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_nextcu.c b/libdw/dwarf_nextcu.c
new file mode 100644
index 0000000..fa9b0af
--- /dev/null
+++ b/libdw/dwarf_nextcu.c
@@ -0,0 +1,186 @@
+/* Advance to next CU header.
+ Copyright (C) 2002-2010 Red Hat, Inc.
+ This file is part of elfutils.
+ Written by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+ 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>
+
+
+int
+dwarf_next_unit (Dwarf *dwarf, Dwarf_Off off, Dwarf_Off *next_off,
+ size_t *header_sizep, Dwarf_Half *versionp,
+ Dwarf_Off *abbrev_offsetp, uint8_t *address_sizep,
+ uint8_t *offset_sizep, uint64_t *type_signaturep,
+ Dwarf_Off *type_offsetp)
+{
+ const bool debug_types = type_signaturep != NULL;
+ const size_t sec_idx = debug_types ? IDX_debug_types : IDX_debug_info;
+
+ /* Maybe there has been an error before. */
+ if (dwarf == NULL)
+ return -1;
+
+ /* If we reached the end before don't do anything. */
+ if (off == (Dwarf_Off) -1l
+ || unlikely (dwarf->sectiondata[sec_idx] == NULL)
+ /* Make sure there is enough space in the .debug_info section
+ for at least the initial word. We cannot test the rest since
+ we don't know yet whether this is a 64-bit object or not. */
+ || unlikely (off + 4 >= dwarf->sectiondata[sec_idx]->d_size))
+ {
+ *next_off = (Dwarf_Off) -1l;
+ return 1;
+ }
+
+ /* This points into the .debug_info section to the beginning of the
+ CU entry. */
+ const unsigned char *data = dwarf->sectiondata[sec_idx]->d_buf;
+ const unsigned char *bytes = data + off;
+
+ /* The format of the CU header is described in dwarf2p1 7.5.1:
+
+ 1. A 4-byte or 12-byte unsigned integer representing the length
+ of the .debug_info contribution for that compilation unit, not
+ including the length field itself. In the 32-bit DWARF format,
+ this is a 4-byte unsigned integer (which must be less than
+ 0xfffffff0); in the 64-bit DWARF format, this consists of the
+ 4-byte value 0xffffffff followed by an 8-byte unsigned integer
+ that gives the actual length (see Section 7.2.2).
+
+ 2. A 2-byte unsigned integer representing the version of the
+ DWARF information for that compilation unit. For DWARF Version
+ 2.1, the value in this field is 2.
+
+ 3. A 4-byte or 8-byte unsigned offset into the .debug_abbrev
+ section. This offset associates the compilation unit with a
+ particular set of debugging information entry abbreviations. In
+ the 32-bit DWARF format, this is a 4-byte unsigned length; in
+ the 64-bit DWARF format, this is an 8-byte unsigned length (see
+ Section 7.4).
+
+ 4. A 1-byte unsigned integer representing the size in bytes of
+ an address on the target architecture. If the system uses
+ segmented addressing, this value represents the size of the
+ offset portion of an address. */
+ uint64_t length = read_4ubyte_unaligned_inc (dwarf, bytes);
+ size_t offset_size = 4;
+ /* Lengths of 0xfffffff0 - 0xffffffff are escape codes. Oxffffffff is
+ used to indicate that 64-bit dwarf information is being used, the
+ other values are currently reserved. */
+ if (length == DWARF3_LENGTH_64_BIT)
+ offset_size = 8;
+ else if (unlikely (length >= DWARF3_LENGTH_MIN_ESCAPE_CODE
+ && length <= DWARF3_LENGTH_MAX_ESCAPE_CODE))
+ {
+ invalid:
+ __libdw_seterrno (DWARF_E_INVALID_DWARF);
+ return -1;
+ }
+
+ /* Now we know how large the header is. */
+ if (unlikely (DIE_OFFSET_FROM_CU_OFFSET (off, offset_size, debug_types)
+ >= dwarf->sectiondata[sec_idx]->d_size))
+ {
+ *next_off = -1;
+ return 1;
+ }
+
+ if (length == DWARF3_LENGTH_64_BIT)
+ /* This is a 64-bit DWARF format. */
+ length = read_8ubyte_unaligned_inc (dwarf, bytes);
+
+ /* Read the version stamp. Always a 16-bit value. */
+ uint_fast16_t version = read_2ubyte_unaligned_inc (dwarf, bytes);
+
+ /* Get offset in .debug_abbrev. Note that the size of the entry
+ depends on whether this is a 32-bit or 64-bit DWARF definition. */
+ uint64_t abbrev_offset;
+ if (__libdw_read_offset_inc (dwarf, sec_idx, &bytes, offset_size,
+ &abbrev_offset, IDX_debug_abbrev, 0))
+ return -1;
+
+ /* The address size. Always an 8-bit value. */
+ uint8_t address_size = *bytes++;
+
+ if (debug_types)
+ {
+ uint64_t type_sig8 = read_8ubyte_unaligned_inc (dwarf, bytes);
+
+ Dwarf_Off type_offset;
+ if (__libdw_read_offset_inc (dwarf, sec_idx, &bytes, offset_size,
+ &type_offset, sec_idx, 0))
+ return -1;
+
+ /* Validate that the TYPE_OFFSET points past the header. */
+ if (unlikely (type_offset < (size_t) (bytes - (data + off))))
+ goto invalid;
+
+ *type_signaturep = type_sig8;
+ if (type_offsetp != NULL)
+ *type_offsetp = type_offset;
+ }
+
+ /* Store the header length. */
+ if (header_sizep != NULL)
+ *header_sizep = bytes - (data + off);
+
+ if (versionp != NULL)
+ *versionp = version;
+
+ if (abbrev_offsetp != NULL)
+ *abbrev_offsetp = abbrev_offset;
+
+ if (address_sizep != NULL)
+ *address_sizep = address_size;
+
+ /* Store the offset size. */
+ if (offset_sizep != NULL)
+ *offset_sizep = offset_size;
+
+ /* See definition of DIE_OFFSET_FROM_CU_OFFSET macro
+ for an explanation of the trick in this expression. */
+ *next_off = off + 2 * offset_size - 4 + length;
+
+ return 0;
+}
+INTDEF(dwarf_next_unit)
+
+int
+dwarf_nextcu (Dwarf *dwarf, Dwarf_Off off, Dwarf_Off *next_off,
+ size_t *header_sizep, Dwarf_Off *abbrev_offsetp,
+ uint8_t *address_sizep, uint8_t *offset_sizep)
+{
+ return INTUSE(dwarf_next_unit) (dwarf, off, next_off, header_sizep, NULL,
+ abbrev_offsetp, address_sizep, offset_sizep,
+ NULL, NULL);
+}
+INTDEF(dwarf_nextcu)