[PATCH v2 41/42] Make mapped_debug_names independent of objfile

Simon Marchi
2020-05-12T21:19:12Z

mapped_debug_names currently has a dwarf2_per_objfile field. Since we
want it to become objfile-independent, this field must be removed.

This patch removes it, and then arranges for all methods that needed it
to accept a dwarf2_per_objfile parameter. This trickles down at various
places, like the dw2_debug_names_iterator type.

Ultimately, the objfile only seems to be needed because we might need to
read a string from the string section. For that, we might need to read
in the section, and if it's a relocatable section, the objfile is needed
in order to do the relocation. This pattern happens often (that we to
pass an objfile only because a section might be read). I think it's a
bit ugly, but I don't have a good alternative right now.

gdb/ChangeLog:

* dwarf2/read.c (struct mapped_index_base) <symbol_name_at,
build_name_components, find_name_components_bounds>:
Add per_objfile parameter.
(struct mapped_index) <symbol_name_at>: Likewise.
(struct mapped_debug_names): Remove constructor.
<dwarf2_per_objfile>: Remove field.
<namei_to_name, symbol_name_at>: Add per_objfile parameter.
(mapped_index_base::find_name_components_bounds,
mapped_index_base::build_name_components,
dw2_expand_symtabs_matching_symbol): Likewise.
(class mock_mapped_index) <symbol_name_at>: Likewise.
(check_match): Likewise.
(check_find_bounds_finds): Likewise.
(test_mapped_index_find_name_component_bounds): Update.
(CHECK_MATCH): Update.
(dw2_expand_symtabs_matching): Update.
(class dw2_debug_names_iterator) <dw2_debug_names_iterator>: Add
per_objfile parameter.
<find_vec_in_debug_names>: Likewise.
<m_per_objfile>: New field.
(mapped_debug_names::namei_to_name): Add dwarf2_per_objfile
parameter.
(dw2_debug_names_iterator::find_vec_in_debug_names): Likewise.
(dw2_debug_names_iterator::next): Update.
(dw2_debug_names_lookup_symbol): Update.
(dw2_debug_names_expand_symtabs_for_function): Update.
(dw2_debug_names_map_matching_symbols): Update.
(dw2_debug_names_expand_symtabs_matching): Update.
(dwarf2_read_debug_names): Update.
---
gdb/dwarf2/read.c | 163 ++++++++++++++++++++++++++--------------------
1 file changed, 91 insertions(+), 72 deletions(-)

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 9bc19a089b0..3f93a51381f 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -164,7 +164,8 @@ struct mapped_index_base
virtual size_t symbol_name_count () const = 0;

/* Get the name of the symbol at IDX in the symbol table. */
- virtual const char *symbol_name_at (offset_type idx) const = 0;
+ virtual const char *symbol_name_at
+ (offset_type idx, dwarf2_per_objfile *per_objfile) const = 0;

/* Return whether the name at IDX in the symbol table should be
ignored. */
@@ -175,7 +176,7 @@ struct mapped_index_base

/* Build the symbol name component sorted vector, if we haven't
yet. */
- void build_name_components ();
+ void build_name_components (dwarf2_per_objfile *per_objfile);

/* Returns the lower (inclusive) and upper (exclusive) bounds of the
possible matches for LN_NO_PARAMS in the name component
@@ -183,7 +184,8 @@ struct mapped_index_base
std::pair<std::vector<name_component>::const_iterator,
std::vector<name_component>::const_iterator>
find_name_components_bounds (const lookup_name_info &ln_no_params,
- enum language lang) const;
+ enum language lang,
+ dwarf2_per_objfile *per_objfile) const;

/* Prevent deleting/destroying via a base class pointer. */
protected:
@@ -221,7 +223,8 @@ struct mapped_index final : public mapped_index_base

