From: Tom Tromey <tom@tromey.com>
To: gdb-patches@sourceware.org
Subject: [PATCH v3 02/18] Pre-read DWZ section data
Date: Wed, 22 Nov 2023 22:32:11 -0700 [thread overview]
Message-ID: <20231122-t-bg-dwarf-reading-v3-2-fc3180de63c4@tromey.com> (raw)
In-Reply-To: <20231122-t-bg-dwarf-reading-v3-0-fc3180de63c4@tromey.com>
This changes the DWZ code to pre-read the section data and somewhat
simplify the DWZ API. This makes it easier to add the bfd_cache_close
call to the new dwarf2_read_dwz_file function -- after this is done,
there shouldn't be a reason to keep the BFD's file descriptor open.
---
gdb/dwarf2/dwz.c | 90 +++++++++++++++++++++++++-----------------------------
gdb/dwarf2/dwz.h | 13 ++++++--
gdb/dwarf2/macro.c | 2 --
gdb/dwarf2/read.c | 8 +----
4 files changed, 53 insertions(+), 60 deletions(-)
diff --git a/gdb/dwarf2/dwz.c b/gdb/dwarf2/dwz.c
index edd5b56d778..13f95801ebb 100644
--- a/gdb/dwarf2/dwz.c
+++ b/gdb/dwarf2/dwz.c
@@ -53,49 +53,35 @@ dwz_file::read_string (struct objfile *objfile, LONGEST str_offset)
/* A helper function to find the sections for a .dwz file. */
static void
-locate_dwz_sections (bfd *abfd, asection *sectp, dwz_file *dwz_file)
+locate_dwz_sections (struct objfile *objfile, bfd *abfd, asection *sectp,
+ dwz_file *dwz_file)
{
+ dwarf2_section_info *sect = nullptr;
+
/* Note that we only support the standard ELF names, because .dwz
is ELF-only (at the time of writing). */
if (dwarf2_elf_names.abbrev.matches (sectp->name))
- {
- dwz_file->abbrev.s.section = sectp;
- dwz_file->abbrev.size = bfd_section_size (sectp);
- }
+ sect = &dwz_file->abbrev;
else if (dwarf2_elf_names.info.matches (sectp->name))
- {
- dwz_file->info.s.section = sectp;
- dwz_file->info.size = bfd_section_size (sectp);
- }
+ sect = &dwz_file->info;
else if (dwarf2_elf_names.str.matches (sectp->name))
- {
- dwz_file->str.s.section = sectp;
- dwz_file->str.size = bfd_section_size (sectp);
- }
+ sect = &dwz_file->str;
else if (dwarf2_elf_names.line.matches (sectp->name))
- {
- dwz_file->line.s.section = sectp;
- dwz_file->line.size = bfd_section_size (sectp);
- }
+ sect = &dwz_file->line;
else if (dwarf2_elf_names.macro.matches (sectp->name))
- {
- dwz_file->macro.s.section = sectp;
- dwz_file->macro.size = bfd_section_size (sectp);
- }
+ sect = &dwz_file->macro;
else if (dwarf2_elf_names.gdb_index.matches (sectp->name))
- {
- dwz_file->gdb_index.s.section = sectp;
- dwz_file->gdb_index.size = bfd_section_size (sectp);
- }
+ sect = &dwz_file->gdb_index;
else if (dwarf2_elf_names.debug_names.matches (sectp->name))
- {
- dwz_file->debug_names.s.section = sectp;
- dwz_file->debug_names.size = bfd_section_size (sectp);
- }
+ sect = &dwz_file->debug_names;
else if (dwarf2_elf_names.types.matches (sectp->name))
+ sect = &dwz_file->types;
+
+ if (sect != nullptr)
{
- dwz_file->types.s.section = sectp;
- dwz_file->types.size = bfd_section_size (sectp);
+ sect->s.section = sectp;
+ sect->size = bfd_section_size (sectp);
+ sect->read (objfile);
}
}
@@ -190,20 +176,13 @@ dwz_search_other_debugdirs (std::string &filename, bfd_byte *buildid,
