awaitToken) {
+ assert(optional('for', forToken));
+ assert(optional('(', forToken.next));
+
+ Token inKeyword = token.next;
+ if (!optional('in', inKeyword)) {
+ // Recovery
+ if (optional(':', inKeyword)) {
+ reportRecoverableError(inKeyword, fasta.messageColonInPlaceOfIn);
+ } else {
+ reportRecoverableError(
+ inKeyword, fasta.templateExpectedButGot.withArguments('in'));
+ inKeyword = token.setNext(
+ new SyntheticKeywordToken(Keyword.IN, inKeyword.offset)
+ ..setNext(inKeyword));
+ }
+ }
+
+ if (!identifier.isIdentifier) {
+ reportRecoverableErrorWithToken(
+ identifier, fasta.templateExpectedIdentifier);
+ } else if (identifier != token) {
+ if (optional('=', identifier.next)) {
+ reportRecoverableError(
+ identifier.next, fasta.messageInitializedVariableInForEach);
+ } else {
+ reportRecoverableErrorWithToken(
+ identifier.next, fasta.templateUnexpectedToken);
+ }
+ } else if (awaitToken != null && !inAsync) {
+ // TODO(danrubel): consider reporting the error on awaitToken
+ reportRecoverableError(inKeyword, fasta.messageAwaitForNotAsync);
+ }
+
+ listener.beginForInExpression(inKeyword.next);
+ token = parseExpression(inKeyword);
+ token = ensureCloseParen(token, forToken.next);
+ listener.endForInExpression(token);
+ listener.handleForInLoopParts(
+ awaitToken, forToken, forToken.next, inKeyword);
return token;
}
diff --git a/pkg/front_end/lib/src/fasta/source/stack_listener.dart b/pkg/front_end/lib/src/fasta/source/stack_listener.dart
index ea5e9b7..db6a7cd 100644
--- a/pkg/front_end/lib/src/fasta/source/stack_listener.dart
+++ b/pkg/front_end/lib/src/fasta/source/stack_listener.dart
@@ -31,6 +31,7 @@
enum NullValue {
Arguments,
As,
+ AwaitToken,
Block,
BreakTarget,
CascadeReceiver,
diff --git a/pkg/front_end/lib/src/fasta/source/type_promotion_look_ahead_listener.dart b/pkg/front_end/lib/src/fasta/source/type_promotion_look_ahead_listener.dart
index f300037..8bc01fa 100644
--- a/pkg/front_end/lib/src/fasta/source/type_promotion_look_ahead_listener.dart
+++ b/pkg/front_end/lib/src/fasta/source/type_promotion_look_ahead_listener.dart
@@ -541,9 +541,8 @@
}
@override
- void endForIn(Token awaitToken, Token forToken, Token leftParenthesis,
- Token inKeyword, Token endToken) {
- debugEvent("ForIn", awaitToken);
+ void endForIn(Token endToken) {
+ debugEvent("ForIn", endToken);
}
@override
@@ -574,13 +573,18 @@
}
@override
- void endForStatement(Token forKeyword, Token leftParen, Token leftSeparator,
- int updateExpressionCount, Token endToken) {
- debugEvent("ForStatement", forKeyword);
+ void handleForLoopParts(Token forKeyword, Token leftParen,
+ Token leftSeparator, int updateExpressionCount) {
+ debugEvent("handleForLoopParts", forKeyword);
state.discard(updateExpressionCount);
}
@override
+ void endForStatement(Token endToken) {
+ debugEvent("ForStatement", endToken);
+ }
+
+ @override
void endForStatementBody(Token token) {
debugEvent("ForStatementBody", token);
}