/* Convenience method to get at the name of the symbol at IDX in the
symbol table. */
- const char *symbol_name_at (offset_type idx) const override
+ const char *symbol_name_at
+ (offset_type idx, dwarf2_per_objfile *per_objfile) const override
{ return this->constant_pool + MAYBE_SWAP (this->symbol_table[idx].name); }

size_t symbol_name_count () const override
@@ -232,11 +235,6 @@ struct mapped_index final : public mapped_index_base
Uninitialized map has CU_COUNT 0. */
struct mapped_debug_names final : public mapped_index_base
{
- mapped_debug_names (struct dwarf2_per_objfile *dwarf2_per_objfile_)
- : dwarf2_per_objfile (dwarf2_per_objfile_)
- {}
-
- struct dwarf2_per_objfile *dwarf2_per_objfile;
bfd_endian dwarf5_byte_order;
bool dwarf5_is_dwarf64;
bool augmentation_is_gdb;
@@ -268,13 +266,15 @@ struct mapped_debug_names final : public mapped_index_base

std::unordered_map<ULONGEST, index_val> abbrev_map;

- const char *namei_to_name (uint32_t namei) const;
+ const char *namei_to_name
+ (uint32_t namei, dwarf2_per_objfile *per_objfile) const;

/* Implementation of the mapped_index_base virtual interface, for
the name_components cache. */

- const char *symbol_name_at (offset_type idx) const override
- { return namei_to_name (idx); }
+ const char *symbol_name_at
+ (offset_type idx, dwarf2_per_objfile *per_objfile) const override
+ { return namei_to_name (idx, per_objfile); }

size_t symbol_name_count () const override
{ return this->name_count; }
@@ -3802,7 +3802,8 @@ make_sort_after_prefix_name (const char *search_name)
std::pair<std::vector<name_component>::const_iterator,
std::vector<name_component>::const_iterator>
mapped_index_base::find_name_components_bounds
- (const lookup_name_info &lookup_name_without_params, language lang) const
+ (const lookup_name_info &lookup_name_without_params, language lang,
+ dwarf2_per_objfile *per_objfile) const
{
auto *name_cmp
= this->name_components_casing == case_sensitive_on ? strcmp : strcasecmp;
@@ -3815,7 +3816,7 @@ mapped_index_base::find_name_components_bounds
auto lookup_compare_lower = [&] (const name_component &elem,
const char *name)
{
- const char *elem_qualified = this->symbol_name_at (elem.idx);
+ const char *elem_qualified = this->symbol_name_at (elem.idx, per_objfile);
const char *elem_name = elem_qualified + elem.name_offset;
return name_cmp (elem_name, name) < 0;
};
@@ -3825,7 +3826,7 @@ mapped_index_base::find_name_components_bounds
auto lookup_compare_upper = [&] (const char *name,
const name_component &elem)
{
- const char *elem_qualified = this->symbol_name_at (elem.idx);
+ const char *elem_qualified = this->symbol_name_at (elem.idx, per_objfile);
const char *elem_name = elem_qualified + elem.name_offset;
return name_cmp (name, elem_name) < 0;
};
@@ -3874,7 +3875,7 @@ mapped_index_base::find_name_components_bounds
/* See declaration. */

void
-mapped_index_base::build_name_components ()
+mapped_index_base::build_name_components (dwarf2_per_objfile *per_objfile)
{
if (!this->name_components.empty ())
return;
@@ -3892,7 +3893,7 @@ mapped_index_base::build_name_components ()
if (this->symbol_name_slot_invalid (idx))
continue;

- const char *name = this->symbol_name_at (idx);
+ const char *name = this->symbol_name_at (idx, per_objfile);

/* Add each name component to the name component table. */
unsigned int previous_len = 0;
@@ -3930,8 +3931,10 @@ mapped_index_base::build_name_components ()
auto name_comp_compare = [&] (const name_component &left,
const name_component &right)
{
- const char *left_qualified = this->symbol_name_at (left.idx);
- const char *right_qualified = this->symbol_name_at (right.idx);
+ const char *left_qualified
+ = this->symbol_name_at (left.idx, per_objfile);
+ const char *right_qualified
+ = this->symbol_name_at (right.idx, per_objfile);

const char *left_name = left_qualified + left.name_offset;
const char *right_name = right_qualified + right.name_offset;
@@ -3957,14 +3960,15 @@ dw2_expand_symtabs_matching_symbol
const lookup_name_info &lookup_name_in,
gdb::function_view<expand_symtabs_symbol_matcher_ftype> symbol_matcher,
enum search_domain kind,
- gdb::function_view<bool (offset_type)> match_callback)
+ gdb::function_view<bool (offset_type)> match_callback,
+ dwarf2_per_objfile *per_objfile)
{
lookup_name_info lookup_name_without_params
= lookup_name_in.make_ignore_params ();

