Commit Graph

1171 Commits

Author SHA1 Message Date
Yao Qi
fd90ace4c1 New class allocate_on_obstack
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.
2018-02-16 16:20:58 +00:00
Tom Tromey
e0cc99a62f Change openp et al to use a unique_xmalloc_ptr
This changes openp, source_full_path_of, and find_and_open_source to
take a unique_xmalloc_ptr, rather than a char*, as an outgoing
argument type.  This simplifies the API, ownership-wise, and allows
for the removal of some cleanups.

gdb/ChangeLog
2018-02-14  Tom Tromey  <tom@tromey.com>

	* symfile.c (symfile_bfd_open): Update.
	* source.h (openp, source_full_path_of, find_and_open_source):
	Change argument type to unique_xmalloc_ptr.
	* source.c (openp): Take a unique_xmalloc_ptr.
	(source_full_path_of, find_and_open_source): Likewise.
	(open_source_file, symtab_to_fullname): Update.
	* solist.h (struct target_so_ops) <find_and_open_solib>: Take a
	unique_xmalloc_ptr.
	* solib.c (solib_find_1): Use unique_xmalloc_ptr.
	(exec_file_find): Update.
	* psymtab.c (psymtab_to_fullname): Update.
	* nto-tdep.h (nto_find_and_open_solib): Update.
	* nto-tdep.c (nto_find_and_open_solib): Change temp_path to a
	unique_xmalloc_ptr.
	* exec.c (exec_file_attach): Update.
	* dwarf2read.c (try_open_dwop_file): Use unique_xmalloc_ptr.
	* cli/cli-cmds.c (find_and_open_script): Use unique_xmalloc_ptr.
2018-02-14 08:09:53 -07:00
Simon Marchi
24b9144d4b Use enum flags for flags passed to openp
gdb/ChangeLog:

	* defs.h (enum openp_flags): New enum.
	(OPF_TRY_CWD_FIRST, OPF_SEARCH_IN_PATH, OPF_RETURN_REALPATH):
	Move to enum openp_flags.
	(openp_flags): New enum flags.
	(openp): Change parameter type to openp_flags.
	* source.c (openp): Change parameter type to openp_flags.
	* cli/cli-cmds.c (find_and_open_script): Use openp_flags.
	* dwarf2read.c (try_open_dwop_file): Use openp_flags.
2018-02-13 12:13:59 -05:00
Andrew Burgess
b303c6f688 gdb: Remove cleanup from dw2_do_instantiate_symtab
When running the test gdb.dwarf2/dw2-bad-parameter-type.exp under
valgrind, I see the following issue reported (on x86-64 Fedora):

  (gdb) ptype f
  ==5203== Invalid read of size 1
  ==5203==    at 0x6931FE: process_die_scope::~process_die_scope() (dwarf2read.c:10642)
  ==5203==    by 0x66818F: process_die(die_info*, dwarf2_cu*) (dwarf2read.c:10664)
  ==5203==    by 0x66A01F: read_file_scope(die_info*, dwarf2_cu*) (dwarf2read.c:11650)
  ==5203==    by 0x667F2D: process_die(die_info*, dwarf2_cu*) (dwarf2read.c:10672)
  ==5203==    by 0x6677B6: process_full_comp_unit(dwarf2_per_cu_data*, language) (dwarf2read.c:10445)
  ==5203==    by 0x66657A: process_queue(dwarf2_per_objfile*) (dwarf2read.c:9945)
  ==5203==    by 0x6559B4: dw2_do_instantiate_symtab(dwarf2_per_cu_data*) (dwarf2read.c:3163)
  ==5203==    by 0x66683D: psymtab_to_symtab_1(partial_symtab*) (dwarf2read.c:10034)
  ==5203==    by 0x66622A: dwarf2_read_symtab(partial_symtab*, objfile*) (dwarf2read.c:9811)
  ==5203==    by 0x787984: psymtab_to_symtab(objfile*, partial_symtab*) (psymtab.c:792)
  ==5203==    by 0x786E3E: psym_lookup_symbol(objfile*, int, char const*, domain_enum_tag) (psymtab.c:522)
  ==5203==    by 0x804BD0: lookup_symbol_via_quick_fns(objfile*, int, char const*, domain_enum_tag) (symtab.c:2383)
  ==5203==  Address 0x147ed063 is 291 bytes inside a block of size 4,064 free'd
  ==5203==    at 0x4C2CD5A: free (vg_replace_malloc.c:530)
  ==5203==    by 0x444415: void xfree<void>(void*) (common-utils.h:60)
  ==5203==    by 0x9DA8C2: call_freefun (obstack.c:103)
  ==5203==    by 0x9DAD35: _obstack_free (obstack.c:280)
  ==5203==    by 0x44464C: auto_obstack::~auto_obstack() (gdb_obstack.h:73)
  ==5203==    by 0x68AFB0: dwarf2_cu::~dwarf2_cu() (dwarf2read.c:25080)
  ==5203==    by 0x68B204: free_one_cached_comp_unit(dwarf2_per_cu_data*) (dwarf2read.c:25174)
  ==5203==    by 0x66668C: dwarf2_release_queue(void*) (dwarf2read.c:9982)
  ==5203==    by 0x563A4C: do_my_cleanups(cleanup**, cleanup*) (cleanups.c:154)
  ==5203==    by 0x563AA7: do_cleanups(cleanup*) (cleanups.c:176)
  ==5203==    by 0x5646CE: throw_exception_cxx(gdb_exception) (common-exceptions.c:289)
  ==5203==    by 0x5647B7: throw_exception(gdb_exception) (common-exceptions.c:317)
  ==5203==  Block was alloc'd at
  ==5203==    at 0x4C2BBAD: malloc (vg_replace_malloc.c:299)
  ==5203==    by 0x564BE8: xmalloc (common-utils.c:44)
  ==5203==    by 0x9DA872: call_chunkfun (obstack.c:94)
  ==5203==    by 0x9DA935: _obstack_begin_worker (obstack.c:141)
  ==5203==    by 0x9DAA3C: _obstack_begin (obstack.c:164)
  ==5203==    by 0x4445E0: auto_obstack::auto_obstack() (gdb_obstack.h:70)
  ==5203==    by 0x68AE07: dwarf2_cu::dwarf2_cu(dwarf2_per_cu_data*) (dwarf2read.c:25073)
  ==5203==    by 0x661A8A: init_cutu_and_read_dies(dwarf2_per_cu_data*, abbrev_table*, int, int, void (*)(die_reader_specs const*, unsigned char const*, die_info*, int, void*), void*) (dwarf2read.c:7869)
  ==5203==    by 0x666A29: load_full_comp_unit(dwarf2_per_cu_data*, language) (dwarf2read.c:10108)
  ==5203==    by 0x655847: load_cu(dwarf2_per_cu_data*) (dwarf2read.c:3120)
  ==5203==    by 0x655928: dw2_do_instantiate_symtab(dwarf2_per_cu_data*) (dwarf2read.c:3148)
  ==5203==    by 0x66683D: psymtab_to_symtab_1(partial_symtab*) (dwarf2read.c:10034)

There's actually a series of three issues reported, but it turns out
they're all related, so we can consider on the first one.

The invalid read is triggered from a destructor which is being invoked
as part of a stack unwind after throwing an error.  At the time the
error is thrown, the stack looks like this:

    #0  0x00000000009f4ecd in __cxa_throw ()
    #1  0x0000000000564761 in throw_exception_cxx (exception=...) at ../../src/gdb/common/common-exceptions.c:303
    #2  0x00000000005647b8 in throw_exception (exception=...) at ../../src/gdb/common/common-exceptions.c:317
    #3  0x00000000005648ff in throw_it(return_reason, errors, const char *, typedef __va_list_tag __va_list_tag *) (reason=RETURN_ERROR,
        error=GENERIC_ERROR, fmt=0xb33020 "Dwarf Error: Cannot find DIE at 0x%x referenced from DIE at 0x%x [in module %s]",
        ap=0x7fff387f2d68) at ../../src/gdb/common/common-exceptions.c:373
    #4  0x0000000000564929 in throw_verror (error=GENERIC_ERROR,
        fmt=0xb33020 "Dwarf Error: Cannot find DIE at 0x%x referenced from DIE at 0x%x [in module %s]", ap=0x7fff387f2d68)
        at ../../src/gdb/common/common-exceptions.c:379
    #5  0x0000000000867be4 in verror (string=0xb33020 "Dwarf Error: Cannot find DIE at 0x%x referenced from DIE at 0x%x [in module %s]",
        args=0x7fff387f2d68) at ../../src/gdb/utils.c:251
    #6  0x000000000056879d in error (fmt=0xb33020 "Dwarf Error: Cannot find DIE at 0x%x referenced from DIE at 0x%x [in module %s]")
        at ../../src/gdb/common/errors.c:43
    #7  0x0000000000686875 in follow_die_ref (src_die=0x30bc8a0, attr=0x30bc8c8, ref_cu=0x7fff387f2ed0) at ../../src/gdb/dwarf2read.c:22969
    #8  0x00000000006844cd in lookup_die_type (die=0x30bc8a0, attr=0x30bc8c8, cu=0x30bc5d0) at ../../src/gdb/dwarf2read.c:21976
    #9  0x0000000000683f27 in die_type (die=0x30bc8a0, cu=0x30bc5d0) at ../../src/gdb/dwarf2read.c:21832
    #10 0x0000000000679b39 in read_subroutine_type (die=0x30bc830, cu=0x30bc5d0) at ../../src/gdb/dwarf2read.c:17343
    #11 0x00000000006845fb in read_type_die_1 (die=0x30bc830, cu=0x30bc5d0) at ../../src/gdb/dwarf2read.c:22035
    #12 0x0000000000684576 in read_type_die (die=0x30bc830, cu=0x30bc5d0) at ../../src/gdb/dwarf2read.c:22010
    #13 0x000000000067003f in read_func_scope (die=0x30bc830, cu=0x30bc5d0) at ../../src/gdb/dwarf2read.c:13822
    #14 0x0000000000667f5e in process_die (die=0x30bc830, cu=0x30bc5d0) at ../../src/gdb/dwarf2read.c:10679
    #15 0x000000000066a020 in read_file_scope (die=0x30bc720, cu=0x30bc5d0) at ../../src/gdb/dwarf2read.c:11650
    #16 0x0000000000667f2e in process_die (die=0x30bc720, cu=0x30bc5d0) at ../../src/gdb/dwarf2read.c:10672
    #17 0x00000000006677b7 in process_full_comp_unit (per_cu=0x3089b80, pretend_language=language_minimal)
        at ../../src/gdb/dwarf2read.c:10445
    #18 0x000000000066657b in process_queue (dwarf2_per_objfile=0x30897d0) at ../../src/gdb/dwarf2read.c:9945
    #19 0x00000000006559b5 in dw2_do_instantiate_symtab (per_cu=0x3089b80) at ../../src/gdb/dwarf2read.c:3163
    #20 0x000000000066683e in psymtab_to_symtab_1 (pst=0x3089bd0) at ../../src/gdb/dwarf2read.c:10034
    #21 0x000000000066622b in dwarf2_read_symtab (self=0x3089bd0, objfile=0x3073f40) at ../../src/gdb/dwarf2read.c:9811
    #22 0x0000000000787985 in psymtab_to_symtab (objfile=0x3073f40, pst=0x3089bd0) at ../../src/gdb/psymtab.c:792
    #23 0x0000000000786e3f in psym_lookup_symbol (objfile=0x3073f40, block_index=1, name=0x30b2e30 "f", domain=VAR_DOMAIN)
        at ../../src/gdb/psymtab.c:522
    #24 0x0000000000804bd1 in lookup_symbol_via_quick_fns (objfile=0x3073f40, block_index=1, name=0x30b2e30 "f", domain=VAR_DOMAIN)
        at ../../src/gdb/symtab.c:2383
    #25 0x0000000000804fe4 in lookup_symbol_in_objfile (objfile=0x3073f40, block_index=1, name=0x30b2e30 "f", domain=VAR_DOMAIN)
        at ../../src/gdb/symtab.c:2558
    #26 0x0000000000805125 in lookup_static_symbol (name=0x30b2e30 "f", domain=VAR_DOMAIN) at ../../src/gdb/symtab.c:2595
    #27 0x0000000000804357 in lookup_symbol_aux (name=0x30b2e30 "f", match_type=symbol_name_match_type::FULL, block=0x0,
        domain=VAR_DOMAIN, language=language_c, is_a_field_of_this=0x0) at ../../src/gdb/symtab.c:2105
    #28 0x0000000000803ad9 in lookup_symbol_in_language (name=0x30b2e30 "f", block=0x0, domain=VAR_DOMAIN, lang=language_c,
        is_a_field_of_this=0x0) at ../../src/gdb/symtab.c:1887
    #29 0x0000000000803b53 in lookup_symbol (name=0x30b2e30 "f", block=0x0, domain=VAR_DOMAIN, is_a_field_of_this=0x0)
        at ../../src/gdb/symtab.c:1899
    #30 0x000000000053b246 in classify_name (par_state=0x7fff387f6090, block=0x0, is_quoted_name=false, is_after_structop=false)
        at ../../src/gdb/c-exp.y:2879
    #31 0x000000000053b7e9 in c_yylex () at ../../src/gdb/c-exp.y:3083
    #32 0x000000000053414a in c_yyparse () at c-exp.c:1903
    #33 0x000000000053c2e7 in c_parse (par_state=0x7fff387f6090) at ../../src/gdb/c-exp.y:3255
    #34 0x0000000000774a02 in parse_exp_in_context_1 (stringptr=0x7fff387f61c0, pc=0, block=0x0, comma=0, void_context_p=0, out_subexp=0x0)
        at ../../src/gdb/parse.c:1213
    #35 0x000000000077476a in parse_exp_in_context (stringptr=0x7fff387f61c0, pc=0, block=0x0, comma=0, void_context_p=0, out_subexp=0x0)
        at ../../src/gdb/parse.c:1115
    #36 0x0000000000774714 in parse_exp_1 (stringptr=0x7fff387f61c0, pc=0, block=0x0, comma=0) at ../../src/gdb/parse.c:1106
    #37 0x0000000000774c53 in parse_expression (string=0x27ff996 "f") at ../../src/gdb/parse.c:1253
    #38 0x0000000000861dc4 in whatis_exp (exp=0x27ff996 "f", show=1) at ../../src/gdb/typeprint.c:472
    #39 0x00000000008620d8 in ptype_command (type_name=0x27ff996 "f", from_tty=1) at ../../src/gdb/typeprint.c:561
    #40 0x000000000047430b in do_const_cfunc (c=0x3012010, args=0x27ff996 "f", from_tty=1) at ../../src/gdb/cli/cli-decode.c:106
    #41 0x000000000047715e in cmd_func (cmd=0x3012010, args=0x27ff996 "f", from_tty=1) at ../../src/gdb/cli/cli-decode.c:1886
    #42 0x00000000008431bb in execute_command (p=0x27ff996 "f", from_tty=1) at ../../src/gdb/top.c:630
    #43 0x00000000006bf946 in command_handler (command=0x27ff990 "ptype f") at ../../src/gdb/event-top.c:583
    #44 0x00000000006bfd12 in command_line_handler (rl=0x30bb3a0 "\240\305\v\003") at ../../src/gdb/event-top.c:774

The problem is that in `process_die` (frames 14 and 16) we create a
`process_die_scope` object, that takes a copy of the `struct
dwarf2_cu *` passed into the frame.  The destructor of the
`process_die_scope` dereferences the stored pointer.  This wouldn't be
an issue, except...

... in dw2_do_instantiate_symtab (frame 19) a clean up was registered that
clears the dwarf2_queue in case of an error.  Part of this clean up
involves deleting the `struct dwarf2_cu`s referenced from the queue..

