aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSimon Marchi <simon.marchi@efficios.com>2024-08-22 14:01:58 -0400
committerSimon Marchi <simon.marchi@efficios.com>2024-08-23 14:41:49 -0400
commitee8f65ec48cfadf10f2fb2191592bebd37dedd8a (patch)
tree4f49623ba66a8114c7b9f20a10d5b8586ace3ee6
parent18784a7fe2bdbcbc5b03fe675ecbfe1e71085497 (diff)
downloadgdb-users/simark/try-cxx-hash-table.zip
gdb-users/simark/try-cxx-hash-table.tar.gz
gdb-users/simark/try-cxx-hash-table.tar.bz2
Convert dwarf2_per_objfile::die_type_hash to new hash tableusers/simark/try-cxx-hash-table
Convert dwarf2_per_objfile::die_type_hash, which maps debug info offsets to `type *`, to gdb::unordered_map. Change-Id: I5c174af64ee46d38a465008090e812acf03704ec
-rw-r--r--gdb/dwarf2/read.c83
-rw-r--r--gdb/dwarf2/read.h40
2 files changed, 43 insertions, 80 deletions
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 227ad19..e38a244 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -21653,52 +21653,6 @@ dwarf2_per_objfile::~dwarf2_per_objfile ()
remove_all_cus ();
}
-/* A set of CU "per_cu" pointer, DIE offset, and GDB type pointer.
- We store these in a hash table separate from the DIEs, and preserve them
- when the DIEs are flushed out of cache.
-
- The CU "per_cu" pointer is needed because offset alone is not enough to
- uniquely identify the type. A file may have multiple .debug_types sections,
- or the type may come from a DWO file. Furthermore, while it's more logical
- to use per_cu->section+offset, with Fission the section with the data is in
- the DWO file but we don't know that section at the point we need it.
- We have to use something in dwarf2_per_cu_data (or the pointer to it)
- because we can enter the lookup routine, get_die_type_at_offset, from
- outside this file, and thus won't necessarily have PER_CU->cu.
- Fortunately, PER_CU is stable for the life of the objfile. */
-
-struct dwarf2_per_cu_offset_and_type
-{
- const struct dwarf2_per_cu_data *per_cu;
- sect_offset sect_off;
- struct type *type;
-};
-
-/* Hash function for a dwarf2_per_cu_offset_and_type. */
-
-static hashval_t
-per_cu_offset_and_type_hash (const void *item)
-{
- const struct dwarf2_per_cu_offset_and_type *ofs
- = (const struct dwarf2_per_cu_offset_and_type *) item;
-
- return (uintptr_t) ofs->per_cu + to_underlying (ofs->sect_off);
-}
-
-/* Equality function for a dwarf2_per_cu_offset_and_type. */
-
-static int
-per_cu_offset_and_type_eq (const void *item_lhs, const void *item_rhs)
-{
- const struct dwarf2_per_cu_offset_and_type *ofs_lhs
- = (const struct dwarf2_per_cu_offset_and_type *) item_lhs;
- const struct dwarf2_per_cu_offset_and_type *ofs_rhs
- = (const struct dwarf2_per_cu_offset_and_type *) item_rhs;
-
- return (ofs_lhs->per_cu == ofs_rhs->per_cu
- && ofs_lhs->sect_off == ofs_rhs->sect_off);
-}
-
/* Set the type associated with DIE to TYPE. Save it in CU's hash
table if necessary. For convenience, return TYPE.
