/* DWARF 2 debugging format support for GDB.
- Copyright (C) 1994-2020 Free Software Foundation, Inc.
+ Copyright (C) 1994-2021 Free Software Foundation, Inc.
This file is part of GDB.
#include <queue>
#include <unordered_map>
-#include "dwarf2/comp-unit.h"
+#include "dwarf2/comp-unit-head.h"
#include "dwarf2/index-cache.h"
#include "dwarf2/section.h"
#include "filename-seen-cache.h"
int nr_symtab_sharers;
int nr_stmt_less_type_units;
int nr_all_type_units_reallocs;
+ int nr_tus;
};
struct dwarf2_cu;
struct dwarf2_debug_sections;
+struct dwarf2_per_bfd;
struct dwarf2_per_cu_data;
+struct dwarf2_psymtab;
struct mapped_index;
struct mapped_debug_names;
struct signatured_type;
enum language pretend_language;
};
+/* A deleter for dwarf2_per_cu_data that knows to downcast to
+ signatured_type as appropriate. This approach lets us avoid a
+ virtual destructor, which saves a bit of space. */
+
+struct dwarf2_per_cu_data_deleter
+{
+ void operator() (dwarf2_per_cu_data *data);
+};
+
+/* A specialization of unique_ptr for dwarf2_per_cu_data and
+ subclasses. */
+typedef std::unique_ptr<dwarf2_per_cu_data, dwarf2_per_cu_data_deleter>
+ dwarf2_per_cu_data_up;
+
+/* 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
+{
+ dwarf2_per_cu_data ()
+ : queued (false),
+ is_debug_types (false),
+ is_dwz (false),
+ reading_dwo_directly (false),
+ tu_read (false),
+ m_header_read_in (false),
+ unit_type {},
+ lang (language_unknown)
+ {
+ }
+
+ /* 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 = 0;
+
+ /* DWARF standard version this data has been read from (such as 4 or 5). */
+ unsigned char dwarf_version = 0;
+
+ /* Flag indicating this compilation unit will be read in before
+ any of the current compilation units are processed. */
+ unsigned int queued : 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;
+
+ /* True if HEADER has been read in.
+
+ Don't access this field directly. It should be private, but we can't make
+ it private at the moment. */
+ mutable bool m_header_read_in : 1;
+
+ /* The unit type of this CU. */
+ ENUM_BITFIELD (dwarf_unit_type) unit_type : 8;
+
+ /* The language of this CU. */
+ ENUM_BITFIELD (language) lang : LANGUAGE_BITS;
+
+ /* Our index in the unshared "symtabs" vector. */
+ unsigned index = 0;
+
+ /* 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 = nullptr;
+
+ /* Backlink to the owner of this. */
+ dwarf2_per_bfd *per_bfd = nullptr;
+
+ /* DWARF header of this CU. Note that dwarf2_cu reads its own version of the
+ header, which may differ from this one, since it may pass rcuh_kind::TYPE
+ to read_comp_unit_head, whereas for dwarf2_per_cu_data we always pass
+ rcuh_kind::COMPILE.
+
+ Don't access this field directly, use the get_header method instead. It
+ should be private, but we can't make it private at the moment. */
+ mutable comp_unit_head m_header {};
+
+ /* When dwarf2_per_bfd::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 {};
+
+ /* 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 = nullptr;
+
+ /* 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;
+ }
+
+ /* Get the header of this per_cu, reading it if necessary. */
+ const comp_unit_head *get_header () const;
+
+ /* Return the address size given in the compilation unit header for
+ this CU. */
+ int addr_size () const;
+
+ /* Return the offset size given in the compilation unit header for
+ this CU. */
+ int offset_size () const;
+
+ /* Return the DW_FORM_ref_addr size given in the compilation unit
+ header for this CU. */
+ int ref_addr_size () const;
+
+ /* Return DWARF version number of this CU. */
+ short version () const
+ {
+ return dwarf_version;
+ }
+
+ /* A type unit group has a per_cu object that is recognized by
+ having no section. */
+ bool type_unit_group_p () const
+ {
+ return section == nullptr;
+ }
+};
+
+/* Entry in the signatured_types hash table. */
+
+struct signatured_type : public dwarf2_per_cu_data
+{
+ signatured_type (ULONGEST signature)
+ : signature (signature)
+ {}
+
+ /* 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 = nullptr;
+
+ /* Containing DWO unit.
+ This field is valid iff per_cu.reading_dwo_directly. */
+ struct dwo_unit *dwo_unit = nullptr;
+};
+
+using signatured_type_up = std::unique_ptr<signatured_type>;
+
/* Some DWARF data can be shared across objfiles who share the same BFD,
this data is stored in this object.
DISABLE_COPY_AND_ASSIGN (dwarf2_per_bfd);
- /* Return the CU/TU given its index.
