[LLVMdev] Debugging LLVM IR with GDB

Renato Golin rengolin at systemcall.org
Fri Oct 19 07:08:38 PDT 2012

On 18 October 2012 15:35, Will Dietz <willdtz at gmail.com> wrote:
> The pass itself is rather simple--the hard problem it solves is
> emitting the IR to disk and reasoning about what Instruction* is on
> what line, which really shouldn't be a problem if done properly in

Another thing, which would be really great, but also really hard, is
to map the SSA registers to their values.

So, in GDB, you could say:

(gdb) print %117
(int) %117 = 4

Though you'd have to generate all possible locations of the value in
the generated code, which can be a pain in the Dwarf back-end.

But just the line information is already great, as it interlaces with
C source lines, so it's easy to see what C line mapped to what group
of IR lines.

+1 for a patch to implement that! ;)



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