PR symtab/28160 and PR symtab/27893 concern GDB crashes in the test
suite when using the "fission" target board. They are both caused by
the patches that merge the list of CUs with the list of TUs (and to a
lesser degree by the patches to share DWARF data across objfiles), and
the underlying issue is the same: it turns out that reading a DWO can
cause new type units to be created. This means that the list of
dwarf2_per_cu_data objects depends on precisely which CUs have been
expanded. However, because the type units can be created while
expanding a CU means that the vector of CUs can expand while it is
being iterated over -- a classic mistake. Also, because a TU can be
added later, it means the resize_symtabs approach is incorrect.
This patch fixes resize_symtabs by removing it, and having set_symtab
resize the vector on demand. It fixes the iteration problem by
introducing a safe (index-based) iterator and changing the relevant
spots to use it.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28160
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=27893
When run with the gdb-index or debug-names target boards, dup-psym.exp
fails. This came up for me because my new DWARF scanner reuses this
part of the existing index code, and so it registers as a regression.
This is PR symtab/25834.
Looking into this, I found that the DWARF index code here is fairly
different from the psymtab code. I don't think there's a deep reason
for this, and in fact, it seemed to me that the index code could
simply mimic what the psymtab code already does.
That is what this patch implements. The DW_AT_name and DW_AT_comp_dir
are now stored in the quick file names table. This may require
allocating a quick file names table even when DW_AT_stmt_list does not
exist. Then, the functions that work with this data are changed to
use find_source_or_rewrite, just as the psymbol code does. Finally,
line_header::file_full_name is removed, as it is no longer needed.
Currently, the index maintains a hash table of "quick file names".
The hash table uses a deletion function to free the "real name"
components when necessary. There's also a second such function to
implement the forget_cached_source_info method.
This bug fix patch will create a quick file name object even when
there is no DW_AT_stmt_list, meaning that the object won't be entered
in the hash table. So, this patch changes the memory management
approach so that the entries are cleared when the per-BFD object is
destroyed. (A dwarf2_per_cu_data destructor is not introduced,
because we have been avoiding adding a vtable to that class.)
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=25834
This is another attempt at fixing the problem described in commit 4cf88725da1
"[gdb/symtab] Fix infinite recursion in dwarf2_cu::get_builder()", which was
reverted in commit 3db19b2d724.
First off, some context.
A DWARF CU can be viewed as a symbol table: toplevel children of a CU DIE
represent symbol table entries for that CU. Furthermore, there is a
hierarchy: a symbol table entry such as a function itself has a symbol table
containing parameters and local variables.
The dwarf reader maintains a notion of current symbol table (that is: the
symbol table a new symbol needs to be entered into) in dwarf2_cu member
list_in_scope.
A problem then presents itself when reading inter-CU references:
- a new symbol read from a CU B needs to be entered into the symbol table of
another CU A.
- the notion of current symbol table is tracked on a per-CU basis.
This is addressed in inherit_abstract_dies by temporarily overwriting the
list_in_scope for CU B with the one for CU A.
The current symbol table is one aspect of the current dwarf reader context
that is tracked, but there are more, f.i. ones that are tracked via the
dwarf2_cu member m_builder, f.i. m_builder->m_local_using_directives.
A similar problem exists in relation to inter-CU references, but a different
solution was chosen:
- to keep track of an ancestor field in dwarf2_cu, which is updated
when traversing inter-CU references, and
- to use the ancestor field in dwarf2_cu::get_builder to return the m_builder
in scope.
There is no actual concept of a CU having an ancestor, it just marks the most
recent CU from which a CU was inter-CU-referenced. Consequently, when
following inter-CU references from a CU A to another CU B and back to CU A,
the ancestors form a cycle, which causes dwarf2_cu::get_builder to hang or
segfault, as reported in PR26327.
ISTM that the ancestor implementation is confusing and fragile, and should
go. Furthermore, it seems that keeping track of the m_builder in scope can be
handled simply with a per-objfile variable.
Fix the hang / segfault by:
- keeping track of the m_builder in scope using a new variable
per_obj->sym_cu, and
- using it in dwarf2_cu::get_builder.
Tested on x86_64-linux (openSUSE Leap 15.2), no regressions for config:
- using default gcc version 7.5.0
(with 5 unexpected FAILs)
- gcc 10.3.0 and target board
unix/-flto/-O0/-flto-partition=none/-ffat-lto-objects
(with 1000 unexpected FAILs)
gdb/ChangeLog:
2021-06-16 Tom de Vries <tdevries@suse.de>
PR symtab/26327
* dwarf2/cu.h (dwarf2_cu::ancestor): Remove.
(dwarf2_cu::get_builder): Declare and move ...
* dwarf2/cu.c (dwarf2_cu::get_builder): ... here. Use sym_cu instead
of ancestor. Assert return value is non-null.
* dwarf2/read.c (read_file_scope): Set per_objfile->sym_cu.
(follow_die_offset, follow_die_sig_1): Remove setting of ancestor.
(dwarf2_per_objfile): Add sym_cu field.
With -fgnat-encodings=minimal, an internal version (these patches will
be upstreamed in the near future) of the Ada compiler can emit DWARF
for an array where the bound comes from a variable, like:
<1><12a7>: Abbrev Number: 7 (DW_TAG_array_type)
<12a8> DW_AT_name : (indirect string, offset: 0x1ae9): pck__my_array
[...]
<2><12b4>: Abbrev Number: 8 (DW_TAG_subrange_type)
<12b5> DW_AT_type : <0x1294>
<12b9> DW_AT_upper_bound : <0x1277>
With the upper bound DIE being:
<1><1277>: Abbrev Number: 2 (DW_TAG_variable)
<1278> DW_AT_name : (indirect string, offset: 0x1a4d): pck__my_length___U
<127c> DW_AT_type : <0x128f>
<1280> DW_AT_external : 1
<1280> DW_AT_artificial : 1
<1280> DW_AT_declaration : 1
Note that the variable is just a declaration -- in this situation, the
variable comes from another compilation unit, and must be found when
trying to compute the array bound.
This patch adds a new PROP_VARIABLE_NAME kind, to enable this search.
This same scenario can occur with DW_OP_GNU_variable_value, so this
patch adds support for that as well.
gdb/ChangeLog
2021-06-04 Tom Tromey <tromey@adacore.com>
* dwarf2/read.h (dwarf2_fetch_die_type_sect_off): Add 'var_name'
parameter.
* dwarf2/loc.c (dwarf2_evaluate_property) <case
PROP_VARIABLE_NAME>: New case.
(compute_var_value): New function.
(sect_variable_value): Use compute_var_value.
* dwarf2/read.c (attr_to_dynamic_prop): Handle DW_TAG_variable.
(var_decl_name): New function.
(dwarf2_fetch_die_type_sect_off): Add 'var_name' parameter.
* gdbtypes.h (enum dynamic_prop_kind) <PROP_VARIABLE_NAME>: New
constant.
(union dynamic_prop_data) <variable_name>: New member.
(struct dynamic_prop) <variable_name, set_variable_name>: New
methods.
gdb/testsuite/ChangeLog
2021-06-04 Tom Tromey <tromey@adacore.com>
* gdb.ada/array_of_symbolic_length.exp: New file.
* gdb.ada/array_of_symbolic_length/foo.adb: New file.
* gdb.ada/array_of_symbolic_length/gl.adb: New file.
* gdb.ada/array_of_symbolic_length/gl.ads: New file.
* gdb.ada/array_of_symbolic_length/pck.adb: New file.
* gdb.ada/array_of_symbolic_length/pck.ads: New file.
All signatured_type constucted (even those used only for lookups in hash
maps) need a signature. Enforce that by passing the signature all the
way to the signatured_type constructor.
gdb/ChangeLog:
* dwarf2/read.h (struct structured_type) <signatured_type>: New.
Update all callers.
(struct dwarf2_per_bfd) <allocate_signatured_type>: Add
signature parameter, update all callers.
