[Libunwind-devel] arm cross-compile/link errors: undefined reference to AO_fetch_and_add & AO_fetch_and_add1

[Allen Hamedany]

Hi,

Having called libunwind APIs in my code, I am trying to get a clean 
cross-compile/link w/o much success.


Here's pertinent info:
HOST: runs centos6.5 on 32bit machine
TARGET: armv7l on TI AM335x (linux)

The goal is to run the arm executable on the arm TARGET machine.
However, development and debugging are done on HOST machine.
Debugging is done using cross-gdb.

TARGET:
Linux 3.2.0+ #48  armv7l GNU/Linux



HOST:
Linux 2.6.32-431.17.1.el6.i686 #1 SMP i686 i686 i386 GNU/Linux

Cross-tool-chain versions (running on HOST):
gcc/g++ version: arm-arago-linux-gnueabi-gcc/g++ v4.5.3
ld version: GNU ld (GNU Binutils) v2.20.1.20100303

Native HOST  versions:
gcc (GCC)/g++: v4.5.2
ld: GNU ld v2.20.51.0.2-5.36.el6 20100205


+==========================+

libunwind1.1:

env vars:
ti=<arm-toolchain-path>/bin
CFLAGS="-std=gnu99 "


HOST=i686-pc-linux-gnu
TARGET=arm-arago-linux-gnueabi

./configure --host=$HOST --target=$TARGET CC=$ti/*gcc CFLAGS=$CFLAGS 
CXX=$ti/*g++ CXXFLAGS=$CXXFLAGS 
LDFLAGS="-L<unwind-inst-dir>/libunwind/libunwind-1.1/src/.l
ibs"

I made this softlink:<arm-toolchain-path>/usr/lib/libunwind-arm.so to 
<libunwind-extract-area>/libunwind-1.1/src/.libs/libunwind-arm.so

When cross-linking to my app using switches:
-Xlinker -lunwind-arm

I get:

/scratch/ti/AM335x/linux-devkit/bin/../arm-arago-linux-gnueabi/usr/lib/libunwind-arm.so: 
undefined reference to 'AO_fetch_and_add'
/scratch/ti/AM335x/linux-devkit/bin/../arm-arago-linux-gnueabi/usr/lib/libunwind-arm.so: 
undefined reference to 'AO_fetch_and_add1'

+============================+
I tried fixing the above link w/building atomic-ops lib.
Downloaded and installed libatomic_ops-7.4.2.
The following libs are created:
libatomic_ops.a
libatomic_ops_gpl.a

I also softlinked the above atomic-ops libs as 
<arm-toolchain-path>/usr/lib/libatomic_ops.a & lib_atomic_ops_gpl.a

I retried linking my app using the following switches:
-Xlinker -latomic_ops_gpl -latomic_ops -lunwind-arm

However, I still get the above "undefined reference" errors.
Any help is much appreciated.