PR binutils/20876
bfd * opncls.c (find_separate_debug_file): Add include_dirs
parameter. Only include the directory part of the bfd's filename
in search paths if include_dirs is true. Add a couple of extra
locations for looking for debug files.
( bfd_follow_gnu_debuglink): Update invocation of
find_separate_debug_file.
(bfd_follow_gnu_debugaltlink): Likewise.
(get_build_id): New function: Finds the build-id of the given bfd.
(get_build_id_name): New function: Computes the name of the
separate debug info file for a bfd, based upon its build-id.
(check_build_id_file): New function: Checks to see if a separate
debug info file exists at the given location, and that its
build-id matches that of the original bfd.
(bfd_follow_build_id_debuglink): New function: Finds a separate
debug info file for a given bfd by using the build-id method.
* dwarf2.c (_bfd_dwarf2_slurp_debug_info): Try using the build-id
method of locating a separate debug info file before using the
debuglink method.
* bfd-in2.h: Regenerate.
binutils * NEWS: Mention the new feature.
* testsuite/binutils-all/objdump.exp (test_build_id_debuglink):
New proc to test the location of separate debug info files using
the build-id method.
I find this comment counter intuitive, and it probably predates the
always-target-async change. AFAIK, remote will always be async, unless
the user explicitly prevents it with "maint set target-async off".
gdb/ChangeLog:
* remote.c (remote_can_async_p): Update comment.
I think this comment is outdated. Nowadays, linux-nat is always async,
unless the user has explictly turned it off with
"maint set target-async off".
gdb/ChangeLog:
* linux-nat.c (linux_nat_can_async_p): Update comment.
By inspecting the serial_add_interface calls, I found that the serial
interface names that we have today are:
- hardwire
- terminal
- pipe
- tcp
- event
The calls to serial_interface_lookup with any other names are most
likely leftovers which can be removed since these serial interfaces
don't exist anymore. The commits that removed the "pc" and "parallel"
interfaces are respectively:
cb2a4ac5da
and
e386d4d2fb
gdb/ChangeLog:
* serial.c (serial_open): Forget about "pc" and "lpt" serial interface.
* read.c (temp_ilp): New function. Installs a temporary input
line pointer.
(restore_ilp): New function. Restores the original input line
pointer.
* read.h (temp_ilp): Prototype.
(restore_ilp): Prototype.
* stabs.c (dot_func_p): Use bfd_boolean type.
(generate_asm_file): Use temp_ilp and restore_ilp.
(stabs_generate_asm_lineno): Likewise.
(stabs_generate_asm_endfunc): Likewise.
Disassemblers in opcodes return -1 on memory error, but msp430 doesn't
follow this convention. If I change GDB not to throw exception in
disassemble_info.memory_error_func and rely on the return value of
disassembler, I'll get the following output.
(gdb) disassemble 0x0,+8
Dump of assembler code from 0x0 to 0x8:
0x00000000: .word 0xffff; ????
0x00000002: .word 0xffff; ????
0x00000004: .word 0xffff; ????
0x00000006: .word 0xffff; ????
End of assembler dump.
This patch teaches print_insn_msp430 and its callees to return -1
on memory error.
opcodes:
2017-01-12 Yao Qi <yao.qi@linaro.org>
* msp430-dis.c (msp430_singleoperand): Return -1 if
msp430dis_opcode_signed returns false.
(msp430_doubleoperand): Likewise.
(msp430_branchinstr): Return -1 if
msp430dis_opcode_unsigned returns false.
(msp430x_calla_instr): Likewise.
(print_insn_msp430): Likewise.
bfd * config.bfd: Add entries for i686-redox and x86_64-redox.
gas * configure.tgt: Add entry for i386-redox.
ld * configure.tgt: Add entries for x86-redox and x86_64-redox.
This adds a constructor and destructor to demangle_parse_info, and
then changes all the users to use them. This removes
make_cleanup_cp_demangled_name_parse_free and its single use.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-type.c (typy_legacy_template_argument): Update.
