Re: Getting oriented

[Redwood (Daniel)]

Thanks, Carl. Yes, I’ve read about this. Part of what I’m trying to do is avoid 
going down useless alleys. We’ll see if this helps.

I also suspect Han-Wen’s advice (ly_display_scm()) will help as well…

-d
> On Mar 30, 2016, at 12:10 PM, Carl Sorensen <address@hidden> wrote:
> 
> 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
>