1 | .\" Copyright (c) 2011 Kai Wang |
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2 | .\" All rights reserved. |
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3 | .\" |
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5 | .\" modification, are permitted provided that the following conditions |
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6 | .\" are met: |
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7 | .\" 1. Redistributions of source code must retain the above copyright |
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8 | .\" notice, this list of conditions and the following disclaimer. |
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9 | .\" 2. Redistributions in binary form must reproduce the above copyright |
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11 | .\" documentation and/or other materials provided with the distribution. |
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13 | .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
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14 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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15 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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16 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
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23 | .\" SUCH DAMAGE. |
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25 | .\" $Id: dwarf_get_weaks.3 2071 2011-10-27 03:20:00Z jkoshy $ |
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26 | .\" |
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27 | .Dd April 10, 2011 |
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28 | .Os |
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29 | .Dt DWARF_GET_WEAKS 3 |
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30 | .Sh NAME |
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31 | .Nm dwarf_get_weaks , |
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32 | .Nm dwarf_weak_cu_offset , |
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33 | .Nm dwarf_weak_die_offset , |
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34 | .Nm dwarf_weak_name_offsets , |
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35 | .Nm dwarf_weakname |
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36 | .Nd retrieve information about weak symbols |
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37 | .Sh LIBRARY |
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38 | .Lb libdwarf |
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39 | .Sh SYNOPSIS |
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40 | .In libdwarf.h |
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41 | .Ft int |
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42 | .Fo dwarf_get_weaks |
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43 | .Fa "Dwarf_Debug dbg" |
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44 | .Fa "Dwarf_Weak **weaks" |
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45 | .Fa "Dwarf_Signed *nweaks" |
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46 | .Fa "Dwarf_Error *err" |
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47 | .Fc |
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48 | .Ft int |
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49 | .Fo dwarf_weak_cu_offset |
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50 | .Fa "Dwarf_Weak weak" |
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51 | .Fa "Dwarf_Off *cu_offset" |
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52 | .Fa "Dwarf_Error *err" |
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53 | .Fc |
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54 | .Ft int |
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55 | .Fo dwarf_weak_die_offset |
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56 | .Fa "Dwarf_Weak weak" |
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57 | .Fa "Dwarf_Off *die_offset" |
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58 | .Fa "Dwarf_Error *err" |
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59 | .Fc |
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60 | .Ft int |
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61 | .Fo dwarf_weak_name_offsets |
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62 | .Fa "Dwarf_Weak weak" |
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63 | .Fa "char **name" |
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64 | .Fa "Dwarf_Off *die_offset" |
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65 | .Fa "Dwarf_Off *cu_die_offset" |
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66 | .Fa "Dwarf_Error *err" |
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67 | .Fc |
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68 | .Ft int |
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69 | .Fo dwarf_weakname |
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70 | .Fa "Dwarf_Weak weak" |
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71 | .Fa "char **name" |
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72 | .Fa "Dwarf_Error *err" |
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73 | .Fc |
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74 | .Sh DESCRIPTION |
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75 | These functions retrieve information about weak symbols from the |
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76 | lookup tables in the (SGI-specific) |
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77 | .Dq ".debug_weaknames" |
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78 | section. |
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79 | Information about weak symbols is returned using opaque descriptors |
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80 | of type |
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81 | .Vt Dwarf_Weak . |
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82 | Applications need to use the functions described below to retrieve |
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83 | the name and offset information contained in these descriptors. |
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84 | .Pp |
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85 | Function |
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86 | .Fn dwarf_get_weaks |
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87 | retrieves descriptors for all the weak symbols associated with the |
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88 | DWARF debug context specified by argument |
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89 | .Ar dbg . |
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90 | The argument |
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91 | .Ar weaks |
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92 | should point to a location that will be set to a pointer to an array |
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93 | of |
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94 | .Vt Dwarf_Weak |
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95 | descriptors. |
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96 | The argument |
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97 | .Ar nweaks |
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98 | should point to a location that will be set to the number of |
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99 | descriptors returned. |
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100 | .Pp |
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101 | Function |
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102 | .Fn dwarf_weak_cu_offset |
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103 | returns the offset, relative to the |
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104 | .Dq ".debug_info" |
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105 | section, of the compilation unit that contains the debugging |
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106 | information entry associated with the argument |
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107 | .Ar weak . |
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108 | Argument |
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109 | .Ar cu_offset |
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110 | should point to a location that will hold the returned offset. |
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111 | .Pp |
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112 | Function |
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113 | .Fn dwarf_weak_die_offset |
