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_getabbrev.c b/libdw/dwarf_getabbrev.c
new file mode 100644
index 0000000..a3a68b3
--- /dev/null
+++ b/libdw/dwarf_getabbrev.c
@@ -0,0 +1,157 @@
+/* Get abbreviation at given offset.
+ Copyright (C) 2003, 2004, 2005, 2006, 2014, 2017 Red Hat, Inc.
+ This file is part of elfutils.
+ Written by Ulrich Drepper <drepper@redhat.com>, 2003.
+
+ 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 <dwarf.h>
+#include "libdwP.h"
+
+
+Dwarf_Abbrev *
+internal_function
+__libdw_getabbrev (Dwarf *dbg, struct Dwarf_CU *cu, Dwarf_Off offset,
+ size_t *lengthp, Dwarf_Abbrev *result)
+{
+ /* Don't fail if there is not .debug_abbrev section. */
+ if (dbg->sectiondata[IDX_debug_abbrev] == NULL)
+ return NULL;
+
+ if (offset >= dbg->sectiondata[IDX_debug_abbrev]->d_size)
+ {
+ __libdw_seterrno (DWARF_E_INVALID_OFFSET);
+ return NULL;
+ }
+
+ const unsigned char *abbrevp
+ = (unsigned char *) dbg->sectiondata[IDX_debug_abbrev]->d_buf + offset;
+
+ if (*abbrevp == '\0')
+ /* We are past the last entry. */
+ return DWARF_END_ABBREV;
+
+ /* 7.5.3 Abbreviations Tables
+
+ [...] Each declaration begins with an unsigned LEB128 number
+ representing the abbreviation code itself. [...] The
+ abbreviation code is followed by another unsigned LEB128
+ number that encodes the entry's tag. [...]
+
+ [...] Following the tag encoding is a 1-byte value that
+ determines whether a debugging information entry using this
+ abbreviation has child entries or not. [...]
+
+ [...] Finally, the child encoding is followed by a series of
+ attribute specifications. Each attribute specification
+ consists of two parts. The first part is an unsigned LEB128
+ number representing the attribute's name. The second part is
+ an unsigned LEB128 number representing the attribute's form. */
+ const unsigned char *end = (dbg->sectiondata[IDX_debug_abbrev]->d_buf
+ + dbg->sectiondata[IDX_debug_abbrev]->d_size);
+ const unsigned char *start_abbrevp = abbrevp;
+ unsigned int code;
+ get_uleb128 (code, abbrevp, end);
+
+ /* Check whether this code is already in the hash table. */
+ bool foundit = false;
+ Dwarf_Abbrev *abb = NULL;
+ if (cu == NULL
+ || (abb = Dwarf_Abbrev_Hash_find (&cu->abbrev_hash, code, NULL)) == NULL)
+ {
+ if (result == NULL)
+ abb = libdw_typed_alloc (dbg, Dwarf_Abbrev);
+ else
+ abb = result;
+ }
+ else
+ {
+ foundit = true;
+
+ if (unlikely (abb->offset != offset))
+ {
+ /* A duplicate abbrev code at a different offset,
+ that should never happen. */
+ invalid:
+ __libdw_seterrno (DWARF_E_INVALID_DWARF);
+ return NULL;
+ }
+
+ /* If the caller doesn't need the length we are done. */
+ if (lengthp == NULL)
+ goto out;
+ }
+
+ /* If there is already a value in the hash table we are going to
+ overwrite its content. This must not be a problem, since the
+ content better be the same. */
+ abb->code = code;
+ if (abbrevp >= end)
+ goto invalid;
+ get_uleb128 (abb->tag, abbrevp, end);
+ if (abbrevp + 1 >= end)
+ goto invalid;
+ abb->has_children = *abbrevp++ == DW_CHILDREN_yes;
+ abb->attrp = (unsigned char *) abbrevp;
+ abb->offset = offset;
+
+ /* Skip over all the attributes and check rest of the abbrev is valid. */
+ unsigned int attrname;
+ unsigned int attrform;
+ do
+ {
+ if (abbrevp >= end)
+ goto invalid;
+ get_uleb128 (attrname, abbrevp, end);
+ if (abbrevp >= end)
+ goto invalid;
+ get_uleb128 (attrform, abbrevp, end);
+ }
+ while (attrname != 0 && attrform != 0);
+
+ /* Return the length to the caller if she asked for it. */
+ if (lengthp != NULL)
+ *lengthp = abbrevp - start_abbrevp;
+
+ /* Add the entry to the hash table. */
+ if (cu != NULL && ! foundit)
+ (void) Dwarf_Abbrev_Hash_insert (&cu->abbrev_hash, abb->code, abb);
+
+ out:
+ return abb;
+}
+
+
+Dwarf_Abbrev *
+dwarf_getabbrev (Dwarf_Die *die, Dwarf_Off offset, size_t *lengthp)
+{
+ return __libdw_getabbrev (die->cu->dbg, die->cu,
+ die->cu->orig_abbrev_offset + offset, lengthp,
+ NULL);
+}