Update the Pass→std::move() tool to handle nested calls to Pass().

tools/clang/pass_to_move/PassToMove.cpp

Index: tools/clang/pass_to_move/PassToMove.cpp
diff --git a/tools/clang/pass_to_move/PassToMove.cpp b/tools/clang/pass_to_move/PassToMove.cpp
index 2fd947c4ed61d50fe55606de277e23a6b0f84254..c5858f453500c0b72031dc58acdd93416ea1797e 100644
--- a/tools/clang/pass_to_move/PassToMove.cpp
+++ b/tools/clang/pass_to_move/PassToMove.cpp
@@ -41,26 +41,30 @@ class RewriterCallback : public MatchFinder::MatchCallback {
 void RewriterCallback::run(const MatchFinder::MatchResult& result) {
   const clang::CXXMemberCallExpr* call_expr =
       result.Nodes.getNodeAs<clang::CXXMemberCallExpr>("expr");
-  const bool is_arrow =
-      clang::dyn_cast<clang::MemberExpr>(call_expr->getCallee())->isArrow();
+  const clang::MemberExpr* callee =
+      clang::dyn_cast<clang::MemberExpr>(call_expr->getCallee());
+  const bool is_arrow = callee->isArrow();
   const clang::Expr* arg = result.Nodes.getNodeAs<clang::Expr>("arg");
 
-  clang::CharSourceRange arg_range = clang::CharSourceRange::getTokenRange(
-      result.SourceManager->getSpellingLoc(arg->getLocStart()),
-      result.SourceManager->getSpellingLoc(arg->getLocEnd()));
-  std::string new_source_text = "std::move(";
-  if (is_arrow)
-    new_source_text += "*";
-  llvm::StringRef arg_text = clang::Lexer::getSourceText(
-      arg_range, *result.SourceManager, result.Context->getLangOpts());
-  new_source_text.append(arg_text.data(), arg_text.size());
-  new_source_text += ")";
-
-  // Replace the entire original expression with std::move(arg).
-  clang::CharSourceRange expr_range = clang::CharSourceRange::getTokenRange(
-      result.SourceManager->getSpellingLoc(call_expr->getLocStart()),
-      result.SourceManager->getSpellingLoc(call_expr->getLocEnd()));
-  replacements_->emplace(*result.SourceManager, expr_range, new_source_text);
+  const char kMoveRefText[] = "std::move(";
+  const char kMovePtrText[] = "std::move(*";
+
+  replacements_->emplace(*result.SourceManager,
+                         result.SourceManager->getSpellingLoc(
+                             arg->getLocStart()),
+                         0,
+                         is_arrow ? kMovePtrText : kMoveRefText);
+
+  // Delete everything but the closing parentheses from the original call to
+  // Pass(): the closing parantheses is left to match up with the parantheses
+  // just inserted with std::move.
+  replacements_->emplace(*result.SourceManager,
+                         clang::CharSourceRange::getCharRange(
+                             result.SourceManager->getSpellingLoc(
+                                 callee->getOperatorLoc()),
+                             result.SourceManager->getSpellingLoc(
+                                 call_expr->getRParenLoc())),
+                         "");
 }
 
 }  // namespace