The problem then, is that cleanups are processed at the site of the
throw, while, class destructors are invoked as we unwind their frame.
The result is that we process the frame 19 cleanup (and delete the
struct dwarf2_cu) before we process the destructors in frames 14 and 16.
When we do get back to frames 14 and 16 the objects being references
have already been deleted.

The solution is to remove the cleanup from dw2_do_instantiate_symtab, and
instead use a destructor to release the dwarf2_queue instead.  With this
patch in place, the valgrind errors are now resolved.

gdb/ChangeLog:

	* dwarf2read.c (dwarf2_release_queue): Delete function, move body
	into...
	(class dwarf2_queue_guard): ...the destructor of this new class.
	(dw2_do_instantiate_symtab): Create instance of the new class
	dwarf2_queue_guard, remove cleanup.
2018-02-12 21:43:45 +00:00
Joel Brobecker
0eb876f52f Move comment in gdb/dwarf2read.c::dwarf2_physname
This commit just moves a comment right next to where it is actually
relevant. No actual code change.

gdb/ChangeLog:

        * dwarf2read.c (dwarf2_physname): Move commment.

Tested by rebuilding GDB.
2018-02-04 23:48:19 -05:00
Simon Marchi
fc8e7e75c2 Remove dwarf2_per_objfile_free and use after free of dwarf2_per_objfile
I got some crashes while doing some work with dwarf2_per_objfile.  It
turns out that dwarf2_per_objfile_free is using the dwarf2_per_objfile
objects after their destructor has ran.

The easiest way to reproduce this is to run the inferior twice (do
"start" twice).  Currently, it goes unnoticed, but when I tried to
change all_comp_units and all_type_units to std::vectors, things started
crashing.

The dwarf2_per_objfile objects get destroyed here:

 #0  dwarf2_per_objfile::~dwarf2_per_objfile (this=0x35afe70, __in_chrg=<optimized out>) at /home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:2422
 #1  0x0000000000833282 in dwarf2_free_objfile (objfile=0x356cff0) at /home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:25363
 #2  0x0000000000699255 in elf_symfile_finish (objfile=0x356cff0) at /home/emaisin/src/binutils-gdb/gdb/elfread.c:1309
 #3  0x0000000000911ed3 in objfile::~objfile (this=0x356cff0, __in_chrg=<optimized out>) at /home/emaisin/src/binutils-gdb/gdb/objfiles.c:674

and just after that the dwarf2read per-objfile registry cleanup function
gets called:

 #0  dwarf2_per_objfile_free (objfile=0x356cff0, d=0x35afe70) at /home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:25667
 ... registry boilerplate ...
 #4  0x00000000009103ea in objfile_free_data (container=0x356cff0) at /home/emaisin/src/binutils-gdb/gdb/objfiles.c:61
 #5  0x0000000000911ee2 in objfile::~objfile (this=0x356cff0, __in_chrg=<optimized out>) at /home/emaisin/src/binutils-gdb/gdb/objfiles.c:678

In dwarf2_per_objfile_free, we access fields of the dwarf2_per_objfile
object, which is invalid since its destructor has been executed.

This patch moves the content of dwarf2_per_objfile_free to the
destructor of dwarf2_per_objfile.  The call to
register_objfile_data_with_cleanup in _initialize_dwarf2_read can be
changed to the simpler register_objfile_data.

gdb/ChangeLog:

	* dwarf2read.c (free_dwo_files): Add forward-declaration.
	(dwarf2_per_objfile::~dwarf2_per_objfile): Move content from
	dwarf2_per_objfile_free here.
	(dwarf2_per_objfile_free): Remove.
	(_initialize_dwarf2_read): Don't register
	dwarf2_per_objfile_free as a registry cleanup.
2018-01-28 12:07:30 -05:00
Joel Brobecker
de4cb04a20 Ada/DWARF: Assume the Ada compiler produces descriptive type attributes
GCC was enhanced in 2011 to generate this attribute, so I think we can
now assume that it is available when using that compiler. Doing so
allows us to speed up what we call "parallel type" lookups when
processing certain types encoded using the GNAT encoding.

This patch changes need_gnat_info to always expect those attributes
to be generated when the language is Ada. This is an assumption
that on the surfcace looks like it might be a bit on the edge; but
in practice, it should be OK because this is only useful in the
context of handling GNAT-specific encodings. Other Ada compilers
would presumably produce debugging information using pure DWARF
constructs, so would not be impacted by this.

gdb/ChangeLog:

        * dwarf2read.c (need_gnat_info): Return nonzero if the cu's
        language is Ada.

Tested on x86_64-linux.
2018-01-21 23:23:34 -05:00
Yao Qi
4a17f7688f Make abbrev_table::abbrevs private
abbrev_table::abbrevs is only access within abbrev_table's methods, so
it can be private.  Add "m_" prefix.

gdb:

2018-01-18  Yao Qi  <yao.qi@linaro.org>

	* dwarf2read.c (abbrev_table) <abbrevs>: Rename it to
	m_abbrevs.
	(abbrev_table::add_abbrev): Update.
	(abbrev_table::lookup_abbrev): Update.
2018-01-18 15:29:31 +00:00
Tom Tromey
9e14690d06 Remove symbolp typedef
This removes the symbolp typedef from dwarf2read.c.  It is no longer
used.

2018-01-17  Tom Tromey  <tom@tromey.com>

	* dwarf2read.c (symbolp): Remove typedef.  Don't instantiate VEC.
2018-01-17 11:28:44 -07:00
Tom Tromey
50a820477b Remove objfile argument from add_dyn_prop
The objfile argument to add_dyn_prop is redundant, so this patch
removes it.

2018-01-17  Tom Tromey  <tom@tromey.com>

	* gdbtypes.h (add_dyn_prop): Remove objfile parameter.
	* gdbtypes.c (add_dyn_prop): Remove objfile parameter.
	(create_array_type_with_stride): Update.
	* dwarf2read.c (set_die_type): Update.
2018-01-17 11:28:44 -07:00
Tom Tromey
c89b44cdc5 Change dwarf2_cu::method_info to be a std::vector
This changes the type of dwarf2_cu::method_info and fixes up the uses.
In order to remove cleanups from process_full_comp_unit and
process_full_type_unit, psymtab_include_file_name also had to be
changed to avoid leaving dangling cleanups.

2018-01-17  Tom Tromey  <tom@tromey.com>

	* dwarf2read.c (delayed_method_info): Remove typedef.
	(dwarf2_cu::method_info): Now a std::vector.
	(add_to_method_list): Update.
	(free_delayed_list): Remove.
	(compute_delayed_physnames): Update.
	(process_full_comp_unit, process_full_type_unit): Clear the method
	list.  Remove cleanups.
	(psymtab_include_file_name): Add name_holder parameter.  Use
	unique_xmalloc_ptr.
	(dwarf_decode_lines): Update.
2018-01-17 11:28:44 -07:00
Simon Marchi
fcd3b13d80 Allocate dwarf2_cu with new
This changes dwarf2_cu to be allocated with new, and fixes up the
users.

2018-01-17  Tom Tromey  <tom@tromey.com>
	    Simon Marchi  <simon.marchi@ericsson.com>

	* dwarf2read.c (struct dwarf2_cu): Add constructor, destructor.
	(dwarf2_per_objfile::free_cached_comp_units)
	(init_tu_and_read_dwo_dies, init_cutu_and_read_dies)
	(init_cutu_and_read_dies_no_follow): Update.
	(dwarf2_cu::dwarf2_cu): Rename from init_one_comp_unit.
	(dwarf2_cu::~dwarf2_cu): New.
	(free_heap_comp_unit, free_stack_comp_unit): Remove.
	(age_cached_comp_units, free_one_cached_comp_unit): Update.
2018-01-17 11:28:44 -07:00
Tom Tromey
685af9cd22 Allocate abbrev_table with new
This changes dwarf2read.c to allocate abbrev tables using "new", and
then updates the users.

This version of the patch incorporates the changes that Simon
implemented.  These changes simplify the ownership rules for abbrev
tables.

2018-01-17  Tom Tromey  <tom@tromey.com>
	    Simon Marchi  <simon.marchi@ericsson.com>

	* dwarf2read.c (struct dwarf2_cu) <abbrev_table>: Remove.
	(struct die_reader_specs) <abbrev_table>: New member.
	(struct abbrev_table): Add constructor.
	<alloc_abbrev, add_abbrev, lookup_abbrev>: Declare.
	<abbrev_obstack>: Now an auto_obstack.
	(abbrev_table_up): New typedef.
	(init_cu_die_reader): Add abbrev_table parameter.
	(read_cutu_die_from_dwo): Remove abbrev_table_provided parameter.
	Add result_dwo_abbrev_table.
	(init_tu_and_read_dwo_dies, init_cutu_and_read_dies)
	(init_cutu_and_read_dies_no_follow, build_type_psymtabs_1):
	Update.
	(peek_die_abbrev): Take die_reader_specs, not dwarf_cu as
	parameter.
	(skip_children): Update.
	(abbrev_table::alloc_abbrev): Rename from
	abbrev_table_alloc_abbrev.
	(abbrev_table::add_abbrev): Rename from abbrev_table_add_abbrev.
	(abbrev_table::lookup_abbrev): Rename from
	abbrev_table_lookup_abbrev.
	(abbrev_table_read_table): Return abbrev_table_up.
	(abbrev_table_free, abbrev_table_free_cleanup)
	(dwarf2_read_abbrevs, dwarf2_free_abbrev_table): Remove.
	(load_partial_dies): Update.
2018-01-17 11:28:44 -07:00
Tom Tromey
5e2db402c8 Unify new_symbol and new_symbol_full
This patch unifies new_symbol with new_symbol_full, replacing a
wrapper function with a default parameter.

2018-01-17  Tom Tromey  <tom@tromey.com>

	* dwarf2read.c (dwarf2_compute_name): Update comment.
	(read_func_scope, read_variable): Update.
	(new_symbol): Remove.
	(new_symbol_full): Rename to new_symbol.
2018-01-17 11:28:44 -07:00
Pedro Alves
618daa933c language_get_symbol_name_matcher -> get_symbol_name_matcher
Rename language_get_symbol_name_matcher -> get_symbol_name_matcher,
since the function is no longer a straight "language method".

gdb/ChangeLog:
2018-01-10  Pedro Alves  <palves@redhat.com>

	* language.h (language_get_symbol_name_matcher): Rename ...
	(get_symbol_name_matcher): ... this.
	* language.c (language_get_symbol_name_matcher): Ditto.
	* dictionary.c, linespec.c, minsyms.c, psymtab.c, symtab.c: All
	callers adjusted.
2018-01-10 23:12:48 +00:00
Pedro Alves
c63d3e8d12 Ada: make verbatim matcher override other language matchers (PR gdb/22670)
A previous patch fixed verbatim matching in the lookup at the minimal
symbol level, but we should also be finding that same symbol through
the partial/full symtab search.

For example, this is what happens if we use "print" instead of
"break":

    (gdb) p <MixedCaseFunc>
    $1 = {<text variable, no debug info>} 0x4024dc <MixedCaseFunc>

Before the C++ wildmatching series, GDB knows that MixedCaseFunc is a
function without parameters, and the expression above means calling
it.  If you try it before having started the inferior, you'd get the
following (expected) error:

    (gdb) print  <MixedCaseFunc>
    You can't do that without a process to debug.

The main idea behind making the name matcher be determined by the
symbol's language is so that C++ (etc.) wildmatching in linespecs
works even if the current language is not C++, as e.g., when you step
through C or assembly code.

Ada's verbatim matching syntax however ("<...>") isn't quite the same.
It is more a property of the current language than of a particular
symbol's language.  We want to support this syntax when debugging an
Ada program, but it's reason of existence is to find non-Ada symbols.
This suggests going back to enabling it depending on current language
instead of language of the symbol being matched.

I'm not entirely happy with the "current_language" reference (though I
think that it's harmless).  I think we could try storing the current
language in the lookup_name_info object, and then convert a bunch of
functions more to pass around lookup_name_info objects instead of
"const char *" names.  I.e., build the lookup_name_info higher up.
I'm not sure about that, I'll have to think more about it.  Maybe
something different will be better.  Meanwhile, this gets us going.

I've extended the testcase to also exercise a no-debug-info function,
for extra coverage of the minsyms-only paths.

gdb/ChangeLog:
2018-01-10  Pedro Alves  <palves@redhat.com>

	PR gdb/22670
	* dwarf2read.c
	(gdb_index_symbol_name_matcher::gdb_index_symbol_name_matcher):
	Adjust to use language_get_symbol_name_matcher instead of
	language_defn::la_get_symbol_name_matcher.
	* language.c (language_get_symbol_name_matcher): If in Ada mode
	and the lookup name is a verbatim match, return Ada's matcher.
	* language.h (language_get_symbol_name_matcher): Adjust comment.
	(ada_lookup_name_info::verbatim_p):: New method.

gdb/testsuite/ChangeLog:
2018-01-10  Pedro Alves  <palves@redhat.com>

	PR gdb/22670
	* gdb.ada/bp_c_mixed_case.exp: Add intro comment.  Test printing C
	functions too.  Test setting breakpoints and printing C functions
	with no debug info too.
	* gdb.ada/bp_c_mixed_case/qux.c: New file.
2018-01-10 20:47:37 +00:00
Xavier Roirand
b1dc1806fa Fix breakpoint add on inlined function using function name.
Using this Ada example:

  package B is
    procedure Read_Small with Inline_Always;
  end B;

  package body B is
    Total : Natural := 0;
    procedure Read_Small is
    begin
      Total := Total + 1;
    end Read_Small;
  end B;

and

  with B;

  procedure M is
  begin
    B.Read_Small;
  end M;

% gnatmake -g -O0 -m m.adb -cargs -gnatn
% gdb m

Inserting a breakpoint on Read_Small inlined function does not work:

(gdb) b read_small
Breakpoint 1 at 0x40250e: file b.adb, line 5.
(gdb) info b
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x000000000040250e in b.doit at b.adb:5
(gdb)

In this exemple we should have two breakpoints set, one in package B and
the other one in the inlined instance inside procedure M), like below:

(gdb) b read_small
Breakpoint 1 at 0x40250e: b.adb:5. (2 locations)
(gdb) info b
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   <MULTIPLE>
1.1                         y     0x000000000040250e in b.doit at b.adb:5
1.2                         y     0x0000000000402540 in m at b.adb:5
(gdb)

Looking at the DWARF info for inlined instance of Read_Small:

<1><1526>: Abbrev Number: 2 (DW_TAG_subprogram)
    <1527>   DW_AT_name        : ([...], offset: 0x1e82): b__read_small
    <152b>   DW_AT_decl_file   : 2
    <152c>   DW_AT_decl_line   : 3
    <152d>   DW_AT_inline      : 3      (declared as inline and inlined)
[...]
 <2><1547>: Abbrev Number: 4 (DW_TAG_inlined_subroutine)
    <1548>   DW_AT_abstract_origin: <0x1526>
    <154c>   DW_AT_low_pc      : 0x402552
    <1554>   DW_AT_high_pc     : 0x2b
    <155c>   DW_AT_call_file   : 1
    <155d>   DW_AT_call_line   : 5
 <2><155e>: Abbrev Number: 0

During the parsing of DWARF info in order to produce partial DIE linked
list, the DW_TAG_inlined_subroutine were skipped thus not present in the
final partial dies.
Taking DW_TAG_inlined_subroutine in account during the parsing process
fixes the problem.

gdb/ChangeLog:

        * dwarf2read.c (scan_partial_symbols, add_partial_symbol)
        (add_partial_subprogram, load_partial_dies): Add
        DW_TAG_inlined_subroutine handling.

gdb/testsuite/ChangeLog:

        * gdb.ada/bp_inlined_func: New testcase.
2018-01-09 10:02:51 +01:00
Simon Marchi
518817b361 Remove dwarf2_cu::dwarf2_per_objfile
This patch removes the dwarf2_per_objfile field of dwarf2_cu.  It is
redundant, since we can access dwarf2_per_objfile through
dwarf2_per_objfile, which is guaranteed to be set.

