I noticed that value_of_register (used for getting values _of_
registers ($pc, $rax, etc.), rather than variables _in_ registers),
kind of builds a franken-value, by propagating the lval and address of
the frame register value, but not the entire location, like necessary
for lval_computed (if some unwinder ever returns that, the resulting
value will misbehave). This gets in the way of printing optimized out
(not saved) lval_registers differently from other optimized out
values, as it doesn't make sure the resulting value is lval_register.
I started out by just doing something like:
- VALUE_LVAL (reg_val) = lval;
- set_value_address (reg_val, addr);
+ VALUE_LVAL (reg_val) = lval_register;
... just like value_of_register_lazy below. That's sufficient to fix
the issue.
Then I noticed this is using frame_register, which we should avoid
nowadays, for it returns elements of a value, but not all that's
sometimes necessary (unavailable-ness is all or nothing with it, for
instance), and considered using get_frame_register_value instead
(which returns a struct value), and value_contents_copy, just like
value_fetch_lazy's handling of lval_register. But at that point, I
realized we might as well just defer all that work to
value_of_register_lazy/value_fetch_lazy...
Doing it this way adds a frame_find_by_id lookup (from within
value_fetch_lazy), while we already have a frame pointer handy in
value_of_register. I considered factoring out the lazy register
fetching out of value_fetch_lazy, into a function that takes a frame
pointer and call that instead, avoiding the lookup, but then it looked
like too much complication for an early optimization, and went back to
keeping it simple.
Tested on x86_64 Fedora 17.
gdb/
2013-09-05 Pedro Alves <palves@redhat.com>
* findvar.c (value_of_register): Rework in terms of
value_of_register_lazy.
I came across a pattern used to construct a value in the following way:
struct value *val = allocate_value_lazy (type);
VALUE_LVAL (val) = lval_memory;
set_value_address (val, address);
Instead we fold the above call into:
value_at_lazy (type, addr);
2013-08-27 Sanimir Agovic <sanimir.agovic@intel.com>
* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Use value_at_lazy instead
of assembling value via allocate_value_lazy and attribute setter.
* findvar.c (default_read_var_value): Use value_at_lazy instead of
assembling value via allocate_value_lazy and attribute setter.
* valops.c (do_search_struct_field): Use value_at_lazy instead of
assembling value via allocate_value_lazy and attribute setter.
Allocate the value as optimized out from the start rather than allocating
a value with contents, and then marking it optimized out.
gdb/
2013-07-04 Pedro Alves <palves@redhat.com>
* findvar.c (value_of_register): Use allocate_optimized_out_value
if the register has been optimized out, instead of
set_value_optimized_out.
* frame-unwind.c (frame_unwind_got_optimized): Use
allocate_optimized_out_value.
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.
gdb/ChangeLog
* findvar.c (read_frame_register_value): Mark the result value as
optimized out if any of the input registers have been optimized out.
gdb/testsuite/ChangeLog
* gdb.dwarf2/dw2-op-out-param.S: New file.
* gdb.dwarf2/dw2-op-out-param.exp: New file.
This patch introduces the "iterate_over_objfiles_in_search_order"
gdbarch method, as well as its default implementation, and converts
the areas where it will matter to using this gdbarch method.
The default method implementation is the only one installed, and
the changes should have no functional impact in terms of behavior.
This only paves the way for the architectures that will need their
own version.
gdb/ChangeLog:
* gdbarch.sh: Add generation of
"iterate_over_objfiles_in_search_order_cb_ftype" typedef in
gdbarch.h. Add include of "objfiles.h" in gdbarch.c.
(iterate_over_objfiles_in_search_order): New gdbarch method.
* gdbarch.h, gdbarch.c: Regenerate.
* objfiles.h (default_iterate_over_objfiles_in_search_order):
Add declaration.
* objfiles.c (default_iterate_over_objfiles_in_search_order):
New function.
* symtab.c (lookup_symbol_aux_objfile): New function, extracted
out of lookup_symbol_aux_symtabs.
(lookup_symbol_aux_symtabs): Replace extracted-out code by
call to lookup_symbol_aux_objfile.
(struct global_sym_lookup_data): New type.
(lookup_symbol_global_iterator_cb): New function.
(lookup_symbol_global): Search for symbol using
gdbarch_iterate_over_objfiles_in_search_order and
lookup_symbol_global_iterator_cb.
* findvar.c (struct minsym_lookup_data): New type.
(minsym_lookup_iterator_cb): New function.
