[clang] [Clang][Preprocessor] Unify header-name lookahead for import and include (PR #191004)

[Richard Smith via cfe-commits]

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@@ -1356,32 +1356,32 @@ bool Preprocessor::HandleModuleContextualKeyword(Token &Result) {
   llvm::SaveAndRestore<bool> SavedParsingPreprocessorDirective(
       CurPPLexer->ParsingPreprocessorDirective, true);
 
-  // The next token may be an angled string literal after import keyword.
-  llvm::SaveAndRestore<bool> SavedParsingFilemame(
-      CurPPLexer->ParsingFilename,
-      Result.getIdentifierInfo()->isImportKeyword());
-
-  std::optional<Token> NextTok = peekNextPPToken();
-  if (!NextTok)
-    return false;
-
-  if (NextTok->is(tok::raw_identifier))
-    LookUpIdentifierInfo(*NextTok);
-
-  if (Result.getIdentifierInfo()->isImportKeyword()) {
-    if (NextTok->isOneOf(tok::identifier, tok::less, tok::colon,
-                         tok::header_name)) {
-      Result.setKind(tok::kw_import);
-      ModuleImportLoc = Result.getLocation();
-      return true;
+  if (II->isModuleKeyword()) {
+    if (auto NextTok = peekNextPPToken()) {
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zygoloid wrote:

I don't think we need peek for that, because we don't need to try lexing one way, then roll back and try again a different way if it fails. I think it would suffice to lex a token, then use `EnterToken` to push it back onto the token stream for processing after the `import` token.

https://github.com/llvm/llvm-project/pull/191004