diff options
Diffstat (limited to 'libdw/libdw_findcu.c')
| -rw-r--r-- | libdw/libdw_findcu.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/libdw/libdw_findcu.c b/libdw/libdw_findcu.c new file mode 100644 index 00000000..d8da2e38 --- /dev/null +++ b/libdw/libdw_findcu.c @@ -0,0 +1,172 @@ +/* Find CU for given offset. + Copyright (C) 2003-2010, 2014 Red Hat, Inc. + This file is part of elfutils. + Written by Ulrich Drepper <drepper@redhat.com>, 2003. + + 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 <assert.h> +#include <search.h> +#include "libdwP.h" + +static int +findcu_cb (const void *arg1, const void *arg2) +{ + struct Dwarf_CU *cu1 = (struct Dwarf_CU *) arg1; + struct Dwarf_CU *cu2 = (struct Dwarf_CU *) arg2; + + /* Find out which of the two arguments is the search value. It has + end offset 0. */ + if (cu1->end == 0) + { + if (cu1->start < cu2->start) + return -1; + if (cu1->start >= cu2->end) + return 1; + } + else + { + if (cu2->start < cu1->start) + return 1; + if (cu2->start >= cu1->end) + return -1; + } + + return 0; +} + +struct Dwarf_CU * +internal_function +__libdw_intern_next_unit (dbg, debug_types) + Dwarf *dbg; + bool debug_types; +{ + Dwarf_Off *const offsetp + = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset; + void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree; + + Dwarf_Off oldoff = *offsetp; + uint16_t version; + uint8_t address_size; + uint8_t offset_size; + Dwarf_Off abbrev_offset; + uint64_t type_sig8 = 0; + Dwarf_Off type_offset = 0; + + if (INTUSE(dwarf_next_unit) (dbg, oldoff, offsetp, NULL, + &version, &abbrev_offset, + &address_size, &offset_size, + debug_types ? &type_sig8 : NULL, + debug_types ? &type_offset : NULL) != 0) + /* No more entries. */ + return NULL; + + /* We only know how to handle the DWARF version 2 through 4 formats. */ + if (unlikely (version < 2) || unlikely (version > 4)) + { + __libdw_seterrno (DWARF_E_INVALID_DWARF); + return NULL; + } + + /* Invalid or truncated debug section data? */ + Elf_Data *data = dbg->sectiondata[debug_types + ? IDX_debug_types : IDX_debug_info]; + if (unlikely (*offsetp > data->d_size)) + *offsetp = data->d_size; + + /* Create an entry for this CU. */ + struct Dwarf_CU *newp = libdw_typed_alloc (dbg, struct Dwarf_CU); + + newp->dbg = dbg; + newp->start = oldoff; + newp->end = *offsetp; + newp->address_size = address_size; + newp->offset_size = offset_size; + newp->version = version; + newp->type_sig8 = type_sig8; + newp->type_offset = type_offset; + Dwarf_Abbrev_Hash_init (&newp->abbrev_hash, 41); + newp->orig_abbrev_offset = newp->last_abbrev_offset = abbrev_offset; + newp->lines = NULL; + newp->locs = NULL; + + if (debug_types) + Dwarf_Sig8_Hash_insert (&dbg->sig8_hash, type_sig8, newp); + + newp->startp = data->d_buf + newp->start; + newp->endp = data->d_buf + newp->end; + + /* Add the new entry to the search tree. */ + if (tsearch (newp, tree, findcu_cb) == NULL) + { + /* Something went wrong. Undo the operation. */ + *offsetp = oldoff; + __libdw_seterrno (DWARF_E_NOMEM); + return NULL; + } + + return newp; +} + +struct Dwarf_CU * +__libdw_findcu (dbg, start, debug_types) + Dwarf *dbg; + Dwarf_Off start; + bool debug_types; +{ + void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree; + Dwarf_Off *next_offset + = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset; + + /* Maybe we already know that CU. */ + struct Dwarf_CU fake = { .start = start, .end = 0 }; + struct Dwarf_CU **found = tfind (&fake, tree, findcu_cb); + if (found != NULL) + return *found; + + if (start < *next_offset) + { + __libdw_seterrno (DWARF_E_INVALID_DWARF); + return NULL; + } + + /* No. Then read more CUs. */ + while (1) + { + struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, debug_types); + if (newp == NULL) + return NULL; + + /* Is this the one we are looking for? */ + if (start < *next_offset) + // XXX Match exact offset. + return newp; + } + /* NOTREACHED */ +} |