[PATCH v3 1/7] gdb/dwarf: move dwo_unit and dwo_file to dwo.h

[Simon Marchi <simon.marchi@efficios.com>]

From: Simon Marchi <simon.marchi@polymtl.ca>

Move these types and some related things to a new dwo.h header file.  My
goal is to allow index-write.c to see these types, in a later patch.  I
initially moved them to read.h, but Tom suggested in review that read.h
was getting a bit too large.

Change-Id: Ia32e0643f95561d3a1bfb67d501c8e20f5682f0e
---
 gdb/dwarf2/dwo.h  | 219 ++++++++++++++++++++++++++++++++++++++++++++++
 gdb/dwarf2/read.c | 170 +----------------------------------
 gdb/dwarf2/read.h |  44 +---------
 3 files changed, 221 insertions(+), 212 deletions(-)
 create mode 100644 gdb/dwarf2/dwo.h

diff --git a/gdb/dwarf2/dwo.h b/gdb/dwarf2/dwo.h
new file mode 100644
index 000000000000..025932b1e969
--- /dev/null
+++ b/gdb/dwarf2/dwo.h
@@ -0,0 +1,219 @@
+/* DWARF 2 debugging format support for GDB.
+
+   Copyright (C) 1994-2026 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef GDB_DWARF2_DWO_H
+#define GDB_DWARF2_DWO_H
+
+#include "dwarf2/section.h"
+#include "gdb_bfd.h"
+#include "gdbsupport/unordered_set.h"
+#include "hashtab.h"
+
+/* These sections are what may appear in a (real or virtual) DWO file.  */
+
+struct dwo_sections
+{
+  struct dwarf2_section_info abbrev;
+  struct dwarf2_section_info line;
+  struct dwarf2_section_info loc;
+  struct dwarf2_section_info loclists;
+  struct dwarf2_section_info macinfo;
+  struct dwarf2_section_info macro;
+  struct dwarf2_section_info rnglists;
+  struct dwarf2_section_info str;
+  struct dwarf2_section_info str_offsets;
+  /* In the case of a virtual DWO file, these two are unused.  */
+  std::vector<dwarf2_section_info> infos;
+  std::vector<dwarf2_section_info> types;
+};
+
+/* CUs/TUs in DWP/DWO files.  */
+
+struct dwo_unit
+{
+  /* Backlink to the containing struct dwo_file.  */
+  struct dwo_file *dwo_file = nullptr;
+
+  /* The "id" that distinguishes this CU/TU.
+     .debug_info calls this "dwo_id", .debug_types calls this "signature".
+     Since signatures came first, we stick with it for consistency.  */
+  ULONGEST signature = 0;
+
+  /* The section this CU/TU lives in, in the DWO file.  */
+  dwarf2_section_info *section = nullptr;
+
+  /* This is set if SECTION is owned by this dwo_unit.  */
+  dwarf2_section_info_up section_holder;
+
+  /* Same as dwarf2_per_cu::{sect_off,length} but in the DWO section.  */
+  sect_offset sect_off {};
+  unsigned int length = 0;
+
+  /* For types, offset in the type's DIE of the type defined by this TU.  */
+  cu_offset type_offset_in_tu;
+};
+
+using dwo_unit_up = std::unique_ptr<dwo_unit>;
+
+/* Hash function for dwo_unit objects, based on the signature.  */
+
+struct dwo_unit_hash
+{
+  using is_transparent = void;
+
+  std::size_t operator() (ULONGEST signature) const noexcept
+  { return signature; }
+
+  std::size_t operator() (const dwo_unit_up &unit) const noexcept
+  { return (*this) (unit->signature); }
+};
+
+/* Equal function for dwo_unit objects, based on the signature.
+
+   The signature is assumed to be unique within the DWO file.  So while object
+   file CU dwo_id's always have the value zero, that's OK, assuming each object
+   file DWO file has only one CU, and that's the rule for now.  */
+
+struct dwo_unit_eq
+{
+  using is_transparent = void;
+
+  bool operator() (ULONGEST sig, const dwo_unit_up  &unit) const noexcept
+  { return sig == unit->signature; }
+
+  bool operator() (const dwo_unit_up &a, const dwo_unit_up &b) const noexcept
+  { return (*this) (a->signature, b); }
+};
+
+/* Set of dwo_unit object, using their signature as identity.  */
+
+using dwo_unit_set = gdb::unordered_set<dwo_unit_up, dwo_unit_hash, dwo_unit_eq>;
+
+/* Data for one DWO file.
+
+   This includes virtual DWO files (a virtual DWO file is a DWO file as it
+   appears in a DWP file).  DWP files don't really have DWO files per se -