/* Build the symbol name component sorted vector, if we haven't
yet. */
- index.build_name_components ();
+ index.build_name_components (per_objfile);

/* The same symbol may appear more than once in the range though.
E.g., if we're looking for symbols that complete "w", and we have
@@ -4014,14 +4018,15 @@ dw2_expand_symtabs_matching_symbol

auto bounds
= index.find_name_components_bounds (lookup_name_without_params,
- lang_e);
+ lang_e, per_objfile);

/* Now for each symbol name in range, check to see if we have a name
match, and if so, call the MATCH_CALLBACK callback. */

for (; bounds.first != bounds.second; ++bounds.first)
{
- const char *qualified = index.symbol_name_at (bounds.first->idx);
+ const char *qualified
+ = index.symbol_name_at (bounds.first->idx, per_objfile);

if (!name_matcher (qualified, lookup_name_without_params, NULL)
|| (symbol_matcher != NULL && !symbol_matcher (qualified)))
@@ -4074,7 +4079,8 @@ class mock_mapped_index : public mapped_index_base
}

/* Get the name of the symbol at IDX in the symbol table. */
- const char *symbol_name_at (offset_type idx) const override
+ const char *symbol_name_at
+ (offset_type idx, dwarf2_per_objfile *per_objfile) const override
{
return m_symbol_table[idx];
}
@@ -4104,7 +4110,8 @@ check_match (const char *file, int line,
mock_mapped_index &mock_index,
const char *name, symbol_name_match_type match_type,
bool completion_mode,
- std::initializer_list<const char *> expected_list)
+ std::initializer_list<const char *> expected_list,
+ dwarf2_per_objfile *per_objfile)
{
lookup_name_info lookup_name (name, match_type, completion_mode);

@@ -4129,14 +4136,14 @@ check_match (const char *file, int line,
NULL, ALL_DOMAIN,
[&] (offset_type idx)
{
- const char *matched_name = mock_index.symbol_name_at (idx);
+ const char *matched_name = mock_index.symbol_name_at (idx, per_objfile);
const char *expected_str
= expected_it == expected_end ? NULL : *expected_it++;

if (expected_str == NULL || strcmp (expected_str, matched_name) != 0)
mismatch (expected_str, matched_name);
return true;
- });
+ }, per_objfile);

const char *expected_str
= expected_it == expected_end ? NULL : *expected_it++;
@@ -4197,13 +4204,15 @@ static const char *test_symbols[] = {
static bool
check_find_bounds_finds (mapped_index_base &index,
const char *search_name,
- gdb::array_view<const char *> expected_syms)
+ gdb::array_view<const char *> expected_syms,
+ dwarf2_per_objfile *per_objfile)
{
lookup_name_info lookup_name (search_name,
symbol_name_match_type::FULL, true);

auto bounds = index.find_name_components_bounds (lookup_name,
- language_cplus);
+ language_cplus,
+ per_objfile);

size_t distance = std::distance (bounds.first, bounds.second);
if (distance != expected_syms.size ())
@@ -4212,7 +4221,7 @@ check_find_bounds_finds (mapped_index_base &index,
for (size_t exp_elem = 0; exp_elem < distance; exp_elem++)
{
auto nc_elem = bounds.first + exp_elem;
- const char *qualified = index.symbol_name_at (nc_elem->idx);
+ const char *qualified = index.symbol_name_at (nc_elem->idx, per_objfile);
if (strcmp (qualified, expected_syms[exp_elem]) != 0)
return false;
}
@@ -4228,7 +4237,7 @@ test_mapped_index_find_name_component_bounds ()
{
mock_mapped_index mock_index (test_symbols);

