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5191 | serge | 1 | /* plugin-api.h -- External linker plugin API. */ |
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6324 | serge | 3 | /* Copyright (C) 2009-2015 Free Software Foundation, Inc. |
5191 | serge | 4 | Written by Cary Coutant |
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6 | This file is part of binutils. |
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7 | |||
8 | This program is free software; you can redistribute it and/or modify |
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9 | it under the terms of the GNU General Public License as published by |
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10 | the Free Software Foundation; either version 3 of the License, or |
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11 | (at your option) any later version. |
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12 | |||
13 | This program is distributed in the hope that it will be useful, |
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14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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16 | GNU General Public License for more details. |
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17 | |||
18 | You should have received a copy of the GNU General Public License |
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19 | along with this program; if not, write to the Free Software |
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20 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
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21 | MA 02110-1301, USA. */ |
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22 | |||
23 | /* This file defines the interface for writing a linker plugin, which is |
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24 | described at < http://gcc.gnu.org/wiki/whopr/driver >. */ |
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25 | |||
26 | #ifndef PLUGIN_API_H |
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27 | #define PLUGIN_API_H |
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28 | |||
29 | #ifdef HAVE_STDINT_H |
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30 | #include |
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31 | #elif defined(HAVE_INTTYPES_H) |
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32 | #include |
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33 | #endif |
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34 | #include |
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35 | #if !defined(HAVE_STDINT_H) && !defined(HAVE_INTTYPES_H) && \ |
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36 | !defined(UINT64_MAX) && !defined(uint64_t) |
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37 | #error can not find uint64_t type |
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38 | #endif |
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39 | |||
40 | #ifdef __cplusplus |
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41 | extern "C" |
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42 | { |
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43 | #endif |
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44 | |||
45 | /* Status code returned by most API routines. */ |
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46 | |||
47 | enum ld_plugin_status |
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48 | { |
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49 | LDPS_OK = 0, |
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50 | LDPS_NO_SYMS, /* Attempt to get symbols that haven't been added. */ |
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51 | LDPS_BAD_HANDLE, /* No claimed object associated with given handle. */ |
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52 | LDPS_ERR |
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53 | /* Additional Error codes TBD. */ |
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54 | }; |
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55 | |||
56 | /* The version of the API specification. */ |
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57 | |||
58 | enum ld_plugin_api_version |
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59 | { |
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60 | LD_PLUGIN_API_VERSION = 1 |
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61 | }; |
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62 | |||
63 | /* The type of output file being generated by the linker. */ |
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64 | |||
65 | enum ld_plugin_output_file_type |
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66 | { |
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67 | LDPO_REL, |
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68 | LDPO_EXEC, |
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69 | LDPO_DYN, |
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70 | LDPO_PIE |
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71 | }; |
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72 | |||
73 | /* An input file managed by the plugin library. */ |
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74 | |||
75 | struct ld_plugin_input_file |
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76 | { |
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77 | const char *name; |
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78 | int fd; |
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79 | off_t offset; |
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80 | off_t filesize; |
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81 | void *handle; |
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82 | }; |
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83 | |||
84 | /* A symbol belonging to an input file managed by the plugin library. */ |
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85 | |||
86 | struct ld_plugin_symbol |
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87 | { |
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88 | char *name; |
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89 | char *version; |
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90 | int def; |
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91 | int visibility; |
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92 | uint64_t size; |
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93 | char *comdat_key; |
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94 | int resolution; |
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95 | }; |
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96 | |||
97 | /* An object's section. */ |
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98 | |||
99 | struct ld_plugin_section |
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100 | { |
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101 | const void* handle; |
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102 | unsigned int shndx; |
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103 | }; |
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104 | |||
105 | /* Whether the symbol is a definition, reference, or common, weak or not. */ |
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106 | |||
107 | enum ld_plugin_symbol_kind |
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108 | { |
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109 | LDPK_DEF, |
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110 | LDPK_WEAKDEF, |
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111 | LDPK_UNDEF, |
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112 | LDPK_WEAKUNDEF, |
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113 | LDPK_COMMON |
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114 | }; |
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115 | |||
116 | /* The visibility of the symbol. */ |
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117 | |||
118 | enum ld_plugin_symbol_visibility |
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119 | { |
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120 | LDPV_DEFAULT, |
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121 | LDPV_PROTECTED, |
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122 | LDPV_INTERNAL, |
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123 | LDPV_HIDDEN |
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124 | }; |
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125 | |||
126 | /* How a symbol is resolved. */ |
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127 | |||
128 | enum ld_plugin_symbol_resolution |
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129 | { |
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130 | LDPR_UNKNOWN = 0, |
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131 | |||
132 | /* Symbol is still undefined at this point. */ |
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133 | LDPR_UNDEF, |
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134 | |||
135 | /* This is the prevailing definition of the symbol, with references from |
