-- Initial message by Tom Tromey:
While testing on AIX, I happened to notice an internal error coming
from parse_probes. This happens because there are no probes defined
on this platform. This patch fixes the problem by changing an assert
into an ordinary error, and then changing the relevant caller to cope.
This fixes a few tests on AIX; also regtested on x86-64 Fedora 18.
-- Followup by Sergio Durigan Junior:
By reading the patch (and the original code), I found it a little bit
obscure, so I took the liberty to try to improve it. Here's the patch.
Could you please take a look and see if it works on AIX (and also if you
like the approach)?
gdb/
2014-03-20 Tom Tromey <tromey@redhat.com>
Sergio Durigan Junior <sergiodj@redhat.com>
* probe.c (parse_probes): Turn assert into an ordinary error.
* break-catch-throw.c (re_set_exception_catchpoint): Ignore
exceptions when parsing probes. Rearrange the code for clarity.
This changes the probes to be independent of the program space.
After this, when a probe's address is needed, it is determined by
applying offsets at the point of use.
This introduces a bound_probe object, similar to bound minimal
symbols. Objects of this type are used when it's necessary to pass a
probe and its corresponding objfile.
This removes the backlink from probe to objfile, which was primarily
used to fetch the architecture to use.
This adds a get_probe_address function which calls a probe method to
compute the probe's relocated address. Similarly, it adds an objfile
parameter to the semaphore methods so they can do the relocation
properly as well.
2014-03-03 Tom Tromey <tromey@redhat.com>
* break-catch-throw.c (fetch_probe_arguments): Use bound probes.
* breakpoint.c (create_longjmp_master_breakpoint): Use
get_probe_address.
(add_location_to_breakpoint, bkpt_probe_insert_location)
(bkpt_probe_remove_location): Update.
* breakpoint.h (struct bp_location) <probe>: Now a bound_probe.
* elfread.c (elf_symfile_relocate_probe): Remove.
(elf_probe_fns): Update.
(insert_exception_resume_breakpoint): Change type of "probe"
parameter to bound_probe.
(check_exception_resume): Update.
* objfiles.c (objfile_relocate1): Don't relocate probes.
* probe.c (bound_probe_s): New typedef.
(parse_probes): Use get_probe_address. Set sal's objfile.
(find_probe_by_pc): Return a bound_probe.
(collect_probes): Return a VEC(bound_probe_s).
(compare_probes): Update.
(gen_ui_out_table_header_info): Change type of "probes"
parameter. Update.
(info_probes_for_ops): Update.
(get_probe_address): New function.
(probe_safe_evaluate_at_pc): Update.
* probe.h (struct probe_ops) <get_probe_address>: New field.
<set_semaphore, clear_semaphore>: Add objfile parameter.
(struct probe) <objfile>: Remove field.
<arch>: New field.
<address>: Update comment.
(struct bound_probe): New.
(find_probe_by_pc): Return a bound_probe.
(get_probe_address): Declare.
* solib-svr4.c (struct probe_and_action) <address>: New field.
(hash_probe_and_action, equal_probe_and_action): Update.
(register_solib_event_probe): Add address parameter.
(solib_event_probe_at): Update.
(svr4_create_probe_breakpoints): Add objfile parameter. Use
get_probe_address.
* stap-probe.c (struct stap_probe) <sem_addr>: Update comment.
(stap_get_probe_address): New function.
(stap_can_evaluate_probe_arguments, compute_probe_arg)
(compile_probe_arg): Update.
(stap_set_semaphore, stap_clear_semaphore): Compute semaphore's
address.
(handle_stap_probe): Don't relocate the probe.
(stap_relocate): Remove.
(stap_gen_info_probes_table_values): Update.
(stap_probe_ops): Remove stap_relocate.
* symfile-debug.c (debug_sym_relocate_probe): Remove.
(debug_sym_probe_fns): Update.
* symfile.h (struct sym_probe_fns) <sym_relocate_probe>: Remove.
* symtab.c (init_sal): Use memset.
* symtab.h (struct symtab_and_line) <objfile>: New field.
* tracepoint.c (start_tracing, stop_tracing): Update.
This patch sanitizes the access to gdbarch made by various functions of
the SDT probe API. Before this patch, gdbarch was being accessed via
the probe's objfile; however, this proved to cause a bug on 32-bit ARM
targets because during the parsing of the probe's arguments the code
needed to access some pseudo-registers of the architecture, and this
information is not fully correct on the objfile's gdbarch.
Basically, the approach taken was to instead pass the current/selected
frame to the parsing and evaluation functions, so that they can extract
the gdbarch directly from the frame. It solved the ARM bug reported
above, and also contributed to make the API cleaner.
Tested on x86_64 and 32-bit ARM.
2013-12-11 Sergio Durigan Junior <sergiodj@redhat.com>
* break-catch-throw.c (fetch_probe_arguments): Pass selected frame
to get_probe_argument_count and evaluate_probe_argument.
