This patch reworks the whole completion machinery, and prepares it
for later enhancements.
Adds a new "completion_tracker" class that is meant to hold everything
about the state of the current completion operation.
This class now has the responsibility of tracking the list of
completion matches, and checking whether the max completions limit has
been reached. You can look at this as this patch starting out by
C++fying the existing "completion_tracker" in symtab.c (it's just an
htab_t typedef currently), moving it to completer.h/c, and then making
it a class/generalizing/enhancing it.
Unlike with the current tracking, completion_tracker now checks
whether the limit has been reached on each completion match list
insertion. This both simplifies the max-completions handling code
(maybe_add_completion_enum is gone, for example), and is a
prerequisite for follow up patches.
The current completion_tracker is only used for symbol completions,
and the symbol code gets at the current instance via globals. This
patch cleans that up by adding a completion_tracker reference to the
signature of the completion functions, and passing the tracker around
everywhere necessary.
Then, the patch changes how the completion match list is handed over
to readline. Currently, we're using the rl_completion_entry_function
readline entry point, and the patch switches to
rl_attempted_completion_function. A following patch will want to let
GDB itself decide the common completion prefix between all matches
(what readline calls the "lowest common denominator"), instead of
having readline compute it, and that's not possible with the
rl_completion_entry_function entry point. Also,
rl_attempted_completion_function lets GDB hand over the match list to
readline as an array in one go instead of passing down matches one by
one, so from that angle it's a nicer entry point anyway.
Lastly, the patch catches exceptions around the readline entry points,
because we can't let C++ exceptions cross readline. We handle that in
the readline input entry point, but the completion entry point isn't
guarded, so GDB can abort if completion throws. E.g., in current
master:
(gdb) b -function "fun<tab>
terminate called after throwing an instance of 'gdb_exception_RETURN_MASK_ERROR'
Aborted (core dumped)
This patch fixes that. This will be exercised in the new tests added
later on in the series.
gdb/ChangeLog:
2017-07-17 Pedro Alves <palves@redhat.com>
* ada-lang.c (symbol_completion_match): Adjust comments.
(symbol_completion_add): Replace vector parameter with
completion_tracker parameter. Use it.
(ada_make_symbol_completion_list): Rename to...
(ada_collect_symbol_completion_matches): ... this. Add
completion_tracker parameter and use it.
(ada_language_defn): Adjust.
* break-catch-syscall.c (catch_syscall_completer): Adjust
prototype and work with completion_tracker instead of VEC.
* breakpoint.c (condition_completer): Adjust prototype and work
with completion_tracker instead of VEC.
* c-lang.c (c_language_defn, cplus_language_defn)
(asm_language_defn, minimal_language_defn): Adjust to renames.
* cli/cli-cmds.c (complete_command): Rework using
completion_tracker. Catch exceptions when completing.
* cli/cli-decode.c (integer_unlimited_completer)
(complete_on_cmdlist, complete_on_enum): Adjust prototype and work
with completion_tracker instead of VEC.
* command.h (struct completion_tracker): Forward declare.
(completer_ftype, completer_handle_brkchars_ftype): Change
types.
(complete_on_cmdlist, complete_on_enum): Adjust.
* completer.c: Include <algorithm>.
(struct gdb_completer_state): New.
(current_completion): New global.
(readline_line_completion_function): Delete.
(noop_completer, filename_completer)
(filename_completer_handle_brkchars, complete_files_symbols)
(linespec_location_completer): Adjust to work with a
completion_tracker instead of a VEC.
(string_or_empty): New.
(collect_explicit_location_matches): Adjust to work with a
completion_tracker instead of a VEC.
(explicit_location_completer): Rename to ...
(complete_explicit_location): ... this and adjust to work with a
completion_tracker instead of a VEC.
(location_completer): Adjust to work with a completion_tracker
instead of a VEC.
(add_struct_fields): Adjust to work with a completion_list instead
of VEC.
(expression_completer): Rename to ...
(complete_expression): ... this and adjust to work with a
completion_tracker instead of a VEC. Use complete_files_symbols.
(expression_completer): Reimplement on top of complete_expression.
(symbol_completer): Adjust to work with a completion_tracker
instead of a VEC.
(enum complete_line_internal_reason): Add describing comments.
(complete_line_internal_normal_command): Adjust to work with a
completion_tracker instead of a VEC.
(complete_line_internal): Rename to ...
(complete_line_internal_1): ... this and adjust to work with a
completion_tracker instead of a VEC. Assert TEXT is NULL in the
handle_brkchars phase.
(new_completion_tracker): Delete.
(complete_line_internal): Reimplement as TRY/CATCH wrapper around
complete_line_internal_1.
(free_completion_tracker): Delete.
(INITIAL_COMPLETION_HTAB_SIZE): New.
(completion_tracker::completion_tracker)
(completion_tracker::~completion_tracker): New.
(maybe_add_completion): Delete.
(completion_tracker::maybe_add_completion)
(completion_tracker::add_completion)
(completion_tracker::add_completions): New.
(throw_max_completions_reached_error): Delete.
(complete_line): Adjust to work with a completion_tracker instead
of a VEC. Don't create a completion_tracker_t or check for max
completions here.
(command_completer, command_completer_handle_brkchars)
(signal_completer, reg_or_group_completer_1)
(reg_or_group_completer, default_completer_handle_brkchars):
Adjust to work with a completion_tracker.
(gdb_completion_word_break_characters_throw): New.
(gdb_completion_word_break_characters): Reimplement.
(line_completion_function): Delete.
(completion_tracker::recompute_lowest_common_denominator)
(expand_preserving_ws)
(completion_tracker::build_completion_result)
(completion_result::completion_result)
(completion_result::completion_result)
(completion_result::~completion_result)
(completion_result::completion_result)
(completion_result::release_match_list, compare_cstrings)
(completion_result::sort_match_list)
(completion_result::reset_match_list)
(gdb_rl_attempted_completion_function_throw)
(gdb_rl_attempted_completion_function): New.
* completer.h (completion_list, struct completion_result)
(class completion_tracker): New.
(complete_line): Add completion_tracker parameter.
(readline_line_completion_function): Delete.
(gdb_rl_attempted_completion_function): New.
(noop_completer, filename_completer, expression_completer)
(location_completer, symbol_completer, command_completer)
(signal_completer, reg_or_group_completer): Update prototypes.
(completion_tracker_t, new_completion_tracker)
(make_cleanup_free_completion_tracker): Delete.
(enum maybe_add_completion_enum): Delete.
(maybe_add_completion): Delete.
(throw_max_completions_reached_error): Delete.
* corefile.c (complete_set_gnutarget): Adjust to work with a
completion_tracker instead of a VEC.
* cp-abi.c (cp_abi_completer): Adjust to work with a
completion_tracker instead of a VEC.
* d-lang.c (d_language_defn): Adjust.
* disasm.c (disassembler_options_completer): Adjust to work with a
completion_tracker instead of a VEC.
* f-lang.c (f_make_symbol_completion_list): Rename to ...
(f_collect_symbol_completion_matches): ... this. Adjust to work
with a completion_tracker instead of a VEC.
(f_language_defn): Adjust.
* go-lang.c (go_language_defn): Adjust.
* guile/scm-cmd.c (cmdscm_add_completion, cmdscm_completer):
Adjust to work with a completion_tracker instead of a VEC.
* infrun.c (handle_completer): Likewise.
* interps.c (interpreter_completer): Likewise.
* interps.h (interpreter_completer): Likewise.
* language.c (unknown_language_defn, auto_language_defn)
(local_language_defn): Adjust.
* language.h (language_defn::la_make_symbol_completion_list):
Rename to ...
(language_defn::la_collect_symbol_completion_matches): ... this
and adjust to work with a completion_tracker instead of a VEC.
* m2-lang.c (m2_language_defn): Adjust.
* objc-lang.c (objc_language_defn): Adjust.
* opencl-lang.c (opencl_language_defn): Adjust.
* p-lang.c (pascal_language_defn): Adjust.
* python/py-cmd.c (cmdpy_completer_helper): Handle NULL word.
(cmdpy_completer_handle_brkchars, cmdpy_completer): Adjust to work
with a completion_tracker.
* rust-lang.c (rust_language_defn): Adjust.
* symtab.c (free_completion_list, do_free_completion_list)
(return_val, completion_tracker): Delete.
(completion_list_add_name, completion_list_add_symbol)
(completion_list_add_msymbol, completion_list_objc_symbol)
(completion_list_add_fields, add_symtab_completions): Add
completion_tracker parameter and use it.
(default_make_symbol_completion_list_break_on_1): Rename to...
(default_collect_symbol_completion_matches_break_on): ... this.
Add completion_tracker parameter and use it instead of allocating
a completion tracker here.
(default_make_symbol_completion_list_break_on): Delete old
implementation.
(default_make_symbol_completion_list): Delete.
(default_collect_symbol_completion_matches): New.
