+++ /dev/null
-/* DWARF 2 debugging format support for GDB.
-
- Copyright (C) 1994-2020 Free Software Foundation, Inc.
-
- This file is part of GDB.
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
-
-#ifndef DWARF2READ_H
-#define DWARF2READ_H
-
-#include <unordered_map>
-#include "dwarf-index-cache.h"
-#include "dwarf2/section.h"
-#include "filename-seen-cache.h"
-#include "gdb_obstack.h"
-#include "gdbsupport/hash_enum.h"
-#include "psympriv.h"
-
-/* Hold 'maintenance (set|show) dwarf' commands. */
-extern struct cmd_list_element *set_dwarf_cmdlist;
-extern struct cmd_list_element *show_dwarf_cmdlist;
-
-extern bool dwarf_always_disassemble;
-
-struct tu_stats
-{
- int nr_uniq_abbrev_tables;
- int nr_symtabs;
- int nr_symtab_sharers;
- int nr_stmt_less_type_units;
- int nr_all_type_units_reallocs;
-};
-
-struct dwarf2_debug_sections;
-struct mapped_index;
-struct mapped_debug_names;
-struct signatured_type;
-struct die_info;
-typedef struct die_info *die_info_ptr;
-
-/* Collection of data recorded per objfile.
- This hangs off of dwarf2_objfile_data_key. */
-
-struct dwarf2_per_objfile
-{
- /* Construct a dwarf2_per_objfile for OBJFILE. NAMES points to the
- dwarf2 section names, or is NULL if the standard ELF names are
- used. CAN_COPY is true for formats where symbol
- interposition is possible and so symbol values must follow copy
- relocation rules. */
- dwarf2_per_objfile (struct objfile *objfile,
- const dwarf2_debug_sections *names,
- bool can_copy);
-
- ~dwarf2_per_objfile ();
-
- DISABLE_COPY_AND_ASSIGN (dwarf2_per_objfile);
-
- /* Return the CU/TU given its index.
-
- This is intended for loops like:
-
- for (i = 0; i < (dwarf2_per_objfile->n_comp_units
- + dwarf2_per_objfile->n_type_units); ++i)
- {
- dwarf2_per_cu_data *per_cu = dwarf2_per_objfile->get_cutu (i);
-
- ...;
- }
- */
- dwarf2_per_cu_data *get_cutu (int index);
-
- /* Return the CU given its index.
- This differs from get_cutu in that it's for when you know INDEX refers to a
- CU. */
- dwarf2_per_cu_data *get_cu (int index);
-
- /* Return the TU given its index.
- This differs from get_cutu in that it's for when you know INDEX refers to a
- TU. */
- signatured_type *get_tu (int index);
-
- /* Free all cached compilation units. */
- void free_cached_comp_units ();
-private:
- /* This function is mapped across the sections and remembers the
- offset and size of each of the debugging sections we are
- interested in. */
- void locate_sections (bfd *abfd, asection *sectp,
- const dwarf2_debug_sections &names);
-
-public:
- dwarf2_section_info info {};
- dwarf2_section_info abbrev {};
- dwarf2_section_info line {};
- dwarf2_section_info loc {};
- dwarf2_section_info loclists {};
- dwarf2_section_info macinfo {};
- dwarf2_section_info macro {};
- dwarf2_section_info str {};
- dwarf2_section_info str_offsets {};
- dwarf2_section_info line_str {};
- dwarf2_section_info ranges {};
- dwarf2_section_info rnglists {};
- dwarf2_section_info addr {};
- dwarf2_section_info frame {};
- dwarf2_section_info eh_frame {};
- dwarf2_section_info gdb_index {};
- dwarf2_section_info debug_names {};
- dwarf2_section_info debug_aranges {};
-
- std::vector<dwarf2_section_info> types;
-
- /* Back link. */
- struct objfile *objfile = NULL;
-
- /* Table of all the compilation units. This is used to locate
- the target compilation unit of a particular reference. */
- std::vector<dwarf2_per_cu_data *> all_comp_units;
-
- /* The .debug_types-related CUs (TUs). */
- std::vector<signatured_type *> all_type_units;
-
- /* Table of struct type_unit_group objects.
