- Rationale:
It is possible for compilers to indicate the desired byte order
interpretation of scalar variables using the DWARF attribute:
DW_AT_endianity
A type flagged with this variable would typically use one of:
DW_END_big
DW_END_little
which instructs the debugger what the desired byte order interpretation
of the variable should be.
The GCC compiler (as of V6) has a mechanism for setting the desired byte
ordering of the fields within a structure or union. For, example, on a
little endian target, a structure declared as:
struct big {
int v;
short a[4];
} __attribute__( ( scalar_storage_order( "big-endian" ) ) );
could be used to ensure all the structure members have a big-endian
interpretation (the compiler would automatically insert byte swap
instructions before and after respective store and load instructions).
- To reproduce
GCC V8 is required to correctly emit DW_AT_endianity DWARF attributes
in all situations when the scalar_storage_order attribute is used.
A fix for (dwarf endianity instrumentation) for GCC V6-V7 can be found
in the URL field of the following PR:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82509
- Test-case:
A new test case (testsuite/gdb.base/endianity.*) is included with this
patch.
Manual testing for mixed endianity code has also been done with GCC V8.
See:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82509#c4
- Observed vs. expected:
Without this change, using scalar_storage_order that doesn't match the
target, such as
struct otherendian
{
int v;
} __attribute__( ( scalar_storage_order( "big-endian" ) ) );
would behave like the following on a little endian target:
Breakpoint 1 at 0x401135: file endianity.c, line 41.
(gdb) run
Starting program: /home/pjoot/freeware/t/a.out
Missing separate debuginfos, use: debuginfo-install glibc-2.17-292.el7.x86_64
Breakpoint 1, main () at endianity.c:41
41 struct otherendian o = {3};
(gdb) n
43 do_nothing (&o); /* START */
(gdb) p o
$1 = {v = 50331648}
(gdb) p /x
$2 = {v = 0x3000000}
whereas with this gdb enhancement we can access the variable with the user
specified endianity:
Breakpoint 1, main () at endianity.c:41
41 struct otherendian o = {3};
(gdb) p o
$1 = {v = 0}
(gdb) n
43 do_nothing (&o); /* START */
(gdb) p o
$2 = {v = 3}
(gdb) p o.v = 4
$3 = 4
(gdb) p o.v
$4 = 4
(gdb) x/4xb &o.v
0x7fffffffd90c: 0x00 0x00 0x00 0x04
(observe that the 4 byte int variable has a big endian representation in the
hex dump.)
gdb/ChangeLog
2019-11-21 Peeter Joot <peeter.joot@lzlabs.com>
Byte reverse display of variables with DW_END_big, DW_END_little
(DW_AT_endianity) dwarf attributes if different than the native
byte order.
* ada-lang.c (ada_value_binop):
Use type_byte_order instead of gdbarch_byte_order.
* ada-valprint.c (printstr):
(ada_val_print_string):
* ada-lang.c (value_pointer):
(ada_value_binop):
Use type_byte_order instead of gdbarch_byte_order.
* c-lang.c (c_get_string):
Use type_byte_order instead of gdbarch_byte_order.
* c-valprint.c (c_val_print_array):
Use type_byte_order instead of gdbarch_byte_order.
* cp-valprint.c (cp_print_class_member):
Use type_byte_order instead of gdbarch_byte_order.
* dwarf2loc.c (rw_pieced_value):
Use type_byte_order instead of gdbarch_byte_order.
* dwarf2read.c (read_base_type): Handle DW_END_big,
DW_END_little
* f-lang.c (f_get_encoding):
Use type_byte_order instead of gdbarch_byte_order.
* findvar.c (default_read_var_value):
Use type_byte_order instead of gdbarch_byte_order.
* gdbtypes.c (check_types_equal):
Require matching TYPE_ENDIANITY_NOT_DEFAULT if set.
(recursive_dump_type): Print TYPE_ENDIANITY_BIG,
and TYPE_ENDIANITY_LITTLE if set.
(type_byte_order): new function.
* gdbtypes.h (TYPE_ENDIANITY_NOT_DEFAULT): New macro.
(struct main_type) <flag_endianity_not_default>:
New field.
(type_byte_order): New function.
* infcmd.c (default_print_one_register_info):
Use type_byte_order instead of gdbarch_byte_order.
* p-lang.c (pascal_printstr):
Use type_byte_order instead of gdbarch_byte_order.
* p-valprint.c (pascal_val_print):
Use type_byte_order instead of gdbarch_byte_order.
* printcmd.c (print_scalar_formatted):
Use type_byte_order instead of gdbarch_byte_order.
* solib-darwin.c (darwin_current_sos):
Use type_byte_order instead of gdbarch_byte_order.
* solib-svr4.c (solib_svr4_r_ldsomap):
Use type_byte_order instead of gdbarch_byte_order.
* stap-probe.c (stap_modify_semaphore):
Use type_byte_order instead of gdbarch_byte_order.
* target-float.c (target_float_same_format_p):
Use type_byte_order instead of gdbarch_byte_order.
* valarith.c (scalar_binop):
(value_bit_index):
Use type_byte_order instead of gdbarch_byte_order.
* valops.c (value_cast):
Use type_byte_order instead of gdbarch_byte_order.
* valprint.c (generic_emit_char):
(generic_printstr):
(val_print_string):
Use type_byte_order instead of gdbarch_byte_order.
* value.c (unpack_long):
(unpack_bits_as_long):
(unpack_value_bitfield):
(modify_field):
(pack_long):
(pack_unsigned_long):
Use type_byte_order instead of gdbarch_byte_order.
* findvar.c (unsigned_pointer_to_address):
(signed_pointer_to_address):
(unsigned_address_to_pointer):
(address_to_signed_pointer):
(default_read_var_value):
(default_value_from_register):
Use type_byte_order instead of gdbarch_byte_order.
* gnu-v3-abi.c (gnuv3_make_method_ptr):
Use type_byte_order instead of gdbarch_byte_order.
