[parser] Fix tuple type round-tripping issue

`public init(a: (b || c))` became `public init(a: )(b || c)` after
round-tripping.

Resolves rdar://problem/55280477

Author: Nathan Hawes

include/swift/Parse/Parser.h

@@ -876,7 +876,7 @@ class Parser {
   ///
   /// If the input is malformed, this emits the specified error diagnostic.
   bool parseToken(tok K, SourceLoc &TokLoc, const Diagnostic &D);
-  llvm::Optional<ParsedTokenSyntax> parseTokenSyntax(tok K,
+  llvm::Optional<ParsedTokenSyntax> parseTokenSyntax(tok K, SourceLoc &TokLoc,
                                                      const Diagnostic &D);
 
   template<typename ...DiagArgTypes, typename ...ArgTypes>
@@ -896,7 +896,8 @@ class Parser {
                           SourceLoc OtherLoc);
 
   llvm::Optional<ParsedTokenSyntax>
-  parseMatchingTokenSyntax(tok K, Diag<> ErrorDiag, SourceLoc OtherLoc);
+  parseMatchingTokenSyntax(tok K, SourceLoc &TokLoc, Diag<> ErrorDiag,
+                           SourceLoc OtherLoc);
 
   /// Returns the proper location for a missing right brace, parenthesis, etc.
   SourceLoc getLocForMissingMatchingToken() const;

lib/Parse/ParseType.cpp

@@ -109,7 +109,8 @@ Parser::parseLayoutConstraintSyntax() {
     if (Tok.is(tok::r_paren))
       builder.useRightParen(consumeTokenSyntax(tok::r_paren));
   } else {
-    auto rParen = parseMatchingTokenSyntax(tok::r_paren,
+    SourceLoc rParenLoc;
+    auto rParen = parseMatchingTokenSyntax(tok::r_paren, rParenLoc,
                              diag::expected_rparen_layout_constraint,
                              lParenLoc);
     if (rParen)
@@ -1166,6 +1167,8 @@ Parser::TypeResult Parser::parseTypeTupleBody() {
   });
 
   if (!Status.isSuccess()) {
+    if (RParen)
+      Junk.push_back(std::move(*RParen));
     auto ty = ParsedSyntaxRecorder::makeUnknownType(Junk, *SyntaxContext);
     return makeParsedResult(std::move(ty), Status);
   }
@@ -1253,9 +1256,9 @@ Parser::TypeResult Parser::parseTypeArray(ParsedTypeSyntax Base,
   // Ignore integer literal between '[' and ']'
   ignoreIf(tok::integer_literal);
 
-  auto RSquareLoc = Tok.getLoc();
+  SourceLoc RSquareLoc;
   auto RSquare = parseMatchingTokenSyntax(
-      tok::r_square, diag::expected_rbracket_array_type, LSquareLoc);
+      tok::r_square, RSquareLoc, diag::expected_rbracket_array_type, LSquareLoc);
 
   if (RSquare) {
     // If we parsed something valid, diagnose it with a fixit to rewrite it to
@@ -1301,7 +1304,9 @@ Parser::TypeResult Parser::parseTypeCollection() {
   auto Diag = Colon ? diag::expected_rbracket_dictionary_type
                     : diag::expected_rbracket_array_type;
 
-  auto RSquare = parseMatchingTokenSyntax(tok::r_square, Diag, LSquareLoc);
+  SourceLoc RSquareLoc;
+  auto RSquare = parseMatchingTokenSyntax(tok::r_square, RSquareLoc, Diag,
+                                          LSquareLoc);
   if (!RSquare)
     Status.setIsParseError();
 

lib/Parse/Parser.cpp

@@ -1242,8 +1242,10 @@ bool Parser::parseMatchingToken(tok K, SourceLoc &TokLoc, Diag<> ErrorDiag,
   return false;
 }
 
-Optional<ParsedTokenSyntax> Parser::parseTokenSyntax(tok K, const Diagnostic &D) {
+Optional<ParsedTokenSyntax> Parser::parseTokenSyntax(tok K, SourceLoc &TokLoc,
+                                                     const Diagnostic &D) {
   if (Tok.is(K)) {
+    TokLoc = Tok.getLoc();
     return consumeTokenSyntax();
   }
 
