Re: [Qemu-devel] [PATCH 4/8] convert libqemuutil to meson

[Paolo Bonzini]

On 27/07/19 09:16, Markus Armbruster wrote:
> We started with a single trace-events.  That wasn't good, so we split it
> up into one per directory.  That isn't good, so what about splitting it
> up into one per source file?  Pass -DTRACE_HEADER='"trace-DIR-FOO.h"
> instead of -DTRACE_HEADER='"trace-DIR.h"' when compiling DIR/FOO.c.

For Make this would all work great, however not for Meson because it
doesn't allow per-file compile flags.

Meson maintainers suggest building a static library for each special set
of compile flags; we could do that automatically per-directory(*) but it
would be harder to scale that to per-file.

(*) Still, I'd rather go on with the forwarding headers and look into
that later, to ease review.

Paolo

> This is admittedly a half-baked idea.  It doesn't address tracepoints in
> headers, yet.  But those headers are rare.  A quick grep finds some
> twenty possibles.  Perhaps we can tolerate manual #include there.
> 
> Since we're discussing half-baked ideas already, let me throw out
> another one: move the tracepoint declarations from trace-events into the
> source files.  No more silly merge conflicts between patches related
> only through a shared trace-events file.
> 
> One more: make the format string optional, default to one containing the
> declared parameter names and the obvious conversion specifications.
> Because format strings like this one
> 
>     visit_start_struct(void *v, const char *name, void *obj, size_t size) 
> "v=%p name=%s obj=%p size=%zu"
> 
> add zero bits of information to the declaration preceding it :)
> 
> [...]
>