* riscv-tdep.c (riscv_print_one_register_info):
Use type_byte_order instead of gdbarch_byte_order.
gdb/testsuite/ChangeLog
2019-11-21 Peeter Joot <peeter.joot@lzlabs.com>
* gdb.base/endianity.c: New test.
* gdb.base/endianity.exp: New file.
Change-Id: I4bd98c1b4508c2d7c5a5dbb15d7b7b1cb4e667e2
In Ada, the programmer can request that a range type with a non-zero
base be stored in the minimal number of bits required for the range.
This is done by biasing the values; so, for example, a range of -7..-4
may be stored as two bits with a bias of -7.
This patch implements this for gdb. It is done by adding a bias to
struct range_bounds and then adjusting a few spots to handle this.
The test case is written to use -fgnat-encodings=minimal, but a future
compiler patch will change the compiler to emit DW_AT_GNU_bias with
-fgnat-encodings=gdb. It seemed good to get the gdb patch in first.
Tested on x86-64 Fedora 29; plus a variety of targets using AdaCore's
internal test suite.
gdb/ChangeLog
2019-09-03 Tom Tromey <tromey@adacore.com>
* ada-valprint.c (ada_val_print_num): Don't recurse for range
types.
(has_negatives): Unbias a range type bound.
* dwarf2read.c (read_subrange_type): Handle DW_AT_GNU_bias.
* gdbtypes.c (operator==): Handle new field.
(create_range_type): Add "bias" parameter.
(create_static_range_type, resolve_dynamic_range): Update.
* gdbtypes.h (struct range_bounds) <bias>: New member.
(create_range_type): Add bias parameter.
* printcmd.c (print_scalar_formatted): Unbias range types.
* value.c (unpack_long): Unbias range types.
(pack_long): Bias range types.
gdb/testsuite/ChangeLog
2019-09-03 Tom Tromey <tromey@adacore.com>
* gdb.ada/bias.exp: New file.
* gdb.ada/bias/bias.adb: New file.
* gdb.ada/print_chars.exp: Add regression test.
* gdb.ada/print_chars/foo.adb (My_Character): New type.
(MC): New variable.
If a DW_TAG_subrange_type DWARF entry has no DW_AT_type then a default
type based on the size of an address on the current target is assumed.
We store this type as the target type for GDB's range types.
Currently GDB can create ranges for which the target type is VOID,
this is incorrect but seems to cause no problems. I believe the reason
this doesn't cause any issues is because the languages (for example
Ada) that actually make use of a ranges target type also have
compilers that generate DWARF that includes a DW_AT_type attribute.
However, gfortran does not include a DW_AT_type, its DWARF instead
relies on the default target type. This isn't currently a problem for
GDB as gfortran doesn't make use of the target type when printing
subranges, but it shouldn't hurt to fix this issue now.
I've added an assert into create_range_type that will catch this issue
if it comes up again.
This was tested on an x86-64/GNU-Linux machine with both the Ada and
gfortran compilers available with both '--target_board=unix' and
'--target_board=unix/-m32'. There are no user visible changes after
this commit.
gdb/ChangeLog:
* dwarf2read.c (read_subrange_index_type): New function.
(read_subrange_type): Move code into new function and call it.
* gdbtypes.c (create_range_type): Add some asserts.
Convert dwarf2_evaluate_property to return a bool, there should be no
user visible change after this commit.
gdb/ChangeLog:
* dwarf2loc.c (dwarf2_evaluate_property): Change return type, and
update return statements.
* dwarf2loc.h (dwarf2_evaluate_property): Update return type on
declaration, and update comment to match.
* gdbtypes.c (resolve_dynamic_array): Update call to
dwarf2_evaluate_property to match new return type.
This changes gdbtypes.c to use the type-safe registry API.
gdb/ChangeLog
2019-05-08 Tom Tromey <tom@tromey.com>
* gdbtypes.c (objfile_type_data): Change type.
(objfile_type, _initialize_gdbtypes): Update.
The current code in gdbtypes.c:type_align incorrectly returns 0 as the
alignment for a structure containing only static fields. After this
patch the correct value of 1 is returned. The gdb.base/align.exp test
is extended to cover this case.
gdb/ChangeLog:
* gdbtypes.c (type_align): A struct with no non-static fields also
has alignment of 1.
gdb/testsuite/ChangeLog:
* gdb.base/align.exp: Extend test to cover structures containing
only static fields.
This rewrites gdb's TRY/CATCH to plain C++ try/catch. The patch was
largely written by script, though one change (to a comment in
common-exceptions.h) was reverted by hand.
gdb/ChangeLog
2019-04-08 Tom Tromey <tom@tromey.com>
* xml-support.c: Use C++ exception handling.
* x86-linux-nat.c: Use C++ exception handling.
* windows-nat.c: Use C++ exception handling.
* varobj.c: Use C++ exception handling.
* value.c: Use C++ exception handling.
* valprint.c: Use C++ exception handling.
* valops.c: Use C++ exception handling.
* unittests/parse-connection-spec-selftests.c: Use C++ exception
handling.
* unittests/cli-utils-selftests.c: Use C++ exception handling.
* typeprint.c: Use C++ exception handling.
* tui/tui.c: Use C++ exception handling.
* tracefile-tfile.c: Use C++ exception handling.
* top.c: Use C++ exception handling.
* thread.c: Use C++ exception handling.
* target.c: Use C++ exception handling.
* symmisc.c: Use C++ exception handling.
* symfile-mem.c: Use C++ exception handling.
* stack.c: Use C++ exception handling.
* sparc64-linux-tdep.c: Use C++ exception handling.
* solib.c: Use C++ exception handling.
* solib-svr4.c: Use C++ exception handling.
* solib-spu.c: Use C++ exception handling.
* solib-frv.c: Use C++ exception handling.
* solib-dsbt.c: Use C++ exception handling.
* selftest-arch.c: Use C++ exception handling.
* s390-tdep.c: Use C++ exception handling.
* rust-lang.c: Use C++ exception handling.
* rust-exp.y: Use C++ exception handling.
* rs6000-tdep.c: Use C++ exception handling.
* rs6000-aix-tdep.c: Use C++ exception handling.
