public inbox for gdb-patches@sourceware.org
 help / color / mirror / Atom feed
From: Tom Tromey <tom@tromey.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tom@tromey.com>
Subject: [PATCH v2 21/32] Pre-read DWARF section data
Date: Thu,  4 Nov 2021 12:08:56 -0600	[thread overview]
Message-ID: <20211104180907.2360627-22-tom@tromey.com> (raw)
In-Reply-To: <20211104180907.2360627-1-tom@tromey.com>

Because BFD is not thread-safe, we need to be sure that any section
data that is needed is read before trying to do any DWARF indexing in
the background.

This patch takes a simple approach to this -- it pre-reads the
"info"-related sections.  This is done for the main file, but also any
auxiliary files as well, such as the DWO file.

This patch could be perhaps enhanced by removing some now-redundant
calls to dwarf2_section_info::read.
---
 gdb/dwarf2/read.c | 209 ++++++++++++++++++++--------------------------
 gdb/dwarf2/read.h |   4 +
 2 files changed, 93 insertions(+), 120 deletions(-)

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index f1e389bc5b2..ba804ba5c67 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -2055,6 +2055,25 @@ dwarf2_get_section_info (struct objfile *objfile,
   *sizep = info->size;
 }
 
+/* See dwarf2/read.h.  */
+
+void
+dwarf2_per_bfd::map_info_sections (struct objfile *objfile)
+{
+  info.read (objfile);
+  abbrev.read (objfile);
+  line.read (objfile);
+  str.read (objfile);
+  str_offsets.read (objfile);
+  line_str.read (objfile);
+  ranges.read (objfile);
+  rnglists.read (objfile);
+  addr.read (objfile);
+
+  for (auto &section : types)
+    section.read (objfile);
+}
+
 \f
 /* DWARF quick_symbol_functions support.  */
 
@@ -7799,7 +7818,7 @@ dwarf2_build_psymtabs_hard (dwarf2_per_objfile *per_objfile)
   scoped_restore restore_reading_psyms
     = make_scoped_restore (&per_bfd->reading_partial_symbols, true);
 
-  per_bfd->info.read (objfile);
+  per_bfd->map_info_sections (objfile);
 
   /* Any cached compilation units will be linked by the per-objfile
      read_in_chain.  Make sure to free them when we're done.  */
@@ -12605,69 +12624,47 @@ open_dwo_file (dwarf2_per_objfile *per_objfile,
    size of each of the DWO debugging sections we are interested in.  */
 
 static void
-dwarf2_locate_dwo_sections (bfd *abfd, asection *sectp,
-			    dwo_sections *dwo_sections)
+dwarf2_locate_dwo_sections (struct objfile *objfile, bfd *abfd,
+			    asection *sectp, dwo_sections *dwo_sections)
 {
   const struct dwop_section_names *names = &dwop_section_names;
 
+  struct dwarf2_section_info *dw_sect = nullptr;
+
   if (names->abbrev_dwo.matches (sectp->name))
-    {
-      dwo_sections->abbrev.s.section = sectp;
-      dwo_sections->abbrev.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->abbrev;
   else if (names->info_dwo.matches (sectp->name))
-    {
-      dwo_sections->info.s.section = sectp;
-      dwo_sections->info.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->info;
   else if (names->line_dwo.matches (sectp->name))
-    {
-      dwo_sections->line.s.section = sectp;
-      dwo_sections->line.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->line;
   else if (names->loc_dwo.matches (sectp->name))
-    {
-      dwo_sections->loc.s.section = sectp;
-      dwo_sections->loc.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->loc;
   else if (names->loclists_dwo.matches (sectp->name))
-    {
-      dwo_sections->loclists.s.section = sectp;
-      dwo_sections->loclists.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->loclists;
   else if (names->macinfo_dwo.matches (sectp->name))
-    {
-      dwo_sections->macinfo.s.section = sectp;
-      dwo_sections->macinfo.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->macinfo;
   else if (names->macro_dwo.matches (sectp->name))
-    {
-      dwo_sections->macro.s.section = sectp;
-      dwo_sections->macro.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->macro;
   else if (names->rnglists_dwo.matches (sectp->name))
-    {
-      dwo_sections->rnglists.s.section = sectp;
-      dwo_sections->rnglists.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->rnglists;
   else if (names->str_dwo.matches (sectp->name))
-    {
-      dwo_sections->str.s.section = sectp;
-      dwo_sections->str.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->str;
   else if (names->str_offsets_dwo.matches (sectp->name))
-    {
-      dwo_sections->str_offsets.s.section = sectp;
-      dwo_sections->str_offsets.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwo_sections->str_offsets;
   else if (names->types_dwo.matches (sectp->name))
     {
       struct dwarf2_section_info type_section;
 