- The hash key is the DW_AT_stmt_list value. */
- htab_t type_unit_groups {};
-
- /* A table mapping .debug_types signatures to its signatured_type entry.
- This is NULL if the .debug_types section hasn't been read in yet. */
- htab_t signatured_types {};
-
- /* Type unit statistics, to see how well the scaling improvements
- are doing. */
- struct tu_stats tu_stats {};
-
- /* A chain of compilation units that are currently read in, so that
- they can be freed later. */
- dwarf2_per_cu_data *read_in_chain = NULL;
-
- /* A table mapping DW_AT_dwo_name values to struct dwo_file objects.
- This is NULL if the table hasn't been allocated yet. */
- htab_up dwo_files;
-
- /* True if we've checked for whether there is a DWP file. */
- bool dwp_checked = false;
-
- /* The DWP file if there is one, or NULL. */
- std::unique_ptr<struct dwp_file> dwp_file;
-
- /* The shared '.dwz' file, if one exists. This is used when the
- original data was compressed using 'dwz -m'. */
- std::unique_ptr<struct dwz_file> dwz_file;
-
- /* Whether copy relocations are supported by this object format. */
- bool can_copy;
-
- /* A flag indicating whether this objfile has a section loaded at a
- VMA of 0. */
- bool has_section_at_zero = false;
-
- /* True if we are using the mapped index,
- or we are faking it for OBJF_READNOW's sake. */
- bool using_index = false;
-
- /* The mapped index, or NULL if .gdb_index is missing or not being used. */
- std::unique_ptr<mapped_index> index_table;
-
- /* The mapped index, or NULL if .debug_names is missing or not being used. */
- std::unique_ptr<mapped_debug_names> debug_names_table;
-
- /* When using index_table, this keeps track of all quick_file_names entries.
- TUs typically share line table entries with a CU, so we maintain a
- separate table of all line table entries to support the sharing.
- Note that while there can be way more TUs than CUs, we've already
- sorted all the TUs into "type unit groups", grouped by their
- DW_AT_stmt_list value. Therefore the only sharing done here is with a
- CU and its associated TU group if there is one. */
- htab_t quick_file_names_table {};
-
- /* Set during partial symbol reading, to prevent queueing of full
- symbols. */
- bool reading_partial_symbols = false;
-
- /* Table mapping type DIEs to their struct type *.
- This is NULL if not allocated yet.
- The mapping is done via (CU/TU + DIE offset) -> type. */
- htab_t die_type_hash {};
-
- /* The CUs we recently read. */
- std::vector<dwarf2_per_cu_data *> just_read_cus;
-
- /* Table containing line_header indexed by offset and offset_in_dwz. */
- htab_t line_header_hash {};
-
- /* Table containing all filenames. This is an optional because the
- table is lazily constructed on first access. */
- gdb::optional<filename_seen_cache> filenames_cache;
-
- /* If we loaded the index from an external file, this contains the
- resources associated to the open file, memory mapping, etc. */
- std::unique_ptr<index_cache_resource> index_cache_res;
-
- /* Mapping from abstract origin DIE to concrete DIEs that reference it as
- DW_AT_abstract_origin. */
- std::unordered_map<sect_offset, std::vector<sect_offset>,
- gdb::hash_enum<sect_offset>>
- abstract_to_concrete;
-};
-
-/* Get the dwarf2_per_objfile associated to OBJFILE. */
-
-dwarf2_per_objfile *get_dwarf2_per_objfile (struct objfile *objfile);
-
-/* A partial symtab specialized for DWARF. */
-struct dwarf2_psymtab : public standard_psymtab
-{
- dwarf2_psymtab (const char *filename, struct objfile *objfile)
- : standard_psymtab (filename, objfile)
- {
- }
-
- dwarf2_psymtab (const char *filename, struct objfile *objfile,
- CORE_ADDR addr)
- : standard_psymtab (filename, objfile, addr)
- {
- }
-
- void read_symtab (struct objfile *) override;
- void expand_psymtab (struct objfile *) override;
-
- struct dwarf2_per_cu_data *per_cu_data;
-};
-
-/* Persistent data held for a compilation unit, even when not
- processing it. We put a pointer to this structure in the
- psymtab. */
-
-struct dwarf2_per_cu_data
-{
- /* The start offset and length of this compilation unit.
