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Merged
merged 1 commit into from
Mar 27, 2018
Merged

[Syntax] Parse 'switch' statement #15537

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34 changes: 24 additions & 10 deletions lib/Parse/ParseStmt.cpp
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Expand Up @@ -1966,6 +1966,7 @@ ParserResult<Stmt> Parser::parseStmtForEach(LabeledStmtInfo LabelInfo) {
/// stmt-switch:
/// (identifier ':')? 'switch' expr-basic '{' stmt-case+ '}'
ParserResult<Stmt> Parser::parseStmtSwitch(LabeledStmtInfo LabelInfo) {
SyntaxContext->setCreateSyntax(SyntaxKind::SwitchStmt);
SourceLoc SwitchLoc = consumeToken(tok::kw_switch);

ParserStatus Status;
Expand Down Expand Up @@ -2020,6 +2021,7 @@ ParserResult<Stmt> Parser::parseStmtSwitch(LabeledStmtInfo LabelInfo) {

ParserStatus
Parser::parseStmtCases(SmallVectorImpl<ASTNode> &cases, bool IsActive) {
SyntaxParsingContext CasesContext(SyntaxContext, SyntaxKind::SwitchCaseList);
ParserStatus Status;
while (Tok.isNot(tok::r_brace, tok::eof,
tok::pound_endif, tok::pound_elseif, tok::pound_else)) {
Expand Down Expand Up @@ -2076,21 +2078,30 @@ static ParserStatus parseStmtCase(Parser &P, SourceLoc &CaseLoc,
SmallVectorImpl<CaseLabelItem> &LabelItems,
SmallVectorImpl<VarDecl *> &BoundDecls,
SourceLoc &ColonLoc) {
SyntaxParsingContext CaseContext(P.SyntaxContext,
SyntaxKind::SwitchCaseLabel);
ParserStatus Status;
bool isFirst = true;

CaseLoc = P.consumeToken(tok::kw_case);

do {
GuardedPattern PatternResult;
parseGuardedPattern(P, PatternResult, Status, BoundDecls,
GuardedPatternContext::Case, isFirst);
LabelItems.push_back(CaseLabelItem(/*IsDefault=*/false,
PatternResult.ThePattern,
PatternResult.WhereLoc,
PatternResult.Guard));
isFirst = false;
} while (P.consumeIf(tok::comma));
{
SyntaxParsingContext ListContext(P.SyntaxContext, SyntaxKind::CaseItemList);

while (true) {
SyntaxParsingContext ItemContext(P.SyntaxContext, SyntaxKind::CaseItem);
GuardedPattern PatternResult;
parseGuardedPattern(P, PatternResult, Status, BoundDecls,
GuardedPatternContext::Case, isFirst);
LabelItems.push_back(
CaseLabelItem(/*IsDefault=*/false, PatternResult.ThePattern,
PatternResult.WhereLoc, PatternResult.Guard));
isFirst = false;
if (P.consumeIf(tok::comma))
continue;
break;
}
}

ColonLoc = P.Tok.getLoc();
if (!P.Tok.is(tok::colon)) {
Expand All @@ -2106,6 +2117,8 @@ static ParserStatus
parseStmtCaseDefault(Parser &P, SourceLoc &CaseLoc,
SmallVectorImpl<CaseLabelItem> &LabelItems,
SourceLoc &ColonLoc) {
SyntaxParsingContext CaseContext(P.SyntaxContext,
SyntaxKind::SwitchDefaultLabel);
ParserStatus Status;

CaseLoc = P.consumeToken(tok::kw_default);
Expand Down Expand Up @@ -2137,6 +2150,7 @@ parseStmtCaseDefault(Parser &P, SourceLoc &CaseLoc,
}

ParserResult<CaseStmt> Parser::parseStmtCase(bool IsActive) {
SyntaxParsingContext CaseContext(SyntaxContext, SyntaxKind::SwitchCase);
// A case block has its own scope for variables bound out of the pattern.
Scope S(this, ScopeKind::CaseVars, !IsActive);