       memset (&type_section, 0, sizeof (type_section));
-      type_section.s.section = sectp;
-      type_section.size = bfd_section_size (sectp);
       dwo_sections->types.push_back (type_section);
+      dw_sect = &dwo_sections->types.back ();
+    }
+
+  if (dw_sect != nullptr)
+    {
+      dw_sect->s.section = sectp;
+      dw_sect->size = bfd_section_size (sectp);
+      dw_sect->read (objfile);
     }
 }
 
@@ -12695,8 +12692,8 @@ open_and_init_dwo_file (dwarf2_cu *cu, const char *dwo_name,
   dwo_file->dbfd = std::move (dbfd);
 
   for (asection *sec : gdb_bfd_sections (dwo_file->dbfd))
-    dwarf2_locate_dwo_sections (dwo_file->dbfd.get (), sec,
-				&dwo_file->sections);
+    dwarf2_locate_dwo_sections (per_objfile->objfile, dwo_file->dbfd.get (),
+				sec, &dwo_file->sections);
 
   create_cus_hash_table (per_objfile, cu, *dwo_file, dwo_file->sections.info,
 			 dwo_file->cus);
@@ -12723,8 +12720,8 @@ open_and_init_dwo_file (dwarf2_cu *cu, const char *dwo_name,
    we are interested in.  */
 
 static void
-dwarf2_locate_common_dwp_sections (bfd *abfd, asection *sectp,
-				   dwp_file *dwp_file)
+dwarf2_locate_common_dwp_sections (struct objfile *objfile, bfd *abfd,
+				   asection *sectp, dwp_file *dwp_file)
 {
   const struct dwop_section_names *names = &dwop_section_names;
   unsigned int elf_section_nr = elf_section_data (sectp)->this_idx;
@@ -12735,20 +12732,19 @@ dwarf2_locate_common_dwp_sections (bfd *abfd, asection *sectp,
   dwp_file->elf_sections[elf_section_nr] = sectp;
 
   /* Look for specific sections that we need.  */
+  struct dwarf2_section_info *dw_sect = nullptr;
   if (names->str_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.str.s.section = sectp;
-      dwp_file->sections.str.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.str;
   else if (names->cu_index.matches (sectp->name))
-    {
-      dwp_file->sections.cu_index.s.section = sectp;
-      dwp_file->sections.cu_index.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.cu_index;
   else if (names->tu_index.matches (sectp->name))
+    dw_sect = &dwp_file->sections.tu_index;
+
+  if (dw_sect != nullptr)
     {
-      dwp_file->sections.tu_index.s.section = sectp;
-      dwp_file->sections.tu_index.size = bfd_section_size (sectp);
+      dw_sect->s.section = sectp;
+      dw_sect->size = bfd_section_size (sectp);
+      dw_sect->read (objfile);
     }
 }
 
