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.
The DWARF standard appendix E.1 describes techniques that can be used for
compression and deduplication: DIEs can be factored out into a new compilation
unit, and referenced using DW_FORM_ref_addr.
Such a new compilation unit can either use a DW_TAG_compile_unit or
DW_TAG_partial_unit. If a DW_TAG_compile_unit is used, its contents is
evaluated by consumers as though it were an ordinary compilation unit. If a
DW_TAG_partial_unit is used, it's only considered by consumers in the context
of a DW_TAG_imported_unit.
An example of when DW_TAG_partial_unit is required is when the factored out
DIEs are not top-level, f.i. because they were children of a namespace. In
such a case the corresponding DW_TAG_imported_unit will occur as child of the
namespace.
In the case of factoring out DIEs from c++ compilation units, we can factor
out into a new DW_TAG_compile_unit, and no DW_TAG_imported_unit is required.
This begs the question how to interpret a top-level DW_TAG_imported_unit of a
c++ DW_TAG_compile_unit compilation unit. The semantics of
DW_TAG_imported_unit describe that the imported unit logically appears at the
point of the DW_TAG_imported_unit entry. But it's not clear what the effect
should be in this case, since all the imported DIEs are already globally
visible anyway, due to the use of DW_TAG_compile_unit.
So, skip top-level imports of c++ DW_TAG_compile_unit compilation units in
process_imported_unit_die.
Using the cc1 binary from PR23710 comment 1 and setting a breakpoint on do_rpo_vn:
...
$ gdb \
-batch \
-iex "maint set dwarf max-cache-age 316" \
-iex "set language c++" \
-ex "b do_rpo_vn" \
cc1
...
we get a 8.1% reduction in execution time, due to reducing the number of
partial symtabs expanded into full symtabs from 212 to 175.
Build and reg-tested on x86_64-linux.
gdb/ChangeLog:
2020-03-17 Tom de Vries <tdevries@suse.de>
PR gdb/23710
* dwarf2/read.h (struct dwarf2_per_cu_data): Add unit_type and lang
fields.
* dwarf2/read.c (process_psymtab_comp_unit): Initialize unit_type and lang
fields.
(process_imported_unit_die): Skip import of c++ CUs.
All these functions have their implementations in dwarf2/read.c, so move
their declarations to dwarf2/read.h. Move the doc to the header, at the
same time.
gdb/ChangeLog:
* dwarf2/loc.h (dwarf2_fetch_die_loc_sect_off,
dwarf2_fetch_die_loc_cu_off, dwarf2_fetch_constant_bytes,
dwarf2_fetch_die_type_sect_off): Move to...
* dwarf2/read.h (dwarf2_fetch_die_loc_sect_off,
dwarf2_fetch_die_loc_cu_off, dwarf2_fetch_constant_bytes,
dwarf2_fetch_die_type_sect_off): ... here.
* dwarf2/read.c (dwarf2_fetch_die_loc_sect_off,
dwarf2_fetch_die_loc_cu_off, dwarf2_fetch_constant_bytes,
dwarf2_fetch_die_type_sect_off): Move doc to header file.
The implementation is in dwarf2/read.c, so the declaration belongs in
dwarf2/read.h. Also, move the documentation there.
gdb/ChangeLog:
* dwarf2/loc.h (dwarf2_read_addr_index): Move...
* dwarf2/read.h (dwarf2_read_addr_index): ... here.
* dwarf2/read.c (dwarf2_read_addr_index): Move doc to header.
Since its implementation is in dwarf2/read.c, its declaration belongs in
dwarf2/read.h. Move the documentation to the .h at the same time.
gdb/ChangeLog:
* loc.h (dwarf2_get_die_type): Move to...
* read.h (dwarf2_get_die_type): ... here.
* read.c (dwarf2_get_die_type): Move doc to header.
This converts the IS_TYPE_UNIT_GROUP to a method on
dwarf2_per_cu_data.
gdb/ChangeLog
2020-02-24 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_per_cu_data) <type_unit_group_p>:
New method.
* dwarf2/read.c (IS_TYPE_UNIT_GROUP): Remove.
(dw2_do_instantiate_symtab, dw2_get_file_names)
(build_type_psymtab_dependencies, load_full_type_unit): Update.
This moves dwarf2_per_cu_data::imported_symtabs earlier, near where
the other data members are located.
2020-02-08 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_per_cu_data) <imported_symtabs>:
Move earlier.
Change-Id: I314ddaa6f67c53a848e513b3f6d42913bd957833
This moves the line_header class to a pair of new files, making
dwarf2/read.c somewhat smaller.
2020-02-08 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (dwarf_line_debug): Declare.
* Makefile.in (COMMON_SFILES): Add dwarf2/line-header.c.
* dwarf2/read.c: Move line_header code to new files.
(dwarf_line_debug): No longer static.
* dwarf2/line-header.c: New file.
* dwarf2/line-header.h: New file.
