[clang][DependencyScanning] Use OverlayFS naming consistently

[naveen-seth]

Improves the readability of getFirstCC1CommandLine() by using consistent naming and adding documentation.
(This addresses the feedback in #169964 (comment))

[llvmbot]

@llvm/pr-subscribers-clang

Author: Naveen Seth Hanig (naveen-seth)

Changes

Improves the readability of getFirstCC1CommandLine() by using consistent naming and adding documentation.
(This addresses the feedback in #169964 (comment))

---

Full diff: https://github.com/llvm/llvm-project/pull/172352.diff

1 Files Affected:

• (modified) clang/lib/Tooling/DependencyScanningTool.cpp (+5-2)

diff --git a/clang/lib/Tooling/DependencyScanningTool.cpp b/clang/lib/Tooling/DependencyScanningTool.cpp
index 74cc6af3551f8..87f756d2f4df4 100644
--- a/clang/lib/Tooling/DependencyScanningTool.cpp
+++ b/clang/lib/Tooling/DependencyScanningTool.cpp
@@ -189,15 +189,18 @@ buildCC1CommandLine(const driver::Command &Cmd) {
   return Out;
 }
 
+/// Builds the compilation for the given driver command line and returns the
+/// first -cc1 command line, or std::nullopt on error, with diagnostics
+/// reported to \c Diags.
 static std::optional<std::vector<std::string>> getFirstCC1CommandLine(
     ArrayRef<std::string> CommandLine, DiagnosticsEngine &Diags,
-    llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> ScanFS) {
+    llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFS) {
   // Compilation holds a non-owning a reference to the Driver, hence we need to
   // keep the Driver alive when we use Compilation. Arguments to commands may be
   // owned by Alloc when expanded from response files.
   llvm::BumpPtrAllocator Alloc;
   const auto [Driver, Compilation] =
-      buildCompilation(CommandLine, Diags, ScanFS, Alloc);
+      buildCompilation(CommandLine, Diags, OverlayFS, Alloc);
   if (!Compilation)
     return std::nullopt;