+   comdat folding of types "loses" the DWO file they came from, and from
+   a high level view DWP files appear to contain a mass of random types.
+   However, to maintain consistency with the non-DWP case we pretend DWP
+   files contain virtual DWO files, and we assign each TU with one virtual
+   DWO file (generally based on the line and abbrev section offsets -
+   a heuristic that seems to work in practice).  */
+
+struct dwo_file
+{
+  dwo_file () = default;
+  DISABLE_COPY_AND_ASSIGN (dwo_file);
+
+  /* The DW_AT_GNU_dwo_name or DW_AT_dwo_name attribute.
+     For virtual DWO files the name is constructed from the section offsets
+     of abbrev,line,loc,str_offsets so that we combine virtual DWO files
+     from related CU+TUs.  */
+  std::string dwo_name;
+
+  /* The DW_AT_comp_dir attribute.  */
+  const char *comp_dir = nullptr;
+
+  /* The bfd, when the file is open.  Otherwise this is NULL.
+     This is unused(NULL) for virtual DWO files where we use dwp_file.dbfd.  */
+  gdb_bfd_ref_ptr dbfd;
+
+  /* The sections that make up this DWO file.
+     Remember that for virtual DWO files in DWP V2 or DWP V5, these are virtual
+     sections (for lack of a better name).  */
+  struct dwo_sections sections {};
+
+  /* The CUs in the file.
+
+     Multiple CUs per DWO are supported as an extension to handle LLVM's Link
+     Time Optimization output (where multiple source files may be compiled into
+     a single object/dwo pair).  */
+  dwo_unit_set cus;
+
+  /* Table of TUs in the file.  */
+  dwo_unit_set tus;
+};
+
+using dwo_file_up = std::unique_ptr<dwo_file>;
+
+/* This is used when looking up entries in a dwo_file_set.  */
+
+struct dwo_file_search
+{
+  /* Name of the DWO to look for.  */
+  const char *dwo_name;
+
+  /* Compilation directory to look for.  */
+  const char *comp_dir;
+};
+
+/* Hash function for dwo_file objects, using their dwo_name and comp_dir as
+   identity.  */
+
+struct dwo_file_hash
+{
+  using is_transparent = void;
+
+  std::size_t operator() (const dwo_file_search &search) const noexcept
+  {
+    hashval_t hash = htab_hash_string (search.dwo_name);
+
+    if (search.comp_dir != nullptr)
+      hash += htab_hash_string (search.comp_dir);
+
+    return hash;
+  }
+
+  std::size_t operator() (const dwo_file_up &file) const noexcept
+  {
+    return (*this) ({ file->dwo_name.c_str (), file->comp_dir });
+  }
+};
+
+/* Equal function for dwo_file objects, using their dwo_name and comp_dir as
+   identity.  */
+
+struct dwo_file_eq
+{
+  using is_transparent = void;
+
+  bool operator() (const dwo_file_search &search,
+		   const dwo_file_up &dwo_file) const noexcept
+  {
+    if (search.dwo_name != dwo_file->dwo_name)
+      return false;
+
+    if (search.comp_dir == nullptr || dwo_file->comp_dir == nullptr)
+      return search.comp_dir == dwo_file->comp_dir;
+
+    return streq (search.comp_dir, dwo_file->comp_dir);
+  }
+
+  bool operator() (const dwo_file_up &a, const dwo_file_up &b) const noexcept
+  {
+    return (*this) ({ a->dwo_name.c_str (), a->comp_dir }, b);
+  }
+};
+
+/* Set of dwo_file objects, using their dwo_name and comp_dir as identity.  */
+
+using dwo_file_up_set
+  = gdb::unordered_set<dwo_file_up, dwo_file_hash, dwo_file_eq>;
+
+#endif /* GDB_DWARF2_DWO_H */
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index efe96f6510da..46aa0201cc63 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -31,6 +31,7 @@
 #include "dwarf2/abbrev.h"
 #include "dwarf2/aranges.h"
 #include "dwarf2/attribute.h"
+#include "dwarf2/dwo.h"
 #include "dwarf2/unit-head.h"
 #include "dwarf2/cooked-index-worker.h"
 #include "dwarf2/cooked-indexer.h"
@@ -65,7 +66,6 @@
 #include "dwarf2/expr.h"
 #include "dwarf2/loc.h"
 #include "cp-support.h"
-#include "hashtab.h"
 #include "command.h"
 #include "cli/cli-cmds.h"
 #include "block.h"
@@ -266,86 +266,6 @@ struct loclists_rnglists_header
   unsigned int offset_entry_count;
 };
 
