[lld] [lld] Add explicit std::move(...) to avoid a few vector copies (PR #180474)

[via llvm-commits]

https://github.com/serge-sans-paille created https://github.com/llvm/llvm-project/pull/180474

In corner cases, it is profitable to move an llvm::SmallString instead of copying it.

It is almost always profitable to move an std::vector

Changes suggested by performance-use-std-move from https://github.com/llvm/llvm-project/pull/179467

>From 6baa408fb5a191a33d29ab88d6cc2323e9e461da Mon Sep 17 00:00:00 2001
From: serge-sans-paille <sguelton at mozilla.com>
Date: Mon, 9 Feb 2026 08:38:39 +0100
Subject: [PATCH] [lld] Add explicit std::move(...) to avoid a few vector
 copies

In corner cases, it is profitable to move an llvm::SmallString instead of
copying it.

It is almost always profitable to move an std::vector

Changes suggested by performance-use-std-move from https://github.com/llvm/llvm-project/pull/179467
---
 lld/COFF/Driver.cpp         | 2 +-
 lld/wasm/OutputSections.cpp | 2 +-
 lld/wasm/Writer.cpp         | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index 3bc9c98bcdbc3..699d53ca6d2e3 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -1339,7 +1339,7 @@ void LinkerDriver::parsePDBAltPath() {
     cursor = secondMark + 1;
   }
 
-  ctx.config.pdbAltPath = buf;
+  ctx.config.pdbAltPath = std::move(buf);
 }
 
 /// Convert resource files and potentially merge input resource object
diff --git a/lld/wasm/OutputSections.cpp b/lld/wasm/OutputSections.cpp
index 8ccd38f7895cb..d6348e459d31e 100644
--- a/lld/wasm/OutputSections.cpp
+++ b/lld/wasm/OutputSections.cpp
@@ -232,7 +232,7 @@ void CustomSection::finalizeInputSections() {
     return;
 
   mergedSection->finalizeContents();
-  inputSections = newSections;
+  inputSections = std::move(newSections);
 }
 
 void CustomSection::finalizeContents() {
diff --git a/lld/wasm/Writer.cpp b/lld/wasm/Writer.cpp
index a184cdbdfefa8..40a5832056087 100644
--- a/lld/wasm/Writer.cpp
+++ b/lld/wasm/Writer.cpp
@@ -1109,7 +1109,7 @@ void Writer::combineOutputSegments() {
     }
   }
 
-  segments = newSegments;
+  segments = std::move(newSegments);
 }
 
 static void createFunction(DefinedFunction *func, StringRef bodyContent) {