Squashed 'third_party/elfutils/' content from commit 555e15e
Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libdw/dwarf_ranges.c b/libdw/dwarf_ranges.c
new file mode 100644
index 0000000..4b6853d
--- /dev/null
+++ b/libdw/dwarf_ranges.c
@@ -0,0 +1,193 @@
+/* Enumerate the PC ranges covered by a DIE.
+ Copyright (C) 2005, 2007, 2009 Red Hat, Inc.
+ This file is part of elfutils.
+
+ 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"
+#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)
+ *basep = (Dwarf_Addr) -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. Check that we have a base. */
+ if (*basep == (Dwarf_Addr) -1)
+ {
+ if (INTUSE(dwarf_errno) () == 0)
+ {
+ invalid:
+ __libdw_seterrno (DWARF_E_INVALID_DWARF);
+ }
+ return -1;
+ }
+
+ *startp = *basep + begin;
+ *endp = *basep + end;
+ return readp - (unsigned char *) d->d_buf;
+}
+INTDEF (dwarf_ranges)