Expand Down
2 changes: 0 additions & 2 deletions lib/Syntax/Status.md
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Expand Up @@ -92,8 +92,6 @@
* GuardStmt
* WhileStmt
* ForInStmt

### Not-started (UnknownStmt):
* SwitchStmt

## Pattern
Expand Down
57 changes: 35 additions & 22 deletions test/Syntax/Outputs/round_trip_parse_gen.swift.withkinds
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Expand Up @@ -302,18 +302,18 @@ class C <MemberDeclBlock>{<VariableDecl><Attribute>
}</CodeBlock></FunctionDecl>
}</MemberDeclBlock></ClassDecl><DoStmt>

do <CodeBlock>{
switch <IdentifierExpr>foo </IdentifierExpr>{
case <ValueBindingPattern>let <IdentifierPattern>a</IdentifierPattern></ValueBindingPattern>: <BreakStmt>break</BreakStmt>
case <ValueBindingPattern>let <ExpressionPattern><SequenceExpr><UnresolvedPatternExpr><IdentifierPattern>a </IdentifierPattern></UnresolvedPatternExpr><AsExpr>as <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></AsExpr></SequenceExpr></ExpressionPattern></ValueBindingPattern>: <BreakStmt>break</BreakStmt>
case <ValueBindingPattern>let <ExpressionPattern><TupleExpr>(<TupleElement><UnresolvedPatternExpr><IdentifierPattern>a</IdentifierPattern></UnresolvedPatternExpr>, </TupleElement><TupleElement><UnresolvedPatternExpr><IdentifierPattern>b</IdentifierPattern></UnresolvedPatternExpr></TupleElement>)</TupleExpr></ExpressionPattern></ValueBindingPattern>: <BreakStmt>break</BreakStmt>
case <ExpressionPattern><TupleExpr>(<TupleElement><UnresolvedPatternExpr><ValueBindingPattern>let <IdentifierPattern>a</IdentifierPattern></ValueBindingPattern></UnresolvedPatternExpr>, </TupleElement><TupleElement><UnresolvedPatternExpr><ValueBindingPattern>var <IdentifierPattern>b</IdentifierPattern></ValueBindingPattern></UnresolvedPatternExpr></TupleElement>)</TupleExpr></ExpressionPattern>: <BreakStmt>break</BreakStmt>
case <IsTypePattern>is <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></IsTypePattern>: <BreakStmt>break</BreakStmt>
case <ValueBindingPattern>let <ExpressionPattern><FunctionCallExpr><ImplicitMemberExpr>.bar</ImplicitMemberExpr>(<FunctionCallArgument><UnresolvedPatternExpr><IdentifierPattern>x</IdentifierPattern></UnresolvedPatternExpr></FunctionCallArgument>)</FunctionCallExpr></ExpressionPattern></ValueBindingPattern>: <BreakStmt>break</BreakStmt>
case <ExpressionPattern><MemberAccessExpr><IdentifierExpr>MyEnum</IdentifierExpr>.foo</MemberAccessExpr></ExpressionPattern>: <BreakStmt>break</BreakStmt>
case <ValueBindingPattern>let <ExpressionPattern><SequenceExpr><UnresolvedPatternExpr><IdentifierPattern>a </IdentifierPattern></UnresolvedPatternExpr><AsExpr>as <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></AsExpr></SequenceExpr></ExpressionPattern></ValueBindingPattern>: <BreakStmt>break</BreakStmt>
case <ValueBindingPattern>let <ExpressionPattern><OptionalChainingExpr><UnresolvedPatternExpr><IdentifierPattern>a</IdentifierPattern></UnresolvedPatternExpr>?</OptionalChainingExpr></ExpressionPattern></ValueBindingPattern>: <BreakStmt>break</BreakStmt>
}
do <CodeBlock>{<SwitchStmt>
switch <IdentifierExpr>foo </IdentifierExpr>{<SwitchCase><SwitchCaseLabel>
case <CaseItem><ValueBindingPattern>let <IdentifierPattern>a</IdentifierPattern></ValueBindingPattern></CaseItem>: </SwitchCaseLabel><BreakStmt>break</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ValueBindingPattern>let <ExpressionPattern><SequenceExpr><UnresolvedPatternExpr><IdentifierPattern>a </IdentifierPattern></UnresolvedPatternExpr><AsExpr>as <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></AsExpr></SequenceExpr></ExpressionPattern></ValueBindingPattern></CaseItem>: </SwitchCaseLabel><BreakStmt>break</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ValueBindingPattern>let <ExpressionPattern><TupleExpr>(<TupleElement><UnresolvedPatternExpr><IdentifierPattern>a</IdentifierPattern></UnresolvedPatternExpr>, </TupleElement><TupleElement><UnresolvedPatternExpr><IdentifierPattern>b</IdentifierPattern></UnresolvedPatternExpr></TupleElement>)</TupleExpr></ExpressionPattern></ValueBindingPattern></CaseItem>: </SwitchCaseLabel><BreakStmt>break</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ExpressionPattern><TupleExpr>(<TupleElement><UnresolvedPatternExpr><ValueBindingPattern>let <IdentifierPattern>a</IdentifierPattern></ValueBindingPattern></UnresolvedPatternExpr>, </TupleElement><TupleElement><UnresolvedPatternExpr><ValueBindingPattern>var <IdentifierPattern>b</IdentifierPattern></ValueBindingPattern></UnresolvedPatternExpr></TupleElement>)</TupleExpr></ExpressionPattern></CaseItem>: </SwitchCaseLabel><BreakStmt>break</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><IsTypePattern>is <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></IsTypePattern></CaseItem>: </SwitchCaseLabel><BreakStmt>break</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ValueBindingPattern>let <ExpressionPattern><FunctionCallExpr><ImplicitMemberExpr>.bar</ImplicitMemberExpr>(<FunctionCallArgument><UnresolvedPatternExpr><IdentifierPattern>x</IdentifierPattern></UnresolvedPatternExpr></FunctionCallArgument>)</FunctionCallExpr></ExpressionPattern></ValueBindingPattern></CaseItem>: </SwitchCaseLabel><BreakStmt>break</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ExpressionPattern><MemberAccessExpr><IdentifierExpr>MyEnum</IdentifierExpr>.foo</MemberAccessExpr></ExpressionPattern></CaseItem>: </SwitchCaseLabel><BreakStmt>break</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ValueBindingPattern>let <ExpressionPattern><SequenceExpr><UnresolvedPatternExpr><IdentifierPattern>a </IdentifierPattern></UnresolvedPatternExpr><AsExpr>as <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></AsExpr></SequenceExpr></ExpressionPattern></ValueBindingPattern></CaseItem>: </SwitchCaseLabel><BreakStmt>break</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ValueBindingPattern>let <ExpressionPattern><OptionalChainingExpr><UnresolvedPatternExpr><IdentifierPattern>a</IdentifierPattern></UnresolvedPatternExpr>?</OptionalChainingExpr></ExpressionPattern></ValueBindingPattern></CaseItem>: </SwitchCaseLabel><BreakStmt>break</BreakStmt></SwitchCase>
}</SwitchStmt>
}</CodeBlock></DoStmt><FunctionDecl>