* riscv-tdep.c: Use C++ exception handling.
* remote.c: Use C++ exception handling.
* remote-fileio.c: Use C++ exception handling.
* record-full.c: Use C++ exception handling.
* record-btrace.c: Use C++ exception handling.
* python/python.c: Use C++ exception handling.
* python/py-value.c: Use C++ exception handling.
* python/py-utils.c: Use C++ exception handling.
* python/py-unwind.c: Use C++ exception handling.
* python/py-type.c: Use C++ exception handling.
* python/py-symbol.c: Use C++ exception handling.
* python/py-record.c: Use C++ exception handling.
* python/py-record-btrace.c: Use C++ exception handling.
* python/py-progspace.c: Use C++ exception handling.
* python/py-prettyprint.c: Use C++ exception handling.
* python/py-param.c: Use C++ exception handling.
* python/py-objfile.c: Use C++ exception handling.
* python/py-linetable.c: Use C++ exception handling.
* python/py-lazy-string.c: Use C++ exception handling.
* python/py-infthread.c: Use C++ exception handling.
* python/py-inferior.c: Use C++ exception handling.
* python/py-gdb-readline.c: Use C++ exception handling.
* python/py-framefilter.c: Use C++ exception handling.
* python/py-frame.c: Use C++ exception handling.
* python/py-finishbreakpoint.c: Use C++ exception handling.
* python/py-cmd.c: Use C++ exception handling.
* python/py-breakpoint.c: Use C++ exception handling.
* python/py-arch.c: Use C++ exception handling.
* printcmd.c: Use C++ exception handling.
* ppc-linux-tdep.c: Use C++ exception handling.
* parse.c: Use C++ exception handling.
* p-valprint.c: Use C++ exception handling.
* objc-lang.c: Use C++ exception handling.
* mi/mi-main.c: Use C++ exception handling.
* mi/mi-interp.c: Use C++ exception handling.
* mi/mi-cmd-stack.c: Use C++ exception handling.
* mi/mi-cmd-break.c: Use C++ exception handling.
* main.c: Use C++ exception handling.
* linux-thread-db.c: Use C++ exception handling.
* linux-tdep.c: Use C++ exception handling.
* linux-nat.c: Use C++ exception handling.
* linux-fork.c: Use C++ exception handling.
* linespec.c: Use C++ exception handling.
* language.c: Use C++ exception handling.
* jit.c: Use C++ exception handling.
* infrun.c: Use C++ exception handling.
* infcmd.c: Use C++ exception handling.
* infcall.c: Use C++ exception handling.
* inf-loop.c: Use C++ exception handling.
* i386-tdep.c: Use C++ exception handling.
* i386-linux-tdep.c: Use C++ exception handling.
* guile/scm-value.c: Use C++ exception handling.
* guile/scm-type.c: Use C++ exception handling.
* guile/scm-symtab.c: Use C++ exception handling.
* guile/scm-symbol.c: Use C++ exception handling.
* guile/scm-pretty-print.c: Use C++ exception handling.
* guile/scm-ports.c: Use C++ exception handling.
* guile/scm-param.c: Use C++ exception handling.
* guile/scm-math.c: Use C++ exception handling.
* guile/scm-lazy-string.c: Use C++ exception handling.
* guile/scm-frame.c: Use C++ exception handling.
* guile/scm-disasm.c: Use C++ exception handling.
* guile/scm-cmd.c: Use C++ exception handling.
* guile/scm-breakpoint.c: Use C++ exception handling.
* guile/scm-block.c: Use C++ exception handling.
* guile/guile-internal.h: Use C++ exception handling.
* gnu-v3-abi.c: Use C++ exception handling.
* gdbtypes.c: Use C++ exception handling.
* frame.c: Use C++ exception handling.
* frame-unwind.c: Use C++ exception handling.
* fbsd-tdep.c: Use C++ exception handling.
* f-valprint.c: Use C++ exception handling.
* exec.c: Use C++ exception handling.
* event-top.c: Use C++ exception handling.
* event-loop.c: Use C++ exception handling.
* eval.c: Use C++ exception handling.
* dwarf2read.c: Use C++ exception handling.
* dwarf2loc.c: Use C++ exception handling.
* dwarf2-frame.c: Use C++ exception handling.
* dwarf2-frame-tailcall.c: Use C++ exception handling.
* dwarf-index-write.c: Use C++ exception handling.
* dwarf-index-cache.c: Use C++ exception handling.
* dtrace-probe.c: Use C++ exception handling.
* disasm-selftests.c: Use C++ exception handling.
* darwin-nat.c: Use C++ exception handling.
* cp-valprint.c: Use C++ exception handling.
* cp-support.c: Use C++ exception handling.
* cp-abi.c: Use C++ exception handling.
* corelow.c: Use C++ exception handling.
* completer.c: Use C++ exception handling.
* compile/compile-object-run.c: Use C++ exception handling.
* compile/compile-object-load.c: Use C++ exception handling.
* compile/compile-cplus-symbols.c: Use C++ exception handling.
* compile/compile-c-symbols.c: Use C++ exception handling.
* common/selftest.c: Use C++ exception handling.
* common/new-op.c: Use C++ exception handling.
* cli/cli-script.c: Use C++ exception handling.
* cli/cli-interp.c: Use C++ exception handling.
* cli/cli-cmds.c: Use C++ exception handling.
* c-varobj.c: Use C++ exception handling.
* btrace.c: Use C++ exception handling.
* breakpoint.c: Use C++ exception handling.
* break-catch-throw.c: Use C++ exception handling.
* arch-utils.c: Use C++ exception handling.
* amd64-tdep.c: Use C++ exception handling.
* ada-valprint.c: Use C++ exception handling.
* ada-typeprint.c: Use C++ exception handling.
* ada-lang.c: Use C++ exception handling.
* aarch64-tdep.c: Use C++ exception handling.
gdb/gdbserver/ChangeLog
2019-04-08 Tom Tromey <tom@tromey.com>
* server.c: Use C++ exception handling.
* linux-low.c: Use C++ exception handling.
