From: "Christian Biesinger via gdb-patches" <gdb-patches@sourceware.org>
To: gdb-patches@sourceware.org
Cc: Christian Biesinger <cbiesinger@google.com>
Subject: [PATCH v2 1/3] Store the mangled name as a string_view
Date: Tue, 08 Oct 2019 16:09:00 -0000 [thread overview]
Message-ID: <20191008160933.155975-2-cbiesinger@google.com> (raw)
In-Reply-To: <20191008160933.155975-1-cbiesinger@google.com>
This should be a bit faster (because we can compare the size first),
but it is also a dependency for the next patch.
(3.47% of gdb startup time is spent in eq_demangled_name_entry when
attaching to Chrome's content_shell binary)
gdb/ChangeLog:
2019-09-27 Christian Biesinger <cbiesinger@google.com>
* symtab.c (struct demangled_name_entry): Change type of mangled
to gdb::string_view.
(hash_demangled_name_entry): Update.
(eq_demangled_name_entry): Update.
(symbol_set_names): Update.
---
gdb/symtab.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/gdb/symtab.c b/gdb/symtab.c
index 8a551f1575..0724110d12 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -68,6 +68,7 @@
#include "filename-seen-cache.h"
#include "arch-utils.h"
#include <algorithm>
+#include "gdbsupport/gdb_string_view.h"
#include "gdbsupport/pathstuff.h"
/* Forward declarations for local functions. */
@@ -713,7 +714,7 @@ symbol_set_language (struct general_symbol_info *gsymbol,
/* Objects of this type are stored in the demangled name hash table. */
struct demangled_name_entry
{
- const char *mangled;
+ gdb::string_view mangled;
ENUM_BITFIELD(language) language : LANGUAGE_BITS;
char demangled[1];
};
@@ -726,7 +727,7 @@ hash_demangled_name_entry (const void *data)
const struct demangled_name_entry *e
= (const struct demangled_name_entry *) data;
- return htab_hash_string (e->mangled);
+ return iterative_hash (e->mangled.data (), e->mangled.length (), 0);
}
/* Equality function for the demangled name hash. */
@@ -739,7 +740,7 @@ eq_demangled_name_entry (const void *a, const void *b)
const struct demangled_name_entry *db
= (const struct demangled_name_entry *) b;
- return strcmp (da->mangled, db->mangled) == 0;
+ return da->mangled == db->mangled;
}
/* Create the hash table used for demangled names. Each hash entry is
@@ -855,7 +856,7 @@ symbol_set_names (struct general_symbol_info *gsymbol,
else
linkage_name_copy = linkage_name;
- entry.mangled = linkage_name_copy;
+ entry.mangled = gdb::string_view (linkage_name_copy, len);
slot = ((struct demangled_name_entry **)
htab_find_slot (per_bfd->demangled_names_hash.get (),
&entry, INSERT));
@@ -888,7 +889,7 @@ symbol_set_names (struct general_symbol_info *gsymbol,
obstack_alloc (&per_bfd->storage_obstack,
offsetof (struct demangled_name_entry, demangled)
+ demangled_len + 1));
- (*slot)->mangled = linkage_name;
+ (*slot)->mangled = gdb::string_view (linkage_name, len);
}
else
{
@@ -904,7 +905,7 @@ symbol_set_names (struct general_symbol_info *gsymbol,
+ len + demangled_len + 2));
mangled_ptr = &((*slot)->demangled[demangled_len + 1]);
strcpy (mangled_ptr, linkage_name_copy);
- (*slot)->mangled = mangled_ptr;
+ (*slot)->mangled = gdb::string_view (mangled_ptr, len);
}
(*slot)->language = gsymbol->language;
@@ -917,7 +918,7 @@ symbol_set_names (struct general_symbol_info *gsymbol,
|| gsymbol->language == language_auto)
gsymbol->language = (*slot)->language;
- gsymbol->name = (*slot)->mangled;
+ gsymbol->name = (*slot)->mangled.data ();
if ((*slot)->demangled[0] != '\0')
symbol_set_demangled_name (gsymbol, (*slot)->demangled,
&per_bfd->storage_obstack);
--
2.23.0.581.g78d2f28ef7-goog
prev parent reply other threads:[~2019-10-08 16:09 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-08 16:09 [PATCH v2 0/3] Speed up hashing in demangled_names_hash Christian Biesinger via gdb-patches
2019-10-08 16:09 ` [PATCH v2 3/3] Use libxxhash for hashing, if present Christian Biesinger via gdb-patches
2019-10-08 16:09 ` [PATCH v2 2/3] Add a fast_hash function in common-utils Christian Biesinger via gdb-patches
2019-10-08 16:09 ` Christian Biesinger via gdb-patches [this message]
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