-/* These sections are what may appear in a (real or virtual) DWO file.  */
-
-struct dwo_sections
-{
-  struct dwarf2_section_info abbrev;
-  struct dwarf2_section_info line;
-  struct dwarf2_section_info loc;
-  struct dwarf2_section_info loclists;
-  struct dwarf2_section_info macinfo;
-  struct dwarf2_section_info macro;
-  struct dwarf2_section_info rnglists;
-  struct dwarf2_section_info str;
-  struct dwarf2_section_info str_offsets;
-  /* In the case of a virtual DWO file, these two are unused.  */
-  std::vector<dwarf2_section_info> infos;
-  std::vector<dwarf2_section_info> types;
-};
-
-/* CUs/TUs in DWP/DWO files.  */
-
-struct dwo_unit
-{
-  /* Backlink to the containing struct dwo_file.  */
-  struct dwo_file *dwo_file = nullptr;
-
-  /* The "id" that distinguishes this CU/TU.
-     .debug_info calls this "dwo_id", .debug_types calls this "signature".
-     Since signatures came first, we stick with it for consistency.  */
-  ULONGEST signature = 0;
-
-  /* The section this CU/TU lives in, in the DWO file.  */
-  dwarf2_section_info *section = nullptr;
-
-  /* This is set if SECTION is owned by this dwo_unit.  */
-  dwarf2_section_info_up section_holder;
-
-  /* Same as dwarf2_per_cu::{sect_off,length} but in the DWO section.  */
-  sect_offset sect_off {};
-  unsigned int length = 0;
-
-  /* For types, offset in the type's DIE of the type defined by this TU.  */
-  cu_offset type_offset_in_tu;
-};
-
-using dwo_unit_up = std::unique_ptr<dwo_unit>;
-
-/* Hash function for dwo_unit objects, based on the signature.  */
-
-struct dwo_unit_hash
-{
-  using is_transparent = void;
-
-  std::size_t operator() (ULONGEST signature) const noexcept
-  { return signature; }
-
-  std::size_t operator() (const dwo_unit_up &unit) const noexcept
-  { return (*this) (unit->signature); }
-};
-
-/* Equal function for dwo_unit objects, based on the signature.
-
-   The signature is assumed to be unique within the DWO file.  So while object
-   file CU dwo_id's always have the value zero, that's OK, assuming each object
-   file DWO file has only one CU, and that's the rule for now.  */
-
-struct dwo_unit_eq
-{
-  using is_transparent = void;
-
-  bool operator() (ULONGEST sig, const dwo_unit_up  &unit) const noexcept
-  { return sig == unit->signature; }
-
-  bool operator() (const dwo_unit_up &a, const dwo_unit_up &b) const noexcept
-  { return (*this) (a->signature, b); }
-};
-
-/* Set of dwo_unit object, using their signature as identity.  */
-
-using dwo_unit_set = gdb::unordered_set<dwo_unit_up, dwo_unit_hash, dwo_unit_eq>;
-
 /* include/dwarf2.h defines the DWP section codes.
    It defines a max value but it doesn't define a min value, which we
    use for error checking, so provide one.  */
@@ -355,94 +275,6 @@ enum dwp_v2_section_ids
   DW_SECT_MIN = 1
 };
 
