| /* Find the split (or skeleton) unit for a given unit. |
| Copyright (C) 2018 Red Hat, Inc. |
| This file is part of elfutils. |
| |
| This file is free software; you can redistribute it and/or modify |
| it under the terms of either |
| |
| * the GNU Lesser General Public License as published by the Free |
| Software Foundation; either version 3 of the License, or (at |
| your option) any later version |
| |
| or |
| |
| * the GNU General Public License as published by the Free |
| Software Foundation; either version 2 of the License, or (at |
| your option) any later version |
| |
| or both in parallel, as here. |
| |
| elfutils 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 copies of the GNU General Public License and |
| the GNU Lesser General Public License along with this program. If |
| not, see <http://www.gnu.org/licenses/>. */ |
| |
| #ifdef HAVE_CONFIG_H |
| # include <config.h> |
| #endif |
| |
| #include "libdwP.h" |
| #include "libelfP.h" |
| |
| #include <limits.h> |
| #include <search.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| |
| void |
| try_split_file (Dwarf_CU *cu, const char *dwo_path) |
| { |
| int split_fd = open (dwo_path, O_RDONLY); |
| if (split_fd != -1) |
| { |
| Dwarf *split_dwarf = dwarf_begin (split_fd, DWARF_C_READ); |
| if (split_dwarf != NULL) |
| { |
| Dwarf_CU *split = NULL; |
| while (dwarf_get_units (split_dwarf, split, &split, |
| NULL, NULL, NULL, NULL) == 0) |
| { |
| if (split->unit_type == DW_UT_split_compile |
| && cu->unit_id8 == split->unit_id8) |
| { |
| if (tsearch (split->dbg, &cu->dbg->split_tree, |
| __libdw_finddbg_cb) == NULL) |
| { |
| /* Something went wrong. Don't link. */ |
| __libdw_seterrno (DWARF_E_NOMEM); |
| break; |
| } |
| |
| /* Link skeleton and split compile units. */ |
| __libdw_link_skel_split (cu, split); |
| |
| /* We have everything we need from this ELF |
| file. And we are going to close the fd to |
| not run out of file descriptors. */ |
| elf_cntl (split_dwarf->elf, ELF_C_FDDONE); |
| break; |
| } |
| } |
| if (cu->split == (Dwarf_CU *) -1) |
| dwarf_end (split_dwarf); |
| } |
| /* Always close, because we don't want to run out of file |
| descriptors. See also the elf_fcntl ELF_C_FDDONE call |
| above. */ |
| close (split_fd); |
| } |
| } |
| |
| Dwarf_CU * |
| internal_function |
| __libdw_find_split_unit (Dwarf_CU *cu) |
| { |
| /* Only try once. */ |
| if (cu->split != (Dwarf_CU *) -1) |
| return cu->split; |
| |
| /* We need a skeleton unit with a comp_dir and [GNU_]dwo_name attributes. |
| The split unit will be the first in the dwo file and should have the |
| same id as the skeleton. */ |
| if (cu->unit_type == DW_UT_skeleton) |
| { |
| Dwarf_Die cudie = CUDIE (cu); |
| Dwarf_Attribute dwo_name; |
| /* It is fine if dwo_dir doesn't exists, but then dwo_name needs |
| to be an absolute path. */ |
| if (dwarf_attr (&cudie, DW_AT_dwo_name, &dwo_name) != NULL |
| || dwarf_attr (&cudie, DW_AT_GNU_dwo_name, &dwo_name) != NULL) |
| { |
| /* First try the dwo file name in the same directory |
| as we found the skeleton file. */ |
| const char *dwo_file = dwarf_formstring (&dwo_name); |
| const char *debugdir = cu->dbg->debugdir; |
| char *dwo_path = __libdw_filepath (debugdir, NULL, dwo_file); |
| if (dwo_path != NULL) |
| { |
| try_split_file (cu, dwo_path); |
| free (dwo_path); |
| } |
| |
| if (cu->split == (Dwarf_CU *) -1) |
| { |
| /* Try compdir plus dwo_name. */ |
| Dwarf_Attribute compdir; |
| dwarf_attr (&cudie, DW_AT_comp_dir, &compdir); |
| const char *dwo_dir = dwarf_formstring (&compdir); |
| if (dwo_dir != NULL) |
| { |
| dwo_path = __libdw_filepath (debugdir, dwo_dir, dwo_file); |
| if (dwo_path != NULL) |
| { |
| try_split_file (cu, dwo_path); |
| free (dwo_path); |
| } |
| } |
| } |
| /* XXX If still not found we could try stripping dirs from the |
| comp_dir and adding them from the comp_dir, assuming |
| someone moved a whole build tree around. */ |
| } |
| } |
| |
| /* If we found nothing, make sure we don't try again. */ |
| if (cu->split == (Dwarf_CU *) -1) |
| cu->split = NULL; |
| |
| return cu->split; |
| } |