- mock_index.build_name_components ();
+ mock_index.build_name_components (NULL /* per_objfile */);

/* Test the lower-level mapped_index::find_name_component_bounds
method in completion mode. */
@@ -4238,8 +4247,9 @@ test_mapped_index_find_name_component_bounds ()
"t1_func1",
};

- SELF_CHECK (check_find_bounds_finds (mock_index,
- "t1_func", expected_syms));
+ SELF_CHECK (check_find_bounds_finds
+ (mock_index, "t1_func", expected_syms,
+ NULL /* per_objfile */));
}

/* Check that the increment-last-char in the name matching algorithm
@@ -4249,14 +4259,15 @@ test_mapped_index_find_name_component_bounds ()
"\377",
"\377\377123",
};
- SELF_CHECK (check_find_bounds_finds (mock_index,
- "\377", expected_syms1));
+ SELF_CHECK (check_find_bounds_finds
+ (mock_index, "\377", expected_syms1, NULL /* per_objfile */));

static const char *expected_syms2[] = {
"\377\377123",
};
- SELF_CHECK (check_find_bounds_finds (mock_index,
- "\377\377", expected_syms2));
+ SELF_CHECK (check_find_bounds_finds
+ (mock_index, "\377\377", expected_syms2,
+ NULL /* per_objfile */));
}
}

@@ -4282,7 +4293,7 @@ test_dw2_expand_symtabs_matching_symbol ()
any_mismatch |= !check_match (__FILE__, __LINE__, \
mock_index, \
NAME, MATCH_TYPE, COMPLETION_MODE, \
- EXPECTED_LIST)
+ EXPECTED_LIST, NULL)

/* Identity checks. */
for (const char *sym : test_symbols)
@@ -4705,7 +4716,7 @@ dw2_expand_symtabs_matching
dw2_expand_marked_cus (dwarf2_per_objfile, idx, file_matcher,
expansion_notify, kind);
return true;
- });
+ }, dwarf2_per_objfile);
}

/* A helper for dw2_find_pc_sect_compunit_symtab which finds the most specific
@@ -5132,9 +5143,8 @@ create_cus_from_debug_names (dwarf2_per_bfd *per_bfd,
static bool
dwarf2_read_debug_names (struct dwarf2_per_objfile *dwarf2_per_objfile)
{
- std::unique_ptr<mapped_debug_names> map
- (new mapped_debug_names (dwarf2_per_objfile));
- mapped_debug_names dwz_map (dwarf2_per_objfile);
+ std::unique_ptr<mapped_debug_names> map (new mapped_debug_names);
+ mapped_debug_names dwz_map;
struct objfile *objfile = dwarf2_per_objfile->objfile;

if (!read_debug_names_from_section (objfile, objfile_name (objfile),
@@ -5196,23 +5206,26 @@ class dw2_debug_names_iterator
dw2_debug_names_iterator (const mapped_debug_names &map,
gdb::optional<block_enum> block_index,
domain_enum domain,
- const char *name)
+ const char *name, dwarf2_per_objfile *per_objfile)
: m_map (map), m_block_index (block_index), m_domain (domain),
- m_addr (find_vec_in_debug_names (map, name))
+ m_addr (find_vec_in_debug_names (map, name, per_objfile)),
+ m_per_objfile (per_objfile)
{}

dw2_debug_names_iterator (const mapped_debug_names &map,
- search_domain search, uint32_t namei)
+ search_domain search, uint32_t namei, dwarf2_per_objfile *per_objfile)
: m_map (map),
m_search (search),
- m_addr (find_vec_in_debug_names (map, namei))
+ m_addr (find_vec_in_debug_names (map, namei, per_objfile)),
+ m_per_objfile (per_objfile)
{}

dw2_debug_names_iterator (const mapped_debug_names &map,
block_enum block_index, domain_enum domain,
- uint32_t namei)
+ uint32_t namei, dwarf2_per_objfile *per_objfile)
: m_map (map), m_block_index (block_index), m_domain (domain),
- m_addr (find_vec_in_debug_names (map, namei))
+ m_addr (find_vec_in_debug_names (map, namei, per_objfile)),
+ m_per_objfile (per_objfile)
{}