(default_read_var_value) [case LOC_UNRESOLVED]: Resolve the
symbol's address via gdbarch_iterate_over_objfiles_in_search_order
and minsym_lookup_iterator_cb.
The search order used in this patch breaks global symbol lookups
for certain symbols when copy-relocation is used. A slightly different
search order will be implemented later.
gdb/ChangeLog:
Revert the following patch:
* findvar.c (default_read_var_value): For LOC_UNRESOLVED symbols,
try locating the symbol in the symbol's own objfile first, before
extending the search to all objfiles.
* symtab.c (lookup_symbol_aux_objfile): New function, extracted
out of lookup_symbol_aux_symtabs.
(lookup_symbol_aux_symtabs): Add new parameter "exclude_objfile".
Replace extracted-out code by call to lookup_symbol_aux_objfile.
Do not search EXCLUDE_OBJFILE.
(lookup_static_symbol_aux): Update call to lookup_symbol_aux_symtabs.
(lookup_symbol_global): Search for matches in the block's objfile
first, before searching all other objfiles.
gdb/ChangeLog:
* findvar.c (default_read_var_value): For LOC_UNRESOLVED symbols,
try locating the symbol in the symbol's own objfile first, before
extending the search to all objfiles.
* symtab.c (lookup_symbol_aux_objfile): New function, extracted
out of lookup_symbol_aux_symtabs.
(lookup_symbol_aux_symtabs): Add new parameter "exclude_objfile".
Replace extracted-out code by call to lookup_symbol_aux_objfile.
Do not search EXCLUDE_OBJFILE.
(lookup_static_symbol_aux): Update call to lookup_symbol_aux_symtabs.
(lookup_symbol_global): Search for matches in the block's objfile
first, before searching all other objfiles.
The purpose of this patch is to better support renamings in the
"info locals" command. Consider ...
procedure Foo is
GV : Integer renames Pck.Global_Variable;
begin
Increment (GV); -- STOP
end Foo;
... Pck.Global_Variable is just an integer. After having stopped at
the "STOP" line, "info locals" yields:
(gdb) info locals
gv = <error reading variable gv (Cannot access memory at address 0xffffffffffffffff)>
In reality, two things are happening:
(1) Variable "GV" does not exist, which is normal, since there is
"GV" the renaming of another variable;
(2) But to allow the user access to that renaming the same way
the code has, the compiler produces an artificial variable
whose name encodes the renaming:
gv___XR_pck__global_variable___XE
For practical reasons, the artificial variable itself is given
irrelevant types and addresses.
But the "info locals" command does not act as if it was a short-cut
of "foreach VAR in locals, print VAR". Instead it gets the value of
each VAR directly, which does not work in this case, since the variable
is artificial and needs to be decoded first.
This patch makes the "read_var_value" routine language-specific.
The old implementation of "read_var_value" gets renamed to
"default_read_var_value" and all languages now use it (unchanged
behavior), except for Ada. In Ada, the new function ada_read_var_value
checks if we have a renaming, and if so, evaluates its value, or else
defers to default_read_var_value.
gdb/ChangeLog:
* language.h (struct language_defn): New "method" la_read_var_value.
* findvar.c: #include "language.h".
(default_read_var_value): Renames read_var_value. Rewrite
function description.
(read_var_value): New function.
* value.h (default_read_var_value): Add prototype.
* ada-lang.c (ada_read_renaming_var_value, ada_read_var_value):
New functions.
(ada_language_defn): Add entry for la_read_var_value.
* c-lang.c, d-lang.c, f-lang.c, jv-lang.c, language.c,
* m2-lang.c, objc-lang.c, opencl-lang.c, p-lang.c: Update
language_defn structures to add entry for new la_read_var_value
field.
The read_frame_register_value function as it was implemented introduced
a regression on big-endian targets. The problem appears when trying to
get the value of an entity stored inside a register, and when the size
of the entity is smaller than the size of the register. In that case,
we were always reading the first N bytes of the register, which is wrong
for big-endian architectures, where we need to read the last N bytes of
the register.
gdb/ChangeLog:
* findvar.c (read_frame_register_value): Read correct bytes from
register on big-endian architectures.
gdb/testsuite/ChangeLog:
* gdb.ada/small_reg_param: New testcase.
gdb/ChangeLog:
* value.h (read_frame_register_value): Add declaration.
* findvar.c (read_frame_register_value): New function.
(value_from_register): Use read_frame_register_value
instead of get_frame_register_value + value_contents_copy
to get value contents.
