[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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@@ -543,6 +550,45 @@ std::optional<InvalidName> checkName(const NamedDecl &RenameDecl,
   return Result;
 }
 
+clangd::Range tokenRangeForLoc(ParsedAST &AST, SourceLocation TokLoc,
+                               const SourceManager &SM,
+                               const LangOptions &LangOpts) {
+  const auto *Token = AST.getTokens().spelledTokenAt(TokLoc);
+  assert(Token && "got inclusion at wrong offset");
+  clangd::Range Result;
+  Result.start = sourceLocToPosition(SM, Token->location());
+  Result.end = sourceLocToPosition(SM, Token->endLocation());
+  return Result;
+}
+
+// AST-based ObjC method rename, it renames all occurrences in the main file
+// even for selectors which may have multiple tokens.
+llvm::Expected<tooling::Replacements>
+renameObjCMethodWithinFile(ParsedAST &AST, const ObjCMethodDecl *MD,
+                           llvm::StringRef NewName,
+                           std::vector<SourceLocation> Locs) {
+  const SourceManager &SM = AST.getSourceManager();
+  auto Code = SM.getBufferData(SM.getMainFileID());
+  auto RenameIdentifier = MD->getSelector().getNameForSlot(0).str();
+  llvm::SmallVector<llvm::StringRef, 8> NewNames;
+  NewName.split(NewNames, ":");
+  if (NewNames.empty())
+    NewNames.push_back(NewName);
+
+  std::vector<Range> Ranges;
+  const auto &LangOpts = MD->getASTContext().getLangOpts();
+  for (const auto &Loc : Locs)
+    Ranges.push_back(tokenRangeForLoc(AST, Loc, SM, LangOpts));
+  auto FilePath = AST.tuPath();
+  auto RenameRanges = collectRenameIdentifierRanges(
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kadircet wrote:

hmm we don't re-use the `Ranges`/`Locs` here at all. let's strip it all (or use it to guide lexing, instead of searching for selector identifier, just check if selectors at these locations are what we need ?)

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