* dwar2/read.c (dwarf2_per_bfd::allocate_signatured_type): Add
signature parameter.
Change-Id: I99bc1f88f54127666aa133ddbbabb7f7668fa14a
Add an alias for std::unique_ptr<signatured_type> and use it where
possible.
gdb/ChangeLog:
* dwarf2/read.h (signatured_type_up): New, use where possible.
Change-Id: I5a41e8345551434c8beeb9f269b03bdcf27989be
Move them up before dwarf2_per_bfd, this will allow adding and using
signatured_type_up in the next patch.
gdb/ChangeLog:
* dwarf2/read.h (signatured_type, dwarf2_per_cu_data): Move up.
Change-Id: I85acad4476c8236930b6f9e53ddb8bbbad009e5e
Now that CUs and TUs are stored together in all_comp_units, the
m_num_psymtabs member is no longer needed -- it is always identical to
the length of the vector. This patch removes it.
2021-05-30 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_per_bfd) <num_psymtabs,
m_num_psymtabs>: Remove.
(resize_symtabs): Update.
* dwarf2/read.c (dwarf2_per_bfd::allocate_per_cu)
(dwarf2_per_bfd::allocate_signatured_type): Update.
When loading the debug info package
libLLVM.so.10-10.0.1-lp152.30.4.x86_64.debug from openSUSE Leap 15.2, we
run into a dwarf error:
...
$ gdb -q -batch libLLVM.so.10-10.0.1-lp152.30.4.x86_64.debug
Dwarf Error: Cannot not find DIE at 0x18a936e7 \
[from module libLLVM.so.10-10.0.1-lp152.30.4.x86_64.debug]
...
The DIE @ 0x18a936e7 does in fact exist, and is part of a CU @ 0x18a23e52.
No error message is printed when using -readnow.
What happens is the following:
- a dwarf2_per_cu_data P is created for the CU.
- a dwarf2_cu A is created for the same CU.
- another dwarf2_cu B is created for the same CU.
- the dwarf2_cu B is set in per_objfile->m_dwarf2_cus, such that
per_objfile->get_cu (P) returns B.
- P->load_all_dies is set to 1.
- all dies are read into the A->partial_dies htab
- dwarf2_cu A is destroyed.
- we try to find the partial_die for the DIE @ 0x18a936e7 in B->partial_dies.
We can't find it, but do not try to load all dies, because P->load_all_dies
is already set to 1.
- an error message is generated.
The question is why we're creating dwarf2_cu A and B for the same CU.
The dwarf2_cu A is created here:
...
(gdb) bt
#0 dwarf2_cu::dwarf2_cu (this=0x79a9660, per_cu=0x23c0b30,
per_objfile=0x1ad01b0) at dwarf2/cu.c:38
#1 0x0000000000675799 in cutu_reader::cutu_reader (this=0x7fffffffd040,
this_cu=0x23c0b30, per_objfile=0x1ad01b0, abbrev_table=0x0,
existing_cu=0x0, skip_partial=false) at dwarf2/read.c:6487
#2 0x0000000000676eb3 in process_psymtab_comp_unit (this_cu=0x23c0b30,
per_objfile=0x1ad01b0, want_partial_unit=false,
pretend_language=language_minimal) at dwarf2/read.c:7028
...
And the dwarf2_cu B is created here:
...
(gdb) bt
#0 dwarf2_cu::dwarf2_cu (this=0x885e8c0, per_cu=0x23c0b30,
per_objfile=0x1ad01b0) at dwarf2/cu.c:38
#1 0x0000000000675799 in cutu_reader::cutu_reader (this=0x7fffffffcc50,
this_cu=0x23c0b30, per_objfile=0x1ad01b0, abbrev_table=0x0,
existing_cu=0x0, skip_partial=false) at dwarf2/read.c:6487
#2 0x0000000000678118 in load_partial_comp_unit (this_cu=0x23c0b30,
per_objfile=0x1ad01b0, existing_cu=0x0) at dwarf2/read.c:7436
#3 0x000000000069721d in find_partial_die (sect_off=(unknown: 0x18a55054),
offset_in_dwz=0, cu=0x0) at dwarf2/read.c:19391
#4 0x000000000069755b in partial_die_info::fixup (this=0x9096900,
cu=0xa6a85f0) at dwarf2/read.c:19512
#5 0x0000000000697586 in partial_die_info::fixup (this=0x8629bb0,
cu=0xa6a85f0) at dwarf2/read.c:19516
#6 0x00000000006787b1 in scan_partial_symbols (first_die=0x8629b40,
lowpc=0x7fffffffcf58, highpc=0x7fffffffcf50, set_addrmap=0, cu=0x79a9660)
at dwarf2/read.c:7563
#7 0x0000000000678878 in scan_partial_symbols (first_die=0x796ebf0,
lowpc=0x7fffffffcf58, highpc=0x7fffffffcf50, set_addrmap=0, cu=0x79a9660)
at dwarf2/read.c:7580
#8 0x0000000000676b82 in process_psymtab_comp_unit_reader
(reader=0x7fffffffd040, info_ptr=0x7fffc1b3f29b, comp_unit_die=0x6ea90f0,
pretend_language=language_minimal) at dwarf2/read.c:6954
#9 0x0000000000676ffd in process_psymtab_comp_unit (this_cu=0x23c0b30,
per_objfile=0x1ad01b0, want_partial_unit=false,
pretend_language=language_minimal) at dwarf2/read.c:7057
...
So in frame #9, a cutu_reader is created with dwarf2_cu A. Then a fixup takes
us to the following CU @ 0x18aa33d6, in frame #5. And a similar fixup in
frame #4 takes us back to CU @ 0x18a23e52. At that point, there's no
information available that we're already trying to read that CU, and we end up
creating another cutu_reader with dwarf2_cu B.
It seems that there are two related problems:
- creating two dwarf2_cu's is not optimal
- the unoptimal case is not handled correctly
This patch addresses the last problem, by moving the load_all_dies flag from
dwarf2_per_cu_data to dwarf2_cu, such that it is paired with the partial_dies
field, which ensures that the two can be kept in sync.
Tested on x86_64-linux.
gdb/ChangeLog:
2021-05-27 Tom de Vries <tdevries@suse.de>
PR symtab/27898
* dwarf2/cu.c (dwarf2_cu::dwarf2_cu): Add load_all_dies init.
* dwarf2/cu.h (dwarf2_cu): Add load_all_dies field.
* dwarf2/read.c (load_partial_dies, find_partial_die): Update.
* dwarf2/read.h (dwarf2_per_cu_data::dwarf2_per_cu_data): Remove
load_all_dies init.
(dwarf2_per_cu_data): Remove load_all_dies field.
Simon pointed out that dwarf2/cu.h and dwarf2/comp-unit.h seemingly
mean the same thing. He suggested renaming the latter to
comp-unit-head.h, which is what this patch does.
gdb/ChangeLog
2021-05-17 Tom Tromey <tom@tromey.com>
* dwarf2/read.h: Update include.
* dwarf2/read.c: Update include.
* dwarf2/line-header.c: Update include.
* dwarf2/cu.h: Update include.
* dwarf2/comp-unit-head.h: Rename from comp-unit.h.
* dwarf2/comp-unit-head.c: Rename from comp-unit.c.
* Makefile.in (COMMON_SFILES): Update.
Address sanitizer pointed out that the patch to use 'delete' for
dwarf2_per_cu_data introduced a bug -- now it is possible to delete a
signatured_type using a pointer to its base class.
This patch fixes the problem by introducing a deleter and a unique_ptr
specialization. A virtual destructor would be more ordinary here, but
it seemed wasteful to add a vtable just for this purpose. If virtual
methods are ever needed here, we can revisit this.
2021-05-17 Tom Tromey <tromey@adacore.com>
* dwarf2/read.h (struct dwarf2_per_cu_data_deleter: New.