/* Return the next matching CU or NULL if there are no more. */
@@ -5220,9 +5233,9 @@ class dw2_debug_names_iterator

private:
static const gdb_byte *find_vec_in_debug_names (const mapped_debug_names &map,
- const char *name);
+ const char *name, dwarf2_per_objfile *per_objfile);
static const gdb_byte *find_vec_in_debug_names (const mapped_debug_names &map,
- uint32_t namei);
+ uint32_t namei, dwarf2_per_objfile *per_objfile);

/* The internalized form of .debug_names. */
const mapped_debug_names &m_map;
@@ -5238,10 +5251,13 @@ class dw2_debug_names_iterator
/* The list of CUs from the index entry of the symbol, or NULL if
not found. */
const gdb_byte *m_addr;
+
+ dwarf2_per_objfile *m_per_objfile;
};

const char *
-mapped_debug_names::namei_to_name (uint32_t namei) const
+mapped_debug_names::namei_to_name
+ (uint32_t namei, dwarf2_per_objfile *dwarf2_per_objfile) const
{
const ULONGEST namei_string_offs
= extract_unsigned_integer ((name_table_string_offs_reordered
@@ -5258,7 +5274,7 @@ mapped_debug_names::namei_to_name (uint32_t namei) const

const gdb_byte *
dw2_debug_names_iterator::find_vec_in_debug_names
- (const mapped_debug_names &map, const char *name)
+ (const mapped_debug_names &map, const char *name, dwarf2_per_objfile *per_objfile)
{
int (*cmp) (const char *, const char *);

@@ -5294,7 +5310,7 @@ dw2_debug_names_iterator::find_vec_in_debug_names
complaint (_("Wrong .debug_names with name index %u but name_count=%u "
"[in module %s]"),
namei, map.name_count,
- objfile_name (map.dwarf2_per_objfile->objfile));
+ objfile_name (per_objfile->objfile));
return NULL;
}

@@ -5309,7 +5325,7 @@ dw2_debug_names_iterator::find_vec_in_debug_names

if (full_hash == namei_full_hash)
{
- const char *const namei_string = map.namei_to_name (namei);
+ const char *const namei_string = map.namei_to_name (namei, per_objfile);

#if 0 /* An expensive sanity check. */
if (namei_full_hash != dwarf5_djb_hash (namei_string))
@@ -5339,14 +5355,14 @@ dw2_debug_names_iterator::find_vec_in_debug_names

const gdb_byte *
dw2_debug_names_iterator::find_vec_in_debug_names
- (const mapped_debug_names &map, uint32_t namei)
+ (const mapped_debug_names &map, uint32_t namei, dwarf2_per_objfile *per_objfile)
{
if (namei >= map.name_count)
{
complaint (_("Wrong .debug_names with name index %u but name_count=%u "
"[in module %s]"),
namei, map.name_count,
- objfile_name (map.dwarf2_per_objfile->objfile));
+ objfile_name (per_objfile->objfile));
return NULL;
}

@@ -5365,8 +5381,8 @@ dw2_debug_names_iterator::next ()
if (m_addr == NULL)
return NULL;

- struct dwarf2_per_objfile *dwarf2_per_objfile = m_map.dwarf2_per_objfile;
- struct objfile *objfile = dwarf2_per_objfile->objfile;
+ dwarf2_per_bfd *per_bfd = m_per_objfile->per_bfd;
+ struct objfile *objfile = m_per_objfile->objfile;
bfd *const abfd = objfile->obfd;