@@ -12758,7 +12754,8 @@ dwarf2_locate_common_dwp_sections (bfd *abfd, asection *sectp,
    have version 1 or 2 or 5 until we parse the cu_index/tu_index sections.  */
 
 static void
-dwarf2_locate_v2_dwp_sections (bfd *abfd, asection *sectp, void *dwp_file_ptr)
+dwarf2_locate_v2_dwp_sections (struct objfile *objfile, bfd *abfd,
+			       asection *sectp, void *dwp_file_ptr)
 {
   struct dwp_file *dwp_file = (struct dwp_file *) dwp_file_ptr;
   const struct dwop_section_names *names = &dwop_section_names;
@@ -12770,45 +12767,29 @@ dwarf2_locate_v2_dwp_sections (bfd *abfd, asection *sectp, void *dwp_file_ptr)
   dwp_file->elf_sections[elf_section_nr] = sectp;
 
   /* Look for specific sections that we need.  */
+  struct dwarf2_section_info *dw_sect = nullptr;
   if (names->abbrev_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.abbrev.s.section = sectp;
-      dwp_file->sections.abbrev.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.abbrev;
   else if (names->info_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.info.s.section = sectp;
-      dwp_file->sections.info.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.info;
   else if (names->line_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.line.s.section = sectp;
-      dwp_file->sections.line.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.line;
   else if (names->loc_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.loc.s.section = sectp;
-      dwp_file->sections.loc.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.loc;
   else if (names->macinfo_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.macinfo.s.section = sectp;
-      dwp_file->sections.macinfo.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.macinfo;
   else if (names->macro_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.macro.s.section = sectp;
-      dwp_file->sections.macro.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.macro;
   else if (names->str_offsets_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.str_offsets.s.section = sectp;
-      dwp_file->sections.str_offsets.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.str_offsets;
   else if (names->types_dwo.matches (sectp->name))
+    dw_sect = &dwp_file->sections.types;
+
+  if (dw_sect != nullptr)
     {
-      dwp_file->sections.types.s.section = sectp;
-      dwp_file->sections.types.size = bfd_section_size (sectp);
+      dw_sect->s.section = sectp;
+      dw_sect->size = bfd_section_size (sectp);
+      dw_sect->read (objfile);
     }
 }
 
@@ -12818,7 +12799,8 @@ dwarf2_locate_v2_dwp_sections (bfd *abfd, asection *sectp, void *dwp_file_ptr)
    have version 1 or 2 or 5 until we parse the cu_index/tu_index sections.  */
 
 static void
-dwarf2_locate_v5_dwp_sections (bfd *abfd, asection *sectp, void *dwp_file_ptr)
+dwarf2_locate_v5_dwp_sections (struct objfile *objfile, bfd *abfd,
+			       asection *sectp, void *dwp_file_ptr)
 {
   struct dwp_file *dwp_file = (struct dwp_file *) dwp_file_ptr;
   const struct dwop_section_names *names = &dwop_section_names;
@@ -12830,40 +12812,27 @@ dwarf2_locate_v5_dwp_sections (bfd *abfd, asection *sectp, void *dwp_file_ptr)
   dwp_file->elf_sections[elf_section_nr] = sectp;
 
   /* Look for specific sections that we need.  */
+  struct dwarf2_section_info *dw_sect = nullptr;
   if (names->abbrev_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.abbrev.s.section = sectp;
-      dwp_file->sections.abbrev.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.abbrev;
   else if (names->info_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.info.s.section = sectp;
-      dwp_file->sections.info.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.info;
   else if (names->line_dwo.matches (sectp->name))
-   {
-     dwp_file->sections.line.s.section = sectp;
-     dwp_file->sections.line.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.line;
   else if (names->loclists_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.loclists.s.section = sectp;
-      dwp_file->sections.loclists.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.loclists;
   else if (names->macro_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.macro.s.section = sectp;
-      dwp_file->sections.macro.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.macro;
   else if (names->rnglists_dwo.matches (sectp->name))
-    {
-      dwp_file->sections.rnglists.s.section = sectp;
-      dwp_file->sections.rnglists.size = bfd_section_size (sectp);
-    }
+    dw_sect = &dwp_file->sections.rnglists;
   else if (names->str_offsets_dwo.matches (sectp->name))
+    dw_sect = &dwp_file->sections.str_offsets;
+
+  if (dw_sect != nullptr)
     {
-      dwp_file->sections.str_offsets.s.section = sectp;
-      dwp_file->sections.str_offsets.size = bfd_section_size (sectp);
+      dw_sect->s.section = sectp;
+      dw_sect->size = bfd_section_size (sectp);
+      dw_sect->read (objfile);
     }
 }
 
