Remove some std stream usage from Support and TableGen

LLVM's coding standards recommend raw_ostream and MemoryBuffer for
reading and writing text.

This has the side effect of allowing clang to compile more of Support
and TableGen in the Microsoft C++ ABI.

llvm-svn: 187826

1 files changed, 13 insertions, 9 deletions

diff --git a/llvm/lib/Support/LockFileManager.cpp b/llvm/lib/Support/LockFileManager.cpp
index 21c4d4070d2..b1ff22c2e68 100644
--- a/llvm/lib/Support/LockFileManager.cpp
+++ b/llvm/lib/Support/LockFileManager.cpp
@@ -7,9 +7,11 @@
 //
 //===----------------------------------------------------------------------===//
 #include "llvm/Support/LockFileManager.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
-#include <fstream>
 #include <sys/stat.h>
 #include <sys/types.h>
 #if LLVM_ON_WIN32
@@ -35,16 +37,18 @@ LockFileManager::readLockFile(StringRef LockFileName) {
 
   // Read the owning host and PID out of the lock file. If it appears that the
   // owning process is dead, the lock file is invalid.
-  int PID = 0;
-  std::string Hostname;
-  std::ifstream Input(LockFileName.str().c_str());
-  if (Input >> Hostname >> PID && PID > 0 &&
-      processStillExecuting(Hostname, PID))
-    return std::make_pair(Hostname, PID);
+  OwningPtr<MemoryBuffer> MB;
+  if (MemoryBuffer::getFile(LockFileName, MB)) {
+    StringRef Hostname;
+    StringRef PIDStr;
+    tie(Hostname, PIDStr) = getToken(MB->getBuffer(), " ");
+    int PID;
+    if (PIDStr.getAsInteger(10, PID))
+      return std::make_pair(std::string(Hostname), PID);
+  }
 
   // Delete the lock file. It's invalid anyway.
-  bool Existed;
-  sys::fs::remove(LockFileName, Existed);
+  sys::fs::remove(LockFileName);
   return None;
 }