From bb3f8ae2902a9878a25fad21efd23fe0f888c232 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Sun, 28 Nov 2021 10:48:53 -0700 Subject: [PATCH] Move file_and_directory to new file and C++-ize This moves file_and_directory to a new file, and then C++-izes it -- replacing direct assignments with methods, and arranging for it to own any string that must be computed. Finally, the CU's objfile will only be used on demand; this is an important property for the new DWARF indexer's parallel mode. --- gdb/dwarf2/file-and-dir.h | 107 ++++++++++++++++++++++++++++++++++++++ gdb/dwarf2/read.c | 67 ++++++++---------------- 2 files changed, 129 insertions(+), 45 deletions(-) create mode 100644 gdb/dwarf2/file-and-dir.h diff --git a/gdb/dwarf2/file-and-dir.h b/gdb/dwarf2/file-and-dir.h new file mode 100644 index 00000000000..1a9ccf35829 --- /dev/null +++ b/gdb/dwarf2/file-and-dir.h @@ -0,0 +1,107 @@ +/* DWARF file and directory + + Copyright (C) 1994-2021 Free Software Foundation, Inc. + + Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology, + Inc. with support from Florida State University (under contract + with the Ada Joint Program Office), and Silicon Graphics, Inc. + Initial contribution by Brent Benson, Harris Computer Systems, Inc., + based on Fred Fish's (Cygnus Support) implementation of DWARF 1 + support. + + 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 . */ + +#ifndef GDB_DWARF2_FILE_AND_DIR_H +#define GDB_DWARF2_FILE_AND_DIR_H + +#include "objfiles.h" +#include + +/* The return type of find_file_and_directory. Note, the enclosed + string pointers are only valid while this object is valid. */ + +struct file_and_directory +{ + file_and_directory (const char *name, const char *dir) + : m_name (name), + m_comp_dir (dir) + { + } + + /* Return true if the file name is unknown. */ + bool is_unknown () const + { + return m_name == nullptr; + } + + /* Set the compilation directory. */ + void set_comp_dir (std::string &&dir) + { + m_comp_dir_storage = std::move (dir); + m_comp_dir = nullptr; + } + + /* Fetch the compilation directory. This may return NULL in some + circumstances. Note that the return value here is not stable -- + it may change if this object is moved. To get a stable pointer, + you should call intern_comp_dir. */ + const char *get_comp_dir () const + { + if (!m_comp_dir_storage.empty ()) + return m_comp_dir_storage.c_str (); + return m_comp_dir; + } + + /* If necessary, intern the compilation directory using OBJFILE's + string cache. Returns the compilation directory. */ + const char *intern_comp_dir (struct objfile *objfile) + { + if (!m_comp_dir_storage.empty ()) + { + m_comp_dir = objfile->intern (m_comp_dir_storage); + m_comp_dir_storage.clear (); + } + return m_comp_dir; + } + + /* Fetch the filename. This never returns NULL. */ + const char *get_name () const + { + return m_name == nullptr ? "" : m_name; + } + + /* Set the filename. */ + void set_name (const char *name) + { + m_name = name; + } + +private: + + /* The filename. */ + const char *m_name; + + /* The compilation directory. NULL if not known. If we needed to + compute a new string, it will be stored in the comp_dir_storage + member, and this will be NULL. Otherwise, points directly to the + DW_AT_comp_dir string attribute. */ + const char *m_comp_dir; + + /* The compilation directory, if it needed to be allocated. */ + std::string m_comp_dir_storage; +}; + +#endif /* GDB_DWARF2_FILE_AND_DIR_H */ diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 3cf0c9ea2a8..a2ed2cdc16d 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -34,6 +34,7 @@ #include "dwarf2/attribute.h" #include "dwarf2/comp-unit-head.h" #include "dwarf2/cu.h" +#include "dwarf2/file-and-dir.h" #include "dwarf2/index-cache.h" #include "dwarf2/index-common.h" #include "dwarf2/leb.h" @@ -1206,7 +1207,6 @@ static struct die_info *die_specification (struct die_info *die, static line_header_up dwarf_decode_line_header (sect_offset sect_off, struct dwarf2_cu *cu); -struct file_and_directory; static void dwarf_decode_lines (struct line_header *, const file_and_directory &, struct dwarf2_cu *, dwarf2_psymtab *, @@ -1538,21 +1538,6 @@ dwarf2_per_cu_data_deleter::operator() (dwarf2_per_cu_data *data) delete data; } -/* The return type of find_file_and_directory. Note, the enclosed - string pointers are only valid while this object is valid. */ - -struct file_and_directory -{ - /* The filename. This is never NULL. */ - const char *name; - - /* The compilation directory. NULL if not known. If we needed to - compute a new string, it will be stored in the per-BFD string - bcache; otherwise, points directly to the DW_AT_comp_dir