* findvar.c (read_var_value): Never return NULL, throw an error
instead. Update the function comment. State symbol name in the error
messages.
* python/py-frame.c (frapy_read_var): Remove handling of NULL from
read_var_value.
* stack.c (print_frame_args): Likewise.
* valops.c (value_of_variable): Likewise.
Code cleanup making also optimized out values lazy.
* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Use
allocate_optimized_out_value. Twice.
(loclist_read_variable) Use allocate_optimized_out_value. Once.
* findvar.c (read_var_value): Likewise.
* value.c (allocate_optimized_out_value): New function.
* value.h (allocate_optimized_out_value): New declaration.
* dwarf2loc.c (read_pieced_value): Handle get_frame_register_bytes
returning that the register piece is unavailable/optimized out.
(write_pieced_value): Handle get_frame_register_bytes returning
that the register piece is unavailable/optimized out when doing a
read-modify write of a bitfield.
* findvar.c (value_from_register): Handle get_frame_register_bytes
returning that the register piece is unavailable/optimized out.
* frame.c (get_frame_register_bytes): New parameters `optimizedp'
and `unavailablep'. Throw error on bad debug info. Use
frame_register instead of frame_register_read, to fill in the new
arguments.
* frame.h (get_frame_register_bytes): New parameters `optimizedp'
and `unavailablep'.
* valops.c: (value_assign): Adjust, and handle
get_frame_register_bytes failing.
* spu-tdep.c: Include exceptions.h.
(spu_software_single_step): Adjust, and handle
get_frame_register_bytes failing.
(spu_get_longjmp_target): Ditto.
* gdbarch.sh (register_to_value): Change to return int. New
parameters `optimizedp' and `unavailablep'.
* gdbarch.h, gdbarch.c: Regenerate.
* i386-tdep.c (i386_register_to_value): Adjust to new
gdbarch_register_to_value interface.
* i387-tdep.c (i387_register_to_value): Ditto.
* i387-tdep.h (i387_register_to_value): Ditto.
* alpha-tdep.c (alpha_register_to_value): Ditto.
* ia64-tdep.c (ia64_register_to_value): Ditto.
* m68k-tdep.c (m68k_register_to_value): Ditto.
* mips-tdep.c (mips_register_to_value): Ditto.
* rs6000-tdep.c (rs6000_register_to_value): Ditto.
* findvar.c (value_of_register): Mark the value as unavailable, if
the register is unavailable.
* frame.h (frame_register_unwind): New `unavailablep' parameter.
(frame_register): New `unavailablep' parameter.
(frame_register_read): Update comment.
* frame.c (frame_register_unwind): New `unavailablep' parameter.
Set it if the register is unavailable. If the register is
unavailable, clear the output buffer.
(frame_register): New `unavailablep' parameter. Pass it down.
(frame_unwind_register): Adjust.
(put_frame_register): Adjust.
(frame_register_read): Adjust. Also return false if the register
is not available.
(frame_register_unwind_location): Adjust.
* sentinel-frame.c (sentinel_frame_prev_register): If the register
is unavailable, mark the value accordingly.
* stack.c (frame_info): Handle unavailable registers.
gdb/testsuite/
* gdb.trace/unavailable.exp (fpreg, spreg, pcreg): Define.
(test_register, test_register_unavailable): New procedures.
(gdb_unavailable_registers_test): New procedure.
(gdb_trace_collection_test): Call it.
Make value allocations more lazy.
* ada-lang.c (coerce_unspec_val_to_type): Use allocate_value_lazy
instead of allocate_value and set_value_lazy when possible.
* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Use allocate_value_lazy
instead of allocate_value and set_value_lazy.
* findvar.c (value_of_register_lazy): Likewise.
(read_var_value): Remove V preallocation, call just check_typedef in
advance. Move allocate_value to LOC_CONST, LOC_LABEL,
LOC_CONST_BYTES. Use allocate_value_lazy in LOC_STATIC, LOC_ARG,
LOC_REF_ARG, LOC_LOCAL, LOC_BLOCK. Set ADDR instead of
set_value_address and break in LOC_BLOCK. Use allocate_value_lazy and
remove lval_memory set in LOC_REGPARM_ADDR. Use allocate_value_lazy
in LOC_UNRESOLVED and LOC_OPTIMIZED_OUT. Add setting lval_memory at
the end, remove set_value_lazy there.