(make_symbol_completion_list): Delete.
(collect_symbol_completion_matches): New.
(make_symbol_completion_type): Rename to ...
(collect_symbol_completion_matches_type): ... this. Add
completion_tracker parameter and use it instead of VEC.
(make_file_symbol_completion_list_1): Rename to...
(collect_file_symbol_completion_matches): ... this. Add
completion_tracker parameter and use it instead of VEC.
(make_file_symbol_completion_list): Delete.
(add_filename_to_list): Use completion_list instead of a VEC.
(add_partial_filename_data::list): Now a completion_list.
(make_source_files_completion_list): Work with a completion_list
instead of a VEC.
* symtab.h: Include "completer.h".
(default_make_symbol_completion_list_break_on)
(default_make_symbol_completion_list, make_symbol_completion_list)
(make_symbol_completion_type, make_file_symbol_completion_list)
(make_source_files_completion_list): Delete.
(default_collect_symbol_completion_matches_break_on)
(default_collect_symbol_completion_matches)
(collect_symbol_completion_matches)
(collect_symbol_completion_matches_type)
(collect_file_symbol_completion_matches)
(make_source_files_completion_list): New.
* top.c (init_main): Don't install a rl_completion_entry_function
hook. Install a rl_attempted_completion_function hook instead.
* tui/tui-layout.c (layout_completer): Adjust to work with a
completion_tracker.
* tui/tui-regs.c (tui_reggroup_completer):
* tui/tui-win.c (window_name_completer, focus_completer)
(winheight_completer): Adjust to work with a completion_tracker.
* value.c: Include "completer.h".
(complete_internalvar): Adjust to work with a completion_tracker.
* value.h (complete_internalvar): Likewise.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
This patch adds asserts where the value's lval must be lval_register.
This triggers an error in frame_register_unwind because VALUE_REGNUM
is used but value's lval is not lval_register.
This also reveals a design issue in frame_register_unwind, that is
arguments addrp and realnump are mutually exclusive, we either use
addrp (for lval_memory), or use realnump (for lval_register). This
can be done in a separate patch.
gdb:
2016-12-06 Yao Qi <yao.qi@linaro.org>
* frame.c (frame_register_unwind): Set *realnump if *lvalp is
lval_register.
* value.c (deprecated_value_next_frame_id_hack): Assert
value->lval is lval_register.
(deprecated_value_regnum_hack): Likewise.
With the previous change, value.location.address is only valid for
lval_memory. This patch restrict some checking on value.lval on
using address. Since we have a check on VALUE_VAL in
set_value_address, we need to set VALUE_VAL properly before
set_value_address too.
gdb:
2016-11-25 Yao Qi <yao.qi@linaro.org>
* ada-lang.c (ensure_lval): Call set_value_address after setting
VALUE_LVAL.
* elfread.c (elf_gnu_ifunc_resolve_addr): Set VALUE_LVAL to
lval_memory.
(elf_gnu_ifunc_resolver_return_stop): Likewise.
* value.c (value_fn_field): Likewise.
(value_from_contents_and_address_unresolved): Likewise.
(value_from_contents_and_address): Likewise.
(value_address): Check value->lval isn't
lval_memory.
(value_raw_address): Likewise.
(set_value_address): Assert value->lval is lval_memory.
value.regnum and value.next_frame_id are only used for lval_register,
so this patch moves them to union value.location. As a result, when
we copy value, only copy location, don't need to copy regnum and
next_frame_id.
This patch also changes regnum's type to int as there is no space
constraint, so update deprecated_value_regnum_hack return type too.
gdb:
2016-11-28 Yao Qi <yao.qi@linaro.org>
* valops.c (value_slice): Don't set frame id of slice.
* value.c (struct value) <regnum, next_frame_id>: Move them to...
(struct value) <location>: ... here. Update comments.
(allocate_value_lazy): Don't set frame id and regnum.
(deprecated_value_next_frame_id_hack): Adjust.
(deprecated_value_regnum_hack): Adjust.
(value_copy): Don't copy frame id and regnu.
(value_primitive_field): Likewise.
(value_from_component): Likewise.
(deprecated_value_regnum_hack): Return int *.
* value.h (deprecated_value_regnum_hack): Update declaration.
We renamed VALUE_FRAME_ID to VALUE_NEXT_FRAME_ID recently,
https://sourceware.org/ml/gdb-patches/2016-11/msg00018.html
and we should use VALUE_NEXT_FRAME_ID in value_from_component
too.
gdb:
2016-11-22 Yao Qi <yao.qi@linaro.org>
* value.c (value_from_component): Use VALUE_NEXT_FRAME_ID
instead of VALUE_FROM_ID.
Nowadays, we create a value of subobject in pretty printer with 'address'
being used,
value = value_from_contents_and_address (type, valaddr + embedded_offset,
address + embedded_offset);
set_value_component_location (value, val);
/* set_value_component_location resets the address, so we may
need to set it again. */
if (VALUE_LVAL (value) != lval_internalvar
&& VALUE_LVAL (value) != lval_internalvar_component
&& VALUE_LVAL (value) != lval_computed)
set_value_address (value, address + embedded_offset);
value_from_contents_and_address creates a value from memory, but the
value we are pretty-printing may not from memory at all.
Instead of using value_from_contents_and_address, we create a value
of subobject with the same location as object's but different offset.
We avoid using address in this way. As a result, parameter 'address'
in apply_val_pretty_printer is no longer needed, we can remove it in
next step.
We've already had the location of the 'whole' value, so it is safe
to assume we can create a value of 'component' or 'suboject' value
at the same location but with different offset.
gdb:
2016-11-21 Yao Qi <yao.qi@linaro.org>
* guile/scm-pretty-print.c (gdbscm_apply_val_pretty_printer):
Don't call value_from_contents_and_address and
set_value_address. Call value_from_component.
* python/py-prettyprint.c (gdbpy_apply_val_pretty_printer):
Likewise.
* value.c (value_from_component): New function.
* value.h (value_from_component): Likewise.
* valarith.c (value_subscripted_rvalue): Call
value_from_component.
The VALUE_FRAME_ID macro provides access to a member in struct value
that's used to hold the frame id that's used when determining a
register's value or when assigning to a register. The underlying
member has a long and obscure name. I won't refer to it here, but
will simply refer to VALUE_FRAME_ID as if it's the struct value member
instead of being a convenient macro.
At the moment, without this patch in place, VALUE_FRAME_ID is set in
value_of_register_lazy() and several other locations to hold the frame
id of the frame passed to those functions.
VALUE_FRAME_ID is used in the lval_register case of
value_fetch_lazy(). To fetch the register's value, it calls
get_frame_register_value() which, in turn, calls
frame_unwind_register_value() with frame->next.
A python based unwinder may wish to determine the value of a register
or evaluate an expression containing a register. When it does this,
value_fetch_lazy() will be called under some circumstances. It will
attempt to determine the frame id associated with the frame passed to
it. In so doing, it will end up back in the frame sniffer of the very
same python unwinder that's attempting to learn the value of a
register as part of the sniffing operation. This recursion is not
desirable.
As noted above, when value_fetch_lazy() wants to fetch a register's
value, it does so (indirectly) by unwinding from frame->next.
With this in mind, a solution suggests itself: Change VALUE_FRAME_ID
to hold the frame id associated with the next frame. Then, when it
comes time to obtain the value associated with the register, we can
simply unwind from the frame corresponding to the frame id stored in
VALUE_FRAME_ID. This neatly avoids the python unwinder recursion
problem by changing when the "next" operation occurs. Instead of the
"next" operation occuring when the register value is fetched, it
occurs earlier on when assigning a frame id to VALUE_FRAME_ID.
(Thanks to Pedro for this suggestion.)
This patch implements this idea.
It builds on the patch "Distinguish sentinel frame from null frame".
Without that work in place, it's necessary to check for null_id at
several places and then obtain the sentinel frame.
It also renames most occurences of VALUE_FRAME_ID to
VALUE_NEXT_FRAME_ID to reflect the new meaning of this field.
There are several uses of VALUE_FRAME_ID which were not changed. In
each case, the original meaning of VALUE_FRAME_ID is required to get
correct results. In all but one of these uses, either
put_frame_register_bytes() or get_frame_register_bytes() is being
called with the frame value obtained from VALUE_FRAME_ID. Both of
these functions perform some unwinding by performing a "->next"
operation on the frame passed to it. If we were to use the new
VALUE_NEXT_FRAME_ID macro, this would effectively do two "->next"
operations, which is not what we want.
The VALUE_FRAME_ID macro has been redefined in terms of
VALUE_NEXT_FRAME_ID. It simply fetches the previous frame's id,
providing this id as the value of the macro.
gdb/ChangeLog:
* value.h (VALUE_FRAME_ID): Rename to VALUE_NEXT_FRAME_ID. Update
comment. Create new VALUE_FRAME_ID which is defined in terms of
VALUE_NEXT_FRAME_ID.
