Roland McGrath | c373d85 | 2006-10-10 00:25:21 +0000 | [diff] [blame] | 1 | /* Function return value location for SPARC. |
Roland McGrath | c76f0b0 | 2007-09-27 07:31:33 +0000 | [diff] [blame^] | 2 | Copyright (C) 2006, 2007 Red Hat, Inc. |
Roland McGrath | c373d85 | 2006-10-10 00:25:21 +0000 | [diff] [blame] | 3 | |
| 4 | This program is Open Source software; you can redistribute it and/or |
| 5 | modify it under the terms of the Open Software License version 1.0 as |
| 6 | published by the Open Source Initiative. |
| 7 | |
| 8 | You should have received a copy of the Open Software License along |
| 9 | with this program; if not, you may obtain a copy of the Open Software |
| 10 | License version 1.0 from http://www.opensource.org/licenses/osl.php or |
| 11 | by writing the Open Source Initiative c/o Lawrence Rosen, Esq., |
| 12 | 3001 King Ranch Road, Ukiah, CA 95482. */ |
| 13 | |
| 14 | #ifdef HAVE_CONFIG_H |
| 15 | # include <config.h> |
| 16 | #endif |
| 17 | |
| 18 | #include <assert.h> |
| 19 | #include <dwarf.h> |
| 20 | |
| 21 | #define BACKEND sparc_ |
| 22 | #include "libebl_CPU.h" |
| 23 | |
| 24 | |
| 25 | /* %o0, or pair %o0, %o1. */ |
| 26 | static const Dwarf_Op loc_intreg[] = |
| 27 | { |
| 28 | { .atom = DW_OP_reg8 }, { .atom = DW_OP_piece, .number = 4 }, |
| 29 | { .atom = DW_OP_reg9 }, { .atom = DW_OP_piece, .number = 4 }, |
| 30 | }; |
| 31 | #define nloc_intreg 1 |
| 32 | #define nloc_intregpair 4 |
| 33 | |
| 34 | /* %f0 or pair %f0, %f1, or quad %f0..%f3. */ |
| 35 | static const Dwarf_Op loc_fpreg[] = |
| 36 | { |
| 37 | { .atom = DW_OP_regx, .number = 32 }, { .atom = DW_OP_piece, .number = 4 }, |
| 38 | { .atom = DW_OP_regx, .number = 33 }, { .atom = DW_OP_piece, .number = 4 }, |
| 39 | { .atom = DW_OP_regx, .number = 34 }, { .atom = DW_OP_piece, .number = 4 }, |
| 40 | { .atom = DW_OP_regx, .number = 35 }, { .atom = DW_OP_piece, .number = 4 }, |
| 41 | }; |
| 42 | #define nloc_fpreg 1 |
| 43 | #define nloc_fpregpair 4 |
| 44 | #define nloc_fpregquad 8 |
| 45 | |
| 46 | /* The return value is a structure and is actually stored in stack space |
| 47 | passed in a hidden argument by the caller. But, the compiler |
| 48 | helpfully returns the address of that space in %o0. */ |
| 49 | static const Dwarf_Op loc_aggregate[] = |
| 50 | { |
| 51 | { .atom = DW_OP_breg8, .number = 0 } |
| 52 | }; |
| 53 | #define nloc_aggregate 1 |
| 54 | |
| 55 | int |
| 56 | sparc_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) |
| 57 | { |
| 58 | /* Start with the function's type, and get the DW_AT_type attribute, |
| 59 | which is the type of the return value. */ |
| 60 | |
| 61 | Dwarf_Attribute attr_mem; |
Roland McGrath | c76f0b0 | 2007-09-27 07:31:33 +0000 | [diff] [blame^] | 62 | Dwarf_Attribute *attr = dwarf_attr_integrate (functypedie, DW_AT_type, |
| 63 | &attr_mem); |
Roland McGrath | c373d85 | 2006-10-10 00:25:21 +0000 | [diff] [blame] | 64 | if (attr == NULL) |
| 65 | /* The function has no return value, like a `void' function in C. */ |
| 66 | return 0; |
| 67 | |
| 68 | Dwarf_Die die_mem; |
| 69 | Dwarf_Die *typedie = dwarf_formref_die (attr, &die_mem); |
| 70 | int tag = dwarf_tag (typedie); |
| 71 | |
| 72 | /* Follow typedefs and qualifiers to get to the actual type. */ |
| 73 | while (tag == DW_TAG_typedef |
| 74 | || tag == DW_TAG_const_type || tag == DW_TAG_volatile_type |
