[Parse] Simplify parseIdentifierDeclName()

As a preparation for syntax parsing.

Author: rintaro

lib/Parse/ParseDecl.cpp

@@ -3518,16 +3518,10 @@ ParserStatus Parser::parseInheritance(SmallVectorImpl<TypeLoc> &Inherited,
   return Status;
 }
 
-enum class TokenProperty {
-  None,
-  StartsWithLess,
-};
-
 static ParserStatus
 parseIdentifierDeclName(Parser &P, Identifier &Result, SourceLoc &Loc,
-                        StringRef DeclKindName, tok ResyncT1, tok ResyncT2,
-                        tok ResyncT3, tok ResyncT4,
-                        TokenProperty ResyncP1) {
+                        StringRef DeclKindName,
+                        llvm::function_ref<bool(const Token &)> canRecover) {
   if (P.Tok.is(tok::identifier)) {
     Loc = P.consumeIdentifier(&Result);
 
@@ -3566,9 +3560,7 @@ parseIdentifierDeclName(Parser &P, Identifier &Result, SourceLoc &Loc,
       .fixItReplace(P.Tok.getLoc(), "`" + P.Tok.getText().str() + "`");
 
     // Recover if the next token is one of the expected tokens.
-    auto Next = P.peekToken();
-    if (Next.isAny(ResyncT1, ResyncT2, ResyncT3, ResyncT4) ||
-        (ResyncP1 != TokenProperty::None && P.startsWithLess(Next))) {
+    if (canRecover(P.peekToken())) {
       llvm::SmallString<32> Name(P.Tok.getText());
       // Append an invalid character so that nothing can resolve to this name.
       Name += "#";
@@ -3585,38 +3577,6 @@ parseIdentifierDeclName(Parser &P, Identifier &Result, SourceLoc &Loc,
   return makeParserError();
 }
 
-static ParserStatus
-parseIdentifierDeclName(Parser &P, Identifier &Result, SourceLoc &L,
-                        StringRef DeclKindName, tok ResyncT1, tok ResyncT2) {
-  return parseIdentifierDeclName(P, Result, L, DeclKindName, ResyncT1, ResyncT2,
-                                 tok::NUM_TOKENS, tok::NUM_TOKENS,
-                                 TokenProperty::None);
-}
-
-static ParserStatus
-parseIdentifierDeclName(Parser &P, Identifier &Result, SourceLoc &L,
-                        StringRef DeclKindName, tok ResyncT1, tok ResyncT2,
-                        tok ResyncT3, tok ResyncT4) {
-  return parseIdentifierDeclName(P, Result, L, DeclKindName, ResyncT1, ResyncT2,
-                                 ResyncT3, ResyncT4, TokenProperty::None);
-}
-
-static ParserStatus
-parseIdentifierDeclName(Parser &P, Identifier &Result, SourceLoc &L,
-                        StringRef DeclKindName, tok ResyncT1, tok ResyncT2,
-                        TokenProperty ResyncP1) {
-  return parseIdentifierDeclName(P, Result, L, DeclKindName, ResyncT1, ResyncT2,
-                                 tok::NUM_TOKENS, tok::NUM_TOKENS, ResyncP1);
-}
-
-static ParserStatus
-parseIdentifierDeclName(Parser &P, Identifier &Result, SourceLoc &L,
-                        StringRef DeclKindName, tok ResyncT1, tok ResyncT2,
-                        tok ResyncT3, TokenProperty ResyncP1) {
-  return parseIdentifierDeclName(P, Result, L, DeclKindName, ResyncT1, ResyncT2,
-                                 ResyncT3, tok::NUM_TOKENS, ResyncP1);
-}
-
 /// Add a fix-it to remove the space in consecutive identifiers.
 /// Add a camel-cased option if it is different than the first option.
 void Parser::diagnoseConsecutiveIDs(StringRef First, SourceLoc FirstLoc,
@@ -4135,8 +4095,9 @@ parseDeclTypeAlias(Parser::ParseDeclOptions Flags, DeclAttributes &Attributes) {
   SourceLoc IdLoc;
   ParserStatus Status;
 
-  Status |= parseIdentifierDeclName(*this, Id, IdLoc, "typealias",
-                                    tok::colon, tok::equal);
+  Status |= parseIdentifierDeclName(
+      *this, Id, IdLoc, "typealias",
+      [](const Token &next) { return next.isAny(tok::colon, tok::equal); });
   if (Status.isError()) {
     TmpCtxt->setTransparent();
     return nullptr;
@@ -4250,9 +4211,10 @@ ParserResult<TypeDecl> Parser::parseDeclAssociatedType(Parser::ParseDeclOptions
   } else {
     AssociatedTypeLoc = consumeToken(tok::kw_associatedtype);
   }
-  
-  Status = parseIdentifierDeclName(*this, Id, IdLoc, "associatedtype",
-                                   tok::colon, tok::equal);
+
+  Status = parseIdentifierDeclName(
+      *this, Id, IdLoc, "associatedtype",
+      [](const Token &next) { return next.isAny(tok::colon, tok::equal); });
   if (Status.isError())
     return nullptr;
 
