125b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* Function return value location for Linux/SH ABI. 225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Copyright (C) 2010 Red Hat, Inc. 325b3c049e70834cf33790a28643ab058b507b35cBen Cheng This file is part of Red Hat elfutils. 425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Contributed by Matt Fleming <matt@console-pimps.org>. 525b3c049e70834cf33790a28643ab058b507b35cBen Cheng 625b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is free software; you can redistribute it and/or modify 725b3c049e70834cf33790a28643ab058b507b35cBen Cheng it under the terms of the GNU General Public License as published by the 825b3c049e70834cf33790a28643ab058b507b35cBen Cheng Free Software Foundation; version 2 of the License. 925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1025b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is distributed in the hope that it will be useful, but 1125b3c049e70834cf33790a28643ab058b507b35cBen Cheng WITHOUT ANY WARRANTY; without even the implied warranty of 1225b3c049e70834cf33790a28643ab058b507b35cBen Cheng MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 1325b3c049e70834cf33790a28643ab058b507b35cBen Cheng General Public License for more details. 1425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1525b3c049e70834cf33790a28643ab058b507b35cBen Cheng You should have received a copy of the GNU General Public License along 1625b3c049e70834cf33790a28643ab058b507b35cBen Cheng with Red Hat elfutils; if not, write to the Free Software Foundation, 1725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 1825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1925b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is an included package of the Open Invention Network. 2025b3c049e70834cf33790a28643ab058b507b35cBen Cheng An included package of the Open Invention Network is a package for which 2125b3c049e70834cf33790a28643ab058b507b35cBen Cheng Open Invention Network licensees cross-license their patents. No patent 2225b3c049e70834cf33790a28643ab058b507b35cBen Cheng license is granted, either expressly or impliedly, by designation as an 2325b3c049e70834cf33790a28643ab058b507b35cBen Cheng included package. Should you wish to participate in the Open Invention 2425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Network licensing program, please visit www.openinventionnetwork.com 2525b3c049e70834cf33790a28643ab058b507b35cBen Cheng <http://www.openinventionnetwork.com>. */ 2625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 2725b3c049e70834cf33790a28643ab058b507b35cBen Cheng#ifdef HAVE_CONFIG_H 2825b3c049e70834cf33790a28643ab058b507b35cBen Cheng# include <config.h> 2925b3c049e70834cf33790a28643ab058b507b35cBen Cheng#endif 3025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 3125b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <assert.h> 3225b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <dwarf.h> 3325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 3425b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define BACKEND sh_ 3525b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include "libebl_CPU.h" 3625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 3725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 3825b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* This is the SVR4 ELF ABI convention, but AIX and Linux do not use it. */ 3925b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define SVR4_STRUCT_RETURN 0 4025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 4125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 4225b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* r0, or pair r0, r1. */ 4325b3c049e70834cf33790a28643ab058b507b35cBen Chengstatic const Dwarf_Op loc_intreg[] = 4425b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 4525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { .atom = DW_OP_reg0 }, { .atom = DW_OP_piece, .number = 4 }, 4625b3c049e70834cf33790a28643ab058b507b35cBen Cheng { .atom = DW_OP_reg1 }, { .atom = DW_OP_piece, .number = 4 }, 4725b3c049e70834cf33790a28643ab058b507b35cBen Cheng }; 4825b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define nloc_intreg 1 4925b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define nloc_intregpair 4 5025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5125b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* fr0 or fr1. */ 5225b3c049e70834cf33790a28643ab058b507b35cBen Chengstatic const Dwarf_Op loc_fpreg[] = 5325b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 5425b3c049e70834cf33790a28643ab058b507b35cBen Cheng { .atom = DW_OP_reg25 }, { .atom = DW_OP_piece, .number = 4 }, 5525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { .atom = DW_OP_reg26 }, { .atom = DW_OP_piece, .number = 4 }, 5625b3c049e70834cf33790a28643ab058b507b35cBen Cheng }; 5725b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define nloc_fpreg 1 5825b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define nloc_fpregpair 2 5925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6025b3c049e70834cf33790a28643ab058b507b35cBen Chengint 6125b3c049e70834cf33790a28643ab058b507b35cBen Chengsh_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) 6225b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 6325b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Start with the function's type, and get the DW_AT_type attribute, 6425b3c049e70834cf33790a28643ab058b507b35cBen Cheng which is the type of the return value. */ 6525b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6625b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Attribute