/* See dwz.h. */
-struct dwz_file *
-dwarf2_get_dwz_file (dwarf2_per_bfd *per_bfd, bool require)
+void
+dwarf2_read_dwz_file (dwarf2_per_objfile *per_objfile)
{
bfd_size_type buildid_len_arg;
size_t buildid_len;
bfd_byte *buildid;
-
- if (per_bfd->dwz_file.has_value ())
- {
- dwz_file *result = per_bfd->dwz_file->get ();
- if (require && result == nullptr)
- error (_("could not read '.gnu_debugaltlink' section"));
- return result;
- }
+ dwarf2_per_bfd *per_bfd = per_objfile->per_bfd;
/* This may query the user via the debuginfod support, so it may
only be run in the main thread. */
@@ -219,11 +198,7 @@ dwarf2_get_dwz_file (dwarf2_per_bfd *per_bfd, bool require)
if (data == NULL)
{
if (bfd_get_error () == bfd_error_no_error)
- {
- if (!require)
- return nullptr;
- error (_("could not read '.gnu_debugaltlink' section"));
- }
+ return;
error (_("could not read '.gnu_debugaltlink' section: %s"),
bfd_errmsg (bfd_get_error ()));
}
@@ -292,9 +267,28 @@ dwarf2_get_dwz_file (dwarf2_per_bfd *per_bfd, bool require)
(new struct dwz_file (std::move (dwz_bfd)));
for (asection *sec : gdb_bfd_sections (result->dwz_bfd))
- locate_dwz_sections (result->dwz_bfd.get (), sec, result.get ());
+ locate_dwz_sections (per_objfile->objfile, result->dwz_bfd.get (),
+ sec, result.get ());
gdb_bfd_record_inclusion (per_bfd->obfd, result->dwz_bfd.get ());
+ bfd_cache_close (result->dwz_bfd.get ());
+
per_bfd->dwz_file = std::move (result);
- return per_bfd->dwz_file->get ();
+}
+
+/* See dwz.h. */
+
+struct dwz_file *
+dwarf2_get_dwz_file (dwarf2_per_bfd *per_bfd, bool require)
+{
+ gdb_assert (!require || per_bfd->dwz_file.has_value ());
+
+ dwz_file *result = nullptr;
+ if (per_bfd->dwz_file.has_value ())
+ {
+ result = per_bfd->dwz_file->get ();
+ if (require && result == nullptr)
+ error (_("could not read '.gnu_debugaltlink' section"));
+ }
+ return result;
}
diff --git a/gdb/dwarf2/dwz.h b/gdb/dwarf2/dwz.h
index 5f61b5e1216..a427cda902d 100644
--- a/gdb/dwarf2/dwz.h
+++ b/gdb/dwarf2/dwz.h
@@ -65,13 +65,20 @@ struct dwz_file
const char *read_string (struct objfile *objfile, LONGEST str_offset);
};
-/* Open the separate '.dwz' debug file, if needed. If there is no
+/* Return the separate '.dwz' debug file. If there is no
.gnu_debugaltlink section in the file, then the result depends on
REQUIRE: if REQUIRE is true, then error; if REQUIRE is false,
- return NULL. Always error if there is such a section but the file
- cannot be found. */
+ return NULL. */
extern dwz_file *dwarf2_get_dwz_file (dwarf2_per_bfd *per_bfd,
bool require = false);
+/* Open the separate '.dwz' debug file, if needed. This just sets the
+ appropriate field in the per-BFD structure. If the DWZ file
+ exists, the relevant sections are read in as well. Throws an error
+ if the .gnu_debugaltlink section exists but the file cannot be
+ found. */
+
+extern void dwarf2_read_dwz_file (dwarf2_per_objfile *per_objfile);
+
#endif /* GDB_DWARF2_DWZ_H */
diff --git a/gdb/dwarf2/macro.c b/gdb/dwarf2/macro.c
index 2e88e670216..a63140c7c79 100644
