Re: [ptxdist] Should GDB select XZ?

[Michael Olbrich <m.olbrich@pengutronix.de>]

On Tue, May 07, 2024 at 02:39:01PM +0100, Ian Abbott wrote:
> The configure script of GDB (version 7.6 or later) has a --with-lzma option

That's definitely old enough, so we can rely on the option to be available.
gdb is always a bit tricky because we need to support multiple versions.

> that controls whether GDB will use liblzma or not.  (It is needed to for
> reading .gnu_debuginfo sections from ELF files, if they are present.)  By
> default (if not explicitly enabled or disabled), it will use liblzma if it
> is detected at build time.
> 
> Currently, PTXdist does not configure GDB with any --with-lzma value, so
> whether or not it is configured to use liblzma depends on whether some
> version of XZ has previously been built or not.
> 
> If GDB gets automatically configured to use liblzma, but the XZ package is
> not to be installed (perhaps there is a previous build of XZ in the
> platform's sysroot-target), then there will be a run-time error when running
> GDB due to the missing library.  It also means that the build of GDB may not
> be reproducible.
> 
> It seems to me that PTXdist should have a configuration option to choose
> whether GDB should be built with liblzma support or not (and possibly a
> configuration option to select whether the GDB version is 7.6 or later,
> defaulting to true). The default could depend on
> PTXCONF_TARGET_MINI_DEBUGINFO.  If binaries have a .gnu_debuginfo section
> then we probably want GDB to be able to use it!

Right, gdb should definitely be able to read .gnu_debuginfo sections. I
just never noticed this because I always use gdbserver.

As you probably noticed by now, depending on PTXCONF_TARGET_MINI_DEBUGINFO
does not work because it is defined in the platformconfig and gdb is not.

> I'll attempt to knock up a patch for it.

I appreciate it. The gdb package has seen little updated in the past
because I don't actually use it myself. So fixes from someone who actually
uses it are welcome.

Michael

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