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136 | regular object code. */ |
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137 | LDPR_PREVAILING_DEF, |
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138 | |||
139 | /* This is the prevailing definition of the symbol, with no |
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140 | references from regular objects. It is only referenced from IR |
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141 | code. */ |
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142 | LDPR_PREVAILING_DEF_IRONLY, |
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143 | |||
144 | /* This definition was pre-empted by a definition in a regular |
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145 | object file. */ |
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146 | LDPR_PREEMPTED_REG, |
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147 | |||
148 | /* This definition was pre-empted by a definition in another IR file. */ |
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149 | LDPR_PREEMPTED_IR, |
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150 | |||
151 | /* This symbol was resolved by a definition in another IR file. */ |
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152 | LDPR_RESOLVED_IR, |
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153 | |||
154 | /* This symbol was resolved by a definition in a regular object |
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155 | linked into the main executable. */ |
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156 | LDPR_RESOLVED_EXEC, |
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157 | |||
158 | /* This symbol was resolved by a definition in a shared object. */ |
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159 | LDPR_RESOLVED_DYN, |
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160 | |||
161 | /* This is the prevailing definition of the symbol, with no |
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162 | references from regular objects. It is only referenced from IR |
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163 | code, but the symbol is exported and may be referenced from |
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164 | a dynamic object (not seen at link time). */ |
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165 | LDPR_PREVAILING_DEF_IRONLY_EXP |
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166 | }; |
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167 | |||
168 | /* The plugin library's "claim file" handler. */ |
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169 | |||
170 | typedef |
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171 | enum ld_plugin_status |
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172 | (*ld_plugin_claim_file_handler) ( |
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173 | const struct ld_plugin_input_file *file, int *claimed); |
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174 | |||
175 | /* The plugin library's "all symbols read" handler. */ |
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176 | |||
177 | typedef |
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178 | enum ld_plugin_status |
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179 | (*ld_plugin_all_symbols_read_handler) (void); |
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180 | |||
181 | /* The plugin library's cleanup handler. */ |
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182 | |||
183 | typedef |
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184 | enum ld_plugin_status |
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185 | (*ld_plugin_cleanup_handler) (void); |
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186 | |||
187 | /* The linker's interface for registering the "claim file" handler. */ |
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188 | |||
189 | typedef |
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190 | enum ld_plugin_status |
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191 | (*ld_plugin_register_claim_file) (ld_plugin_claim_file_handler handler); |
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192 | |||
193 | /* The linker's interface for registering the "all symbols read" handler. */ |
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194 | |||
195 | typedef |
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196 | enum ld_plugin_status |
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197 | (*ld_plugin_register_all_symbols_read) ( |
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198 | ld_plugin_all_symbols_read_handler handler); |
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199 | |||
200 | /* The linker's interface for registering the cleanup handler. */ |
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201 | |||
202 | typedef |
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203 | enum ld_plugin_status |
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204 | (*ld_plugin_register_cleanup) (ld_plugin_cleanup_handler handler); |
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205 | |||
206 | /* The linker's interface for adding symbols from a claimed input file. */ |
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207 | |||
208 | typedef |
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209 | enum ld_plugin_status |
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210 | (*ld_plugin_add_symbols) (void *handle, int nsyms, |
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211 | const struct ld_plugin_symbol *syms); |
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212 | |||
213 | /* The linker's interface for getting the input file information with |
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214 | an open (possibly re-opened) file descriptor. */ |
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215 | |||
216 | typedef |
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217 | enum ld_plugin_status |
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218 | (*ld_plugin_get_input_file) (const void *handle, |
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219 | struct ld_plugin_input_file *file); |
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220 | |||
221 | typedef |
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222 | enum ld_plugin_status |
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223 | (*ld_plugin_get_view) (const void *handle, const void **viewp); |
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224 | |||
225 | /* The linker's interface for releasing the input file. */ |
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226 | |||
227 | typedef |
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228 | enum ld_plugin_status |
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229 | (*ld_plugin_release_input_file) (const void *handle); |
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230 | |||
231 | /* The linker's interface for retrieving symbol resolution information. */ |
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232 | |||
233 | typedef |
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234 | enum ld_plugin_status |
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235 | (*ld_plugin_get_symbols) (const void *handle, int nsyms, |
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236 | struct ld_plugin_symbol *syms); |
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237 | |||
238 | /* The linker's interface for adding a compiled input file. */ |
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239 | |||
240 | typedef |
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241 | enum ld_plugin_status |
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242 | (*ld_plugin_add_input_file) (const char *pathname); |
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243 | |||
244 | /* The linker's interface for adding a library that should be searched. */ |
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245 | |||
246 | typedef |
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247 | enum ld_plugin_status |
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248 | (*ld_plugin_add_input_library) (const char *libname); |
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249 | |||
250 | /* The linker's interface for adding a library path that should be searched. */ |
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251 | |||
252 | typedef |
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253 | enum ld_plugin_status |
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254 | (*ld_plugin_set_extra_library_path) (const char *path); |
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255 | |||
256 | /* The linker's interface for issuing a warning or error message. */ |
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257 | |||
258 | typedef |
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259 | enum ld_plugin_status |
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260 | (*ld_plugin_message) (int level, const char *format, ...); |
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261 | |||
262 | /* The linker's interface for retrieving the number of sections in an object. |
