Re: [PATCH 1/2] Report call site for inlined functions

[Pedro Alves <palves at redhat dot com>]

On 10/20/2017 07:46 PM, Keith Seitz wrote:
> [My reply seems not to have made it to sourceware, so I'm resending.]
> 
> On 07/18/2017 12:05 PM, Pedro Alves wrote:
>> On 07/11/2017 03:36 AM, Keith Seitz wrote:
>>>
>>> Here you can see the new call-site-func, call-site-file, call-site-fullname,
>>> and call-site-line.
>>
>> The non-inlined call site seems sufficient info to me, at least for
>> the  CLI.  I'm not sure whether "call-site" is sufficiently clear that
>> it's referring to that vs the immediate potential inlined-too
>> caller though.  I think at least the docs need such a clarification.
> 
> There seems to be consensus on the (lack of) utility of this call-site info, so in the next revision (to follow), I've chosen to remove it all.  I think that pretty much resolves (by deletion!) most of your concerns/comments. I've also removed the inlined_symbol proposal since that is also no longer necessary. 

I think my observations in
<https://sourceware.org/ml/gdb-patches/2017-03/msg00382.html>
still make sense, and I don't know about consensus, but OK, let's
move on.  I'll take a look at the new version.

> 
>>> diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
>>> index 0fdcd42..3b3193b 100644
>>> --- a/gdb/dwarf2read.c
>>> +++ b/gdb/dwarf2read.c
>>> @@ -11540,13 +11571,28 @@ read_func_scope (struct die_info *die, struct dwarf2_cu *cu)
>>>  	{
>>>  	  templ_func = allocate_template_symbol (objfile);
>>>  	  templ_func->base.is_cplus_template_function = 1;
>>> +	  symbol_storage = (struct symbol *) templ_func;
>>>  	  break;
>>>  	}
>>>      }
>>>  
>>> +  /* If we have an inlined symbol, we must also allocate a different
>>> +     symbol.  */
>>
>> How does this work when you have an (inlined) template function?
>> Like e.g.,:
>>
>> template<typename T>
>> static T inline_func (T val)
>> {
>>   return val * 2;
>> }
>>
>> int
>> not_inline_func (int val)
>> {
>>   return inline_func (val * 2);
>> }
>>
> 
> I realize this was asked in relation to the proposed (and now deleted) inline_symbol, but to be clear, the above example works:
> 
> (gdb) b inline_func<int>
> Breakpoint 1 at 0x4004c0: file inline-t.cc, line 9.
> (gdb) i b
> Num     Type           Disp Enb Address            What
> 1       breakpoint     keep y   0x00000000004004c0 in inline_func<int> 
>                                                    at inline-t.cc:9

OK, it seems like a DIE can't be both DW_TAG_inlined_subroutine
and a template (kind of makes sense), so you couldn't ever end up
calling both allocate_template_symbol and allocate_inlined_symbol
for the same symbol (which is what I was worrying about, because
the code didn't consider/guard against that).

Thanks,
Pedro Alves