--- a/gdb/dwarf2/macro.c
+++ b/gdb/dwarf2/macro.c
@@ -735,8 +735,6 @@ dwarf_decode_macro_bytes (dwarf2_per_objfile *per_objfile,
dwz_file *dwz = dwarf2_get_dwz_file (per_objfile->per_bfd,
true);
- dwz->macro.read (objfile);
-
include_section = &dwz->macro;
include_bfd = include_section->get_bfd_owner ();
include_mac_end = dwz->macro.buffer + dwz->macro.size;
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 5e9311f1437..1c2f3f62399 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -3212,7 +3212,7 @@ dwarf2_initialize_objfile (struct objfile *objfile)
main thread. */
try
{
- dwarf2_get_dwz_file (per_bfd);
+ dwarf2_read_dwz_file (per_objfile);
}
catch (const gdb_exception_error &err)
{
@@ -5129,12 +5129,6 @@ create_all_units (dwarf2_per_objfile *per_objfile)
dwz_file *dwz = dwarf2_get_dwz_file (per_objfile->per_bfd);
if (dwz != NULL)
{
- /* Pre-read the sections we'll need to construct an index. */
- struct objfile *objfile = per_objfile->objfile;
- dwz->abbrev.read (objfile);
- dwz->info.read (objfile);
- dwz->str.read (objfile);
- dwz->line.read (objfile);
read_comp_units_from_section (per_objfile, &dwz->info, &dwz->abbrev, 1,
types_htab, rcuh_kind::COMPILE);
--
2.41.0
next prev parent reply other threads:[~2023-11-23 5:32 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-23 5:32 [PATCH v3 00/18] Index DWARF in the background Tom Tromey
2023-11-23 5:32 ` [PATCH v3 01/18] Don't use objfile::intern in DWO code Tom Tromey
2023-11-23 5:32 ` Tom Tromey [this message]
2023-11-23 5:32 ` [PATCH v3 03/18] Add a couple of bfd_cache_close calls Tom Tromey
2023-11-23 5:32 ` [PATCH v3 04/18] Add thread-safety to gdb's BFD wrappers Tom Tromey
2023-11-23 5:32 ` [PATCH v3 05/18] Refactor complaint thread-safety approach Tom Tromey
2023-11-23 5:32 ` [PATCH v3 06/18] Add quick_symbol_functions::compute_main_name Tom Tromey
2023-11-23 5:32 ` [PATCH v3 07/18] Add gdb::task_group Tom Tromey
2023-11-23 5:32 ` [PATCH v3 08/18] Move cooked_index_storage to cooked-index.h Tom Tromey
2023-11-23 5:32 ` [PATCH v3 09/18] Add "maint set dwarf synchronous" Tom Tromey
2023-11-23 7:02 ` Eli Zaretskii
2023-11-23 5:32 ` [PATCH v3 10/18] Change how cooked index waits for threads Tom Tromey
2023-11-23 5:32 ` [PATCH v3 11/18] Do more DWARF reading in the background Tom Tromey
2023-11-23 5:32 ` [PATCH v3 12/18] Simplify the public DWARF API Tom Tromey
2023-11-23 5:32 ` [PATCH v3 13/18] Remove two quick_symbol_functions methods Tom Tromey
2023-11-23 5:32 ` [PATCH v3 14/18] Change current_language to be a macro Tom Tromey
2023-11-23 5:32 ` [PATCH v3 15/18] Lazy language setting Tom Tromey
2023-11-23 5:32 ` [PATCH v3 16/18] Optimize lookup_minimal_symbol_text Tom Tromey
2023-11-23 5:32 ` [PATCH v3 17/18] Avoid language-based lookups in startup path Tom Tromey
2023-11-23 5:32 ` [PATCH v3 18/18] Back out some parallel_for_each features Tom Tromey
2023-11-27 15:31 ` [PATCH v3 00/18] Index DWARF in the background Tom de Vries
2023-12-10 17:19 ` Tom Tromey
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