func statementTests<FunctionSignature><ParameterClause>() </ParameterClause></FunctionSignature><CodeBlock>{<DoStmt>
Expand All @@ -327,15 +327,15 @@ func statementTests<FunctionSignature><ParameterClause>() </ParameterClause></Fu
LABEL: repeat <CodeBlock>{ } </CodeBlock>while <BooleanLiteralExpr>false</BooleanLiteralExpr></RepeatWhileStmt><WhileStmt>
while <ConditionElement><BooleanLiteralExpr>true </BooleanLiteralExpr></ConditionElement><CodeBlock>{ }</CodeBlock></WhileStmt><WhileStmt>
LABEL: while <ConditionElement><BooleanLiteralExpr>true </BooleanLiteralExpr></ConditionElement><CodeBlock>{ }</CodeBlock></WhileStmt><DoStmt>
LABEL: do <CodeBlock>{}</CodeBlock></DoStmt>
LABEL: switch <IdentifierExpr>foo </IdentifierExpr>{
case <ExpressionPattern><IntegerLiteralExpr>1</IntegerLiteralExpr></ExpressionPattern>:<FallthroughStmt>
fallthrough</FallthroughStmt>
case <ExpressionPattern><IntegerLiteralExpr>2</IntegerLiteralExpr></ExpressionPattern>:<BreakStmt>
break LABEL</BreakStmt>
case <ExpressionPattern><IntegerLiteralExpr>3</IntegerLiteralExpr></ExpressionPattern>:<BreakStmt>
break</BreakStmt>
}<ForInStmt>
LABEL: do <CodeBlock>{}</CodeBlock></DoStmt><SwitchStmt>
LABEL: switch <IdentifierExpr>foo </IdentifierExpr>{<SwitchCase><SwitchCaseLabel>
case <CaseItem><ExpressionPattern><IntegerLiteralExpr>1</IntegerLiteralExpr></ExpressionPattern></CaseItem>:</SwitchCaseLabel><FallthroughStmt>
fallthrough</FallthroughStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ExpressionPattern><IntegerLiteralExpr>2</IntegerLiteralExpr></ExpressionPattern></CaseItem>:</SwitchCaseLabel><BreakStmt>
break LABEL</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ExpressionPattern><IntegerLiteralExpr>3</IntegerLiteralExpr></ExpressionPattern></CaseItem>:</SwitchCaseLabel><BreakStmt>
break</BreakStmt></SwitchCase>
}</SwitchStmt><ForInStmt>

