Re: [Sbcl-help] Compiler implementation

[Jim W. <jw...@dr...>]

Peter Keller <ps...@cs...> writes:

> On Thu, Feb 03, 2011 at 12:28:35PM -0500, Michael J. Barillier wrote:
>> I've been curious about how the SBCL compiler works (but not enough to
>> code-dive).  Docs say that SBCL compiles to native code, and
>> disassembling a function shows native instructions, but how does SBCL
>> load that into an executable area of memory?  Intel processors and
>> others don't allow execution of memory segments (as I recall from
>> assembly hacking in a previous life), so how does SBCL generate a stream
>> of machine instructions and call the entry point?
>
> Under unix, the system level calls of mmap() and mprotect() are your
> friends....

... and it's worth noting that ld.so / rtld, the shared library loader,
is itself a user-space program whose source is often available for
comparison.

-- 
				Jim Wise
				jw...@dr...