diff options
Diffstat (limited to 'libdw/dwarf_getattrs.c')
| -rw-r--r-- | libdw/dwarf_getattrs.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/libdw/dwarf_getattrs.c b/libdw/dwarf_getattrs.c new file mode 100644 index 00000000..0da8b5ba --- /dev/null +++ b/libdw/dwarf_getattrs.c @@ -0,0 +1,120 @@ +/* Get attributes of the DIE. + Copyright (C) 2004, 2005, 2008, 2009, 2014 Red Hat, Inc. + This file is part of elfutils. + Written by Ulrich Drepper <drepper@redhat.com>, 2004. + + 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" + + +ptrdiff_t +dwarf_getattrs (Dwarf_Die *die, int (*callback) (Dwarf_Attribute *, void *), + void *arg, ptrdiff_t offset) +{ + if (die == NULL) + return -1l; + + if (unlikely (offset == 1)) + return 1; + + const unsigned char *die_addr; + + /* Find the abbreviation entry. */ + Dwarf_Abbrev *abbrevp = __libdw_dieabbrev (die, &die_addr); + + if (unlikely (abbrevp == DWARF_END_ABBREV)) + { + invalid_dwarf: + __libdw_seterrno (DWARF_E_INVALID_DWARF); + return -1l; + } + + /* This is where the attributes start. */ + const unsigned char *attrp = abbrevp->attrp; + const unsigned char *const offset_attrp = abbrevp->attrp + offset; + + /* Go over the list of attributes. */ + Dwarf *dbg = die->cu->dbg; + const unsigned char *endp; + endp = ((const unsigned char *) dbg->sectiondata[IDX_debug_abbrev]->d_buf + + dbg->sectiondata[IDX_debug_abbrev]->d_size); + while (1) + { + /* Are we still in bounds? */ + if (unlikely (attrp >= endp)) + goto invalid_dwarf; + + /* Get attribute name and form. */ + Dwarf_Attribute attr; + const unsigned char *remembered_attrp = attrp; + + get_uleb128 (attr.code, attrp, endp); + if (unlikely (attrp >= endp)) + goto invalid_dwarf; + get_uleb128 (attr.form, attrp, endp); + + /* We can stop if we found the attribute with value zero. */ + if (attr.code == 0 && attr.form == 0) + /* Do not return 0 here - there would be no way to + distinguish this value from the attribute at offset 0. + Instead we return +1 which would never be a valid + offset of an attribute. */ + return 1l; + + /* If we are not to OFFSET_ATTRP yet, we just have to skip + the values of the intervening attributes. */ + if (remembered_attrp >= offset_attrp) + { + /* Fill in the rest. */ + attr.valp = (unsigned char *) die_addr; + attr.cu = die->cu; + + /* Now call the callback function. */ + if (callback (&attr, arg) != DWARF_CB_OK) + /* Return the offset of the start of the attribute, so that + dwarf_getattrs() can be restarted from this point if the + caller so desires. */ + return remembered_attrp - abbrevp->attrp; + } + + /* Skip over the rest of this attribute (if there is any). */ + if (attr.form != 0) + { + size_t len = __libdw_form_val_len (die->cu, attr.form, die_addr); + if (unlikely (len == (size_t) -1l)) + /* Something wrong with the file. */ + return -1l; + + // __libdw_form_val_len will have done a bounds check. + die_addr += len; + } + } + /* NOTREACHED */ +} |