(dwarf2_per_cu_data_up): New typedef.
(struct dwarf2_per_bfd) <allocate_per_cu>: Change return type.
<all_comp_units>: Use dwarf2_per_cu_data_up.
* dwarf2/read.c (dwarf2_per_cu_data::operator()): New function.
(dwarf2_per_bfd::allocate_per_cu): Return dwarf2_per_cu_data_up.
(create_cu_from_index_list): Likewise.
(create_signatured_type_table_from_index)
(create_cus_from_debug_names_list, add_type_unit)
(read_comp_units_from_section): Update.
(dwarf2_find_containing_comp_unit): Change type of all_comp_units.
(run_test): Update.
I don't think there is any deep reason to separate CUs and TUs in
dwarf2_per_bfd. This patch removes all_type_units and unifies these
two containers. Some minor tweaks are needed to the index writers,
because both forms of index keep CUs and TUs separate;
Regression tested on x86-63 Fedora 32.
gdb/ChangeLog
2021-04-30 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct tu_stats) <nr_tus>: New member.
(struct dwarf2_per_bfd) <get_cutu, get_tu>: Remove
<get_cu>: Now inline.
<all_type_units>: Remove.
* dwarf2/read.c (dwarf2_per_bfd::~dwarf2_per_bfd): Update.
(dwarf2_per_bfd::get_cutu, dwarf2_per_bfd::get_cu)
(dwarf2_per_bfd::get_tu): Remove.
(dwarf2_per_bfd::allocate_signatured_type): Update nr_tus.
(create_signatured_type_table_from_index)
(create_signatured_type_table_from_debug_names)
(dw2_symtab_iter_next, dwarf2_base_index_functions::print_stats)
(dwarf2_base_index_functions::expand_all_symtabs)
(dw2_expand_marked_cus, dw_expand_symtabs_matching_file_matcher)
(dwarf2_base_index_functions::map_symbol_filenames)
(dw2_debug_names_iterator::next, dwarf2_initialize_objfile)
(add_signatured_type_cu_to_table, create_all_type_units)
(add_type_unit, build_type_psymtabs_1, print_tu_stats)
(create_all_comp_units): Update.
* dwarf2/index-write.c (check_dwarf64_offsets, write_gdbindex)
(write_debug_names): Update.
In a patch series I am working on, I'd like to have a non-POD member
in dwarf2_per_cu_data. This currently can't be done because
dwarf2_per_cu_data is allocated on an obstack and initialized with
memset.
This patch changes the DWARF reader to allocate objects of this type
with 'new'. The various "subclasses" of this type (signatured_type in
particular) are now changed to derive from dwarf2_per_cu_data, and
also use 'new' for allocation.
Regression tested on x86-64 Fedora 32.
gdb/ChangeLog
2021-04-30 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_per_bfd) <allocate_per_cu,
allocate_signatured_type>: Change return type.
<all_comp_units, all_type_units>: Hold unique pointers.
(struct dwarf2_per_cu_data): Add constructor and initializers.
(struct signatured_type): Derive from dwarf2_per_cu_data.
* dwarf2/read.c (type_unit_group): Derive from
dwarf2_per_cu_data.
(dwarf2_per_bfd::get_cutu, dwarf2_per_bfd::get_cu)
(dwarf2_per_bfd::get_tu)
(dwarf2_per_bfd::allocate_signatured_type)
(dwarf2_per_bfd::allocate_signatured_type)
(create_cu_from_index_list, create_cus_from_index_list)
(create_signatured_type_table_from_index)
(create_signatured_type_table_from_debug_names)
(create_addrmap_from_aranges)
(dwarf2_base_index_functions::find_last_source_symtab)
(dw_expand_symtabs_matching_file_matcher)
(dwarf2_gdb_index::expand_symtabs_matching)
(dwarf2_base_index_functions::map_symbol_filenames)
(create_cus_from_debug_names_list)
(dw2_debug_names_iterator::next)
(dwarf2_debug_names_index::expand_symtabs_matching)
(create_debug_type_hash_table, add_type_unit)
(fill_in_sig_entry_from_dwo_entry, lookup_dwo_signatured_type):
Update.
(allocate_type_unit_groups_table): Use delete.
(create_type_unit_group): Change return type. Use new.
(get_type_unit_group, build_type_psymtabs_1)
(build_type_psymtab_dependencies)
(process_skeletonless_type_unit, set_partial_user)
(dwarf2_build_psymtabs_hard, read_comp_units_from_section)
(create_cus_hash_table, queue_and_load_dwo_tu, follow_die_sig_1)
(read_signatured_type): Update.
(dwarf2_find_containing_comp_unit): Change type of
'all_comp_units'.
(run_test): Update.
(dwarf2_per_bfd::allocate_per_cu)
(dwarf2_per_bfd::allocate_signatured_type): Change return type.
Use new.
(add_signatured_type_cu_to_table): Update.
* dwarf2/index-write.c (write_one_signatured_type)
(check_dwarf64_offsets, psyms_seen_size, write_gdbindex)
(write_debug_names): Update.
While working on some changes to 'info sources' I ran into a situation
where I was seeing the same source files reported twice in the output
of the 'info sources' command when using either .gdb_index or the
.debug_name index.
I traced the problem back to some caching in
dwarf2_base_index_functions::map_symbol_filenames; when called GDB
caches the set of filenames, but, filesnames are not removed as the
index entries are expanded into full symtabs. As a result we can end
up seeing filenames reported both from a full symtab _and_ from
a (stale) previously cached index entry.
Now, obviously, when seeing a problem like this the "correct" fix is
to remove the stale entries from the cache, however, I ran a few
experiments to see why this wasn't really hitting us anywhere, and, as
far as I can tell, ::map_symbol_filenames is only called from three
places:
1. The mi command -file-list-exec-source-files,
2. The 'info sources' command, and
3. Filename completion
However, the result of this "bug" is that we will see duplicate
filenames, and readline's completion mechanism already removes
duplicates, so for case #3 we will never see any problems.
Cases #1 and #2 are basically the same, and in each case, to see a
problem we need to ensure we craft the test in a particular way, start
up ensuring we have some unexpected symtabs, then run one of the
commands to populate the cache, then expand one of the symtabs, and
list the sources again. At this point you'll see duplicate entries in
the results. Hardly surprising we haven't randomly hit this situation
in testing.
So, considering that use cases #1 and #2 are certainly not "high
performance" code (i.e. I don't think these justify the need for
caching) this leaves use case #3. Does this use justify the need for
caching? Well the psymbol_functions::map_symbol_filenames function
doesn't seem to do any extra caching, and within
dwarf2_base_index_functions::map_symbol_filenames, the only expensive
bit appears to be the call to dw2_get_file_names, and this already
does its own caching via this_cu->v.quick->file_names.
The upshot of all this analysis was that I'm not convinced the need
for the additional caching is justified, and so, I propose that to fix
the bug in GDB, I just remove the extra caching (for now).
If we later find that the caching _was_ useful, then we can
reintroduce it, but add it back such that it doesn't reintroduce this
bug.
As I was changing dwarf2_base_index_functions::map_symbol_filenames I
replaced the use of htab_up with std::unordered_set.
Tested using target_boards cc-with-debug-names and dwarf4-gdb-index.
gdb/ChangeLog:
* dwarf2/read.c: Add 'unordered_set' include.
(dwarf2_base_index_functions::map_symbol_filenames): Replace
'visited' hash table with 'qfn_cache' unordered_set. Remove use
of per_Bfd->filenames_cache cache, and use function local
filenames_cache instead. Reindent.
* dwarf2/read.h (struct dwarf2_per_bfd) <filenames_cache>: Delete.
gdb/testsuite/ChangeLog:
* gdb.base/info_sources.exp: Add new tests.
I noticed some holes in struct dwarf2_per_cu_data. This patch
rearranges the type slightly, and shrinks the size of some fields.
This reduces it from 136 bytes to 112 bytes (on x86-64).