-/* Data for one DWO file.
-
-   This includes virtual DWO files (a virtual DWO file is a DWO file as it
-   appears in a DWP file).  DWP files don't really have DWO files per se -
-   comdat folding of types "loses" the DWO file they came from, and from
-   a high level view DWP files appear to contain a mass of random types.
-   However, to maintain consistency with the non-DWP case we pretend DWP
-   files contain virtual DWO files, and we assign each TU with one virtual
-   DWO file (generally based on the line and abbrev section offsets -
-   a heuristic that seems to work in practice).  */
-
-struct dwo_file
-{
-  dwo_file () = default;
-  DISABLE_COPY_AND_ASSIGN (dwo_file);
-
-  /* The DW_AT_GNU_dwo_name or DW_AT_dwo_name attribute.
-     For virtual DWO files the name is constructed from the section offsets
-     of abbrev,line,loc,str_offsets so that we combine virtual DWO files
-     from related CU+TUs.  */
-  std::string dwo_name;
-
-  /* The DW_AT_comp_dir attribute.  */
-  const char *comp_dir = nullptr;
-
-  /* The bfd, when the file is open.  Otherwise this is NULL.
-     This is unused(NULL) for virtual DWO files where we use dwp_file.dbfd.  */
-  gdb_bfd_ref_ptr dbfd;
-
-  /* The sections that make up this DWO file.
-     Remember that for virtual DWO files in DWP V2 or DWP V5, these are virtual
-     sections (for lack of a better name).  */
-  struct dwo_sections sections {};
-
-  /* The CUs in the file.
-
-     Multiple CUs per DWO are supported as an extension to handle LLVM's Link
-     Time Optimization output (where multiple source files may be compiled into
-     a single object/dwo pair).  */
-  dwo_unit_set cus;
-
-  /* Table of TUs in the file.  */
-  dwo_unit_set tus;
-};
-
-/* See dwarf2/read.h.  */
-
-std::size_t
-dwo_file_hash::operator() (const dwo_file_search &search) const noexcept
-{
-  hashval_t hash = htab_hash_string (search.dwo_name);
-
-  if (search.comp_dir != nullptr)
-    hash += htab_hash_string (search.comp_dir);
-
-  return hash;
-}
-
-/* See dwarf2/read.h.  */
-
-std::size_t
-dwo_file_hash::operator() (const dwo_file_up &file) const noexcept
-{
-  return (*this) ({ file->dwo_name.c_str (), file->comp_dir });
-}
-
-/* See dwarf2/read.h.  */
-
-bool
-dwo_file_eq::operator() (const dwo_file_search &search,
-			 const dwo_file_up &dwo_file) const noexcept
-{
-  if (search.dwo_name != dwo_file->dwo_name)
-    return false;
-
-  if (search.comp_dir == nullptr || dwo_file->comp_dir == nullptr)
-    return search.comp_dir == dwo_file->comp_dir;
-
-  return streq (search.comp_dir, dwo_file->comp_dir);
-}
-
-/* See dwarf2/read.h.  */
-
-bool
-dwo_file_eq::operator() (const dwo_file_up &a,
-			 const dwo_file_up &b) const noexcept
-{ return (*this) ({ a->dwo_name.c_str (), a->comp_dir }, b); }
-
 /* These sections are what may appear in a DWP file.  */
 
 struct dwp_sections
diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
index c65ee7f86990..63c3129ad9a8 100644
--- a/gdb/dwarf2/read.h
+++ b/gdb/dwarf2/read.h
@@ -22,6 +22,7 @@
 
 #include <queue>
 #include "dwarf2/abbrev.h"
+#include "dwarf2/dwo.h"
 #include "dwarf2/unit-head.h"
 #include "dwarf2/file-and-dir.h"
 #include "dwarf2/index-cache.h"
@@ -529,49 +530,6 @@ using signatured_type_set
   = gdb::unordered_set<signatured_type *, signatured_type_hash,
 		       signatured_type_eq>;
 
-struct dwo_file;
-
-using dwo_file_up = std::unique_ptr<dwo_file>;
-
-/* This is used when looking up entries in a dwo_file_set.  */
-
-struct dwo_file_search
-{
-  /* Name of the DWO to look for.  */
-  const char *dwo_name;
-
-  /* Compilation directory to look for.  */
-  const char *comp_dir;
-};
-
-/* Hash function for dwo_file objects, using their dwo_name and comp_dir as
-   identity.  */
-
-struct dwo_file_hash
-{
-  using is_transparent = void;
-
-  std::size_t operator() (const dwo_file_search &search) const noexcept;
-  std::size_t operator() (const dwo_file_up &file) const noexcept;
-};
-
-/* Equal function for dwo_file objects, using their dwo_name and comp_dir as
-   identity.  */
-
-struct dwo_file_eq
-{
-  using is_transparent = void;
-
-  bool operator() (const dwo_file_search &search,
-		   const dwo_file_up &dwo_file) const noexcept;
-  bool operator() (const dwo_file_up &a, const dwo_file_up &b) const noexcept;
-};
-
-/* Set of dwo_file objects, using their dwo_name and comp_dir as identity.  */
-
-using dwo_file_up_set
-  = gdb::unordered_set<dwo_file_up, dwo_file_hash, dwo_file_eq>;
-
 struct dwp_file;
 
 using dwp_file_up = std::unique_ptr<dwp_file>;
-- 
2.54.0