for <IdentifierPattern>a </IdentifierPattern>in <IdentifierExpr>b </IdentifierExpr><CodeBlock>{<DeferStmt>
defer <CodeBlock>{ <TupleExpr>() </TupleExpr>}</CodeBlock></DeferStmt><IfStmt>
Expand All @@ -361,7 +361,20 @@ func statementTests<FunctionSignature><ParameterClause>() </ParameterClause></Fu
guard <ConditionElement><OptionalBindingCondition>let <IdentifierPattern>a </IdentifierPattern><InitializerClause>= <IdentifierExpr>b </IdentifierExpr></InitializerClause></OptionalBindingCondition></ConditionElement>else <CodeBlock>{}</CodeBlock></GuardStmt><ForInStmt>

for <ValueBindingPattern>var <IdentifierPattern>i </IdentifierPattern></ValueBindingPattern>in <IdentifierExpr>foo </IdentifierExpr><WhereClause>where <MemberAccessExpr><IdentifierExpr>i</IdentifierExpr>.foo </MemberAccessExpr></WhereClause><CodeBlock>{}</CodeBlock></ForInStmt><ForInStmt>
for case <IsTypePattern>is <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></IsTypePattern>in <IdentifierExpr>foo </IdentifierExpr><CodeBlock>{}</CodeBlock></ForInStmt>
for case <IsTypePattern>is <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></IsTypePattern>in <IdentifierExpr>foo </IdentifierExpr><CodeBlock>{}</CodeBlock></ForInStmt><SwitchStmt>

