-Make TokenID of IdentifierInfo read-only, remove setTokenID().

-There are 2 instances that change the TokenID for GNU libstdc++ 4.2 compatibility.
  To handler those cases introduce a RevertedTokenID bitfield, RevertTokenIDToIdentifier() and hasRevertedTokenIDToIdentifier() methods.
  Store the bitfield in PCH.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@110868 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 11 insertions, 7 deletions

diff --git a/lib/Basic/IdentifierTable.cpp b/lib/Basic/IdentifierTable.cpp
index 1f0c52bdc1..c7b16c99c9 100644
--- a/lib/Basic/IdentifierTable.cpp
+++ b/lib/Basic/IdentifierTable.cpp
@@ -35,6 +35,7 @@ IdentifierInfo::IdentifierInfo() {
   IsCPPOperatorKeyword = false;
   NeedsHandleIdentifier = false;
   IsFromPCH = false;
+  RevertedTokenID = false;
   FETokenInfo = 0;
   Entry = 0;
 }
@@ -101,8 +102,7 @@ static void AddKeyword(llvm::StringRef Keyword,
   // Don't add this keyword if disabled in this language.
   if (AddResult == 0) return;
 
-  IdentifierInfo &Info = Table.get(Keyword);
-  Info.setTokenID(TokenCode);
+  IdentifierInfo &Info = Table.get(Keyword, TokenCode);
   Info.setIsExtensionToken(AddResult == 1);
 }
 
@@ -111,8 +111,7 @@ static void AddKeyword(llvm::StringRef Keyword,
 static void AddCXXOperatorKeyword(llvm::StringRef Keyword,
                                   tok::TokenKind TokenCode,
                                   IdentifierTable &Table) {
-  IdentifierInfo &Info = Table.get(Keyword);
-  Info.setTokenID(TokenCode);
+  IdentifierInfo &Info = Table.get(Keyword, TokenCode);
   Info.setIsCPlusPlusOperatorKeyword();
 }
 
diff --git a/lib/Frontend/PCHReader.cpp b/lib/Frontend/PCHReader.cpp
index 68acbb2faf..a09b89deea 100644
--- a/lib/Frontend/PCHReader.cpp
+++ b/lib/Frontend/PCHReader.cpp
@@ -657,6 +657,8 @@ public:
     unsigned Bits = ReadUnalignedLE16(d);
     bool CPlusPlusOperatorKeyword = Bits & 0x01;
     Bits >>= 1;
+    bool HasRevertedTokenIDToIdentifier = Bits & 0x01;
+    Bits >>= 1;
     bool Poisoned = Bits & 0x01;
     Bits >>= 1;
     bool ExtensionToken = Bits & 0x01;
@@ -677,7 +679,9 @@ public:
     Reader.SetIdentifierInfo(ID, II);
 
     // Set or check the various bits in the IdentifierInfo structure.
-    // FIXME: Load token IDs lazily, too?
+    // Token IDs are read-only.
+    if (HasRevertedTokenIDToIdentifier)
+      II->RevertTokenIDToIdentifier();
     II->setObjCOrBuiltinID(ObjCOrBuiltinID);
     assert(II->isExtensionToken() == ExtensionToken &&
            "Incorrect extension token flag");
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 0eed4ccd71..6712122682 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -1847,6 +1847,7 @@ public:
     Bits = (Bits << 1) | unsigned(hasMacroDefinition);
     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
     Bits = (Bits << 1) | unsigned(II->isPoisoned());
+    Bits = (Bits << 1) | unsigned(II->hasRevertedTokenIDToIdentifier());
     Bits = (Bits << 1) | unsigned(II->isCPlusPlusOperatorKeyword());
     clang::io::Emit16(Out, Bits);
 
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index 55e677dbaa..5f404ac430 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -661,7 +661,7 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
     // token sequence "struct __is_pod", make __is_pod into a normal
     // identifier rather than a keyword, to allow libstdc++ 4.2 to work
     // properly.
-    Tok.getIdentifierInfo()->setTokenID(tok::identifier);
+    Tok.getIdentifierInfo()->RevertTokenIDToIdentifier();
     Tok.setKind(tok::identifier);
   }
 
@@ -671,7 +671,7 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
     // token sequence "struct __is_empty", make __is_empty into a normal
     // identifier rather than a keyword, to allow libstdc++ 4.2 to work
     // properly.
-    Tok.getIdentifierInfo()->setTokenID(tok::identifier);
+    Tok.getIdentifierInfo()->RevertTokenIDToIdentifier();
     Tok.setKind(tok::identifier);
   }