Change-Id: I8d9d8a2398b4e888e20cc5dd68d041c28b5a06e3
dwarf_always_disassemble is only used in dwarf2/loc.c, so move the
definition and the command infrastructure to that file.
2020-02-08 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (dwarf_always_disassemble)
(show_dwarf_always_disassemble): Move to loc.c.
(_initialize_dwarf2_read): Move "always-disassemble" registration
to loc.c.
* dwarf2/read.h (dwarf_always_disassemble): Don't declare.
* dwarf2/loc.c (dwarf_always_disassemble): Move from read.c. Now
static.
(show_dwarf_always_disassemble): Move from read.c.
(_initialize_dwarf2loc): Move always-disassemble from read.c.
Change-Id: I33fb88112e98e583c3f4919d20e4d100f2ea0124
This changes dwarf2_per_objfile::quick_file_names_table to be an
htab_up. This just removes a bit of manual management.
2020-02-08 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (~dwarf2_per_objfile): Update.
(create_quick_file_names_table): Return htab_up.
(dw2_get_file_names_reader, dw2_forget_cached_source_info):
Update.
* dwarf2/read.h (struct dwarf2_per_objfile)
<quick_file_names_table>: Now htab_up.
Change-Id: I4ff2fce8b8af27f4bfe01a11b97a889edfd23151
This changes dwarf2_per_objfile::die_type_hash to be an htab_up,
moving its contents off the objfile obstack.
2020-02-08 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (set_die_type, get_die_type_at_offset): Update.
* dwarf2/read.h (struct dwarf2_per_objfile) <die_type_hash>: Now
htab_up.
Change-Id: Ic651f99ebf71bf7ad2dc2880192adacf7b60964a
This changes dwarf2_per_objfile::line_header_hash to be an htab_up,
and changes it to use heap allocation.
2020-02-08 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (~dwarf2_per_objfile): Don't delete
line_header_hash.
(handle_DW_AT_stmt_list): Update. Don't allocate on obstack.
* dwarf2/read.h (struct dwarf2_per_objfile) <line_header_hash>:
Change type to htab_up.
Change-Id: Icb148a270838c0f96f38fc4a28b5b77d067927b6
This changes dwarf2_per_objfile::type_unit_groups to be an htab_up,
again allowing us to move the memory used by the hash table from the
objfile obstack to the heap.
2020-02-08 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (allocate_type_unit_groups_table): Return
htab_up. Don't allocate on obstack.
(get_type_unit_group, dwarf2_build_psymtabs_hard): Update.
* dwarf2/read.h (struct dwarf2_per_objfile) <type_unit_groups>:
Change type to htab_up.
Change-Id: Ia045df0ff3ec30aac813da5a9a2314a607ef7ec8
This changes dwarf2_per_objfile::signatured_types to be an htab_up.
This in turn lets us change it not to use the objfile obstack for
allocation; obstack allocation for hash tables is a bad practice
because it leads to excess memory use if the table is ever resized.
gdb/ChangeLog
2020-02-08 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_per_objfile) <signatured_types>:
Change type to htab_up.
* dwarf2/read.c (create_signatured_type_table_from_index)
(create_signatured_type_table_from_debug_names)
(create_all_type_units, add_type_unit)
(lookup_dwo_signatured_type, lookup_signatured_type)
(process_skeletonless_type_unit): Update.
(create_debug_type_hash_table, create_debug_types_hash_table):
Change type of types_htab.
(allocate_signatured_type_table, allocate_dwo_unit_table): Return
htab_up. Don't allocate on obstack.
(create_cus_hash_table): Change type of cus_htab parameter.
(struct dwo_file) <cus, tus>: Now htab_up.
(lookup_dwo_signatured_type, lookup_dwo_cutu)
(process_dwo_file_for_skeletonless_type_units, lookup_dwo_cutu)
(queue_and_load_all_dwo_tus): Update.
* dwarf2/index-write.c (write_gdbindex): Update.
(write_debug_names): Update.
Change-Id: I290a209b96945fb5f415c82723b62830e9c4b467
This removes some queue-related globals from the DWARF reader, in
favor of a new member on dwarf2_per_objfile. Globals must be avoided
in this code, because they prevent multi-threading the reader.
gdb/ChangeLog
2020-02-08 Tom Tromey <tom@tromey.com>
* dwarf2/read.h (struct dwarf2_queue_item): Move from
dwarf2/read.c. Remove "next" member. Add constructor ntad
destructor.
(struct dwarf2_per_objfile) <queue>: New member.
* dwarf2/read.c (struct dwarf2_queue_item): Move to
dwarf2/read.h.
(dwarf2_queue, dwarf2_queue_tail): Remove.
(class dwarf2_queue_guard): Add parameter to constructor. Use
DISABLE_COPY_AND_ASSIGN.
<m_per_objfile>: New member.
<~dwarf2_queue_guard>: Rewrite.
(dw2_do_instantiate_symtab, queue_comp_unit, process_queue):
Update.
(~dwarf2_queue_item): New.
Change-Id: Ied1f6ff3691352a66c4709b0b2cba0588f49f79a