* gdbreplay.c: Use C++ exception handling.
This series is revisit of Siddhesh Poyarekar's patch from back in
2012. The last status on the patch is in the following gdb-patches
thread:
https://sourceware.org/ml/gdb-patches/2012-08/msg00562.html
It appears that Tom approved the patch, but Jan had some issues
with a compiler error that made the test fail on -m32 test runs.
He wrote up a hand-tweaked .S file to deal with it. Siddesh said
he would update tests. Then nothing.
Siddesh and Jan have both moved on since.
The patch originally required a large precursor patch to work.
I have whittled this down to/rewritten the bare minimum, and this
first patch is the result, changing the type of TYPE_LENGTH
to ULONGEST from unsigned int.
The majority of the changes involve changing printf format
strings to use %s and pulongest instead of %d.
gdb/ChangeLog:
* ada-lang.c (ada_template_to_fixed_record_type_1): Use
%s/pulongest for TYPE_LENGTH instead of %d in format
strings.
* ada-typerint.c (ada_print_type): Likewise.
* amd64-windows-tdep.c (amd64_windows_store_arg_in_reg): Likewise.
* compile/compile-c-support.c (generate_register_struct): Likewise.
* gdbtypes.c (recursive_dump_type): Likewise.
* gdbtypes.h (struct type) <length>: Change type to ULONGEST.
* m2-typeprint.c (m2_array): Use %s/pulongest for TYPE_LENGTH
instead of %d in format strings.
* riscv-tdep.c (riscv_type_alignment): Cast second argument
to std::min to ULONGEST.
* symmisc.c (print_symbol): Use %s/pulongest for TYPE_LENGTH
instead of %d in format strings.
* tracepoint.c (info_scope_command): Likewise.
* typeprint.c (print_offset_data::update)
(print_offset_data::finish): Likewise.
* xtensa-tdep.c (xtensa_store_return_value)
(xtensa_push_dummy_call): Likewise.
I noticed that there are still many places referring to non-const
blocks. This constifies all the remaining ones that I found that
could be constified.
In a few spots, this search found unused variables or fields. I
removed these. I've also removed some unnecessary casts to
"struct block *".
gdb/ChangeLog
2019-03-24 Tom Tromey <tom@tromey.com>
* c-exp.y (typebase): Remove casts.
* gdbtypes.c (lookup_unsigned_typename, )
(lookup_signed_typename): Remove cast.
* eval.c (parse_to_comma_and_eval): Remove cast.
* parse.c (write_dollar_variable): Remove cast.
* block.h (struct block) <superblock>: Now const.
* symfile-debug.c (debug_qf_map_matching_symbols): Update.
* psymtab.c (psym_map_matching_symbols): Make "block" const.
(map_block): Make "block" const.
* symfile.h (struct quick_symbol_functions)
<map_matching_symbols>: Constify block argument to "callback".
* symtab.c (basic_lookup_transparent_type_quick): Make "block"
const.
(find_pc_sect_compunit_symtab): Make "b" const.
(find_symbol_at_address): Likewise.
(search_symbols): Likewise.
* dwarf2read.c (dw2_lookup_symbol): Make "block" const.
(dw2_debug_names_lookup_symbol): Likewise.
(dw2_map_matching_symbols): Update.
* p-valprint.c (pascal_val_print): Remove "block".
* ada-lang.c (ada_add_global_exceptions): Make "b" const.
(aux_add_nonlocal_symbols): Make "block" const.
(resolve_subexp): Remove cast.
* linespec.c (iterate_over_all_matching_symtabs): Make "block"
const.
(iterate_over_file_blocks): Likewise.
* f-exp.y (%union) <bval>: Remove.
* coffread.c (patch_opaque_types): Make "b" const.
* spu-tdep.c (spu_catch_start): Make "block" const.
* c-valprint.c (print_unpacked_pointer): Remove "block".
* symmisc.c (dump_symtab_1): Make "b" const.
(block_depth): Make "block" const.
* d-exp.y (%union) <bval>: Remove.
* cp-support.h (cp_lookup_rtti_type): Update.
* cp-support.c (cp_lookup_rtti_type): Make "block" const.
* psymtab.c (psym_lookup_symbol): Make "block" const.
(maintenance_check_psymtabs): Make "b" const.
* python/py-framefilter.c (extract_sym): Make "sym_block" const.
(enumerate_locals, enumerate_args): Update.
* python/py-symtab.c (stpy_global_block): Make "block" const.
(stpy_static_block): Likewise.
* inline-frame.c (block_starting_point_at): Make "new_block"
const.
* block.c (find_block_in_blockvector): Make return type const.
(blockvector_for_pc_sect): Make "b" const.
(find_block_in_blockvector): Make "b" const.
lookup_struct_elt is a new function which returns a tuple of
information about a component of a structure or union. The returned
tuple contains a pointer to the struct field object for the component
as well as a bit offset of that field within the structure. If the
field names a field in an anonymous substructure, the offset is the
"global" offset relative to the original structure type. If noerr is
set, then the returned tuple will set the field pointer to NULL to
indicate a missing component rather than throwing an error.
lookup_struct_elt_type is now reimplemented in terms of this new
function. It simply returns the type of the returned field.
gdb/ChangeLog:
* gdbtypes.c (lookup_struct_elt): New function.
(lookup_struct_elt_type): Reimplement via lookup_struct_elt.
* gdbtypes.h (struct struct_elt): New type.
(lookup_struct_elt): New prototype.
Update the comment above the function to reflect the code removal and
document the existing behavior.
gdb/ChangeLog:
* gdbtypes.c (lookup_struct_elt_type): Update comment and
remove disabled code block.
We return INCOMPATIBLE_TYPE_BADNESS for all these type codes, so we might as
well just let them go to the default case.
Incidentally, this patch also makes this false positive error go away when
compiling with gcc (Ubuntu 7.3.0-27ubuntu1~18.04) 7.3.0, default compiler on
Ubuntu 18.04.
