rework the stat cache, pulling it out of FileManager.h into
its own header and giving it some more structure. No
functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@120030 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/FileSystemStatCache.cpp b/lib/Basic/FileSystemStatCache.cpp
new file mode 100644
index 0000000..8fd31d5
--- /dev/null
+++ b/lib/Basic/FileSystemStatCache.cpp
@@ -0,0 +1,40 @@
+//===--- FileSystemStatCache.cpp - Caching for 'stat' calls ---------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the FileSystemStatCache interface.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/FileSystemStatCache.h"
+#include "llvm/System/Path.h"
+using namespace clang;
+
+MemorizeStatCalls::LookupResult
+MemorizeStatCalls::getStat(const char *Path, struct stat &StatBuf) {
+ LookupResult Result = statChained(Path, StatBuf);
+
+ // If the chained cache didn't know anything about the file, do the stat now
+ // so we can record the result.
+ if (Result == CacheMiss)
+ Result = ::stat(Path, &StatBuf) ? CacheHitMissing : CacheHitExists;
+
+
+ // Do not cache failed stats, it is easy to construct common inconsistent
+ // situations if we do, and they are not important for PCH performance (which
+ // currently only needs the stats to construct the initial FileManager
+ // entries).
+ if (Result == CacheHitMissing)
+ return Result;
+
+ // Cache file 'stat' results and directories with absolutely paths.
+ if (!S_ISDIR(StatBuf.st_mode) || llvm::sys::Path(Path).isAbsolute())
+ StatCalls[Path] = StatResult(Result, StatBuf);
+
+ return Result;
+}