I also reduced the size of the DWARF "version" fields in a couple of
spots. It seemed needless to use a short to hold a value that ranges
from 2 to 5, and this also helped the goal of shrinking
dwarf2_per_cu_data.
2021-04-21 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_per_cu_data) <dwarf_version>: Now
unsigned char.
(struct dwarf2_per_cu_data): Rearrange.
* dwarf2/comp-unit.h (struct comp_unit_head) <version>: Now
unsigned char.
(struct comp_unit_head): Rearrange.
* dwarf2/comp-unit.c (read_comp_unit_head): Update.
Since partial_symtab is supposed to be objfile-independent (since series
[1]), I think it would make sense for partial_symtab to not take an
objfile as a parameter in its constructor.
This patch replaces that parameter with an objfile_per_bfd_storage
parameter.
The objfile is used for two things:
- to get the objfile_name, for debug messages. We can get that name
from the bfd instead.
- to intern the partial symtab filename. Even though it goes through
an objfile method, the request is actually forwarded to the
underlying objfile_per_bfd_storage. So we can ask the new
objfile_per_bfd_storage instead.
In order to get a reference to the BFD from the objfile_per_bfd_storage,
the BFD is saved in the objfile_per_bfd_storage object.
[1] https://sourceware.org/pipermail/gdb-patches/2021-February/176625.html
gdb/ChangeLog:
* psympriv.h (struct partial_symtab) <partial_symtab>: Change
objfile parameter for objfile_per_bfd_storage, adjust callers.
(struct standard_psymtab) <standard_psymtab>: Likewise.
(struct legacy_psymtab) <legacy_psymtab>: Likewise.
* psymtab.c (partial_symtab::partial_symtab): Likewise.
* ctfread.c (struct ctf_psymtab): Likewise.
* dwarf2/read.h (struct dwarf2_psymtab): Likewise.
* dwarf2/read.c (struct dwarf2_include_psymtab): Likewise.
(dwarf2_create_include_psymtab): Likewise.
* objfiles.h (struct objfile_per_bfd_storage)
<objfile_per_bfd_storage>: Add bfd parameter, adjust callers.
<get_bfd>: New method.
<m_bfd>: New field.
* objfiles.c (get_objfile_bfd_data): Adjust.
Change-Id: I2ed3ab5d2e6f27d034bd4dc26ae2fae7b0b8a2b9
Currently the DWARF index readers reuse the objfile's partial symbol
table in order to store an addrmap. We're going to be remove the
partial symbol object, so this patch changes the DWARF reader to store
this addrmap in the per_bfd object. This object is chosen, rather
than the quick_symbol_functions subclass, because the addrmap can be
shared across objfiles.
gdb/ChangeLog
2021-03-20 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_per_bfd) <psymtabs_addrmap>: New
member.
* dwarf2/read.c (create_addrmap_from_index)
(create_addrmap_from_aranges): Set per_bfd addrmap.
(dwarf2_read_gdb_index): Don't set partial_symtabs.
(dwarf2_base_index_functions::find_pc_sect_compunit_symtab): Use
per_bfd addrmap.
(dwarf2_read_debug_names): Don't set partial_symtabs.
(dwarf2_initialize_objfile): Likewise.
This moves a bit of the DWARF-specific code out of symfile.h and into
dwarf2/read.h.
gdb/ChangeLog
2021-03-20 Tom Tromey <tom@tromey.com>
* symfile.h (enum dwarf2_section_enum)
(dwarf2_get_section_info): Move to dwarf2/read.h.
* dwarf2/read.h (enum dwarf2_section_enum)
(dwarf2_get_section_info): Move from symfile.h.
This moves dwarf2_get_dwz_file and some helper code to dwarf2/dwz.h.
The main benefit of this is just shrinking dwarf2/read.c a little bit.
gdb/ChangeLog
2021-03-06 Tom Tromey <tom@tromey.com>
* dwarf2/sect-names.h (dwarf2_elf_names): Declare.
* dwarf2/read.h (dwarf2_get_dwz_file): Move to dwz.h.
* dwarf2/read.c (dwarf2_elf_names): No longer static.
(locate_dwz_sections, dwz_search_other_debugdirs)
(dwarf2_get_dwz_file): Move to dwz.c.
* dwarf2/dwz.h (dwarf2_get_dwz_file): Move declaration from
read.h.
* dwarf2/dwz.c (locate_dwz_sections, dwz_search_other_debugdirs)
(dwarf2_get_dwz_file): Move from read.c.
If DWARF contains a reference to a "dwz" file, but there is no
.gnu_debugaltlink section, then gdb will crash. This happens because
dwarf2_get_dwz_file will return NULL, but some callers do not expect
this.
This patch changes dwarf2_get_dwz_file so that callers can require a
dwz file. Then, it updates the callers that are attempting to process
references to the dwz file to require one.
This includes a new testcase. The dwarf.exp changes don't handle the
new forms exactly correctly -- they are only handled well enough to
let this test case complete.
gdb/ChangeLog
2021-03-06 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (dwarf2_get_dwz_file): Add 'require' parameter.
* dwarf2/read.c (dwarf2_get_dwz_file): Add 'require' parameter.
(get_abbrev_section_for_cu, read_attribute_value)
(get_debug_line_section): Update.
* dwarf2/macro.c (dwarf_decode_macro_bytes): Update.
gdb/testsuite/ChangeLog
2021-03-06 Tom Tromey <tom@tromey.com>
* lib/dwarf.exp (_handle_DW_FORM): Treat DW_FORM_GNU_ref_alt and
DW_FORM_GNU_strp_alt like DW_FORM_sec_offset.
* gdb.dwarf2/dwznolink.exp: New file.
As described in the log of patch "gdb/dwarf: add assertion in
maybe_queue_comp_unit", it would happen that a call to
maybe_queue_comp_unit would enqueue a CU in the to-expand queue while
nothing up the stack was processing the queue. This is not desirable,
as items are then left lingering in the queue when we exit the
dwarf2/read code. This is an inconsistent state.
The normal case of using the queue is when we go through
dw2_do_instantiate_symtab and process_queue. As depended-on CUs are
found, they get added to the queue. process_queue expands CUs until the
queue is empty.
To catch these cases where things are enqueued while nothing up the
stack is processing the queue, change dwarf2_per_bfd::queue to be an
optional. The optional is instantiated in dwarf2_queue_guard, just
before where we call process_queue. In the dwarf2_queue_guard
destructor, the optional gets reset. Therefore, the queue object is
instantiated only when something up the stack is handling it. If
another entry point tries to enqueue a CU for expansion, an assertion
will fail and we know we have something to fix.
dwarf2_queue_guard sounds like the good place for this, as it's
currently responsible for making sure the queue gets cleared if we exit
due to an error.
This also allows asserting that when age_comp_units or remove_all_cus
run, the queue is not instantiated, and gives us one more level of
assurance that we won't free the DIEs of a CU that is in the
CUs-to-expand queue.
gdb/ChangeLog:
PR gdb/26828
* dwarf2/read.c (dwarf2_queue_guard) <dwarf2_queue_guard>:
Instantiate queue.
(~dwarf2_queue_guard): Clear queue.
(queue_comp_unit): Assert that queue is
instantiated.
(process_queue): Adjust.
* dwarf2/read.h (struct dwarf2_per_bfd) <queue>: Make optional.
Change-Id: I8fe3d77845bb4ad3d309eac906acebe79d9f0a9d
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
Replace the function pointer + `void *` parameters of
dwarf2_fetch_die_loc_sect_off and dwarf2_fetch_die_loc_cu_off with a
function_view parameter. Change call sites to use a lambda function.
This improves type-safety, so reduces the chances of errors.
gdb/ChangeLog:
* read.h (dwarf2_fetch_die_loc_sect_off,
dwarf2_fetch_die_loc_cu_off): Replace function pointer +
`void *` parameter with function_view.