* probe.c (get_probe_argument_count): Adjust declaration to accept
frame. Pass frame to probe_ops's get_probe_argument_count.
(evaluate_probe_argument): Likewise, for evaluate_probe_argument.
(probe_safe_evaluate_at_pc): Pass frame to
get_probe_argument_count and evaluate_probe_argument.
* probe.h (struct probe_ops) <get_probe_argument_count,
evaluate_probe_argument>: Adjust declarations to accept frame.
(get_probe_argument_count, evaluate_probe_argument): Likewise.
* solib-svr4.c (solib_event_probe_action): Get current frame.
Pass it to get_probe_argument_count.
(svr4_handle_solib_event): Get current frame. Pass it to
get_probe_argument_count and evaluate_probe_argument.
* stap-probe.c (stap_parse_probe_arguments): Adjust declaration to
accept gdbarch. Do not obtain it from the probe's objfile.
(stap_get_probe_argument_count): Adjust declaration to accept
frame. Obtain gdbarch from the frame. Call generic
can_evaluate_probe_arguments. Pass gdbarch to
stap_parse_probe_arguments.
(stap_get_arg): Adjust declaration to accept gdbarch. Pass it to
stap_parse_probe_arguments.
(stap_evaluate_probe_argument): Adjust declaration to accept
frame. Obtain gdbarch from the frame. Pass gdbarch to
stap_get_arg.
(stap_compile_to_ax): Pass agent_expr's gdbarch to stap_get_arg.
(compute_probe_arg): Obtain gdbarch from frame. Pass frame to
get_probe_argument_count and evaluate_probe_argument.
While looking into the probe API, it seemed to me that there were a
number of methods in sym_probe_fns that were not needed. This patch
removes them.
Specifically, it seems to me that sym_probe_fns ought to be concerned
with the API for constructing the probes. Any method relating to some
aspect of an individual probe can be handled via the probe's own
vtable. That is, the double indirection here doesn't seem useful --
it certainly isn't in fact used, but also I couldn't think of a
potential use.
2013-12-06 Tom Tromey <tromey@redhat.com>
* break-catch-throw.c (fetch_probe_arguments): Use
get_probe_argument_count and evaluate_probe_argument.
* elfread.c (elf_get_probe_argument_count)
(elf_can_evaluate_probe_arguments, elf_evaluate_probe_argument)
(elf_compile_to_ax): Remove.
(elf_probe_fns): Update.
* probe.c (get_probe_argument_count, can_evaluate_probe_arguments)
(evaluate_probe_argument): Call method on probe, not via sym
functions.
* stap-probe.c (compute_probe_arg): Use get_probe_argument_count,
evaluate_probe_argument.
(compile_probe_arg): Use get_probe_argument_count. Call method on
probe, not via sym functions.
* symfile-debug.c (debug_sym_get_probe_argument_count)
(debug_can_evaluate_probe_arguments)
(debug_sym_evaluate_probe_argument, debug_sym_compile_to_ax):
Remove.
(debug_sym_probe_fns): Remove.
* symfile.h (struct sym_probe_fns) <sym_get_probe_argument_count,
can_evaluate_probe_arguments, sym_evaluate_probe_argument,
sym_compile_to_ax>: Remove fields.
* breakpoint.c (create_longjmp_master_breakpoint): Check if probe
interface can evaluate arguments. Fallback to the old mode if it
cannot.
(create_exception_master_breakpoint): Likewise.
* elfread.c (elf_can_evaluate_probe_arguments): New function.
(struct sym_probe_fns elf_probe_fns): Export function above to the
probe interface.
* probe.c (can_evaluate_probe_arguments): New function.
* probe.h (struct probe_ops) <can_evaluate_probe_arguments>: New
function pointer.
(can_evaluate_probe_arguments): New function prototype.
* solib-svr4.c (svr4_create_solib_event_breakpoints): Check if
probe interface can evaluate arguments. Fallback to the old mode
if it cannot.
* stap-probe.c (stap_get_probe_argument_count): Check if probe
interface can evaluate arguments. Warning the user if it cannot.
(stap_can_evaluate_probe_arguments): New function.
(struct probe_ops stap_probe_ops): Export function above to the
probe interface.
* symfile.h (struct sym_probe_fns) <can_evaluate_probe_arguments>:
New function pointer.
* probe.h (get_probe_argument_count): New declaration.
(evaluate_probe_argument): Likewise.
* probe.c (get_probe_argument_count): New function.
(evaluate_probe_argument): Likewise.
(probe_safe_evaluate_at_pc): Use the above new functions.
compile_rx_or_error looks like a constructor, but it can return NULL.
This patch changes it to remove the NULL return, making it work
like any other cleanup constructor.
This is a stylistic patch but I think it is also better for code to
follow the normal conventions.
* probe.c (collect_probes): Check arguments for NULL before
calling compile_rx_or_error.
* utils.c (compile_rx_or_error): Require 'rx' to be non-NULL.
Remove NULL return.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
Sergio Durigan Junior