@@ -21722,8 +21676,6 @@ set_die_type (struct die_info *die, struct type *type, struct dwarf2_cu *cu,
bool skip_data_location)
{
dwarf2_per_objfile *per_objfile = cu->per_objfile;
- struct dwarf2_per_cu_offset_and_type **slot, ofs;
- struct objfile *objfile = per_objfile->objfile;
struct attribute *attr;
struct dynamic_prop prop;
@@ -21779,24 +21731,13 @@ set_die_type (struct die_info *die, struct type *type, struct dwarf2_cu *cu,
type->add_dyn_prop (DYN_PROP_DATA_LOCATION, prop);
}
- if (per_objfile->die_type_hash == NULL)
- per_objfile->die_type_hash
- = htab_up (htab_create_alloc (127,
- per_cu_offset_and_type_hash,
- per_cu_offset_and_type_eq,
- NULL, xcalloc, xfree));
-
- ofs.per_cu = cu->per_cu;
- ofs.sect_off = die->sect_off;
- ofs.type = type;
- slot = (struct dwarf2_per_cu_offset_and_type **)
- htab_find_slot (per_objfile->die_type_hash.get (), &ofs, INSERT);
- if (*slot)
+ bool inserted
+ = per_objfile->die_type_hash.emplace
+ (per_cu_and_offset {cu->per_cu, die->sect_off}, type).second;
+ if (!inserted)
complaint (_("A problem internal to GDB: DIE %s has type already set"),
sect_offset_str (die->sect_off));
- *slot = XOBNEW (&objfile->objfile_obstack,
- struct dwarf2_per_cu_offset_and_type);
- **slot = ofs;
+
return type;
}
@@ -21808,19 +21749,9 @@ get_die_type_at_offset (sect_offset sect_off,
dwarf2_per_cu_data *per_cu,
dwarf2_per_objfile *per_objfile)
{
- struct dwarf2_per_cu_offset_and_type *slot, ofs;
-
- if (per_objfile->die_type_hash == NULL)
- return NULL;
+ auto it = per_objfile->die_type_hash.find ({per_cu, sect_off});
- ofs.per_cu = per_cu;
- ofs.sect_off = sect_off;
- slot = ((struct dwarf2_per_cu_offset_and_type *)
- htab_find (per_objfile->die_type_hash.get (), &ofs));
- if (slot)
- return slot->type;
- else
- return NULL;
+ return it != per_objfile->die_type_hash.end () ? it->second : nullptr;
}
/* Look up the type for DIE in CU in die_type_hash,
diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
index 40e1f55..c9ef4c7 100644
--- a/gdb/dwarf2/read.h
+++ b/gdb/dwarf2/read.h
@@ -627,6 +627,26 @@ struct type_unit_group_unshareable
struct symtab **symtabs = nullptr;
};
+struct per_cu_and_offset
+{
+ dwarf2_per_cu_data *per_cu;
+ sect_offset offset;
+
+ bool operator== (const per_cu_and_offset &other) const noexcept
+ {
+ return this->per_cu == other.per_cu && this->offset == other.offset;
+ }
+};
+
+struct per_cu_and_offset_hash
+{
+ std::uint64_t operator() (const per_cu_and_offset &key) const noexcept
+ {
+ return (std::hash<dwarf2_per_cu_data *> () (key.per_cu)
+ + std::hash<sect_offset> () (key.offset));
+ }
+};
+
/* Collection of data recorded per objfile.
This hangs off of dwarf2_objfile_data_key.
@@ -701,10 +721,22 @@ struct dwarf2_per_objfile
other objfiles backed by the same BFD. */
struct dwarf2_per_bfd *per_bfd;
- /* Table mapping type DIEs to their struct type *.
- This is nullptr if not allocated yet.
- The mapping is done via (CU/TU + DIE offset) -> type. */
- htab_up die_type_hash;
+ /* A mapping of (CU "per_cu" pointer, DIE offset) to GDB type pointer.
+
+ We store these in a hash table separate from the DIEs, and preserve them
+ when the DIEs are flushed out of cache.
+
+ The CU "per_cu" pointer is needed because offset alone is not enough to
+ uniquely identify the type. A file may have multiple .debug_types sections,
+ or the type may come from a DWO file. Furthermore, while it's more logical
+ to use per_cu->section+offset, with Fission the section with the data is in
+ the DWO file but we don't know that section at the point we need it.
+ We have to use something in dwarf2_per_cu_data (or the pointer to it)
+ because we can enter the lookup routine, get_die_type_at_offset, from
+ outside this file, and thus won't necessarily have PER_CU->cu.
+ Fortunately, PER_CU is stable for the life of the objfile. */
+ gdb::unordered_map<per_cu_and_offset, type *, per_cu_and_offset_hash>
+ die_type_hash;
/* Table containing line_header indexed by offset and offset_in_dwz. */
htab_up line_header_hash;