gdb/ChangeLog:

	* dwarf2read.c (struct dwarf2_cu) <dwarf2_per_objfile>: Remove.
	(dw2_get_file_names_reader): Adjust.
	(lookup_dwo_signatured_type): Adjust.
	(lookup_dwp_signatured_type): Adjust.
	(lookup_signatured_type): Adjust.
	(create_type_unit_group): Adjust.
	(get_type_unit_group): Adjust.
	(process_psymtab_comp_unit_reader): Adjust.
	(build_type_psymtabs_reader): Adjust.
	(scan_partial_symbols): Adjust.
	(add_partial_symbol): Adjust.
	(add_partial_subprogram): Adjust.
	(peek_die_abbrev): Adjust.
	(fixup_go_packaging): Adjust.
	(process_imported_unit_die): Adjust.
	(dwarf2_compute_name): Adjust.
	(dwarf2_physname): Adjust.
	(read_import_statement): Adjust.
	(handle_DW_AT_stmt_list): Adjust.
	(read_file_scope): Adjust.
	(read_func_scope): Adjust.
	(read_lexical_block_scope): Adjust.
	(read_call_site_scope): Adjust.
	(read_variable): Adjust.
	(dwarf2_rnglists_process): Adjust.
	(dwarf2_ranges_process): Adjust.
	(dwarf2_ranges_read): Adjust.
	(dwarf2_get_pc_bounds): Adjust.
	(dwarf2_record_block_ranges): Adjust.
	(dwarf2_add_field): Adjust.
	(dwarf2_add_member_fn): Adjust.
	(read_structure_type): Adjust.
	(process_structure_scope): Adjust.
	(read_enumeration_type): Adjust.
	(read_array_type): Adjust.
	(mark_common_block_symbol_computed): Adjust.
	(read_common_block): Adjust.
	(read_namespace_type): Adjust.
	(read_namespace): Adjust.
	(read_module_type): Adjust.
	(read_tag_pointer_type): Adjust.
	(read_tag_ptr_to_member_type): Adjust.
	(read_tag_string_type): Adjust.
	(read_subroutine_type): Adjust.
	(read_typedef): Adjust.
	(read_base_type): Adjust.
	(attr_to_dynamic_prop): Adjust.
	(read_subrange_type): Adjust.
	(read_unspecified_type): Adjust.
	(dwarf2_read_abbrevs): Adjust.
	(load_partial_dies): Adjust.
	(read_partial_die): Adjust.
	(find_partial_die): Adjust.
	(guess_partial_die_structure_name): Adjust.
	(fixup_partial_die): Adjust.
	(read_attribute_value): Adjust.
	(read_addr_index): Adjust.
	(read_addr_index_from_leb128): Adjust.
	(read_str_index): Adjust.
	(dwarf2_string_attr): Adjust.
	(get_debug_line_section): Adjust.
	(dwarf_decode_line_header): Adjust.
	(lnp_state_machine::check_line_address): Adjust.
	(dwarf_decode_lines_1): Adjust.
	(dwarf_decode_lines): Adjust.
	(dwarf2_start_symtab): Adjust.
	(var_decode_location): Adjust.
	(new_symbol_full): Adjust.
	(dwarf2_const_value_data): Adjust.
	(dwarf2_const_value_attr): Adjust.
	(dwarf2_const_value): Adjust.
	(die_type): Adjust.
	(die_containing_type): Adjust.
	(build_error_marker_type): Adjust.
	(lookup_die_type): Adjust.
	(guess_full_die_structure_name): Adjust.
	(anonymous_struct_prefix): Adjust.
	(determine_prefix): Adjust.
	(dwarf2_name): Adjust.
	(follow_die_ref_or_sig): Adjust.
	(follow_die_offset): Adjust.
	(follow_die_ref): Adjust.
	(follow_die_sig_1): Adjust.
	(follow_die_sig): Adjust.
	(get_signatured_type): Adjust.
	(get_DW_AT_signature_type): Adjust.
	(decode_locdesc): Adjust.
	(dwarf_decode_macros): Adjust.
	(cu_debug_loc_section): Adjust.
	(fill_in_loclist_baton): Adjust.
	(dwarf2_symbol_mark_computed): Adjust.
	(init_one_comp_unit): Don't assign
	dwarf2_cu::dwarf2_per_objfile.
	(set_die_type): Adjust.
2018-01-07 11:22:46 -05:00
Simon Marchi
ed2dc618b3 Remove dwarf2_per_objfile global
This patch removes the global variable dwarf2_per_objfile.  This global
variable is set at the various entry points of dwarf2read.c (using
dw2_setup), and is referred to throughout the file.  Instead of passing
data between functions in global variables like this one, it would be
better if the functions that depend on it either received it as argument
or got it from the existing arguments they receive.  For example, a
function receiving a reference to a dwarf2_per_cu_data can access it
from dwarf2_per_cu_data::dwarf2_per_objfile.

This patch has been tested on the buildbot.

gdb/ChangeLog:

	* dwarf2read.c (struct mapped_debug_names): Add constructor.
	<dwarf2_per_objfile>: New field.
	(dwarf2_per_objfile): Remove global.
	(get_dwarf2_per_objfile): New function.
	(set_dwarf2_per_objfile): New function.
	(dwarf2_build_psymtabs_hard): Change objfile parameter to
	dwarf2_per_objfile.
	(abbrev_table_read_table): Add dwarf2_per_objfile parameter.
	(read_abbrev_offset): Likewise.
	(read_indirect_string): Likewise.
	(read_indirect_line_string): Likewise.
	(read_indirect_string_at_offset): Likewise.
	(read_indirect_string_from_dwz): Likewise.
	(dwarf2_find_containing_comp_unit): Change objfile parameter to
	dwarf2_per_objfile.
	(age_cached_comp_units): Add dwarf2_per_objfile parameter.
	(create_all_comp_units): Change objfile parameter to
	dwarf2_per_objfile.
	(create_all_type_units): Likewise.
	(process_queue): Add dwarf2_per_objfile parameter.
	(read_and_check_comp_unit_head): Likewise.
	(lookup_dwo_unit_in_dwp): Likewise.
	(get_dwp_file): Likewise.
	(process_cu_includes): Likewise.
	(struct free_dwo_file_cleanup_data): New struct.
	(dwarf2_has_info): Use get_dwarf2_per_objfile and
	set_dwarf2_per_objfile.
	(dwarf2_get_dwz_file): Add dwarf2_per_objfile parameter.
	(dw2_do_instantiate_symtab): Get dwarf2_per_objfile from
	context, adjust calls.
	(dw2_instantiate_symtab): Likewise.
	(dw2_get_cutu): Add dwarf2_per_objfile parameter.
	(dw2_get_cu): Likewise.
	(create_cu_from_index_list): Change objfile parameter to
	dwarf2_per_objfile.
	(create_cus_from_index_list): Get dwarf2_per_objfile from
	context, adjust calls.
	(create_cus_from_index): Likewise.
	(create_signatured_type_table_from_index): Change objfile
	parameter to dwarf2_per_objfile.
	(create_signatured_type_table_from_debug_names): Change objfile
	parameter to dwarf2_per_objfile.
	(create_addrmap_from_index): Likewise.
	(create_addrmap_from_aranges): Likewise.
	(dwarf2_read_index): Use get_dwarf2_per_objfile, adjust calls.
	(dw2_setup): Remove.
	(dw2_get_file_names_reader): Get dwarf2_per_objfile from
	context.
	(dw2_find_last_source_symtab): Get dwarf2_per_objfile using
	get_dwarf2_per_objfile.
	(dw2_forget_cached_source_info): Likewise.
	(dw2_map_symtabs_matching_filename): Likewise.
	(struct dw2_symtab_iterator) <index>: Remove.
	<dwarf2_per_objfile>: New field.
	(dw2_symtab_iter_init): Replace index parameter with
	dwarf2_per_objfile.
	(dw2_symtab_iter_next): Use dwarf2_per_objfile from iter.
	(dw2_lookup_symbol): Use get_dwarf2_per_objfile and adjust.
	(dw2_print_stats): Likewise.
	(dw2_dump): Likewise.
	(dw2_expand_symtabs_for_function): Likewise.
	(dw2_expand_all_symtabs): Likewise.
	(dw2_expand_symtabs_with_fullname): Likewise.
	(dw2_expand_marked_cus): Replace index and objfile parameters
	with dwarf2_per_objfile.
	(dw_expand_symtabs_matching_file_matcher): Add
	dwarf2_per_objfile parameter and adjust calls.
	(dw2_expand_symtabs_matching): Use get_dwarf2_per_objfile and
	adjust calls.
	(dw2_find_pc_sect_compunit_symtab): Don't call dw2_setup.
	(dw2_map_symbol_filenames): Use get_dwarf2_per_objfile and
	adjust calls.
	(create_cus_from_debug_names_list): Replace objfile parameter
	with dwarf2_per_objfile and adjust calls.
	(create_cus_from_debug_names): Likewise.
	(dwarf2_read_debug_names): Likewise.
	(mapped_debug_names::namei_to_name): Adjust call.
	(dw2_debug_names_iterator::next): Likewise.
	(dw2_debug_names_iterator::find_vec_in_debug_names): Likewise.
	(dw2_debug_names_lookup_symbol): Use get_dwarf2_per_objfile.
	(dw2_debug_names_dump): Likewise.
	(dw2_debug_names_expand_symtabs_for_function): Likewise.
	(dw2_debug_names_expand_symtabs_matching): Likewise.
	(dwarf2_initialize_objfile): Likewise.
	(dwarf2_build_psymtabs): Likewise.
	(get_abbrev_section_for_cu): Get dwarf2_per_objfile from
	this_cu.
	(error_check_comp_unit_head): Add dwarf2_per_objfile parameter.
	(read_and_check_comp_unit_head): Likewise.
	(read_abbrev_offset): Likewise.
	(create_debug_type_hash_table): Likewise.
	(create_debug_types_hash_table): Likewise.
	(create_all_type_units): Replace objfile parameter with
	dwarf2_per_objfile.
	(add_type_unit): Add dwarf2_per_objfile parameter.
	(fill_in_sig_entry_from_dwo_entry): Replace objfile parameter
	with dwarf2_per_objfile.
	(lookup_dwo_signatured_type): Get dwarf2_per_objfile from cu.
	(lookup_dwp_signatured_type): Likewise.
	(lookup_signatured_type): Likewise.
	(read_cutu_die_from_dwo): Likewise.
	(init_tu_and_read_dwo_dies): Likewise.
	(init_cutu_and_read_dies): Likewise.
	(init_cutu_and_read_dies_no_follow): Likewise.
	(allocate_type_unit_groups_table): Add objfile parameter.
	(create_type_unit_group): Use dwarf2_per_objfile from cu.
	(get_type_unit_group): Likewise.
	(process_psymtab_comp_unit): Update call.
	(build_type_psymtabs_reader): Use dwarf2_per_objfile from cu.
	(build_type_psymtabs_1): Add dwarf2_per_objfile parameter.
	(print_tu_stats): Likewise.
	(build_type_psymtab_dependencies): Use dwarf2_per_objfile passed
	in void* parameter.
	(build_type_psymtabs): Change objfile parameter to
	dwarf2_per_objfile.
	(process_skeletonless_type_unit): Use dwarf2_per_objfile
	passed in void* parameter.
	(process_skeletonless_type_units): Change objfile parameter to
	dwarf2_per_objfile.
	(set_partial_user): Likewise.
	(dwarf2_build_psymtabs_hard): Likewise.
	(read_comp_units_from_section): Likewise.
	(create_all_comp_units): Likewise.
	(scan_partial_symbols): Update calls.
	(add_partial_symbol): Likewise.
	(dwarf2_read_symtab): Use get_dwarf2_per_objfile.
	(maybe_queue_comp_unit): Use dwarf2_read_symtab from cu.
	(process_queue): Add dwarf2_per_objfile parameter.
	(get_compunit_symtab): Use dwarf2_per_objfile from cu.
	(compute_compunit_symtab_includes): Likewise.
	(process_cu_includes): Add dwarf2_per_objfile parameter.
	(process_full_comp_unit): Use dwarf2_per_objfile from cu.
	(process_full_type_unit): Likewise.
	(process_imported_unit_die): Update call.
	(handle_DW_AT_stmt_list): Use dwarf2_per_objfile from cu.
	(read_file_scope): Likewise.
	(allocate_dwo_file_hash_table): Add objfile parameter.
	(lookup_dwo_file_slot): Add dwarf2_per_objfile parameter.
	(create_cus_hash_table): Likewise.
	(create_dwp_hash_table): Likewise.
	(create_dwo_unit_in_dwp_v1): Likewise.
	(create_dwp_v2_section): Likewise.
	(create_dwo_unit_in_dwp_v2): Likewise.
	(lookup_dwo_unit_in_dwp): Likewise.
	(try_open_dwop_file): Likewise.
	(open_dwo_file): Likewise. Use dwarf2_per_objfile from cu.
	(open_and_init_dwo_file): Use dwarf2_per_objfile from cu, update
	cleanup to include a reference to dwarf2_per_objfile.
	(open_dwp_file): Add dwarf2_per_objfile parameter.
	(open_and_init_dwp_file): Likewise.
	(get_dwp_file): Likewise.
	(lookup_dwo_cutu): Use dwarf2_per_objfile from cu.
	(queue_and_load_all_dwo_tus): Update call.
	(free_dwo_file_cleanup): Use dwarf2_per_objfile from cleanup
	data.
	(dwarf2_rnglists_process): Use dwarf2_per_objfile from cu.
	(dwarf2_ranges_process): Likewise.
	(dwarf2_get_pc_bounds): Likewise.
	(mark_common_block_symbol_computed): Likewise.
	(abbrev_table_read_table): Add dwarf2_per_objfile parameter.
	(dwarf2_read_abbrevs): Update call.
	(read_partial_die): Use dwarf2_per_objfile from cu.
	(find_partial_die): Likewise.
	(fixup_partial_die): Likewise.
	(read_attribute_value): Likewise.
	(read_indirect_string_at_offset_from): Add objfile parameter.
	(read_indirect_string_at_offset): Add dwarf2_per_objfile
	parameter.
	(read_indirect_string_from_dwz): Add objfile parameter.
	(read_indirect_string): Add objfile parameter.
	(read_addr_index_1): Add dwarf2_per_objfile parameter.
	(read_addr_index): Use dwarf2_per_objfile from cu.
	(dwarf2_read_addr_index): Use dwarf2_per_objfile from cu, don't
	call dw2_setup.
	(read_str_index): Use dwarf2_per_objfile from cu.
	(get_debug_line_section): Likewise.
	(read_formatted_entries): Add dwarf2_per_objfile parameter.
	(dwarf_decode_line_header): Use dwarf2_per_objfile from cu.
	(new_symbol_full): Use dwarf2_per_objfile from cu.
	(build_error_marker_type): Likewise.
	(lookup_die_type): Likewise.
	(determine_prefix): Likewise.
	(follow_die_offset): Likewise.
	(dwarf2_fetch_die_loc_sect_off): Use get_dwarf2_per_objfile.
	(dwarf2_fetch_constant_bytes): Don't call dw2_setup.
	(dwarf2_fetch_die_type_sect_off): Likewise.
	(dwarf2_get_die_type): Likewise.
	(follow_die_sig_1): Use dwarf2_per_objfile from cu.
	(get_signatured_type): Likewise.
	(get_DW_AT_signature_type): Likewise.
	(dwarf_decode_macro_bytes): Add dwarf2_per_objfile parameter.
	(dwarf_decode_macros): Use dwarf2_per_objfile from cu.
	(cu_debug_loc_section): Likewise.
	(fill_in_loclist_baton): Likewise.
	(dwarf2_symbol_mark_computed): Likewise.
	(dwarf2_find_containing_comp_unit): Change objfile parameter to
	dwarf2_per_objfile.
	(free_cached_comp_units): Use dwarf2_per_objfile passed in void*
	parameter.
	(age_cached_comp_units): Add dwarf2_per_objfile parameter.
	(free_one_cached_comp_unit): Use dwarf2_per_objfile from cu.
	(dwarf2_free_objfile): Use get_dwarf2_per_objfile.
	(set_die_type): Use dwarf2_free_objfile from cu.
	(get_die_type_at_offset): Likewise.
	(dwarf2_per_objfile_free): Don't assign global variable.
	(debug_names) <constructor>: Add dwarf2_per_objfile
	parameter, update m_debugstrlookup construction.
	(debug_names::debug_str_lookup): Add dwarf2_per_objfile
	parameter.
	<m_dwarf2_per_objfile>: New field.
	<lookup>: Use m_dwarf2_per_objfile.
	(check_dwarf64_offsets): Add dwarf2_per_objfile parameter.
	(psyms_seen_size): Likewise.
	(write_gdbindex): Replace objfile parameter with
	dwarf2_per_objfile.
	(write_debug_names): Likewise.
	(write_psymtabs_to_index): Likewise.
	(save_gdb_index_command): Use get_dwarf2_per_objfile, update
	calls.
2018-01-07 11:22:46 -05:00
Simon Marchi
e3b9454612 Replace objfile field in dwarf2_cu and dwarf2_per_cu_data with dwarf2_per_objfile
The next patch aims to remove the dwarf2_per_objfile global.  In many
functions, we need to find a way to get a reference to the current
dwarf2_per_objfile through the objects passed in parameters.  Often, we have
access to a dwarf2_cu or a dwarf2_per_cu_data.  These objects have a reference
to the objfile, through which we can get the dwarf2_per_objfile:

  dwarf2_per_objfile = ((struct dwarf2_per_objfile *)
		        objfile_data (objfile, dwarf2_objfile_data_key));

However, this is a bit cumbersome to do all over the place.  It would be
more logical if the dwarf2_cu and dwarf2_per_cu_data had a reference to
their dwarf2_per_objfile, which would then have a reference to the
objfile.  It would be more in line with the object hierarchy, where
dwarf2_per_objfile owns the dwarf2_per_cu_data instances.  We could
even remove the reference dwarf2_cu has to dwarf2_per_objfile, since we
can access dwarf2_per_objfile through dwarf2_cu::per_cu.