* valarith.c (value_subscripted_rvalue): Use allocate_value_lazy
instead of allocate_value and set_value_lazy when possible.
* valops.c (value_fetch_lazy): Do nop for value_optimized_out VAL.
* value.c (allocate_computed_value): Use allocate_value_lazy instead
of allocate_value and set_value_lazy.
(value_from_contents_and_address): Use allocate_value_lazy instead of
allocate_value and set_value_lazy when possible.
* findcmd.c: White space.
* findvar.c: White space.
* fork-child.c: White space.
* frame-base.c: White space.
* frame.c: White space.
* frame-unwind.c: White space.
* f-valprint.c: White space.
smash_to_memberptr_type, lookup_array_range_type, check_stub_method):
Use type architecture instead of current_gdbarch.
* gdbtypes.h (address_space_name_to_int, address_space_int_to_name):
Add GDBARCH paramter.
* gdbtypes.c (address_space_name_to_int, address_space_int_to_name):
Add GDBARCH parameter. Use it instead of current_gdbarch.
* c-typeprint.c (c_type_print_modifier): Update call.
* parse.c (push_type_address_space): Likewise.
* findvar.c (extract_typed_address, store_typed_address): Use type
architecture instead of current_gdbarch.
* value.c (value_as_address, unpack_field_as_long): Use type architecture
instead of current_gdbarch.
* doublest.c (floatformat_from_length): Add GDBARCH argument. Use it
instead of current_gdbarch.
(floatformat_from_type): Pass type architecture.
* infcall.c (find_function_addr): Use type architecture instead
of current_gdbarch.
* valarith.c (value_bitstring_subscript, value_x_binop, value_neg,
value_bit_index): Use type architecture instead of current_gdbarch.
* valops.c (value_cast, value_slice): Likewise.
* value.h (modify_field): Add TYPE argument.
* value.c (modify_field): Add TYPE argument. Use type architecture
instead of current_gdbarch.
(set_internalvar_component): Likewise.
* eval.c (evaluate_struct_tuple): Update call.
* valops.c (value_assign): Likewise.
* ada-lang.c (modify_general_field): Likewise. Add TYPE argument.
(make_array_descriptor): Update calls.
(move_bits): Add BITS_BIG_ENDIAN_P argument. Use it instead of
current_gdbarch.
(ada_value_assign, value_assign_to_component): Update calls.
(decode_packed_array, ada_value_primitive_packed_val, ada_value_assign,
value_assign_to_component): Use type arch instead of current_gdbarch.
* printcmd.c (float_type_from_length): Remove GDBARCH argument,
use type architecture instead.
(print_scalar_formatted, printf_command): Update calls. Use type
architecture instead of current_gdbarch.
* valprint.c (val_print_type_code_int): Use type architecture
instead of current_gdbarch.
* varobj.c (value_get_print_value): Likewise.
* python/python-prettyprint.c (print_string_repr): Add GDBARCH
argument. Use it instead of current_gdbarch.
(apply_val_pretty_printer): Update call.
* ada-valprint.c (ada_val_print_1): Use type architecture instead
of current_gdbarch.
* c-valprint.c (print_function_pointer_address): Add GDBARCH argument.
Use it instead of current_gdbarch.
(c_val_print): Update calls passing type architecture.
* f-valprint.c (f_val_print): Use type architecture instead of
current_gdbarch.
* jv-valprint (java_value_print): Likewise.
* m2-valprint.c (print_function_pointer_address): Add GDBARCH argument.
Use it instead of current_gdbarch.
(print_unpacked_pointer): Update calls passing type architecture.
* scm-valprint.c (scm_scmval_print): Use type architecture instead of
current_gdbarch.
* gnu-v3-abi.c (get_class_arch): Remove.
(gnuv3_rtti_type): Use get_type_arch instead of get_class_arch. Remove
special-case check for Java classes.
(gnuv3_virtual_fn_field, gnuv3_baseclass_offset, gnuv3_print_method_ptr,
gnuv3_method_ptr_size, gnuv3_make_method_ptr, gnuv3_method_ptr_to_value):
Use get_type_arch instead of get_class_arch.
(locate_var_value): Remove prototype.
* findvar.c (read_var_value): Do not attempt to default frame
to selected frame.
(locate_var_value): Remove function.
* valops.c (value_of_variable): Retrieve selected frame for
symbols that require a frame when called with NULL block.
* valops.c (address_of_variable): New function.
* eval.c (evaluate_subexp_for_address): Call address_of_variable
instead of calling locate_var_value.
