This patch adds support for the powerpc64le-linux platform. It consists
of two main features:
- Support little-endian byte order
This is done via a "big_endian" member of struct unw_addr_space,
which is evaluated by common code via the dwarf_is_big_endian
macro, and also in endian-aware code in unw_is_signal_frame.
- Support the ELFv2 ABI
This is done via an "abi" member of struct unw_addr_space. This
is currently only needed in tdep_get_func_addr, since the ELFv2
ABI does not use function descriptors.
Both new members are initialized in unw_create_addr_space and
ppc64_local_addr_space_init, following the mips precedent.
Since ppc32 and ppc64 now no longer share the unw_create_addr_space
implementation, the file is duplicated from the ppc directory into
ppc32/ppc64.
Tested on powerpc64-linux and powerpc64le-linux. Support on LE
seems to be as good as existing BE support; I have not attempted to
fix the existing shortcomings of PPC support that already cause a
number to tests to fail due to unimplemented features.
Signed-off-by: Ulrich Weigand <uweigand@de.ibm.com>
Dropping the extra frame for unw_backtrace itself using unw_step is
approximately 15% slower than skipping the frame in tdep_trace. So
drop the frame in the latter, and make the function a private
implementation detail for libunwind, not an exported interface.
Also moves unw_getcontext call back into unw_backtrace to avoid an
extra call frame in case slow_backtrace does not get inlined into
unw_backtrace.
Adds new function to perform a pure stack walk without unwinding,
functionally similar to backtrace() but accelerated by an address
attribute cache the caller maintains across calls.