(deprecated_value_frame_id_hack): Rename to
deprecated_value_next_frame_id_hack.
* dwarf2loc.c, findvar.c, frame-unwind.c, sentinel-frame.c,
valarith.c, valops.c, value.c: Adjust nearly all occurences of
VALUE_FRAME_ID to VALUE_NEXT_FRAME_ID. Add comments for those
which did not change.
* value.c (struct value): Rename frame_id field to next_frame_id.
Update comment.
(deprecated_value_frame_id_hack): Rename to
deprecated_value_next_frame_id_hack.
(value_fetch_lazy): Call frame_unwind_register_value()
instead of get_frame_register_value().
* frame.c (get_prev_frame_id_by_id): New function.
* frame.h (get_prev_frame_id_by_id): Declare.
* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Make
VALUE_NEXT_FRAME_ID refer to the next frame.
* findvar.c (value_of_register_lazy): Likewise.
(default_value_from_register): Likewise.
(value_from_register): Likewise.
* frame_unwind.c (frame_unwind_got_optimized): Likewise.
* sentinel-frame.c (sentinel_frame_prev_register): Likewise.
* value.h (VALUE_FRAME_ID): Update comment describing this macro.
This patch makes parse_expression and friends return a unique_ptr
instead of raw pointer [1]:
typedef gdb::unique_malloc_ptr<expression> expression_up;
and then adjusts the codebase throughout to stop using cleanups to
manage lifetime of expression pointers.
Whenever I found a structure owning an expression pointer, I made it
store a unique_ptr instead of a raw pointer, which then requires using
new/delete of the holding structure, instead of XNEW/xfree.
[1] - I'd like to set the rule that types named with an "_up" suffix
are unique_ptr typedefs.
Note I used gdb::unique_xmalloc_ptr instead of gdb::unique_ptr, simply
because we still use xmalloc instead of new to allocate expression
objects. Once that's changed, all we need to do is change the
expression_up typedef and the smart pointer will then call delete
instead of xfree.
gdb/ChangeLog:
2016-11-08 Pedro Alves <palves@redhat.com>
* ada-lang.c (ada_read_renaming_var_value): Use expression_up.
(struct ada_catchpoint_location) <excep_cond_expr>: Now an
expression_up.
(ada_catchpoint_location_dtor): Reset excep_cond_expr instead of
using xfree.
(create_excep_cond_exprs): Use expression_up and gdb::move.
(allocate_location_exception): Use new instead of XNEW.
(should_stop_exception): Likewise. Adjust to use expression_up.
(create_ada_exception_catchpoint): Use new instead of XNEW.
* ax-gdb.c (agent_eval_command_one): Use expression_up instead of
cleanups.
(maint_agent_printf_command): Use expression_up.
* break-catch-sig.c (create_signal_catchpoint): Use new instead of
XNEW.
* break-catch-syscall.c (create_syscall_event_catchpoint):
Likewise.
* break-catch-throw.c (handle_gnu_v3_exceptions): Use new instead
of XCNEW. Use gdb::unique_ptr instead of cleanups.
* breakpoint.c (set_breakpoint_condition, update_watchpoint)
(parse_cmd_to_aexpr, watchpoint_check)
(bpstat_check_breakpoint_conditions, watchpoint_locations_match):
Adjust to use expression_up.
(init_bp_location): Adjust.
(free_bp_location): Use delete instead of xfree.
(set_raw_breakpoint_without_location, set_raw_breakpoint)
(add_solib_catchpoint, create_fork_vfork_event_catchpoint)
(new_single_step_breakpoint, create_breakpoint_sal): Use new
instead of XNEW.
(find_condition_and_thread): Adjust to use expression_up.
(create_breakpoint): Use new instead of XNEW.
(dtor_watchpoint): Don't xfree expression pointers, they're
unique_ptr's now.
(insert_watchpoint, remove_watchpoint): Adjust.
(watch_command_1): Use expression_up. Use new instead of XCNEW.
(catch_exec_command_1): Use new instead of XNEW.
(bp_location_dtor): Don't xfree expression pointers, they're
unique_ptr's now.
(base_breakpoint_allocate_location)
(strace_marker_create_breakpoints_sal): Use new instead of XNEW.
(delete_breakpoint): Use delete instead of xfree.
* breakpoint.h (struct bp_location) <cond>: Now an
unique_ptr<expression> instead of a raw pointer.
(struct watchpoint) <exp, cond_exp>: Likewise.
* cli/cli-script.c (execute_control_command): Use expression_up
instead of cleanups.
* dtrace-probe.c (dtrace_process_dof_probe): Use expression_up.
* eval.c (parse_and_eval_address, parse_and_eval_long)
(parse_and_eval, parse_to_comma_and_eval, parse_and_eval_type):
Use expression_up instead of cleanups.
* expression.h (expression_up): New typedef.
(parse_expression, parse_expression_with_language, parse_exp_1):
Change return type to expression_up.
* mi/mi-main.c (mi_cmd_data_evaluate_expression)
(print_variable_or_computed): Use expression_up.
* objc-lang.c (print_object_command): Use expression_up instead of
cleanups.
* parse.c (parse_exp_1, parse_exp_in_context)
(parse_exp_in_context_1, parse_expression)
(parse_expression_with_language): Return an expression_up instead
of a raw pointer.
(parse_expression_for_completion): Use expression_up.
* printcmd.c (struct display) <exp>: Now an expression_up instead
of a raw pointer.
(print_command_1, output_command_const, set_command, x_command):
Use expression_up instead of cleanups.
(display_command): Likewise. Use new instead of XNEW.
(free_display): Use delete instead of xfree.
(do_one_display): Adjust to use expression_up.
* remote.c (remote_download_tracepoint): Likewise.
* stack.c (return_command): Likewise.
* tracepoint.c (validate_actionline, encode_actions_1): Use
expression_up instead of cleanups.
* typeprint.c (whatis_exp, maintenance_print_type): Likewise.
* value.c (init_if_undefined_command): Likewise.
* varobj.c (struct varobj_root) <exp>: Now an expression_up
instead of a raw pointer.
(varobj_create): Adjust.
(varobj_set_value): Use an expression_up instead of cleanups.
(new_root_variable): Use new instead of XNEW.
(free_variable): Use delete instead of xfree.
(value_of_root_1): Use std::swap.
With something like:
struct A { int bitfield:4; } var;
If 'var' ends up wholly-optimized out, printing 'var.bitfield' crashes
gdb here:
(top-gdb) bt
#0 0x000000000058b89f in extract_unsigned_integer (addr=0x2 <error: Cannot access memory at address 0x2>, len=2, byte_order=BFD_ENDIAN_LITTLE)
at /home/pedro/gdb/mygit/src/gdb/findvar.c:109
#1 0x00000000005a187a in unpack_bits_as_long (field_type=0x16cff70, valaddr=0x0, bitpos=16, bitsize=12) at /home/pedro/gdb/mygit/src/gdb/value.c:3347
#2 0x00000000005a1b9d in unpack_value_bitfield (dest_val=0x1b5d9d0, bitpos=16, bitsize=12, valaddr=0x0, embedded_offset=0, val=0x1b5d8d0)
at /home/pedro/gdb/mygit/src/gdb/value.c:3441
#3 0x00000000005a2a5f in value_fetch_lazy (val=0x1b5d9d0) at /home/pedro/gdb/mygit/src/gdb/value.c:3958
#4 0x00000000005a10a7 in value_primitive_field (arg1=0x1b5d8d0, offset=0, fieldno=0, arg_type=0x16d04c0) at /home/pedro/gdb/mygit/src/gdb/value.c:3161
#5 0x00000000005b01e5 in do_search_struct_field (name=0x1727c60 "bitfield", arg1=0x1b5d8d0, offset=0, type=0x16d04c0, looking_for_baseclass=0, result_ptr=0x7fffffffcaf8,
[...]
unpack_value_bitfield is already optimized-out/unavailable -aware:
(...) VALADDR points to the contents of VAL. If the VAL's contents
required to extract the bitfield from are unavailable/optimized
out, DEST_VAL is correspondingly marked unavailable/optimized out.
however, it is not considering the case of the value having no
contents buffer at all, as can happen through
allocate_optimized_out_value.
gdb/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
* value.c (unpack_value_bitfield): Skip unpacking if the parent
has no contents buffer to begin with.
gdb/testsuite/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
* gdb.dwarf2/bitfield-parent-optimized-out.exp: New file.
GDB computes structure byte offsets using a 32 bit integer. And,
first it computes the offset in bits and then converts to bytes. The
result is that any offset that if 512K bytes or larger overflows.
This patch changes GDB to use LONGEST for such calculations.
PR gdb/17520 Structure offset wrong when 1/4 GB or greater.
* c-lang.h: Change all parameters, variables, and struct or union
members used as struct or union fie3ld offsets from int to
LONGEST.
* c-valprint.c: Likewise.
* cp-abi.c: Likewise.
