blob: 511fb0cd0229b26ed47281884d3fc9464c0cb493 [file] [log] [blame]
-*- mode: Outline -*-
This is version 1.0 of the unwind library. This library supports
several architecture/operating-system combinations:
Linux/x86-64: Works well.
Linux/x86: Works well.
Linux/ARM: Works well.
Linux/IA-64: Fully tested and supported.
Linux/PARISC: Works well, but C library missing unwind-info.
HP-UX/IA-64: Mostly works but known to have some serious limitations.
Linux/AArch64: Newly added.
Linux/PPC64: Newly added.
Linux/SuperH: Newly added.
FreeBSD/i386: Newly added.
FreeBSD/x86-64: Newly added (FreeBSD architecture is known as amd64).
* General Build Instructions
In general, this library can be built and installed with the following
$ autoreconf -i # Needed only for building from git. Depends on libtool.
$ ./configure
$ make
$ make install prefix=PREFIX
where PREFIX is the installation prefix. By default, a prefix of
/usr/local is used, such that libunwind.a is installed in
/usr/local/lib and unwind.h is installed in /usr/local/include. For
testing, you may want to use a prefix of /usr/local instead.
* Building with Intel compiler
** Version 8 and later
Starting with version 8, the preferred name for the IA-64 Intel
compiler is "icc" (same name as on x86). Thus, the configure-line
should look like this:
$ ./configure CC=icc CFLAGS="-g -O3 -ip" CXX=icc CCAS=gcc CCASFLAGS=-g \
* Building on HP-UX
For the time being, libunwind must be built with GCC on HP-UX.
libunwind should be configured and installed on HP-UX like this:
$ ./configure CFLAGS="-g -O2 -mlp64" CXXFLAGS="-g -O2 -mlp64"
Caveat: Unwinding of 32-bit (ILP32) binaries is not supported
at the moment.
** Workaround for older versions of GCC
GCC v3.0 and GCC v3.2 ship with a bad version of sys/types.h. The
workaround is to issue the following commands before running
$ mkdir $top_dir/include/sys
$ cp /usr/include/sys/types.h $top_dir/include/sys
GCC v3.3.2 or later have been fixed and do not require this
* Building for PowerPC64 / Linux
For building for power64 you should use:
$ ./configure CFLAGS="-g -O2 -m64" CXXFLAGS="-g -O2 -m64"
If your power support altivec registers:
$ ./configure CFLAGS="-g -O2 -m64 -maltivec" CXXFLAGS="-g -O2 -m64 -maltivec"
To check if your processor has support for vector registers (altivec):
cat /proc/cpuinfo | grep altivec
and should have something like this:
cpu : PPC970, altivec supported
If libunwind seems to not work (backtracing failing), try to compile
it with -O0, without optimizations. There are some compiler problems
depending on the version of your gcc.
* Building on FreeBSD
General building instructions apply. To build and execute several tests,
you need libexecinfo library available in ports as devel/libexecinfo.
Development of the port was done of FreeBSD 8.0-STABLE. The library
was build with the system compiler that is modified version of gcc 4.2.1,
as well as the gcc 4.4.3.
* Regression Testing
After building the library, you can run a set of regression tests with:
$ make check
** Expected results on IA-64 Linux
Unless you have a very recent C library and compiler installed, it is
currently expected to have the following tests fail on IA-64 Linux:
Gtest-init (should pass starting with glibc-2.3.x/gcc-3.4)
Ltest-init (should pass starting with glibc-2.3.x/gcc-3.4)
test-ptrace (should pass starting with glibc-2.3.x/gcc-3.4)
run-ia64-test-dyn1 (should pass starting with glibc-2.3.x)
This does not mean that libunwind cannot be used with older compilers
or C libraries, it just means that for certain corner cases, unwinding
will fail. Since they're corner cases, it is not likely for
applications to trigger them.
Note: If you get lots of errors in Gia64-test-nat and Lia64-test-nat, it's
almost certainly a sign of an old assembler. The GNU assembler used
to encode previous-stack-pointer-relative offsets incorrectly.
This bug was fixed on 21-Sep-2004 so any later assembler will be
** Expected results on x86 Linux
The following tests are expected to fail on x86 Linux:
Gtest-resume-sig (fails to get SIGUSR2)
Ltest-resume-sig (likewise)
Gtest-dyn1 (no dynamic unwind info support yet)
Ltest-dyn1 (no dynamic unwind info support yet)
test-setjmp (longjmp() not implemented yet)
run-check-namespace (no _Ux86_getcontext yet)
** Expected results on x86-64 Linux
The following tests are expected to fail on x86-64 Linux:
Gtest-dyn1 (no dynamic unwind info support yet)
Ltest-dyn1 (no dynamic unwind info support yet)
Gtest-init (see
Ltest-init (likewise)
test-async-sig (crashes due to bad unwind-info?)
test-setjmp (longjmp() not implemented yet)
run-check-namespace (no _Ux86_64_getcontext yet)
run-ptrace-mapper (??? investigate)
run-ptrace-misc (see
** Expected results on PARISC Linux
Caveat: GCC v3.4 or newer is needed on PA-RISC Linux. Earlier
versions of the compiler failed to generate the exception-handling
program header (GNU_EH_FRAME) needed for unwinding.
The following tests are expected to fail on x86-64 Linux:
Gtest-bt (backtrace truncated at kill() due to lack of unwind-info)
Ltest-bt (likewise)
Gtest-resume-sig (Gresume.c:my_rt_sigreturn() is wrong somehow)
Ltest-resume-sig (likewise)
Gtest-init (likewise)
Ltest-init (likewise)
Gtest-dyn1 (no dynamic unwind info support yet)
Ltest-dyn1 (no dynamic unwind info support yet)
test-setjmp (longjmp() not implemented yet)
run-check-namespace (toolchain doesn't support HIDDEN yet)
** Expected results on HP-UX
"make check" is currently unsupported for HP-UX. You can try to run
it, but most tests will fail (and some may fail to terminate). The
only test programs that are known to work at this time are:
** Expected results on PPC64 Linux
"make check" should run with no more than 10 out of 24 tests failed.
* Performance Testing
This distribution includes a few simple performance tests which give
some idea of the basic cost of various libunwind operations. After
building the library, you can run these tests with the following
$ cd tests
$ make perf
* Contacting the Developers
Please direct all questions regarding this library to:
You can do this by sending a mail to with
a body of:
subscribe libunwind-devel
or you can subscribe and manage your subscription via the
web-interface at: