1 | /* Language-level data type conversion for GNU C++. |
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2 | Copyright (C) 1987, 88, 92, 93, 94, 1995 Free Software Foundation, Inc. |
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3 | Hacked by Michael Tiemann (tiemann@cygnus.com) |
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4 | |
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5 | This file is part of GNU CC. |
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6 | |
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7 | GNU CC is free software; you can redistribute it and/or modify |
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8 | it under the terms of the GNU General Public License as published by |
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9 | the Free Software Foundation; either version 2, or (at your option) |
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10 | any later version. |
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11 | |
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12 | GNU CC is distributed in the hope that it will be useful, |
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13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | GNU General Public License for more details. |
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16 | |
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17 | You should have received a copy of the GNU General Public License |
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18 | along with GNU CC; see the file COPYING. If not, write to |
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19 | the Free Software Foundation, 59 Temple Place - Suite 330, |
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20 | Boston, MA 02111-1307, USA. */ |
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21 | |
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22 | |
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23 | /* This file contains the functions for converting C expressions |
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24 | to different data types. The only entry point is `convert'. |
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25 | Every language front end must have a `convert' function |
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26 | but what kind of conversions it does will depend on the language. */ |
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27 | |
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28 | #include "config.h" |
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29 | #include "tree.h" |
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30 | #include "flags.h" |
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31 | #include "cp-tree.h" |
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32 | #include "class.h" |
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33 | #include "convert.h" |
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34 | |
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35 | #undef NULL |
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36 | #define NULL (char *)0 |
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37 | |
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38 | /* Change of width--truncation and extension of integers or reals-- |
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39 | is represented with NOP_EXPR. Proper functioning of many things |
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40 | assumes that no other conversions can be NOP_EXPRs. |
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41 | |
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42 | Conversion between integer and pointer is represented with CONVERT_EXPR. |
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43 | Converting integer to real uses FLOAT_EXPR |
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44 | and real to integer uses FIX_TRUNC_EXPR. |
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45 | |
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46 | Here is a list of all the functions that assume that widening and |
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47 | narrowing is always done with a NOP_EXPR: |
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48 | In convert.c, convert_to_integer. |
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49 | In c-typeck.c, build_binary_op_nodefault (boolean ops), |
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50 | and truthvalue_conversion. |
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51 | In expr.c: expand_expr, for operands of a MULT_EXPR. |
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52 | In fold-const.c: fold. |
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53 | In tree.c: get_narrower and get_unwidened. |
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54 | |
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55 | C++: in multiple-inheritance, converting between pointers may involve |
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56 | adjusting them by a delta stored within the class definition. */ |
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57 | |
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58 | /* Subroutines of `convert'. */ |
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59 | |
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60 | /* Build a thunk. What it is, is an entry point that when called will |
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61 | adjust the this pointer (the first argument) by offset, and then |
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62 | goto the real address of the function given by REAL_ADDR that we |
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63 | would like called. What we return is the address of the thunk. */ |
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64 | static tree |
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65 | build_thunk (offset, real_addr) |
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66 | tree offset, real_addr; |
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67 | { |
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68 | if (TREE_CODE (real_addr) != ADDR_EXPR |
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69 | || TREE_CODE (TREE_OPERAND (real_addr, 0)) != FUNCTION_DECL) |
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70 | { |
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71 | sorry ("MI pointer to member conversion too complex"); |
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72 | return error_mark_node; |
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73 | } |
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74 | sorry ("MI pointer to member conversion too complex"); |
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75 | return error_mark_node; |
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76 | } |
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77 | |
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78 | /* Convert a `pointer to member' (POINTER_TYPE to METHOD_TYPE) into |
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79 | another `pointer to method'. This may involved the creation of |
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80 | a thunk to handle the this offset calculation. */ |
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81 | static tree |
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82 | convert_fn_ptr (type, expr) |
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83 | tree type, expr; |
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84 | { |
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85 | if (flag_vtable_thunks) |
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86 | { |
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87 | tree intype = TREE_TYPE (expr); |
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88 | tree binfo = get_binfo (TYPE_METHOD_BASETYPE (TREE_TYPE (intype)), |
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89 | TYPE_METHOD_BASETYPE (TREE_TYPE (type)), 1); |
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90 | if (binfo == error_mark_node) |
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91 | { |
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92 | error (" in pointer to member conversion"); |
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93 | return error_mark_node; |
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94 | } |
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95 | if (binfo == NULL_TREE) |
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96 | { |
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97 | /* ARM 4.8 restriction. */ |
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98 | error ("invalid pointer to member conversion"); |
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99 | return error_mark_node; |
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100 | } |
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101 | |
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102 | if (BINFO_OFFSET_ZEROP (binfo)) |
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103 | return build1 (NOP_EXPR, type, expr); |
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104 | return build1 (NOP_EXPR, type, build_thunk (BINFO_OFFSET (binfo), expr)); |
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105 | } |
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106 | else |
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107 | return build_ptrmemfunc (type, expr, 1); |
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108 | } |
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109 | |
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110 | /* if converting pointer to pointer |
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111 | if dealing with classes, check for derived->base or vice versa |
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112 | else if dealing with method pointers, delegate |
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113 | else convert blindly |
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114 | else if converting class, pass off to build_type_conversion |
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115 | else try C-style pointer conversion */ |
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116 | static tree |
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117 | cp_convert_to_pointer (type, expr) |
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118 | tree type, expr; |
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119 | { |
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120 | register tree intype = TREE_TYPE (expr); |
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121 | register enum tree_code form; |
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122 | |
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123 | if (TYPE_PTRMEMFUNC_P (type)) |
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124 | type = TYPE_PTRMEMFUNC_FN_TYPE (type); |
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125 | if (TYPE_PTRMEMFUNC_P (intype)) |
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126 | intype = TYPE_PTRMEMFUNC_FN_TYPE (intype); |
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127 | |
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128 | form = TREE_CODE (intype); |
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129 | |
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130 | if (form == POINTER_TYPE || form == REFERENCE_TYPE) |
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131 | { |