* cp-abi.h: Likewise.
* cp-valprint.c: Likewise.
* d-valprint.c: Likewise.
* dwarf2loc.c: Likewise.
* eval.c: Likewise.
* extension-priv.h: Likewise.
* extension.c: Likewise.
* extension.h: Likewise.
* findvar.c: Likewise.
* gdbtypes.h: Likewise.
* gnu-v2-abi.c: Likewise.
* gnu-v3-abi.c: Likewise.
* go-valprint.c: Likewise.
* guile/guile-internal.h: Likewise.
* guile/scm-pretty-print.c: Likewise.
* jv-valprint.c Likewise.
* opencl-lang.c: Likewise.
* p-lang.h: Likewise.
* python/py-prettyprint.c: Likewise.
* python/python-internal.h: Likewise.
* spu-tdep.c: Likewise.
* typeprint.c: Likewise.
* valarith.c: Likewise.
* valops.c: Likewise.
* valprint.c: Likewise.
* valprint.h: Likewise.
* value.c: Likewise.
* value.h: Likewise.
* p-valprint.c: Likewise.
* c-typeprint.c (c_type_print_base): When printing offset, use
plongest, not %d.
* gdbtypes.c (recursive_dump_type): Ditto.
Fortran supports dynamic types for which bounds, size and location
can vary during their lifetime. As a result of the dynamic
behaviour, they have to be resolved at every query.
This patch will resolve the type of a structure field when it
is dynamic.
2016-04-26 Bernhard Heckel <bernhard.heckel@intel.com>
2016-04-26 Keven Boell <keven.boell@intel.com>
Before:
(gdb) print threev%ivla(1)
Cannot access memory at address 0x3
(gdb) print threev%ivla(5)
no such vector element
After:
(gdb) print threev%ivla(1)
$9 = 1
(gdb) print threev%ivla(5)
$10 = 42
gdb/Changelog:
* NEWS: Add new supported features for fortran.
* gdbtypes.c (remove_dyn_prop): New.
(resolve_dynamic_struct): Keep type length for fortran structs.
* gdbtypes.h: Forward declaration of new function.
* value.c (value_address): Return dynamic resolved location of a value.
(set_value_component_location): Adjust the value address
for single value prints.
(value_primitive_field): Support value types with a dynamic location.
(set_internalvar): Remove dynamic location property of
internal variables.
gdb/testsuite/Changelog:
* gdb.fortran/vla-type.f90: New file.
* gdb.fortran/vla-type.exp: New file.
On:
$ uname -a
NetBSD gcc70.fsffrance.org 5.1 NetBSD 5.1 (GENERIC) #0: Sat Nov 6 13:19:33 UTC 2010 builds@b6.netbsd.org:/home/builds/ab/netbsd-5-1-RELEASE/amd64/201011061943Z-obj/home/builds/ab/netbsd-5-1-RELEASE/src/sys/arch/amd64/compile/GENERIC amd64
With:
$ g++ -v
Using built-in specs.
Target: x86_64--netbsd
Configured with: /usr/src/tools/gcc/../../gnu/dist/gcc4/configure --enable-long-long --disable-multilib --enable-threads --disable-symvers --build=x86_64-unknown-netbsd4.99.72 --host=x86_64--netbsd --target=x86_64--netbsd --enable-__cxa_atexit
Thread model: posix
gcc version 4.1.3 20080704 prerelease (NetBSD nb2 20081120)
I saw:
../../src/gdb/ada-typeprint.c: In function 'void print_fixed_point_type(type*, ui_file*)':
../../src/gdb/ada-typeprint.c:366: warning: passing 'float' for argument 2 to 'DOUBLEST ada_fixed_to_float(type*, LONGEST)'
../../src/gdb/value.c: In function 'LONGEST unpack_long(type*, const gdb_byte*)':
../../src/gdb/value.c:2833: warning: converting to 'LONGEST' from 'DOUBLEST'
../../src/gdb/value.c:2838: warning: converting to 'LONGEST' from 'DOUBLEST'
gdb/ChangeLog:
2016-04-14 Pedro Alves <palves@redhat.com>
* ada-typeprint.c (print_fixed_point_type): Don't pass float as
argument to function expecting LONGEST.
* value.c (unpack_long): Add casts to LONGEST.
I did a quick pass over value.c and value.h and made some of the accessor methods'
pass-by-reference parameters const-correct. Besides the obvious benefits, this is
required if we want to use them on values that are already declared as const
(such as the parameters to lval_funcs).
There's probably a lot more stuff that can be made const, here and elsewhere.
gdb/ChangeLog:
2016-04-08 Martin Galvan <martin.galvan@tallertechnologies.com>
* value.c (value_next): Make pass-by-reference parameters const-correct.
(value_parent): Likewise.
(value_enclosing_type): Likewise.
(value_lazy): Likewise.
(value_stack): Likewise.
(value_embedded_offset): Likewise.
(value_pointed_to_offset): Likewise.
(value_raw_address): Likewise.
(deprecated_value_modifiable): Likewise.
(value_free_to_mark): Likewise.
(value_release_to_mark): Likewise.
(internalvar_name): Likewise.
(readjust_indirect_value_type): Likewise.
(value_initialized): Likewise.
* value.h (value_next): Likewise.
(value_parent): Likewise.
(value_enclosing_type): Likewise.
(value_lazy): Likewise.
(value_stack): Likewise.
(value_embedded_offset): Likewise.
(value_pointed_to_offset): Likewise.
(value_raw_address): Likewise.
(deprecated_value_modifiable): Likewise.
(value_free_to_mark): Likewise.
(value_release_to_mark): Likewise.
(internalvar_name): Likewise.
(readjust_indirect_value_type): Likewise.
(value_initialized): Likewise.
This patch eliminates an error thrown when accessing the value of a
pointer to a structure where the pointer has been optimized out and
'set print object' is 'on'. The error shows up as the rather ugly
value of the pointer variable in Eclipse.
If 'set print object' is 'on', GDB tries to determine the actual
(derived) type of the object rather than the declared type, which
requires dereferencing the pointer, which in this cases throws an
error because the pointer has been optimized out.
The fix is to simply ignore the 'print object on' setting for
pointers or references to structures when they have been optimized
out. This means we just get the declared type instead of the actual
type, because in this case that's the best that we can do.
To implement the fix, value_optimized_out was modified so that it
no longer throws an error when it fails to fetch the specified
value. Instead, it just checks value->optimized_out. If we can't
definitively say that the value is optimized out, then we assume
it is not.
gdb/ChangeLog:
2016-04-06 Don Breazeal <donb@codesourcery.com>
* value.c (value_actual_type): Don't try to get rtti type
of the value if it has been optimized out.
(value_optimized_out): If a memory access error occurs,
just check vaue->optimized_out.
For languages with dynamic types, an incorrect program, or uninitialised
variables within a program, could result in an incorrect, overly large
type being associated with a value. Currently, attempting to print such
a variable will result in gdb trying to allocate an overly large buffer.
If this large memory allocation fails then the result can be gdb either
terminating, or (due to memory contention) becoming unresponsive for the
user.
A new user visible variable in gdb helps guard against such problems,
two new commands are available:
set max-value-size
show max-value-size
The 'max-value-size' is the maximum size of memory in bytes that gdb
will allocate for the contents of a value. Any attempt to allocate a
value with a size greater than this will result in an error. The
initial default for this limit is set at 64k, this is based on a similar
limit that exists within the ada specific code.
It is possible for the user to set max-value-size to unlimited, in which
case the old behaviour is restored.
gdb/ChangeLog:
* value.c (max_value_size): New variable.
(MIN_VALUE_FOR_MAX_VALUE_SIZE): New define.
(show_max_value_size): New function.
(check_type_length_before_alloc): New function.
(allocate_value_contents): Call check_type_length_before_alloc.
(set_value_enclosing_type): Likewise.
(_initialize_values): Add set/show handler for max-value-size.
* NEWS: Mention new set/show command.
gdb/doc/ChangeLog:
* gdb.texinfo (Value Sizes): New section.
(Data): Add the 'Value Sizes' node to the menu.
gdb/testsuite/ChangeLog:
* gdb.base/max-value-size.c: New file.
* gdb.base/max-value-size.exp: New file.
* gdb.base/huge.exp: Disable max-value-size for this test.
As Pedro suggested on gdb-patches@ (see
https://sourceware.org/ml/gdb-patches/2015-05/msg00714.html), this
change makes symbol lookup functions return a structure that includes
both the symbol found and the block in which it was found. This makes
it possible to get rid of the block_found global variable and thus makes
block hunting explicit.
gdb/
* ada-exp.y (write_object_renaming): Replace struct
ada_symbol_info with struct block_symbol. Update field
references accordingly.
(block_lookup, select_possible_type_sym): Likewise.
(find_primitive_type): Likewise. Also update call to
ada_lookup_symbol to extract the symbol itself.
