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_getlocation_attr.c b/libdw/dwarf_getlocation_attr.c
new file mode 100644
index 0000000..e4dd708
--- /dev/null
+++ b/libdw/dwarf_getlocation_attr.c
@@ -0,0 +1,120 @@
+/* Return DWARF attribute associated with a location expression op.
+ Copyright (C) 2013, 2014 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 <dwarf.h>
+#include <libdwP.h>
+
+static Dwarf_CU *
+attr_form_cu (Dwarf_Attribute *attr)
+{
+ /* If the attribute has block/expr form the data comes from the
+ .debug_info from the same cu as the attr. Otherwise it comes from
+ the .debug_loc data section. */
+ switch (attr->form)
+ {
+ case DW_FORM_block1:
+ case DW_FORM_block2:
+ case DW_FORM_block4:
+ case DW_FORM_block:
+ case DW_FORM_exprloc:
+ return attr->cu;
+ default:
+ return attr->cu->dbg->fake_loc_cu;
+ }
+}
+
+int
+dwarf_getlocation_attr (Dwarf_Attribute *attr, const Dwarf_Op *op, Dwarf_Attribute *result)
+{
+ if (attr == NULL)
+ return -1;
+
+ switch (op->atom)
+ {
+ case DW_OP_implicit_value:
+ result->code = DW_AT_const_value;
+ result->form = DW_FORM_block;
+ result->valp = (unsigned char *) (uintptr_t) op->number2;
+ result->cu = attr_form_cu (attr);
+ break;
+
+ case DW_OP_GNU_entry_value:
+ result->code = DW_AT_location;
+ result->form = DW_FORM_exprloc;
+ result->valp = (unsigned char *) (uintptr_t) op->number2;
+ result->cu = attr_form_cu (attr);
+ break;
+
+ case DW_OP_GNU_const_type:
+ result->code = DW_AT_const_value;
+ result->form = DW_FORM_block1;
+ result->valp = (unsigned char *) (uintptr_t) op->number2;
+ result->cu = attr_form_cu (attr);
+ break;
+
+ case DW_OP_call2:
+ case DW_OP_call4:
+ case DW_OP_call_ref:
+ {
+ Dwarf_Die die;
+ if (INTUSE(dwarf_getlocation_die) (attr, op, &die) != 0)
+ return -1;
+ if (INTUSE(dwarf_attr) (&die, DW_AT_location, result) == NULL)
+ {
+ __libdw_empty_loc_attr (result);
+ return 0;
+ }
+ }
+ break;
+
+ case DW_OP_GNU_implicit_pointer:
+ case DW_OP_GNU_variable_value:
+ {
+ Dwarf_Die die;
+ if (INTUSE(dwarf_getlocation_die) (attr, op, &die) != 0)
+ return -1;
+ if (INTUSE(dwarf_attr) (&die, DW_AT_location, result) == NULL
+ && INTUSE(dwarf_attr) (&die, DW_AT_const_value, result) == NULL)
+ {
+ __libdw_empty_loc_attr (result);
+ return 0;
+ }
+ }
+ break;
+
+ default:
+ __libdw_seterrno (DWARF_E_INVALID_ACCESS);
+ return -1;
+ }
+
+ return 0;
+}