* cp-support.h (struct demangle_parse_info) (demangle_parse_info,
~demangle_parse_info): Declare new members.
(cp_demangled_name_to_comp): Return unique_ptr.
(cp_demangled_name_parse_free)
(make_cleanup_cp_demangled_name_parse_free)
(cp_new_demangle_parse_info): Remove.
* cp-support.c (do_demangled_name_parse_free_cleanup)
(make_cleanup_cp_demangled_name_parse_free): Remove.
(inspect_type, cp_canonicalize_string_full)
(cp_canonicalize_string): Update.
(mangled_name_to_comp): Change return type.
(cp_class_name_from_physname, method_name_from_physname)
(cp_func_name, cp_remove_params): Update.
* cp-name-parser.y (demangle_parse_info): New constructor, from
cp_new_demangle_parse_info.
(~demangle_parse_info): New destructor, from
cp_demangled_name_parse_free.
(cp_merge_demangle_parse_infos): Update.
(cp_demangled_name_to_comp): Change return type.
This replaces a cleanup in execute_gdb_command with an instance of
std::string.
Testing showed that this originally missed a cleanup that was returned
by prevent_dont_repeat. This version of the patch changes
prevent_dont_repeat to return a scoped_restore rather than a cleanup.
2017-01-10 Tom Tromey <tom@tromey.com>
* top.c (prevent_dont_repeat): Change return type.
* python/python.c (execute_gdb_command): Use std::string.
Update.
* guile/guile.c (gdbscm_execute_gdb_command): Update.
* command.h (prevent_dont_repeat): Change return type.
* breakpoint.c (bpstat_do_actions_1): Update.
This changes dwarf2_evaluate_loc_desc_full to use scoped_value_mark.
Note that this function previously called do_cleanup using the same
cleanup multiple times. I had thought this was buggy, but re-reading
make_my_cleanup2 indicates that it is not. Nevertheless it is
surprising, and at least one of the calls (the one that is completely
removed in this patch) seems to have been done under the assumption
that it would still have some effect.
2017-01-10 Tom Tromey <tom@tromey.com>
* value.h (scoped_value_mark::~scoped_value_mark): Call
free_to_mark.
(scoped_value_mark::free_to_mark): New method.
* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Use
scoped_value_mark.
This adds a scoped_value_mark class, that records the value mark in
the constructor and then calls value_free_to_mark in the destructor.
It then updates various spots in gdb to use this class, rather than a
cleanup.
It would be better overall to replace "struct value *" with a
shared_ptr, maybe eliminating the need for this class (watchpoints
would perhaps need some new mechanism as well). However, that's
difficult to do.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-value.c (valpy_dereference, valpy_referenced_value)
(valpy_reference_value, valpy_const_value, valpy_get_address)
(valpy_get_dynamic_type, valpy_lazy_string, valpy_do_cast)
(valpy_getitem, valpy_call, valpy_binop_throw, valpy_negative)
(valpy_absolute, valpy_richcompare_throw): Use scoped_value_mark.
* dwarf2loc.c (dwarf2_loc_desc_get_symbol_read_needs): Use
scoped_value_mark.
* dwarf2-frame.c (execute_stack_op): Use scoped_value_mark.
* value.h (scoped_value_mark): New class.
This removes make_cleanup_discard_psymtabs in favor of a new class.
2017-01-10 Tom Tromey <tom@tromey.com>
* dwarf2read.c (dwarf2_build_psymtabs): Use psymtab_discarder.
* psympriv.h (make_cleanup_discard_psymtabs): Don't declare.
* psymtab.c (discard_psymtabs_upto): Remove.
(make_cleanup_discard_psymtabs): Remove.
(struct psymtab_state): Remove.
This introduces a new class, gdb::unlinker, that unlinks a file in the
destructor. The user of this class has the option to preserve the
file instead, by calling the "keep" method.
This patch then changes the spots in gdb that use unlink in a cleanup
to use this class instead. In one spot I went ahead and removed all
the cleanups from the function.
This fixes one latent bug -- do_bfd_delete_cleanup could refer to
freed memory, by decref'ing the BFD before using its filename.