CXX gdbtypes.o
/home/smarchi/src/binutils-gdb/gdb/gdbtypes.c: In function ‘rank rank_one_type(type*, type*, value*)’:
/home/smarchi/src/binutils-gdb/gdb/gdbtypes.c:4259:1: error: control reaches end of non-void function [-Werror=return-type]
}
^
gdb/ChangeLog:
* gdbtypes.c (rank_one_type): Remove unnecessary cases from switch.
In 'type_align' when computing the alignment of a structure we should
not consider the alignment of static structure members, these are
usually stored outside of the structure and therefore don't have any
impact on the structures alignment requirements.
I've extended the existing alignment calculating test to compile in
both C and C++ now so that we can create structures with static
members.
gdb/ChangeLog:
* gdbtypes.c (type_align): Don't consider static members when
computing structure alignment.
gdb/testsuite/ChangeLog:
* gdb.base/align.exp: Extend to compile in both C and C++, and add
tests for structs with static members.
This commit restructures the relationship between the type_align
function and the gdbarch_type_align method.
The problem being addressed with this commit is this; previously the
type_align function was structured so that for "basic" types (int,
float, etc) the gdbarch_type_align hook was called, which for
"compound" types (arrays, structs, etc) the common type_align code has
a fixed method for how to extract a "basic" type and would then call
itself on that "basic" type.
The problem is that if an architecture wants to modify the alignment
rules for a "compound" type then this is not currently possible.
In the revised structure, all types pass through the
gdbarch_type_align method. If this method returns 0 then this
indicates that the architecture has no special rules for this type,
and GDB should apply the default rules for alignment. However, the
architecture is free to provide an alignment for any type, both
"basic" and "compound".
After this commit the default alignment rules now all live in the
type_align function, the default_type_align only ever returns 0,
meaning apply the default rules.
I've updated the 3 targets (arc, i386, and nios2) that already
override the gdbarch_type_align method to fit the new scheme.
Tested on X86-64/GNU Linux with no regressions.
gdb/ChangeLog:
* arc-tdep.c (arc_type_align): Provide alignment for basic types,
return 0 for other types.
* arch-utils.c (default_type_align): Always return 0.
* gdbarch.h: Regenerate.
* gdbarch.sh (type_align): Extend comment.
* gdbtypes.c (type_align): Add additional comments, always call
gdbarch_type_align before applying the default rules.
* i386-tdep.c (i386_type_align): Return 0 as the default rule,
generic code will then apply a suitable default.
* nios2-tdep.c (nios2_type_align): Provide alignment for basic
types, return 0 for other types.
The code in type_align (gdbtypes.c) currently hard-codes the rules for
aligning method and member pointers. It would seem better to forward
these types through the gdbarch hook, so that an architecture could
override the alignment of these types if needed.
Only 3 architectures currently override the gdbarch alignment hook,
these are arc, i386, and nio2.
For arc and nios the alignment rules are that alignment is the minimum
of 4-bytes and the type length. As pointers are 4-bytes on these
targets, then (assuming method and members pointers are also 4-bytes)
there should be no change to the alignment after this patch.
For i386 the gdbarch alignment hook overrides for some INT and FLOAT
types only. For method and member pointers we align on the type size
still, so there should be no change to the alignment after this patch.
I tested this on x86-64 GNU Linux with no regressions.
gdb/ChangeLog:
* gdbtypes.c (type_align): Allow alignment of TYPE_CODE_METHODPTR
and TYPE_CODE_MEMBERPTR to be overridden by the gdbarch.
This commit enhances type_align to handle TYPE_CODE_RANGE types
the same as integers and enums, rather than returning zero,
which means for this function that it could not determine its
alignment.
gdb/ChangeLog:
* gdbtypes.c (type_align): Handle TYPE_CODE_RANGE the same as
integers and enumeration types.
Tested on x86_64-linux. Also tested on a variety of platforms
(with CPUs being ARM, AArch64, Leon3 (SPARC-like), PowerPC,
PowerPC64, RV64, Visium, x86, x86_64).
An upcoming sync with gcc's libiberty [1] will remove support for old
mangling schemes (GNU v2, Lucid, ARM, HP and EDG). It will remove the
cplus_demangle_opname function, so we need to get rid of its usages in
GDB (it's a GNU v2 specific function).
I think the changes are mostly relatively obvious, some hacks that were
necessary to support overloaded operators with GNU v2 mangling are not
needed anymore.
The change in stabsread.c is perhaps less obvious. I think we could get
rid of more code in that region that is specific to old mangling
schemes, but I chose to do only the minimal changes required to remove
the cplus_demangle_opname uses. There is also a detailed comment just
above that explaining how GNU v2 and v3 mangled symbols are handled, I
decided to leave it as-is, since I wasn't sure which part to remove,
change or leave there.
[1] The commit "Remove support for demangling GCC 2.x era mangling
schemes.", specifically.
gdb/ChangeLog:
* gdbtypes.c (check_stub_method_group): Remove handling of old
mangling schemes.
* linespec.c (find_methods): Likewise.
* stabsread.c (read_member_functions): Likewise.
* valops.c (search_struct_method): Likewise.
(value_struct_elt_for_reference): Likewise.
* NEWS: Mention this change.
gdb/testsuite/ChangeLog:
* gdb.cp/demangle.exp (test_gnu_style_demangling): Rename to...
(test_gnuv3_style_demangling): ... this.
(test_lucid_style_demangling): Remove.
(test_arm_style_demangling): Remove.
(test_hp_style_demangling): Remove.
(do_tests): Remove calls to the above.
gdb/doc/ChangeLog:
* gdb.texinfo (Print Settings): Remove mention of specific
demangle-style values, just refer to the in-process help.
This commit applies all changes made after running the gdb/copyright.py
script.
Note that one file was flagged by the script, due to an invalid
copyright header
(gdb/unittests/basic_string_view/element_access/char/empty.cc).
As the file was copied from GCC's libstdc++-v3 testsuite, this commit
leaves this file untouched for the time being; a patch to fix the header
was sent to gcc-patches first.
gdb/ChangeLog:
Update copyright year range in all GDB files.
badness_vector is currently an open coded vector. This reimplements
it as a std::vector.