- NOTE: Unlike comp_unit_head.length, this length includes
- initial_length_size.
- If the DIE refers to a DWO file, this is always of the original die,
- not the DWO file. */
- sect_offset sect_off;
- unsigned int length;
-
- /* DWARF standard version this data has been read from (such as 4 or 5). */
- short dwarf_version;
-
- /* Flag indicating this compilation unit will be read in before
- any of the current compilation units are processed. */
- unsigned int queued : 1;
-
- /* This flag will be set when reading partial DIEs if we need to load
- absolutely all DIEs for this compilation unit, instead of just the ones
- we think are interesting. It gets set if we look for a DIE in the
- hash table and don't find it. */
- unsigned int load_all_dies : 1;
-
- /* Non-zero if this CU is from .debug_types.
- Struct dwarf2_per_cu_data is contained in struct signatured_type iff
- this is non-zero. */
- unsigned int is_debug_types : 1;
-
- /* Non-zero if this CU is from the .dwz file. */
- unsigned int is_dwz : 1;
-
- /* Non-zero if reading a TU directly from a DWO file, bypassing the stub.
- This flag is only valid if is_debug_types is true.
- We can't read a CU directly from a DWO file: There are required
- attributes in the stub. */
- unsigned int reading_dwo_directly : 1;
-
- /* Non-zero if the TU has been read.
- This is used to assist the "Stay in DWO Optimization" for Fission:
- When reading a DWO, it's faster to read TUs from the DWO instead of
- fetching them from random other DWOs (due to comdat folding).
- If the TU has already been read, the optimization is unnecessary
- (and unwise - we don't want to change where gdb thinks the TU lives
- "midflight").
- This flag is only valid if is_debug_types is true. */
- unsigned int tu_read : 1;
-
- /* The section this CU/TU lives in.
- If the DIE refers to a DWO file, this is always the original die,
- not the DWO file. */
- struct dwarf2_section_info *section;
-
- /* Set to non-NULL iff this CU is currently loaded. When it gets freed out
- of the CU cache it gets reset to NULL again. This is left as NULL for
- dummy CUs (a CU header, but nothing else). */
- struct dwarf2_cu *cu;
-
- /* The corresponding dwarf2_per_objfile. */
- struct dwarf2_per_objfile *dwarf2_per_objfile;
-
- /* When dwarf2_per_objfile->using_index is true, the 'quick' field
- is active. Otherwise, the 'psymtab' field is active. */
- union
- {
- /* The partial symbol table associated with this compilation unit,
- or NULL for unread partial units. */
- dwarf2_psymtab *psymtab;
-
- /* Data needed by the "quick" functions. */
- struct dwarf2_per_cu_quick_data *quick;
- } v;
-
- /* Return true of IMPORTED_SYMTABS is empty or not yet allocated. */
- bool imported_symtabs_empty () const
- {
- return (imported_symtabs == nullptr || imported_symtabs->empty ());
- }
-
- /* Push P to the back of IMPORTED_SYMTABS, allocated IMPORTED_SYMTABS
- first if required. */
- void imported_symtabs_push (dwarf2_per_cu_data *p)
- {
- if (imported_symtabs == nullptr)
- imported_symtabs = new std::vector <dwarf2_per_cu_data *>;
- imported_symtabs->push_back (p);
- }
-
- /* Return the size of IMPORTED_SYMTABS if it is allocated, otherwise
- return 0. */
- size_t imported_symtabs_size () const
- {
- if (imported_symtabs == nullptr)
- return 0;
- return imported_symtabs->size ();
- }
-
- /* Delete IMPORTED_SYMTABS and set the pointer back to nullptr. */
- void imported_symtabs_free ()
- {
- delete imported_symtabs;
- imported_symtabs = nullptr;
- }
-
- /* The CUs we import using DW_TAG_imported_unit. This is filled in
- while reading psymtabs, used to compute the psymtab dependencies,
- and then cleared. Then it is filled in again while reading full
- symbols, and only deleted when the objfile is destroyed.
