[fpc-pascal] Debug information

Mark Morgan Lloyd markMLl.fpc-pascal at telemetry.co.uk
Tue Sep 11 18:14:57 CEST 2012

Martin wrote:
> On 11/09/2012 10:28, Rainer Stratmann wrote:
>> I found out that there is no line information shown (-gl) if an error 
>> occurs
>> (more or less shortly) after the program loads a dynamic library.
>> This same behaviour happens with fpc version 2.4.2-0 and 2.6.0.
>> If no library is loaded line information is shown.
>> The error adresses are the same in both cases.

How is the library being loaded: using FPC's dynlibs unit?

If using dynlibs, is the problem immediately after loading the library 
(.so) or is it on a call of an entry point in the library?

> This is about debug info written by "DumpStack" or similar (written by 
> the exe itself, to the console)?
> Or debug info shown by gdb using "bt"?
> If the first, does the latter work?
> As from your other replies, the exception occurs in your pascal code. 
> But is this code in a callback from the DLL? (This would mean that 
> stackframes of the DLL exist, and they have no line info)
> Or could for any other reason (including compiled with optimization) 
> there be a stackframe (just one) that has no line info?

Is the DLL successfully called, does it exit predictably, and does the 
stack recover to the state it was on entry (i.e. without an extra or 
missing word)?

Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]

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