[NaCl SDK] Map active fds to absolute paths.

native_client_sdk/src/libraries/nacl_io/kernel_object.h

Index: native_client_sdk/src/libraries/nacl_io/kernel_object.h
diff --git a/native_client_sdk/src/libraries/nacl_io/kernel_object.h b/native_client_sdk/src/libraries/nacl_io/kernel_object.h
index 70ffb2f54a13e80900067f0b1845e8348be2f591..dcd29f3af13266b6db2d35e626065350c661e89f 100644
--- a/native_client_sdk/src/libraries/nacl_io/kernel_object.h
+++ b/native_client_sdk/src/libraries/nacl_io/kernel_object.h
@@ -37,6 +37,7 @@ class KernelObject {
     int flags;
   };
   typedef std::vector<Descriptor_t> HandleMap_t;
+  typedef std::map<int, std::string> FdPathMap_t;
   typedef std::map<std::string, ScopedFilesystem> FsMap_t;
 
   KernelObject();
@@ -65,6 +66,8 @@ class KernelObject {
 
   // Get FD-specific flags (currently only FD_CLOEXEC is supported).
   Error GetFDFlags(int fd, int* out_flags);
+  // Get path at which FD was opened, if available.
+  std::string GetFDPath(int fd);
   // Set FD-specific flags (currently only FD_CLOEXEC is supported).
   Error SetFDFlags(int fd, int flags);
 
@@ -75,7 +78,7 @@ class KernelObject {
   // Allocate a new fd and assign the handle to it, while
   // ref counting the handle and associated filesystem.
   // Assumes |handle| is non-NULL;
-  int AllocateFD(const ScopedKernelHandle& handle);
+  int AllocateFD(const ScopedKernelHandle& handle, std::string path);
 
   // Assumes |handle| is non-NULL;
   void FreeAndReassignFD(int fd, const ScopedKernelHandle& handle);
@@ -92,6 +95,7 @@ class KernelObject {
   std::string cwd_;
   std::vector<int> free_fds_;
   HandleMap_t handle_map_;
+  FdPathMap_t fd_paths_;
   FsMap_t filesystems_;
 
   // Lock to protect free_fds_ and handle_map_.