1cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng/* Function return value location for Linux/i386 ABI. 2cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Copyright (C) 2005, 2007 Red Hat, Inc. 3cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng This file is part of Red Hat elfutils. 4cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 5cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Red Hat elfutils is free software; you can redistribute it and/or modify 6cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng it under the terms of the GNU General Public License as published by the 7cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Free Software Foundation; version 2 of the License. 8cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 9cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Red Hat elfutils is distributed in the hope that it will be useful, but 10cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng WITHOUT ANY WARRANTY; without even the implied warranty of 11cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng General Public License for more details. 13cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 14cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng You should have received a copy of the GNU General Public License along 15cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng with Red Hat elfutils; if not, write to the Free Software Foundation, 16cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 17cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 18cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Red Hat elfutils is an included package of the Open Invention Network. 19cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng An included package of the Open Invention Network is a package for which 20cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Open Invention Network licensees cross-license their patents. No patent 21cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng license is granted, either expressly or impliedly, by designation as an 22cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng included package. Should you wish to participate in the Open Invention 23cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Network licensing program, please visit www.openinventionnetwork.com 24cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng <http://www.openinventionnetwork.com>. */ 25cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 26cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#ifdef HAVE_CONFIG_H 27cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng# include <config.h> 28cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#endif 29cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 30cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#include <assert.h> 31cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#include <dwarf.h> 32cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 33cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#define BACKEND i386_ 34cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#include "libebl_CPU.h" 35cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 36cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 37cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng/* %eax, or pair %eax, %edx. */ 38cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Chengstatic const Dwarf_Op loc_intreg[] = 39cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 40cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { .atom = DW_OP_reg0 }, { .atom = DW_OP_piece, .number = 4 }, 41cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { .atom = DW_OP_reg1 }, { .atom = DW_OP_piece, .number = 4 }, 42cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng }; 43cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#define nloc_intreg 1 44cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#define nloc_intregpair 4 45cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 46cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng/* %st(0). */ 47cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Chengstatic const Dwarf_Op loc_fpreg[] = 48cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 49cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { .atom = DW_OP_reg11 } 50cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng }; 51cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#define nloc_fpreg 1 52cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 53cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng/* The return value is a structure and is actually stored in stack space 54cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng passed in a hidden argument by the caller. But, the compiler 55cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng helpfully returns the address of that space in %eax. */ 56cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Chengstatic const Dwarf_Op loc_aggregate[] = 57cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 58cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { .atom = DW_OP_breg0, .number = 0 } 59cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng }; 60cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng#define nloc_aggregate 1 61cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 62cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Chengint 63cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Chengi386_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) 64cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng{ 65cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng /* Start with the function's type, and get the DW_AT_type attribute, 66cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng which is the type of the return value. */ 67cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 68cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Dwarf_Attribute attr_mem; 69cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Dwarf_Attribute *attr = dwarf_attr_integrate (functypedie, DW_AT_type, 70cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng &attr_mem); 71cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (attr == NULL) 72cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng /* The function has no return value, like a `void' function in C. */ 73cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return 0; 74cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 75cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Dwarf_Die die_mem; 76cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Dwarf_Die *typedie = dwarf_formref_die (attr, &die_mem); 77cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng int tag = dwarf_tag (typedie); 78cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 79cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng /* Follow typedefs and qualifiers to get to the actual type. */ 80cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng while (tag == DW_TAG_typedef 81cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng || tag == DW_TAG_const_type || tag == DW_TAG_volatile_type 82cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng || tag == DW_TAG_restrict_type || tag == DW_TAG_mutable_type) 83cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 84cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem); 85cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng typedie = dwarf_formref_die (attr, &die_mem); 86cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng tag = dwarf_tag (typedie); 87cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng } 88cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 89cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng switch (tag) 90cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 91cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case -1: 92cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return -1; 93cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 94cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case DW_TAG_subrange_type: 95cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size)) 96cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 97cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem); 98cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng typedie = dwarf_formref_die (attr, &die_mem); 99cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng tag = dwarf_tag (typedie); 100cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng } 101cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng /* Fall through. */ 102cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 103cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case DW_TAG_base_type: 104cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case DW_TAG_enumeration_type: 105cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case DW_TAG_pointer_type: 106cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case DW_TAG_ptr_to_member_type: 107cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 108cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Dwarf_Word size; 109cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size, 110cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng &attr_mem), &size) != 0) 111cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 112cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (tag == DW_TAG_pointer_type || tag == DW_TAG_ptr_to_member_type) 113cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng size = 4; 114cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng else 115cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return -1; 116cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng } 117cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (tag == DW_TAG_base_type) 118cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 119cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng Dwarf_Word encoding; 120cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_encoding, 121cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng &attr_mem), 122cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng &encoding) != 0) 123cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return -1; 124cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (encoding == DW_ATE_float) 125cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng { 126cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (size > 16) 127cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return -2; 128cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng *locp = loc_fpreg; 129cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return nloc_fpreg; 130cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng } 131cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng } 132cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng *locp = loc_intreg; 133cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (size <= 4) 134cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return nloc_intreg; 135cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng if (size <= 8) 136cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return nloc_intregpair; 137cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 138cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng /* Else fall through. */ 139cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng } 140cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 141cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case DW_TAG_structure_type: 142cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case DW_TAG_class_type: 143cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case DW_TAG_union_type: 144cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng case DW_TAG_array_type: 145cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng *locp = loc_aggregate; 146cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return nloc_aggregate; 147cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng } 148cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng 149cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng /* XXX We don't have a good way to return specific errors from ebl calls. 150cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng This value means we do not understand the type, but it is well-formed 151cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng DWARF and might be valid. */ 152cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng return -2; 153cc6695e2684ce93cdf8bd2da63d55d2cf49ff076Ben Cheng} 154