| 75 | || tag == DW_TAG_restrict_type || tag == DW_TAG_mutable_type) |
| 76 | { |
Roland McGrath | c76f0b0 | 2007-09-27 07:31:33 +0000 | [diff] [blame^] | 77 | attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem); |
Roland McGrath | c373d85 | 2006-10-10 00:25:21 +0000 | [diff] [blame] | 78 | typedie = dwarf_formref_die (attr, &die_mem); |
| 79 | tag = dwarf_tag (typedie); |
| 80 | } |
| 81 | |
| 82 | Dwarf_Word size; |
| 83 | switch (tag) |
| 84 | { |
| 85 | case -1: |
| 86 | return -1; |
| 87 | |
| 88 | case DW_TAG_subrange_type: |
Roland McGrath | c76f0b0 | 2007-09-27 07:31:33 +0000 | [diff] [blame^] | 89 | if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size)) |
Roland McGrath | c373d85 | 2006-10-10 00:25:21 +0000 | [diff] [blame] | 90 | { |
Roland McGrath | c76f0b0 | 2007-09-27 07:31:33 +0000 | [diff] [blame^] | 91 | attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem); |
Roland McGrath | c373d85 | 2006-10-10 00:25:21 +0000 | [diff] [blame] | 92 | typedie = dwarf_formref_die (attr, &die_mem); |
| 93 | tag = dwarf_tag (typedie); |
| 94 | } |
| 95 | /* Fall through. */ |
| 96 | |
| 97 | case DW_TAG_base_type: |
| 98 | case DW_TAG_enumeration_type: |
| 99 | case DW_TAG_pointer_type: |
| 100 | case DW_TAG_ptr_to_member_type: |
Roland McGrath | c76f0b0 | 2007-09-27 07:31:33 +0000 | [diff] [blame^] | 101 | if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size, |
| 102 | &attr_mem), &size) != 0) |
Roland McGrath | c373d85 | 2006-10-10 00:25:21 +0000 | [diff] [blame] | 103 | { |
| 104 | uint8_t asize; |
| 105 | Dwarf_Die cudie; |
| 106 | if ((tag == DW_TAG_pointer_type || tag == DW_TAG_ptr_to_member_type) |
| 107 | && dwarf_diecu (typedie, &cudie, &asize, NULL) != NULL) |
| 108 | size = asize; |
| 109 | else |
| 110 | return -1; |
| 111 | } |
| 112 | if (tag == DW_TAG_base_type) |
| 113 | { |
| 114 | Dwarf_Word encoding; |
Roland McGrath | c76f0b0 | 2007-09-27 07:31:33 +0000 | [diff] [blame^] | 115 | if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_encoding, |
| 116 | &attr_mem), |
| 117 | &encoding) != 0) |
Roland McGrath | c373d85 | 2006-10-10 00:25:21 +0000 | [diff] [blame] | 118 | return -1; |
| 119 | if (encoding == DW_ATE_float) |
| 120 | { |
| 121 | *locp = loc_fpreg; |
| 122 | if (size <= 4) |
| 123 | return nloc_fpreg; |
| 124 | if (size <= 8) |
| 125 | return nloc_fpregpair; |
| 126 | if (size <= 16) |
| 127 | return nloc_fpregquad; |
| 128 | } |
| 129 | } |
| 130 | if (size <= 8) |
| 131 | { |
| 132 | intreg: |
| 133 | *locp = loc_intreg; |
| 134 | return size <= 4 ? nloc_intreg : nloc_intregpair; |
| 135 | } |
| 136 | |
| 137 | aggregate: |
| 138 | *locp = loc_aggregate; |
| 139 | return nloc_aggregate; |
| 140 | |
| 141 | case DW_TAG_structure_type: |
| 142 | case DW_TAG_class_type: |
| 143 | case DW_TAG_union_type: |
| 144 | case DW_TAG_array_type: |
Roland McGrath | c76f0b0 | 2007-09-27 07:31:33 +0000 | [diff] [blame^] | 145 | if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size, |
| 146 | &attr_mem), &size) == 0 |
Roland McGrath | c373d85 | 2006-10-10 00:25:21 +0000 | [diff] [blame] | 147 | && size > 0 && size <= 8) |
| 148 | goto intreg; |
| 149 | goto aggregate; |
| 150 | } |
| 151 | |
| 152 | /* XXX We don't have a good way to return specific errors from ebl calls. |
| 153 | This value means we do not understand the type, but it is well-formed |
| 154 | DWARF and might be valid. */ |
| 155 | return -2; |
| 156 | } |