libSyntax: specialize closure expression. (#13421)

Author: nkcsgexi

lib/Parse/ParseExpr.cpp

@@ -2642,7 +2642,7 @@ parseClosureSignatureIfPresent(SmallVectorImpl<CaptureListEntry> &captureList,
 
 ParserResult<Expr> Parser::parseExprClosure() {
   assert(Tok.is(tok::l_brace) && "Not at a left brace?");
-
+  SyntaxParsingContext ClosureContext(SyntaxContext, SyntaxKind::ClosureExpr);
   // We may be parsing this closure expr in a matching pattern context.  If so,
   // reset our state to not be in a pattern for any recursive pattern parses.
   llvm::SaveAndRestore<decltype(InVarOrLetPattern)>

test/Syntax/Outputs/round_trip_parse_gen.swift.withkinds

@@ -128,25 +128,28 @@ func tryfoo<FunctionSignature><ParameterClause>() </ParameterClause></FunctionSi
   try! <MemberAccessExpr><IdentifierExpr>foo</IdentifierExpr>().bar</MemberAccessExpr>().foo().bar()</TryExpr>
 }</CodeBlock></FunctionDecl><FunctionDecl>
 
-func closure<FunctionSignature><ParameterClause>() </ParameterClause></FunctionSignature><CodeBlock>{
+func closure<FunctionSignature><ParameterClause>() </ParameterClause></FunctionSignature><CodeBlock>{<ClosureExpr>
   {<ClosureSignature><ClosureCaptureSignature>[<ClosureCaptureItem>weak <IdentifierExpr>a</IdentifierExpr>,</ClosureCaptureItem><ClosureCaptureItem>
     unowned(safe) self,</ClosureCaptureItem><ClosureCaptureItem>
     b = <IntegerLiteralExpr>3</IntegerLiteralExpr>,</ClosureCaptureItem><ClosureCaptureItem>
     unowned(unsafe) c = <MemberAccessExpr><IdentifierExpr>foo</IdentifierExpr>().bar</MemberAccessExpr></ClosureCaptureItem>] </ClosureCaptureSignature>in</ClosureSignature>
-  }
-  {<ClosureSignature><ClosureCaptureSignature>[] </ClosureCaptureSignature>in </ClosureSignature>}
+  }</ClosureExpr><ClosureExpr>
+  {<ClosureSignature><ClosureCaptureSignature>[] </ClosureCaptureSignature>in </ClosureSignature>}</ClosureExpr><ClosureExpr>
 
   { <ClosureSignature><ClosureCaptureSignature>[] </ClosureCaptureSignature><ClosureParam>a, </ClosureParam><ClosureParam>b, </ClosureParam><ClosureParam>_ </ClosureParam><ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause>in</ClosureSignature><ReturnStmt>
     return <IntegerLiteralExpr>2</IntegerLiteralExpr></ReturnStmt>
-  }
+  }</ClosureExpr><ClosureExpr>
   { <ClosureSignature><ClosureCaptureSignature>[] </ClosureCaptureSignature><ParameterClause>(<FunctionParameter>a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier>, </FunctionParameter><FunctionParameter>b: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier>, </FunctionParameter><FunctionParameter>_: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause><ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause>in</ClosureSignature><ReturnStmt>
     return <IntegerLiteralExpr>2</IntegerLiteralExpr></ReturnStmt>
-  }
+  }</ClosureExpr><ClosureExpr>
   { <ClosureSignature><ClosureCaptureSignature>[] </ClosureCaptureSignature><ClosureParam>a, </ClosureParam><ClosureParam>b, </ClosureParam><ClosureParam>_ </ClosureParam>throws <ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause>in</ClosureSignature><ReturnStmt>
     return <IntegerLiteralExpr>2</IntegerLiteralExpr></ReturnStmt>
-  }
+  }</ClosureExpr><ClosureExpr>
   { <ClosureSignature><ClosureCaptureSignature>[] </ClosureCaptureSignature><ParameterClause>(<FunctionParameter>a: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier>, </FunctionParameter><FunctionParameter>_ b: <SimpleTypeIdentifier>Int</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause>throws <ReturnClause>-> <SimpleTypeIdentifier>Int </SimpleTypeIdentifier></ReturnClause>in</ClosureSignature><ReturnStmt>
     return <IntegerLiteralExpr>2</IntegerLiteralExpr></ReturnStmt>
-  }
-  { <ClosureSignature><ClosureParam>a, </ClosureParam><ClosureParam>b </ClosureParam>in </ClosureSignature>}
+  }</ClosureExpr><ClosureExpr>
+  { <ClosureSignature><ClosureParam>a, </ClosureParam><ClosureParam>b </ClosureParam>in </ClosureSignature>}</ClosureExpr><ClosureExpr>
+  {}</ClosureExpr><ClosureExpr>
+  { <ClosureSignature><ClosureParam>s1, </ClosureParam><ClosureParam>s2 </ClosureParam>in </ClosureSignature><SequenceExpr><IdentifierExpr>s1 </IdentifierExpr><BinaryOperatorExpr>> </BinaryOperatorExpr><IdentifierExpr>s2 </IdentifierExpr></SequenceExpr>}</ClosureExpr><ClosureExpr>
+  { <SequenceExpr>$0 <BinaryOperatorExpr>> </BinaryOperatorExpr>$1 </SequenceExpr>}</ClosureExpr>
 }</CodeBlock></FunctionDecl>

test/Syntax/round_trip_parse_gen.swift

@@ -149,4 +149,7 @@ func closure() {
     return 2
   }
   { a, b in }
+  {}
+  { s1, s2 in s1 > s2 }
+  { $0 > $1 }
 }

utils/gyb_syntax_support/ExprNodes.py

@@ -307,4 +307,12 @@
              Child('Output', kind='ReturnClause', is_optional=True),
              Child('InTok', kind='InToken'),
          ]),
+
+    Node('ClosureExpr', kind='Expr',
+         children=[
+             Child('LeftBrace', kind='LeftBraceToken'),
+             Child('Signature', kind='ClosureSignature', is_optional=True),
+             Child('Statements', kind='StmtList'),
+             Child('RightBrace', kind='RightBraceToken'),
+         ]),
 ]