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132 | intype = TYPE_MAIN_VARIANT (intype); |
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133 | |
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134 | if (TYPE_MAIN_VARIANT (type) != intype |
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135 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE |
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136 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
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137 | { |
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138 | enum tree_code code = PLUS_EXPR; |
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139 | tree binfo = get_binfo (TREE_TYPE (type), TREE_TYPE (intype), 1); |
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140 | if (binfo == error_mark_node) |
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141 | return error_mark_node; |
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142 | if (binfo == NULL_TREE) |
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143 | { |
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144 | binfo = get_binfo (TREE_TYPE (intype), TREE_TYPE (type), 1); |
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145 | if (binfo == error_mark_node) |
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146 | return error_mark_node; |
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147 | code = MINUS_EXPR; |
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148 | } |
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149 | if (binfo) |
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150 | { |
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151 | if (TYPE_USES_VIRTUAL_BASECLASSES (TREE_TYPE (type)) |
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152 | || TYPE_USES_VIRTUAL_BASECLASSES (TREE_TYPE (intype)) |
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153 | || ! BINFO_OFFSET_ZEROP (binfo)) |
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154 | { |
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155 | /* Need to get the path we took. */ |
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156 | tree path; |
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157 | |
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158 | if (code == PLUS_EXPR) |
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159 | get_base_distance (TREE_TYPE (type), TREE_TYPE (intype), 0, &path); |
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160 | else |
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161 | get_base_distance (TREE_TYPE (intype), TREE_TYPE (type), 0, &path); |
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162 | return build_vbase_path (code, type, expr, path, 0); |
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163 | } |
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164 | } |
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165 | } |
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166 | if (TREE_CODE (TREE_TYPE (intype)) == METHOD_TYPE |
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167 | && TREE_CODE (type) == POINTER_TYPE |
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168 | && TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE) |
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169 | return convert_fn_ptr (type, expr); |
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170 | |
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171 | if (TREE_CODE (TREE_TYPE (type)) == OFFSET_TYPE |
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172 | && TREE_CODE (TREE_TYPE (intype)) == OFFSET_TYPE) |
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173 | { |
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174 | tree b1 = TYPE_OFFSET_BASETYPE (TREE_TYPE (type)); |
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175 | tree b2 = TYPE_OFFSET_BASETYPE (TREE_TYPE (intype)); |
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176 | tree binfo = get_binfo (b1, b2, 1); |
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177 | if (binfo == NULL_TREE) |
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178 | binfo = get_binfo (b2, b1, 1); |
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179 | if (binfo == error_mark_node) |
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180 | return error_mark_node; |
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181 | } |
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182 | |
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183 | if (TREE_CODE (TREE_TYPE (intype)) == METHOD_TYPE |
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184 | || (TREE_CODE (type) == POINTER_TYPE |
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185 | && TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE)) |
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186 | { |
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187 | cp_error ("cannot convert `%E' from type `%T' to type `%T'", |
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188 | expr, intype, type); |
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189 | return error_mark_node; |
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190 | } |
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191 | |
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192 | return build1 (NOP_EXPR, type, expr); |
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193 | } |
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194 | |
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195 | my_friendly_assert (form != OFFSET_TYPE, 186); |
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196 | |
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197 | if (TYPE_LANG_SPECIFIC (intype) |
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198 | && (IS_SIGNATURE_POINTER (intype) || IS_SIGNATURE_REFERENCE (intype))) |
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199 | return convert_to_pointer (type, build_optr_ref (expr)); |
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200 | |
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201 | if (IS_AGGR_TYPE (intype)) |
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202 | { |
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203 | tree rval; |
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204 | rval = build_type_conversion (CONVERT_EXPR, type, expr, 1); |
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205 | if (rval) |
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206 | { |
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207 | if (rval == error_mark_node) |
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208 | cp_error ("conversion of `%E' from `%T' to `%T' is ambiguous", |
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209 | expr, intype, type); |
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210 | return rval; |
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211 | } |
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212 | } |
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213 | |
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214 | if (integer_zerop (expr)) |
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215 | { |
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216 | if (type == TREE_TYPE (null_pointer_node)) |
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217 | return null_pointer_node; |
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218 | expr = build_int_2 (0, 0); |
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219 | TREE_TYPE (expr) = type; |
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220 | return expr; |
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221 | } |
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222 | |
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223 | if (INTEGRAL_CODE_P (form)) |
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224 | { |
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225 | if (type_precision (intype) == POINTER_SIZE) |
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226 | return build1 (CONVERT_EXPR, type, expr); |
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227 | expr = convert (type_for_size (POINTER_SIZE, 0), expr); |
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228 | /* Modes may be different but sizes should be the same. */ |
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229 | if (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr))) |
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230 | != GET_MODE_SIZE (TYPE_MODE (type))) |
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231 | /* There is supposed to be some integral type |
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232 | that is the same width as a pointer. */ |
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233 | abort (); |
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234 | return convert_to_pointer (type, expr); |
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235 | } |
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236 | |
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237 | cp_error ("cannot convert `%E' from type `%T' to type `%T'", |
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238 | expr, intype, type); |
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239 | return error_mark_node; |
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240 | } |
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241 | |
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242 | /* Like convert, except permit conversions to take place which |
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243 | are not normally allowed due to access restrictions |
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244 | (such as conversion from sub-type to private super-type). */ |
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245 | static tree |
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246 | convert_to_pointer_force (type, expr) |
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247 | tree type, expr; |
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248 | { |
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249 | register tree intype = TREE_TYPE (expr); |
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250 | register enum tree_code form = TREE_CODE (intype); |
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251 | |
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252 | if (integer_zerop (expr)) |
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253 | { |
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254 | if (type == TREE_TYPE (null_pointer_node)) |
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255 | return null_pointer_node; |
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256 | expr = build_int_2 (0, 0); |
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257 | TREE_TYPE (expr) = type; |
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258 | return expr; |
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259 | } |
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260 | |
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261 | /* Convert signature pointer/reference to `void *' first. */ |
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262 | if (form == RECORD_TYPE |
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263 | && (IS_SIGNATURE_POINTER (intype) || IS_SIGNATURE_REFERENCE (intype))) |
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264 | { |
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265 | expr = build_optr_ref (expr); |
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266 | intype = TREE_TYPE (expr); |
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267 | form = TREE_CODE (intype); |
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268 | } |
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269 | |
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270 | if (form == POINTER_TYPE) |
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271 | { |
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272 | intype = TYPE_MAIN_VARIANT (intype); |
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273 | |
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274 | if (TYPE_MAIN_VARIANT (type) != intype |
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275 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE |
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276 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
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277 | { |
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278 | enum tree_code code = PLUS_EXPR; |
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279 | tree path; |
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280 | int distance = get_base_distance (TREE_TYPE (type), |
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281 | TREE_TYPE (intype), 0, &path); |
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282 | if (distance == -2) |
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283 | { |
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284 | ambig: |
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285 | cp_error ("type `%T' is ambiguous baseclass of `%s'", TREE_TYPE (type), |
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286 | TYPE_NAME_STRING (TREE_TYPE (intype))); |
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287 | return error_mark_node; |
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288 | } |
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289 | if (distance == -1) |
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290 | { |
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291 | distance = get_base_distance (TREE_TYPE (intype), |
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292 | TREE_TYPE (type), 0, &path); |
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293 | if (distance == -2) |
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294 | goto ambig; |
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295 | if (distance < 0) |
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296 | /* Doesn't need any special help from us. */ |
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297 | return build1 (NOP_EXPR, type, expr); |
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298 | |
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299 | code = MINUS_EXPR; |
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300 | } |
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301 | return build_vbase_path (code, type, expr, path, 0); |
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302 | } |
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303 | return build1 (NOP_EXPR, type, expr); |
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304 | } |
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305 | |
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306 | return cp_convert_to_pointer (type, expr); |
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307 | } |
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308 | |
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309 | /* We are passing something to a function which requires a reference. |
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310 | The type we are interested in is in TYPE. The initial |
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311 | value we have to begin with is in ARG. |
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312 | |
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313 | FLAGS controls how we manage access checking. |
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314 | CHECKCONST controls if we report error messages on const subversion. */ |
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315 | static tree |
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316 | build_up_reference (type, arg, flags, checkconst) |
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317 | tree type, arg; |
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318 | int flags, checkconst; |
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319 | { |
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320 | tree rval, targ; |
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321 | int literal_flag = 0; |
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322 | tree argtype = TREE_TYPE (arg); |
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323 | tree target_type = TREE_TYPE (type); |
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324 | tree binfo = NULL_TREE; |
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325 | |
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326 | my_friendly_assert (TREE_CODE (type) == REFERENCE_TYPE, 187); |
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327 | if ((flags & LOOKUP_PROTECT) |
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328 | && TYPE_MAIN_VARIANT (argtype) != TYPE_MAIN_VARIANT (target_type) |
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329 | && IS_AGGR_TYPE (argtype) |
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330 | && IS_AGGR_TYPE (target_type)) |
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331 | { |
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332 | binfo = get_binfo (target_type, argtype, 1); |
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333 | if (binfo == error_mark_node) |
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334 | return error_mark_node; |
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335 | if (binfo == NULL_TREE) |
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336 | return error_not_base_type (target_type, argtype); |
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337 | } |
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338 | |
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339 | /* Pass along const and volatile down into the type. */ |
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340 | if (TYPE_READONLY (type) || TYPE_VOLATILE (type)) |
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341 | target_type = cp_build_type_variant (target_type, TYPE_READONLY (type), |
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342 | TYPE_VOLATILE (type)); |
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343 | targ = arg; |
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344 | if (TREE_CODE (targ) == SAVE_EXPR) |
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345 | targ = TREE_OPERAND (targ, 0); |
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346 | while (TREE_CODE (targ) == NOP_EXPR |
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347 | && (TYPE_MAIN_VARIANT (argtype) |
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348 | == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (targ, 0))))) |
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349 | targ = TREE_OPERAND (targ, 0); |
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350 | |
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351 | switch (TREE_CODE (targ)) |
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352 | { |
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353 | case INDIRECT_REF: |
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354 | /* This is a call to a constructor which did not know what it was |
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355 | initializing until now: it needs to initialize a temporary. */ |
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356 | if (TREE_HAS_CONSTRUCTOR (targ)) |
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357 | { |
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358 | tree temp = build_cplus_new (argtype, TREE_OPERAND (targ, 0), 1); |
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359 | TREE_HAS_CONSTRUCTOR (targ) = 0; |
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360 | return build_up_reference (type, temp, flags, 1); |
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361 | } |
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362 | /* Let &* cancel out to simplify resulting code. |
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363 | Also, throw away intervening NOP_EXPRs. */ |
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364 | arg = TREE_OPERAND (targ, 0); |
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365 | if (TREE_CODE (arg) == NOP_EXPR || TREE_CODE (arg) == NON_LVALUE_EXPR |
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366 | || (TREE_CODE (arg) == CONVERT_EXPR && TREE_REFERENCE_EXPR (arg))) |
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367 | arg = TREE_OPERAND (arg, 0); |
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368 | |
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369 | /* in doing a &*, we have to get rid of the const'ness on the pointer |
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370 | value. Haven't thought about volatile here. Pointers come to mind |
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371 | here. */ |
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372 | if (TREE_READONLY (arg)) |
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373 | { |
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374 | arg = copy_node (arg); |
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375 | TREE_READONLY (arg) = 0; |
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376 | } |
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377 | |
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378 | rval = build1 (CONVERT_EXPR, type, arg); |
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379 | TREE_REFERENCE_EXPR (rval) = 1; |
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380 | |
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381 | /* propagate the const flag on something like: |
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382 | |
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383 | class Base { |
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384 | public: |
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385 | int foo; |
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386 | }; |
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387 | |
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388 | class Derived : public Base { |
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389 | public: |
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390 | int bar; |
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391 | }; |
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392 | |
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393 | void func(Base&); |
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394 | |
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395 | void func2(const Derived& d) { |
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396 | func(d); |
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397 | } |
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398 | |
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399 | on the d parameter. The below could have been avoided, if the flags |
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400 | were down in the tree, not sure why they are not. (mrs) */ |
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401 | /* The below code may have to be propagated to other parts of this |
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402 | switch. */ |
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403 | if (TREE_READONLY (targ) && !TREE_READONLY (arg) |
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404 | && (TREE_CODE (arg) == PARM_DECL || TREE_CODE (arg) == VAR_DECL) |
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405 | && TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE |
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406 | && (TYPE_READONLY (target_type) && checkconst)) |
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407 | { |
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408 | arg = copy_node (arg); |
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409 | TREE_READONLY (arg) = TREE_READONLY (targ); |
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410 | } |
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411 | literal_flag = TREE_CONSTANT (arg); |
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412 | |
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413 | goto done; |
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414 | |
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415 | /* Get this out of a register if we happened to be in one by accident. |
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416 | Also, build up references to non-lvalues it we must. */ |
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417 | /* For &x[y], return (&) x+y */ |
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418 | case ARRAY_REF: |
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419 | if (mark_addressable (TREE_OPERAND (targ, 0)) == 0) |
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420 | return error_mark_node; |
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421 | rval = build_binary_op (PLUS_EXPR, TREE_OPERAND (targ, 0), |
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422 | TREE_OPERAND (targ, 1), 1); |
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423 | TREE_TYPE (rval) = type; |
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424 | if (TREE_CONSTANT (TREE_OPERAND (targ, 1)) |
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425 | && staticp (TREE_OPERAND (targ, 0))) |
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426 | TREE_CONSTANT (rval) = 1; |
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427 | goto done; |
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428 | |
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429 | case SCOPE_REF: |
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430 | /* Could be a reference to a static member. */ |
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431 | { |
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432 | tree field = TREE_OPERAND (targ, 1); |
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433 | if (TREE_STATIC (field)) |
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434 | { |
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435 | rval = build1 (ADDR_EXPR, type, field); |
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436 | literal_flag = 1; |
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437 | goto done; |
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438 | } |
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439 | } |
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440 | |
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441 | /* We should have farmed out member pointers above. */ |
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442 | my_friendly_abort (188); |
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443 | |
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444 | case COMPONENT_REF: |
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445 | rval = build_component_addr (targ, build_pointer_type (argtype), |
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446 | "attempt to make a reference to bit-field structure member `%s'"); |
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447 | TREE_TYPE (rval) = type; |
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448 | literal_flag = staticp (TREE_OPERAND (targ, 0)); |
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449 | |
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450 | goto done; |
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451 | |
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452 | /* Anything not already handled and not a true memory reference |
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453 | needs to have a reference built up. Do so silently for |
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454 | things like integers and return values from function, |
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455 | but complain if we need a reference to something declared |
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456 | as `register'. */ |
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457 | |
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458 | case RESULT_DECL: |
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459 | if (staticp (targ)) |
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460 | literal_flag = 1; |
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461 | TREE_ADDRESSABLE (targ) = 1; |
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462 | put_var_into_stack (targ); |
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463 | break; |
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464 | |
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465 | case PARM_DECL: |
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466 | #if 0 |
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467 | if (targ == current_class_decl) |
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468 | { |
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469 | error ("address of `this' not available"); |
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470 | /* #if 0 */ |
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471 | /* This code makes the following core dump the compiler on a sun4, |
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472 | if the code below is used. |
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473 | |
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474 | class e_decl; |
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475 | class a_decl; |
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476 | typedef a_decl* a_ref; |
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477 | |
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478 | class a_s { |
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479 | public: |
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480 | a_s(); |
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481 | void* append(a_ref& item); |
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482 | }; |
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483 | class a_decl { |
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484 | public: |
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485 | a_decl (e_decl *parent); |
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486 | a_s generic_s; |
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487 | a_s decls; |
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488 | e_decl* parent; |
---|
489 | }; |
---|
490 | |
---|
491 | class e_decl { |
---|
492 | public: |
---|
493 | e_decl(); |
---|
494 | a_s implementations; |
---|
495 | }; |
---|
496 | |
---|
497 | void foobar(void *); |
---|
498 | |
---|
499 | a_decl::a_decl(e_decl *parent) { |
---|
500 | parent->implementations.append(this); |
---|
501 | } |
---|
502 | */ |
---|
503 | |
---|
504 | TREE_ADDRESSABLE (targ) = 1; /* so compiler doesn't die later */ |
---|
505 | put_var_into_stack (targ); |
---|
506 | break; |
---|
507 | /* #else */ |
---|
508 | return error_mark_node; |
---|
509 | /* #endif */ |
---|
510 | } |
---|
511 | #endif |
---|
512 | /* Fall through. */ |
---|
513 | case VAR_DECL: |
---|
514 | case CONST_DECL: |
---|
515 | if (DECL_REGISTER (targ) && !TREE_ADDRESSABLE (targ) |
---|
516 | && !DECL_ARTIFICIAL (targ)) |
---|
517 | cp_warning ("address needed to build reference for `%D', which is declared `register'", |
---|
518 | targ); |
---|
519 | else if (staticp (targ)) |
---|
520 | literal_flag = 1; |
---|
521 | |
---|
522 | TREE_ADDRESSABLE (targ) = 1; |
---|
523 | put_var_into_stack (targ); |
---|
524 | break; |
---|
525 | |
---|
526 | case COMPOUND_EXPR: |
---|
527 | { |
---|
528 | tree real_reference = build_up_reference (type, TREE_OPERAND (targ, 1), |
---|
529 | LOOKUP_PROTECT, checkconst); |
---|
530 | rval = build (COMPOUND_EXPR, type, TREE_OPERAND (targ, 0), real_reference); |
---|
531 | TREE_CONSTANT (rval) = staticp (TREE_OPERAND (targ, 1)); |
---|
532 | return rval; |
---|
533 | } |
---|
534 | |
---|
535 | case PREINCREMENT_EXPR: |
---|
536 | case PREDECREMENT_EXPR: |
---|
537 | case MODIFY_EXPR: |
---|
538 | case INIT_EXPR: |
---|
539 | { |
---|
540 | tree real_reference = build_up_reference (type, TREE_OPERAND (targ, 0), |
---|
541 | LOOKUP_PROTECT, checkconst); |
---|
542 | rval = build (COMPOUND_EXPR, type, arg, real_reference); |
---|
543 | TREE_CONSTANT (rval) = staticp (TREE_OPERAND (targ, 0)); |
---|
544 | return rval; |
---|
545 | } |
---|
546 | |
---|
547 | case COND_EXPR: |
---|
548 | return build (COND_EXPR, type, |
---|
549 | TREE_OPERAND (targ, 0), |
---|
550 | build_up_reference (type, TREE_OPERAND (targ, 1), |
---|
551 | LOOKUP_PROTECT, checkconst), |
---|
552 | build_up_reference (type, TREE_OPERAND (targ, 2), |
---|
553 | LOOKUP_PROTECT, checkconst)); |
---|
554 | |
---|
555 | /* Undo the folding... */ |
---|
556 | case MIN_EXPR: |
---|
557 | case MAX_EXPR: |
---|
558 | return build (COND_EXPR, type, |
---|
559 | build (TREE_CODE (targ) == MIN_EXPR ? LT_EXPR : GT_EXPR, |
---|
560 | boolean_type_node, TREE_OPERAND (targ, 0), |
---|
561 | TREE_OPERAND (targ, 1)), |
---|
562 | build_up_reference (type, TREE_OPERAND (targ, 0), |
---|
563 | LOOKUP_PROTECT, checkconst), |
---|
564 | build_up_reference (type, TREE_OPERAND (targ, 1), |
---|
565 | LOOKUP_PROTECT, checkconst)); |
---|
566 | |
---|
567 | case WITH_CLEANUP_EXPR: |
---|
568 | return build (WITH_CLEANUP_EXPR, type, |
---|
569 | build_up_reference (type, TREE_OPERAND (targ, 0), |
---|
570 | LOOKUP_PROTECT, checkconst), |
---|
571 | 0, TREE_OPERAND (targ, 2)); |
---|
572 | |
---|
573 | case BIND_EXPR: |
---|
574 | arg = TREE_OPERAND (targ, 1); |
---|
575 | if (arg == NULL_TREE) |
---|
576 | { |
---|
577 | compiler_error ("({ ... }) expression not expanded when needed for reference"); |
---|
578 | return error_mark_node; |
---|
579 | } |
---|
580 | rval = build1 (ADDR_EXPR, type, arg); |
---|
581 | TREE_REFERENCE_EXPR (rval) = 1; |
---|
582 | return rval; |
---|
583 | |
---|
584 | default: |
---|
585 | break; |
---|
586 | } |
---|
587 | |
---|
588 | if (TREE_ADDRESSABLE (targ) == 0) |
---|
589 | { |
---|
590 | tree temp; |
---|
591 | |
---|
592 | if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (argtype)) |
---|
593 | { |
---|
594 | temp = build_cplus_new (argtype, targ, 1); |
---|
595 | if (TREE_CODE (temp) == WITH_CLEANUP_EXPR) |
---|
596 | rval = build (WITH_CLEANUP_EXPR, type, |
---|
597 | build1 (ADDR_EXPR, type, TREE_OPERAND (temp, 0)), |
---|
598 | 0, TREE_OPERAND (temp, 2)); |
---|
599 | else |
---|
600 | rval = build1 (ADDR_EXPR, type, temp); |
---|
601 | goto done; |
---|
602 | } |
---|
603 | else |
---|
604 | { |
---|
605 | temp = get_temp_name (argtype, 0); |
---|
606 | if (toplevel_bindings_p ()) |
---|
607 | { |
---|
608 | /* Give this new temp some rtl and initialize it. */ |
---|
609 | DECL_INITIAL (temp) = targ; |
---|
610 | TREE_STATIC (temp) = 1; |
---|
611 | cp_finish_decl (temp, targ, NULL_TREE, 0, LOOKUP_ONLYCONVERTING); |
---|
612 | /* Do this after declaring it static. */ |
---|
613 | rval = build_unary_op (ADDR_EXPR, temp, 0); |
---|
614 | TREE_TYPE (rval) = type; |
---|
615 | literal_flag = TREE_CONSTANT (rval); |
---|
616 | goto done; |
---|
617 | } |
---|
618 | else |
---|
619 | { |
---|
620 | rval = build_unary_op (ADDR_EXPR, temp, 0); |
---|
621 | if (binfo && !BINFO_OFFSET_ZEROP (binfo)) |
---|
622 | rval = convert_pointer_to (target_type, rval); |
---|
623 | else |
---|
624 | TREE_TYPE (rval) = type; |
---|
625 | |
---|
626 | temp = build (MODIFY_EXPR, argtype, temp, arg); |
---|
627 | TREE_SIDE_EFFECTS (temp) = 1; |
---|
628 | return build (COMPOUND_EXPR, type, temp, rval); |
---|
629 | } |
---|
630 | } |
---|
631 | } |
---|
632 | else |
---|
633 | rval = build1 (ADDR_EXPR, type, arg); |
---|
634 | |
---|
635 | done: |
---|
636 | if (TYPE_USES_COMPLEX_INHERITANCE (argtype) |
---|
637 | || TYPE_USES_COMPLEX_INHERITANCE (target_type)) |
---|
638 | { |
---|
639 | TREE_TYPE (rval) = build_pointer_type (argtype); |
---|
640 | if (flags & LOOKUP_PROTECT) |
---|
641 | rval = convert_pointer_to (target_type, rval); |
---|
642 | else |
---|
643 | rval |
---|
644 | = convert_to_pointer_force (build_pointer_type (target_type), rval); |
---|
645 | TREE_TYPE (rval) = type; |
---|
646 | if (TREE_CODE (rval) == PLUS_EXPR || TREE_CODE (rval) == MINUS_EXPR) |
---|
647 | TREE_TYPE (TREE_OPERAND (rval, 0)) |
---|
648 | = TREE_TYPE (TREE_OPERAND (rval, 1)) = type; |
---|
649 | } |
---|
650 | TREE_CONSTANT (rval) = literal_flag; |
---|
651 | return rval; |
---|
652 | } |
---|
653 | |
---|
654 | /* For C++: Only need to do one-level references, but cannot |
---|
655 | get tripped up on signed/unsigned differences. |
---|
656 | |
---|
657 | DECL is either NULL_TREE or the _DECL node for a reference that is being |
---|
658 | initialized. It can be error_mark_node if we don't know the _DECL but |
---|
659 | we know it's an initialization. */ |
---|
660 | |
---|
661 | tree |
---|
662 | convert_to_reference (reftype, expr, convtype, flags, decl) |
---|
663 | tree reftype, expr; |
---|
664 | int convtype, flags; |
---|
665 | tree decl; |
---|
666 | { |
---|
667 | register tree type = TYPE_MAIN_VARIANT (TREE_TYPE (reftype)); |
---|
668 | register tree intype = TREE_TYPE (expr); |
---|
669 | tree rval = NULL_TREE; |
---|
670 | tree rval_as_conversion = NULL_TREE; |
---|
671 | int i; |
---|
672 | |
---|
673 | if (TREE_CODE (intype) == REFERENCE_TYPE) |
---|
674 | my_friendly_abort (364); |
---|
675 | |
---|
676 | intype = TYPE_MAIN_VARIANT (intype); |
---|
677 | |
---|
678 | i = comp_target_types (type, intype, 0); |
---|
679 | |
---|
680 | if (i <= 0 && (convtype & CONV_IMPLICIT) && IS_AGGR_TYPE (intype) |
---|
681 | && ! (flags & LOOKUP_NO_CONVERSION)) |
---|
682 | { |
---|
683 | /* Look for a user-defined conversion to lvalue that we can use. */ |
---|
684 | |
---|
685 | rval_as_conversion = build_type_conversion (CONVERT_EXPR, type, expr, 1); |
---|
686 | |
---|
687 | if (rval_as_conversion && rval_as_conversion != error_mark_node |
---|
688 | && real_lvalue_p (rval_as_conversion)) |
---|
689 | { |
---|
690 | expr = rval_as_conversion; |
---|
691 | rval_as_conversion = NULL_TREE; |
---|
692 | intype = type; |
---|
693 | i = 1; |
---|
694 | } |
---|
695 | } |
---|
696 | |
---|
697 | if (((convtype & CONV_STATIC) && i == -1) |
---|
698 | || ((convtype & CONV_IMPLICIT) && i == 1)) |
---|
699 | { |
---|
700 | if (flags & LOOKUP_COMPLAIN) |
---|
701 | { |
---|
702 | tree ttl = TREE_TYPE (reftype); |
---|
703 | tree ttr; |
---|
704 | |
---|
705 | { |
---|
706 | int r = TREE_READONLY (expr); |
---|
707 | int v = TREE_THIS_VOLATILE (expr); |
---|
708 | ttr = cp_build_type_variant (TREE_TYPE (expr), r, v); |
---|
709 | } |
---|
710 | |
---|
711 | if (! real_lvalue_p (expr) && |
---|
712 | (decl == NULL_TREE || ! TYPE_READONLY (ttl))) |
---|
713 | { |
---|
714 | if (decl) |
---|
715 | /* Ensure semantics of [dcl.init.ref] */ |
---|
716 | cp_pedwarn ("initialization of non-const `%T' from rvalue `%T'", |
---|
717 | reftype, intype); |
---|
718 | else |
---|
719 | cp_pedwarn ("conversion to `%T' from rvalue `%T'", |
---|
720 | reftype, intype); |
---|
721 | } |
---|
722 | else if (! (convtype & CONV_CONST)) |
---|
723 | { |
---|
724 | if (! TYPE_READONLY (ttl) && TYPE_READONLY (ttr)) |
---|
725 | cp_pedwarn ("conversion from `%T' to `%T' discards const", |
---|
726 | ttr, reftype); |
---|
727 | else if (! TYPE_VOLATILE (ttl) && TYPE_VOLATILE (ttr)) |
---|
728 | cp_pedwarn ("conversion from `%T' to `%T' discards volatile", |
---|
729 | ttr, reftype); |
---|
730 | } |
---|
731 | } |
---|
732 | |
---|
733 | return build_up_reference (reftype, expr, flags, |
---|
734 | ! (convtype & CONV_CONST)); |
---|
735 | } |
---|
736 | else if ((convtype & CONV_REINTERPRET) && lvalue_p (expr)) |
---|
737 | { |
---|
738 | /* When casting an lvalue to a reference type, just convert into |
---|
739 | a pointer to the new type and deference it. This is allowed |
---|
740 | by San Diego WP section 5.2.9 paragraph 12, though perhaps it |
---|
741 | should be done directly (jason). (int &)ri ---> *(int*)&ri */ |
---|
742 | |
---|
743 | /* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they |
---|
744 | meant. */ |
---|
745 | if (TREE_CODE (intype) == POINTER_TYPE |
---|
746 | && (comptypes (TREE_TYPE (intype), type, -1))) |
---|
747 | cp_warning ("casting `%T' to `%T' does not dereference pointer", |
---|
748 | intype, reftype); |
---|
749 | |
---|
750 | rval = build_unary_op (ADDR_EXPR, expr, 0); |
---|
751 | if (rval != error_mark_node) |
---|
752 | rval = convert_force (build_pointer_type (TREE_TYPE (reftype)), rval, 0); |
---|
753 | if (rval != error_mark_node) |
---|
754 | rval = build1 (NOP_EXPR, reftype, rval); |
---|
755 | } |
---|
756 | else if (decl) |
---|
757 | { |
---|
758 | tree rval_as_ctor = NULL_TREE; |
---|
759 | |
---|
760 | if (rval_as_conversion) |
---|
761 | { |
---|
762 | if (rval_as_conversion == error_mark_node) |
---|
763 | { |
---|
764 | cp_error ("conversion from `%T' to `%T' is ambiguous", |
---|
765 | intype, reftype); |
---|
766 | return error_mark_node; |
---|
767 | } |
---|
768 | rval_as_conversion = build_up_reference (reftype, rval_as_conversion, |
---|
769 | flags, 1); |
---|
770 | } |
---|
771 | |
---|
772 | /* Definitely need to go through a constructor here. */ |
---|
773 | if (TYPE_HAS_CONSTRUCTOR (type) |
---|
774 | && ! CLASSTYPE_ABSTRACT_VIRTUALS (type) |
---|
775 | && (rval = build_method_call |
---|
776 | (NULL_TREE, constructor_name_full (type), |
---|
777 | build_tree_list (NULL_TREE, expr), TYPE_BINFO (type), |
---|
778 | LOOKUP_NO_CONVERSION|LOOKUP_SPECULATIVELY |
---|
779 | | LOOKUP_ONLYCONVERTING))) |
---|
780 | { |
---|
781 | tree init; |
---|
782 | |
---|
783 | if (toplevel_bindings_p ()) |
---|
784 | { |
---|
785 | extern tree static_aggregates; |
---|
786 | tree t = get_temp_name (type, toplevel_bindings_p ()); |
---|
787 | init = build_method_call (t, constructor_name_full (type), |
---|
788 | build_tree_list (NULL_TREE, expr), |
---|
789 | TYPE_BINFO (type), |
---|
790 | LOOKUP_NORMAL|LOOKUP_NO_CONVERSION |
---|
791 | | LOOKUP_ONLYCONVERTING); |
---|
792 | |
---|
793 | if (init == error_mark_node) |
---|
794 | return error_mark_node; |
---|
795 | |
---|
796 | make_decl_rtl (t, NULL_PTR, 1); |
---|
797 | static_aggregates = perm_tree_cons (expr, t, static_aggregates); |
---|
798 | rval = build_unary_op (ADDR_EXPR, t, 0); |
---|
799 | } |
---|
800 | else |
---|
801 | { |
---|
802 | init = build_method_call (NULL_TREE, constructor_name_full (type), |
---|
803 | build_tree_list (NULL_TREE, expr), |
---|
804 | TYPE_BINFO (type), |
---|
805 | LOOKUP_NORMAL|LOOKUP_NO_CONVERSION |
---|
806 | |LOOKUP_ONLYCONVERTING); |
---|
807 | |
---|
808 | if (init == error_mark_node) |
---|
809 | return error_mark_node; |
---|
810 | |
---|
811 | rval = build_cplus_new (type, init, 1); |
---|
812 | rval = build_up_reference (reftype, rval, flags, 1); |
---|
813 | } |
---|
814 | rval_as_ctor = rval; |
---|
815 | } |
---|
816 | |
---|
817 | if (rval_as_ctor && rval_as_conversion) |
---|
818 | { |
---|
819 | cp_error ("ambiguous conversion from `%T' to `%T'; both user-defined conversion and constructor apply", |
---|
820 | intype, reftype); |
---|
821 | return error_mark_node; |
---|
822 | } |
---|
823 | else if (rval_as_ctor) |
---|
824 | rval = rval_as_ctor; |
---|
825 | else if (rval_as_conversion) |
---|
826 | rval = rval_as_conversion; |
---|
827 | else if (! IS_AGGR_TYPE (type) && ! IS_AGGR_TYPE (intype)) |
---|
828 | { |
---|
829 | rval = convert (type, expr); |
---|
830 | if (rval == error_mark_node) |
---|
831 | return error_mark_node; |
---|
832 | |
---|
833 | rval = build_up_reference (reftype, rval, flags, 1); |
---|
834 | } |
---|
835 | |
---|
836 | if (rval && ! TYPE_READONLY (TREE_TYPE (reftype))) |
---|
837 | cp_pedwarn ("initializing non-const `%T' with `%T' will use a temporary", |
---|
838 | reftype, intype); |
---|
839 | } |
---|
840 | |
---|
841 | if (rval) |
---|
842 | { |
---|
843 | /* If we found a way to convert earlier, then use it. */ |
---|
844 | return rval; |
---|
845 | } |
---|
846 | |
---|
847 | my_friendly_assert (TREE_CODE (intype) != OFFSET_TYPE, 189); |
---|
848 | |
---|
849 | if (flags & LOOKUP_COMPLAIN) |
---|
850 | cp_error ("cannot convert type `%T' to type `%T'", intype, reftype); |
---|
851 | |
---|
852 | if (flags & LOOKUP_SPECULATIVELY) |
---|
853 | return NULL_TREE; |
---|
854 | |
---|
855 | return error_mark_node; |
---|
856 | } |
---|
857 | |
---|
858 | /* We are using a reference VAL for its value. Bash that reference all the |
---|
859 | way down to its lowest form. */ |
---|
860 | tree |
---|
861 | convert_from_reference (val) |
---|
862 | tree val; |
---|
863 | { |
---|
864 | tree type = TREE_TYPE (val); |
---|
865 | |
---|
866 | if (TREE_CODE (type) == OFFSET_TYPE) |
---|
867 | type = TREE_TYPE (type); |
---|
868 | if (TREE_CODE (type) == REFERENCE_TYPE) |
---|
869 | return build_indirect_ref (val, NULL_PTR); |
---|
870 | return val; |
---|
871 | } |
---|
872 | |
---|
873 | /* See if there is a constructor of type TYPE which will convert |
---|
874 | EXPR. The reference manual seems to suggest (8.5.6) that we need |
---|
875 | not worry about finding constructors for base classes, then converting |
---|
876 | to the derived class. |
---|
877 | |
---|
878 | MSGP is a pointer to a message that would be an appropriate error |
---|
879 | string. If MSGP is NULL, then we are not interested in reporting |
---|
880 | errors. */ |
---|
881 | tree |
---|
882 | convert_to_aggr (type, expr, msgp, protect) |
---|
883 | tree type, expr; |
---|
884 | char **msgp; |
---|
885 | int protect; |
---|
886 | { |
---|
887 | tree basetype = type; |
---|
888 | tree name = TYPE_IDENTIFIER (basetype); |
---|
889 | tree function, fndecl, fntype, parmtypes, parmlist, result; |
---|
890 | tree method_name; |
---|
891 | enum access_type access; |
---|
892 | int can_be_private, can_be_protected; |
---|
893 | |
---|
894 | if (! TYPE_HAS_CONSTRUCTOR (basetype)) |
---|
895 | { |
---|
896 | if (msgp) |
---|
897 | *msgp = "type `%s' does not have a constructor"; |
---|
898 | return error_mark_node; |
---|
899 | } |
---|
900 | |
---|
901 | access = access_public; |
---|
902 | can_be_private = 0; |
---|
903 | can_be_protected = IDENTIFIER_CLASS_VALUE (name) || name == current_class_name; |
---|
904 | |
---|
905 | parmlist = build_tree_list (NULL_TREE, expr); |
---|
906 | parmtypes = tree_cons (NULL_TREE, TREE_TYPE (expr), void_list_node); |
---|
907 | |
---|
908 | if (TYPE_USES_VIRTUAL_BASECLASSES (basetype)) |
---|
909 | { |
---|
910 | parmtypes = tree_cons (NULL_TREE, integer_type_node, parmtypes); |
---|
911 | parmlist = tree_cons (NULL_TREE, integer_one_node, parmlist); |
---|
912 | } |
---|
913 | |
---|
914 | /* The type of the first argument will be filled in inside the loop. */ |
---|
915 | parmlist = tree_cons (NULL_TREE, integer_zero_node, parmlist); |
---|
916 | parmtypes = tree_cons (NULL_TREE, build_pointer_type (basetype), parmtypes); |
---|
917 | |
---|
918 | #if 0 |
---|
919 | method_name = build_decl_overload (name, parmtypes, 1); |
---|
920 | |
---|
921 | /* constructors are up front. */ |
---|
922 | fndecl = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (basetype), 0); |
---|
923 | if (TYPE_HAS_DESTRUCTOR (basetype)) |
---|
924 | fndecl = DECL_CHAIN (fndecl); |
---|
925 | |
---|
926 | while (fndecl) |
---|
927 | { |
---|
928 | if (DECL_ASSEMBLER_NAME (fndecl) == method_name) |
---|
929 | { |
---|
930 | function = fndecl; |
---|
931 | if (protect) |
---|
932 | { |
---|
933 | if (TREE_PRIVATE (fndecl)) |
---|
934 | { |
---|
935 | can_be_private = |
---|
936 | (basetype == current_class_type |
---|
937 | || is_friend (basetype, current_function_decl) |
---|
938 | || purpose_member (basetype, DECL_ACCESS (fndecl))); |
---|
939 | if (! can_be_private) |
---|
940 | goto found; |
---|
941 | } |
---|
942 | else if (TREE_PROTECTED (fndecl)) |
---|
943 | { |
---|
944 | if (! can_be_protected) |
---|
945 | goto found; |
---|
946 | } |
---|
947 | } |
---|
948 | goto found_and_ok; |
---|
949 | } |
---|
950 | fndecl = DECL_CHAIN (fndecl); |
---|
951 | } |
---|
952 | #endif |
---|
953 | |
---|
954 | /* No exact conversion was found. See if an approximate |
---|
955 | one will do. */ |
---|
956 | fndecl = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (basetype), 0); |
---|
957 | if (TYPE_HAS_DESTRUCTOR (basetype)) |
---|
958 | fndecl = DECL_CHAIN (fndecl); |
---|
959 | |
---|
960 | { |
---|
961 | int saw_private = 0; |
---|
962 | int saw_protected = 0; |
---|
963 | struct candidate *candidates = |
---|
964 | (struct candidate *) alloca ((decl_list_length (fndecl)+1) * sizeof (struct candidate)); |
---|
965 | struct candidate *cp = candidates; |
---|
966 | |
---|
967 | while (fndecl) |
---|
968 | { |
---|
969 | function = fndecl; |
---|
970 | cp->h_len = 2; |
---|
971 | cp->harshness = (struct harshness_code *) |
---|
972 | alloca (3 * sizeof (struct harshness_code)); |
---|
973 | |
---|
974 | compute_conversion_costs (fndecl, parmlist, cp, 2); |
---|
975 | if ((cp->h.code & EVIL_CODE) == 0) |
---|
976 | { |
---|
977 | cp->u.field = fndecl; |
---|
978 | if (protect) |
---|
979 | { |
---|
980 | if (TREE_PRIVATE (fndecl)) |
---|
981 | access = access_private; |
---|
982 | else if (TREE_PROTECTED (fndecl)) |
---|
983 | access = access_protected; |
---|
984 | else |
---|
985 | access = access_public; |
---|
986 | } |
---|
987 | else |
---|
988 | access = access_public; |
---|
989 | |
---|
990 | if (access == access_private |
---|
991 | ? (basetype == current_class_type |
---|
992 | || is_friend (basetype, cp->function) |
---|
993 | || purpose_member (basetype, DECL_ACCESS (fndecl))) |
---|
994 | : access == access_protected |
---|
995 | ? (can_be_protected |
---|
996 | || purpose_member (basetype, DECL_ACCESS (fndecl))) |
---|
997 | : 1) |
---|
998 | { |
---|
999 | if (cp->h.code <= TRIVIAL_CODE) |
---|
1000 | goto found_and_ok; |
---|
1001 | cp++; |
---|
1002 | } |
---|
1003 | else |
---|
1004 | { |
---|
1005 | if (access == access_private) |
---|
1006 | saw_private = 1; |
---|
1007 | else |
---|
1008 | saw_protected = 1; |
---|
1009 | } |
---|
1010 | } |
---|
1011 | fndecl = DECL_CHAIN (fndecl); |
---|
1012 | } |
---|
1013 | if (cp - candidates) |
---|
1014 | { |
---|
1015 | /* Rank from worst to best. Then cp will point to best one. |
---|
1016 | Private fields have their bits flipped. For unsigned |
---|
1017 | numbers, this should make them look very large. |
---|
1018 | If the best alternate has a (signed) negative value, |
---|
1019 | then all we ever saw were private members. */ |
---|
1020 | if (cp - candidates > 1) |
---|
1021 | qsort (candidates, /* char *base */ |
---|
1022 | cp - candidates, /* int nel */ |
---|
1023 | sizeof (struct candidate), /* int width */ |
---|
1024 | rank_for_overload); /* int (*compar)() */ |
---|
1025 | |
---|
1026 | --cp; |
---|
1027 | if (cp->h.code & EVIL_CODE) |
---|
1028 | { |
---|
1029 | if (msgp) |
---|
1030 | *msgp = "ambiguous type conversion possible for `%s'"; |
---|
1031 | return error_mark_node; |
---|
1032 | } |
---|
1033 | |
---|
1034 | function = cp->function; |
---|
1035 | fndecl = cp->u.field; |
---|
1036 | goto found_and_ok; |
---|
1037 | } |
---|
1038 | else if (msgp) |
---|
1039 | { |
---|
1040 | if (saw_private) |
---|
1041 | if (saw_protected) |
---|
1042 | *msgp = "only private and protected conversions apply"; |
---|
1043 | else |
---|
1044 | *msgp = "only private conversions apply"; |
---|
1045 | else if (saw_protected) |
---|
1046 | *msgp = "only protected conversions apply"; |
---|
1047 | else |
---|
1048 | *msgp = "no appropriate conversion to type `%s'"; |
---|
1049 | } |
---|
1050 | return error_mark_node; |
---|
1051 | } |
---|
1052 | /* NOTREACHED */ |
---|
1053 | |
---|
1054 | found: |
---|
1055 | if (access == access_private) |
---|
1056 | if (! can_be_private) |
---|
1057 | { |
---|
1058 | if (msgp) |
---|
1059 | *msgp = TREE_PRIVATE (fndecl) |
---|
1060 | ? "conversion to type `%s' is private" |
---|
1061 | : "conversion to type `%s' is from private base class"; |
---|
1062 | return error_mark_node; |
---|
1063 | } |
---|
1064 | if (access == access_protected) |
---|
1065 | if (! can_be_protected) |
---|
1066 | { |
---|
1067 | if (msgp) |
---|
1068 | *msgp = TREE_PRIVATE (fndecl) |
---|
1069 | ? "conversion to type `%s' is protected" |
---|
1070 | : "conversion to type `%s' is from protected base class"; |
---|
1071 | return error_mark_node; |
---|
1072 | } |
---|
1073 | function = fndecl; |
---|
1074 | found_and_ok: |
---|
1075 | |
---|
1076 | /* It will convert, but we don't do anything about it yet. */ |
---|
1077 | if (msgp == 0) |
---|
1078 | return NULL_TREE; |
---|
1079 | |
---|
1080 | fntype = TREE_TYPE (function); |
---|
1081 | function = default_conversion (function); |
---|
1082 | |
---|
1083 | result = build_nt (CALL_EXPR, function, |
---|
1084 | convert_arguments (NULL_TREE, TYPE_ARG_TYPES (fntype), |
---|
1085 | parmlist, NULL_TREE, LOOKUP_NORMAL), |
---|
1086 | NULL_TREE); |
---|
1087 | TREE_TYPE (result) = TREE_TYPE (fntype); |
---|
1088 | TREE_SIDE_EFFECTS (result) = 1; |
---|
1089 | return result; |
---|
1090 | } |
---|
1091 | |
---|
1092 | /* Call this when we know (for any reason) that expr is not, in fact, |
---|
1093 | zero. This routine is like convert_pointer_to, but it pays |
---|
1094 | attention to which specific instance of what type we want to |
---|
1095 | convert to. This routine should eventually become |
---|
1096 | convert_to_pointer after all references to convert_to_pointer |
---|
1097 | are removed. */ |
---|
1098 | tree |
---|
1099 | convert_pointer_to_real (binfo, expr) |
---|
1100 | tree binfo, expr; |
---|
1101 | { |
---|
1102 | register tree intype = TREE_TYPE (expr); |
---|
1103 | tree ptr_type; |
---|
1104 | tree type, rval; |
---|
1105 | |
---|
1106 | if (TREE_CODE (binfo) == TREE_VEC) |
---|
1107 | type = BINFO_TYPE (binfo); |
---|
1108 | else if (IS_AGGR_TYPE (binfo)) |
---|
1109 | { |
---|
1110 | type = binfo; |
---|
1111 | } |
---|
1112 | else |
---|
1113 | { |
---|
1114 | type = binfo; |
---|
1115 | binfo = NULL_TREE; |
---|
1116 | } |
---|
1117 | |
---|
1118 | ptr_type = build_pointer_type (type); |
---|
1119 | if (ptr_type == TYPE_MAIN_VARIANT (intype)) |
---|
1120 | return expr; |
---|
1121 | |
---|
1122 | if (intype == error_mark_node) |
---|
1123 | return error_mark_node; |
---|
1124 | |
---|
1125 | my_friendly_assert (!integer_zerop (expr), 191); |
---|
1126 | |
---|
1127 | if (TREE_CODE (type) == RECORD_TYPE |
---|
1128 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE |
---|
1129 | && type != TYPE_MAIN_VARIANT (TREE_TYPE (intype))) |
---|
1130 | { |
---|
1131 | tree path; |
---|
1132 | int distance |
---|
1133 | = get_base_distance (binfo, TYPE_MAIN_VARIANT (TREE_TYPE (intype)), |
---|
1134 | 0, &path); |
---|
1135 | |
---|
1136 | /* This function shouldn't be called with unqualified arguments |
---|
1137 | but if it is, give them an error message that they can read. */ |
---|
1138 | if (distance < 0) |
---|
1139 | { |
---|
1140 | cp_error ("cannot convert a pointer of type `%T' to a pointer of type `%T'", |
---|
1141 | TREE_TYPE (intype), type); |
---|
1142 | |
---|
1143 | if (distance == -2) |
---|
1144 | cp_error ("because `%T' is an ambiguous base class", type); |
---|
1145 | return error_mark_node; |
---|
1146 | } |
---|
1147 | |
---|
1148 | return build_vbase_path (PLUS_EXPR, ptr_type, expr, path, 1); |
---|
1149 | } |
---|
1150 | rval = build1 (NOP_EXPR, ptr_type, |
---|
1151 | TREE_CODE (expr) == NOP_EXPR ? TREE_OPERAND (expr, 0) : expr); |
---|
1152 | TREE_CONSTANT (rval) = TREE_CONSTANT (expr); |
---|
1153 | return rval; |
---|
1154 | } |
---|
1155 | |
---|
1156 | /* Call this when we know (for any reason) that expr is |
---|
1157 | not, in fact, zero. This routine gets a type out of the first |
---|
1158 | argument and uses it to search for the type to convert to. If there |
---|
1159 | is more than one instance of that type in the expr, the conversion is |
---|
1160 | ambiguous. This routine should eventually go away, and all |
---|
1161 | callers should use convert_to_pointer_real. */ |
---|
1162 | tree |
---|
1163 | convert_pointer_to (binfo, expr) |
---|
1164 | tree binfo, expr; |
---|
1165 | { |
---|
1166 | tree type; |
---|
1167 | |
---|
1168 | if (TREE_CODE (binfo) == TREE_VEC) |
---|
1169 | type = BINFO_TYPE (binfo); |
---|
1170 | else if (IS_AGGR_TYPE (binfo)) |
---|
1171 | type = binfo; |
---|
1172 | else |
---|
1173 | type = binfo; |
---|
1174 | return convert_pointer_to_real (type, expr); |
---|
1175 | } |
---|
1176 | |
---|
1177 | /* Conversion... |
---|
1178 | |
---|
1179 | FLAGS indicates how we should behave. */ |
---|
1180 | |
---|
1181 | tree |
---|
1182 | cp_convert (type, expr, convtype, flags) |
---|
1183 | tree type, expr; |
---|
1184 | int convtype, flags; |
---|
1185 | { |
---|
1186 | register tree e = expr; |
---|
1187 | register enum tree_code code = TREE_CODE (type); |
---|
1188 | |
---|
1189 | if (TREE_CODE (e) == ERROR_MARK |
---|
1190 | || TREE_CODE (TREE_TYPE (e)) == ERROR_MARK) |
---|
1191 | return error_mark_node; |
---|
1192 | |
---|
1193 | if (IS_AGGR_TYPE (type) && (convtype & CONV_FORCE_TEMP)) |
---|
1194 | /* We need a new temporary; don't take this shortcut. */; |
---|
1195 | else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (e))) |
---|
1196 | /* Trivial conversion: cv-qualifiers do not matter on rvalues. */ |
---|
1197 | return fold (build1 (NOP_EXPR, type, e)); |
---|
1198 | |
---|
1199 | if (code == VOID_TYPE && (convtype & CONV_STATIC)) |
---|
1200 | return build1 (CONVERT_EXPR, type, e); |
---|
1201 | |
---|
1202 | #if 0 |
---|
1203 | /* This is incorrect. A truncation can't be stripped this way. |
---|
1204 | Extensions will be stripped by the use of get_unwidened. */ |
---|
1205 | if (TREE_CODE (e) == NOP_EXPR) |
---|
1206 | return convert (type, TREE_OPERAND (e, 0)); |
---|
1207 | #endif |
---|
1208 | |
---|
1209 | /* Just convert to the type of the member. */ |
---|
1210 | if (code == OFFSET_TYPE) |
---|
1211 | { |
---|
1212 | type = TREE_TYPE (type); |
---|
1213 | code = TREE_CODE (type); |