string - attribute owned by the obstack that owns the DIE. */ - const char *comp_dir; -}; - static file_and_directory find_file_and_directory (struct die_info *die, struct dwarf2_cu *cu); @@ -3024,7 +3009,7 @@ dw2_get_file_names_reader (const struct die_reader_specs *reader, file_and_directory fnd = find_file_and_directory (comp_unit_die, cu); int offset = 0; - if (strcmp (fnd.name, "") != 0) + if (fnd.is_unknown ()) ++offset; else if (lh == nullptr) return; @@ -3053,12 +3038,12 @@ dw2_get_file_names_reader (const struct die_reader_specs *reader, } qfn->num_file_names = offset + include_names.size (); - qfn->comp_dir = fnd.comp_dir; + qfn->comp_dir = fnd.intern_comp_dir (per_objfile->objfile); qfn->file_names = XOBNEWVEC (&per_objfile->per_bfd->obstack, const char *, qfn->num_file_names); if (offset != 0) - qfn->file_names[0] = xstrdup (fnd.name); + qfn->file_names[0] = xstrdup (fnd.get_name ()); if (!include_names.empty ()) memcpy (&qfn->file_names[offset], include_names.data (), @@ -7005,15 +6990,15 @@ process_psymtab_comp_unit_reader (const struct die_reader_specs *reader, gdb::unique_xmalloc_ptr debug_filename; static const char artificial[] = ""; file_and_directory fnd = find_file_and_directory (comp_unit_die, cu); - if (strcmp (fnd.name, artificial) == 0) + if (strcmp (fnd.get_name (), artificial) == 0) { debug_filename.reset (concat (artificial, "@", sect_offset_str (per_cu->sect_off), (char *) NULL)); - fnd.name = debug_filename.get (); + fnd.set_name (debug_filename.get ()); } - pst = create_partial_symtab (per_cu, per_objfile, fnd.name); + pst = create_partial_symtab (per_cu, per_objfile, fnd.get_name ()); /* This must be done before calling dwarf2_build_include_psymtabs. */ pst->dirname = dwarf2_string_attr (comp_unit_die, DW_AT_comp_dir, cu); @@ -10493,25 +10478,16 @@ producer_is_gcc_lt_4_3 (struct dwarf2_cu *cu) static file_and_directory find_file_and_directory (struct die_info *die, struct dwarf2_cu *cu) { - file_and_directory res; - /* Find the filename. Do not use dwarf2_name here, since the filename is not a source language identifier. */ - res.name = dwarf2_string_attr (die, DW_AT_name, cu); - res.comp_dir = dwarf2_string_attr (die, DW_AT_comp_dir, cu); - - if (res.comp_dir == NULL - && producer_is_gcc_lt_4_3 (cu) && res.name != NULL - && IS_ABSOLUTE_PATH (res.name)) - { - std::string comp_dir_storage = ldirname (res.name); - if (!comp_dir_storage.empty ()) - res.comp_dir - = cu->per_objfile->objfile->intern (comp_dir_storage.c_str ()); - } + file_and_directory res (dwarf2_string_attr (die, DW_AT_name, cu), + dwarf2_string_attr (die, DW_AT_comp_dir, cu)); - if (res.name == NULL) - res.name = ""; + if (res.get_comp_dir () == nullptr + && producer_is_gcc_lt_4_3 (cu) + && res.get_name () != nullptr + && IS_ABSOLUTE_PATH (res.get_name ())) + res.set_comp_dir (ldirname (res.get_name ())); return res; } @@ -10643,7 +10619,7 @@ read_file_scope (struct die_info *die, struct dwarf2_cu *cu) file_and_directory fnd = find_file_and_directory (die, cu); - cu->start_symtab (fnd.name, fnd.comp_dir, lowpc); + cu->start_symtab (fnd.get_name (), fnd.intern_comp_dir (objfile), lowpc); gdb_assert (per_objfile->sym_cu == nullptr); scoped_restore restore_sym_cu @@ -20752,7 +20728,7 @@ compute_include_file_name (const struct line_header *lh, const file_entry &fe, gdb::unique_xmalloc_ptr hold_compare; if (!IS_ABSOLUTE_PATH (include_name) - && (dir_name != NULL || cu_info.comp_dir != NULL)) + && (dir_name != nullptr || cu_info.get_comp_dir () != nullptr)) { /* Avoid creating a duplicate name for CU_INFO. We do this by comparing INCLUDE_NAME and CU_INFO. @@ -20782,19 +20758,20 @@ compute_include_file_name (const struct line_header *lh, const file_entry &fe, include_name = name_holder->get (); include_name_to_compare = include_name; } - if (!IS_ABSOLUTE_PATH (include_name) && cu_info.comp_dir != nullptr) + if (!IS_ABSOLUTE_PATH (include_name) + && cu_info.get_comp_dir () != nullptr) { - hold_compare.reset (concat (cu_info.comp_dir, SLASH_STRING, + hold_compare.reset (concat (cu_info.get_comp_dir (), SLASH_STRING, include_name, (char *) NULL)); include_name_to_compare = hold_compare.get (); } } gdb::unique_xmalloc_ptr copied_name; - const char *cu_filename = cu_info.name; - if (!IS_ABSOLUTE_PATH (cu_filename) && cu_info.comp_dir != nullptr) + const char *cu_filename = cu_info.get_name (); + if (!IS_ABSOLUTE_PATH (cu_filename) && cu_info.get_comp_dir () != nullptr) { - copied_name.reset (concat (cu_info.comp_dir, SLASH_STRING, + copied_name.reset (concat (cu_info.get_comp_dir (), SLASH_STRING, cu_filename, (char *) NULL)); cu_filename = copied_name.get (); } -- 2.30.2