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For PR351: 

* Ensure #includes are wrapped with appropriate HAVE_ guards
* Consolidate implementation from operating system specific directory.

llvm-svn: 19157
This commit is contained in:
Reid Spencer 2004-12-27 06:17:03 +00:00
parent d554bbcefd
commit 47cd653411
1 changed files with 50 additions and 0 deletions
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50
llvm/lib/System/Unix/Memory.cpp
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@ -12,9 +12,59 @@
//===----------------------------------------------------------------------===//
#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