---|
1214 | } |
---|
1215 | |
---|
1216 | #if 0 |
---|
1217 | if (code == REFERENCE_TYPE) |
---|
1218 | return fold (convert_to_reference (type, e, convtype, flags, NULL_TREE)); |
---|
1219 | else if (TREE_CODE (TREE_TYPE (e)) == REFERENCE_TYPE) |
---|
1220 | e = convert_from_reference (e); |
---|
1221 | #endif |
---|
1222 | |
---|
1223 | if (TREE_CODE (e) == OFFSET_REF) |
---|
1224 | e = resolve_offset_ref (e); |
---|
1225 | |
---|
1226 | if (TREE_READONLY_DECL_P (e)) |
---|
1227 | e = decl_constant_value (e); |
---|
1228 | |
---|
1229 | if (INTEGRAL_CODE_P (code)) |
---|
1230 | { |
---|
1231 | tree intype = TREE_TYPE (e); |
---|
1232 | enum tree_code form = TREE_CODE (intype); |
---|
1233 | /* enum = enum, enum = int, enum = float are all errors. */ |
---|
1234 | if (flag_int_enum_equivalence == 0 |
---|
1235 | && TREE_CODE (type) == ENUMERAL_TYPE |
---|
1236 | && ARITHMETIC_TYPE_P (intype) |
---|
1237 | && ! (convtype & CONV_STATIC)) |
---|
1238 | { |
---|
1239 | cp_pedwarn ("conversion from `%#T' to `%#T'", intype, type); |
---|
1240 | |
---|
1241 | if (flag_pedantic_errors) |
---|
1242 | return error_mark_node; |
---|
1243 | } |
---|
1244 | if (IS_AGGR_TYPE (intype)) |
---|
1245 | { |
---|
1246 | tree rval; |
---|
1247 | rval = build_type_conversion (CONVERT_EXPR, type, e, 1); |
---|
1248 | if (rval) |
---|
1249 | return rval; |
---|
1250 | if (flags & LOOKUP_COMPLAIN) |
---|
1251 | cp_error ("`%#T' used where a `%T' was expected", intype, type); |
---|
1252 | if (flags & LOOKUP_SPECULATIVELY) |
---|
1253 | return NULL_TREE; |
---|
1254 | return error_mark_node; |
---|
1255 | } |
---|
1256 | if (code == BOOLEAN_TYPE) |
---|
1257 | return truthvalue_conversion (e); |
---|
1258 | return fold (convert_to_integer (type, e)); |
---|
1259 | } |
---|
1260 | if (code == POINTER_TYPE || code == REFERENCE_TYPE |
---|
1261 | || TYPE_PTRMEMFUNC_P (type)) |
---|
1262 | return fold (cp_convert_to_pointer (type, e)); |
---|
1263 | if (code == REAL_TYPE) |
---|
1264 | { |
---|
1265 | if (IS_AGGR_TYPE (TREE_TYPE (e))) |
---|
1266 | { |
---|
1267 | tree rval; |
---|
1268 | rval = build_type_conversion (CONVERT_EXPR, type, e, 1); |
---|
1269 | if (rval) |
---|
1270 | return rval; |
---|
1271 | else |
---|
1272 | if (flags & LOOKUP_COMPLAIN) |
---|
1273 | cp_error ("`%#T' used where a floating point value was expected", |
---|
1274 | TREE_TYPE (e)); |
---|
1275 | } |
---|
1276 | return fold (convert_to_real (type, e)); |
---|
1277 | } |
---|
1278 | |
---|
1279 | /* New C++ semantics: since assignment is now based on |
---|
1280 | memberwise copying, if the rhs type is derived from the |
---|
1281 | lhs type, then we may still do a conversion. */ |
---|
1282 | if (IS_AGGR_TYPE_CODE (code)) |
---|
1283 | { |
---|
1284 | tree dtype = TREE_TYPE (e); |
---|
1285 | tree ctor = NULL_TREE; |
---|
1286 | tree conversion = NULL_TREE; |
---|
1287 | |
---|
1288 | dtype = TYPE_MAIN_VARIANT (dtype); |
---|
1289 | |
---|
1290 | /* Conversion of object pointers or signature pointers/references |
---|
1291 | to signature pointers/references. */ |
---|
1292 | |
---|
1293 | if (TYPE_LANG_SPECIFIC (type) |
---|
1294 | && (IS_SIGNATURE_POINTER (type) || IS_SIGNATURE_REFERENCE (type))) |
---|
1295 | { |
---|
1296 | tree constructor = build_signature_pointer_constructor (type, expr); |
---|
1297 | tree sig_ty = SIGNATURE_TYPE (type); |
---|
1298 | tree sig_ptr; |
---|
1299 | |
---|
1300 | if (constructor == error_mark_node) |
---|
1301 | return error_mark_node; |
---|
1302 | |
---|
1303 | sig_ptr = get_temp_name (type, 1); |
---|
1304 | DECL_INITIAL (sig_ptr) = constructor; |
---|
1305 | CLEAR_SIGNATURE (sig_ty); |
---|
1306 | cp_finish_decl (sig_ptr, constructor, NULL_TREE, 0, 0); |
---|
1307 | SET_SIGNATURE (sig_ty); |
---|
1308 | TREE_READONLY (sig_ptr) = 1; |
---|
1309 | |
---|
1310 | return sig_ptr; |
---|
1311 | } |
---|
1312 | |
---|
1313 | /* Conversion between aggregate types. New C++ semantics allow |
---|
1314 | objects of derived type to be cast to objects of base type. |
---|
1315 | Old semantics only allowed this between pointers. |
---|
1316 | |
---|
1317 | There may be some ambiguity between using a constructor |
---|
1318 | vs. using a type conversion operator when both apply. */ |
---|
1319 | |
---|
1320 | if (IS_AGGR_TYPE (dtype) && ! DERIVED_FROM_P (type, dtype) |
---|
1321 | && TYPE_HAS_CONVERSION (dtype)) |
---|
1322 | conversion = build_type_conversion (CONVERT_EXPR, type, e, 1); |
---|
1323 | |
---|
1324 | if (conversion == error_mark_node) |
---|
1325 | { |
---|
1326 | if (flags & LOOKUP_COMPLAIN) |
---|
1327 | error ("ambiguous pointer conversion"); |
---|
1328 | return conversion; |
---|
1329 | } |
---|
1330 | |
---|
1331 | if (TYPE_HAS_CONSTRUCTOR (type)) |
---|
1332 | ctor = build_method_call (NULL_TREE, constructor_name_full (type), |
---|
1333 | build_tree_list (NULL_TREE, e), |
---|
1334 | TYPE_BINFO (type), |
---|
1335 | (flags & LOOKUP_NORMAL) | LOOKUP_SPECULATIVELY |
---|
1336 | | (convtype&CONV_NONCONVERTING ? 0 : LOOKUP_ONLYCONVERTING) |
---|
1337 | | (conversion ? LOOKUP_NO_CONVERSION : 0)); |
---|
1338 | |
---|
1339 | if (ctor == error_mark_node) |
---|
1340 | { |
---|
1341 | if (flags & LOOKUP_COMPLAIN) |
---|
1342 | cp_error ("in conversion to type `%T'", type); |
---|
1343 | if (flags & LOOKUP_SPECULATIVELY) |
---|
1344 | return NULL_TREE; |
---|
1345 | return error_mark_node; |
---|
1346 | } |
---|
1347 | |
---|
1348 | if (conversion && ctor) |
---|
1349 | { |
---|
1350 | if (flags & LOOKUP_COMPLAIN) |
---|
1351 | error ("both constructor and type conversion operator apply"); |
---|
1352 | if (flags & LOOKUP_SPECULATIVELY) |
---|
1353 | return NULL_TREE; |
---|
1354 | return error_mark_node; |
---|
1355 | } |
---|
1356 | else if (conversion) |
---|
1357 | return conversion; |
---|
1358 | else if (ctor) |
---|
1359 | { |
---|
1360 | ctor = build_cplus_new (type, ctor, 0); |
---|
1361 | return ctor; |
---|
1362 | } |
---|
1363 | } |
---|
1364 | |
---|
1365 | /* If TYPE or TREE_TYPE (E) is not on the permanent_obstack, |
---|
1366 | then the it won't be hashed and hence compare as not equal, |
---|
1367 | even when it is. */ |
---|
1368 | if (code == ARRAY_TYPE |
---|
1369 | && TREE_TYPE (TREE_TYPE (e)) == TREE_TYPE (type) |
---|
1370 | && index_type_equal (TYPE_DOMAIN (TREE_TYPE (e)), TYPE_DOMAIN (type))) |
---|
1371 | return e; |
---|
1372 | |
---|
1373 | if (flags & LOOKUP_COMPLAIN) |
---|
1374 | cp_error ("conversion from `%T' to non-scalar type `%T' requested", |
---|
1375 | TREE_TYPE (expr), type); |
---|
1376 | if (flags & LOOKUP_SPECULATIVELY) |
---|
1377 | return NULL_TREE; |
---|
1378 | return error_mark_node; |
---|
1379 | } |
---|
1380 | |
---|
1381 | /* Create an expression whose value is that of EXPR, |
---|
1382 | converted to type TYPE. The TREE_TYPE of the value |
---|
1383 | is always TYPE. This function implements all reasonable |
---|
1384 | conversions; callers should filter out those that are |
---|
1385 | not permitted by the language being compiled. */ |
---|
1386 | |
---|
1387 | tree |
---|
1388 | convert (type, expr) |
---|
1389 | tree type, expr; |
---|
1390 | { |
---|
1391 | return cp_convert (type, expr, CONV_OLD_CONVERT, LOOKUP_NORMAL); |
---|
1392 | } |
---|
1393 | |
---|
1394 | /* Like convert, except permit conversions to take place which |
---|
1395 | are not normally allowed due to access restrictions |
---|
1396 | (such as conversion from sub-type to private super-type). */ |
---|
1397 | tree |
---|
1398 | convert_force (type, expr, convtype) |
---|
1399 | tree type; |
---|
1400 | tree expr; |
---|
1401 | int convtype; |
---|
1402 | { |
---|
1403 | register tree e = expr; |
---|
1404 | register enum tree_code code = TREE_CODE (type); |
---|
1405 | |
---|
1406 | if (code == REFERENCE_TYPE) |
---|
1407 | return fold (convert_to_reference (type, e, CONV_C_CAST, LOOKUP_COMPLAIN, |
---|
1408 | NULL_TREE)); |
---|
1409 | else if (TREE_CODE (TREE_TYPE (e)) == REFERENCE_TYPE) |
---|
1410 | e = convert_from_reference (e); |
---|
1411 | |
---|
1412 | if (code == POINTER_TYPE) |
---|
1413 | return fold (convert_to_pointer_force (type, e)); |
---|
1414 | |
---|
1415 | /* From typeck.c convert_for_assignment */ |
---|
1416 | if (((TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE && TREE_CODE (e) == ADDR_EXPR |
---|
1417 | && TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE |
---|
1418 | && TREE_CODE (TREE_TYPE (TREE_TYPE (e))) == METHOD_TYPE) |
---|
1419 | || integer_zerop (e) |
---|
1420 | || TYPE_PTRMEMFUNC_P (TREE_TYPE (e))) |
---|
1421 | && TYPE_PTRMEMFUNC_P (type)) |
---|
1422 | { |
---|
1423 | /* compatible pointer to member functions. */ |
---|
1424 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), e, 1); |
---|
1425 | } |
---|
1426 | |
---|
1427 | return cp_convert (type, e, CONV_C_CAST|convtype, LOOKUP_NORMAL); |
---|
1428 | } |
---|
1429 | |
---|
1430 | /* Subroutine of build_type_conversion. */ |
---|
1431 | static tree |
---|
1432 | build_type_conversion_1 (xtype, basetype, expr, typename, for_sure) |
---|
1433 | tree xtype, basetype; |
---|
1434 | tree expr; |
---|
1435 | tree typename; |
---|
1436 | int for_sure; |
---|
1437 | { |
---|
1438 | tree rval; |
---|
1439 | int flags; |
---|
1440 | |
---|
1441 | if (for_sure == 0) |
---|
1442 | flags = LOOKUP_PROTECT|LOOKUP_ONLYCONVERTING; |
---|
1443 | else |
---|
1444 | flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING; |
---|
1445 | |
---|
1446 | rval = build_method_call (expr, typename, NULL_TREE, NULL_TREE, flags); |
---|
1447 | if (rval == error_mark_node) |
---|
1448 | { |
---|
1449 | if (for_sure == 0) |
---|
1450 | return NULL_TREE; |
---|
1451 | return error_mark_node; |
---|
1452 | } |
---|
1453 | |
---|
1454 | if (IS_AGGR_TYPE (TREE_TYPE (rval))) |
---|
1455 | return rval; |
---|
1456 | |
---|
1457 | if (warn_cast_qual |
---|
1458 | && TREE_TYPE (xtype) |
---|
1459 | && (TREE_READONLY (TREE_TYPE (TREE_TYPE (rval))) |
---|
1460 | > TREE_READONLY (TREE_TYPE (xtype)))) |
---|
1461 | warning ("user-defined conversion casting away `const'"); |
---|
1462 | return convert (xtype, rval); |
---|
1463 | } |
---|
1464 | |
---|
1465 | /* Convert an aggregate EXPR to type XTYPE. If a conversion |
---|
1466 | exists, return the attempted conversion. This may |
---|
1467 | return ERROR_MARK_NODE if the conversion is not |
---|
1468 | allowed (references private members, etc). |
---|
1469 | If no conversion exists, NULL_TREE is returned. |
---|
1470 | |
---|
1471 | If (FOR_SURE & 1) is non-zero, then we allow this type conversion |
---|
1472 | to take place immediately. Otherwise, we build a SAVE_EXPR |
---|
1473 | which can be evaluated if the results are ever needed. |
---|
1474 | |
---|
1475 | Changes to this functions should be mirrored in user_harshness. |
---|
1476 | |
---|
1477 | FIXME: Ambiguity checking is wrong. Should choose one by the implicit |
---|
1478 | object parameter, or by the second standard conversion sequence if |
---|
1479 | that doesn't do it. This will probably wait for an overloading rewrite. |
---|
1480 | (jason 8/9/95) */ |
---|
1481 | |
---|
1482 | tree |
---|
1483 | build_type_conversion (code, xtype, expr, for_sure) |
---|
1484 | enum tree_code code; |
---|
1485 | tree xtype, expr; |
---|
1486 | int for_sure; |
---|
1487 | { |
---|
1488 | /* C++: check to see if we can convert this aggregate type |
---|
1489 | into the required type. */ |
---|
1490 | tree basetype; |
---|
1491 | tree conv; |
---|
1492 | tree winner = NULL_TREE; |
---|
1493 | |
---|
1494 | if (expr == error_mark_node) |
---|
1495 | return error_mark_node; |
---|
1496 | |
---|
1497 | basetype = TREE_TYPE (expr); |
---|
1498 | if (TREE_CODE (basetype) == REFERENCE_TYPE) |
---|
1499 | basetype = TREE_TYPE (basetype); |
---|
1500 | |
---|
