Re: Contributing LLVM.org patches to gud.el

[David Kastrup]

Daniel Colascione <address@hidden> writes:

> On 02/10/2015 07:43 PM, Stephen J. Turnbull wrote:
>> Eli Zaretskii writes:
>> 
>>  > > Uh, there is a connection.  Because modern IDEs tend to have useful
>>  > > program information when debugging instead of (optimized out).
>>  > 
>>  > Compile with -Og (which should be the default anyway), and you have
>>  > that with GCC/GDB as well.
>> 
>> Er, most programs I compile default to -O3 (I mean upstream does).  So
>> you can't debug a production build even if you have symbols.  Arrgh
>
> What exactly are the DWARF deficiencies that prevent a debugger from
> unwinding caller-saved registers to their original values? The
> specification seems more than powerful enough for the task.

The issue mostly are values which are not present explicitly anywhere.
If the compiler can deduce the value/effect of a variable, it does not
need to store it anywhere.

-- 
David Kastrup