(evaluate_subexp_with_coercion): Likewise.
* blockframe.c (find_pc_partial_function): Likewise.
* buildsym.c (find_symbol_in_list): Likewise.
* c-valprint.c (c_val_print): Likewise.
* coffread.c (patch_opaque_types, process_coff_symbol): Likewise.
(coff_read_enum_type): Likewise. Use SYMBOL_SET_LINKAGE_NAME.
* cp-support.c (cp_remove_params): Renamed from remove_params and
made global.
(overload_list_add_symbol): Update call to remove_params.
* cp-support.h (cp_remove_params): Declare.
* dwarf2read.c (process_enumeration_scope): Use SYMBOL_LINKAGE_NAME.
(dwarf2_const_value): Use SYMBOL_PRINT_NAME.
* expprint.c (dump_subexp_body_standard): Likewise.
* f-valprint.c (info_common_command, there_is_a_visible_common_named):
Use SYMBOL_LINKAGE_NAME to find symbols and SYMBOL_PRINT_NAME
for messages.
* findvar.c (read_var_value): Use SYMBOL_LINKAGE_NAME.
* gnu-v2-abi.c (gnuv2_value_rtti_type): Likewise.
* hppa-hpux-tdep.c (hppa32_hpux_in_solib_call_trampoline)
(hppa_hpux_skip_trampoline_code): Use SYMBOL_LINKAGE_NAME to find
symbols and SYMBOL_PRINT_NAME for messages.
* jv-lang.c (add_class_symbol): Use SYMBOL_SET_LINKAGE_NAME.
* linespec.c (decode_line_2): Use SYMBOL_LINKAGE_NAME.
* mdebugread.c (parse_symbol): Use SYMBOL_LINKAGE_NAME and
SYMBOL_SET_LINKAGE_NAME.
(mylookup_symbol): Use SYMBOL_LINKAGE_NAME.
* minsyms.c (add_minsym_to_demangled_hash_table): Use
SYMBOL_SEARCH_NAME.
(lookup_minimal_symbol): Use SYMBOL_LINKAGE_NAME or
SYMBOL_MATCHES_SEARCH_NAME, depending on the pass.
* objfiles.h (ALL_OBJFILE_MSYMBOLS): Use SYMBOL_LINKAGE_NAME.
* printcmd.c (build_address_symbolic): Use SYMBOL_LINKAGE_NAME.
(address_info): Use SYMBOL_PRINT_NAME for messages and
SYMBOL_LINKAGE_NAME for lookups.
* sol-thread.c (info_cb): Use SYMBOL_PRINT_NAME for messages.
* stabsread.c (patch_block_stabs, define_symbol)
(read_type, read_enum_type, common_block_end)
(cleanup_undefined_types_1, scan_file_globals): Use
SYMBOL_LINKAGE_NAME, SYMBOL_SET_LINKAGE_NAME, ALL_OBJFILE_MSYMBOLS,
and SYMBOL_PRINT_NAME.
* stack.c (print_frame_args): Use SYMBOL_LINKAGE_NAME.
(print_frame, frame_info): Use SYMBOL_PRINT_NAME for output. Use
cp_remove_params instead of cplus_demangle.
(print_block_frame_labels, print_frame_arg_vars): Use
SYMBOL_LINKAGE_NAME.
* symmisc.c (dump_msymbols): Use ALL_OBJFILE_MSYMBOLS and
SYMBOL_LINKAGE_NAME.
(dump_symtab_1, print_symbol, print_partial_symbols)
(maintenance_check_symtabs): Use SYMBOL_LINKAGE_NAME.
* symtab.h (DEPRECATED_SYMBOL_NAME): Delete.
(SYMBOL_SET_LINKAGE_NAME): New.
(SYMBOL_SET_NAMES): Add a comment.
* tracepoint.c (set_traceframe_context, validate_actionline)
(collect_symbol, scope_info): Use SYMBOL_LINKAGE_NAME for
lookups and SYMBOL_PRINT_NAME for output.
* typeprint.c (typedef_print): Use SYMBOL_LINKAGE_NAME.
* xcoffread.c (process_xcoff_symbol): Use SYMBOL_SET_LINKAGE_NAME.
* findvar.c (value_of_register, locate_var_value): Use
get_regcache_arch or get_frame_arch to get at the current architecture
by regcache or by frame, respectively.
* findvar.c (default_value_from_register, value_from_register): Replace
current_gdbarch by gdbarch.