In a graphical way, references would look like this after the current
patch:

  objfile <--- dwarf2_per_objfile <--- dwarf2_per_cu_data
                                    |      ^
				    |      |
                                    `- dwarf2_cu

This patch has been tested on the buildbot.

gdb/ChangeLog:

	* dwarf2read.c (struct dwarf2_cu) <objfile>: Remove.
	<dwarf2_per_objfile>: New field.
	(struct dwarf2_per_cu_data) <objfile>: Remove.
	<dwarf2_per_objfile>: New field.
	(create_cu_from_index_list): Assign dwarf2_per_objfile instead
	of objfile.
	(create_signatured_type_table_from_index): Likewise.
	(create_debug_type_hash_table): Likewise.
	(fill_in_sig_entry_from_dwo_entry): Likewise.
	(lookup_dwo_unit): Access objfile through dwarf2_per_objfile.
	(create_type_unit_group): Assign dwarf2_per_objfile instead of
	objfile.
	(create_partial_symtab): Access objfile through
	dwarf2_per_objfile.
	(process_psymtab_comp_unit_reader): Likewise.
	(read_comp_units_from_section): Likewise.
	(scan_partial_symbols): Likewise.
	(add_partial_symbol): Likewise.
	(add_partial_subprogram): Likewise.
	(peek_die_abbrev): Likewise.
	(fixup_go_packaging): Likewise.
	(process_full_comp_unit): Likewise.
	(process_full_type_unit): Likewise.
	(process_imported_unit_die): Likewise.
	(dwarf2_compute_name): Likewise.
	(dwarf2_physname): Likewise.
	(read_import_statement): Likewise.
	(create_cus_hash_table): Assign dwarf2_physname instead of
	objfile.
	(read_func_scope): Access objfile through dwarf2_per_objfile.
	(read_lexical_block_scope): Likewise.
	(read_call_site_scope): Likewise.
	(read_variable): Likewise.
	(dwarf2_rnglists_process): Likewise.
	(dwarf2_ranges_process): Likewise.
	(dwarf2_ranges_read): Likewise.
	(dwarf2_record_block_ranges): Likewise.
	(dwarf2_add_field): Likewise.
	(dwarf2_add_member_fn): Likewise.
	(read_structure_type): Likewise.
	(process_structure_scope): Likewise.
	(read_enumeration_type): Likewise.
	(read_array_type): Likewise.
	(read_common_block): Likewise.
	(read_namespace_type): Likewise.
	(read_namespace): Likewise.
	(read_module_type): Likewise.
	(read_tag_pointer_type): Likewise.
	(read_tag_ptr_to_member_type): Likewise.
	(read_tag_string_type): Likewise.
	(read_subroutine_type): Likewise.
	(read_typedef): Likewise.
	(read_base_type): Likewise.
	(attr_to_dynamic_prop): Likewise.
	(read_subrange_type): Likewise.
	(read_unspecified_type): Likewise.
	(load_partial_dies): Likewise.
	(read_partial_die): Likewise.
	(find_partial_die): Likewise.
	(guess_partial_die_structure_name): Likewise.
	(fixup_partial_die): Likewise.
	(read_attribute_value): Likewise.
	(read_addr_index_from_leb128): Likewise.
	(dwarf2_read_addr_index): Likewise.
	(dwarf2_string_attr): Likewise.
	(lnp_state_machine::check_line_address): Likewise.
	(dwarf_decode_lines_1): Likewise.
	(dwarf_decode_lines): Likewise.
	(dwarf2_start_symtab): Likewise.
	(var_decode_location): Likewise.
	(new_symbol_full): Likewise.
	(dwarf2_const_value_data): Likewise.
	(dwarf2_const_value_attr): Likewise.
	(dwarf2_const_value): Likewise.
	(die_type): Likewise.
	(die_containing_type): Likewise.
	(lookup_die_type): Likewise.
	(guess_full_die_structure_name): Likewise.
	(anonymous_struct_prefix): Likewise.
	(dwarf2_name): Likewise.
	(follow_die_ref_or_sig): Likewise.
	(follow_die_offset): Likewise.
	(follow_die_ref): Likewise.
	(dwarf2_fetch_die_loc_sect_off): Likewise.
	(dwarf2_fetch_constant_bytes): Likewise.
	(dwarf2_fetch_die_type_sect_off): Likewise.
	(dwarf2_get_die_type): Likewise.
	(follow_die_sig): Likewise.
	(decode_locdesc): Likewise.
	(dwarf2_per_cu_objfile): Likewise.
	(dwarf2_per_cu_text_offset): Likewise.
	(init_one_comp_unit): Assign dwarf2_per_objfile instead of
	objfile.
	(set_die_type): Access objfile through
	dwarf2_per_objfile.
2018-01-07 11:22:45 -05:00
Joel Brobecker
a405673cc5 Add support for dynamic DW_AT_byte_stride.
This patch adds support for DW_AT_byte_stride, using Ada as one
example of where this would be useful. However, the implementation
is language-agnostic.

Consider the following Ada code:

   procedure Nested (L, U : Integer) is
      subtype Small_Type is Integer range L .. U;
      type Record_Type (I : Small_Type := L) 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"));

      procedure Discard (R : Record_Type) is
      begin
         null;
      end Discard;

   begin
      Discard (A1 (1));  -- STOP
   end;

It defines an array A1 of Record_Type, which is a variant record
type whose maximum size actually depends on the value of the
parameters passed when calling Nested. As a result, the stride
of the array A1 cannot be known statically, which leads the compiler
to generate a dynamic DW_AT_byte_stride attribute for our type.
Here is what the debugging info looks like with GNAT:

        .uleb128 0x10   # (DIE (0x14e) DW_TAG_array_type)
        .long   .LASF17 # DW_AT_name: "foo__nested__T18b"
        .long   0x141   # DW_AT_byte_stride
        .long   0xdc    # DW_AT_type
        .uleb128 0x11   # (DIE (0x15f) DW_TAG_subrange_type)
        .long   0x166   # DW_AT_type
        .byte   0x3     # DW_AT_upper_bound
        .byte   0       # end of children of DIE 0x14e

There DW_AT_byte_stride is a reference to a local (internal)
variable:

        .uleb128 0x9    # (DIE (0x141) DW_TAG_variable)
        .long   .LASF6  # DW_AT_name: "foo__nested__T18b___PAD___XVZ"

This patch enhances GDB to handle this dynamic byte stride attribute
by first adding a new dynamic_prop_node_kind (DYN_PROP_BYTE_STRIDE)
to store the array dynamic stride info (when dynamic). It then enhances
the dynamic type resolver to handle this dynamic property.

Before applying this patch, trying to print the value of some of
A1's elements after having stopped at the "STOP" comment does not
work. For instance:

    (gdb) p a1(2)
    Cannot access memory at address 0x80000268dec0

With this patch applied, GDB now prints the value of all 3 elements
correctly:

    (gdb) print A1(1)
    $1 = (i => 0, s => "")
    (gdb) print A1(2)
    $2 = (i => 1, s => "A")
    (gdb) print A1(3)
    $3 = (i => 2, s => "AB")

gdb/ChangeLog:

        * gdbtypes.h (enum dynamic_prop_node_kind) <DYN_PROP_BYTE_STRIDE>:
        New enum value.
        (create_array_type_with_stride): Add byte_stride_prop parameter.
        * gdbtypes.c (create_array_type_with_stride) <byte_stride_prop>:
        New parameter.  Update all callers in this file.
        (array_type_has_dynamic_stride): New function.
        (is_dynamic_type_internal, resolve_dynamic_array): Add handling
        of arrays with dynamic byte strides.
        * dwarf2read.c (read_array_type): Add support for dynamic
        DW_AT_byte_stride attributes.

gdb/testsuite/ChangeLog:

        * gdb.ada/dyn_stride: New testcase.

Tested on x86_64-linux.
2018-01-01 22:50:13 -05:00
Joel Brobecker
74a2f8ffb8 treat Ada DW_TAG_unspecified_type DIEs as stub types
Consider the gdb.ada/taft_type.exp testcase, which exercises
the situation where a variable is defined using a type which
is a pointer to an incomplete type, with the actual type
definition being provided by another unit. Up to now, the
strategy used by GNAT when generating the DWARF debugging info
was to produce a incomplete DW_TAG_enumeration_type DIE with
a DW_AT_declaration flag attached to it:

        .uleb128 0x4    # (DIE (0x3e) DW_TAG_enumeration_type)
        .long   .LASF4  # DW_AT_name: "pck__empty"
                        # DW_AT_declaration

However, a more standard way for the compiler to describe
this kind of type is to use the DW_TAG_unspecified_type tag.
When the compiler is enhanced to do so, we'll need to treat
such types as stubs -- we only do so with types from Ada units,
however, as the meaning of this TAG is intentionally left
permissive and language-specific by the DWARF standard.

Without this patch, running the testcase above with an enhanced
compiler now yields:

    (gdb) print w.e.all
    Attempt to dereference a generic pointer.
    FAIL: gdb.ada/taft_type.exp: print w.e.all

gdb/ChangeLog:

	* dwarf2read.c (read_unspecified_type): Treat
        DW_TAG_enumeration_type DIEs from Ada units as stubs.

Tested on x86_64-linux, fixes the FAIL in gdb.ada/taft_type.exp above.
2018-01-01 22:41:36 -05:00
Joel Brobecker
e2882c8578 Update copyright year range in all GDB files
gdb/ChangeLog:

        Update copyright year range in all GDB files
2018-01-02 07:38:06 +04:00
Simon Marchi
132448f835 dwarf2read: Silence -Wenum-compare-switch warning
Compiling with Clang 6 gives:

/home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:24385:14: error: comparison of two values with different enumeration types in switch statement ('enum dwarf_macro_record_type' and 'dwarf_macinfo_record_type') [-Werror,-Wenum-compare-switch]
        case DW_MACINFO_vendor_ext:
             ^~~~~~~~~~~~~~~~~~~~~
/home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:24561:7: error: comparison of two values with different enumeration types in switch statement ('enum dwarf_macro_record_type' and 'dwarf_macinfo_record_type') [-Werror,-Wenum-compare-switch]
        case DW_MACINFO_vendor_ext:
             ^~~~~~~~~~~~~~~~~~~~~

This code uses the two enum types on purpose, because it handles both
.debug_macro and .debug_macinfo sections.  Add some pragmas to disable
the warning in these specific cases.

gdb/ChangeLog:

	* dwarf2read.c (dwarf_decode_macro_bytes): Ignore
	-Wenum-compare-switch warning.
	(dwarf_decode_macros): Likewise.
2017-12-30 21:24:42 -05:00
Simon Marchi
fc898b42e3 Make mapped_debug_names and mapped_index final
When compiling with Clang 6, I see these warnings:

/home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:25421:5: error: destructor called on non-final 'mapped_index' that has virtual functions but non-virtual destructor [-Werror,-Wdelete-non-virtual-dtor]
    data->index_table->~mapped_index ();
    ^
In file included from /home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:31:
In file included from /home/emaisin/src/binutils-gdb/gdb/defs.h:28:
In file included from /home/emaisin/src/binutils-gdb/gdb/common/common-defs.h:92:
In file included from /home/emaisin/src/binutils-gdb/gdb/common/gdb_unique_ptr.h:23:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/memory:81:
/usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/unique_ptr.h:76:2: error: delete called on non-final 'mapped_debug_names' that has virtual functions but non-virtual destructor [-Werror,-Wdelete-non-virtual-dtor]
        delete __ptr;
        ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/bits/unique_ptr.h:236:4: note: in instantiation of member function 'std::default_delete<mapped_debug_names>::operator()' requested here
          get_deleter()(__ptr);
          ^
/home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:2374:21: note: in instantiation of member function 'std::unique_ptr<mapped_debug_names, std::default_delete<mapped_debug_names> >::~unique_ptr' requested here
dwarf2_per_objfile::dwarf2_per_objfile (struct objfile *objfile_,
                    ^

This patch silences these warnings by making the classes final.

gdb/ChangeLog:

	* dwarf2read.c (struct mapped_debug_names): Make final.
	(struct mapped_index): Make final.
2017-12-30 00:10:17 -05:00
Jan Kratochvil
8af5c486ea DWARF-5 .debug_names DW_IDX_type_unit fix
The .debug_names completely misses its support as it did not even produce
DW_IDX_type_unit.

gdb/ChangeLog
2017-12-14  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* dwarf2read.c (dw2_debug_names_iterator::next): Support
	DW_IDX_type_unit.
	(debug_names::dwarf5_offset_size, unit_kind): New.
	(debug_names::insert): Add parameter kind.
	(debug_names::build): Support DW_IDX_type_unit.
	(debug_names::recursively_write_psymbols): Update
	(debug_names::write_psymbols caller.
	(debug_names::write_one_signatured_type_data)
	(debug_names::write_one_signatured_type): New.
	(debug_names::index_key, debug_names::symbol_value)
	(debug_names::write_psymbols): Add kind.
	(debug_names::write_one_signatured_type): New.
	(write_debug_names): Move dwarf5_offset_size to debug_names.
	Use debug_names::write_one_signatured_type for type units.
2017-12-14 10:02:09 +01:00
Pedro Alves
3c0aa29aab Unbreak build for non-ELF ports
As reported at
<https://sourceware.org/ml/gdb-patches/2017-12/msg00229.html>, this
commit:

~~~~
 commit abccd1e7b7
 Author:     Jan Kratochvil <jan.kratochvil@redhat.com>
 AuthorDate: Fri Dec 8 22:44:11 2017 +0000

     Change dwarf2_initialize_objfile's return value

     dwarf2_initialize_objfile was returning boolean whether it is psymtabs
     or .gdb_index while now it needs to return also whether it is
     .debug_names.
~~~~

breaks non-ELF-target builds:

 dwarf2read.o: In function `dwarf2_initialize_objfile(objfile*)':
 /home/yao.qi/SourceCode/gnu/binutils-gdb/gdb/dwarf2read.c:6486:
 undefined reference to `elf_sym_fns_gdb_index'
 /home/yao.qi/SourceCode/gnu/binutils-gdb/gdb/dwarf2read.c:6490:
 undefined reference to `elf_sym_fns_debug_names'
 /home/yao.qi/SourceCode/gnu/binutils-gdb/gdb/dwarf2read.c:6495:
 undefined reference to `elf_sym_fns_lazy_psyms'
 collect2: error: ld returned 1 exit status
	 Makefile:1920: recipe for target 'gdb' failed

because gdb/elfread.c is not included in the gdb build unless bfd also
includes elf support.