@@ -1253,7 +1255,7 @@ Optional<ParsedTokenSyntax> Parser::parseTokenSyntax(tok K, const Diagnostic &D)
 }
 
 Optional<ParsedTokenSyntax>
-Parser::parseMatchingTokenSyntax(tok K, Diag<> ErrorDiag, SourceLoc OtherLoc) {
+Parser::parseMatchingTokenSyntax(tok K, SourceLoc &TokLoc, Diag<> ErrorDiag, SourceLoc OtherLoc) {
   Diag<> OtherNote;
   switch (K) {
   case tok::r_paren:  OtherNote = diag::opening_paren; break;
@@ -1262,9 +1264,11 @@ Parser::parseMatchingTokenSyntax(tok K, Diag<> ErrorDiag, SourceLoc OtherLoc) {
   default: llvm_unreachable("unknown matching token!");
   }
 
-  auto Token = parseTokenSyntax(K, ErrorDiag);
-  if (!Token)
+  auto Token = parseTokenSyntax(K, TokLoc, ErrorDiag);
+  if (!Token) {
+    TokLoc = getLocForMissingMatchingToken();
     diagnose(OtherLoc, OtherNote);
+  }
   return Token;
 }
 
@@ -1391,9 +1395,14 @@ Parser::parseListSyntax(tok RightK, SourceLoc LeftLoc,
 
   if (Status.isError()) {
     // If we've already got errors, don't emit missing RightK diagnostics.
-    RightLoc = Tok.is(RightK) ? consumeToken() : PreviousLoc;
+    if (Tok.is(RightK)) {
+      RightLoc = Tok.getLoc();
+      Right = consumeTokenSyntax(RightK);
+    } else {
+      RightLoc = getLocForMissingMatchingToken();
+    }
   } else {
-    Right = parseMatchingTokenSyntax(RightK, ErrorDiag, LeftLoc);
+    Right = parseMatchingTokenSyntax(RightK, RightLoc, ErrorDiag, LeftLoc);
     if (!Right)
       Status.setIsParseError();
   }

test/Syntax/Outputs/round_trip_invalid.swift.withkinds

@@ -19,4 +19,5 @@ class C <MemberDeclBlock>{<MemberDeclListItem><StructDecl>
 struct S <MemberDeclBlock>{<MemberDeclListItem><EnumDecl>
 enum E <MemberDeclBlock>{<MemberDeclListItem><ProtocolDecl>
 protocol P <MemberDeclBlock>{<MemberDeclListItem><ExtensionDecl>
-extension <SimpleTypeIdentifier>P </SimpleTypeIdentifier><MemberDeclBlock>{</MemberDeclBlock></ExtensionDecl></MemberDeclListItem></MemberDeclBlock></ProtocolDecl></MemberDeclListItem></MemberDeclBlock></EnumDecl></MemberDeclListItem></MemberDeclBlock></StructDecl></MemberDeclListItem></MemberDeclBlock></ClassDecl></CodeBlock></FunctionDecl>
+extension <SimpleTypeIdentifier>P </SimpleTypeIdentifier><MemberDeclBlock>{<MemberDeclListItem><InitializerDecl><DeclModifier>
+public </DeclModifier>init<ParameterClause>(<FunctionParameter>a: (<TupleTypeElement><SimpleTypeIdentifier>Int </SimpleTypeIdentifier></TupleTypeElement>|| String)</FunctionParameter>)</ParameterClause></InitializerDecl></MemberDeclListItem></MemberDeclBlock></ExtensionDecl></MemberDeclListItem></MemberDeclBlock></ProtocolDecl></MemberDeclListItem></MemberDeclBlock></EnumDecl></MemberDeclListItem></MemberDeclBlock></StructDecl></MemberDeclListItem></MemberDeclBlock></ClassDecl></CodeBlock></FunctionDecl>

test/Syntax/round_trip_invalid.swift

@@ -20,3 +20,4 @@ struct S {
 enum E {
 protocol P {
 extension P {
+public init(a: (Int || String))