[clang] ad16268 - [Clang] Do not check for underscores in isAllowedInitiallyIDChar

[Corentin Jabot via cfe-commits]

Author: Corentin Jabot
Date: 2022-07-29T17:46:38+02:00
New Revision: ad16268f135001bd21a805ae8acf8d8243793984

URL: https://github.com/llvm/llvm-project/commit/ad16268f135001bd21a805ae8acf8d8243793984
DIFF: https://github.com/llvm/llvm-project/commit/ad16268f135001bd21a805ae8acf8d8243793984.diff

LOG: [Clang] Do not check for underscores in isAllowedInitiallyIDChar

isAllowedInitiallyIDChar is only used with non-ASCII codepoints,
which are handled by isAsciiIdentifierStart.
To make that clearer, remove the check for _ from
isAllowedInitiallyIDChar, and assert on ASCII - to ensure neither
_ or $ are passed to this function.

Reviewed By: tahonermann, aaron.ballman

Differential Revision: https://reviews.llvm.org/D130750

Added: 
    

Modified: 
    clang/lib/Lex/Lexer.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp
index a4cff403e739c..6c1c55fc703fc 100644
--- a/clang/lib/Lex/Lexer.cpp
+++ b/clang/lib/Lex/Lexer.cpp
@@ -1483,13 +1483,13 @@ static bool isAllowedIDChar(uint32_t C, const LangOptions &LangOpts) {
 }
 
 static bool isAllowedInitiallyIDChar(uint32_t C, const LangOptions &LangOpts) {
+  assert(C > 0x7F && "isAllowedInitiallyIDChar called with an ASCII codepoint");
   if (LangOpts.AsmPreprocessor) {
     return false;
   }
   if (LangOpts.CPlusPlus || LangOpts.C2x) {
     static const llvm::sys::UnicodeCharSet XIDStartChars(XIDStartRanges);
-    // '_' doesn't have the XID_Start property but is allowed in C++.
-    return C == '_' || XIDStartChars.contains(C);
+    return XIDStartChars.contains(C);
   }
   if (!isAllowedIDChar(C, LangOpts))
     return false;