1 files changed, 94 insertions, 0 deletions
diff --git a/gdbsupport/scoped_mmap.h b/gdbsupport/scoped_mmap.h
new file mode 100644
index 00000000000..bab988f364c
--- /dev/null
+++ b/gdbsupport/scoped_mmap.h
@@ -0,0 +1,94 @@
+/* scoped_mmap, automatically unmap files
+
+   Copyright (C) 2018-2020 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef COMMON_SCOPED_MMAP_H
+#define COMMON_SCOPED_MMAP_H
+
+#ifdef HAVE_SYS_MMAN_H
+
+#include <sys/mman.h>
+
+/* A smart-pointer-like class to mmap() and automatically munmap() a memory
+   mapping.  */
+
+class scoped_mmap
+{
+public:
+  scoped_mmap () noexcept : m_mem (MAP_FAILED), m_length (0) {}
+  scoped_mmap (void *addr, size_t length, int prot, int flags, int fd,
+	       off_t offset) noexcept : m_length (length)
+  {
+    m_mem = mmap (addr, m_length, prot, flags, fd, offset);
+  }
+
+  ~scoped_mmap ()
+  {
+    destroy ();
+  }
+
+  scoped_mmap (scoped_mmap &&rhs)
+  {
+    destroy ();
+
+    m_mem = rhs.m_mem;
+    m_length = rhs.m_length;
+
+    rhs.m_mem = MAP_FAILED;
+    rhs.m_length = 0;
+  }
+
+  DISABLE_COPY_AND_ASSIGN (scoped_mmap);
+
+  ATTRIBUTE_UNUSED_RESULT void *release () noexcept
+  {
+    void *mem = m_mem;
+    m_mem = MAP_FAILED;
+    m_length = 0;
+    return mem;
+  }
+
+  void reset (void *addr, size_t length, int prot, int flags, int fd,
+	      off_t offset) noexcept
+  {
+    destroy ();
+
+    m_length = length;
+    m_mem = mmap (addr, m_length, prot, flags, fd, offset);
+  }
+
+  size_t size () const noexcept { return m_length; }
+  void *get () const noexcept { return m_mem; }
+
+private:
+  void destroy ()
+  {
+    if (m_mem != MAP_FAILED)
+      munmap (m_mem, m_length);
+  }
+
+  void *m_mem;
+  size_t m_length;
+};
+
+/* Map FILENAME in memory.  Throw an error if anything goes wrong.  */
+scoped_mmap mmap_file (const char *filename);
+
+#endif /* HAVE_SYS_MMAN_H */
+
+#endif /* COMMON_SCOPED_MMAP_H */