Fix this by reverting the patch mentioned above and at the same time
re-adding .debug_names support by adding a new output parameter to
dwarf2_initialize_objfile to indicate the index variant in use.  We
can reuse the new dw_index_kind enum in dwarf2read.c for that.

gdb/ChangeLog:
2017-12-11  Pedro Alves  <palves@redhat.com>

	* defs.h (elf_sym_fns_lazy_psyms, elf_sym_fns_gdb_index)
	(elf_sym_fns_debug_names): Move to elfread.c.
	* dwarf2read.c (dwarf2_initialize_objfile): Return a boolean
	instead of a sym_fns and add 'index_kind' output parameter.  Fill
	the latter in with the index variant kind if using an index.
	(enum dw_index_kind): Moved to symfile.h.
	* elfread.c (elf_sym_fns_gdb_index, elf_sym_fns_debug_names)
	(elf_sym_fns_lazy_psyms): Move from defs.h.
	(elf_symfile_read): Adjust to new dwarf2_initialize_objfile
	interface.
	* symfile.h (enum class dw_index_kind): New, moved from
	dwarf2read.c.
	(dwarf2_initialize_objfile): Change prototype.
2017-12-11 14:41:32 +00:00
Pedro Alves
a3c5fafd2e dwarf2read.c: Rewrite/simplify mock_mapped_index
Now that dw2_expand_symtabs_matching_symbol works with the abstract
mapped_index_base, we can make mock_mapped_index inherit
mapped_index_base too instead of having it pretend to be a real
.gdb_index table.

gdb/ChangeLog:
2017-12-08  Pedro Alves  <palves@redhat.com>

	* dwarf2read.c (mock_mapped_index): Reimplement as an extension of
	mapped_index_base.
	(check_match): Adjust to use mock_index directly.
	(check_find_bounds_finds)
	(test_mapped_index_find_name_component_bounds): Adjust to work
	with a mapped_index_base.
2017-12-08 23:38:41 +00:00
Pedro Alves
44ed8f3ed0 Support wildmatching in .debug_names too.
dw2_debug_names_expand_symtabs_matching currently doesn't support
symbol_name_match_type::WILD, it always matches symbol names fully.

The .gdb_index code supports via dw2_expand_symtabs_matching_symbol,
which builds the mapped_index::name_components table on demand, and
then binary searches that table.

The .debug_names names index is pretty much the same as the .gdb_index
names index, i.e., a list of fully-qualified names with no
parameter/overload info.  (There's no
what-is-the-language-of-symbol-name info in .debug_names either,
unfortunately.)

So this fixes .debug_names by factoring out the related .gdb_index
code out of the mapped_index class to a base class that is inherited
by both the .gdb_index (mapped_index) and .debug_names
(mapped_debug_names) map classes.

gdb/ChangeLog:
2017-12-08  Pedro Alves  <palves@redhat.com>

	* dwarf2read.c (struct mapped_index_base): New, partially factored
	out from ...
	(struct mapped_index): ... this.  Inherit mapped_index_base.
	(mapped_index::symbol_name_slot_invalid):
	(mapped_index::symbol_name_at): Add override marker.
	(mapped_index::symbol_name_count): New.
	(struct mapped_debug_names): Inherit mapped_index_base.
	(mapped_debug_names::symbol_name_at): New.
	(mapped_debug_names::symbol_name_count): New.
	(mapped_index::find_name_components_bounds): Rename to ...
	(mapped_index_base::find_name_components_bounds): ... this.
	(mapped_index::build_name_components): Rename to ...
	(mapped_index_base::build_name_components): ... this.  Adjust to
	use mapped_index_base::symbol_name_count and
	mapped_index_base::symbol_name_slot_invalid.
	(dw2_expand_symtabs_matching_symbol): Take a mapped_index_base
	instead of a mapped_index.  Use
	dw2_expand_symtabs_matching_symbol.
2017-12-08 23:38:19 +00:00
Pedro Alves
f00a2de2a7 dwarf2read.c:mapped_index, use gdb::array_view, simplify symbol table
This replaces a couple ptr+size pairs with gdb::array_view in the
.gdb_index code, and simplifies things by using an aggregate for the
type of the symbol table hash bucket instead of having to consider the
distinction between size of table vs number of slots and access name
vs vec by index.

gdb/ChangeLog:
2017-12-08  Pedro Alves  <palves@redhat.com>

	* dwarf2read.c (mapped_index::symbol_table_slot): New.
	(mapped_index::address_table): Now a gdb::array_view of const
	gdb_byte.
	(mapped_index::symbol_table): Now a gdb::array_view of
	symbol_table_slot.
	(mapped_index::address_table_size)
	(mapped_index::symbol_table_slots): Delete.
	(create_addrmap_from_index): Adjust.
	(find_slot_in_mapped_hash): Adjust.
	(read_index_from_section): Adjust.
	(dwarf2_read_index): Adjust.
2017-12-08 23:37:42 +00:00
Jan Kratochvil
927aa2e778 DWARF-5: .debug_names index consumer
Some testcases needed to be updated as they were missing
.debug_aranges.  While that does not matter for no-index (as GDB
builds the mapping internally during dwarf2_build_psymtabs_hard) and
neither for .gdb_index (as GDB uses that internally built mapping
which it stores into .gdb_index) it does matter for .debug_names as
that simply assumes existing .debug_aranges from GCC.

gdb/ChangeLog:
2017-12-08  Jan Kratochvil  <jan.kratochvil@redhat.com>
	    Pedro Alves  <palves@redhat.com>

	* defs.h (elf_sym_fns_debug_names): New declaration.
	* dwarf2read.c: Include "hash_enum.h".
	(mapped_debug_names): New.
	(struct dwarf2_per_objfile): Add debug_names, debug_aranges and
	debug_names_table.
	(dwarf2_elf_names): Add ".debug_names" and ".debug_aranges".
	(struct dwz_file): Add debug_names.
	(dwarf2_per_objfile::locate_sections): Handle debug_names and
	debug_aranges.
	(locate_dwz_sections): Handle debug_names.
	(create_signatured_type_table_from_debug_names)
	(create_addrmap_from_aranges): New.
	(dwarf2_read_index): Update function comment.
	(dwarf5_augmentation): Moved up.
	(read_debug_names_from_section, create_cus_from_debug_names_list)
	(create_cus_from_debug_names, dwarf2_read_debug_names): New.
	(dwarf5_djb_hash): Moved up.
	(dw2_debug_names_iterator): New.
	(read_indirect_string_at_offset): New declaration.
	(mapped_debug_names::namei_to_name)
	(dw2_debug_names_iterator::find_vec_in_debug_names)
	(dw2_debug_names_iterator::next, dw2_debug_names_lookup_symbol)
	(dw2_debug_names_dump, dw2_debug_names_expand_symtabs_for_function)
	(dw2_debug_names_expand_symtabs_matching, dwarf2_debug_names_functions):
	New.
	(dwarf2_initialize_objfile): Return also elf_sym_fns_debug_names.
	(debug_names::djb_hash): Rename it to dwarf5_djb_hash.
	(debug_names::build): Update djb_hash caller.
	(write_debug_names): Move out and rename augmentation to
	dwarf5_augmentation.
	* elfread.c (elf_sym_fns_debug_names): New.
	* psymtab.h (dwarf2_debug_names_functions): New declaration.
	* symfile.h (struct dwarf2_debug_sections): Add debug_names and
	debug_aranges.
	* xcoffread.c (dwarf2_xcoff_names): Add debug_names and debug_aranges.

gdb/testsuite/ChangeLog:
2017-12-08  Jan Kratochvil  <jan.kratochvil@redhat.com>
	    Pedro Alves  <palves@redhat.com>

	* gdb.base/maint.exp (check for .gdb_index): Check also for
	.debug_names.
	* gdb.dlang/watch-loc.c (.debug_aranges): New.
	* gdb.dwarf2/dw2-case-insensitive-debug.S: Likewise.
	* gdb.dwarf2/gdb-index.exp (check if index present, .gdb_index used)
	(.gdb_index used after symbol reloading): Support also .debug_names.
	* gdb.mi/dw2-ref-missing-frame-func.c (.debug_aranges): New.
2017-12-08 23:37:31 +00:00
Jan Kratochvil
4b514bc808 Refactor: Move some generic code out of .gdb_index code
Preparation for the next patch.

gdb/ChangeLog
2017-12-08  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* dwarf2read.c (create_cu_from_index_list): New from ...
	(create_cus_from_index_list): ... this function, use it.
	(dw_expand_symtabs_matching_file_matcher)
	(dw2_expand_symtabs_matching_one): New from ...
	(dw2_expand_symtabs_matching): ... this function, use them.
2017-12-08 23:37:30 +00:00
Jan Kratochvil
abccd1e7b7 Change dwarf2_initialize_objfile's return value
dwarf2_initialize_objfile was returning boolean whether it is psymtabs
or .gdb_index while now it needs to return also whether it is
.debug_names.

gdb/ChangeLog
2017-12-08  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* defs.h (elf_sym_fns_lazy_psyms, elf_sym_fns_gdb_index): Move here
	declarations from elfread.c.
	(dwarf2_initialize_objfile): Change return value.
	* elfread.c (elf_sym_fns_lazy_psyms, elf_sym_fns_gdb_index): Move these
	declarations to defs.h.
	(elf_symfile_read): Adjust dwarf2_initialize_objfile caller.
	* symfile.h (dwarf2_initialize_objfile): Change return type.
2017-12-08 23:37:30 +00:00
Jan Kratochvil
437afbb81e DWARF-5: .debug_names index producer
This adds a new "-dwarf-5" switch to "save gdb-index" that makes it
generate index files with DWARF-5 .debug_names/.debug_str sections
instead of GDB's own .gdb_index.

We should probably add a command line option to
contrib/gdb-add-index.sh (incl. cc-with-tweaks.sh) for the new
-dwarf-5 GDB option, and a new target board to make it more convenient
to exercise this.  To be done later.

gdb/ChangeLog
2017-12-08  Jan Kratochvil  <jan.kratochvil@redhat.com>
	    Pedro Alves  <palves@redhat.com>

	* contrib/gdb-add-index.sh (index): Rename to ...
	(index4): ... here.
	(index5, debugstr, debugstrmerge, debugstrerr): New variables.
	Support also .debug_names and .debug_str.
	* dwarf2read.c: Include cmath, set, list.
	(INDEX_SUFFIX): Rename to ...
	(INDEX4_SUFFIX): ... here.
	(INDEX5_SUFFIX, DEBUG_STR_SUFFIX): New.
	(file_write(FILE *, const void *, size_t)): New.
	(file_write(FILE *, const std::vector<Elem, Alloc> &)): New.
	(data_buf::append_unsigned_leb128, data_buf::empty): New.
	(data_buf::file_write): Use ::file_write.
	(data_buf::c_str, dwarf5_djb_hash, debug_names)
	(check_dwarf64_offsets): New.
	(psyms_seen_size, write_gdbindex): New from
	write_psymtabs_to_index code.
	(dwarf5_gdb_augmentation, write_debug_names, assert_file_size)
	(enum dw_index_kind): New.
	(write_psymtabs_to_index): New parameter index_kind.  Support
	filename_str and out_file_str.  Move code to write_gdbindex,
	possibly call write_debug_names.
	(save_gdb_index_command): New parameter -dwarf-5.
	(_initialize_dwarf2_read): Document the new parameter -dwarf-5.

gdb/doc/ChangeLog
2017-12-08  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.texinfo (Index Files): Document .debug_names and -dwarf-5.
--

 gdb/contrib/gdb-add-index.sh |   53 ++
 gdb/doc/gdb.texinfo          |   24 +
 gdb/dwarf2read.c             |  919 ++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 935 insertions(+), 61 deletions(-)
2017-12-08 23:33:27 +00:00
Keith Seitz
883fd55ab1 Record nested types
GDB currently does not track types defined in classes.  Consider:

class A
{
  public:

  class B
  {
    public:
      class C { };
  };
};

(gdb) ptype A
type = class A {
   <no data fields>
}

This patch changes this behavior so that GDB records these nested types
and displays them to the user when he has set the (new) "print type"
option "nested-type-limit."

Example:

(gdb) set print type nested-type-limit 1
(gdb) ptype A
type = class A {
    <no data fields>
    class A::B {
        <no data fields>
    };
}
(gdb) set print type nested-type-limit 2
type = class A {
    <no data fields>
    class A::B {
        <no data fields>
        class A::B::C {
            <no data fields>
        };
    };
}

By default, the code maintains the status quo, that is, it will not print
any nested type definitions at all.

Testing is carried out via cp_ptype_class which required quite a bit of
modification to permit recursive calling (for the nested types).  This
was most easily facilitated by turning the ptype command output into a
queue.  Upshot: the test suite now has stack and queue data structures that
may be used by test writers.

gdb/ChangeLog

	* NEWS (New commands): Mention set/show print type nested-type-limit.
	* c-typeprint.c (c_type_print_base): Print out nested types.
	* dwarf2read.c (struct typedef_field_list): Rename to ...
	(struct decl_field_list): ... this.  Change all uses.
	(struct field_info) <nested_types_list, nested_types_list_count>:
	New fields.
	(add_partial_symbol): Look for nested type definitions in C++, too.
	(dwarf2_add_typedef): Rename to ...
	(dwarf2_add_type_defn): ... this.
	(type_can_define_types): New function.
	Update assertion to use type_can_define_types.
	Permit NULL for a field's name.
	(process_structure_scope): Handle child DIEs of types that can
	define types.
	Copy the list of nested types into the type struct.
	* gdbtypes.h (struct typedef_field): Rename to ...
	(struct decl_field): ... this.  Change all uses.
	[is_protected, is_private]: New fields.
	(struct cplus_struct_type) <nested_types, nested_types_count>: New
	fields.
	(TYPE_NESTED_TYPES_ARRAY, TYPE_NESTED_TYPES_FIELD)
	(TYPE_NESTED_TYPES_FIELD_NAME, TYPE_NESTED_TYPES_FIELD_TYPE)
	(TYPE_NESTED_TYPES_COUNT, TYPE_NESTED_TYPES_FIELD_PROTECTED)
	(TYPE_NESTED_TYPES_FIELD_PRIVATE): New macros.
	* typeprint.c (type_print_raw_options, default_ptype_flags): Add
	default value for print_nested_type_limit.
	(print_nested_type_limit): New static variable.
	(set_print_type_nested_types, show_print_type_nested_types): New
	functions.
	(_initialize_typeprint): Register new commands for set/show
	`print-nested-type-limit'.
	* typeprint.h (struct type_print_options) [print_nested_type_limit]:
	New field.

gdb/testsuite/ChangeLog

	* gdb.cp/nested-types.cc: New file.
	* gdb.cp/nested-types.exp: New file.
	* lib/cp-support.exp: Load data-structures.exp library.
	(debug_cp_test_ptype_class): New global.
	(cp_ptype_class_verbose, next_line): New procedures.
	(cp_test_ptype_class): Add and document new parameter `recursive_qid'.
	Add and document new return value.
	Switch the list of lines to a queue.
	Add support for new `type' key for nested type definitions.
	Add debugging/troubleshooting messages.
	* lib/data-structures.exp: New file.

