1 files changed, 70 insertions, 0 deletions
diff --git a/llvm/lib/System/Unix/Memory.inc b/llvm/lib/System/Unix/Memory.inc
new file mode 100644
index 00000000000..370b318955e
--- /dev/null
+++ b/llvm/lib/System/Unix/Memory.inc
@@ -0,0 +1,70 @@
+//===- Unix/Memory.cpp - Generic UNIX System Configuration ------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file defines some functions for various memory management utilities.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+#include "llvm/System/Process.h"
+
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+
+namespace llvm {
+
+/// AllocateRWXMemory - Allocate a slab of memory with read/write/execute
+/// permissions.  This is typically used for JIT applications where we want
+/// to emit code to the memory then jump to it.  Getting this type of memory
+/// is very OS specific.
+///
+MemoryBlock Memory::AllocateRWX(unsigned NumBytes) {
+  if (NumBytes == 0) return MemoryBlock();
+
+  long pageSize = Process::GetPageSize();
+  unsigned NumPages = (NumBytes+pageSize-1)/pageSize;
+
+  int fd = -1;
+#ifdef NEED_DEV_ZERO_FOR_MMAP
+  static int zero_fd = open("/dev/zero", O_RDWR);
+  if (zero_fd == -1) {
+    ThrowErrno("Can't open /dev/zero device");
+  }
+  fd = zero_fd;
+#endif
+
+  int flags = MAP_PRIVATE |
+#ifdef HAVE_MMAP_ANONYMOUS
+  MAP_ANONYMOUS
+#else
+  MAP_ANON
+#endif
+  ;
+  void *pa = ::mmap(0, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
+                    flags, fd, 0);
+  if (pa == MAP_FAILED) {
+    ThrowErrno("Can't allocate RWX Memory");
+  }
+  MemoryBlock result;
+  result.Address = pa;
+  result.Size = NumPages*pageSize;
+  return result;
+}
+
+void Memory::ReleaseRWX(MemoryBlock& M) {
+  if (M.Address == 0 || M.Size == 0) return;
+  if (0 != ::munmap(M.Address, M.Size)) {
+    ThrowErrno("Can't release RWX Memory");
+  }
+}
+
+}
+
+// vim: sw=2 smartindent smarttab tw=80 autoindent expandtab