1501 | basetype = TYPE_MAIN_VARIANT (basetype); |
---|
1502 | if (! TYPE_LANG_SPECIFIC (basetype) || ! TYPE_HAS_CONVERSION (basetype)) |
---|
1503 | return NULL_TREE; |
---|
1504 | |
---|
1505 | /* Do we have an exact match? */ |
---|
1506 | { |
---|
1507 | tree typename = build_typename_overload (xtype); |
---|
1508 | if (lookup_fnfields (TYPE_BINFO (basetype), typename, 0)) |
---|
1509 | return build_type_conversion_1 (xtype, basetype, expr, typename, |
---|
1510 | for_sure); |
---|
1511 | } |
---|
1512 | |
---|
1513 | /* Nope; try looking for others. */ |
---|
1514 | for (conv = lookup_conversions (basetype); conv; conv = TREE_CHAIN (conv)) |
---|
1515 | { |
---|
1516 | if (winner && TREE_PURPOSE (winner) == TREE_PURPOSE (conv)) |
---|
1517 | continue; |
---|
1518 | |
---|
1519 | if (can_convert (xtype, TREE_VALUE (conv))) |
---|
1520 | { |
---|
1521 | if (winner) |
---|
1522 | { |
---|
1523 | if (for_sure) |
---|
1524 | { |
---|
1525 | cp_error ("ambiguous conversion from `%T' to `%T'", basetype, |
---|
1526 | xtype); |
---|
1527 | cp_error (" candidate conversions include `%T' and `%T'", |
---|
1528 | TREE_VALUE (winner), TREE_VALUE (conv)); |
---|
1529 | } |
---|
1530 | return NULL_TREE; |
---|
1531 | } |
---|
1532 | else |
---|
1533 | winner = conv; |
---|
1534 | } |
---|
1535 | } |
---|
1536 | |
---|
1537 | if (winner) |
---|
1538 | return build_type_conversion_1 (xtype, basetype, expr, |
---|
1539 | TREE_PURPOSE (winner), for_sure); |
---|
1540 | |
---|
1541 | return NULL_TREE; |
---|
1542 | } |
---|
1543 | |
---|
1544 | /* Convert the given EXPR to one of a group of types suitable for use in an |
---|
1545 | expression. DESIRES is a combination of various WANT_* flags (q.v.) |
---|
1546 | which indicates which types are suitable. If COMPLAIN is 1, complain |
---|
1547 | about ambiguity; otherwise, the caller will deal with it. */ |
---|
1548 | |
---|
1549 | tree |
---|
1550 | build_expr_type_conversion (desires, expr, complain) |
---|
1551 | int desires; |
---|
1552 | tree expr; |
---|
1553 | int complain; |
---|
1554 | { |
---|
1555 | tree basetype = TREE_TYPE (expr); |
---|
1556 | tree conv; |
---|
1557 | tree winner = NULL_TREE; |
---|
1558 | |
---|
1559 | if (TREE_CODE (basetype) == OFFSET_TYPE) |
---|
1560 | expr = resolve_offset_ref (expr); |
---|
1561 | expr = convert_from_reference (expr); |
---|
1562 | basetype = TREE_TYPE (expr); |
---|
1563 | |
---|
1564 | if (! IS_AGGR_TYPE (basetype)) |
---|
1565 | switch (TREE_CODE (basetype)) |
---|
1566 | { |
---|
1567 | case INTEGER_TYPE: |
---|
1568 | if ((desires & WANT_NULL) && TREE_CODE (expr) == INTEGER_CST |
---|
1569 | && integer_zerop (expr)) |
---|
1570 | return expr; |
---|
1571 | /* else fall through... */ |
---|
1572 | |
---|
1573 | case BOOLEAN_TYPE: |
---|
1574 | return (desires & WANT_INT) ? expr : NULL_TREE; |
---|
1575 | case ENUMERAL_TYPE: |
---|
1576 | return (desires & WANT_ENUM) ? expr : NULL_TREE; |
---|
1577 | case REAL_TYPE: |
---|
1578 | return (desires & WANT_FLOAT) ? expr : NULL_TREE; |
---|
1579 | case POINTER_TYPE: |
---|
1580 | return (desires & WANT_POINTER) ? expr : NULL_TREE; |
---|
1581 | |
---|
1582 | case FUNCTION_TYPE: |
---|
1583 | case ARRAY_TYPE: |
---|
1584 | return (desires & WANT_POINTER) ? default_conversion (expr) |
---|
1585 | : NULL_TREE; |
---|
1586 | default: |
---|
1587 | return NULL_TREE; |
---|
1588 | } |
---|
1589 | |
---|
1590 | if (! TYPE_HAS_CONVERSION (basetype)) |
---|
1591 | return NULL_TREE; |
---|
1592 | |
---|
1593 | for (conv = lookup_conversions (basetype); conv; conv = TREE_CHAIN (conv)) |
---|
1594 | { |
---|
1595 | int win = 0; |
---|
1596 | tree candidate; |
---|
1597 | |
---|
1598 | if (winner && TREE_PURPOSE (winner) == TREE_PURPOSE (conv)) |
---|
1599 | continue; |
---|
1600 | |
---|
1601 | candidate = TREE_VALUE (conv); |
---|
1602 | if (TREE_CODE (candidate) == REFERENCE_TYPE) |
---|
1603 | candidate = TREE_TYPE (candidate); |
---|
1604 | |
---|
1605 | switch (TREE_CODE (candidate)) |
---|
1606 | { |
---|
1607 | case BOOLEAN_TYPE: |
---|
1608 | case INTEGER_TYPE: |
---|
1609 | win = (desires & WANT_INT); break; |
---|
1610 | case ENUMERAL_TYPE: |
---|
1611 | win = (desires & WANT_ENUM); break; |
---|
1612 | case REAL_TYPE: |
---|
1613 | win = (desires & WANT_FLOAT); break; |
---|
1614 | case POINTER_TYPE: |
---|
1615 | win = (desires & WANT_POINTER); break; |
---|
1616 | } |
---|
1617 | |
---|
1618 | if (win) |
---|
1619 | { |
---|
1620 | if (winner) |
---|
1621 | { |
---|
1622 | if (complain) |
---|
1623 | { |
---|
1624 | cp_error ("ambiguous default type conversion from `%T'", |
---|
1625 | basetype); |
---|
1626 | cp_error (" candidate conversions include `%T' and `%T'", |
---|
1627 | TREE_VALUE (winner), TREE_VALUE (conv)); |
---|
1628 | } |
---|
1629 | return error_mark_node; |
---|
1630 | } |
---|
1631 | else |
---|
1632 | winner = conv; |
---|
1633 | } |
---|
1634 | } |
---|
1635 | |
---|
1636 | if (winner) |
---|
1637 | return build_type_conversion_1 (TREE_VALUE (winner), basetype, expr, |
---|
1638 | TREE_PURPOSE (winner), 1); |
---|
1639 | |
---|
1640 | return NULL_TREE; |
---|
1641 | } |
---|
1642 | |
---|
1643 | /* Must convert two aggregate types to non-aggregate type. |
---|
1644 | Attempts to find a non-ambiguous, "best" type conversion. |
---|
1645 | |
---|
1646 | Return 1 on success, 0 on failure. |
---|
1647 | |
---|
1648 | @@ What are the real semantics of this supposed to be??? */ |
---|
1649 | int |
---|
1650 | build_default_binary_type_conversion (code, arg1, arg2) |
---|
1651 | enum tree_code code; |
---|
1652 | tree *arg1, *arg2; |
---|
1653 | { |
---|
1654 | switch (code) |
---|
1655 | { |
---|
1656 | case MULT_EXPR: |
---|
1657 | case TRUNC_DIV_EXPR: |
---|
1658 | case CEIL_DIV_EXPR: |
---|
1659 | case FLOOR_DIV_EXPR: |
---|
1660 | case ROUND_DIV_EXPR: |
---|
1661 | case EXACT_DIV_EXPR: |
---|
1662 | *arg1 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg1, 0); |
---|
1663 | *arg2 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg2, 0); |
---|
1664 | break; |
---|
1665 | |
---|
1666 | case TRUNC_MOD_EXPR: |
---|
1667 | case FLOOR_MOD_EXPR: |
---|
1668 | case LSHIFT_EXPR: |
---|
1669 | case RSHIFT_EXPR: |
---|
1670 | case BIT_AND_EXPR: |
---|
1671 | case BIT_XOR_EXPR: |
---|
1672 | case BIT_IOR_EXPR: |
---|
1673 | *arg1 = build_expr_type_conversion (WANT_INT | WANT_ENUM, *arg1, 0); |
---|
1674 | *arg2 = build_expr_type_conversion (WANT_INT | WANT_ENUM, *arg2, 0); |
---|
1675 | break; |
---|
1676 | |
---|
1677 | case PLUS_EXPR: |
---|
1678 | { |
---|
1679 | tree a1, a2, p1, p2; |
---|
1680 | int wins; |
---|
1681 | |
---|
1682 | a1 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg1, 0); |
---|
1683 | a2 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg2, 0); |
---|
1684 | p1 = build_expr_type_conversion (WANT_POINTER, *arg1, 0); |
---|
1685 | p2 = build_expr_type_conversion (WANT_POINTER, *arg2, 0); |
---|
1686 | |
---|
1687 | wins = (a1 && a2) + (a1 && p2) + (p1 && a2); |
---|
1688 | |
---|
1689 | if (wins > 1) |
---|
1690 | error ("ambiguous default type conversion for `operator +'"); |
---|
1691 | |
---|
1692 | if (a1 && a2) |
---|
1693 | *arg1 = a1, *arg2 = a2; |
---|
1694 | else if (a1 && p2) |
---|
1695 | *arg1 = a1, *arg2 = p2; |
---|
1696 | else |
---|
1697 | *arg1 = p1, *arg2 = a2; |
---|
1698 | break; |
---|
1699 | } |
---|
1700 | |
---|
1701 | case MINUS_EXPR: |
---|
1702 | { |
---|
1703 | tree a1, a2, p1, p2; |
---|
1704 | int wins; |
---|
1705 | |
---|
1706 | a1 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg1, 0); |
---|
1707 | a2 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg2, 0); |
---|
1708 | p1 = build_expr_type_conversion (WANT_POINTER, *arg1, 0); |
---|
1709 | p2 = build_expr_type_conversion (WANT_POINTER, *arg2, 0); |
---|
1710 | |
---|
1711 | wins = (a1 && a2) + (p1 && p2) + (p1 && a2); |
---|
1712 | |
---|
1713 | if (wins > 1) |
---|
1714 | error ("ambiguous default type conversion for `operator -'"); |
---|
1715 | |
---|
1716 | if (a1 && a2) |
---|
1717 | *arg1 = a1, *arg2 = a2; |
---|
1718 | else if (p1 && p2) |
---|
1719 | *arg1 = p1, *arg2 = p2; |
---|
1720 | else |
---|
1721 | *arg1 = p1, *arg2 = a2; |
---|
1722 | break; |
---|
1723 | } |
---|
1724 | |
---|
1725 | case GT_EXPR: |
---|
1726 | case LT_EXPR: |
---|
1727 | case GE_EXPR: |
---|
1728 | case LE_EXPR: |
---|
1729 | case EQ_EXPR: |
---|
1730 | case NE_EXPR: |
---|
1731 | { |
---|
1732 | tree a1, a2, p1, p2; |
---|
1733 | int wins; |
---|
1734 | |
---|
1735 | a1 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg1, 0); |
---|
1736 | a2 = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, *arg2, 0); |
---|
1737 | p1 = build_expr_type_conversion (WANT_POINTER | WANT_NULL, *arg1, 0); |
---|
1738 | p2 = build_expr_type_conversion (WANT_POINTER | WANT_NULL, *arg2, 0); |
---|
1739 | |
---|
1740 | wins = (a1 && a2) + (p1 && p2); |
---|
1741 | |
---|
1742 | if (wins > 1) |
---|
1743 | cp_error ("ambiguous default type conversion for `%O'", code); |
---|
1744 | |
---|
1745 | if (a1 && a2) |
---|
1746 | *arg1 = a1, *arg2 = a2; |
---|
1747 | else |
---|
1748 | *arg1 = p1, *arg2 = p2; |
---|
1749 | break; |
---|
1750 | } |
---|
1751 | |
---|
1752 | case TRUTH_ANDIF_EXPR: |
---|
1753 | case TRUTH_ORIF_EXPR: |
---|
1754 | *arg1 = convert (boolean_type_node, *arg1); |
---|
1755 | *arg2 = convert (boolean_type_node, *arg2); |
---|
1756 | break; |
---|
1757 | |
---|
1758 | default: |
---|
1759 | *arg1 = NULL_TREE; |
---|
1760 | *arg2 = NULL_TREE; |
---|
1761 | } |
---|
1762 | |
---|
1763 | if (*arg1 == error_mark_node || *arg2 == error_mark_node) |
---|
1764 | cp_error ("ambiguous default type conversion for `%O'", code); |
---|
1765 | |
---|
1766 | if (*arg1 && *arg2) |
---|
1767 | return 1; |
---|
1768 | |
---|
1769 | return 0; |
---|
1770 | } |
---|
1771 | |
---|
1772 | /* Implements integral promotion (4.1) and float->double promotion. */ |
---|
1773 | tree |
---|
1774 | type_promotes_to (type) |
---|
1775 | tree type; |
---|
1776 | { |
---|
1777 | int constp, volatilep; |
---|
1778 | |
---|
1779 | if (type == error_mark_node) |
---|
1780 | return error_mark_node; |
---|
1781 | |
---|
1782 | constp = TYPE_READONLY (type); |
---|
1783 | volatilep = TYPE_VOLATILE (type); |
---|
1784 | type = TYPE_MAIN_VARIANT (type); |
---|
1785 | |
---|
1786 | /* bool always promotes to int (not unsigned), even if it's the same |
---|
1787 | size. */ |
---|
1788 | if (type == boolean_type_node) |
---|
1789 | type = integer_type_node; |
---|
1790 | |
---|
1791 | /* Normally convert enums to int, but convert wide enums to something |
---|
1792 | wider. */ |
---|
1793 | else if (TREE_CODE (type) == ENUMERAL_TYPE |
---|
1794 | || type == wchar_type_node) |
---|
1795 | { |
---|
1796 | int precision = MAX (TYPE_PRECISION (type), |
---|
1797 | TYPE_PRECISION (integer_type_node)); |
---|
1798 | tree totype = type_for_size (precision, 0); |
---|
1799 | if (TREE_UNSIGNED (type) |
---|
1800 | && ! int_fits_type_p (TYPE_MAX_VALUE (type), totype)) |
---|
1801 | type = type_for_size (precision, 1); |
---|
1802 | else |
---|
1803 | type = totype; |
---|
1804 | } |
---|
1805 | else if (C_PROMOTING_INTEGER_TYPE_P (type)) |
---|
1806 | { |
---|
1807 | /* Traditionally, unsignedness is preserved in default promotions. |
---|
1808 | Otherwise, retain unsignedness if really not getting bigger. */ |
---|
1809 | if (TREE_UNSIGNED (type) |
---|
1810 | && (flag_traditional |
---|
1811 | || TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))) |
---|
1812 | type = unsigned_type_node; |
---|
1813 | else |
---|
1814 | type = integer_type_node; |
---|
1815 | } |
---|
1816 | else if (type == float_type_node) |
---|
1817 | type = double_type_node; |
---|
1818 | |
---|
1819 | return cp_build_type_variant (type, constp, volatilep); |
---|
1820 | } |
---|