gdb/doc/ChangeLog

	* gdb.texinfo (Symbols): Document "set print type nested-type-limit"
	and "show print type nested-type-limit".
2017-12-07 15:01:30 -08:00
Simon Marchi
798a7429f9 Remove some unused variables
This patch removes some unused variables, found with -Wunused.  I have
not removed everything reported by -Wunused, because some expressions
such as

  struct type *arg_type = check_typedef (value_type);

in bfin-tdep.c could have an unexpected but important side-effect.  I
removed others that I considered more low-risk, such as:

  struct gdbarch *gdbarch = get_objfile_arch (objfile);

I tested building with Python 2/Python 3/no Python, with/without expat,
with/without libipt and with/without babeltrace.

gdb/ChangeLog:

	* ada-lang.c (ada_collect_symbol_completion_matches): Remove
	unused variables.
	(ada_is_redundant_range_encoding): Likewise.
	* ada-varobj.c (ada_varobj_get_value_of_array_variable):
	Likewise.
	* alpha-tdep.c (alpha_software_single_step): Likewise.
	* arm-tdep.c (_initialize_arm_tdep): Likewise.
	* auto-load.c (info_auto_load_cmd): Likewise.
	* break-catch-syscall.c (insert_catch_syscall): Likewise.
	(remove_catch_syscall): Likewise.
	* breakpoint.c (condition_completer): Likewise.
	(clear_command): Likewise.
	(update_breakpoint_locations): Likewise.
	* btrace.c (btrace_disable): Likewise.
	(btrace_teardown): Likewise.
	(btrace_maint_update_pt_packets): Likewise.
	(maint_btrace_clear_cmd): Likewise.
	* cli/cli-decode.c (lookup_cmd_1): Likewise.
	(lookup_cmd_composition): Likewise.
	* cli/cli-dump.c (scan_filename): Likewise.
	(restore_command): Likewise.
	* compile/compile-loc2c.c (compute_stack_depth): Likewise.
	* compile/compile-object-load.c (compile_object_load): Likewise.
	* compile/compile-object-run.c (compile_object_run): Likewise.
	* compile/compile.c (compile_to_object): Likewise.
	* completer.c (filename_completer): Likewise.
	(complete_files_symbols): Likewise.
	(complete_expression): Likewise.
	* corelow.c (core_open): Likewise.
	* ctf.c (ctf_start): Likewise.
	(ctf_write_status): Likewise.
	(ctf_write_uploaded_tsv): Likewise.
	(ctf_write_definition_end): Likewise.
	(ctf_open_dir): Likewise.
	(ctf_xfer_partial): Likewise.
	(ctf_trace_find): Likewise.
	* disasm.c (gdb_pretty_print_disassembler::pretty_print_insn):
	Likewise.
	* dwarf2loc.c (allocate_piece_closure): Likewise.
	(indirect_pieced_value): Likewise.
	(dwarf2_evaluate_loc_desc_full): Likewise.
	* dwarf2read.c (dw2_expand_marked_cus): Likewise.
	(dw2_expand_symtabs_matching): Likewise.
	(dw2_map_symbol_filenames): Likewise.
	(read_and_check_comp_unit_head): Likewise.
	(read_cutu_die_from_dwo): Likewise.
	(lookup_dwo_unit): Likewise.
	(read_comp_units_from_section): Likewise.
	(dwarf2_compute_name): Likewise.
	(handle_DW_AT_stmt_list): Likewise.
	(create_cus_hash_table): Likewise.
	(create_dwp_v2_section): Likewise.
	(dwarf2_rnglists_process): Likewise.
	(dwarf2_ranges_process): Likewise.
	(dwarf2_record_block_ranges): Likewise.
	(is_vtable_name): Likewise.
	(read_formatted_entries): Likewise.
	(skip_form_bytes): Likewise.
	* elfread.c (elf_symtab_read): Likewise.
	* exec.c (exec_file_command): Likewise.
	* f-valprint.c (f_val_print): Likewise.
	(info_common_command_for_block): Likewise.
	* guile/guile.c (initialize_scheme_side): Likewise.
	* guile/scm-breakpoint.c (gdbscm_breakpoint_commands): Likewise.
	* guile/scm-cmd.c (cmdscm_completer): Likewise.
	(gdbscm_register_command_x): Likewise.
	* guile/scm-frame.c (gdbscm_frame_read_var): Likewise.
	* guile/scm-param.c (gdbscm_parameter_value): Likewise.
	* guile/scm-ports.c (file_port_magic): Likewise.
	* guile/scm-pretty-print.c (ppscm_search_pp_list): Likewise.
	(ppscm_pretty_print_one_value): Likewise.
	(ppscm_print_children): Likewise.
	* guile/scm-string.c (gdbscm_string_to_argv): Likewise.
	* guile/scm-symtab.c (gdbscm_sal_symtab): Likewise.
	* guile/scm-type.c (gdbscm_type_next_field_x): Likewise.
	* guile/scm-utils.c (gdbscm_parse_function_args): Likewise.
	* i386-tdep.c (i386_register_reggroup_p): Likewise.
	* infcmd.c (run_command_1): Likewise.
	(until_next_fsm_clean_up): Likewise.
	* linespec.c (linespec_complete): Likewise.
	(find_label_symbols): Likewise.
	* m2-valprint.c (m2_val_print): Likewise.
	* memattr.c (require_user_regions): Likewise.
	(lookup_mem_region): Likewise.
	(disable_mem_command): Likewise.
	(mem_delete): Likewise.
	* mep-tdep.c (mep_register_name): Likewise.
	(mep_analyze_prologue): Likewise.
	* mi/mi-cmd-file.c (mi_cmd_file_list_shared_libraries): Likewise.
	* mi/mi-interp.c (mi_on_sync_execution_done): Likewise.
	* mi/mi-main.c (mi_cmd_trace_frame_collected): Likewise.
	* microblaze-linux-tdep.c (microblaze_linux_init_abi): Likewise.
	* minidebug.c (lzma_open): Likewise.
	* minsyms.c (lookup_minimal_symbol): Likewise.
	* mips-linux-tdep.c (mips64_fill_fpregset): Likewise.
	* mips-tdep.c (mips_stub_frame_sniffer): Likewise.
	(mips_o64_return_value): Likewise.
	(mips_single_step_through_delay): Likewise.
	(_initialize_mips_tdep): Likewise.
	* nios2-tdep.c (nios2_push_dummy_call): Likewise.
	(nios2_software_single_step): Likewise.
	* parse.c (find_minsym_type_and_address): Likewise.
	* psymtab.c (psym_relocate): Likewise.
	* python/py-breakpoint.c (bppy_get_commands): Likewise.
	(gdbpy_breakpoint_modified): Likewise.
	* python/py-infevents.c (create_inferior_call_event_object):
	Likewise.
	* python/py-record-btrace.c (btpy_list_item): Likewise.
	* python/py-type.c (typy_str): Likewise.
	* python/py-value.c (valpy_call): Likewise.
	* python/python.c (do_start_initialization): Likewise.
	* record-btrace.c (record_btrace_insn_history_range): Likewise.
	(record_btrace_call_history_range): Likewise.
	(record_btrace_record_method): Likewise.
	(record_btrace_xfer_partial): Likewise.
	(btrace_get_frame_function): Likewise.
	* record-full.c (record_full_open): Likewise.
	* record.c (get_context_size): Likewise.
	* registry.h (DEFINE_REGISTRY): Likewise.
	* remote-fileio.c (remote_fileio_request): Likewise.
	* remote.c (remote_update_thread_list): Likewise.
	(remote_check_symbols): Likewise.
	(remote_commit_resume): Likewise.
	(remote_interrupt): Likewise.
	(remote_insert_breakpoint): Likewise.
	(compare_sections_command): Likewise.
	* rust-exp.y (super_name): Likewise.
	(lex_string): Likewise.
	(convert_ast_to_type): Likewise.
	(convert_ast_to_expression): Likewise.
	* rust-lang.c (rust_print_struct_def): Likewise.
	(rust_print_type): Likewise.
	(rust_evaluate_subexp): Likewise.
	* rx-tdep.c (rx_register_type): Likewise.
	* ser-event.c (serial_event_clear): Likewise.
	* serial.c (serial_open): Likewise.
	* spu-tdep.c (spu_overlay_new_objfile): Likewise.
	* symfile.c (section_is_overlay): Likewise.
	(overlay_unmapped_address): Likewise.
	(overlay_mapped_address): Likewise.
	(simple_overlay_update_1): Likewise.
	(simple_overlay_update): Likewise.
	* symtab.c (symbol_find_demangled_name): Likewise.
	(search_symbols): Likewise.
	* target-descriptions.c (tdesc_predefined_type): Likewise.
	* target.c (target_commit_resume): Likewise.
	* thread.c (print_selected_thread_frame): Likewise.
	* top.c (new_ui_command): Likewise.
	(gdb_readline_no_editing): Likewise.
	* tracefile-tfile.c (tfile_open): Likewise.
	* tracepoint.c (create_tsv_from_upload): Likewise.
	* utils.c (quit): Likewise.
	(defaulted_query): Likewise.
	* valarith.c (value_concat): Likewise.
	* xml-syscall.c (xml_list_syscalls_by_group): Likewise.
	* xml-tdesc.c (target_fetch_description_xml): Likewise.
	* xtensa-tdep.c (xtensa_pseudo_register_read): Likewise.
	(xtensa_pseudo_register_write): Likewise.

gdb/gdbserver/ChangeLog:

	* regcache.c (registers_to_string): Remove unused variable.
2017-12-05 16:05:50 -05:00
Sergio Durigan Junior
97cbe998d0 Add support for the readnever concept
The purpose of this concept is to turn the load of debugging
information off, either globally (via the '--readnever' option), or
objfile-specific.  The implementation proposed here is an extension of
the patch distributed with Fedora GDB; looking at the Fedora patch
itself and the history, one can see some reasons why it was never
resubmitted:

  - The patch appears to have been introduced as a workaround, at
    least initially;
  - The patch is far from perfect, as it simply shunts the load of
    DWARF debugging information, without really worrying about the
    other debug format.
  - Who really does non-symbolic debugging anyways?

One use of this feature is when a user simply wants to do the
following sequence: attach, dump core, detach.  Loading the debugging
information in this case is an unnecessary cause of delay.

This patch expands the version shipped with Fedora GDB in order to
make the feature available for all the debuginfo backends, not only
for DWARF.  It also implements a per-objfile flag which can be
activated by using the "-readnever" command when using the
'add-symbol-file' or 'symbol-file' commands.

It's also worth mentioning that this patch tests whether GDB correctly
fails to initialize if both '--readnow' and '--readnever' options are
passed.

Tested on the BuildBot.

gdb/ChangeLog:

2017-12-01  Andrew Cagney  <cagney@redhat.com>
	    Joel Brobecker  <brobecker@adacore.com>
	    Sergio Durigan Junior  <sergiodj@redhat.com>

	* NEWS (Changes since GDB 8.0: Mention new '--readnever'
	feature.
	* coffread.c (coff_symfile_read): Do not map over sections with
	'coff_locate_sections' if readnever is on.
	* dwarf2read.c (dwarf2_has_info): Return 0 if
	readnever is on.
	* elfread.c (elf_symfile_read): Do not map over sections with
	'elf_locate_sections' if readnever is on.
	* main.c (validate_readnow_readnever): New function.
	(captured_main_1): Add support for --readnever.
	(print_gdb_help): Document --readnever.
	* objfile-flags.h (enum objfile_flag) <OBJF_READNEVER>: New
	flag.
	* symfile.c (readnever_symbol_files): New global.
	(symbol_file_add_with_addrs): Set 'OBJF_READNEVER' when
	'READNEVER_SYMBOL_FILES' is set.
	(validate_readnow_readnever): New function.
	(symbol_file_command): Handle '-readnever' option.
	Call 'validate_readnow_readnever'.
	(add_symbol_file_command): Handle '-readnever' option.
	Call 'validate_readnow_readnever'.
	(_initialize_symfile): Document new '-readnever' option for
	both 'symbol-file' and 'add-symbol-file' commands.
	* top.h (readnever_symbol_files): New extern global.
	* xcoffread.c (xcoff_initial_scan): Do not read debug
	information if readnever is on.

gdb/doc/ChangeLog:

2017-12-01  Andrew Cagney  <cagney@redhat.com>
	    Joel Brobecker  <brobecker@adacore.com>
	    Sergio Durigan Junior  <sergiodj@redhat.com>

	* gdb.texinfo (File Options): Document --readnever.
	(Commands to Specify Files): Likewise, for 'symbol-file' and
	'add-symbol-file'.

gdb/testsuite/ChangeLog:

2017-12-01  Joel Brobecker  <brobecker@adacore.com>
	    Sergio Durigan Junior  <sergiodj@redhat.com>
	    Pedro Alves  <palves@redhat.com>

	* gdb.base/readnever.c, gdb.base/readnever.exp: New files.
2017-12-01 21:28:31 -05:00
Sergio Durigan Junior
7f0f8ac8b1 Revert "Add support for the readnever concept"
This reverts commit e2e321740c.

It was mistakenly pushed.
2017-12-01 16:58:47 -05:00
Sergio Durigan Junior
e2e321740c Add support for the readnever concept
The purpose of this concept is to turn the load of debugging
information off, either globally (via the '--readnever' option), or
objfile-specific.  The implementation proposed here is an extension of
the patch distributed with Fedora GDB; looking at the Fedora patch
itself and the history, one can see some reasons why it was never
resubmitted:

  - The patch appears to have been introduced as a workaround, at
    least initially;
  - The patch is far from perfect, as it simply shunts the load of
    DWARF debugging information, without really worrying about the
    other debug format.
  - Who really does non-symbolic debugging anyways?

One use of this feature is when a user simply wants to do the
following sequence: attach, dump core, detach.  Loading the debugging
information in this case is an unnecessary cause of delay.

This patch expands the version shipped with Fedora GDB in order to
make the feature available for all the debuginfo backends, not only
for DWARF.  It also implements a per-objfile flag which can be
activated by using the "-readnever" command when using the
'add-symbol-file' or 'symbol-file' commands.

It's also worth mentioning that this patch tests whether GDB correctly
fails to initialize if both '--readnow' and '--readnever' options are
passed.

Tested on the BuildBot.

gdb/ChangeLog:

2017-12-01  Andrew Cagney  <cagney@redhat.com>
	    Joel Brobecker  <brobecker@adacore.com>
	    Sergio Durigan Junior  <sergiodj@redhat.com>

	* NEWS (Changes since GDB 8.0: Mention new '--readnever'
	feature.
	* coffread.c (coff_symfile_read): Do not map over sections with
	'coff_locate_sections' if readnever is on.
	* dwarf2read.c (dwarf2_has_info): Return 0 if
	readnever is on.
	* elfread.c (elf_symfile_read): Do not map over sections with
	'elf_locate_sections' if readnever is on.
	* main.c (validate_readnow_readnever): New function.
	(captured_main_1): Add support for --readnever.
	(print_gdb_help): Document --readnever.
	* objfile-flags.h (enum objfile_flag) <OBJF_READNEVER>: New
	flag.
	* symfile.c (readnever_symbol_files): New global.
	(symbol_file_add_with_addrs): Set 'OBJF_READNEVER' when
	'READNEVER_SYMBOL_FILES' is set.
	(validate_readnow_readnever): New function.
	(symbol_file_command): Handle '-readnever' option.
	Call 'validate_readnow_readnever'.
	(add_symbol_file_command): Handle '-readnever' option.
	Call 'validate_readnow_readnever'.
	(_initialize_symfile): Document new '-readnever' option for
	both 'symbol-file' and 'add-symbol-file' commands.
	* top.h (readnever_symbol_files): New extern global.
	* xcoffread.c (xcoff_initial_scan): Do not read debug
	information if readnever is on.

gdb/doc/ChangeLog:

2017-12-01  Andrew Cagney  <cagney@redhat.com>
	    Joel Brobecker  <brobecker@adacore.com>
	    Sergio Durigan Junior  <sergiodj@redhat.com>

	* gdb.texinfo (File Options): Document --readnever.
	(Commands to Specify Files): Likewise, for 'symbol-file' and
	'add-symbol-file'.

gdb/testsuite/ChangeLog:

2017-12-01  Joel Brobecker  <brobecker@adacore.com>
	    Sergio Durigan Junior  <sergiodj@redhat.com>
	    Pedro Alves  <palves@redhat.com>

	* gdb.base/readnever.c, gdb.base/readnever.exp: New files.
2017-12-01 12:23:30 -05:00
Pedro Alves
a20714ff39 Make "break foo" find "A::foo", A::B::foo", etc. [C++ and wild matching]
This patch teaches GDB about setting breakpoints in all scopes
(namespaces and classes) by default.