@@ -5473,8 +5435,10 @@ ParserResult<FuncDecl> Parser::parseDeclFunc(SourceLoc StaticLoc,
     // because we're aggressive about recovering/providing good diagnostics for
     // beginners.
     auto NameStatus = parseIdentifierDeclName(
-        *this, SimpleName, NameLoc, "function", tok::l_paren, tok::arrow,
-        tok::l_brace, TokenProperty::StartsWithLess);
+        *this, SimpleName, NameLoc, "function", [&](const Token &next) {
+          return next.isAny(tok::l_paren, tok::arrow, tok::l_brace) ||
+                 startsWithLess(next);
+        });
     if (NameStatus.isError())
       return nullptr;
   }
@@ -5717,9 +5681,10 @@ ParserResult<EnumDecl> Parser::parseDeclEnum(ParseDeclOptions Flags,
   SourceLoc EnumNameLoc;
   ParserStatus Status;
 
-  Status |= parseIdentifierDeclName(*this, EnumName, EnumNameLoc, "enum",
-                                    tok::colon, tok::l_brace,
-                                    TokenProperty::StartsWithLess);
+  Status |= parseIdentifierDeclName(
+      *this, EnumName, EnumNameLoc, "enum", [&](const Token &next) {
+        return next.isAny(tok::colon, tok::l_brace) || startsWithLess(next);
+      });
   if (Status.isError())
     return nullptr;
 
@@ -5823,9 +5788,11 @@ Parser::parseDeclEnumCase(ParseDeclOptions Flags,
     }
 
     if (Tok.is(tok::identifier)) {
-      Status |= parseIdentifierDeclName(*this, Name, NameLoc, "enum 'case'",
-                                        tok::l_paren, tok::kw_case, tok::colon,
-                                        tok::r_brace);
+      Status |= parseIdentifierDeclName(
+          *this, Name, NameLoc, "enum 'case'", [](const Token &next) {
+            return next.isAny(tok::l_paren, tok::kw_case, tok::colon,
+                              tok::r_brace);
+          });
       assert(Status.isSuccess());
       if (DotLoc.isValid())
         diagnose(DotLoc, diag::enum_case_dot_prefix)
@@ -5997,9 +5964,10 @@ ParserResult<StructDecl> Parser::parseDeclStruct(ParseDeclOptions Flags,
   SourceLoc StructNameLoc;
   ParserStatus Status;
 
-  Status |= parseIdentifierDeclName(*this, StructName, StructNameLoc, "struct",
-                                    tok::colon, tok::l_brace,
-                                    TokenProperty::StartsWithLess);
+  Status |= parseIdentifierDeclName(
+      *this, StructName, StructNameLoc, "struct", [&](const Token &next) {
+        return next.isAny(tok::colon, tok::l_brace) || startsWithLess(next);
+      });
   if (Status.isError())
     return nullptr;
 
@@ -6088,9 +6056,10 @@ ParserResult<ClassDecl> Parser::parseDeclClass(ParseDeclOptions Flags,
   SourceLoc ClassNameLoc;
   ParserStatus Status;
 
-  Status |= parseIdentifierDeclName(*this, ClassName, ClassNameLoc, "class",
-                                    tok::colon, tok::l_brace,
-                                    TokenProperty::StartsWithLess);
+  Status |= parseIdentifierDeclName(
+      *this, ClassName, ClassNameLoc, "class", [&](const Token &next) {
+        return next.isAny(tok::colon, tok::l_brace) || startsWithLess(next);
+      });
   if (Status.isError())
     return nullptr;
 
@@ -6207,8 +6176,9 @@ parseDeclProtocol(ParseDeclOptions Flags, DeclAttributes &Attributes) {
   Identifier ProtocolName;
   ParserStatus Status;
 
-  Status |= parseIdentifierDeclName(*this, ProtocolName, NameLoc, "protocol",
-                                    tok::colon, tok::l_brace);
+  Status |= parseIdentifierDeclName(
+      *this, ProtocolName, NameLoc, "protocol",
+      [&](const Token &next) { return next.isAny(tok::colon, tok::l_brace); });
   if (Status.isError())
     return nullptr;