| /* Get abbreviation at given offset. |
| Copyright (C) 2003, 2004, 2005, 2006, 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 <dwarf.h> |
| #include "libdwP.h" |
| |
| |
| Dwarf_Abbrev * |
| internal_function |
| __libdw_getabbrev (dbg, cu, offset, lengthp, result) |
| Dwarf *dbg; |
| struct Dwarf_CU *cu; |
| Dwarf_Off offset; |
| size_t *lengthp; |
| Dwarf_Abbrev *result; |
| { |
| /* Don't fail if there is not .debug_abbrev section. */ |
| if (dbg->sectiondata[IDX_debug_abbrev] == NULL) |
| return NULL; |
| |
| if (offset >= dbg->sectiondata[IDX_debug_abbrev]->d_size) |
| { |
| __libdw_seterrno (DWARF_E_INVALID_OFFSET); |
| return NULL; |
| } |
| |
| const unsigned char *abbrevp |
| = (unsigned char *) dbg->sectiondata[IDX_debug_abbrev]->d_buf + offset; |
| |
| if (*abbrevp == '\0') |
| /* We are past the last entry. */ |
| return DWARF_END_ABBREV; |
| |
| /* 7.5.3 Abbreviations Tables |
| |
| [...] Each declaration begins with an unsigned LEB128 number |
| representing the abbreviation code itself. [...] The |
| abbreviation code is followed by another unsigned LEB128 |
| number that encodes the entry's tag. [...] |
| |
| [...] Following the tag encoding is a 1-byte value that |
| determines whether a debugging information entry using this |
| abbreviation has child entries or not. [...] |
| |
| [...] Finally, the child encoding is followed by a series of |
| attribute specifications. Each attribute specification |
| consists of two parts. The first part is an unsigned LEB128 |
| number representing the attribute's name. The second part is |
| an unsigned LEB128 number representing the attribute's form. */ |
| const unsigned char *start_abbrevp = abbrevp; |
| unsigned int code; |
| get_uleb128 (code, abbrevp); |
| |
| /* Check whether this code is already in the hash table. */ |
| bool foundit = false; |
| Dwarf_Abbrev *abb = NULL; |
| if (cu == NULL |
| || (abb = Dwarf_Abbrev_Hash_find (&cu->abbrev_hash, code, NULL)) == NULL) |
| { |
| if (result == NULL) |
| abb = libdw_typed_alloc (dbg, Dwarf_Abbrev); |
| else |
| abb = result; |
| } |
| else |
| { |
| foundit = true; |
| |
| if (unlikely (abb->offset != offset)) |
| { |
| /* A duplicate abbrev code at a different offset, |
| that should never happen. */ |
| __libdw_seterrno (DWARF_E_INVALID_DWARF); |
| return NULL; |
| } |
| |
| /* If the caller doesn't need the length we are done. */ |
| if (lengthp == NULL) |
| goto out; |
| } |
| |
| /* If there is already a value in the hash table we are going to |
| overwrite its content. This must not be a problem, since the |
| content better be the same. */ |
| abb->code = code; |
| get_uleb128 (abb->tag, abbrevp); |
| abb->has_children = *abbrevp++ == DW_CHILDREN_yes; |
| abb->attrp = (unsigned char *) abbrevp; |
| abb->offset = offset; |
| |
| /* Skip over all the attributes and count them while doing so. */ |
| abb->attrcnt = 0; |
| unsigned int attrname; |
| unsigned int attrform; |
| do |
| { |
| get_uleb128 (attrname, abbrevp); |
| get_uleb128 (attrform, abbrevp); |
| } |
| while (attrname != 0 && attrform != 0 && ++abb->attrcnt); |
| |
| /* Return the length to the caller if she asked for it. */ |
| if (lengthp != NULL) |
| *lengthp = abbrevp - start_abbrevp; |
| |
| /* Add the entry to the hash table. */ |
| if (cu != NULL && ! foundit) |
| (void) Dwarf_Abbrev_Hash_insert (&cu->abbrev_hash, abb->code, abb); |
| |
| out: |
| return abb; |
| } |
| |
| |
| Dwarf_Abbrev * |
| dwarf_getabbrev (die, offset, lengthp) |
| Dwarf_Die *die; |
| Dwarf_Off offset; |
| size_t *lengthp; |
| { |
| return __libdw_getabbrev (die->cu->dbg, die->cu, |
| die->cu->orig_abbrev_offset + offset, lengthp, |
| NULL); |
| } |