Simplify the scheme used for keywords, and change the classification

scheme to be more useful.

The new scheme introduces a set of categories that should be more 
readable, and also reflects what we want to consider as an extension 
more accurately.  Specifically, it makes the "what is a keyword" 
determination accurately reflect whether the keyword is a GNU or 
Microsoft extension.

I also introduced separate flags for keyword aliases; this is useful 
because the classification of the aliases is mostly unrelated to the 
classification of the original keyword.

This patch treats anything that's in the implementation 
namespace (prefixed with "__", or "_X" where "X" is any upper-case 
letter) as a keyword without marking it as an extension.  This is 
consistent with the standards in that an implementation is allowed to define 
arbitrary extensions in the implementation namespace without violating 
the standard. This gets rid of all the nasty "extension used" warnings 
for stuff like __attribute__ in -pedantic mode.  We still warn for 
extensions outside of the the implementation namespace, like typeof.
If someone wants to implement -Wextensions or something like that, we 
could add additional information to the keyword table.

This also removes processing for the unused "Boolean" language option; 
such an extension isn't supported on any other C implementation, so I 
don't see any point to adding it.

The changes to test/CodeGen/inline.c are required because previously, we 
weren't actually disabling the "inline" keyword in -std=c89 mode.

I'll remove Boolean and NoExtensions from LangOptions in a follow-up 
commit.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70281 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 55 deletions

diff --git a/lib/Basic/IdentifierTable.cpp b/lib/Basic/IdentifierTable.cpp
index 69ee090b6e..cf78da9869 100644
--- a/lib/Basic/IdentifierTable.cpp
+++ b/lib/Basic/IdentifierTable.cpp
@@ -58,6 +58,18 @@ IdentifierTable::IdentifierTable(const LangOptions &LangOpts,
 // Language Keyword Implementation
 //===----------------------------------------------------------------------===//
 
+// Constants for TokenKinds.def
+namespace {
+  enum {
+    KEYALL = 1,
+    KEYC99 = 2,
+    KEYCXX = 4,
+    KEYCXX0X = 8,
+    KEYGNU = 16,
+    KEYMS = 32
+  };
+}
+
 /// AddKeyword - This method is used to associate a token ID with specific
 /// identifiers because they are language keywords.  This causes the lexer to
 /// automatically map matching identifiers to specialized token codes.
@@ -67,40 +79,24 @@ IdentifierTable::IdentifierTable(const LangOptions &LangOpts,
 /// in the specified language, and set to 2 if disabled in the
 /// specified language.
 static void AddKeyword(const char *Keyword, unsigned KWLen,
-                       tok::TokenKind TokenCode,
-                       int C90, int C99, int CXX, int CXX0x, int BoolSupport,
+                       tok::TokenKind TokenCode, unsigned Flags,
                        const LangOptions &LangOpts, IdentifierTable &Table) {
-  int Flags = 0;
-  if (BoolSupport != 0) {
-    Flags = LangOpts.CPlusPlus? 0 : LangOpts.Boolean ? BoolSupport : 2;
-  } else if (LangOpts.CPlusPlus) {
-    Flags = LangOpts.CPlusPlus0x ? CXX0x : CXX;
-  } else if (LangOpts.C99) {
-    Flags = C99;
-  } else {
-    Flags = C90;
-  }
-  
-  // Don't add this keyword if disabled in this language or if an extension
-  // and extensions are disabled.
-  if (Flags + LangOpts.NoExtensions >= 2) return;
-  
+  unsigned AddResult = 0;
+  if (Flags & KEYALL) AddResult = 2;
+  else if (LangOpts.CPlusPlus && (Flags & KEYCXX)) AddResult = 2;
+  else if (LangOpts.CPlusPlus0x && (Flags & KEYCXX0X)) AddResult = 2;
+  else if (LangOpts.C99 && (Flags & KEYC99)) AddResult = 2;
+  else if (LangOpts.GNUMode && (Flags & KEYGNU)) AddResult = 1;
+  else if (LangOpts.Microsoft && (Flags & KEYMS)) AddResult = 1;
+
+  // Don't add this keyword if disabled in this language.
+  if (AddResult == 0) return;
+
   IdentifierInfo &Info = Table.get(Keyword, Keyword+KWLen);
   Info.setTokenID(TokenCode);
-  Info.setIsExtensionToken(Flags == 1);
+  Info.setIsExtensionToken(AddResult == 1);
 }
 
-static void AddAlias(const char *Keyword, unsigned KWLen,
-                     tok::TokenKind AliaseeID,
-                     const char *AliaseeKeyword, unsigned AliaseeKWLen,
-                     const LangOptions &LangOpts, IdentifierTable &Table) {
-  IdentifierInfo &AliasInfo = Table.get(Keyword, Keyword+KWLen);
-  IdentifierInfo &AliaseeInfo = Table.get(AliaseeKeyword,
-                                          AliaseeKeyword+AliaseeKWLen);
-  AliasInfo.setTokenID(AliaseeID);
-  AliasInfo.setIsExtensionToken(AliaseeInfo.isExtensionToken());
-}  
-
 /// AddCXXOperatorKeyword - Register a C++ operator keyword alternative
 /// representations.
 static void AddCXXOperatorKeyword(const char *Keyword, unsigned KWLen,
@@ -122,35 +118,13 @@ static void AddObjCKeyword(tok::ObjCKeywordKind ObjCID,
 /// AddKeywords - Add all keywords to the symbol table.
 ///
 void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
-  enum {
-    C90Shift = 0,
-    EXTC90   = 1 << C90Shift,
-    NOTC90   = 2 << C90Shift,
-    C99Shift = 2,
-    EXTC99   = 1 << C99Shift,
-    NOTC99   = 2 << C99Shift,
-    CPPShift = 4,
-    EXTCPP   = 1 << CPPShift,
-    NOTCPP   = 2 << CPPShift,
-    CPP0xShift = 6,
-    EXTCPP0x   = 1 << CPP0xShift,
-    NOTCPP0x   = 2 << CPP0xShift,
-    BoolShift = 8,
-    BOOLSUPPORT = 1 << BoolShift,
-    Mask     = 3
-  };
-  
   // Add keywords and tokens for the current language.
 #define KEYWORD(NAME, FLAGS) \
   AddKeyword(#NAME, strlen(#NAME), tok::kw_ ## NAME,  \
-             ((FLAGS) >> C90Shift) & Mask, \
-             ((FLAGS) >> C99Shift) & Mask, \
-             ((FLAGS) >> CPPShift) & Mask, \
-             ((FLAGS) >> CPP0xShift) & Mask, \
-             ((FLAGS) >> BoolShift) & Mask, LangOpts, *this);
-#define ALIAS(NAME, TOK) \
-  AddAlias(NAME, strlen(NAME), tok::kw_ ## TOK, #TOK, strlen(#TOK),  \
-           LangOpts, *this);
+             FLAGS, LangOpts, *this);
+#define ALIAS(NAME, TOK, FLAGS) \
+  AddKeyword(NAME, strlen(NAME), tok::kw_ ## TOK,  \
+             FLAGS, LangOpts, *this);
 #define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \
   if (LangOpts.CXXOperatorNames)          \
     AddCXXOperatorKeyword(#NAME, strlen(#NAME), tok::ALIAS, *this);