| ID: | 869 |
| From: | ge...@igor2.repo.hu |
| Date: | Sun, 10 Sep 2017 08:31:34 +0200 (CEST) |
| Subject: | [pcb-rnd] lesstif HID: should work everywhere, no more BadWindow |
Hi all,
As of r11396, the lesstif HID should work on every system, with both
lesstif and motif.
If you can, please install the lesstif or motif devel package and
reconfigure pcb-rnd so you can test the lesstif HID if needed. It's a good
way to cross-check GUI bugs to decide whether it's gtk-specific or not.
Boring details:
The long standing bug was a rather tricky one to figure. I never
experienced it on my main systems but only one box while other
users/developers consistently reported it. I thought it was a motif
version problem, maybe something changed recently and others use a too new
or too old version compared to my system.
Then I started to work on the attribute dialog upgrade and for some of the
lesstif code I decided to set up a smallish test bench in work/ to try out
ideas without having to compile and run pcb-rnd. And the minimal "hello
world" test program immediately produced the same runtime error. I went on
and copied the official test programs from motif and lesstif, and boom,
the same error!
That's when I started to investigate the build parameters. It turned out
the order of linking must be -lXm _before_ -lXt. If the order is wrong,
there is no link time error, but the misleading runtime error.
And the difference between my systems and everyone else's? Opengl. I don't
have it, so my link list had lesstif libs before gtk libs and within the
lesstif lib link set the order is -lXm -lXt. With opengl, -lXt got on the
list with opengl libs, way before lesstif, that's how we ended up with
"-lXt <a_lot_of_other_stuff> -lXm -lXt", from which the second -lXt got
removed as redundant.
Solutuin: this is a very special case. I've been coding C on various UNIX
systems since about 1999, and never seen a link order causing such runtime
error. Nevertheless, we may later on have other link order problems which
would cause linking error, so I decided to go for a generic/proper
solution. I've added a new feature in scconfig so that two items in a list
can be reordered to meet a specific requirement. It does that by minimal
change to the list, e.g. moving the out-of-order item only, right before
(or after) the target word. Thw two lines that got added to
src/Makefile.in:
# Lesstif requires that -lXm is before -lXt or else there is a runtime BadWindow
order /local/pcb/LDFLAGS {-lXm} {before} {-lXt}
This moves -lXm to right before -lXt if both are present on LDFLAGS and
are in the wrong order.
Regards,
Igor2
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869 [pcb-rnd] lesstif HID: should work everywhere, no more BadWindow from ge...@igor2.repo.hu