[lldb] Avoid FileSystem::Resolve for cached files in the SourceManager

Currently, source files are cached by their resolved path. This means
that before we can query the cache, we potentially have to resolve the
path, which can be slow. This patch avoids the call to FileSystem::Resolve
by caching both the resolved and unresolved path. We now only resolve
the path once when we create and cache a new file.

rdar://110787562

Differential revision: https://reviews.llvm.org/D153726

1 files changed, 3 insertions, 15 deletions

diff --git a/lldb/source/Host/common/FileSystem.cpp b/lldb/source/Host/common/FileSystem.cpp
index 1fe4e8f..52227a9 100644
--- a/lldb/source/Host/common/FileSystem.cpp
+++ b/lldb/source/Host/common/FileSystem.cpp
@@ -9,8 +9,6 @@
 #include "lldb/Host/FileSystem.h"
 
 #include "lldb/Utility/DataBufferLLVM.h"
-#include "lldb/Utility/LLDBAssert.h"
-#include "lldb/Utility/TildeExpressionResolver.h"
 
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Errno.h"
@@ -46,16 +44,6 @@ using namespace llvm;
 
 FileSystem &FileSystem::Instance() { return *InstanceImpl(); }
 
-void FileSystem::Initialize() {
-  lldbassert(!InstanceImpl() && "Already initialized.");
-  InstanceImpl().emplace();
-}
-
-void FileSystem::Initialize(IntrusiveRefCntPtr<vfs::FileSystem> fs) {
-  lldbassert(!InstanceImpl() && "Already initialized.");
-  InstanceImpl().emplace(fs);
-}
-
 void FileSystem::Terminate() {
   lldbassert(InstanceImpl() && "Already terminated.");
   InstanceImpl().reset();
@@ -239,9 +227,9 @@ void FileSystem::Resolve(SmallVectorImpl<char> &path) {
 
   // Resolve tilde in path.
   SmallString<128> resolved(path.begin(), path.end());
-  StandardTildeExpressionResolver Resolver;
-  Resolver.ResolveFullPath(llvm::StringRef(path.begin(), path.size()),
-                           resolved);
+  assert(m_tilde_resolver && "must initialize tilde resolver in constructor");
+  m_tilde_resolver->ResolveFullPath(llvm::StringRef(path.begin(), path.size()),
+                                    resolved);
 
   // Try making the path absolute if it exists.
   SmallString<128> absolute(resolved.begin(), resolved.end());