[clang] Refactor clang's keyword enable/disable mechanism to allow lldb to re-use it

lldb's CPlusPlusNameParser is currently identifying keywords using it's own
map implemented using clang/Basic/TokenKinds.def. However, it does not respect
the language options so identifiers can incorrectly determined to be keywords
when using languages in which they are not keywords.

Rather than implement the logic to enable/disable keywords in both projects it
makes sense for lldb to use clang's implementation.

See #164284 for more information

Author: dsandersllvm

clang/include/clang/Basic/IdentifierTable.h

@@ -46,6 +46,55 @@ class LangOptions;
 class MultiKeywordSelector;
 class SourceLocation;
 
+enum TokenKey : unsigned {
+  KEYC99 = 0x1,
+  KEYCXX = 0x2,
+  KEYCXX11 = 0x4,
+  KEYGNU = 0x8,
+  KEYMS = 0x10,
+  BOOLSUPPORT = 0x20,
+  KEYALTIVEC = 0x40,
+  KEYNOCXX = 0x80,
+  KEYBORLAND = 0x100,
+  KEYOPENCLC = 0x200,
+  KEYC23 = 0x400,
+  KEYNOMS18 = 0x800,
+  KEYNOOPENCL = 0x1000,
+  WCHARSUPPORT = 0x2000,
+  HALFSUPPORT = 0x4000,
+  CHAR8SUPPORT = 0x8000,
+  KEYOBJC = 0x10000,
+  KEYZVECTOR = 0x20000,
+  KEYCOROUTINES = 0x40000,
+  KEYMODULES = 0x80000,
+  KEYCXX20 = 0x100000,
+  KEYOPENCLCXX = 0x200000,
+  KEYMSCOMPAT = 0x400000,
+  KEYSYCL = 0x800000,
+  KEYCUDA = 0x1000000,
+  KEYZOS = 0x2000000,
+  KEYNOZOS = 0x4000000,
+  KEYHLSL = 0x8000000,
+  KEYFIXEDPOINT = 0x10000000,
+  KEYMAX = KEYFIXEDPOINT, // The maximum key
+  KEYALLCXX = KEYCXX | KEYCXX11 | KEYCXX20,
+  KEYALL = (KEYMAX | (KEYMAX - 1)) & ~KEYNOMS18 & ~KEYNOOPENCL &
+           ~KEYNOZOS // KEYNOMS18, KEYNOOPENCL, KEYNOZOS are excluded.
+};
+
+/// How a keyword is treated in the selected standard. This enum is ordered
+/// intentionally so that the value that 'wins' is the most 'permissive'.
+enum KeywordStatus {
+  KS_Unknown,   // Not yet calculated. Used when figuring out the status.
+  KS_Disabled,  // Disabled
+  KS_Future,    // Is a keyword in future standard
+  KS_Extension, // Is an extension
+  KS_Enabled,   // Enabled
+};
+
+KeywordStatus getKeywordStatus(const LangOptions &LangOpts,
+                               unsigned Flags);
+
 enum class ReservedIdentifierStatus {
   NotReserved = 0,
   StartsWithUnderscoreAtGlobalScope,

clang/lib/Basic/IdentifierTable.cpp

@@ -77,57 +77,6 @@ IdentifierTable::IdentifierTable(const LangOptions &LangOpts,
 // Language Keyword Implementation
 //===----------------------------------------------------------------------===//
 
-// Constants for TokenKinds.def
-namespace {
-
-enum TokenKey : unsigned {
-  KEYC99 = 0x1,
-  KEYCXX = 0x2,
-  KEYCXX11 = 0x4,
-  KEYGNU = 0x8,
-  KEYMS = 0x10,
-  BOOLSUPPORT = 0x20,
-  KEYALTIVEC = 0x40,
-  KEYNOCXX = 0x80,
-  KEYBORLAND = 0x100,
-  KEYOPENCLC = 0x200,
-  KEYC23 = 0x400,
-  KEYNOMS18 = 0x800,
-  KEYNOOPENCL = 0x1000,
-  WCHARSUPPORT = 0x2000,
-  HALFSUPPORT = 0x4000,
-  CHAR8SUPPORT = 0x8000,
-  KEYOBJC = 0x10000,
-  KEYZVECTOR = 0x20000,
-  KEYCOROUTINES = 0x40000,
-  KEYMODULES = 0x80000,
-  KEYCXX20 = 0x100000,
-  KEYOPENCLCXX = 0x200000,
-  KEYMSCOMPAT = 0x400000,
-  KEYSYCL = 0x800000,
-  KEYCUDA = 0x1000000,
-  KEYZOS = 0x2000000,
-  KEYNOZOS = 0x4000000,
-  KEYHLSL = 0x8000000,
-  KEYFIXEDPOINT = 0x10000000,
-  KEYMAX = KEYFIXEDPOINT, // The maximum key
-  KEYALLCXX = KEYCXX | KEYCXX11 | KEYCXX20,
-  KEYALL = (KEYMAX | (KEYMAX - 1)) & ~KEYNOMS18 & ~KEYNOOPENCL &
-           ~KEYNOZOS // KEYNOMS18, KEYNOOPENCL, KEYNOZOS are excluded.
-};
-
-/// How a keyword is treated in the selected standard. This enum is ordered
-/// intentionally so that the value that 'wins' is the most 'permissive'.
-enum KeywordStatus {
-  KS_Unknown,   // Not yet calculated. Used when figuring out the status.
-  KS_Disabled,  // Disabled
-  KS_Future,    // Is a keyword in future standard
-  KS_Extension, // Is an extension
-  KS_Enabled,   // Enabled
-};
-
-} // namespace
-
 // This works on a single TokenKey flag and checks the LangOpts to get the
 // KeywordStatus based exclusively on this flag, so that it can be merged in
 // getKeywordStatus. Most should be enabled/disabled, but some might imply
@@ -222,7 +171,7 @@ static KeywordStatus getKeywordStatusHelper(const LangOptions &LangOpts,
 
 /// Translates flags as specified in TokenKinds.def into keyword status
 /// in the given language standard.
-static KeywordStatus getKeywordStatus(const LangOptions &LangOpts,
+KeywordStatus clang::getKeywordStatus(const LangOptions &LangOpts,
                                       unsigned Flags) {
   // KEYALL means always enabled, so special case this one.
   if (Flags == KEYALL) return KS_Enabled;