* read.c (dwarf2_fetch_die_loc_sect_off,
dwarf2_fetch_die_loc_cu_off): Likewise.
* loc.c (get_frame_pc_for_per_cu_dwarf_call): Remove.
(per_cu_dwarf_call): Adjust.
(get_frame_address_in_block_wrapper): Remove.
(indirect_synthetic_pointer): Adjust.
(get_ax_pc): Remove.
(dwarf2_compile_expr_to_ax): Adjust.
Change-Id: Ic9b6ced0c4128f2b75ca62e0ed638b0962a22859
While doing the psymtab-sharing patchset, I avoided renaming variables
unnecessarily to avoid adding noise to patches, but I'd like to do it
now. Basically, we have these dwarf2 per-something structures:
- dwarf2_per_objfile
- dwarf2_per_bfd
- dwarf2_per_cu_data
I named the instances of dwarf2_per_bfd `per_bfd` and most of instances
of dwarf2_per_cu_data are called `per_cu`. Most pre-existing instances
of dwarf2_per_objfile are named `dwarf2_per_objfile`. For consistency
with the other type, I'd like to rename them to just `per_objfile`. The
`dwarf2_` prefix is superfluous, since it's already clear we are in
dwarf2 code. It also helps reducing the line wrapping by saving 7
precious columns.
gdb/ChangeLog:
* dwarf2/comp-unit.c, dwarf2/comp-unit.h, dwarf2/index-cache.c,
dwarf2/index-cache.h, dwarf2/index-write.c,
dwarf2/index-write.h, dwarf2/line-header.c,
dwarf2/line-header.h, dwarf2/macro.c, dwarf2/macro.h,
dwarf2/read.c, dwarf2/read.h: Rename struct dwarf2_per_objfile
variables and fields from `dwarf2_per_objfile` to just
`per_objfile` throughout.
Change-Id: I3c45cdcc561265e90df82cbd36b4b4ef2fa73aef
This changes the DWARF reader to share partial symtabs (or indices if
they are available) across objfiles. This has a few parts.
* If multiple objfiles backed by the same BFD can share partial symtabs
(see below), a single dwarf2_per_bfd is created. It is stored in the
per-bfd `dwarf2_per_bfd_bfd_data_key` registry. Multiple
dwarf2_per_objfile objects will point to the same instance. The
lifetime of these dwarf2_per_bfd objects is naturally handled. When
all the objfiles using the BFD are destroyed, the BFD's refount drops
to 0, which triggers the removal of the corresponding dwarf2_per_bfd
object from the registry and its destruction.
* If multiple objfiles backed by the same BFD can't share partial
symtabs (see below), one dwarf2_per_bfd object is created for each
objfile. Each dwarf2_per_objfile will point to their own instance of
dwarf2_per_bfd. These instances of dwarf2_per_bfd are kept in a
per-objfile registry, meaning that when the objfile gets destroyed,
the dwarf2_per_bfd instance gets destroyed as well.
* objfile::partial_symtabs is changed to be a shared_ptr again. This
lets us stash a second reference in dwarf2_per_bfd; if the DWARF
data is being shared, we can simply copy this value to the new
objfile.
* Two dwarf2_per_objfile objects backed by the same BFD may share a
dwarf2_per_bfd instance if:
* No other symbol reader has found symbols, and
* No BFD section rqeuires relocation
gdb/ChangeLog:
YYYY-MM-DD Tom Tromey <tom@tromey.com>
YYYY-MM-DD Simon Marchi <simon.marchi@efficios.com>
* objfiles.h (struct objfile) <partial_symtabs>: Now a
shared_ptr.
* dwarf2/read.h (struct dwarf2_per_objfile) <partial_symtabs>: New
member.
* dwarf2/read.c (dwarf2_per_bfd_bfd_data_key,
dwarf2_per_bfd_objfile_data_key>: New globals.
(dwarf2_has_info): Use shared dwarf2_per_bfd if possible.
(dwarf2_get_section_info): Use get_dwarf2_per_objfile.
(dwarf2_initialize_objfile): Consider cases where per_bfd can be
shared.
(dwarf2_build_psymtabs): Set objfile::partial_symtabs and
short-circuit when sharing.
(dwarf2_build_psymtabs): Set dwarf2_per_objfile::partial_symtabs.
(dwarf2_psymtab::expand_psymtab): Use free_cached_comp_units.
Change-Id: I868c64448589102ab8cbb8f06c31a8de50a14004
The `line_header_hash` field of `struct dwarf2_per_bfd` contains some
`struct line_header` objects. A `struct line_header` objects contains
some `file_entry` objects. A `file_entry` object contains a pointer to
the `symtab` object created from it. The `line_header_hash` is
therefore ultimately objfile-dependent and can't be shared as-is between
objfiles.
Move it from `dwarf2_per_bfd` to `dwarf2_per_objfile`.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_bfd) <line_header_hash>: Move
to...
(struct dwarf2_per_objfile) <line_header_hash>: ... here.
* dwarf2/read.c (handle_DW_AT_stmt_list): Update.
Change-Id: I8d2ee04df4f4847c2db99061fc976c35af98ac71
The dwarf2_per_cu_data type is going to become objfile-independent,
while the dwarf2_cu type will stay object-dependent. This patch removes
the backlink from dwarf2_per_cu_data to dwarf2_cu, in favor of the
dwarf2_per_objfile::m_dwarf2_cus map. It maps dwarf2_per_cu_data
objects to the corresponding dwarf2_cu objects for this objfile. If a
CU has been read in in the context of this objfile, then an entry will
be present in the map.
The dwarf2_cu objects that are read in are currently kept in a linked
list rooted in the dwarf2_per_bfd. Except that the dwarf2_cu objects
are not simply linked together, they are interleaved with their
corresponding dwarf2_per_cu_data objects. So if we have CUs A and B
read in, the dwarf2_per_bfd::read_in_chain will point to a chain like
this (DPCD == dwarf2_per_cu_data, DC == dwarf2_cu):
DPCD A -> DC A -> DPCD B -> DC B
Obviously, this can't stay as is, since a same CU can be read in for an
objfile but not read in for another objfile sharing the same BFD, and
the dwarf2_per_cu_data::cu link is removed. This is all replaced by
the dwarf2_per_objfile::m_dwarf2_cus map.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_cu): Forward-declare.
(struct dwarf2_per_bfd) <free_cached_comp_units>: Remove,
move to dwarf2_per_objfile.
<read_in_chain>: Remove.
(struct dwarf2_per_objfile) <get_cu, set_cu, remove_cu,
remove_all_cus, age_comp_units>: New methods.
<m_dwarf2_cus>: New member.
(struct dwarf2_per_cu_data) <cu>: Remove.
* dwarf2/read.c (struct dwarf2_cu) <read_in_chain>: Remove.
(age_cached_comp_units, free_one_cached_comp_unit): Remove,
moved to methods of dwarf2_per_objfile.
(dwarf2_clear_marks): Remove.
(dwarf2_queue_item::~dwarf2_queue_item): Update.
(dwarf2_per_bfd::~dwarf2_per_bfd): Don't free dwarf2_cus.
(dwarf2_per_bfd::free_cached_comp_units): Remove.
(dwarf2_per_objfile::remove_all_cus): New.
(class free_cached_comp_units) <~free_cached_comp_units>:
Update.
(load_cu): Update.
(dw2_do_instantiate_symtab): Adjust.
(fill_in_sig_entry_from_dwo_entry): Adjust.
(cutu_reader::init_tu_and_read_dwo_dies): Update.
(cutu_reader::cutu_reader): Likewise.
(cutu_reader::keep): Use dwarf2_per_objfile::set_cu.
(cutu_reader::cutu_reader): Use dwarf2_per_objfile::get_cu.
(process_psymtab_comp_unit): Use dwarf2_per_objfile::remove_cu
and dwarf2_per_objfile::age_comp_units.
(load_partial_comp_unit): Update.