Here's a contrived example:

  (gdb) b func<tab>
  (anonymous namespace)::A::function()            Bn::(anonymous namespace)::B::function()        function(int, int)
  (anonymous namespace)::B::function()            Bn::(anonymous namespace)::function()           gdb::(anonymous namespace)::A::function()
  (anonymous namespace)::B::function() const      Bn::(anonymous namespace)::function(int, int)   gdb::(anonymous namespace)::function()
  (anonymous namespace)::function()               Bn::B::func()                                   gdb::(anonymous namespace)::function(int, int)
  (anonymous namespace)::function(int, int)       Bn::B::function()                               gdb::A::func()
  A::func()                                       Bn::func()                                      gdb::A::function()
  A::function()                                   Bn::function()                                  gdb::func()
  B::func()                                       Bn::function(int, int)                          gdb::function()
  B::function()                                   Bn::function(long)                              gdb::function(int, int)
  B::function() const                             func()                                          gdb::function(long)
  B::function_const() const                       function()
  (gdb) b function
  Breakpoint 1 at 0x4005ce: function. (26 locations)

  (gdb) b B::function<tab>
  (anonymous namespace)::B::function()        B::function() const                         Bn::B::function()
  (anonymous namespace)::B::function() const  B::function_const() const
  B::function()                               Bn::(anonymous namespace)::B::function()
  (gdb) b B::function
  Breakpoint 1 at 0x40072c: B::function. (6 locations)

To get back the original behavior of interpreting the function name as
a fully-qualified name, you can use the new "-qualified" (or "-q")
option/flag (added by this commit).  For example:

 (gdb) b B::function
 (anonymous namespace)::B::function()        B::function() const                         Bn::B::function()
 (anonymous namespace)::B::function() const  B::function_const() const
 B::function()                               Bn::(anonymous namespace)::B::function()

vs:

 (gdb) b -qualified B::function
 B::function()              B::function() const        B::function_const() const

I've chosen "-qualified" / "-q" because "-f" (for "full" or
"fully-qualified") is already taken for "-function".

Note: the "-qualified" option works with both linespecs and explicit
locations.  I.e., these are equivalent:

 (gdb) b -q func
 (gdb) b -q -f func

and so are these:

 (gdb) b -q filename.cc:func
 (gdb) b -q -s filename.cc -f func
 (gdb) b -s filename.cc -q -f func
 (gdb) b -s filename.cc -f func -q

To better understand why I consider wild matching the better default,
consider what happens when we get to the point when _all_ of GDB is
wrapped under "namespace gdb {}".  I have a patch series that does
that, and when I started debugging that GDB, I immediately became
frustrated.  You'd have to write "b gdb::internal_error", "b
gdb::foo", "b gdb::bar", etc. etc., which gets annoying pretty
quickly.  OTOH, consider how this makes it very easy to set
breakpoints in classes wrapped in anonymous namespaces.  You just
don't think of them, GDB finds the symbols for you automatically.

(At the Cauldron a couple months ago, several people told me that they
run into a similar issue when debugging other C++ projects.  One
example was when debugging LLVM, which puts all its code under the
"llvm" namespace.)

Implementation-wise, what the patch does is:

  - makes C++ symbol name hashing only consider the last component of
    a symbol name. (so that we can look up symbol names by
    last-component name only).

  - adds a C++ symbol name matcher for symbol_name_match_type::WILD,
    which ignores missing leading specifiers / components.

  - adjusts a few preexisting testsuite tests to use "-qualified" when
    they mean it.

  - adds new testsuite tests.

  - adds unit tests.

Grows the gdb.linespec/ tests like this:

  -# of expected passes           7823
  +# of expected passes           8977

gdb/ChangeLog:
2017-11-29  Pedro Alves  <palves@redhat.com>

	* NEWS: Mention that breakpoints on C++ functions are now set on
	on all namespaces/classes by default, and mention "break
	-qualified".
	* ax-gdb.c (agent_command_1): Adjust to pass a
	symbol_name_match_type to new_linespec_location.
	* breakpoint.c (parse_breakpoint_sals): Adjust to
	get_linespec_location's return type change.
	(strace_marker_create_sals_from_location): Adjust to pass a
	symbol_name_match_type to new_linespec_location.
	(strace_marker_decode_location): Adjust to get_linespec_location's
	return type change.
	(strace_command): Adjust to pass a symbol_name_match_type to
	new_linespec_location.
	(LOCATION_HELP_STRING): Add paragraph about wildmatching, and
	mention "-qualified".
	* c-lang.c (cplus_language_defn): Install cp_search_name_hash.
	* completer.c (explicit_location_match_type::MATCH_QUALIFIED): New
	enumerator.
	(complete_address_and_linespec_locations): New parameter
	'match_type'.  Pass it down.
	(explicit_options): Add "-qualified".
	(collect_explicit_location_matches): Pass the requested match type
	to the linespec completers.  Handle MATCH_QUALIFIED.
	(location_completer): Handle "-qualified" combined with linespecs.
	* cp-support.c (cp_search_name_hash): New.
	(cp_symbol_name_matches_1): Implement wild matching for C++.
	(cp_fq_symbol_name_matches): Reimplement.
	(cp_get_symbol_name_matcher): Return different matchers depending
	on the lookup name's match type.
	(selftests::test_cp_symbol_name_matches): Add wild matching tests.
	* cp-support.h (cp_search_name_hash): New declaration.
	* dwarf2read.c
	(selftests::dw2_expand_symtabs_matching::test_symbols): Add
	symbols.
	(test_dw2_expand_symtabs_matching_symbol): Add wild matching
	tests.
	* guile/scm-breakpoint.c (gdbscm_register_breakpoint_x): Adjust to
	pass a symbol_name_match_type to new_linespec_location.
	* linespec.c (linespec_parse_basic): Lookup function symbols using
	the parser's symbol name match type.
	(convert_explicit_location_to_linespec): New
	symbol_name_match_type parameter.  Pass it down to
	find_linespec_symbols.
	(convert_explicit_location_to_sals): Pass the location's name
	match type to convert_explicit_location_to_linespec.
	(parse_linespec): New match_type parameter.  Save it in the
	parser.
	(linespec_parser_new): Default to symbol_name_match_type::WILD.
	(linespec_complete_function): New symbol_name_match_type
	parameter.  Use it.
	(complete_linespec_component): Pass down the parser's recorded
	name match type.
	(linespec_complete_label): New symbol_name_match_type parameter.
	Use it.
	(linespec_complete): New symbol_name_match_type parameter.  Save
	it in the parser and pass it down.  Adjust to
	get_linespec_location's prototype change.
	(find_function_symbols, find_linespec_symbols): New
	symbol_name_match_type parameter.  Pass it down instead of
	assuming symbol_name_match_type::WILD.
	* linespec.h (linespec_complete, linespec_complete_function)
	(linespec_complete_label): New symbol_name_match_type parameter.
	* location.c (event_location::linespec_location): Now a struct
	linespec_location.
	(EL_LINESPEC): Adjust.
	(initialize_explicit_location): Default to
	symbol_name_match_type::WILD.
	(new_linespec_location): New symbol_name_match_type parameter.
	Record it in the location.
	(get_linespec_location): Now returns a struct linespec_location.
	(new_explicit_location): Also copy func_name_match_type.
	(explicit_to_string_internal)
	(string_to_explicit_location): Handle "-qualified".
	(copy_event_location): Adjust to LINESPEC_LOCATION type change.
	Copy symbol_name_match_type fields.
	(event_location_deleter::operator()): Adjust to LINESPEC_LOCATION
	type change.
	(event_location_to_string): Adjust to LINESPEC_LOCATION type
	change.  Handle "-qualfied".
	(string_to_explicit_location): Handle "-qualified".
	(string_to_event_location_basic): New symbol_name_match_type
	parameter.  Pass it down.
	(string_to_event_location): Handle "-qualified".
	* location.h (struct linespec_location): New.
	(explicit_location::func_name_match_type): New field.
	(new_linespec_location): Now returns a const linespec_location *.
	(string_to_event_location_basic): New symbol_name_match_type
	parameter.
	(explicit_completion_info::saw_explicit_location_option): New
	field.
	* mi/mi-cmd-break.c (mi_cmd_break_insert_1): Adjust to pass a
	symbol_name_match_type to new_linespec_location.
	* python/py-breakpoint.c (bppy_init): Likewise.
	* python/python.c (gdbpy_decode_line): Likewise.

gdb/testsuite/ChangeLog:
2017-11-29  Pedro Alves  <palves@redhat.com>

	* gdb.base/langs.exp: Use -qualified.
	* gdb.cp/meth-typedefs.exp: Use -qualified, and add tests without
	it.
	* gdb.cp/namespace.exp: Use -qualified.
	* gdb.linespec/cpcompletion.exp (overload-2, fqn, fqn-2)
	(overload-3, template-overload, template-ret-type, const-overload)
	(const-overload-quoted, anon-ns, ambiguous-prefix): New
	procedures.
	(test_driver): Call them.
	* gdb.cp/save-bp-qualified.cc: New.
	* gdb.cp/save-bp-qualified.exp: New.
	* gdb.linespec/explicit.exp: Test -qualified.
	* lib/completion-support.exp (completion::explicit_opts_list): Add
	"-qualified".
	* lib/gdb.exp (gdb_breakpoint): Handle "qualified".

gdb/doc/ChangeLog:
2017-11-29  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (Linespec Locations): Document how "function" is
	interpreted in C++ and Ada.  Document "-qualified".
	(Explicit Locations): Document how "-function" is interpreted in
	C++ and Ada.  Document "-qualified".
2017-11-29 19:43:48 +00:00
Pedro Alves
e6b2f5efa9 Fix mapped_index::find_name_components_bounds upper bound computation
Here we want to find where we'd insert "after", so we want
std::lower_bound, not std::upper_bound.

gdb/ChangeLog:
2017-11-21  Pedro Alves  <palves@redhat.com>

	* dwarf2read.c (mapped_index::find_name_components_bounds)
	<completion mode, upper bound>: Use std::lower_bound instead of
	std::upper_bound.
	(test_mapped_index_find_name_component_bounds): Remove incorrect
	"t1_fund" from expected symbols.
2017-11-21 00:03:27 +00:00
Pedro Alves
5c58de74c9 Unit test name-component bounds searching directly
This commit factors out the name-components-vector building and bounds
searching out of dw2_expand_symtabs_matching_symbol into separate
functions, and adds unit tests that:

 - expose both the latent bug mentioned in the previous commit, and
   also,

 - for completeness exercise the 0xff character handling fixed in the
   previous commit more directly.

The actual fix for the now-exposed bug is left for the following
patch.

gdb/ChangeLog:
2017-11-21  Pedro Alves  <palves@redhat.com>

	* dwarf2read.c (mapped_index::name_components_casing): New field.
	(mapped_index) <build_name_components,
	find_name_components_bounds): Declare new methods.
	(mapped_index::find_name_components_bounds)
	(mapped_index::build_name_components): New methods, factored out
	from dw2_expand_symtabs_matching_symbol.
	(check_find_bounds_finds)
	(test_mapped_index_find_name_component_bounds): New.
	(run_test): Rename to ...
	(test_dw2_expand_symtabs_matching_symbol): ... this.
	(run_test): Reimplement.
2017-11-21 00:03:10 +00:00
Pedro Alves
e1ef7d7a51 0xff chars in name components table; cp-name-parser lex UTF-8 identifiers
The find-upper-bound-for-completion algorithm in the name components
accelerator table in dwarf2read.c increments a char in a string, and
asserts that it's not incrementing a 0xff char, but that's incorrect.

First, we shouldn't be calling gdb_assert on input.

Then, if "char" is signed, comparing a caracther with "0xff" will
never yield true, which is caught by Clang with:

