Re: Breakpoint commands compiler

[Phil Muldoon <pmuldoon at redhat dot com>]

On 17/10/14 17:57, Doug Evans wrote:
> On Fri, Oct 17, 2014 at 8:42 AM, Daniel Gutson
> <daniel.gutson@tallertechnologies.com> wrote:
>> Hi,
>>
>>     gdb is sometimes used for changing the runtime behavior of a program.
>> That is, suppose there is a program that has a bug,
>> it is spotted with gdb, then I create a set of non-stopping breakpoints that
>> "fix" the runtime behavior by altering memory and registers.
>> It does work, but it's slow.
>>
>> I was thinking to start a project to add a "breakpoint commands compiler"
>> to gdb, which basically generates C code from the breakpoint commands
>> (one function per breakpoint),
>> which in turns calls a C API (similar to the python api), invokes the compiler
>> (user-specified), loads it as a shared object, and finally replaces the commands
>> of the breakpoints by calls to the compiled breakpoint-functions.
>>
>> Any comment/suggestion? Would this be accepted within gdb?
>
> Hi.
>
> For reference sake a patch has been submitted by Red Hat to add a
> "compile" command.
> [The patch is still being reviewed, it hasn't been committed yet.]
> It doesn't compile gdb commands, but allows one to add compiled code
> to the inferior in the debugging session.
>
Just as an an add-on, we've begun detailing the internals of the
compile command here:

https://sourceware.org/gdb/wiki/GCCCompileAndExecute

That page is draft and is not complete yet.  It should be complete
soon.

A minor status update.  I will be checking the GCC patches in next
week (we have permission there).  And then we will be
pursuing/re-pinging the GDB patches right after.

Cheers

Phil