This fixes a few leaks as well:
- find_oload_champ is leaking every badness vector calculated bar the
one returned.
- bv->rank is always leaked, since callers of rank_function only
xfree the badness_vector pointer, not bv->rank.
gdb/ChangeLog:
2018-11-21 Pedro Alves <palves@redhat.com>
* gdbtypes.c (compare_badness): Change type of parameters to const
reference. Adjust to badness_vector being a std::vector now.
(rank_function): Adjust to badness_vector being a std::vector now.
* gdbtypes.h (badness_vector): Now a typedef to std::vector.
(LENGTH_MATCH): Delete.
(compare_badness): Change type of parameters to const reference.
(rank_function): Return a badness_vector by value now.
(find_overload_match): Adjust to badness_vector being a
std::vector now. Remove cleanups.
(find_oload_champ_namespace): 'oload_champ_bv' parameter now a
badness_vector pointer.
(find_oload_champ_namespace_loop): 'oload_champ_bv' parameter now
a badness_vector pointer. Adjust to badness_vector being a
std::vector now. Remove cleanups.
(find_oload_champ): 'oload_champ_bv' parameter now
a badness_vector pointer. Adjust to badness_vector being a
std::vector now. Remove cleanups.
This replaces more pointer+length with gdb::array_view. This time,
around invoke_xmethod, and then propagating the fallout around, which
inevitably leaks to the overload resolution code.
There are several places in the code that want to grab a slice of an
array, by advancing the array pointer, and decreasing the length
pointer. This patch introduces a pair of new
gdb::array_view::slice(...) methods to make that convenient and clear.
Unit test included.
gdb/ChangeLog:
2018-11-21 Pedro Alves <palves@redhat.com>
* common/array-view.h (array_view::splice(size_type, size_t)): New.
(array_view::splice(size_type)): New.
* eval.c (eval_call, evaluate_funcall): Adjust to use array_view.
* extension.c (xmethod_worker::get_arg_types): Adjust to return an
std::vector.
(xmethod_worker::get_result_type): Adjust to use gdb::array_view.
* extension.h: Include "common/array-view.h".
(xmethod_worker::invoke): Adjust to use gdb::array_view.
(xmethod_worker::get_arg_types): Adjust to return an std::vector.
(xmethod_worker::get_result_type): Adjust to use gdb::array_view.
(xmethod_worker::do_get_arg_types): Adjust to use std::vector.
(xmethod_worker::do_get_result_type): Adjust to use
gdb::array_view.
* gdbtypes.c (rank_function): Adjust to use gdb::array_view.
* gdbtypes.h: Include "common/array-view.h".
(rank_function): Adjust to use gdb::array_view.
* python/py-xmethods.c (python_xmethod_worker::invoke)
(python_xmethod_worker::do_get_arg_types)
(python_xmethod_worker::do_get_result_type)
(python_xmethod_worker::invoke): Adjust to new interfaces.
* valarith.c (value_user_defined_cpp_op, value_user_defined_op)
(value_x_binop, value_x_unop): Adjust to use gdb::array_view.
* valops.c (find_overload_match, find_oload_champ_namespace)
(find_oload_champ_namespace_loop, find_oload_champ): Adjust to use
gdb:array_view and the new xmethod_worker interfaces.
* value.c (result_type_of_xmethod, call_xmethod): Adjust to use
gdb::array_view.
* value.h (find_overload_match, result_type_of_xmethod)
(call_xmethod): Adjust to use gdb::array_view.
* unittests/array-view-selftests.c: Add slicing tests.
This patch started as an observation from valgrind that GDB appeared
to be loosing track of some memory associated with types. An example
valgrind stack would be:
24 bytes in 1 blocks are possibly lost in loss record 419 of 5,361
at 0x4C2EA1E: calloc (vg_replace_malloc.c:711)
by 0x623D26: xcalloc (common-utils.c:85)
by 0x623D65: xzalloc(unsigned long) (common-utils.c:95)
by 0x72A066: make_function_type(type*, type**) (gdbtypes.c:510)
by 0x72A098: lookup_function_type(type*) (gdbtypes.c:521)
by 0x73635D: gdbtypes_post_init(gdbarch*) (gdbtypes.c:5439)
by 0x727590: gdbarch_data(gdbarch*, gdbarch_data*) (gdbarch.c:5230)
by 0x735B99: builtin_type(gdbarch*) (gdbtypes.c:5313)
by 0x514D95: elf_rel_plt_read(minimal_symbol_reader&, objfile*, bfd_symbol**) (elfread.c:542)
by 0x51662F: elf_read_minimal_symbols(objfile*, int, elfinfo const*) (elfread.c:1121)
by 0x5168A5: elf_symfile_read(objfile*, enum_flags<symfile_add_flag>) (elfread.c:1207)
by 0x8520F5: read_symbols(objfile*, enum_flags<symfile_add_flag>) (symfile.c:794)
When we look in make_function_type we find a call to TYPE_ZALLOC
(inside the INIT_FUNC_SPECIFIC macro). It is this call to TYPE_ZALLOC
that is allocating memory with xcalloc, that is then getting lost.
The problem is tht calling TYPE_ALLOC or TYPE_ZALLOC currently
allocates memory from either the objfile obstack or by using malloc.
The problem with this is that types are allocated either on the
objfile obstack, or on the gdbarch obstack.
As a result, if we discard a type associated with an objfile then
auxiliary data allocated with TYPE_(Z)ALLOC will be correctly
discarded. But, if we were ever to discard a gdbarch then any
auxiliary type data would be leaked. Right now there are very few
places in GDB where a gdbarch is ever discarded, but it shouldn't hurt
to close down these bugs as we spot them.
This commit ensures that auxiliary type data is allocated from the
same obstack as the type itself, which should reduce leaked memory.
The one problem case that I found with this change was in eval.c,
where in one place we allocate a local type structure, and then used
TYPE_ZALLOC to allocate some space for the type. This local type is
neither object file owned, nor gdbarch owned, and so the updated
TYPE_ALLOC code is unable to find an objstack to allocate space on.