(write_var_or_type, write_name_assoc): Likewise.
* ada-lang.h (struct ada_symbol_info): Remove.
(ada_lookup_symbol_list): Replace struct ada_symbol_info with
struct block_symbol.
(ada_lookup_encoded_symbol, user_select_syms): Likewise.
(ada_lookup_symbol): Return struct block_symbol instead of a
mere symbol.
* ada-lang.c (defns_collected): Replace struct ada_symbol_info
with struct block_symbol.
(resolve_subexp, ada_resolve_function, sort_choices,
user_select_syms, is_nonfunction, add_defn_to_vec,
num_defns_collected, defns_collected,
symbols_are_identical_enums, remove_extra_symbols,
remove_irrelevant_renamings, add_lookup_symbol_list_worker,
ada_lookup_symbol_list, ada_iterate_over_symbols,
ada_lookup_encoded_symbol, get_var_value): Likewise.
(ada_lookup_symbol): Return a block_symbol instead of a mere
symbol. Replace struct ada_symbol_info with struct
block_symbol.
(ada_lookup_symbol_nonlocal): Likewise.
(standard_lookup): Make block passing explicit through
lookup_symbol_in_language.
* ada-tasks.c (get_tcb_types_info): Update the calls to
lookup_symbol_in_language to extract the mere symbol out of the
returned value.
(ada_tasks_inferior_data_sniffer): Likewise.
* ax-gdb.c (gen_static_field): Likewise for the call to
lookup_symbol.
(gen_maybe_namespace_elt): Deal with struct symbol_in_block from
lookup functions.
(gen_expr): Likewise.
* c-exp.y: Likewise. Remove uses of block_found.
(lex_one_token, classify_inner_name, c_print_token): Likewise.
(classify_name): Likewise. Rename the "sym" local variable to
"bsym".
* c-valprint.c (print_unpacked_pointer): Likewise.
* compile/compile-c-symbols.c (convert_symbol_sym): Promote the
"sym" parameter from struct symbol * to struct block_symbol.
Use it to remove uses of block_found. Deal with struct
symbol_in_block from lookup functions.
(gcc_convert_symbol): Likewise. Update the call to
convert_symbol_sym.
* compile/compile-object-load.c (compile_object_load): Deal with
struct symbol_in_block from lookup functions.
* cp-namespace.c (cp_lookup_nested_symbol_1,
cp_lookup_nested_symbol, cp_lookup_bare_symbol,
cp_search_static_and_baseclasses,
cp_lookup_symbol_in_namespace, cp_lookup_symbol_via_imports,
cp_lookup_symbol_imports_or_template,
cp_lookup_symbol_via_all_imports, cp_lookup_symbol_namespace,
lookup_namespace_scope, cp_lookup_nonlocal,
find_symbol_in_baseclass): Return struct symbol_in_block instead
of mere symbols and deal with struct symbol_in_block from lookup
functions.
* cp-support.c (inspect_type, replace_typedefs,
cp_lookup_rtti_type): Deal with struct symbol_in_block from
lookup functions.
* cp-support.h (cp_lookup_symbol_nonlocal,
cp_lookup_symbol_from_namespace,
cp_lookup_symbol_imports_or_template, cp_lookup_nested_symbol):
Return struct symbol_in_block instead of mere symbols.
* d-exp.y (d_type_from_name, d_module_from_name, push_variable,
push_module_name):
Deal with struct symbol_in_block from lookup functions. Remove
uses of block_found.
* eval.c (evaluate_subexp_standard): Update call to
cp_lookup_symbol_namespace.
* f-exp.y: Deal with struct symbol_in_block from lookup
functions. Remove uses of block_found.
(yylex): Likewise.
* gdbtypes.c (lookup_typename, lookup_struct, lookup_union,
lookup_enum, lookup_template_type, check_typedef): Deal with
struct symbol_in_block from lookup functions.
* guile/scm-frame.c (gdbscm_frame_read_var): Likewise.
* guile/scm-symbol.c (gdbscm_lookup_symbol): Likewise.
(gdbscm_lookup_global_symbol): Likewise.
* gnu-v3-abi.c (gnuv3_get_typeid_type): Likewise.
* go-exp.y: Likewise. Remove uses of block_found.
(package_name_p, classify_packaged_name, classify_name):
Likewise.
* infrun.c (insert_exception_resume_breakpoint): Likewise.
* jv-exp.y (push_variable): Likewise.
* jv-lang.c (java_lookup_class, get_java_object_type): Likewise.
* language.c (language_bool_type): Likewise.
* language.h (struct language_defn): Update
la_lookup_symbol_nonlocal to return a struct symbol_in_block
rather than a mere symbol.
* linespec.c (find_label_symbols): Deal with struct
symbol_in_block from lookup functions.
* m2-exp.y: Likewise. Remove uses of block_found.
(yylex): Likewise.
* mi/mi-cmd-stack.c (list_args_or_locals): Likewise.
* objc-lang.c (lookup_struct_typedef, find_imps): Likewise.
* p-exp.y: Likewise. Remove uses of block_found.
(yylex): Likewise.
* p-valprint.c (pascal_val_print): Likewise.
* parse.c (write_dollar_variable): Likewise. Remove uses of
block_found.
* parser-defs.h (struct symtoken): Turn the SYM field into a
struct symbol_in_block.
* printcmd.c (address_info): Deal with struct symbol_in_block
from lookup functions.
* python/py-frame.c (frapy_read_var): Likewise.
* python/py-symbol.c (gdbpy_lookup_symbol,
gdbpy_lookup_global_symbol): Likewise.
* skip.c (skip_function_command): Likewise.
* solib-darwin.c (darwin_lookup_lib_symbol): Return a struct
symbol_in_block instead of a mere symbol.
* solib-spu.c (spu_lookup_lib_symbol): Likewise.
* solib-svr4.c (elf_lookup_lib_symbol): Likewise.
* solib.c (solib_global_lookup): Likewise.
* solist.h (solib_global_lookup): Likewise.
(struct target_so_ops): Update lookup_lib_global_symbol to
return a struct symbol_in_block rather than a mere symbol.
* source.c (select_source_symtab): Deal with struct
symbol_in_block from lookup functions.
* stack.c (print_frame_args, iterate_over_block_arg_vars):
Likewise.
* symfile.c (set_initial_language): Likewise.
* symtab.c (SYMBOL_LOOKUP_FAILED): Turn into a struct
symbol_in_block.
(SYMBOL_LOOKUP_FAILED_P): New predicate as a macro.
(struct symbol_cache_slot): Turn the FOUND field into a struct
symbol_in_block.
(block_found): Remove.
(eq_symbol_entry): Update to deal with struct symbol_in_block in
cache slots.
(symbol_cache_lookup): Return a struct symbol_in_block rather
than a mere symbol.
(symbol_cache_mark_found): Add a BLOCK parameter to fill
appropriately the cache slots. Update callers.
(symbol_cache_dump): Update cache slots handling to the type
change.
(lookup_symbol_in_language, lookup_symbol, lookup_language_this,
lookup_symbol_aux, lookup_local_symbol,
lookup_symbol_in_objfile, lookup_global_symbol_from_objfile,
lookup_symbol_in_objfile_symtabs,
lookup_symbol_in_objfile_from_linkage_name,
lookup_symbol_via_quick_fns, basic_lookup_symbol_nonlocal,
lookup_symbol_in_static_block, lookup_static_symbol,
lookup_global_symbol):
Return a struct symbol_in_block rather than a mere symbol. Deal
with struct symbol_in_block from other lookup functions. Remove
uses of block_found.
(lookup_symbol_in_block): Remove uses of block_found.
(struct global_sym_lookup_data): Turn the RESULT field into a
struct symbol_in_block.
(lookup_symbol_global_iterator_cb): Update references to the
RESULT field.
(search_symbols): Deal with struct symbol_in_block from lookup
functions.
* symtab.h (struct symbol_in_block): New structure.
(block_found): Remove.
(lookup_symbol_in_language, lookup_symbol,
basic_lookup_symbol_nonlocal, lookup_symbol_in_static_block,
looku_static_symbol, lookup_global_symbol,
lookup_symbol_in_block, lookup_language_this,
lookup_global_symbol_from_objfile): Return a struct
symbol_in_block rather than just a mere symbol. Update comments
to remove mentions of block_found.
* valops.c (find_function_in_inferior,
value_struct_elt_for_reference, value_maybe_namespace_elt,
value_of_this): Deal with struct symbol_in_block from lookup
functions.
* value.c (value_static_field, value_fn_field): Likewise.
This patch updates various value handling functions to make them
consider the addressable memory unit size of the current architecture.
This allows to correctly extract and print values on architectures whose
addressable memory unit is not 8 bits.
The patch doesn't cover all the code that would ideally need to be
adjusted, only the code paths that we happen to use, plus a few obvious
ones. Specifically, those areas are not covered by this patch:
- Management of unavailable bits
- Bitfields
- C++ stuff
Regression-tested on x86-64 Ubuntu 14.04. I saw no related test result
change.
gdb/ChangeLog:
* c-valprint.c (c_val_print_array): Consider addressable memory
unit size.