2017-01-10 Tom Tromey <tom@tromey.com>
* record-full.c (record_full_save_cleanups): Remove.
(record_full_save): Use gdb::unlinker.
* gcore.c (do_bfd_delete_cleanup): Remove.
(gcore_command): Use gdb::unlinker, unique_xmalloc_ptr. Remove
cleanups.
* dwarf2read.c (unlink_if_set): Remove.
(write_psymtabs_to_index): Use gdb::unlinker.
* common/gdb_unlinker.h: New file.
This introduces a new specialization of gdb::ref_ptr that can be used
to manage BFD reference counts. Then it changes most places in gdb to
use this new class, rather than explicit reference-counting or
cleanups. This patch removes make_cleanup_bfd_unref.
If you look you will see a couple of spots using "release" where a use
of gdb_bfd_ref_ptr would be cleaner. These will be fixed in the next
patch.
I think this patch fixes some latent bugs. For example, it seems to
me that previously objfpy_add_separate_debug_file leaked a BFD.
I'm not 100% certain that the macho_symfile_read_all_oso change is
correct. The existing code here is hard for me to follow. One goal
of this sort of automated reference counting, though, is to make it
more difficult to make logic errors; so hopefully the code is clear
now.
2017-01-10 Tom Tromey <tom@tromey.com>
* windows-tdep.c (windows_xfer_shared_library): Update.
* windows-nat.c (windows_make_so): Update.
* utils.h (make_cleanup_bfd_unref): Remove.
* utils.c (do_bfd_close_cleanup, make_cleanup_bfd_unref): Remove.
* symfile.h (symfile_bfd_open)
(find_separate_debug_file_in_section): Return gdb_bfd_ref_ptr.
* symfile.c (read_symbols, symbol_file_add)
(separate_debug_file_exists): Update.
(symfile_bfd_open): Return gdb_bfd_ref_ptr.
(generic_load, reread_symbols): Update.
* symfile-mem.c (symbol_file_add_from_memory): Update.
* spu-linux-nat.c (spu_bfd_open): Return gdb_bfd_ref_ptr.
(spu_symbol_file_add_from_memory): Update.
* solist.h (struct target_so_ops) <bfd_open>: Return
gdb_bfd_ref_ptr.
(solib_bfd_fopen, solib_bfd_open): Return gdb_bfd_ref_ptr.
* solib.c (solib_bfd_fopen, solib_bfd_open): Return
gdb_bfd_ref_ptr.
(solib_map_sections, reload_shared_libraries_1): Update.
* solib-svr4.c (enable_break): Update.
* solib-spu.c (spu_bfd_fopen): Return gdb_bfd_ref_ptr.
* solib-frv.c (enable_break2): Update.
* solib-dsbt.c (enable_break): Update.
* solib-darwin.c (gdb_bfd_mach_o_fat_extract): Return
gdb_bfd_ref_ptr.
(darwin_solib_get_all_image_info_addr_at_init): Update.
(darwin_bfd_open): Return gdb_bfd_ref_ptr.
* solib-aix.c (solib_aix_bfd_open): Return gdb_bfd_ref_ptr.
* record-full.c (record_full_save): Update.
* python/py-objfile.c (objfpy_add_separate_debug_file): Update.
* procfs.c (insert_dbx_link_bpt_in_file): Update.
* minidebug.c (find_separate_debug_file_in_section): Return
gdb_bfd_ref_ptr.
* machoread.c (macho_add_oso_symfile): Change abfd to
gdb_bfd_ref_ptr.
(macho_symfile_read_all_oso): Update.
(macho_check_dsym): Return gdb_bfd_ref_ptr.
(macho_symfile_read): Update.
* jit.c (bfd_open_from_target_memory): Return gdb_bfd_ref_ptr.
(jit_bfd_try_read_symtab): Update.
* gdb_bfd.h (gdb_bfd_open, gdb_bfd_fopen, gdb_bfd_openr)
(gdb_bfd_openw, gdb_bfd_openr_iovec)
(gdb_bfd_openr_next_archived_file, gdb_bfd_fdopenr): Return
gdb_bfd_ref_ptr.
