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libunwind-eh_elf/README
hp.com!davidm 75b6719352 Update to reflect currently reality.
(Logical change 1.275)
2004-10-15 13:37:27 +00:00

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-*- mode: Outline -*-
This is version 0.97 of the unwind library. At the moment, only the
IA-64 Linux (IPF Linux) platform is fully supported. Some basic
support for x86 and HP-UX/IPF exists also. However, the x86 support
is based mostly on the frame-chain and does not reliably use unwind
information yet, so its utility is limited. Similarly, the HP-UX/IPF
support is incomplete, though it is sufficient to do a basic
backtrace. unw_resume() is not supported, however.
* Important GCC v3.4.[012] Caveat
GCC v3.4.[012] break C++ ABI compatibility and because of that,
libunwind cannot easily be used as the unwinder. The GCC developers
are aware of the problem [1] and the the problem has been fixed for
GCC v3.4.3.
[1] http://gcc.gnu.org/ml/gcc/2004-04/msg00989.html
* General Build Instructions
In general, this library can be built and installed with the following
commands:
$ ./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 \
LDFLAGS="-L$PWD/src/.libs"
** Version 7
To build libunwind with the Intel Electron compiler (ECC), it is
recommended to run configure like this:
$ ./configure CC=ecc CXX=ecc CCAS=gcc CCASFLAGS=-g \
LDFLAGS="-L$PWD/src/.libs"
The reason for this is that ECC uses the Intel assembler, which
doesn't grok some of the IA-64 assembly code in the "tests" directory.
For an ECC-built version of libunwind to work properly, you also need
to ensure that /usr/include/asm/fpu.h contains a "long double" member
called "__dummy" in the declaration of "struct ia64_fpreg". Without
that member, variables of type unw_context_t won't be aligned
properly.
* 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
"configure":
$ 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
workaround.
* 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
fine.
** Expected results on x86 Linux
The following tests are expected to fail on x86 Linux:
test-proc-info (x86 unwinder doesn't use unwind-info yet)
Gtest-exc (unw_resume() not implmented yet)
Ltest-exc (unw_resume() not implmented yet)
test-setjmp (unw_resume() not implmented 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:
tests/bt
tests/Gperf-simple
tests/test-proc-info
tests/test-static-link
tests/Gtest-init
tests/Ltest-init
tests/Gtest-resume-sig
tests/Ltest-resume-sig
* 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
commands:
$ cd tests
$ make perf
* Contacting the Developers
Please direct all questions regarding this library to:
libunwind@linux.hpl.hp.com
For spam protection, you'll have to subscribe to this list before
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subscribe libunwind
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