@@ -12990,7 +12959,7 @@ open_and_init_dwp_file (dwarf2_per_objfile *per_objfile)
 		    dwp_file->num_sections, asection *);
 
   for (asection *sec : gdb_bfd_sections (dwp_file->dbfd))
-    dwarf2_locate_common_dwp_sections (dwp_file->dbfd.get (), sec,
+    dwarf2_locate_common_dwp_sections (objfile, dwp_file->dbfd.get (), sec,
 				       dwp_file.get ());
 
   dwp_file->cus = create_dwp_hash_table (per_objfile, dwp_file.get (), 0);
@@ -13020,10 +12989,10 @@ open_and_init_dwp_file (dwarf2_per_objfile *per_objfile)
   for (asection *sec : gdb_bfd_sections (dwp_file->dbfd))
     {
       if (dwp_file->version == 2)
-	dwarf2_locate_v2_dwp_sections (dwp_file->dbfd.get (), sec,
+	dwarf2_locate_v2_dwp_sections (objfile, dwp_file->dbfd.get (), sec,
 				       dwp_file.get ());
       else
-	dwarf2_locate_v5_dwp_sections (dwp_file->dbfd.get (), sec,
+	dwarf2_locate_v5_dwp_sections (objfile, dwp_file->dbfd.get (), sec,
 				       dwp_file.get ());
     }
 
diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
index 3717d063fb0..3b29a0a2a73 100644
--- a/gdb/dwarf2/read.h
+++ b/gdb/dwarf2/read.h
@@ -361,6 +361,10 @@ struct dwarf2_per_bfd
      is allocated on the dwarf2_per_bfd obstack.  */
   signatured_type_up allocate_signatured_type (ULONGEST signature);
 
+  /* Map all the DWARF section data needed when scanning
+     .debug_info.  */
+  void map_info_sections (struct objfile *objfile);
+
 private:
   /* This function is mapped across the sections and remembers the
      offset and size of each of the debugging sections we are
-- 
2.31.1