My proposed solution for this issue is that the space should be
allocated with a direct call to xzalloc. We could extend TYPE_ALLOC
to check for type->gdbarch being null, and then fall back to a direct
call to xzalloc, however, I think that making this rare case of a
local type require special handling is not a bad thing, this serves to
highlight that clearing up the memory will require special handling
too.
This special case of a local type is interesting as the types owner
field (contained within the main_type) is completely null. While
reflecting on this I looked at how types use the get_type_arch
function. It seems clear that, based on how this is used, it is never
intended that null will be returned from this function. This only
goes to reinforce, how locally alloctaed types, with no owner, are
both special, and need to be handled carefully. To help spot errors
earlier, I added an assert into get_type_arch that the returned arch
is not null.
Inside gdbarch.c I found a few other places where auxiliary type data
was being allocated directly on the heap rather than on the types
obstack. I have fixed these to call TYPE_ALLOC now.
Finally, it is worth noting that as we don't clean up our gdbarch
objects yet, then this will not make much of an impact on the amount
of memory reported as lost at program termination time. Memory
allocated for auxiliary type information is still not freed, however,
it is now on the correct obstack. If we do ever start freeing our
gdbarch structures then the associated type data will be cleaned up
correctly.
Tested on X86-64 GNU/Linux with no regressions.
gdb/ChangeLog:
* eval.c (fake_method::fake_method): Call xzalloc directly for a
type that is neither object file owned, nor gdbarch owned.
* gdbtypes.c (get_type_gdbarch): Add an assert that returned
gdbarch is non-NULL.
(alloc_type_instance): Allocate non-objfile owned types on the
gdbarch obstack.
(copy_type_recursive): Allocate TYPE_FIELDS and TYPE_RANGE_DATA
using TYPE_ALLOC to ensure memory is allocated on the correct
obstack.
* gdbtypes.h (TYPE_ALLOC): Allocate space on either the objfile
obstack, or the gdbarch obstack.
(TYPE_ZALLOC): Rewrite using TYPE_ALLOC.
Add int24 and uint24. These are used by the upcoming S12Z target, but will be
needed for any arch which features 24 bit registers.
* gdb/gdbtypes.h (struct builtin_type): New members builtin_int24
and builtin_uint24;
* gdb/gdbtypes.c: Initialize them.
* gdb/doc/gdb.texinfo (Predefined Target Types): Mention types int24 and uint24.
The type alignment value is returned in 8-bit-bytes instead of target
memory addressable units. For example, on a target with 16-bit-bytes
where sizeof(int) == 1 (one addressable unit), alignof(int) currently
returns 2. After, this patch, it returns 1.
gdb/ChangeLog:
* arch-utils.c (default_type_align): Use type_length_units.
* gdbtypes.c (type_align): Use type_length_units.
TYPE_TAG_NAME has been an occasional source of confusion and bugs. It
seems to me that it is only useful for C and C++ -- but even there,
not so much, because at least with DWARF there doesn't seem to be any
way to wind up with a type where the name and the tag name are both
non-NULL and different.
So, this patch removes TYPE_TAG_NAME entirely. This should save a
little memory, but more importantly, it simplifies this part of gdb.
A few minor test suite adjustments were needed. In some situations
the new code does not yield identical output to the old code.
gdb/ChangeLog
2018-06-01 Tom Tromey <tom@tromey.com>
* valops.c (enum_constant_from_type, value_namespace_elt)
(value_maybe_namespace_elt): Update.
* valarith.c (find_size_for_pointer_math): Update.
* target-descriptions.c (make_gdb_type): Update.
* symmisc.c (print_symbol): Update.
* stabsread.c (define_symbol, read_type)
(complain_about_struct_wipeout, add_undefined_type)
(cleanup_undefined_types_1): Update.
* rust-lang.c (rust_tuple_type_p, rust_slice_type_p)
(rust_range_type_p, val_print_struct, rust_print_struct_def)
(rust_internal_print_type, rust_composite_type)
(rust_evaluate_funcall, rust_evaluate_subexp)
(rust_inclusive_range_type_p): Update.
* python/py-type.c (typy_get_tag): Update.
* p-typeprint.c (pascal_type_print_base): Update.
* mdebugread.c (parse_symbol, parse_type): Update.
* m2-typeprint.c (m2_long_set, m2_record_fields, m2_enum):
Update.
* guile/scm-type.c (gdbscm_type_tag): Update.
* go-lang.c (sixg_string_p): Update.
* gnu-v3-abi.c (build_gdb_vtable_type, build_std_type_info_type):
Update.
* gdbtypes.h (struct main_type) <tag_name>: Remove.
(TYPE_TAG_NAME): Remove.
* gdbtypes.c (type_name_no_tag): Simplify.
(check_typedef, check_types_equal, recursive_dump_type)
(copy_type_recursive, arch_composite_type): Update.
* f-typeprint.c (f_type_print_base): Update. Print "Type" prefix
in summary mode when needed.
* eval.c (evaluate_funcall): Update.
* dwarf2read.c (fixup_go_packaging, read_structure_type)
(process_structure_scope, read_enumeration_type)
(read_namespace_type, read_module_type, determine_prefix): Update.
* cp-support.c (inspect_type): Update.
* coffread.c (process_coff_symbol, decode_base_type): Update.
* c-varobj.c (c_is_path_expr_parent): Update.
* c-typeprint.c (c_type_print_base_struct_union): Update.
(c_type_print_base_1): Update. Print struct/class/union/enum in
summary when using C language.
* ax-gdb.c (gen_struct_ref, gen_namespace_elt)
(gen_maybe_namespace_elt): Update.
* ada-lang.c (ada_type_name): Simplify.
(empty_record, ada_template_to_fixed_record_type_1)
(template_to_static_fixed_type)
(to_record_with_fixed_variant_part, ada_check_typedef): Update.
gdb/testsuite/ChangeLog
2018-06-01 Tom Tromey <tom@tromey.com>
* gdb.xml/tdesc-regs.exp (load_description): Update expected
results.