  error: comparison of constant 255 with expression of type '....' (aka 'char') is always true [-Werror,-Wtautological-constant-out-of-range-compare]
	    gdb_assert (after.back () != 0xff);
			~~~~~~~~~~~~~ ^  ~~~~

And then, 0xff is a valid character on non-UTF-8/ASCII character sets.
E.g., it's 'ÿ' in Latin1.  While GCC nor Clang support !ASCII &&
!UTF-8 characters in identifiers (GCC supports UTF-8 characters only
via UCNs, see https://gcc.gnu.org/onlinedocs/cpp/Character-sets.html),
but other compilers might (Visual Studio?), so it doesn't hurt to
handle it correctly.  Testing is covered by extending the
dw2_expand_symtabs_matching unit tests with relevant cases.

However, without further changes, the unit tests still fail...  The
problem is that cp-name-parser.y assumes that identifiers are ASCII
(via ISALPHA/ISALNUM).  This commit fixes that too, so that we can
unit test the dwarf2read.c changes.  (The regular C/C++ lexer in
c-lang.y needs a similar treatment, but I'm leaving that for another
patch.)

While doing this, I noticed a thinko in the computation of the upper
bound for completion in dw2_expand_symtabs_matching_symbol.  We're
using std::upper_bound but we should use std::lower_bound.  I extended
the unit test with a case that I thought would expose it, this one:

 +  /* These are used to check that the increment-last-char in the
 +     matching algorithm for completion doesn't match "t1_fund" when
 +     completing "t1_func".  */
 +  "t1_func",
 +  "t1_func1",
 +  "t1_fund",
 +  "t1_fund1",

The algorithm actually returns "t1_fund1" as lower bound, so "t1_fund"
matches incorrectly.  But turns out the problem is masked because
later here:

  for (;lower != upper; ++lower)
    {
      const char *qualified = index.symbol_name_at (lower->idx);

      if (!lookup_name_matcher.matches (qualified)

the lookup_name_matcher.matches check above filters out "t1_fund"
because that doesn't start with "t1_func".

I'll fix the latent bug in follow up patches, after factoring things
out a bit in a way that allows unit testing the relevant code more
directly.

gdb/ChangeLog:
2017-11-21  Pedro Alves  <palves@redhat.com>

	* cp-name-parser.y (cp_ident_is_alpha, cp_ident_is_alnum): New.
	(symbol_end): Use cp_ident_is_alnum.
	(yylex): Use cp_ident_is_alpha and cp_ident_is_alnum.
	* dwarf2read.c (make_sort_after_prefix_name): New function.
	(dw2_expand_symtabs_matching_symbol): Use it.
	(test_symbols): Add more symbols.
	(run_test): Add tests.
2017-11-21 00:02:46 +00:00
Tom Tromey
cf724bc93e Use an enum to represent subclasses of symbol
This changes struct symbol to use an enum to encode the concrete
subclass of a particular symbol.  Note that "enum class" doesn't work
properly with bitfields, so a plain enum is used.

2017-11-17  Tom Tromey  <tom@tromey.com>

	* symtab.h (enum symbol_subclass_kind): New.
	(struct symbol) <is_cplus_template_function, is_rust_vtable>:
	Remove.
	<subclass>: New member.
	(SYMBOL_IS_CPLUS_TEMPLATE_FUNCTION): Update.
	* rust-lang.c (rust_get_trait_object_pointer): Update.
	* dwarf2read.c (read_func_scope): Update.
	(read_variable): Update.
2017-11-17 14:34:14 -07:00
Tom Tromey
68e745e38e Make template_symbol derive from symbol
This changes template_symbol to derive from symbol, which seems a bit
cleaner; and also more consistent with rust_vtable_symbol.

2017-11-17  Tom Tromey  <tom@tromey.com>

	* dwarf2read.c (read_func_scope): Update.
	* symtab.h (struct template_symbol): Derive from symbol.
	<base>: Remove.
2017-11-17 14:34:14 -07:00
Tom Tromey
71a3c36949 Handle dereferencing Rust trait objects
In Rust, virtual tables work a bit differently than they do in C++.  In
C++, as you know, they are connected to a particular class hierarchy.
Rust, instead, can generate a virtual table for potentially any type --
in fact, one such virtual table for each trait (a trait is similar to an
abstract class or to a Java interface) that a type implements.

Objects that are referenced via a trait can't currently be inspected by
gdb.  This patch implements the Rust equivalent of "set print object".

gdb relies heavily on the C++ ABI to decode virtual tables; primarily to
make "set print object" work; but also "info vtbl".  However, Rust does
not currently have a specified ABI, so this approach seems unwise to
emulate.

Instead, I've changed the Rust compiler to emit some DWARF that
describes trait objects (previously their internal structure was
opaque), vtables (currently just a size -- but I hope to expand this in
the future), and the concrete type for which a vtable was emitted.

The concrete type is expressed as a DW_AT_containing_type on the
vtable's type.  This is a small extension to DWARF.

This patch adds a new entry to quick_symbol_functions to return the
symtab that holds a data address.  Previously there was no way in gdb to
look up a full (only minimal) non-text symbol by address.  The psymbol
implementation of this method works by lazily filling in a map that is
added to the objfile.  This avoids slowing down psymbol reading for a
feature that is likely to not be used too frequently.

I did not update .gdb_index.  My thinking here is that the DWARF 5
indices will obsolete .gdb_index soon-ish, meaning that adding a new
feature to them is probably wasted work.  If necessary I can update the
DWARF 5 index code when it lands in gdb.

Regression tested on x86-64 Fedora 25.

2017-11-17  Tom Tromey  <tom@tromey.com>

	* symtab.h (struct symbol) <is_rust_vtable>: New member.
	(struct rust_vtable_symbol): New.
	(find_symbol_at_address): Declare.
	* symtab.c (find_symbol_at_address): New function.
	* symfile.h (struct quick_symbol_functions)
	<find_compunit_symtab_by_address>: New member.
	* symfile-debug.c (debug_qf_find_compunit_symtab_by_address): New
	function.
	(debug_sym_quick_functions): Link to
	debug_qf_find_compunit_symtab_by_address.
	* rust-lang.c (rust_get_trait_object_pointer): New function.
	(rust_evaluate_subexp) <case UNOP_IND>: New case.  Call
	rust_get_trait_object_pointer.
	* psymtab.c (psym_relocate): Clear psymbol_map.
	(psym_fill_psymbol_map, psym_find_compunit_symtab_by_address): New
	functions.
	(psym_functions): Link to psym_find_compunit_symtab_by_address.
	* objfiles.h (struct objfile) <psymbol_map>: New member.
	* dwarf2read.c (dwarf2_gdb_index_functions): Update.
	(process_die) <DW_TAG_variable>: New case.  Call read_variable.
	(rust_containing_type, read_variable): New functions.

2017-11-17  Tom Tromey  <tom@tromey.com>

	* gdb.rust/traits.rs: New file.
	* gdb.rust/traits.exp: New file.
2017-11-17 14:34:14 -07:00
Tom Tromey
2f4732b0e6 Remove symbolp vector
This removes the symbolp typedef from dwarf2read.c and converts the
associated VEC uses to std::vector.  This fixes a latent possible
memory leak if an exception were thrown, because there were no
cleanups installed for these VECs.

Regression tested on the buildbot.

gdb/ChangeLog
2017-11-08  Tom Tromey  <tom@tromey.com>

	* dwarf2read.c (symbolp): Remove typedef.
	(read_func_scope): Use std::vector.
	(process_structure_scope): Use std::vector.
2017-11-08 11:20:14 -07:00
Pedro Alves
c62446b12b lookup_name_info::make_ignore_params
A few places in the completion code look for a "(" to find a
function's parameter list, in order to strip it, because psymtabs (and
gdb index) don't include parameter info in the symbol names.

See compare_symbol_name and
default_collect_symbol_completion_matches_break_on.

This is too naive.  Consider:

 ns_overload2_test::([TAB]

We'd want to complete that to:
 ns_overload2_test::(anonymous namespace)::struct_overload2_test

Or:

 b (anonymous namespace)::[TAB]

That currently completes to:

 b (anonymous namespace)

Which is obviously broken.  This patch makes that work.

Also, the current compare_symbol_name hack means that while this
works:

 "b function([TAB]"  ->  "b function()"

This does not:

 "b function ([TAB]"

This patch fixes that.  Whitespace "ignoring" now Just Works, i.e.,
assuming a symbol named "function(int, long)", this:
 b function (   int , lon[TAB]
completes to:
 b function (   int , long)

To address all of this, this patch builds on top of the rest of the
series, and pushes the responsibility of stripping parameters from a
lookup name to the new lookup_name_info object, where we can apply
per-language rules.  Also note that we now only make a version of the
lookup name with parameters stripped out where it's actually required
to do that, in the psymtab and GDB index code.

For C++, the right way to strip parameters is with "cp_remove_params",
which uses a real parser (cp-name-parser.y) to split the name into a
component tree and then discards parameters.

The trouble for completion is that in that case we have an incomplete
name, like "foo::func(int" and thus cp_remove_params throws an error.

This patch sorts that by adding a cp_remove_params_if_any variant of
cp_remove_params that tries removing characters from the end of the
string until cp_remove_params works.  So cp_remove_params_if_any
behaves like this:

With a complete name:

   "foo::func(int)"  => foo::func(int)  # cp_remove_params_1 succeeds the first time.

With an incomplete name:

   "foo::func(int"  => NULL             # cp_remove_params fails the first time.
   "foo::func(in"   => NULL             # and again...
   "foo::func(i"    => NULL             # and again...
   "foo::func("     => NULL             # and again...
   "foo::func"      => "foo::func"      # success!

Note that even if this approach removes significant rightmost
characters, it's still OK, because this parameter stripping is only
necessary for psymtabs and gdb index, where we're determining whether
to expand a symbol table.  Say cp_remove_params_if_any returned
"foo::" above for "foo::func(int".  That'd cause us to expand more
symtabs than ideal (because we'd expand all symtabs with symbols that
start with "foo::", not just "foo::func"), but then when we actually
look for completion matches, we'd still use the original lookup name,
with parameter information ["foo::func(int"], and thus we'll return no
false positive to the user.  Whether the stripping works as intended
and doesn't strip too much is thus covered by a unit test instead of a
testsuite test.

The "if_any" part of the name refers to the fact that while
cp_remove_params returns NULL if the input name has no parameters in
the first place, like:

   "foo::func"      => NULL         # cp_remove_params

cp_remove_params_if_any still returns the function name:

   "foo::func"      => "foo::func"  # cp_remove_params_if_any

gdb/ChangeLog:
2017-11-08  Pedro Alves  <palves@redhat.com>

	* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
	unittests/lookup_name_info-selftests.c.
	(SUBDIR_UNITTESTS_OBS): Add lookup_name_info-selftests.o.
	* cp-support.c: Include "selftest.h".
	(cp_remove_params_1): Rename from cp_remove_params.  Add
	'require_param' parameter, and handle it.
	(cp_remove_params): Reimplement.
	(cp_remove_params_if_any): New.
	(selftests::quote): New.
	(selftests::check_remove_params): New.
	(selftests::test_cp_remove_params): New.
	(_initialize_cp_support): Install
	selftests::test_cp_remove_params.
	* cp-support.h (cp_remove_params_if_any): Declare.
	* dwarf2read.c :Include "selftest.h".
	(dw2_expand_symtabs_matching_symbol): Use
	lookup_name_info::make_ignore_params.
	(selftests::dw2_expand_symtabs_matching::mock_mapped_index)
	(selftests::dw2_expand_symtabs_matching::string_or_null)
	(selftests::dw2_expand_symtabs_matching::check_match)
	(selftests::dw2_expand_symtabs_matching::test_symbols)
	(selftests::dw2_expand_symtabs_matching::run_test): New.
	(_initialize_dwarf2_read): Register
	selftests::dw2_expand_symtabs_matching::run_test.
	* psymtab.c (psym_expand_symtabs_matching): Use
	lookup_name_info::make_ignore_params.
	* symtab.c (demangle_for_lookup_info::demangle_for_lookup_info):
	If the lookup name wants to ignore parameters, strip them.
	(compare_symbol_name): Remove sym_text/sym_text_len parameters and
	code handling '('.
	(completion_list_add_name): Don't pass down sym_text/sym_text_len.
	(default_collect_symbol_completion_matches_break_on): Don't try to
	strip parameters.
	* symtab.h (lookup_name_info::lookup_name_info): Add
	'ignore_parameters' parameter.
	(lookup_name_info::ignore_parameters)
	(lookup_name_info::make_ignore_params): New methods.
	(lookup_name_info::m_ignore_parameters): New field.
	* unittests/lookup_name_info-selftests.c: New file.
2017-11-08 16:02:24 +00:00
Pedro Alves
61920122ba Reorder/reindent dw2_expand_symtabs_matching & friends
The previous patch had added dw2_expand_symtabs_matching_symbol and
dw2_expand_marked_cus forward declarations and did not reindent
dw2_expand_marked_cus to avoid moving the code around while changing
it at the same time.

gdb/ChangeLog:
2017-11-08  Pedro Alves  <palves@redhat.com>

	* dwarf2read.c (dw2_expand_marked_cus)
	(dw2_expand_symtabs_matching_symbol): Remove forward declarations.
	(dw2_expand_symtabs_matching): Move further below.
	(dw2_expand_marked_cus): Reindent.
2017-11-08 16:02:24 +00:00
Pedro Alves
3f563c840a Optimize .gdb_index symbol name searching
As mentioned in the previous patch, .gdb_index name lookup got
significantly slower with the previous patch.

This patch addresses that, and in the process makes .gdb_index name
searching faster than what we had before the previous patch, even.
Using the same test:

 $ cat script.cmd
 set pagination off
 set $count = 0
 while $count < 400
   complete b string_prin
   printf "count = %d\n", $count
   set $count = $count + 1
 end

 $ time gdb --batch -q ./gdb-with-index -ex "source script.cmd"

I got, before the previous patch (-O2, x86-64):

 real    0m1.773s
 user    0m1.737s
 sys     0m0.040s

and after this patch:

 real    0m1.361s
 user    0m1.315s
 sys     0m0.040s

The basic idea here is simple: instead of always iterating over all
the symbol names in the index, we build an accelerator/sorted name
table and binary search names in it.

Later in the series, we'll want to support wild matching for C++ too,
so this mechanism already considers that.  For example, say that
you're looking up functions/methods named "func", no matter the
containing namespace/class.  If we sorted the table by qualified name,
then we obviously wouldn't be able to find those symbols with a binary
search:

  func
  ns1:🅰️🅱️:func
  ns1:🅱️:func
  ns2::func

(function symbol names in .gdb_index have no parameter info, like psymbols)

To address that out, we put an entry for each name component in the
sorted table.  something like this:

  Table Entry       Actual symbol
  ---------------------------------
  func              func

  func              ns1:🅰️🅱️:func
  b::func           ns1:🅰️🅱️:func
  a:🅱️:func        ns1:🅰️🅱️:func
  ns1:🅰️🅱️:func   ns1:🅰️🅱️:func

  func              ns1:🅱️:func
  b::func           ns1:🅱️:func
  ns1:🅱️:func      ns1:🅱️:func

  func              ns2::func
  ns2::func         ns2::func

Which sorted results in this:

  Table Entry       Actual symbol
  ---------------------------------
  a:🅱️:func        ns1:🅰️🅱️:func
  b::func           ns1:🅰️🅱️:func
  b::func           ns1:🅱️:func
  func              func
  func              ns1:🅰️🅱️:func
  func              ns1:🅱️:func
  func              ns2::func
  ns1:🅰️🅱️:func   ns1:🅰️🅱️:func
  ns1:🅱️:func      ns1:🅱️:func
  ns2::func         ns2::func

And we can binary search this.

Note that a binary search approach works for both completion and
regular lookup, while a name hashing approach only works for normal
symbol looking, since obviously "fun" and "func" have different
hashes.

At first I was a bit wary of these tables potentially growing GDB's
memory significantly.  But I did an experiment that convinced it's not
a worry at all.  I hacked gdb to count the total number of entries in
all the tables, attached that gdb to my system/Fedora's Firefox
(Fedora's debug packages uses .gdb_index), did "set max-completions
unlimited", and then hit "b [TAB]" to cause everything to expand.

That resulted in 1351355 name_components.  Each entry takes 8 bytes,
so that's 10810840 bytes (ignoring std::vector overhead), or ~10.3 MB.
That's IMO too small to worry about, given GDB was using over 7400MB
total at that point.  I.e., we're talking about 0.1% increase.

dw2_expand_symtabs_matching unit tests covering this will be added in
a follow up patch.

If the size of this table turns out to be a concern, I have an idea to
reduce the size of the table further at the expense of a bit more code
-- the vast majority of the name offsets are either 0 or fit in
8-bits:

 total name_component = 1351355, of which,
 name_component::name_offset instances need  0 bits = 679531
 name_component::name_offset instances need  8 bits = 669526
 name_component::name_offset instances need 16 bits = 2298
 name_component::name_offset instances need 32 bits = 0
 name_component::idx instances need 0 bits  = 51
 name_component::idx instances need 8 bits  = 8361
 name_component::idx instances need 16 bits = 280329
 name_component::idx instances need 32 bits = 1062614

so we could have separate tables for 0 name_offset, 8-bit name_offset
and 32-bit name_offset.  That'd give us roughly:

 679531 * 0 + 669526 * 1 + 2298 * 4 + 1062614 * 4 = 4929174, or ~4.7MB

with only 8-bit and 32-bit tables, that'd be:

 1349057 * 1 + 2298 * 4 + 4 * 1351355 = 6763669 bytes, or ~6.5MB.

I don't think we need to bother though.

I also timed:

 $ time gdb --batch -q -p `pidof firefox`
 $ time gdb --batch -q -p `pidof firefox` -ex "b main"
 $ time gdb --batch -q -p `pidof firefox` -ex "set max-completion unlimited" -ex "complete b "

and compared before previous patch vs this patch, and I didn't see a
significant difference, seemingly because time to read debug info
dominates.  The "complete b " variant of the test takes ~2min
currently...  (I have a follow up series that speeds that up
somewhat.)

gdb/ChangeLog:
2017-11-08  Pedro Alves  <palves@redhat.com>

	* dwarf2read.c (byte_swap, MAYBE_SWAP): Move higher up in file.
	(struct name_component): New.
	(mapped_index::name_components): New field.
	(mapped_index::symbol_name_at): New method.
	(dwarf2_read_index): Call mapped_index ctor.
	(dw2_map_matching_symbols): Add comment about name_components
	table.
	(dw2_expand_symtabs_matching): Factor part to...
	(dw2_expand_symtabs_matching_symbol): ... this new function.
	Build name components table, and lookup symbols in it before
	calling the name matcher.
	(dw2_expand_marked_cus): New, factored out from
	dw2_expand_symtabs_matching.
	(dwarf2_per_objfile_free): Call the mapped_index's dtor.
2017-11-08 16:02:24 +00:00