switch <IdentifierExpr>Foo </IdentifierExpr>{<SwitchCase><SwitchCaseLabel>
case <CaseItem><ExpressionPattern><IdentifierExpr>n1</IdentifierExpr></ExpressionPattern></CaseItem>:</SwitchCaseLabel><BreakStmt>
break</BreakStmt></SwitchCase><SwitchCase><SwitchCaseLabel>
case <CaseItem><ExpressionPattern><IdentifierExpr>n2</IdentifierExpr></ExpressionPattern>, </CaseItem><CaseItem><ExpressionPattern><IdentifierExpr>n3l</IdentifierExpr></ExpressionPattern></CaseItem>:</SwitchCaseLabel><BreakStmt>
break</BreakStmt></SwitchCase><IfConfigDecl>
#if <IdentifierExpr>FOO</IdentifierExpr><SwitchCase><SwitchCaseLabel>
case <CaseItem><ValueBindingPattern>let <ExpressionPattern><TupleExpr>(<TupleElement><UnresolvedPatternExpr><IdentifierPattern>x</IdentifierPattern></UnresolvedPatternExpr>, </TupleElement><TupleElement><UnresolvedPatternExpr><IdentifierPattern>y</IdentifierPattern></UnresolvedPatternExpr></TupleElement>) </TupleExpr></ExpressionPattern></ValueBindingPattern><WhereClause>where <PrefixOperatorExpr>!<IdentifierExpr>x</IdentifierExpr></PrefixOperatorExpr></WhereClause>, </CaseItem><CaseItem><ExpressionPattern><IdentifierExpr>n3l </IdentifierExpr></ExpressionPattern><WhereClause>where <BooleanLiteralExpr>false</BooleanLiteralExpr></WhereClause></CaseItem>:</SwitchCaseLabel><BreakStmt>
break</BreakStmt></SwitchCase>
#endif</IfConfigDecl><SwitchCase><SwitchDefaultLabel>
default:</SwitchDefaultLabel><BreakStmt>
break</BreakStmt></SwitchCase>
}</SwitchStmt>
}</CodeBlock></FunctionDecl><ExtensionDecl>

// MARK: - ExtensionDecl
Expand Down
13 changes: 13 additions & 0 deletions test/Syntax/round_trip_parse_gen.swift
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Expand Up @@ -362,6 +362,19 @@ func statementTests() {

for var i in foo where i.foo {}
for case is Int in foo {}

switch Foo {
case n1:
break
case n2, n3l:
break
#if FOO
case let (x, y) where !x, n3l where false:
break
#endif
default:
break
}
}

// MARK: - ExtensionDecl
Expand Down
6 changes: 4 additions & 2 deletions utils/gyb_syntax_support/DeclNodes.py
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Expand Up @@ -96,11 +96,13 @@
# if-config-decl -> '#if' expr stmt-list else-if-directive-clause-list
# else-clause? '#endif'
Node('IfConfigDecl', kind='Decl',
traits=['WithStatements'],
children=[
Child('PoundIf', kind='PoundIfToken'),
Child('Condition', kind='Expr'),
Child('Statements', kind='CodeBlockItemList'),
Child('Elements', kind='Syntax',
node_choices=[
Child('Statements', kind='CodeBlockItemList'),
Child('SwitchCases', kind='SwitchCaseList')]),
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I wonder if there’s anything we could do to try to merge these

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Dropping WithStatements trait from IfConfigDecl.
But separating IfConfigDecl only for switch-cases (i.e. SwitchCaseIfConfig) doesn't seem the right choice.

Child('ElseifDirectiveClauses', kind='ElseifDirectiveClauseList',
is_optional=True),
Child('ElseClause', kind='ElseDirectiveClause',
Expand Down
9 changes: 7 additions & 2 deletions utils/gyb_syntax_support/StmtNodes.py
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Expand Up @@ -39,7 +39,8 @@

# switch-case-list -> switch-case switch-case-list?
Node('SwitchCaseList', kind='SyntaxCollection',
element='SwitchCase'),
element='Syntax',
element_choices=['SwitchCase', 'IfConfigDecl']),

# repeat-while-stmt -> label? ':'? 'repeat' code-block 'while' expr ';'?
Node('RepeatWhileStmt', kind='Stmt',
Expand Down Expand Up @@ -257,7 +258,11 @@
Node('SwitchCase', kind='Syntax',
traits=['WithStatements'],
children=[
Child('Label', kind='Syntax'),
Child('Label', kind='Syntax',
node_choices=[
Child('Default', kind='SwitchDefaultLabel'),
Child('Case', kind='SwitchCaseLabel'),
]),
Child('Statements', kind='CodeBlockItemList'),
]),

Expand Down