  parent reply	other threads:[~2021-11-04 18:09 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-04 18:08 [PATCH v2 00/32] Rewrite the DWARF "partial" reader Tom Tromey
2021-11-04 18:08 ` [PATCH v2 01/32] Introduce make_unique_xstrndup Tom Tromey
2021-11-05 19:20   ` Simon Marchi
2021-11-05 20:08     ` Tom Tromey
2021-11-04 18:08 ` [PATCH v2 02/32] Split create_addrmap_from_aranges Tom Tromey
2021-11-04 18:08 ` [PATCH v2 03/32] Add dwarf2_per_cu_data::addresses_seen Tom Tromey
2021-11-04 18:08 ` [PATCH v2 04/32] Refactor dwarf2_get_pc_bounds Tom Tromey
2021-11-05 19:51   ` Simon Marchi
2021-11-24 15:53     ` Tom Tromey
2021-11-04 18:08 ` [PATCH v2 05/32] Allow ada_decode not to decode operators Tom Tromey
2021-11-04 18:08 ` [PATCH v2 06/32] Let skip_one_die not skip children Tom Tromey
2021-11-04 18:08 ` [PATCH v2 07/32] Add name splitting Tom Tromey
2021-11-04 18:08 ` [PATCH v2 08/32] Add new overload of dwarf5_djb_hash Tom Tromey
2021-11-05 20:01   ` Simon Marchi
2021-11-07 17:02     ` Tom Tromey
2021-11-04 18:08 ` [PATCH v2 09/32] Refactor build_type_psymtabs_reader Tom Tromey
2021-11-04 18:08 ` [PATCH v2 10/32] Add batching parameter to parallel_for_each Tom Tromey
2021-11-04 18:08 ` [PATCH v2 11/32] Return vector of results from parallel_for_each Tom Tromey
2021-11-17 20:37   ` Lancelot SIX
2021-11-18 14:41     ` Tom Tromey
2021-11-04 18:08 ` [PATCH v2 12/32] Specialize std::hash for gdb_exception Tom Tromey
2021-11-04 18:08 ` [PATCH v2 13/32] Introduce DWARF abbrev cache Tom Tromey
2021-11-04 18:08 ` [PATCH v2 14/32] Statically examine abbrev properties Tom Tromey
2021-11-04 18:08 ` [PATCH v2 15/32] Update skip_one_die for new " Tom Tromey
2021-11-04 18:08 ` [PATCH v2 16/32] Introduce the new DWARF index class Tom Tromey
2021-11-04 18:08 ` [PATCH v2 17/32] The new DWARF indexer Tom Tromey
2021-11-04 18:08 ` [PATCH v2 18/32] Implement quick_symbol_functions for cooked DWARF index Tom Tromey
2021-11-04 18:08 ` [PATCH v2 19/32] Wire in the new DWARF indexer Tom Tromey
2021-11-04 18:08 ` [PATCH v2 20/32] Introduce thread-safe handling for complaints Tom Tromey
2021-11-04 18:08 ` Tom Tromey [this message]
2021-11-04 18:08 ` [PATCH v2 22/32] Parallelize DWARF indexing Tom Tromey
2021-11-04 18:08 ` [PATCH v2 23/32] "Finalize" the DWARF index in the background Tom Tromey
2021-11-04 18:08 ` [PATCH v2 24/32] Rename write_psymtabs_to_index Tom Tromey
2021-11-04 18:09 ` [PATCH v2 25/32] Change the key type in psym_index_map Tom Tromey
2021-11-04 18:09 ` [PATCH v2 26/32] Change parameters to write_address_map Tom Tromey
2021-11-04 18:09 ` [PATCH v2 27/32] Genericize addrmap handling in the DWARF index writer Tom Tromey
2021-11-04 18:09 ` [PATCH v2 28/32] Adapt .gdb_index writer to new DWARF scanner Tom Tromey
2021-11-04 18:09 ` [PATCH v2 29/32] Adapt .debug_names " Tom Tromey
2021-11-04 18:09 ` [PATCH v2 30/32] Enable the new DWARF indexer Tom Tromey
2021-11-04 18:09 ` [PATCH v2 31/32] Delete DWARF psymtab code Tom Tromey
2021-11-04 18:09 ` [PATCH v2 32/32] Remove dwarf2_per_cu_data::v Tom Tromey
2021-11-06 12:25 ` [PATCH v2 00/32] Rewrite the DWARF "partial" reader Tom de Vries
2021-11-11 12:23   ` Tom de Vries
2021-11-16 23:56   ` Tom Tromey
2021-11-17  9:22     ` Tom de Vries
2021-11-18 14:43     ` Tom Tromey
2021-11-22 19:59     ` Tom Tromey
2021-11-22 20:52       ` Tom de Vries
2021-11-22 22:11         ` Tom Tromey
2021-11-23  7:56           ` Tom de Vries
2021-11-23 17:00             ` Tom Tromey
2021-11-08 17:41 ` Simon Marchi
2021-11-10 19:56   ` Tom Tromey

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211104180907.2360627-22-tom@tromey.com \
    --to=tom@tromey.com \
    --cc=gdb-patches@sourceware.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).