De-lazify

Author: David Ungar

include/swift/Parse/Parser.h

@@ -813,9 +813,16 @@ class Parser {
                           SourceLoc OtherLoc);
 
   /// Returns the proper location for a missing right brace, parenthesis, etc.
-  SourceLoc getConfabulatedMatchingTokenLoc() const;
-  
-  SourceLoc getErrorOrMissingLocForLazyASTScopes() const;
+  SourceLoc getLocForMissingMatchingToken() const;
+
+  /// When encountering an error or a missing matching token (e.g. '}') return
+  /// its location. This value should be right at the end of the last token in
+  /// the ASTNode being parsed so that it nests within any enclosing nodes, and,
+  /// for ASTScope lookups, it does not preceed any identifiers to be looked up.
+  /// The latter case obtaines when the parsing an interpolated string literal
+  /// because there may be identifiers to be looked up and they must precede the
+  /// location of a missing close brace.
+  SourceLoc getErrorOrMissingLoc() const;
 
   /// Parse a comma separated list of some elements.
   ParserStatus parseList(tok RightK, SourceLoc LeftLoc, SourceLoc &RightLoc,

lib/Parse/ParseExpr.cpp

@@ -3434,7 +3434,7 @@ ParserResult<Expr> Parser::parseExprCollection() {
   if (Status.isError()) {
     // If we've already got errors, don't emit missing RightK diagnostics.
     RSquareLoc = Tok.is(tok::r_square) ? consumeToken()
-                                       : getConfabulatedMatchingTokenLoc();
+                                       : getLocForMissingMatchingToken();
   } else if (parseMatchingToken(tok::r_square, RSquareLoc,
                                 diag::expected_rsquare_array_expr,
                                 LSquareLoc)) {

lib/Parse/ParseType.cpp

@@ -542,10 +542,8 @@ ParserResult<TypeRepr> Parser::parseDeclResultType(Diag<> MessageID) {
 }
 
 SourceLoc Parser::getTypeErrorLoc() const {
-  /// LazyASTScopes require that the ends of types, etc. which are at the end of
-  /// \c IterableTypeContext \c Decls, such as \c StructDecl not be beyond the
-  /// end of the enclosing \c Decl.
-  return Context.LangOpts.LazyASTScopes ? getErrorOrMissingLocForLazyASTScopes() : Tok.getLoc();
+  // Use the same location as a missing close brace, etc.
+  return getErrorOrMissingLoc();
 }
 
 ParserStatus Parser::parseGenericArguments(SmallVectorImpl<TypeRepr *> &Args,

lib/Parse/Parser.cpp

@@ -980,23 +980,29 @@ bool Parser::parseMatchingToken(tok K, SourceLoc &TokLoc, Diag<> ErrorDiag,
   if (parseToken(K, TokLoc, ErrorDiag)) {
     diagnose(OtherLoc, OtherNote);
 
-    TokLoc = getConfabulatedMatchingTokenLoc();
+    TokLoc = getLocForMissingMatchingToken();
     return true;
   }
 
   return false;
 }
 
-SourceLoc Parser::getConfabulatedMatchingTokenLoc() const {
+SourceLoc Parser::getLocForMissingMatchingToken() const {
   // The right brace, parenthesis, etc. must include the whole of the previous
   // token in order so that an unexpanded lazy \c IterableTypeScope includes its
   // contents.
-  return Context.LangOpts.LazyASTScopes
-    ? getErrorOrMissingLocForLazyASTScopes()
-    : PreviousLoc;
+  return getErrorOrMissingLoc();
 }
 
-SourceLoc Parser::getErrorOrMissingLocForLazyASTScopes() const {
+SourceLoc Parser::getErrorOrMissingLoc() const {
+  // LazyASTScopes require that the ends of types, etc. which are at the end of
+  // \c IterableTypeContext \c Decls, such as \c StructDecl not be beyond the
+  // end of the enclosing \c Decl.
+
+  // The missing right brace, parenthesis, etc. must include the whole of the
+  // previous token in order so that an unexpanded lazy \c IterableTypeScope
+  // includes its contents.
+
   auto const PreviousTok = Lexer::getTokenAtLocation(Context.SourceMgr,
                                                      PreviousLoc);
   // If it's a string literal, it might be an InterpolatedStringLiteral.
@@ -1114,7 +1120,7 @@ Parser::parseList(tok RightK, SourceLoc LeftLoc, SourceLoc &RightLoc,
   if (Status.isError()) {
     // If we've already got errors, don't emit missing RightK diagnostics.
     RightLoc =
-        Tok.is(RightK) ? consumeToken() : getConfabulatedMatchingTokenLoc();
+        Tok.is(RightK) ? consumeToken() : getLocForMissingMatchingToken();
   } else if (parseMatchingToken(RightK, RightLoc, ErrorDiag, LeftLoc)) {
     Status.setIsParseError();
   }