[clang] [clang] Add explicit std::move(...) to avoid a few copies (PR #180478)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: None (serge-sans-paille)

<details>
<summary>Changes</summary>

Moving an std::shared_ptr is always profitable (marginally).

Moving a clang::LayoutOverrideSource::Layout may be profitable depending on the size of the underlying llvm::SmallVector.

Changes suggested by performance-use-std-move from #<!-- -->179467

---
Full diff: https://github.com/llvm/llvm-project/pull/180478.diff


2 Files Affected:

- (modified) clang/lib/Frontend/ASTUnit.cpp (+1-1) 
- (modified) clang/lib/Frontend/LayoutOverrideSource.cpp (+1-1) 


``````````diff
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index ee22e16bc202d..60433fd7a2f39 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -1476,7 +1476,7 @@ ASTUnit::create(std::shared_ptr<CompilerInvocation> CI,
   ConfigureDiags(Diags, *AST, CaptureDiagnostics);
   IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS =
       createVFSFromCompilerInvocation(*CI, *Diags);
-  AST->DiagOpts = DiagOpts;
+  AST->DiagOpts = std::move(DiagOpts);
   AST->Diagnostics = Diags;
   AST->FileSystemOpts = CI->getFileSystemOpts();
   AST->Invocation = std::move(CI);
diff --git a/clang/lib/Frontend/LayoutOverrideSource.cpp b/clang/lib/Frontend/LayoutOverrideSource.cpp
index 0a60e00e5cb12..6912b9c112006 100644
--- a/clang/lib/Frontend/LayoutOverrideSource.cpp
+++ b/clang/lib/Frontend/LayoutOverrideSource.cpp
@@ -186,7 +186,7 @@ LayoutOverrideSource::LayoutOverrideSource(StringRef Filename) {
 
   // Flush the last type/layout, if there is one.
   if (!CurrentType.empty())
-    Layouts[CurrentType] = CurrentLayout;
+    Layouts[CurrentType] = std::move(CurrentLayout);
 }
 
 bool

``````````

</details>


https://github.com/llvm/llvm-project/pull/180478