(maybe_queue_comp_unit): Use dwarf2_per_objfile::get_cu.
(process_queue): Likewise.
(find_partial_die): Use dwarf2_per_objfile::get_cu instead of cu
backlink.
(dwarf2_read_addr_index): Likewise.
(follow_die_offset): Likewise.
(dwarf2_fetch_die_loc_sect_off): Likewise.
(dwarf2_fetch_constant_bytes): Likewise.
(dwarf2_fetch_die_type_sect_off): Likewise.
(follow_die_sig_1): Likewise.
(load_full_type_unit): Likewise.
(read_signatured_type): Likewise.
(dwarf2_cu::dwarf2_cu): Don't set cu field.
(dwarf2_cu::~dwarf2_cu): Remove.
(dwarf2_per_objfile::get_cu): New.
(dwarf2_per_objfile::set_cu): New.
(age_cached_comp_units): Rename to...
(dwarf2_per_objfile::age_comp_units): ... this. Adjust
to std::unordered_map.
(free_one_cached_comp_unit): Rename to...
(dwarf2_per_objfile::remove_cu): ... this. Adjust
to std::unordered_map.
(dwarf2_per_objfile::~dwarf2_per_objfile): New.
(dwarf2_mark_helper): Use dwarf2_per_objfile::get_cu, expect
a dwarf2_per_objfile in data.
(dwarf2_mark): Pass dwarf2_per_objfile in data to htab_traverse.
(dwarf2_clear_marks): Remove.
Change-Id: Ia33ac71c79b2de4710569008e22a6563a1505cde
The per_cu_header_read_in function allows obtaining a filled
comp_unit_head object for a given dwarf2_per_cu_data object. If a
dwarf2_cu object exists for this dwarf2_per_cu_data, then it just
returns a pointer to the comp_unit_head from that dwarf2_cu. Otherwise,
it reads the header into a temporary buffer provided by the caller, and
returns a pointer to that.
Since the dwarf2_per_cu_data::cu link is going to be removed
(dwarf2_per_cu_data will become objfile-independent while dwarf2_cu
stays objfile-dependent), we cannot rely anymore on returning the header
from the dwarf2_cu object.
The not too complex solution implemented by this patch is to keep a copy
of the header in the dwarf2_per_cu_data object, independent from the
copy in dwarf2_cu. The new copy is only used in the addr_size,
offset_size and ref_addr_size methods of dwarf2_per_cu_data.
There's nothing intrinsic to the comp_unit_head object that prevents it
to be shared between two dwarf2_cu objects (belonging to different
objfiles) representing the same CU. In other words, I think we could
eventually get rid of the copy in dwarf2_cu to only keep the one in
dwarf2_per_cu_data. It is not trivial, however, so I have decided not
to do it for the moment.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_cu_data) <m_header,
m_header_read_in>: New fields.
<get_header>: New method.
* dwarf2/read.c (per_cu_header_read_in): Remove.
(dwarf2_per_cu_data::get_header): New.
(dwarf2_per_cu_data::addr_size): Update.
(dwarf2_per_cu_data::offset_size): Update.
(dwarf2_per_cu_data::ref_addr_size): Update.
Change-Id: Id7541fca7562843eba110ece21c4df38d45fca23
signatured_type has a link to the "struct type". However, types are
inherently objfile-specific, so once sharing is implemented, this will
be incorrect.
This patch moves the type to a new map in the DWARF unshareable
object.
gdb/ChangeLog:
YYYY-MM-DD Tom Tromey <tom@tromey.com>
YYYY-MM-DD Simon Marchi <simon.marchi@efficios.com>
* dwarf2/read.h (struct dwarf2_per_objfile)
<get_type_for_signatured_type, set_type_for_signatured_type>:
New methods.
<m_type_map>: New member.
(struct signatured_type) <type>: Remove.
* dwarf2/read.c
(dwarf2_per_objfile::get_type_for_signatured_type,
dwarf2_per_objfile::set_type_for_signatured_type): New.
(get_signatured_type): Use new methods.
Change-Id: I765ae3c43fae1064f51ced352167a57638609f02
type_unit_group has links to the compunit_symtab and other symtabs.
However, once this object is shared across objfiles, this will no
longer be ok.
This patch introduces a new type_unit_group_unshareable and arranges to
store a map from type unit groups to type_unit_group_unshareable objects
in dwarf2_per_objfile.
gdb/ChangeLog:
YYYY-MM-DD Tom Tromey <tom@tromey.com>
YYYY-MM-DD Simon Marchi <simon.marchi@efficios.com>
* dwarf2/read.h (struct type_unit_group_unshareable): New.
(struct dwarf2_per_objfile) <type_units>: New member.
<get_type_unit_group_unshareable>: New method.
* dwarf2/read.c (struct type_unit_group) <compunit_symtab,
num_symtabs, symtabs>: Remove; move to
type_unit_group_unshareable.
(dwarf2_per_objfile::get_type_unit_group_unshareable): New.
(process_full_type_unit, dwarf2_cu::setup_type_unit_groups)
(dwarf2_cu::setup_type_unit_groups): Use type_unit_group_unshareable.
Change-Id: I1fec2fab59e0ec40fee3614fc821172a469c0e41
Since dwarf2_per_cu_data objects are going to become
objfile-independent, the backlink from dwarf2_per_cu_data to one
particular objfile must be removed. Instead, users of
dwarf2_per_cu_data that need an objfile must know from somewhere else in
the context of which objfile they are using this CU.
This also helps remove a dwarf2_per_cu_data::dwarf2_per_objfile
reference (from where the objfile was obtained).
Note that the dwarf2_per_cu_data::objfile method has a special case to
make sure to return the main objfile, if the objfile associated to the
dwarf2_per_cu_data is a separate debug objfile. I don't really know if
this is necessary: I ignored that, and didn't see any regression when
testing with the various Dejagnu boards with separate debug info, so I
presume it wasn't needed. If it turns out this was needed, then we can
have a helper method on the objfile type for that.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_cu_data) <objfile>: Remove.
* dwarf2/read.c (dwarf2_compute_name): Pass per_objfile down.
(read_call_site_scope): Assign per_objfile.
(dwarf2_per_cu_data::objfile): Remove.
* gdbtypes.h (struct call_site) <per_objfile>: New member.
* dwarf2/loc.h (dwarf2_evaluate_loc_desc): Add
dwarf2_per_objfile parameter.
* dwarf2/loc.c (dwarf2_evaluate_loc_desc_full): Add
dwarf2_per_objfile parameter.
(dwarf_expr_reg_to_entry_parameter): Add output
dwarf2_per_objfile parameter.
(locexpr_get_frame_base): Update.
(class dwarf_evaluate_loc_desc) <get_tls_address>: Update.
<push_dwarf_reg_entry_value>: Update.
<call_site_to_target_addr>: Update.
(dwarf_entry_parameter_to_value): Add dwarf2_per_objfile
parameter.
(value_of_dwarf_reg_entry): Update.
(rw_pieced_value): Update.
(indirect_synthetic_pointer): Update.
(dwarf2_evaluate_property): Update.
(dwarf2_loc_desc_get_symbol_read_needs): Add dwarf2_per_objfile
parameter.
(locexpr_read_variable): Update.
(locexpr_get_symbol_read_needs): Update.
(loclist_read_variable): Update.
Change-Id: Idb40d1a94995af305054d463967bb6ce11a08f25
This method simply returns the text offset of the objfile associated to
the dwarf2_per_cu_data object. Since dwarf2_per_cu_data objects are
going to become objfile-independent, we can't keep this method. This
patch removes it.
Existing callers need to figure out the in the context of which objfile
this is being used, and call text_offset on it. Typically, this comes
from a symbol baton, where we store the corresponding
dwarf2_per_objfile.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_cu_data) <text_offset>:
Remove.
* dwarf2/read.c (dwarf2_per_cu_data::text_offset): Remove.
* dwarf2/loc.c (dwarf2_find_location_expression): Update.
