[clang][transformer] Change name range-selector to return Error instead of an invalid range.

[yuhaouy]

Previously, when the text in selected range was different from the decl's name, name returned an invalid range, which could cause crashes if name was nested in other range selectors that assumed always valid ranges. With this change, name returns an Error if it can't get the range.

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[llvmbot]

@llvm/pr-subscribers-clang

Author: Yu Hao (yuhaouy)

Changes

Previously, when the text in selected range was different from the decl's name, name returned an invalid range, which could cause crashes if name was nested in other range selectors that assumed always valid ranges. With this change, name returns an Error if it can't get the range.

---

Full diff: https://github.com/llvm/llvm-project/pull/164715.diff

1 Files Affected:

• (modified) clang/lib/Tooling/Transformer/RangeSelector.cpp (+6-2)

diff --git a/clang/lib/Tooling/Transformer/RangeSelector.cpp b/clang/lib/Tooling/Transformer/RangeSelector.cpp
index 171c786bc366f..fbde6e4a2b914 100644
--- a/clang/lib/Tooling/Transformer/RangeSelector.cpp
+++ b/clang/lib/Tooling/Transformer/RangeSelector.cpp
@@ -205,8 +205,12 @@ RangeSelector transformer::name(std::string ID) {
       // `foo<int>` for which this range will be too short.  Doing so will
       // require subcasing `NamedDecl`, because it doesn't provide virtual
       // access to the \c DeclarationNameInfo.
-      if (tooling::getText(R, *Result.Context) != D->getName())
-        return CharSourceRange();
+      StringRef Text = tooling::getText(R, *Result.Context);
+      if (Text != D->getName())
+        return llvm::make_error<StringError>(
+            llvm::errc::not_supported,
+            "Failed to get the name range for the decl. Name is " +
+                D->getName() + ", but range is " + Text);
       return R;
     }
     if (const auto *E = Node.get<DeclRefExpr>()) {

[fmayer]

Looks reasonable

[ymand]

Thank you!

[ymand]

Actually -- are there any tests you can add/updated to reflect?

[yuhaouy]

Actually -- are there any tests you can add/updated to reflect?

Good point. I've only seen name failing for ranges in macro body. name works if the range is in macro arg.
Added tests for both macro body and args.

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