[Clang][NFC] Avoid repeating copy of std::string in lambda implementation #153863
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…tion Static analysis flagged this code because it will cause unneeded copies of std::string. This fix is merely to use const auto & in the trailing return type.
shafik
requested review from
AaronBallman,
cor3ntin,
naveen-seth and
tahonermann
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@llvm/pr-subscribers-clang Author: Shafik Yaghmour (shafik) ChangesStatic analysis flagged this code because it will cause unneeded copies of std::string. This fix is merely to use const auto & in the trailing return type. Full diff: https://github.com/llvm/llvm-project/pull/153863.diff 1 Files Affected:
diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
index c3601a4e73e1f..81177a04654bb 100644
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
@@ -205,7 +205,7 @@ class FullDependencyConsumer : public DependencyConsumer {
std::vector<P1689ModuleInfo> Requires) override {
ModuleName = Provided ? Provided->ModuleName : "";
llvm::transform(Requires, std::back_inserter(NamedModuleDeps),
- [](const auto &Module) { return Module.ModuleName; });
+ [](const auto &Module) -> const auto & { return Module.ModuleName; });
}
TranslationUnitDeps takeTranslationUnitDeps();
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✅ With the latest revision this PR passed the C/C++ code formatter. |
| [](const auto &Module) { return Module.ModuleName; }); | ||
| llvm::transform( | ||
| Requires, std::back_inserter(NamedModuleDeps), | ||
| [](const auto &Module) -> const auto & { return Module.ModuleName; }); |
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Ultimately, you're doing a copy either way: you're inserting a string into an std::vector<std::string>. At best this saves a move constructor call.
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Static analysis flagged this code because it will cause unneeded copies of std::string. This fix is merely to use const auto & in the trailing return type.