(dwarf2_compile_property_to_c): Update.
(dwarf2_compile_expr_to_ax): Add dwarf2_per_objfile parameter,
use text offset from objfile.
(locexpr_tracepoint_var_ref): Update.
(locexpr_generate_c_location): Update.
(loclist_describe_location): Update.
(loclist_tracepoint_var_ref): Update.
* dwarf2/compile.h (compile_dwarf_bounds_to_c): Add
dwarf2_per_objfile parameter.
* dwarf2/loc2c.c (do_compile_dwarf_expr_to_c): Likewise,
use text offset from objfile.
(compile_dwarf_expr_to_c): Add dwarf2_per_objfile parameter.
Change-Id: I56b01ba294733362a3562426a96d48ae051a776f
These methods rely on the current objfile to create types based on it.
Since dwarf2_per_cu_data is to become objfile-independent, these methods
need to mvoe.
int_type can be in dwarf2_per_objfile, as it only requires knowing about
the objfile.
addr_sized_int_type and addr_type also need to know about the DWARF
address type size, which is CU-specific. The dwarf2_cu objects seems
like a good place for it, as it knows both about the current objfile and
the current CU.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_cu_data) <addr_type,
addr_sized_int_type>: Move to dwarf2_cu.
<int_type>: Move to dwarf2_per_objfile.
(struct dwarf2_per_objfile) <int_type>: Move here.
* dwarf2/read.c (struct dwarf2_cu) <addr_type,
addr_sized_int_type>: Move here.
(read_func_scope): Update.
(read_array_type): Update.
(read_tag_string_type): Update.
(attr_to_dynamic_prop): Update.
(dwarf2_per_cu_data::int_type): Rename to...
(dwarf2_per_objfile::int_type): ... this.
(dwarf2_per_cu_data::addr_sized_int_type): Rename to...
(dwarf2_cu::addr_sized_int_type): ... this.
(read_subrange_type): Update.
(dwarf2_per_cu_data::addr_type): Rename to...
(dwarf2_cu::addr_type): ... this.
(set_die_type): Update.
Change-Id: Ic4708ef99d43a8d99325ff91dee59b2eb706cb8f
This allows removing a per_bfd->dwarf2_per_objfile reference in
get_abbrev_section_for_cu.
This requires saving the bfd in dwarf2_per_bfd. The constructor of
dwarf2_per_bfd already accepts the bfd, so it's just a matter of saving
it in a field.
I replaced uses of objfile_name with bfd_get_filename, which should be
equivalent in this case.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_bfd) <obfd>: New member.
(dwarf2_get_dwz_file): Replace parameter with dwarf2_per_bfd.
* dwarf2/read.c (dwarf2_per_bfd::dwarf2_per_bfd): Assign obfd
field.
(dwarf2_get_dwz_file): Replace parameter with dwarf2_per_bfd.
(create_cus_from_index): Update.
(dwarf2_read_gdb_index): Update.
(create_cus_from_debug_names): Update.
(dwarf2_read_debug_names): Update.
(get_abbrev_section_for_cu): Update.
(create_all_comp_units): Update.
(read_attribute_value): Update.
(get_debug_line_section): Update.
* dwarf2/index-cache.c (index_cache::store): Update.
* dwarf2/index-write.c (save_gdb_index_command): Update.
* dwarf2/macro.c (dwarf_decode_macro_bytes): Update.
Change-Id: Ifb23f55dda93c499aae57b6a9aff9c6ff9d2f45f
Some code using dwarf2_per_cu_data objects accesses the corresponding
dwarf2_per_bfd using the following pattern:
per_cu->dwarf2_per_objfile->per_bfd
Since dwarf2_per_cu_data objects are going to become
objfile-independent, the dwarf2_per_objfile link must go. To replace
it, add a dwarf2_per_cu_data->per_bfd link. It makes sense to have it
there because the dwarf2_per_cu_data objects belong to the
dwarf2_per_bfd, so this is essentially just a backlink to their owner.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_cu_data) <per_bfd>: New
member.
* dwarf2/read.c (dwarf2_per_bfd::allocate_per_cu): Initialize
dwarf2_per_cu_data::per_bfd.
(dwarf2_per_bfd::allocate_signatured_type): Likewise.
(create_type_unit_group): Likewise.
(queue_comp_unit): Remove reference to
per_cu->dwarf2_per_objfile.
(maybe_queue_comp_unit): Likewise.
(fill_in_sig_entry_from_dwo_entry): Assign new field.
(create_cus_hash_table): Assign new field.
Change-Id: I4ba0a393e64a14489ef061261a3dede1509d055b
The die_type_hash field can't be shared between multiple obfiles, as it
holds `struct type` objects, which are objfile-specific. Move it from
dwarf2_per_bfd to dwarf2_per_objfile and update all references.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_bfd) <die_type_hash>: Move to
struct dwarf2_per_objfile.
(struct dwarf2_per_objfile) <die_type_hash>: Move from struct
dwarf2_per_bfd.
* dwarf2/read.c (set_die_type): Update.
(get_die_type_at_offset): Update.
Change-Id: I3589777ed3579bcabafd2ba859d27babe4502bfb
The dwarf2_psymtab and dwarf2_per_cu_quick_data types contain a pointer
to a compunit_symtab, which is a pointer to the corresponding full
symtab. The dwarf2_psymtab and dwarf2_per_cu_quick_data objects are
going to become objfile-independent, and possibly shared by multiple
objfiles, whereas compunit_symtab will stay objfile-dependent. This
backlink to the compunit_symtab must therefore be removed.
This patch replaces them with a vector in the dwarf2_per_objfile type,
that serves as a mapping from dwarf2_per_cu_data objects to
compunit_symtab objects, for this particular objfile. The vector is
indexed using the index assigned to the dwarf2_per_cu_data at its
creation.
I removed the get_compunit_symtab, as it appears to bring not much value
over calling dwarf2_per_objfile::get_symtab directly.
gdb/ChangeLog:
YYYY-MM-DD Tom Tromey <tom@tromey.com>
YYYY-MM-DD Simon Marchi <simon.marchi@efficios.com>
* dwarf2/read.h (struct dwarf2_per_bfd) <num_psymtabs>: New
method.
(struct dwarf2_per_objfile) <resize_symtabs, symtab_set_p,
get_symtab, set_symtab>: New methods.
<m_symtabs>: New field.
(struct dwarf2_psymtab): Derive from partial_symtab.
<readin_p, get_compunit_symtab>: Declare methods.
* dwarf2/read.c (dwarf2_per_objfile::symtab_set_p,
dwarf2_per_objfile::get_symtab, dwarf2_per_objfile::set_symtab):
New methods.
(struct dwarf2_per_cu_quick_data) <compunit_symtab>: Remove.
(dw2_do_instantiate_symtab, dw2_instantiate_symtab)
(dw2_map_expand_apply, dw2_map_symtabs_matching_filename)
(dw2_symtab_iter_next, dw2_print_stats)
(dw2_expand_symtabs_with_fullname)
(dw2_expand_symtabs_matching_one)
(dw_expand_symtabs_matching_file_matcher)
(dw2_find_pc_sect_compunit_symtab, dw2_map_symbol_filenames)
(dw2_debug_names_iterator::next)
(dw2_debug_names_map_matching_symbols)
(fill_in_sig_entry_from_dwo_entry, dwarf2_psymtab::read_symtab)
(process_queue, dwarf2_psymtab::expand_psymtab): Update.
(dwarf2_psymtab::readin_p, dwarf2_psymtab::get_compunit_symtab):
New methods.
(get_compunit_symtab, process_full_comp_unit)
(process_full_type_unit): Update.
(dwarf2_build_psymtabs, dwarf2_initialize_objfile, add_type_unit): Call
Change-Id: Iec53d96e0b70a57d8b68408febdac3c6c3d4854b
This is the first step of splitting dwarf2_per_objfile in two, one
structure for objfile-independent data (dwarf2_per_bfd) and one for
objfile-dependent data (dwarf2_per_objfile).
