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_formref_die.c b/libdw/dwarf_formref_die.c
new file mode 100644
index 0000000..704816f
--- /dev/null
+++ b/libdw/dwarf_formref_die.c
@@ -0,0 +1,119 @@
+/* Look up the DIE in a reference-form attribute.
+ Copyright (C) 2005-2010, 2018 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 <string.h>
+#include "libdwP.h"
+#include <dwarf.h>
+
+
+Dwarf_Die *
+dwarf_formref_die (Dwarf_Attribute *attr, Dwarf_Die *result)
+{
+ if (attr == NULL)
+ return NULL;
+
+ struct Dwarf_CU *cu = attr->cu;
+
+ Dwarf_Off offset;
+ if (attr->form == DW_FORM_ref_addr || attr->form == DW_FORM_GNU_ref_alt)
+ {
+ /* This has an absolute offset. */
+
+ uint8_t ref_size = (cu->version == 2 && attr->form == DW_FORM_ref_addr
+ ? cu->address_size
+ : cu->offset_size);
+
+ Dwarf *dbg_ret = (attr->form == DW_FORM_GNU_ref_alt
+ ? INTUSE(dwarf_getalt) (cu->dbg) : cu->dbg);
+
+ if (dbg_ret == NULL)
+ {
+ __libdw_seterrno (DWARF_E_NO_ALT_DEBUGLINK);
+ return NULL;
+ }
+
+ if (__libdw_read_offset (cu->dbg, dbg_ret, IDX_debug_info, attr->valp,
+ ref_size, &offset, IDX_debug_info, 0))
+ return NULL;
+
+ return INTUSE(dwarf_offdie) (dbg_ret, offset, result);
+ }
+
+ const unsigned char *datap;
+ size_t size;
+ if (attr->form == DW_FORM_ref_sig8)
+ {
+ /* This doesn't have an offset, but instead a value we
+ have to match in the .debug_types type unit headers. */
+
+ uint64_t sig = read_8ubyte_unaligned (cu->dbg, attr->valp);
+ cu = Dwarf_Sig8_Hash_find (&cu->dbg->sig8_hash, sig, NULL);
+ if (cu == NULL)
+ /* Not seen before. We have to scan through the type units. */
+ do
+ {
+ cu = __libdw_intern_next_unit (attr->cu->dbg, true);
+ if (cu == NULL)
+ {
+ __libdw_seterrno (INTUSE(dwarf_errno) ()
+ ?: DWARF_E_INVALID_REFERENCE);
+ return NULL;
+ }
+ }
+ while (cu->type_sig8 != sig);
+
+ datap = cu->dbg->sectiondata[IDX_debug_types]->d_buf;
+ size = cu->dbg->sectiondata[IDX_debug_types]->d_size;
+ offset = cu->start + cu->type_offset;
+ }
+ else
+ {
+ /* Other forms produce an offset from the CU. */
+ if (unlikely (__libdw_formref (attr, &offset) != 0))
+ return NULL;
+
+ datap = cu->startp;
+ size = cu->endp - cu->startp;
+ }
+
+ if (unlikely (offset >= size))
+ {
+ __libdw_seterrno (DWARF_E_INVALID_DWARF);
+ return NULL;
+ }
+
+ memset (result, '\0', sizeof (Dwarf_Die));
+ result->addr = (char *) datap + offset;
+ result->cu = cu;
+ return result;
+}
+INTDEF (dwarf_formref_die)