Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.

1 files changed, 7 insertions, 5 deletions

diff --git a/llvm/tools/llvm-xray/xray-graph-diff.cpp b/llvm/tools/llvm-xray/xray-graph-diff.cpp
index a1bca32..11210e2 100644
--- a/llvm/tools/llvm-xray/xray-graph-diff.cpp
+++ b/llvm/tools/llvm-xray/xray-graph-diff.cpp
@@ -314,7 +314,7 @@ static std::string getLabel(const GraphDiffRenderer::GraphT::EdgeValueType &E,
     const auto &RightStat = EdgeAttr.CorrEdgePtr[1]->second.S;
 
     double RelDiff = statRelDiff(LeftStat, RightStat, EL);
-    return formatv(R"({0:P})", RelDiff);
+    return std::string(formatv(R"({0:P})", RelDiff));
   }
 }
 
@@ -324,17 +324,19 @@ static std::string getLabel(const GraphDiffRenderer::GraphT::VertexValueType &V,
   const auto &VertexAttr = V.second;
   switch (VL) {
   case GraphDiffRenderer::StatType::NONE:
-    return formatv(R"({0})", truncateString(VertexId, TrunLen).str());
+    return std::string(
+        formatv(R"({0})", truncateString(VertexId, TrunLen).str()));
   default:
     if (containsNullptr(VertexAttr.CorrVertexPtr))
-      return formatv(R"({0})", truncateString(VertexId, TrunLen).str());
+      return std::string(
+          formatv(R"({0})", truncateString(VertexId, TrunLen).str()));
 
     const auto &LeftStat = VertexAttr.CorrVertexPtr[0]->second.S;
     const auto &RightStat = VertexAttr.CorrVertexPtr[1]->second.S;
 
     double RelDiff = statRelDiff(LeftStat, RightStat, VL);
-    return formatv(R"({{{0}|{1:P}})", truncateString(VertexId, TrunLen).str(),
-                   RelDiff);
+    return std::string(formatv(
+        R"({{{0}|{1:P}})", truncateString(VertexId, TrunLen).str(), RelDiff));
   }
 }