diff options
Diffstat (limited to 'lib/Support/SystemUtils.cpp')
| -rw-r--r-- | lib/Support/SystemUtils.cpp | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/lib/Support/SystemUtils.cpp b/lib/Support/SystemUtils.cpp index 398096a..2400445 100644 --- a/lib/Support/SystemUtils.cpp +++ b/lib/Support/SystemUtils.cpp @@ -12,13 +12,14 @@ // //===----------------------------------------------------------------------===// +#define _POSIX_MAPPED_FILES #include "Support/SystemUtils.h" #include "Config/sys/types.h" #include "Config/sys/stat.h" #include "Config/fcntl.h" #include "Config/sys/wait.h" +#include "Config/sys/mman.h" #include "Config/unistd.h" -#include "Config/config.h" #include <algorithm> #include <fstream> #include <iostream> @@ -268,3 +269,54 @@ int llvm::ExecWait(const char * const old_argv[], // Otherwise, return failure. return 1; } + +/// 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. +/// +void *llvm::AllocateRWXMemory(unsigned NumBytes) { + if (NumBytes == 0) return 0; + static const long pageSize = sysconf(_SC_PAGESIZE); + unsigned NumPages = (NumBytes+pageSize-1)/pageSize; + +/* FIXME: This should use the proper autoconf flags */ +#if defined(i386) || defined(__i386__) || defined(__x86__) + /* Linux and *BSD tend to have these flags named differently. */ +#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS) +# define MAP_ANONYMOUS MAP_ANON +#endif /* defined(MAP_ANON) && !defined(MAP_ANONYMOUS) */ +#elif defined(sparc) || defined(__sparc__) || defined(__sparcv9) +/* nothing */ +#else + std::cerr << "This architecture is not supported by the JIT!\n"; + abort(); + return 0; +#endif + +#ifdef HAVE_MMAP + int fd = -1; +#if defined(__linux__) + fd = 0; +#endif + + unsigned mmapFlags = MAP_PRIVATE|MAP_ANONYMOUS; +#ifdef MAP_NORESERVE + mmapFlags |= MAP_NORESERVE; +#endif + + void *pa = mmap(0, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC, + mmapFlags, fd, 0); + if (pa == MAP_FAILED) { + perror("mmap"); + abort(); + } + return pa; +#else + std::cerr << "Do not know how to allocate mem for the JIT without mmap!\n"; + abort(); + return 0; +#endif +} + + |