[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 +564,205 @@ 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;
+}
+
+std::vector<Range> findAllSelectorPieces(llvm::ArrayRef<syntax::Token> Tokens,
+                                         const SourceManager &SM, Selector Sel,
+                                         tok::TokenKind Terminator) {
+
+  unsigned NumArgs = Sel.getNumArgs();
+  llvm::SmallVector<tok::TokenKind, 8> Closes;
+  std::vector<Range> SelectorPieces;
+  unsigned Last = Tokens.size() - 1;
+  for (unsigned Index = 0; Index < Last; ++Index) {
+    const auto &Tok = Tokens[Index];
+
+    if (Closes.empty()) {
+      auto PieceCount = SelectorPieces.size();
+      if (PieceCount < NumArgs &&
+          isMatchingSelectorName(Tok, Tokens[Index + 1], SM,
+                                 Sel.getNameForSlot(PieceCount))) {
+        // If 'foo:' instead of ':' (empty selector), we need to skip the ':'
+        // token after the name.
+        if (!Sel.getNameForSlot(PieceCount).empty()) {
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kadircet wrote:

nit: braces

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