again:
@@ -5429,33 +5445,33 @@ dw2_debug_names_iterator::next ()
{
case DW_IDX_compile_unit:
/* Don't crash on bad data. */
- if (ull >= dwarf2_per_objfile->per_bfd->all_comp_units.size ())
+ if (ull >= m_per_objfile->per_bfd->all_comp_units.size ())
{
complaint (_(".debug_names entry has bad CU index %s"
" [in module %s]"),
pulongest (ull),
- objfile_name (dwarf2_per_objfile->objfile));
+ objfile_name (objfile));
continue;
}
- per_cu = dwarf2_per_objfile->per_bfd->get_cutu (ull);
+ per_cu = per_bfd->get_cutu (ull);
break;
case DW_IDX_type_unit:
/* Don't crash on bad data. */
- if (ull >= dwarf2_per_objfile->per_bfd->all_type_units.size ())
+ if (ull >= per_bfd->all_type_units.size ())
{
complaint (_(".debug_names entry has bad TU index %s"
" [in module %s]"),
pulongest (ull),
- objfile_name (dwarf2_per_objfile->objfile));
+ objfile_name (objfile));
continue;
}
- per_cu = &dwarf2_per_objfile->per_bfd->get_tu (ull)->per_cu;
+ per_cu = &per_bfd->get_tu (ull)->per_cu;
break;
case DW_IDX_die_offset:
/* In a per-CU index (as opposed to a per-module index), index
entries without CU attribute implicitly refer to the single CU. */
if (per_cu == NULL)
- per_cu = dwarf2_per_objfile->per_bfd->get_cu (0);
+ per_cu = per_bfd->get_cu (0);
break;
case DW_IDX_GNU_internal:
if (!m_map.augmentation_is_gdb)
@@ -5471,7 +5487,7 @@ dw2_debug_names_iterator::next ()
}

/* Skip if already read in. */
- if (dwarf2_per_objfile->symtab_set_p (per_cu))
+ if (m_per_objfile->symtab_set_p (per_cu))
goto again;

/* Check static vs global. */
@@ -5596,7 +5612,8 @@ dw2_debug_names_lookup_symbol (struct objfile *objfile, block_enum block_index,
}
const auto &map = *mapp;

- dw2_debug_names_iterator iter (map, block_index, domain, name);
+ dw2_debug_names_iterator iter (map, block_index, domain, name,
+ dwarf2_per_objfile);

struct compunit_symtab *stab_best = NULL;
struct dwarf2_per_cu_data *per_cu;
@@ -5660,7 +5677,8 @@ dw2_debug_names_expand_symtabs_for_function (struct objfile *objfile,
{
const mapped_debug_names &map = *dwarf2_per_objfile->per_bfd->debug_names_table;

- dw2_debug_names_iterator iter (map, {}, VAR_DOMAIN, func_name);
+ dw2_debug_names_iterator iter (map, {}, VAR_DOMAIN, func_name,
+ dwarf2_per_objfile);

struct dwarf2_per_cu_data *per_cu;
while ((per_cu = iter.next ()) != NULL)
@@ -5699,14 +5717,15 @@ dw2_debug_names_map_matching_symbols
{
/* The name was matched, now expand corresponding CUs that were
marked. */
- dw2_debug_names_iterator iter (map, block_kind, domain, namei);
+ dw2_debug_names_iterator iter (map, block_kind, domain, namei,
+ dwarf2_per_objfile);

struct dwarf2_per_cu_data *per_cu;
while ((per_cu = iter.next ()) != NULL)
dw2_expand_symtabs_matching_one (per_cu, dwarf2_per_objfile, nullptr,
nullptr);
return true;
- });
+ }, dwarf2_per_objfile);

/* It's a shame we couldn't do this inside the
dw2_expand_symtabs_matching_symbol callback, but that skips CUs
@@ -5764,14 +5783,14 @@ dw2_debug_names_expand_symtabs_matching
{
/* The name was matched, now expand corresponding CUs that were
marked. */
- dw2_debug_names_iterator iter (map, kind, namei);
+ dw2_debug_names_iterator iter (map, kind, namei, dwarf2_per_objfile);

struct dwarf2_per_cu_data *per_cu;
while ((per_cu = iter.next ()) != NULL)
dw2_expand_symtabs_matching_one (per_cu, dwarf2_per_objfile,
file_matcher, expansion_notify);
return true;
- });
+ }, dwarf2_per_objfile);
}

const struct quick_symbol_functions dwarf2_debug_names_functions =
--
2.26.2