[clang-tools-extra] Add support for renaming objc methods, even those with multiple selector pieces (PR #76466)

[kadir çetinkaya via cfe-commits]

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@@ -538,11 +564,222 @@ std::optional<InvalidName> checkName(const NamedDecl &RenameDecl,
             Conflict->getLocation().printToString(ASTCtx.getSourceManager())};
     }
   }
-  if (Result)
+  if (Result) {
     InvalidNameMetric.record(1, toString(Result->K));
+    return makeError(*Result);
+  }
+  return llvm::Error::success();
+}
+
+bool isSelectorLike(const syntax::Token &Cur, const syntax::Token &Next) {
+  return Cur.kind() == tok::identifier && Next.kind() == tok::colon &&
+         // We require the selector name and : to be contiguous.
+         // e.g. support `foo:` but not `foo :`.
+         Cur.endLocation() == Next.location();
+}
+
+bool isMatchingSelectorName(const syntax::Token &Cur, const syntax::Token &Next,
+                            const SourceManager &SM,
+                            llvm::StringRef SelectorName) {
+  if (SelectorName.empty())
+    return Cur.kind() == tok::colon;
+  return isSelectorLike(Cur, Next) && Cur.text(SM) == SelectorName;
+}
+
+// Scan through Tokens to find ranges for each selector fragment in Sel at the
+// top level (not nested in any () or {} or []). The search will terminate upon
+// seeing Terminator or a ; at the top level.
+std::optional<SymbolRange>
+findAllSelectorPieces(llvm::ArrayRef<syntax::Token> Tokens,
+                      const SourceManager &SM, Selector Sel,
+                      tok::TokenKind Terminator) {
+
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kadircet wrote:

`assert(!Tokens.empty())`

https://github.com/llvm/llvm-project/pull/76466