-
- This is intended for loops like:
-
- for (i = 0; i < (dwarf2_per_bfd->n_comp_units
- + dwarf2_per_bfd->n_type_units); ++i)
- {
- dwarf2_per_cu_data *per_cu = dwarf2_per_bfd->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);
+ /* Return the CU given its index. */
+ dwarf2_per_cu_data *get_cu (int index) const
+ {
+ return this->all_comp_units[index].get ();
+ }
/* A convenience function to allocate a dwarf2_per_cu_data. The
returned object has its "index" field set properly. The object
is allocated on the dwarf2_per_bfd obstack. */
- dwarf2_per_cu_data *allocate_per_cu ();
+ dwarf2_per_cu_data_up allocate_per_cu ();
/* A convenience function to allocate a signatured_type. The
returned object has its "index" field set properly. The object
is allocated on the dwarf2_per_bfd obstack. */
- signatured_type *allocate_signatured_type ();
-
- /* Return the number of partial symtabs allocated with allocate_per_cu
- and allocate_signatured_type so far. */
- int num_psymtabs () const
- { return m_num_psymtabs; }
+ signatured_type_up allocate_signatured_type (ULONGEST signature);
private:
/* This function is mapped across the sections and remembers the
/* 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;
+ std::vector<dwarf2_per_cu_data_up> all_comp_units;
/* Table of struct type_unit_group objects.
The hash key is the DW_AT_stmt_list value. */
/* The CUs we recently read. */
std::vector<dwarf2_per_cu_data *> just_read_cus;
- /* 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;
abstract_to_concrete;
/* CUs that are queued to be read. */
- std::queue<dwarf2_queue_item> queue;
+ gdb::optional<std::queue<dwarf2_queue_item>> queue;
/* We keep a separate reference to the partial symtabs, in case we
are sharing them between objfiles. This is only set after
partial symbols have been read the first time. */
std::shared_ptr<psymtab_storage> partial_symtabs;
-private:
-
- /* The total number of per_cu and signatured_type objects that have
- been created so far for this reader. */
- size_t m_num_psymtabs = 0;
+ /* The address map that is used by the DWARF index code. */
+ struct addrmap *index_addrmap = nullptr;
};
/* This is the per-objfile data associated with a type_unit_group. */
void resize_symtabs ()
{
/* The symtabs vector should only grow, not shrink. */
- gdb_assert (per_bfd->num_psymtabs () >= m_symtabs.size ());
+ gdb_assert (per_bfd->all_comp_units.size () >= m_symtabs.size ());
- m_symtabs.resize (per_bfd->num_psymtabs ());
+ m_symtabs.resize (per_bfd->all_comp_units.size ());
}
/* Return true if the symtab corresponding to PER_CU has been set,
/* A partial symtab specialized for DWARF. */
struct dwarf2_psymtab : public partial_symtab
{
- dwarf2_psymtab (const char *filename, struct objfile *objfile,
+ dwarf2_psymtab (const char *filename,
+ psymtab_storage *partial_symtabs,
+ objfile_per_bfd_storage *objfile_per_bfd,
dwarf2_per_cu_data *per_cu)
- : partial_symtab (filename, objfile, 0),
+ : partial_symtab (filename, partial_symtabs, objfile_per_bfd, 0),
per_cu_data (per_cu)
{
}
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;
-
- /* Our index in the unshared "symtabs" vector. */
- unsigned index;
-
- /* 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;
-
- /* The unit type of this CU. */
- enum dwarf_unit_type unit_type;
-
- /* The language of this CU. */
- enum language lang;
-
- /* Backlink to the owner of this. */
- dwarf2_per_bfd *per_bfd;
-
- /* DWARF header of this CU. Note that dwarf2_cu reads its own version of the
- header, which may differ from this one, since it may pass rcuh_kind::TYPE
- to read_comp_unit_head, whereas for dwarf2_per_cu_data we always pass
- rcuh_kind::COMPILE.
-
- Don't access this field directly, use the get_header method instead. It
- should be private, but we can't make it private at the moment. */
- mutable comp_unit_head m_header;
-
- /* True if HEADER has been read in.
-
- Don't access this field directly. It should be private, but we can't make
- it private at the moment. */
- mutable bool m_header_read_in;
-
- /* When dwarf2_per_bfd::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;
-
- /* 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;
-
- /* 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;
- }
-
- /* Get the header of this per_cu, reading it if necessary. */
- const comp_unit_head *get_header () const;
-
- /* Return the address size given in the compilation unit header for
- this CU. */
- int addr_size () const;
-
- /* Return the offset size given in the compilation unit header for
- this CU. */
- int offset_size () const;
-
- /* Return the DW_FORM_ref_addr size given in the compilation unit
- header for this CU. */
- int ref_addr_size () const;
-
- /* Return DWARF version number of this CU. */
- short version () const
- {
- return dwarf_version;
- }
-
- /* A type unit group has a per_cu object that is recognized by
- having no section. */
- bool type_unit_group_p () const
- {
- return section == nullptr;
- }
-};
-
-/* 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;
-
- /* Containing DWO unit.
- This field is valid iff per_cu.reading_dwo_directly. */
- struct dwo_unit *dwo_unit;
-};
-
-/* 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 dwz_file *dwarf2_get_dwz_file (dwarf2_per_bfd *per_bfd);
-
/* Return the type of the DIE at DIE_OFFSET in the CU named by
PER_CU. */
/* When non-zero, dump line number entries as they are read in. */
extern unsigned int dwarf_line_debug;
+/* Dwarf2 sections that can be accessed by dwarf2_get_section_info. */
+enum dwarf2_section_enum {
+ DWARF2_DEBUG_FRAME,
+ DWARF2_EH_FRAME
+};
+
+extern void dwarf2_get_section_info (struct objfile *,
+ enum dwarf2_section_enum,
+ asection **, const gdb_byte **,
+ bfd_size_type *);
+
#endif /* DWARF2READ_H */
projects / thirdparty / binutils-gdb.git / blobdiff