Can LLVM jitter emit the native code in continus memory addresses?

Question

I have question relating to LLVM Jitter: Can i obligue the LLVM Jitter to emit the native code in continuous memory addresses ? and to be PIC ? what i want to do is to move save the JIT code in a file and load it for execution later ..

what i mean by "load" is to simply read the bits from file into buffer i don't want to generate elf or something like this.

Here's an example: suppose i have C source file which contain:

Global variables
----------------
Function Foo()
----------------
Function Too()

when i request the JIT code i want the JIT to be in continus memory addresses:

0x100: Global Vars (take 16 Byte)
0x110: Foo() Code (take 32 Byte)
0x130: Too() Code (take 32 Byte)
0x150: end.

Answer 1

To store JIT'ed code in some region of memory you can write special version of JITMemoryManager (include/llvm/ExecutionEngine/JITMemoryManager.h lib/ExecutionEngine/JIT/JITMemoryManager.cpp). There is example of custom JIM MM here: unittests/ExecutionEngine/JIT/JITTest.cpp, it is an RecordingJITMemoryManager which logs main JIT MM calls.

As I can see (as LLVM 2.9), ARM JIT have isPIC set to False and X86 JIT is capable of generating PIC code.

The biggest problem, seems, is loading of precompiled code.