Simplify RevertibleTypeTraits as a form of contextual keyword

Now that we emit diagnostics for keyword-as-identifier hacks (-Wkeyword-compat)
we can go ahead and simplify some of the old revertible keyword support.

This commit adds a TryIdentKeywordUpgrade() function to mirror the recently
added TryKeywordIdentFallback() and uses it to replace the hard-coded list of
REVERTIBLE_TYPE_TRAITs.

llvm-svn: 197496

1 files changed, 11 insertions, 25 deletions

diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index b34b1119af9..2d6523cfe41 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -1180,31 +1180,17 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
   // C++11 attributes
   SourceLocation AttrFixitLoc = Tok.getLocation();
 
-  if (TagType == DeclSpec::TST_struct &&
-      !Tok.is(tok::identifier) &&
-      Tok.getIdentifierInfo() &&
-      (Tok.is(tok::kw___is_arithmetic) ||
-       Tok.is(tok::kw___is_convertible) ||
-       Tok.is(tok::kw___is_empty) ||
-       Tok.is(tok::kw___is_floating_point) ||
-       Tok.is(tok::kw___is_function) ||
-       Tok.is(tok::kw___is_fundamental) ||
-       Tok.is(tok::kw___is_integral) ||
-       Tok.is(tok::kw___is_member_function_pointer) ||
-       Tok.is(tok::kw___is_member_pointer) ||
-       Tok.is(tok::kw___is_pod) ||
-       Tok.is(tok::kw___is_pointer) ||
-       Tok.is(tok::kw___is_same) ||
-       Tok.is(tok::kw___is_scalar) ||
-       Tok.is(tok::kw___is_signed) ||
-       Tok.is(tok::kw___is_unsigned) ||
-       Tok.is(tok::kw___is_void)))
-    // GNU libstdc++ 4.2 and libc++ use certain intrinsic names as the
-    // name of struct templates, but some are keywords in GCC >= 4.3
-    // and Clang. Therefore, when we see the token sequence "struct
-    // X", make X into a normal identifier rather than a keyword, to
-    // allow libstdc++ 4.2 and libc++ to work properly.
-    TryKeywordIdentFallback(true);
+  // GNU libstdc++ and libc++ use certain intrinsic names as the
+  // name of struct templates, but some are keywords in GCC >= 4.3
+  // MSVC and Clang. For compatibility, convert the token to an identifier
+  // and issue a warning diagnostic.
+  if (TagType == DeclSpec::TST_struct && !Tok.is(tok::identifier) &&
+      !Tok.isAnnotation()) {
+    const IdentifierInfo *II = Tok.getIdentifierInfo();
+    // We rarely end up here so the following check is efficient.
+    if (II && II->getName().startswith("__is_"))
+      TryKeywordIdentFallback(true);
+  }
 
   // Parse the (optional) nested-name-specifier.
   CXXScopeSpec &SS = DS.getTypeSpecScope();