(gdb_bfd_ref_policy): New struct.
(gdb_bfd_ref_ptr): New typedef.
* gdb_bfd.c (gdb_bfd_open, gdb_bfd_fopen, gdb_bfd_openr)
(gdb_bfd_openw, gdb_bfd_openr_iovec)
(gdb_bfd_openr_next_archived_file, gdb_bfd_fdopenr): Return
gdb_bfd_ref_ptr.
* gcore.h (create_gcore_bfd): Return gdb_bfd_ref_ptr.
* gcore.c (create_gcore_bfd): Return gdb_bfd_ref_ptr.
(gcore_command): Update.
* exec.c (exec_file_attach): Update.
* elfread.c (elf_symfile_read): Update.
* dwarf2read.c (dwarf2_get_dwz_file): Update.
(try_open_dwop_file, open_dwo_file): Return gdb_bfd_ref_ptr.
(open_and_init_dwo_file): Update.
(open_dwp_file): Return gdb_bfd_ref_ptr.
(open_and_init_dwp_file): Update.
* corelow.c (core_open): Update.
* compile/compile-object-load.c (compile_object_load): Update.
* common/gdb_ref_ptr.h (ref_ptr::operator->): New operator.
* coffread.c (coff_symfile_read): Update.
* cli/cli-dump.c (bfd_openr_or_error, bfd_openw_or_error): Return
gdb_bfd_ref_ptr. Rename.
(dump_bfd_file, restore_command): Update.
* build-id.h (build_id_to_debug_bfd): Return gdb_bfd_ref_ptr.
* build-id.c (build_id_to_debug_bfd): Return gdb_bfd_ref_ptr.
(find_separate_debug_file_by_buildid): Update.
This adds a new gdb_ref_ptr.h, that implements a reference-counting
smart pointer class, where the user of the class supplies a
reference-counting policy object.
This class will be used in the next patch, which changes most explicit
BFD reference counts to use this new type. Meanwhile, this patch
changes gdbpy_ref to be a specialization of this new class.
This change required adding new nullptr_t overloads some operators in
gdb_ref_ptr.h. I suspect this was needed because some Python header
redefines NULL, but I'm not certain.
2017-01-10 Tom Tromey <tom@tromey.com>
* common/gdb_ref_ptr.h: New file.
* python/py-ref.h (struct gdbpy_ref_policy): New.
(gdbpy_ref): Now a typedef.
This removes make_cleanup_htab_delete in favor of destructors,
building on an earlier patch that added the htab_up typedef.
Testing revealed that more cleanup-removal work was needed in
dwarf2loc.c, so this version of the patch changes code there to use
unordered_set and vector, removing some more cleanups.
2017-01-10 Tom Tromey <tom@tromey.com>
* utils.h (make_cleanup_htab_delete): Don't declare.
* utils.c (do_htab_delete_cleanup, make_cleanup_htab_delete):
Remove.
* linespec.c (decode_compound_collector): Add constructor,
destructor.
(lookup_prefix_sym): Remove cleanup.
(symtab_collector): Add constructor, destructor.
(collect_symtabs_from_filename): Remove cleanup.
* disasm.c (do_mixed_source_and_assembly): Use htab_up.
* compile/compile-c-symbols.c (generate_c_for_variable_locations):
Use htab_up.
* gnu-v3-abi.c (gnuv3_print_vtable): Use htab_up.
* dwarf2read.c (dw2_expand_symtabs_matching)
(dw2_map_symbol_filenames, dwarf_decode_macros)
(write_psymtabs_to_index): Use htab_up.
* dwarf2loc.c (func_verify_no_selftailcall)
(call_site_find_chain_1, func_verify_no_selftailcall)
(chain_candidate, call_site_find_chain_1): Use std::unordered_set,
std::vector, gdb::unique_xmalloc_ptr.
(call_sitep): Remove typedef.
