Re: Getting oriented

[Carl Sorensen]

On 3/30/16 10:12 AM, "address@hidden on
behalf of Redwood (Daniel)"
<address@hidden on behalf of
address@hidden> wrote:

>
>2)  I try debugging from within C++
>
>(gdb) b Performance::output
>Breakpoint 1 at 0x82d6750: file performance.cc, line 72.
>(gdb) r dant.ly
>[Š]
>Breakpoint 1, Performance::output (this=0x87a74f0, midi_stream=...,
>    performance_name="") at performance.cc:72
>(gdb) p *this
>$1 = {<Music_output> = {<Smob<Music_output>> = {<Smob_core> = {
>        self_scm_ = 0xb2915d30}, <Smob_base<Music_output>> = {
>        static smob_tag_ = 14975, static scm_init_ = {static list_ =
>    0x84c3edc <Smob_base<Scale>::scm_init_>, fun_ = 0x80e12b0
>     <Smob_base<Music_output>::init()>,
>          next_ = 0x84bd090 <Smob_base<Paper_outputter>::scm_init_>},
>        static smob_name_ = "Music_output"}, protection_cons_ = 0x404},
>    _vptr.Music_output = 0x83cc308 <vtable for Performance+8>,
>    static type_p_name_ = "ly:music-output?"},
>  audio_staffs_ = std::vector of length 2, capacity 2 = {0x87a6a18,
>    0x87a6c88}, audio_elements_ = std::vector of length 18, capacity 32 =
>{
>    0x87a6a18, 0x865a798, 0x865a7b0, 0x865a900, 0x865c3b0, 0x865c4b0,
>    0x865c4f0, 0x865a8e8, 0x87a4838, 0x87a6cf8, 0x87a6c88, 0x865caf0,
>    0x865cd38, 0x865c910, 0x865c700, 0x865c788, 0x865ce30, 0x865c660},
>midi_ = 
>    0x87a4ff0, ports_ = false, header_ = 0x404}
>
>My guess is that most of these raw numbers are actually scheme objects,
>which I don¹t know how to debug.

Please look at section 10.7.2 of the Contributor's Guide.  It has a
gdbinit file that should allow you to do something like

ps audio_elements_[0]

or 

pmusic *this

at a debugger prompt to see the scheme object.

Warning -- I haven't tried this.  And I'm just shooting in the dark.  But
the gdbinit file certainly helped me in the past.

HTH,

Carl