* gdb.dwarf2/method-ptr.exp: Set language to C++.
* gdb.dwarf2/member-ptr-forwardref.exp: Set language to C++.
* gdb.cp/typeid.exp (do_typeid_tests): Update type_re.
* gdb.base/maint.exp (maint_pass_if): Update.
This removes a VEC from type.c, by using std::vector.
While doing this I also took the opportunity to change
types_deeply_equal to return bool. This caught some weird code in
typy_richcompare, now fixed.
And, since I was changing types_deeply_equal, it seemed like a good
idea to also change types_equal, so this patch includes that as well.
Tested by the buildbot.
ChangeLog
2018-05-29 Tom Tromey <tom@tromey.com>
* python/py-type.c (typy_richcompare): Update.
* guile/scm-type.c (tyscm_equal_p_type_smob): Update.
* gdbtypes.h (types_deeply_equal): Return bool.
(types_equal): Likewise.
* gdbtypes.c (type_equality_entry_d): Remove typedef. Don't
declare VEC.
(check_types_equal): Change worklist to std::vector. Return
bool.
(struct type_equality_entry): Add constructor.
(compare_maybe_null_strings): Return bool.
(check_types_worklist): Return bool. Change worklist to
std::vector.
(types_deeply_equal): Use std::vector.
(types_equal): Return bool.
(compare_maybe_null_strings): Simplify.
This adds some basic type alignment support to gdb. It changes struct
type to store the alignment, and updates dwarf2read.c to handle
DW_AT_alignment. It also adds a new gdbarch method and updates
i386-tdep.c.
None of this new functionality is used anywhere yet, so tests will
wait until the next patch.
2018-04-30 Tom Tromey <tom@tromey.com>
* i386-tdep.c (i386_type_align): New function.
(i386_gdbarch_init): Update.
* gdbarch.sh (type_align): New method.
* gdbarch.c, gdbarch.h: Rebuild.
* arch-utils.h (default_type_align): Declare.
* arch-utils.c (default_type_align): New function.
* gdbtypes.h (TYPE_ALIGN_BITS): New define.
(struct type) <align_log2>: New field.
<instance_flags>: Now a bitfield.
(TYPE_RAW_ALIGN): New macro.
(type_align, type_raw_align, set_type_align): Declare.
* gdbtypes.c (type_align, type_raw_align, set_type_align): New
functions.
* dwarf2read.c (quirk_rust_enum): Set type alignment.
(get_alignment, maybe_set_alignment): New functions.
(read_structure_type, read_enumeration_type, read_array_type)
(read_set_type, read_tag_pointer_type, read_tag_reference_type)
(read_subrange_type, read_base_type): Set type alignment.
After the previous patch, on Fedora 27 (glibc 2.26), if you try
calling strlen in the inferior, you now get:
(top-gdb) p strlen ("hello")
'__strlen_avx2' has unknown return type; cast the call to its declared return type
This is correct, because __strlen_avx2 is written in assembly.
We can improve on this though -- if the final ifunc resolved/target
function has no debug info, but the ifunc _resolver_ does have debug
info, we can try extracting the final function's type from the type
that the resolver returns. E.g.,:
typedef size_t (*strlen_t) (const char*);
size_t my_strlen (const char *) { /* some implementation */ }
strlen_t strlen_resolver (unsigned long hwcap) { return my_strlen; }
extern size_t strlen (const char *s);
__typeof (strlen) strlen __attribute__ ((ifunc ("strlen_resolver")));
In the strlen example above, the resolver returns strlen_t, which is a
typedef for pointer to a function that returns size_t. "strlen_t" is
the type of both the user-visible "strlen", and of the the target
function that implements it.
This patch teaches GDB to extract that type.
This is done for actual inferior function calls (in infcall.c), and
for ptype (in eval_call). By the time we get to either of these
places, we've already lost the original symbol/minsym, and only have
values and types to work with. Hence the changes to c-exp.y and
evaluate_var_msym_value, to ensure that we propagate the ifunc
minsymbol's info.
The change to make ifunc symbols have no/unknown return type exposes a
latent problem -- gdb.compile/compile-ifunc.exp calls a no-debug-info
function, but we did not warn about it. The test is fixed by this
commit too.
gdb/ChangeLog:
2018-04-26 Pedro Alves <palves@redhat.com>
* blockframe.c (find_gnu_ifunc_target_type): New function.
(find_function_type): New.
* eval.c (evaluate_var_msym_value): For GNU ifunc types, always
return a value with a memory address.
(eval_call): For calls to GNU ifunc functions, try to find the
type of the target function from the type that the resolver
returns.
* gdbtypes.c (objfile_type): Don't install a return type for ifunc
symbols.
* infcall.c (find_function_return_type): Delete.
(find_function_addr): Add 'function_type' parameter. For calls to
GNU ifunc functions, try to find the type of the target function
from the type that the resolver returns, and return it via
FUNCTION_TYPE.
(call_function_by_hand_dummy): Adjust to use the function type
returned by find_function_addr.
(find_function_addr): Add 'function_type' parameter and move
description here.
* symtab.h (find_function_type, find_gnu_ifunc_target_type): New
declarations.
gdb/testsuite/ChangeLog:
2018-04-26 Pedro Alves <palves@redhat.com>
* gdb.compile/compile-ifunc.exp: Also expect "function has unknown
return type" warnings.
This patch adds a new class allocate_on_obstack, and let dwarf2_per_objfile
inherit it, so that dwarf2_per_objfile is automatically allocated on
obstack, and "delete dwarf2_per_objfile" doesn't de-allocate any space.
gdb:
2018-02-16 Yao Qi <yao.qi@linaro.org>
* block.c (block_namespace_info): Inherit allocate_on_obstack.
(block_initialize_namespace): Use new.
* dwarf2read.c (dwarf2_per_objfile): Inherit allocate_on_obstack.
(dwarf2_free_objfile): Use delete.
* gdbtypes.c (type_pair): Inherit allocate_on_obstack.
(copy_type_recursive): Use new.
* gdb_obstack.h (allocate_on_obstack): New.