(dwarf2_locexpr_baton_eval): Remove unused variable.
make_cleanup_py_decref and make_cleanup_py_xdecref are now unused, so
this patch removes themm. Future Python changes should use gdbpy_ref
instead.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/python-internal.h (make_cleanup_py_decref)
(make_cleanup_py_xdecref): Don't declare.
* python/py-utils.c (py_decref, make_cleanup_py_decref)
(py_xdecref, make_cleanup_py_xdecref): Remove.
This changes some spots in py-framefilter.c to use gdbpy_ref rather
than make_cleanup_py_decref or make_cleanup_py_xdecref.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-framefilter.c (py_mi_print_variables): Use gdbpy_ref.
(py_print_locals, enumerate_locals, py_print_args): Use gdbpy_ref.
This changes enumerate_args to use gdbpy_ref, and gets rid of many
gotos.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-framefilter.c (enumerate_args): Use gdbpy_ref.
This changes more places in py-utils.c to use gdbpy_ref.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-utils.c (unicode_to_encoded_string)
(python_string_to_target_string)
(python_string_to_target_python_string)
(python_string_to_host_string, gdbpy_obj_to_string)
(get_addr_from_python): Use gdbpy_ref.
This changes pyuw_object_attribute_to_pointer to use gdbpy_ref.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-unwind.c (pyuw_object_attribute_to_pointer): Use
gdbpy_ref.
This changes more places in python.c to use gdbpy_ref.
Additionally, previously gdbpy_apply_type_printers would return
EXT_LANG_RC_ERROR if a type printer returned None. However, that
doesn't seem correct to me; this patch changes it to return
EXT_LANG_RC_NOP in this case.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/python.c (eval_python_command, gdbpy_decode_line)
(gdbpy_run_events, gdbpy_start_type_printers)
(gdbpy_apply_type_printers): Use gdbpy_ref.
This changes py-param.c to use gdbpy_ref in a couple more spots.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-param.c (get_doc_string, compute_enum_values): Use
gdbpy_ref.
This changes py-inferior.c to use gdbpy_ref in more places.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-inferior.c (find_thread_object, build_inferior_list):
Use gdbpy_ref.
This changes py_print_frame to use gdbpy_ref in more places.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-framefilter.c (py_print_frame): Use gdbpy_ref.
This changes bpfinishpy_out_of_scope to use gdbpy_ref.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-finishbreakpoint.c (bpfinishpy_out_of_scope): Use
gdbpy_ref.
This changes py-cmd.c to use gdbpy_ref in more places. This also
fixes a latent memory leak in cmdpy_completer_helper, which
unnecessarily increfs the result of PyObject_CallMethodObjArgs. This
is not needed because that function returns a new reference.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-cmd.c (cmdpy_completer_helper): Use gdbpy_ref. Remove
extra incref.
(cmdpy_completer_handle_brkchars, cmdpy_completer, cmdpy_init):
Use gdbpy_ref.
This changes gdbpy_breakpoint_cond_says_stop to use gdbpy_ref rather
than explicit reference management.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-breakpoint.c (gdbpy_breakpoint_cond_says_stop): Use
gdbpy_ref.
This changes archpy_disassemble to use gdbpy_ref. It also fixes a
latent bug where archpy_disassemble was decref'ing the results of a
all to PyArg_ParseTupleAndKeywords. This is incorrect because
PyArg_ParseTupleAndKeywords returns borrowed references.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-arch.c (archpy_disassemble): Use gdbpy_ref. Don't
decref results of PyArg_ParseTupleAndKeywords.
This changes python_run_simple_file to use gdbpy_ref and
unique_xmalloc_ptr. Thi fixes a latent bug in this function, where
the error path previously ran the cleanups and then referred to one of
the objects just freed.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/python.c (python_run_simple_file): Use
unique_xmalloc_ptr, gdbpy_ref.
This changes some spots in py-prettyprint.c to use gdbpy_ref. It also
changes push_dummy_python_frame to be a class, rather than having it
create a cleanup.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-prettyprint.c (print_stack_unless_memory_error)
(print_string_repr, print_children): Use gdbpy_ref.
