[fpc-devel] RECENT Commit breaking FpDebug - Dwarf / and not even fully fixing the original issue

[Martin Frb]

On 30/04/2026 00:50, Pierre Muller via fpc-devel wrote:
>
>   I tried recently to use dwarfdump, a standard unix utility,
> and this tool does indeed list a few issues with
> the DWARF information generated by Free Pascal.
>
>   I didn't have time to investigate these issues.

I just did try myself.

The list definitely includes false positives.
dwarfdump [Mar  6 2026 19:38:46 (libdwarf 2.3.1 dwarfdump 2.3.1)]
And the latest 3.3.1 fpc


Proof?
*** DWARF CHECK: DW_TAG_compile_unit -> DW_TAG_interface_type: tag-tree 
relation is not standard. ***


1) The dwarf docs don't say anything that wouldn't allow this. And as 
other types are declared in the CU, where else should an intf be?

2) From dwarfdump sources
https://github.com/avast/libdwarf/blob/master/libdwarf/dwarfdump/tag_tree.list

2a)
>  Since DWARF is generally descriptive, not prescriptive,
>     this list is at best a current understanding of
>     appropriate practice.  Moreover the the dwarf standard
>     does not actually list the tag-tag dependencies.
>     So mistakes in the list below is certainly possible.


2b)
DW_TAG_interface_type is not listed as possible child to any of the 
other tags.

It is only listed as a parent specifying which children it can have.
So given the list in the above file, it couldn't be used anywhere at all.

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