Re: [patch] Add debug_frame parsing

[Andrew Cagney <cagney@redhat.com>]

Mark Wielaard wrote:
> Hi,
>
> This patch widens out libunwind interface to accept either eh_frame or
> debug_frame tables and adds support for parsing debug_frame data. It
> currently does a linear search through the data to find the right fde
> and corresponding cie by making the right adjustments. Although it does
> find the right fde covering the ip ranges, it doesn't always run the cfi
> program correctly. So for now the default is still the default and
> debug_frame is only used as fallback when eh_frame data cannot be found
> (that can be changed in a simple if statement, see the FIXME in UnwindH
> - that will however give a couple of test failures). It also fixes a
> couple of libunwind issues found when working on this (direct usage of
> local memory space, error values not being negative and unw_word being
> 64bit != dwarf 64 format is always in use).
>
>   
Nice work mark; this gets us to a much more reliable unwinder!

Andrew

> frysk-imports/libunwind/ChangeLog
> 2008-01-17  Mark Wielaard  <mwielaard@redhat.com>
>
>     * include/dwarf.h (dwarf_extract_proc_info_from_fde): Pass
>     table_start.
>     * src/dwarf/Gfde.c (is_cie_id): Removed.
>     (parse_cie): Accept debug and eh cie ids.
>     (dwarf_extract_proc_info_from_fde): Accept table_start. Calculate
>     correct cie_addr. Fix error reporting.
>     * src/dwarf/Gfind_proc_info-lsb.c (linear_search): Don't depend
>     on local address space. Pass table start for fde parsing.
>     (dwarf_search_unwind_table): Handle debug_frame by linear search.
>     * src/mi/Gget_unwind_table.c (get_frame_table, get_debug_table):
>     new functions.
>     (unw_get_unwind_table): Call either get_frame_table or
>     get_debug_table depending on format.
>
> frysk-sys/lib/unwind/ChangeLog
> 2008-01-17  Mark Wielaard  <mwielaard@redhat.com>
>
>     * cni/UnwindH.hxx (get_eh_frame_hdr_addr): Find and return
>     debug_frame address and set pi->format.
>     (createProcInfoFromElfImage): Handle either debug_frame or
>     eh_frame addresses.
>
> Tested on x86_64 and x86 (fedora and centos, which both have full
> eh_frame coverage, so admittedly most of the new code paths aren't hit
> yet).
>
> Cheers,
>
> Mark
>