-
- This is also used to work around a difference between the way gold
- generates .gdb_index version <=7 and the way gdb does. Arguably this
- is a gold bug. For symbols coming from TUs, gold records in the index
- the CU that includes the TU instead of the TU itself. This breaks
- dw2_lookup_symbol: It assumes that if the index says symbol X lives
- in CU/TU Y, then one need only expand Y and a subsequent lookup in Y
- will find X. Alas TUs live in their own symtab, so after expanding CU Y
- we need to look in TU Z to find X. Fortunately, this is akin to
- DW_TAG_imported_unit, so we just use the same mechanism: For
- .gdb_index version <=7 this also records the TUs that the CU referred
- to. Concurrently with this change gdb was modified to emit version 8
- indices so we only pay a price for gold generated indices.
- http://sourceware.org/bugzilla/show_bug.cgi?id=15021.
-
- This currently needs to be a public member due to how
- dwarf2_per_cu_data is allocated and used. Ideally in future things
- could be refactored to make this private. Until then please try to
- avoid direct access to this member, and instead use the helper
- functions above. */
- std::vector <dwarf2_per_cu_data *> *imported_symtabs;
-};
-
-/* Entry in the signatured_types hash table. */
-
-struct signatured_type
-{
- /* The "per_cu" object of this type.
- This struct is used iff per_cu.is_debug_types.
- N.B.: This is the first member so that it's easy to convert pointers
- between them. */
- struct dwarf2_per_cu_data per_cu;
-
- /* The type's signature. */
- ULONGEST signature;
-
- /* Offset in the TU of the type's DIE, as read from the TU header.
- If this TU is a DWO stub and the definition lives in a DWO file
- (specified by DW_AT_GNU_dwo_name), this value is unusable. */
- cu_offset type_offset_in_tu;
-
- /* Offset in the section of the type's DIE.
- If the definition lives in a DWO file, this is the offset in the
- .debug_types.dwo section.
- The value is zero until the actual value is known.
- Zero is otherwise not a valid section offset. */
- sect_offset type_offset_in_section;
-
- /* Type units are grouped by their DW_AT_stmt_list entry so that they
- can share them. This points to the containing symtab. */
- struct type_unit_group *type_unit_group;
-
- /* The type.
- The first time we encounter this type we fully read it in and install it
- in the symbol tables. Subsequent times we only need the type. */
- struct type *type;
-
- /* Containing DWO unit.
- This field is valid iff per_cu.reading_dwo_directly. */
- struct dwo_unit *dwo_unit;
-};
-
-/* This represents a '.dwz' file. */
-
-struct dwz_file
-{
- dwz_file (gdb_bfd_ref_ptr &&bfd)
- : dwz_bfd (std::move (bfd))
- {
- }
-
- const char *filename () const
- {
- return bfd_get_filename (this->dwz_bfd.get ());
- }
-
- /* A dwz file can only contain a few sections. */
- struct dwarf2_section_info abbrev {};
- struct dwarf2_section_info info {};
- struct dwarf2_section_info str {};
- struct dwarf2_section_info line {};
- struct dwarf2_section_info macro {};
- struct dwarf2_section_info gdb_index {};
- struct dwarf2_section_info debug_names {};
-
- /* The dwz's BFD. */
- gdb_bfd_ref_ptr dwz_bfd;
-
- /* If we loaded the index from an external file, this contains the
- resources associated to the open file, memory mapping, etc. */
- std::unique_ptr<index_cache_resource> index_cache_res;
-};
-
-/* Open the separate '.dwz' debug file, if needed. Return NULL if
- there is no .gnu_debugaltlink section in the file. Error if there
- is such a section but the file cannot be found. */
-
-extern struct dwz_file *dwarf2_get_dwz_file
- (struct dwarf2_per_objfile *dwarf2_per_objfile);
-
-#endif /* DWARF2READ_H */
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