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114 | retrieves the offset, relative to the |
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115 | .Dq ".debug_info" |
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116 | section, of the debugging information entry associated with the |
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117 | argument |
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118 | .Ar weak , |
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119 | and stores it into the location pointed to by the argument |
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120 | .Ar die_offset . |
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121 | .Pp |
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122 | Function |
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123 | .Fn dwarf_weak_name_offsets |
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124 | retrieves the name and offsets for the debugging information |
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125 | entry for argument |
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126 | .Ar weak . |
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127 | Argument |
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128 | .Ar name |
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129 | should point to a location which will be set to a pointer to a |
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130 | NUL-terminated string containing the name of the associated debugging |
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131 | information entry. |
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132 | Argument |
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133 | .Ar die_offset |
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134 | should point to a location which will be set to the offset, relative |
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135 | to the |
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136 | .Dq ".debug_info" |
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137 | section, of the associated debugging information entry. |
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138 | Argument |
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139 | .Ar cu_die_offset |
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140 | should point to a location which will be set to the |
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141 | offset, relative to the |
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142 | .Dq ".debug_info" |
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143 | section, of the first debugging information entry in the compilation |
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144 | unit associated with argument |
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145 | .Ar weak . |
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146 | .Pp |
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147 | Function |
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148 | .Fn dwarf_weakname |
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149 | sets the location pointed to by argument |
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150 | .Ar name |
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151 | to a pointer to a NUL-terminated string holding the name of the |
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152 | debugging information entry associated with the argument |
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153 | .Ar weak . |
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154 | .Ss Memory Management |
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155 | The memory area used for the array of |
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156 | .Vt Dwarf_Weak |
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157 | descriptors returned in argument |
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158 | .Ar weaks |
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159 | by function |
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160 | .Fn dwarf_get_weaks |
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161 | is owned by the |
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162 | .Lb libdwarf . |
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163 | Application code should not attempt to directly free this pointer. |
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164 | Portable code should instead use the function |
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165 | .Xr dwarf_weaks_dealloc 3 |
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166 | to indicate that the memory area may be freed. |
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167 | .Pp |
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168 | The memory area used for the string returned in the |
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169 | .Ar name |
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170 | argument to functions |
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171 | .Fn dwarf_weak_name_offsets |
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172 | and |
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173 | .Fn dwarf_weakname |
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174 | is owned by the |
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175 | .Lb libdwarf . |
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176 | Portable code should indicate that the memory area can |
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177 | be freed using the |
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178 | .Xr dwarf_dealloc 3 |
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179 | function. |
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180 | .Ss Error Returns |
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181 | If argument |
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182 | .Ar err |
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183 | is not NULL, these functions will use it to store error information, |
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184 | in case of an error. |
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185 | .Sh RETURN VALUES |
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186 | On success, these functions returns |
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187 | .Dv DW_DLV_OK . |
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188 | In case of an error, they return |
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189 | .Dv DW_DLV_ERROR |
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190 | and set the argument |
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191 | .Ar err . |
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192 | .Sh ERRORS |
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193 | These functions may fail with the following errors: |
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194 | .Bl -tag -width ".Bq Er DW_DLE_ARGUMENT" |
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195 | .It Bq Er DW_DLE_ARGUMENT |
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196 | One of the arguments |
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197 | .Va cu_die_offset , |
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198 | .Va cu_offset , |
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199 | .Va dbg , |
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200 | .Va die_offset , |
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201 | .Va weak , |
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202 | .Va weaks , |
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203 | .Va name , |
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204 | or |
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205 | .Va nweaks |
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206 | was NULL. |
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207 | .It Bq Er DW_DLE_NO_ENTRY |
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208 | The DWARF debugging context referenced by argument |
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209 | .Ar dbg |
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210 | did not contain information about weak symbols. |
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211 | .El |
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212 | .Sh SEE ALSO |
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213 | .Xr dwarf 3 , |
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214 | .Xr dwarf_get_cu_die_offset_given_cu_header_offset 3 , |
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215 | .Xr dwarf_weaks_dealloc 3 |
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