The existing dwarf2_per_objfile is renamed dwarf2_per_bfd, and a new
dwarf2_per_objfile type is introduced, which sits "in between" the
objfile and dwarf2_per_bfd.
So where we had this before:
objfile -> dwarf2_per_objfile (*)
we now have this:
objfile -> dwarf2_per_objfile -> dwarf2_per_bfd (*)
(*) Note that the dwarf2_per_objfile in the former corresponds to
the dwarf2_per_bfd in the latter.
I've done the minimal amount of changes in this patch: following patches
will incrementally move things that are not actually shareable between
objfiles from dwarf2_per_bfd to dwarf2_per_objfile.
Most references to dwarf2_per_objfile objects are changed to
dwarf2_per_objfile->per_bfd. To avoid many of these replacements, which
would have to be reverted later anyway, I've moved right away the
objfile backlink to the new dwarf2_per_objfile structure in this patch.
I've also moved the read_line_string method, since it references the
objfile backlink, and it's actually not difficult to move.
Once the moves are completed, multiple dwarf2_per_objfile sharing the
same BFD will point to the same single instance of dwarf2_per_bfd (as
long as they don't require relocation).
dwarf2_has_info, where we create these objects, is updated to the new
architecture.
I've had to change the get_gdb_index_contents_ftype typedef and related
functions. The parameter type was changed from dwarf2_per_objfile to
dwarf2_per_bfd, otherwise the template wouldn't work.
Please excuse the terse ChangeLog entry, I have not listed all the
functions where dwarf2_per_objfile has been changed to
dwarf2_per_objfile->per_bfd. It would take a considerable amount of
time and would not really be useful in the end.
gdb/ChangeLog:
* dwarf2/read.h (dwarf2_per_objfile): Rename to dwarf2_per_bfd,
then introduce a new dwarf2_per_objfile type.
<read_line_string>: Move to the new dwarf2_per_objfile type.
<objfile>: Likewise.
(dwarf2_per_bfd): Rename dwarf2_per_objfile to this.
* dwarf2/read.c: Replace references to dwarf2_per_objfile with
dwarf2_per_objfile->per_bfd.
(dwarf2_per_objfile::dwarf2_per_objfile): Rename to...
(dwarf2_per_bfd::dwarf2_per_bfd): ... this.
(dwarf2_per_objfile::free_cached_comp_units): Rename to...
(dwarf2_per_bfd::free_cached_comp_units): ... this.
(dwarf2_has_info): Allocate dwarf2_per_bfd.
(dwarf2_per_objfile::locate_sections): Rename to...
(dwarf2_per_bfd::locate_sections): ... this.
(dwarf2_per_objfile::get_cutu): Rename to...
(dwarf2_per_bfd::get_cutu): ... this.
(dwarf2_per_objfile::get_cu): Rename to...
(dwarf2_per_bfd::get_cu): ... this.
(dwarf2_per_objfile::get_tu): Rename to...
(dwarf2_per_bfd::get_tu): ... this.
(dwarf2_per_objfile::allocate_per_cu): Rename to...
(dwarf2_per_bfd::allocate_per_cu): ... this.
(dwarf2_per_objfile::allocate_signatured_type): Rename to...
(dwarf2_per_bfd::allocate_signatured_type): ... this.
(get_gdb_index_contents_ftype): Change parameter from
dwarf2_per_objfile to dwarf2_per_bfd.
* dwarf2/macro.c, dwarf2/index-write.c: Replace references to
dwarf2_per_objfile with dwarf2_per_objfile->per_bfd.
Change-Id: I7de7b5d1ce7494aa73bfcf15f719d3c5c46e138c
Currently, a dwarf2_per_cu_data can hold a link to the corresponding
expanded compunit_symtab. However, the dwarf2_per_cu_data objects are
shared across objfiles, a simple pointer won't work: each objfile
sharing the dwarf2_per_cu_data instance will have a corresponding
compunit_symtab.
Instead, this link will be stored in the dwarf2_per_objfile object
(which will contain the objfile-specific data). To enable this, we add
an index to each dwarf2_per_cu_data and signatured_type. The data
structure in the dwarf2_per_objfile will use this new index to map a
dwarf2_per_cu_data to its corresponding compunit_symtab, for this
objfile.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_objfile) <allocate_per_cu,
allocate_signatured_type>: Declare new methods.
<m_num_psymtabs>: New member.
(struct dwarf2_per_cu_data) <index>: New member.
* dwarf2/read.c (dwarf2_per_objfile::allocate_per_cu)
(dwarf2_per_objfile::allocate_signatured_type): New methods.
(create_cu_from_index_list): Use allocate_per_cu.
(create_signatured_type_table_from_index)
(create_signatured_type_table_from_debug_names)
(create_debug_type_hash_table, add_type_unit)
(read_comp_units_from_section): Use allocate_signatured_type.
Change-Id: I7733479a38ce82a5015cb184c8acce5f8bbf2e69
Currently much of the DWARF-related data is stored on the objfile
obstack. This prevents sharing this data across objfiles, so this patch
adds a new obstack to dwarf2_per_objfile. Note that the
dwarf2_per_objfile type is going to become "dwarf2_per_bfd" in a
subsequent patch, which is indeed going to be shared between objfiles.
One way to check whether this is correct is to look at the remaining
uses of objfile_obstack in the DWARF code and note that they all
appear in the "full CU" code paths.
The converse -- storing per-objfile data on the shared obstack -- is
not good, but it is just a memory leak, not a potential
use-after-free. Double-checking this would also be useful, though.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_per_objfile) <obstack>: New
member.
* dwarf2/read.c (delete_file_name_entry): Fix comment.
(create_cu_from_index_list)
(create_signatured_type_table_from_index)
(create_signatured_type_table_from_debug_names)
(dw2_get_file_names_reader, dwarf2_initialize_objfile)
(dwarf2_create_include_psymtab)
(create_debug_type_hash_table, add_type_unit)
(create_type_unit_group, read_comp_units_from_section)
(dwarf2_compute_name, create_cus_hash_table)
(create_dwp_hash_table, create_dwo_unit_in_dwp_v1)
(create_dwo_unit_in_dwp_v2, open_and_init_dwp_file): Use new
obstack.
(dw2_get_real_path): Likewise. Change argument to
dwarf2_per_objfile.
Change-Id: Icdec7be7c4d9f33d1dce4f807284f3077f7d3f03
I noticed that only one of the two dwarf2_psymtab constructors are
actually used. The one that is used accepts an `addr` parameter (the
base text offset), but its sole caller passes a constant, 0. We want to
keep calling the three-arguments standard_psymtab constructor form,
however, since it differs from the two-arguments form in subtle ways.
Also, I believe the dwarf2_per_cu_data associated to the created
dwarf2_psymtab should be passed as a constructor argument. That will
help me in a future patchset, to convince myself that the `per_cu_data`
field can't be NULL.
So this patch:
- Removes the two-parameters constructor of dwarf2_psymtab, as it is
unused.
- Removes the `addr` parameter of the remaining constructor, passing 0
directly to the base class' constructor.
- Adds a `per_cu` parameter, to assign the `per_cu_data` field at
construction.
gdb/ChangeLog:
* dwarf2/read.h (struct dwarf2_psymtab): Remove two-parameters
constructor. Remove `addr` parameter from other constructor and
add `per_cu` parameter.
* dwarf2/read.c (create_partial_symtab): Update.
This changes read_indirect_line_string to be a method on
dwarf2_per_objfile. This makes it a bit simpler to share between
files.
gdb/ChangeLog
2020-03-26 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_per_objfile) <read_line_string>:
Declare method.
* dwarf2/read.c (read_attribute_value): Update.
(dwarf2_per_objfile::read_line_string): Rename from
read_indirect_line_string.
(read_formatted_entries): Update.
