BananaPi M3: "undefined reference to `XRRFreeMonitors'  and
'XRRGetMonitors'
lazarus / 1-Linux

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att2 · 2016-11-16 13:01

Hello,
My hardware: Bananapi m3
Quotepi@bpi-iot-ros-ai:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.1 LTS
Release:        16.04
Codename:       xenial
pi@bpi-iot-ros-ai:~$ uname -a
Linux bpi-iot-ros-ai 3.4.39-BPI-M3-Kernel #1 SMP PREEMPT Tue May 3
13:47:01 UTC 2016 armv7l armv7l armv7l GNU/Linux

I freshly installed Lazarus with
Quoteapt-get install fp-compiler-3.0.0
apt-get install lazarus-1.6

Trying to compile a test program results in:

QuoteCompile Project, Target: project1: Exit code 256, Errors: 1,
Warnings: 2
project1.lpr(22,0) Warning: "crtbegin.o" not found, this will probably
cause a linking failure
project1.lpr(22,0) Warning: "crtend.o" not found, this will probably
cause a linking failure
/usr/bin/ld.bfd: warning: link.res contains output sections; did you
forget -T?
//usr/lib/arm-linux-gnueabihf/libgdk-x11-2.0.so: undefined reference
to `XRRFreeMonitors'
//usr/lib/arm-linux-gnueabihf/libgdk-x11-2.0.so: undefined reference
to `XRRGetMonitors'
project1.lpr(22,0) Error: Error while linking

Yes, about the "crtbegin.o" I know I have to edit the GCC library path
in /etc/fpc.cfg  - I will do that (later).
What really gets me clueless is the
//usr/lib/arm-linux-gnueabihf/libgdk-x11-2.0.so: undefined reference
to `XRRFreeMonitors'
//usr/lib/arm-linux-gnueabihf/libgdk-x11-2.0.so: undefined reference
to `XRRGetMonitors'

I did not fail to miss these double slashes "//" at the beginning.
Some config file or other must be wrong.
Can you help me to fix that, please?

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marcov · 2016-11-16 13:04

Try linking lib "Xrandr". Probably the distribution's libraries have
some problem in their dependencies.

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att2 · 2016-11-16 13:33

which lib XRandr... link to where? Do I have to edit /etc/fpc.cfg or
what do you mean exactly ?

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Leledumbo · 2016-11-16 18:16

Quote from: att2 on November 16, 2016, 02:01:20 pmMy hardware:
Bananapi m3
Better mention your OS, Banana Pi has more than 1 OS available.

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att2 · 2016-11-17 08:13

Quote from: Leledumbo on November 16, 2016, 07:16:53 pmQuote from:
att2 on November 16, 2016, 02:01:20 pmMy hardware: Bananapi m3
Better mention your OS, Banana Pi has more than 1 OS available.
I thought that the "lsb_release" command was obvious? -> Ubuntu Mate
16.04.1 LTS "Xenial", based on the image from :

http://www.banana-pi.org/m3-download.html   ->  "Ubuntu 16.04 Mate
desktop" (first in list on that page)

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marcov · 2016-11-17 09:18

Quote from: att2 on November 16, 2016, 02:33:21 pmwhich lib XRandr...
link to where? Do I have to edit /etc/fpc.cfg or what do you mean
exactly ?

You need to tell the linker which libraries to link using $linklib in
header units or using -k-l<libraryname>.

In theory, a library thus linked would automatically pull in all
dependencies, but this does not always happen in practice.

The xrandr was just from googling the symbolnames to do an educated
guess (and not more than that), to try to put you on the path.