/* Enumerate the PC ranges covered by a DIE. Copyright (C) 2005, 2007, 2009 Red Hat, Inc. This file is part of Red Hat elfutils. 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 . */ #ifdef HAVE_CONFIG_H # include #endif #include "libdwP.h" #include #include /* Read up begin/end pair and increment read pointer. - If it's normal range record, set up `*beginp' and `*endp' and return 0. - If it's base address selection record, set up `*basep' and return 1. - If it's end of rangelist, don't set anything and return 2 - If an error occurs, don't set anything and return -1. */ internal_function int __libdw_read_begin_end_pair_inc (Dwarf *dbg, int sec_index, unsigned char **addrp, int width, Dwarf_Addr *beginp, Dwarf_Addr *endp, Dwarf_Addr *basep) { Dwarf_Addr escape = (width == 8 ? (Elf64_Addr) -1 : (Elf64_Addr) (Elf32_Addr) -1); Dwarf_Addr begin; Dwarf_Addr end; unsigned char *addr = *addrp; bool begin_relocated = READ_AND_RELOCATE (__libdw_relocate_address, begin); bool end_relocated = READ_AND_RELOCATE (__libdw_relocate_address, end); *addrp = addr; /* Unrelocated escape for begin means base address selection. */ if (begin == escape && !begin_relocated) { if (unlikely (end == escape)) { __libdw_seterrno (DWARF_E_INVALID_DWARF); return -1; } if (basep != NULL) *basep = end; return 1; } /* Unrelocated pair of zeroes means end of range list. */ if (begin == 0 && end == 0 && !begin_relocated && !end_relocated) return 2; /* Don't check for begin_relocated == end_relocated. Serve the data to the client even though it may be buggy. */ *beginp = begin; *endp = end; return 0; } ptrdiff_t dwarf_ranges (Dwarf_Die *die, ptrdiff_t offset, Dwarf_Addr *basep, Dwarf_Addr *startp, Dwarf_Addr *endp) { if (die == NULL) return -1; if (offset == 0 /* Usually there is a single contiguous range. */ && INTUSE(dwarf_highpc) (die, endp) == 0 && INTUSE(dwarf_lowpc) (die, startp) == 0) /* A offset into .debug_ranges will never be 1, it must be at least a multiple of 4. So we can return 1 as a special case value to mark there are no ranges to look for on the next call. */ return 1; if (offset == 1) return 0; /* We have to look for a noncontiguous range. */ const Elf_Data *d = die->cu->dbg->sectiondata[IDX_debug_ranges]; if (d == NULL && offset != 0) { __libdw_seterrno (DWARF_E_NO_DEBUG_RANGES); return -1; } unsigned char *readp; unsigned char *readendp; if (offset == 0) { Dwarf_Attribute attr_mem; Dwarf_Attribute *attr = INTUSE(dwarf_attr) (die, DW_AT_ranges, &attr_mem); if (attr == NULL) /* No PC attributes in this DIE at all, so an empty range list. */ return 0; Dwarf_Word start_offset; if ((readp = __libdw_formptr (attr, IDX_debug_ranges, DWARF_E_NO_DEBUG_RANGES, &readendp, &start_offset)) == NULL) return -1; offset = start_offset; assert ((Dwarf_Word) offset == start_offset); /* Fetch the CU's base address. */ Dwarf_Die cudie = CUDIE (attr->cu); /* Find the base address of the compilation unit. It will normally be specified by DW_AT_low_pc. In DWARF-3 draft 4, the base address could be overridden by DW_AT_entry_pc. It's been removed, but GCC emits DW_AT_entry_pc and not DW_AT_lowpc for compilation units with discontinuous ranges. */ if (unlikely (INTUSE(dwarf_lowpc) (&cudie, basep) != 0) && INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (&cudie, DW_AT_entry_pc, &attr_mem), basep) != 0) { if (INTUSE(dwarf_errno) () == 0) { invalid: __libdw_seterrno (DWARF_E_INVALID_DWARF); } return -1; } } else { if (__libdw_offset_in_section (die->cu->dbg, IDX_debug_ranges, offset, 1)) return -1l; readp = d->d_buf + offset; readendp = d->d_buf + d->d_size; } next: if (readendp - readp < die->cu->address_size * 2) goto invalid; Dwarf_Addr begin; Dwarf_Addr end; switch (__libdw_read_begin_end_pair_inc (die->cu->dbg, IDX_debug_ranges, &readp, die->cu->address_size, &begin, &end, basep)) { case 0: break; case 1: goto next; case 2: return 0; default: return -1l; } /* We have an address range entry. */ *startp = *basep + begin; *endp = *basep + end; return readp - (unsigned char *) d->d_buf; } INTDEF (dwarf_ranges)