(c_val_print_ptr): Likewise.
(c_val_print_int): Likewise.
* findvar.c (read_frame_register_value): Likewise.
* valarith.c (find_size_for_pointer_math): Likewise.
(value_ptrdiff): Likewise.
(value_subscripted_rvalue): Likewise.
* valops.c (read_value_memory): Likewise (and rename variables).
(value_assign): Likewise.
(value_repeat): Likewise.
(value_array): Likewise.
(value_slice): Likewise.
* valprint.c (generic_val_print_ptr): Likewise.
(generic_val_print_enum): Likewise.
(generic_val_print_bool): Likewise.
(generic_val_print_int): Likewise.
(generic_val_print_char): Likewise.
(generic_val_print_float): Likewise.
(generic_val_print_decfloat): Likewise.
(generic_val_print_complex): Likewise.
(val_print_scalar_formatted): Likewise.
(val_print_array_elements): Likewise.
* value.c (set_value_parent): Likewise.
(value_contents_copy_raw): Likewise.
(set_internalvar_component): Likewise.
(value_primitive_field): Likewise.
(value_fetch_lazy): Likewise.
* value.h (read_value_memory): Update comment.
Similar to get_type_arch, used to get the gdbarch associated to a
struct value.
gdb/ChangeLog:
* value.c (get_value_arch): New function.
* value.h (get_value_arch): New declaration.
The comment for value_fetch_lazy seems outdated. It says that it's only
called from the value_contents and value_contents_all (macros!), which
is not true. Also, the return value seems useless now, despite what the
comment says.
gdb/ChangeLog:
* value.c (value_fetch_lazy): Update comment, change return
value to void.
* value.h (value_fetch_lazy): Change return value to void.
This is the second part of enhancing the debugger to print the value
of arrays of records whose size is variable when only standard DWARF
info is available (no GNAT encoding). For instance:
subtype Small_Type is Integer range 0 .. 10;
type Record_Type (I : Small_Type := 0) is record
S : String (1 .. I);
end record;
type Array_Type is array (Integer range <>) of Record_Type;
A1 : Array_Type := (1 => (I => 0, S => <>),
2 => (I => 1, S => "A"),
3 => (I => 2, S => "AB"));
Currently, GDB prints the following output:
(gdb) p a1
$1 = (
The error happens while the ada-valprint module is trying to print
the value of an element of our array. Because of the fact that
the array's element (type Record_Type) has a variant size, the DWARF
info for our array provide the array's stride:
<1><749>: Abbrev Number: 10 (DW_TAG_array_type)
<74a> DW_AT_name : (indirect string, offset: 0xb6d): pck__T18s
<74e> DW_AT_byte_stride : 16
<74f> DW_AT_type : <0x6ea>
And because our array has a stride, ada-valprint treats it the same
way as packed arrays (see ada-valprint.c::ada_val_print_array):
if (TYPE_FIELD_BITSIZE (type, 0) > 0)
val_print_packed_array_elements (type, valaddr, offset_aligned,
0, stream, recurse,
original_value, options);
The first thing that we should notice in the call above is that
the "valaddr" buffer and the associated offset (OFFSET_ALIGNED)
is passed, but that the corresponding array's address is not.
This can be explained by looking inside val_print_packed_array_elements,
where we see that the function unpacks each element of our array from
the buffer alone (ada_value_primitive_packed_val), and then prints
the resulting artificial value instead:
v0 = ada_value_primitive_packed_val (NULL, valaddr + offset,
(i0 * bitsize) / HOST_CHAR_BIT,
(i0 * bitsize) % HOST_CHAR_BIT,
bitsize, elttype);
[...]
val_print (elttype, value_contents_for_printing (v0),
value_embedded_offset (v0), 0, stream,
recurse + 1, v0, &opts, current_language);
Of particular interest, here, is the fact that we call val_print
with a null address, which is OK, since we're providing a buffer
instead (value_contents_for_printing). Also, providing an address
might not always possible, since packing could place elements at
boundaries that are not byte-aligned.
Things go south when val_print tries to see if there is a pretty-printer
that could be applied. In particular, one of the first things that
the Python pretty-printer does is to create a value using our buffer,
and the given address, which in this case is null (see call to
value_from_contents_and_address in gdbpy_apply_val_pretty_printer).
value_from_contents_and_address, in turn immediately tries to resolve
the type, using the given address, which is null. But, because our
array element is a record containing an array whose bound is the value
of one of its elements (the "s" component), the debugging info for
the array's upper bound is a reference...
<3><71a>: Abbrev Number: 7 (DW_TAG_subrange_type)
<71b> DW_AT_type : <0x724>
<71f> DW_AT_upper_bound : <0x703>
... to component "i" of our record...
<2><703>: Abbrev Number: 5 (DW_TAG_member)
<704> DW_AT_name : i
<706> DW_AT_decl_file : 2
<707> DW_AT_decl_line : 6
<708> DW_AT_type : <0x6d1>
<70c> DW_AT_data_member_location: 0
... where that component is located at offset 0 of the start
of the record. dwarf2_evaluate_property correctly determines
the offset where to load the value of the bound from, but then
tries to read that value from inferior memory using the address
that was given, which is null. See case PROP_ADDR_OFFSET in
dwarf2_evaluate_property:
val = value_at (baton->offset_info.type,
pinfo->addr + baton->offset_info.offset);
This triggers a memory error, which then causes the printing to terminate.
Since there are going to be situations where providing an address
alone is not going to be sufficient (packed arrays where array elements
are not stored at byte boundaries), this patch fixes the issue by
enhancing the type resolution to take both address and data. This
follows the same principle as the val_print module, where both
address and buffer ("valaddr") can be passed as arguments. If the data
has already been fetched from inferior memory (or provided by the
debugging info in some form -- Eg a constant), then use that data
instead of reading it from inferior memory.
Note that this should also be a good step towards being able to handle
dynamic types whose value is stored outside of inferior memory
(Eg: in a register).
With this patch, GDB isn't able to print all of A1, but does perform
a little better:
(gdb) p a1
$1 = ((i => 0, s => , (i => 1, s => , (i => 2, s => )
There is another issue which is independent of this one, and will
therefore be patched separately.
gdb/ChangeLog:
* dwarf2loc.h (struct property_addr_info): Add "valaddr" field.
* dwarf2loc.c (dwarf2_evaluate_property): Add handling of
pinfo->valaddr.
* gdbtypes.h (resolve_dynamic_type): Add "valaddr" parameter.
* gdbtypes.c (resolve_dynamic_struct): Set pinfo.valaddr.
(resolve_dynamic_type_internal): Set pinfo.valaddr.
Add handling of addr_stack->valaddr.
(resolve_dynamic_type): Add "valaddr" parameter.
Set pinfo.valaddr field.
* ada-lang.c (ada_discrete_type_high_bound): Update call to
resolve_dynamic_type.
(ada_discrete_type_low_bound): Likewise.
* findvar.c (default_read_var_value): Likewise.
* value.c (value_from_contents_and_address): Likewise.
This patch splits the TRY_CATCH macro into three, so that we go from
this:
~~~
volatile gdb_exception ex;
TRY_CATCH (ex, RETURN_MASK_ERROR)
{
}
if (ex.reason < 0)
{
}
~~~
to this:
~~~
TRY
{
}
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
~~~
Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.
This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.
TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:
TRY
{
}
// some code here.
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
Just like it isn't valid to do that with C++'s native try/catch.
By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.
The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved. After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch]. The result was folded into this patch so that GDB
still builds at each incremental step.
END_CATCH is necessary for two reasons:
First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:
#define CATCH(EXCEPTION, mask) \
for (struct gdb_exception EXCEPTION; \
exceptions_state_mc_catch (&EXCEPTION, MASK); \
EXCEPTION = exception_none)
would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.
Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow. That will
be done in END_CATCH.
After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.
IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.
gdb/ChangeLog.
2015-03-07 Pedro Alves <palves@redhat.com>
* common/common-exceptions.c (struct catcher) <exception>: No
longer a pointer to volatile exception. Now an exception value.
<mask>: Delete field.
(exceptions_state_mc_init): Remove all parameters. Adjust.
(exceptions_state_mc): No longer pop the catcher here.
(exceptions_state_mc_catch): New function.
(throw_exception): Adjust.
* common/common-exceptions.h (exceptions_state_mc_init): Remove
all parameters.
(exceptions_state_mc_catch): Declare.
(TRY_CATCH): Rename to ...
(TRY): ... this. Remove EXCEPTION and MASK parameters.
(CATCH, END_CATCH): New.
All callers adjusted.
gdb/gdbserver/ChangeLog:
2015-03-07 Pedro Alves <palves@redhat.com>
Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
instead.
