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Diffstat (limited to 'src/libdw/dwarf_ranges.c')
| -rw-r--r-- | src/libdw/dwarf_ranges.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/src/libdw/dwarf_ranges.c b/src/libdw/dwarf_ranges.c new file mode 100644 index 00000000..50fb6ba2 --- /dev/null +++ b/src/libdw/dwarf_ranges.c @@ -0,0 +1,211 @@ +/* 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 + <http://www.openinventionnetwork.com>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include "libdwP.h" +#include <dwarf.h> +#include <assert.h> + +/* 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) |