(dummy_python_frame): New class.
(dummy_python_frame::dummy_python_frame): Rename from
push_dummy_python_frame.
(py_restore_tstate): Remove.
This changes py_print_frame to use gdbpy_ref in a few spots.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-framefilter.c (py_print_frame): Use gdbpy_ref.
All of gdb has been converted away from ensure_python_env and
varobj_ensure_python_env now; so remove them.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/python.c (ensure_python_env, restore_python_env):
Remove.
* python/python-internal.h (ensure_python_env): Don't declare.
* varobj.h (varobj_ensure_python_env): Don't declare.
* varobj.c (varobj_ensure_python_env): Remove.
This changes the last function in varobj.c to use gdbpy_enter_varobj.
2017-01-10 Tom Tromey <tom@tromey.com>
* varobj.c (varobj_value_get_print_value): Use
gdbpy_enter_varobj.
This changes gdbpy_extract_lazy_string's "encoding" argument to be a
unique_xmalloc_ptr. I chose this rather than std::string because it
can sometimes be NULL.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-prettyprint.c (print_string_repr, print_children):
Update.
* python/py-lazy-string.c (gdbpy_extract_lazy_string): Change type
of "encoding".
* varobj.c (varobj_value_get_print_value): Update.
* python/python-internal.h (gdbpy_extract_lazy_string): Update.
This converts most of the remaining functions in varobj.c to use
gdbpy_enter_varobj.
2017-01-10 Tom Tromey <tom@tromey.com>
* varobj.c (varobj_get_display_hint)
(dynamic_varobj_has_child_method, install_new_value_visualizer)
(varobj_set_visualizer, free_variable): Use
gdbpy_enter_varobj.
This changes the last functions in python.c to use gdbpy_enter. I
split gdbpy_finish_initialization into two functions in order to avoid
some "goto"s.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/python.c (python_command): Use gdbpy_enter, gdbpy_ref.
(do_finish_initialization): New function. Use gdbpy_ref.
(gdbpy_finish_initialization): Use gdbpy_enter. Call
do_finish_initialization.
This converts the remaining functions in py-param.c to use
gdbpy_enter.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-param.c (get_set_value, get_show_value): Use
gdbpy_enter, gdbpy_ref.
This changes fnpy_call to use gdbpy_enter and gdbpy_ref.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-function.c (fnpy_call): Use gdbpy_enter, gdbpy_ref.
This changes cmdpy_function to use gdbpy_enter and gdbpy_ref.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-cmd.c (cmdpy_function): Use gdbpy_enter, gdbpy_ref.
This converts the remaining functions in py-varobj.c to use
gdbpy_enter_varobj.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-varobj.c (py_varobj_iter_dtor, py_varobj_iter_next):
Use gdbpy_enter_varobj.
This introduces gdbpy_enter_varobj, a subclass of gdbpy_enter; then
changes one function in py-varobj.c to use it. gdbpy_enter_varobj
takes a varobj as an argument, similar to varobj_ensure_python_env.
2017-01-10 Tom Tromey <tom@tromey.com>
* varobj.c (gdbpy_enter_varobj): New constructor.
* python/python-internal.h (gdbpy_enter_varobj): New class.
* python/py-varobj.c (py_varobj_get_iterator): Use
gdbpy_enter_varobj.
This changes the remaining functions in py-xmethod.c to use
gdbpy_enter; using gdbpy_ref and unique_xmalloc_ptr as
appropriate.
2017-01-10 Tom Tromey <tom@tromey.com>
* python/py-xmethods.c (gdbpy_get_xmethod_result_type): Use
gdbpy_enter, gdbpy_ref, unique_xmalloc_ptr.
(gdbpy_invoke_xmethod): Use gdbpy_ref, gdbpy_enter.
(gdbpy_get_xmethod_arg_types): Use gdbpy_ref,
unique_xmalloc_ptr.
(gdbpy_get_xmethod_arg_types): Use gdbpy_ref, gdbpy_enter.