In C, an enum or structure defined inside other structure has global
scope just like it had been defined outside the struct in the first
place. However, in C++, such a nested structure is given a name that
is nested inside the structure. This patch moves such affected
structures/enums out to global scope, so that code using them works
the same in C++ as it works today in C.
gdb/ChangeLog:
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
* dwarf2-frame.c (enum cfa_how_kind, struct
dwarf2_frame_state_reg_info): Move out of struct
dwarf2_frame_state.
* dwarf2read.c (struct tu_stats): Move out of struct
dwarf2_per_objfile.
(struct file_entry): Move out of struct line_header.
(struct nextfield, struct nextfnfield, struct fnfieldlist, struct
typedef_field_list): Move out of struct field_info.
* gdbtypes.h (enum dynamic_prop_kind, union dynamic_prop_data):
Move out of struct dynamic_prop.
(union type_owner, union field_location, struct field, struct
range_bounds, union type_specific): Move out of struct main_type.
(struct fn_fieldlist, struct fn_field, struct typedef_field)
(VOFFSET_STATIC): Move out of struct cplus_struct_type.
(struct call_site_target, union call_site_parameter_u, struct
call_site_parameter): Move out of struct call_site.
* m32c-tdep.c (enum m32c_prologue_kind): Move out of struct
m32c_prologue.
(enum srcdest_kind): Move out of struct srcdest.
* main.c (enum cmdarg_kind): Move out of struct cmdarg.
* prologue-value.h (enum prologue_value_kind): Move out of struct
prologue_value.
* s390-linux-tdep.c (enum s390_abi_kind): Move out of struct
gdbarch_tdep.
* stabsread.c (struct nextfield, struct next_fnfieldlist): Move
out of struct field_info.
* symfile.h (struct other_sections): Move out of struct
section_addr_info.
* symtab.c (struct symbol_cache_slot): Move out struct
block_symbol_cache.
* target-descriptions.c (enum tdesc_type_kind): Move out of
typedef struct tdesc_type.
* tui/tui-data.h (enum tui_line_or_address_kind): Move out of
struct tui_line_or_address.
* value.c (enum internalvar_kind, union internalvar_data): Move
out of struct internalvar.
* xtensa-tdep.h (struct ctype_cache): Move out of struct
gdbarch_tdep.
This patch renames symbols that happen to have names which are
reserved keywords in C++.
Most of this was generated with Tromey's cxx-conversion.el script.
Some places where later hand massaged a bit, to fix formatting, etc.
And this was rebased several times meanwhile, along with re-running
the script, so re-running the script from scratch probably does not
result in the exact same output. I don't think that matters anyway.
gdb/
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
Rename symbols whose names are reserved C++ keywords throughout.
gdb/gdbserver/
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
Rename symbols whose names are reserved C++ keywords throughout.
gdb/ChangeLog:
* eval.c: Include gdbthread.h.
(evaluate_subexp): Enable thread stack temporaries before
evaluating a complete expression and clean them up after the
evaluation is complete.
* gdbthread.h: Include common/vec.h.
(value_ptr): New typedef.
(VEC (value_ptr)): New vector type.
(value_vec): New typedef.
(struct thread_info): Add new fields stack_temporaries_enabled
and stack_temporaries.
(enable_thread_stack_temporaries)
(thread_stack_temporaries_enabled_p, push_thread_stack_temporary)
(get_last_thread_stack_temporary)
(value_in_thread_stack_temporaries): Declare.
* gdbtypes.c (class_or_union_p): New function.
* gdbtypes.h (class_or_union_p): Declare.
* infcall.c (call_function_by_hand): Store return values of class
type as temporaries on stack.
* thread.c (enable_thread_stack_temporaries): New function.
(thread_stack_temporaries_enabled_p, push_thread_stack_temporary)
(get_last_thread_stack_temporary): Likewise.
(value_in_thread_stack_temporaries): Likewise.
* value.c (value_force_lval): New function.
* value.h (value_force_lval): Declare.
gdb/testsuite/ChangeLog:
* gdb.cp/chained-calls.cc: New file.
* gdb.cp/chained-calls.exp: New file.
* gdb.cp/smartp.exp: Remove KFAIL for "p c2->inta".
PR 12526 reports that -location watchpoints against bitfield arguments
trigger false positives when bits around the bitfield, but not the
bitfield itself, are modified.
This happens because -location watchpoints naturally operate at the
byte level, not at the bit level. When the address of a bitfield
lvalue is taken, information about the bitfield (i.e. its offset and
size) is lost in the process.
This information must first be retained throughout the lifetime of the
-location watchpoint. This patch achieves this by adding two new
fields to the watchpoint struct: val_bitpos and val_bitsize. These
fields are set when a watchpoint is first defined in watch_command_1.
They are both equal to zero if the watchpoint is not a -location
watchpoint or if the argument is not a bitfield.
Then these bitfield parameters are used inside update_watchpoint and
watchpoint_check to extract the actual value of the bitfield from the
watchpoint address, with the help of a local helper function
extract_bitfield_from_watchpoint_value.
Finally when creating a HW breakpoint pointing to a bitfield, we
optimize the address and length of the breakpoint. By skipping over
the bytes that don't cover the bitfield, this step reduces the
frequency at which a read watchpoint for the bitfield is triggered.
It also reduces the number of times a false-positive call to
check_watchpoint is triggered for a write watchpoint.
gdb/
PR breakpoints/12526
* breakpoint.h (struct watchpoint): New fields val_bitpos and
val_bitsize.
* breakpoint.c (watch_command_1): Use these fields to retain
bitfield information.
(extract_bitfield_from_watchpoint_value): New function.
(watchpoint_check): Use it.
(update_watchpoint): Use it. Optimize the address and length of a
HW watchpoint pointing to a bitfield.
* value.h (unpack_value_bitfield): New prototype.
* value.c (unpack_value_bitfield): Make extern.
gdb/testsuite/
PR breakpoints/12526
* gdb.base/watch-bitfields.exp: New file.
* gdb.base/watch-bitfields.c: New file.
Git 9a0dc9e3 regressed gdb.dwarf2/pieces-optimized-out.exp, visible on
i686 (the test doesn't run on x86_64):
(gdb) p s
-$1 = {a = 5, b = <optimized out>, c = <optimized out>, d = <optimized out>}
+$1 = {a = 5, b = <optimized out>, c = 0, d = 0}
-(gdb) PASS: gdb.dwarf2/pieces-optimized-out.exp: print s
+(gdb) FAIL: gdb.dwarf2/pieces-optimized-out.exp: print s
The regression was caused by this removal in cp-valprint.c:
@@ -293,12 +293,6 @@ cp_print_value_fields (struct type *type, struct type *real_type,
{
fputs_filtered (_("<synthetic pointer>"), stream);
}
- else if (!value_bits_valid (val,
- TYPE_FIELD_BITPOS (type, i),
- TYPE_FIELD_BITSIZE (type, i)))
- {
- val_print_optimized_out (val, stream);
- }
else
{
struct value_print_options opts = *options;
The idea was that we'd just fallback to calling value_field_bitfield,
which handles unavailable values (in unpack_value_bits_as_long_1) so
should be able to handle optimized out values too. Alas, it doesn't.
This is currently a bit too messy. Instead of teaching
unpack_value_bits_as_long_1 about optimized out bits, let's bite the
bullet and teach the value code to handle partially optimized out
bitfield, by having it unpack a bitfield and then propagate the range
metadata. Turns out the resulting code looks simpler and clearer.
Tested on x86_64 Fedora 20, -m64/-m32.
gdb/ChangeLog:
* value.c (value_ranges_copy_adjusted): New function, factored out
from ...
(value_contents_copy_raw): ... here.
(unpack_value_bits_as_long_1): Rename back to ...
(unpack_bits_as_long): ... this. Remove 'original_value' and
'result' parameters. Change return type to LONGEST.
(unpack_value_bits_as_long): Delete.
(unpack_value_field_as_long_1): Delete.
(unpack_value_field_as_long, unpack_field_as_long): Reimplement.
(unpack_value_bitfield): New function.
(value_field_bitfield): Reimplement using unpack_value_bitfield.
(value_fetch_lazy): Use unpack_value_bitfield.
* value.h (unpack_value_bits_as_long): Delete declaration.
Consider an array described in the debugging information as being
a typedef of an array type for which there is a DW_AT_data_location
attribute. Trying to print the value of that array currently yields
incorrect element values. For instance:
(gdb) print foo.three_tdef
$1 = (6293760, 0, 6293772)
The problem occurs because we check for the data_location attribute
only on the typedef type, whereas we should be checking for the
typedef's target type. As a result, GDB erroneously thinks that
there is no data_location, and therefore starts reading the array's
content from the address of the descriptor instead of the data_location
address.
gdb/ChangeLog:
* value.c (value_from_contents_and_address): Strip resolved_type's
typedef layers before checking its TYPE_DATA_LOCATION.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/data-loc.exp: Add additional tests exercising
the handling of variables declared as a typedef to an array
which a DW_AT_data_location attribute.
