diff options
Diffstat (limited to 'src/libdw/dwarf_getlocation_attr.c')
| -rw-r--r-- | src/libdw/dwarf_getlocation_attr.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/src/libdw/dwarf_getlocation_attr.c b/src/libdw/dwarf_getlocation_attr.c new file mode 100644 index 00000000..3229baf6 --- /dev/null +++ b/src/libdw/dwarf_getlocation_attr.c @@ -0,0 +1,122 @@ +/* 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 (attr, op, result) + 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: + { + 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; +} |