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Re: [PATCH] DOT a function directly from a gdb session
On Wed, 12 Dec 2012, Marek Polacek wrote:
> On Wed, Dec 12, 2012 at 01:53:53PM +0100, Richard Biener wrote:
> >
> > This adds the function print_graph_cfg that you can call from a
> > gdb session and directly pipes a dot representation of the
> > function to 'dot -Tx11'. The only change needed to the now very
> > good dumping code is splitting out the actual worker without
> > the FILE handling.
>
> Thanks, I like it. Just a little correction: from gdb session we want
> probably call debug_dot_cfg (cfun).
> Also, usually I get an ICE, e.g.:
> (gdb) b cleanup_cfg
> Breakpoint 1 at 0xe7f260: file /home/marek/src/gcc/gcc/cfgcleanup.c, line 2946.
> (gdb) r
> Starting program: /home/marek/rh/x/trunk/gcc/cc1plus -O2 -ftracer -fno-tree-dce -fno-tree-sra x.c -quiet
>
> Breakpoint 1, cleanup_cfg (mode=16) at /home/marek/src/gcc/gcc/cfgcleanup.c:2946
> 2946 {
> (gdb) call debug_dot_cfg(cfun)
> Detaching after fork from child process 2458.
> x.c: In function ?int main()?:
> x.c:9:1: internal compiler error: in pre_and_rev_post_order_compute, at cfganal.c:869
> }
> ^
> 0x78fb4c pre_and_rev_post_order_compute(int*, int*, bool)
> /home/marek/src/gcc/gcc/cfganal.c:869
> 0xebceb2 print_graph_cfg_1
> /home/marek/src/gcc/gcc/graph.c:186
> 0xebd2a1 debug_dot_cfg(function*)
> /home/marek/src/gcc/gcc/graph.c:259
>
> When I can call debug_dot_cfg and when not?
Well, it now uses dominators - so steven, I suppose "fancy" dumping
should be disabled whenever they are not already computed?
Richard.
k