This fixes PR symtab/14604, PR symtab/14605, and Jan's test at
https://sourceware.org/ml/gdb-patches/2014-07/msg00158.html, in a tree
with bddbbed reverted:
2014-07-22 Pedro Alves <palves@redhat.com>
* value.c (allocate_optimized_out_value): Don't mark value as
non-lazy.
The PRs are about variables described by the DWARF as being split over
multiple registers using DWARF piece information, but some of those
registers being marked as optimised out (not saved) by a later frame.
GDB currently incorrectly mishandles these partially-optimized-out
values.
Even though we can usually tell from the debug info whether a local or
global is optimized out, handling the case of a local living in a
register that was not saved in a frame requires fetching the variable.
GDB also needs to fetch a value to tell whether parts of it are
"<unavailable>". Given this, it's not worth it to try to avoid
fetching lazy optimized-out values based on debug info alone.
So this patch makes GDB track which chunks of a value's contents are
optimized out like it tracks <unavailable> contents. That is, it
makes value->optimized_out be a bit range vector instead of a boolean,
and removes the struct lval_funcs check_validity and check_any_valid
hooks.
Unlike Andrew's series which this is based on (at
https://sourceware.org/ml/gdb-patches/2013-08/msg00300.html, note some
pieces have gone in since), this doesn't merge optimized out and
unavailable contents validity/availability behind a single interface,
nor does it merge the bit range vectors themselves (at least yet).
While it may be desirable to have a single entry point that returns
existence of contents irrespective of what may make them
invalid/unavailable, several places want to treat optimized out /
unavailable / etc. differently, so each spot that potentially could
use it will need to be careful considered on case-by-case basis, and
best done as a separate change.
This fixes Jan's test, because value_available_contents_eq wasn't
considering optimized out value contents. It does now, and because of
that it's been renamed to value_contents_eq.
A new intro comment is added to value.h describing "<optimized out>",
"<not saved>" and "<unavailable>" values.
gdb/
PR symtab/14604
PR symtab/14605
* ada-lang.c (coerce_unspec_val_to_type): Use
value_contents_copy_raw.
* ada-valprint.c (val_print_packed_array_elements): Adjust.
* c-valprint.c (c_val_print): Use value_bits_any_optimized_out.
* cp-valprint.c (cp_print_value_fields): Let the common printing
code handle optimized out values.
(cp_print_value_fields_rtti): Use value_bits_any_optimized_out.
* d-valprint.c (dynamic_array_type): Use
value_bits_any_optimized_out.
* dwarf2loc.c (entry_data_value_funcs): Remove check_validity and
check_any_valid fields.
(check_pieced_value_bits): Delete and inline ...
(check_pieced_synthetic_pointer): ... here.
(check_pieced_value_validity): Delete.
(check_pieced_value_invalid): Delete.
(pieced_value_funcs): Remove check_validity and check_any_valid
fields.
(read_pieced_value): Use mark_value_bits_optimized_out.
(write_pieced_value): Switch to use
mark_value_bytes_optimized_out.
(dwarf2_evaluate_loc_desc_full): Copy the value contents instead
of assuming the whole value is optimized out.
* findvar.c (read_frame_register_value): Remove special handling
of optimized out registers.
(value_from_register): Use mark_value_bytes_optimized_out.
* frame-unwind.c (frame_unwind_got_optimized): Use
mark_value_bytes_optimized_out.
* jv-valprint.c (java_value_print): Adjust.
(java_print_value_fields): Let the common printing code handle
optimized out values.
* mips-tdep.c (mips_print_register): Remove special handling of
optimized out registers.
* opencl-lang.c (lval_func_check_validity): Delete.
(lval_func_check_any_valid): Delete.
(opencl_value_funcs): Remove check_validity and check_any_valid
fields.
* p-valprint.c (pascal_object_print_value_fields): Let the common
printing code handle optimized out values.
* stack.c (read_frame_arg): Remove special handling of optimized
out values. Fetch both VAL and ENTRYVAL before comparing
contents. Adjust to value_available_contents_eq rename.
* valprint.c (valprint_check_validity)
(val_print_scalar_formatted): Use value_bits_any_optimized_out.
(val_print_array_elements): Adjust.
* value.c (struct value) <optimized_out>: Now a VEC(range_s).
(value_bits_any_optimized_out): New function.
(value_entirely_covered_by_range_vector): New function, factored
out from value_entirely_unavailable.
(value_entirely_unavailable): Reimplement.
(value_entirely_optimized_out): New function.
(insert_into_bit_range_vector): New function, factored out from
mark_value_bits_unavailable.
(mark_value_bits_unavailable): Reimplement.
(struct ranges_and_idx): New struct.
(find_first_range_overlap_and_match): New function, factored out
from value_available_contents_bits_eq.
(value_available_contents_bits_eq): Rename to ...
(value_contents_bits_eq): ... this. Check both unavailable
contents and optimized out contents.
(value_available_contents_eq): Rename to ...
(value_contents_eq): ... this.
(allocate_value_lazy): Remove reference to the old optimized_out
boolean.
(allocate_optimized_out_value): Use
mark_value_bytes_optimized_out.
(require_not_optimized_out): Adjust to check whether the
optimized_out vec is empty.
(ranges_copy_adjusted): New function, factored out from
value_contents_copy_raw.
(value_contents_copy_raw): Also copy the optimized out ranges.
Assert the destination ranges aren't optimized out.
(value_contents_copy): Update comment, remove call to
require_not_optimized_out.
(value_contents_equal): Adjust to check whether the optimized_out
vec is empty.
(set_value_optimized_out, value_optimized_out_const): Delete.
(mark_value_bytes_optimized_out, mark_value_bits_optimized_out):
New functions.
(value_entirely_optimized_out, value_bits_valid): Delete.
(value_copy): Take a VEC copy of the 'optimized_out' field.
(value_primitive_field): Remove special handling of optimized out.
(value_fetch_lazy): Assert that lazy values have no unavailable
regions. Use value_bits_any_optimized_out. Remove some special
handling for optimized out values.
* value.h: Add intro comment about <optimized out> and
<unavailable>.
(struct lval_funcs): Remove check_validity and check_any_valid
fields.
(set_value_optimized_out, value_optimized_out_const): Remove.
(mark_value_bytes_optimized_out, mark_value_bits_optimized_out):
New declarations.
(value_bits_any_optimized_out): New declaration.
(value_bits_valid): Delete declaration.
(value_available_contents_eq): Rename to ...
(value_contents_eq): ... this, and extend comments.
gdb/testsuite/
PR symtab/14604
PR symtab/14605
* gdb.dwarf2/dw2-op-out-param.exp: Remove kfail branches and use
gdb_test.
The given type is expected to always be a TYPE_CODE_PTR, for which
resolve_dynamic_type does nothing. So this patch removes this call.
gdb/ChangeLog:
* value.c (value_from_pointer): Remove use of resolve_dynamic_type.
Adjust code accordingly. Adjust function description comment.
gdb/ChangeLog:
* gdbtypes.h (struct main_type): Add field "data_location".
(TYPE_DATA_LOCATION, TYPE_DATA_LOCATION_BATON)
(TYPE_DATA_LOCATION_ADDR, TYPE_DATA_LOCATION_KIND): New macros.
* gdbtypes.c (is_dynamic_type): Return 1 if the type has
a dynamic data location.
(resolve_dynamic_type): Add DW_AT_data_location handling.
(copy_recursive, copy_type): Copy the data_location information
when present.
* dwarf2read.c (set_die_type): Add DW_AT_data_location handling.
* value.c (value_from_contents_and_address): Add
DW_AT_data_location handling.
This constifies a few functions in cli-utils -- get_number_trailer and
friends -- and then fixes the fallout.
2014-07-30 Tom Tromey <tromey@redhat.com>
* breakpoint.c (map_breakpoint_numbers): Update.
* cli/cli-utils.c (get_number_trailer): Make "pp" const. Update.
(get_number_const): New function.
(get_number): Rewrite using get_number_const.
(init_number_or_range): Make "string" const.
(number_is_in_list): Make "list" const.
* cli/cli-utils.h (get_number_const): Declare.
(struct get_number_or_range_state) <string, end_ptr>: Now const.
(init_number_or_range, number_is_in_list): Update.
* printcmd.c (map_display_numbers): Update.
* value.c (value_from_history_ref): Constify.
* value.h (value_from_history_ref): Update.
Tom Tromey
John Baldwin
Pedro Alves
Artemiy Volkov
Joel Brobecker
Yao Qi
Kevin Buettner
David Taylor
Trevor Saunders
Bernhard Heckel
Martin Galvan
Don Breazeal
Andrew Burgess
Simon Marchi
Pierre-Marie de Rodat
Siva Chandra
Doug Evans
Tom Tromey
Gary Benson
Patrick Palka