attr_mem; 6725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Attribute *attr = dwarf_attr_integrate (functypedie, DW_AT_type, 6825b3c049e70834cf33790a28643ab058b507b35cBen Cheng &attr_mem); 6925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (attr == NULL) 7025b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* The function has no return value, like a `void' function in C. */ 7125b3c049e70834cf33790a28643ab058b507b35cBen Cheng return 0; 7225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 7325b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Die die_mem; 7425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Die *typedie = dwarf_formref_die (attr, &die_mem); 7525b3c049e70834cf33790a28643ab058b507b35cBen Cheng int tag = dwarf_tag (typedie); 7625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 7725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Follow typedefs and qualifiers to get to the actual type. */ 7825b3c049e70834cf33790a28643ab058b507b35cBen Cheng while (tag == DW_TAG_typedef 7925b3c049e70834cf33790a28643ab058b507b35cBen Cheng || tag == DW_TAG_const_type || tag == DW_TAG_volatile_type 8025b3c049e70834cf33790a28643ab058b507b35cBen Cheng || tag == DW_TAG_restrict_type || tag == DW_TAG_mutable_type) 8125b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 8225b3c049e70834cf33790a28643ab058b507b35cBen Cheng attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem); 8325b3c049e70834cf33790a28643ab058b507b35cBen Cheng typedie = dwarf_formref_die (attr, &die_mem); 8425b3c049e70834cf33790a28643ab058b507b35cBen Cheng tag = dwarf_tag (typedie); 8525b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 8625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 8725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Word size; 8825b3c049e70834cf33790a28643ab058b507b35cBen Cheng switch (tag) 8925b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 9025b3c049e70834cf33790a28643ab058b507b35cBen Cheng case -1: 9125b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 9225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 9325b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DW_TAG_subrange_type: 9425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size)) 9525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 9625b3c049e70834cf33790a28643ab058b507b35cBen Cheng attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem); 9725b3c049e70834cf33790a28643ab058b507b35cBen Cheng typedie = dwarf_formref_die (attr, &die_mem); 9825b3c049e70834cf33790a28643ab058b507b35cBen Cheng tag = dwarf_tag (typedie); 9925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 10025b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Fall through. */ 10125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 10225b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DW_TAG_base_type: 10325b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DW_TAG_enumeration_type: 10425b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DW_TAG_pointer_type: 10525b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DW_TAG_ptr_to_member_type: 10625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size, 10725b3c049e70834cf33790a28643ab058b507b35cBen Cheng &attr_mem), &size) != 0) 10825b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 10925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (tag == DW_TAG_pointer_type || tag == DW_TAG_ptr_to_member_type) 11025b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = 4; 11125b3c049e70834cf33790a28643ab058b507b35cBen Cheng else 11225b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 11325b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 11425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (size <= 8) 11525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 11625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (tag == DW_TAG_base_type) 11725b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 11825b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Word encoding; 11925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (dwarf_formudata (dwarf_attr_integrate (typedie, 12025b3c049e70834cf33790a28643ab058b507b35cBen Cheng DW_AT_encoding, 12125b3c049e70834cf33790a28643ab058b507b35cBen Cheng &attr_mem), 12225b3c049e70834cf33790a28643ab058b507b35cBen Cheng &encoding) != 0) 12325b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 12425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (encoding == DW_ATE_float) 12525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 12625b3c049e70834cf33790a28643ab058b507b35cBen Cheng *locp = loc_fpreg; 12725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return size <= 4 ? nloc_fpreg : nloc_fpregpair; 12825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 12925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 13025b3c049e70834cf33790a28643ab058b507b35cBen Cheng *locp = loc_intreg; 13125b3c049e70834cf33790a28643ab058b507b35cBen Cheng return size <= 4 ? nloc_intreg : nloc_intregpair; 13225b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 13325b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 13425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 13525b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* XXX We don't have a good way to return specific errors from ebl calls. 13625b3c049e70834cf33790a28643ab058b507b35cBen Cheng This value means we do not understand the type, but it is well-formed 13725b3c049e70834cf33790a28643ab058b507b35cBen Cheng DWARF and might be valid. */ 13825b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -2; 13925b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 140