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Diffstat (limited to 'src/libdw/dwarf_getabbrev.c')
| -rw-r--r-- | src/libdw/dwarf_getabbrev.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/src/libdw/dwarf_getabbrev.c b/src/libdw/dwarf_getabbrev.c new file mode 100644 index 00000000..07bf6dfc --- /dev/null +++ b/src/libdw/dwarf_getabbrev.c @@ -0,0 +1,170 @@ +/* Get abbreviation at given offset. + Copyright (C) 2003, 2004, 2005, 2006 Red Hat, Inc. + This file is part of Red Hat elfutils. + Written by Ulrich Drepper <drepper@redhat.com>, 2003. + + Red Hat elfutils 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; version 2 of the License. + + Red Hat 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 a copy of the GNU General Public License along + with Red Hat elfutils; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. + + In addition, as a special exception, Red Hat, Inc. gives You the + additional right to link the code of Red Hat elfutils with code licensed + under any Open Source Initiative certified open source license + (http://www.opensource.org/licenses/index.php) which requires the + distribution of source code with any binary distribution and to + distribute linked combinations of the two. Non-GPL Code permitted under + this exception must only link to the code of Red Hat elfutils through + those well defined interfaces identified in the file named EXCEPTION + found in the source code files (the "Approved Interfaces"). The files + of Non-GPL Code may instantiate templates or use macros or inline + functions from the Approved Interfaces without causing the resulting + work to be covered by the GNU General Public License. Only Red Hat, + Inc. may make changes or additions to the list of Approved Interfaces. + Red Hat's grant of this exception is conditioned upon your not adding + any new exceptions. If you wish to add a new Approved Interface or + exception, please contact Red Hat. You must obey the GNU General Public + License in all respects for all of the Red Hat elfutils code and other + code used in conjunction with Red Hat elfutils except the Non-GPL Code + covered by this exception. If you modify this file, you may extend this + exception to your version of the file, but you are not obligated to do + so. If you do not wish to provide this exception without modification, + you must delete this exception statement from your version and license + this file solely under the GPL without exception. + + Red Hat elfutils is an included package of the Open Invention Network. + An included package of the Open Invention Network is a package for which + Open Invention Network licensees cross-license their patents. No patent + license is granted, either expressly or impliedly, by designation as an + included package. Should you wish to participate in the Open Invention + Network licensing program, please visit www.openinventionnetwork.com + <http://www.openinventionnetwork.com>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <assert.h> +#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; + + assert (abb->offset == offset); + + /* 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); +} |