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263 | The handle is obtained in the claim_file handler. This interface should |
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264 | only be invoked in the claim_file handler. This function sets *COUNT to |
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265 | the number of sections in the object. */ |
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266 | |||
267 | typedef |
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268 | enum ld_plugin_status |
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269 | (*ld_plugin_get_input_section_count) (const void* handle, unsigned int *count); |
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270 | |||
271 | /* The linker's interface for retrieving the section type of a specific |
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272 | section in an object. This interface should only be invoked in the |
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273 | claim_file handler. This function sets *TYPE to an ELF SHT_xxx value. */ |
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274 | |||
275 | typedef |
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276 | enum ld_plugin_status |
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277 | (*ld_plugin_get_input_section_type) (const struct ld_plugin_section section, |
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278 | unsigned int *type); |
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279 | |||
280 | /* The linker's interface for retrieving the name of a specific section in |
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281 | an object. This interface should only be invoked in the claim_file handler. |
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282 | This function sets *SECTION_NAME_PTR to a null-terminated buffer allocated |
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283 | by malloc. The plugin must free *SECTION_NAME_PTR. */ |
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284 | |||
285 | typedef |
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286 | enum ld_plugin_status |
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287 | (*ld_plugin_get_input_section_name) (const struct ld_plugin_section section, |
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288 | char **section_name_ptr); |
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289 | |||
290 | /* The linker's interface for retrieving the contents of a specific section |
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291 | in an object. This interface should only be invoked in the claim_file |
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292 | handler. This function sets *SECTION_CONTENTS to point to a buffer that is |
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293 | valid until clam_file handler returns. It sets *LEN to the size of the |
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294 | buffer. */ |
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295 | |||
296 | typedef |
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297 | enum ld_plugin_status |
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298 | (*ld_plugin_get_input_section_contents) (const struct ld_plugin_section section, |
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299 | const unsigned char **section_contents, |
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300 | size_t* len); |
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301 | |||
302 | /* The linker's interface for specifying the desired order of sections. |
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303 | The sections should be specifed using the array SECTION_LIST in the |
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304 | order in which they should appear in the final layout. NUM_SECTIONS |
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305 | specifies the number of entries in each array. This should be invoked |
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306 | in the all_symbols_read handler. */ |
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307 | |||
308 | typedef |
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309 | enum ld_plugin_status |
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310 | (*ld_plugin_update_section_order) (const struct ld_plugin_section *section_list, |
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311 | unsigned int num_sections); |
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312 | |||
313 | /* The linker's interface for specifying that reordering of sections is |
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314 | desired so that the linker can prepare for it. This should be invoked |
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315 | before update_section_order, preferably in the claim_file handler. */ |
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316 | |||
317 | typedef |
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318 | enum ld_plugin_status |
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319 | (*ld_plugin_allow_section_ordering) (void); |
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320 | |||
321 | /* The linker's interface for specifying that a subset of sections is |
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322 | to be mapped to a unique segment. If the plugin wants to call |
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323 | unique_segment_for_sections, it must call this function from a |
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324 | claim_file_handler or when it is first loaded. */ |
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325 | |||
326 | typedef |
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327 | enum ld_plugin_status |
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328 | (*ld_plugin_allow_unique_segment_for_sections) (void); |
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329 | |||
330 | /* The linker's interface for specifying that a specific set of sections |
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331 | must be mapped to a unique segment. ELF segments do not have names |
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332 | and the NAME is used as the name of the newly created output section |
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333 | that is then placed in the unique PT_LOAD segment. FLAGS is used to |
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334 | specify if any additional segment flags need to be set. For instance, |
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335 | a specific segment flag can be set to identify this segment. Unsetting |
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336 | segment flags that would be set by default is not possible. The |
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337 | parameter SEGMENT_ALIGNMENT when non-zero will override the default. */ |
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338 | |||
339 | typedef |
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340 | enum ld_plugin_status |
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341 | (*ld_plugin_unique_segment_for_sections) ( |
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342 | const char* segment_name, |
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343 | uint64_t segment_flags, |
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344 | uint64_t segment_alignment, |
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345 | const struct ld_plugin_section * section_list, |
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346 | unsigned int num_sections); |
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347 | |||
348 | enum ld_plugin_level |
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349 | { |
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350 | LDPL_INFO, |
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351 | LDPL_WARNING, |
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352 | LDPL_ERROR, |
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353 | LDPL_FATAL |
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354 | }; |
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355 | |||
356 | /* Values for the tv_tag field of the transfer vector. */ |
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357 | |||
358 | enum ld_plugin_tag |
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359 | { |
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360 | LDPT_NULL = 0, |
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361 | LDPT_API_VERSION = 1, |
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362 | LDPT_GOLD_VERSION = 2, |
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363 | LDPT_LINKER_OUTPUT = 3, |
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364 | LDPT_OPTION = 4, |
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365 | LDPT_REGISTER_CLAIM_FILE_HOOK = 5, |
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366 | LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK = 6, |
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367 | LDPT_REGISTER_CLEANUP_HOOK = 7, |
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368 | LDPT_ADD_SYMBOLS = 8, |
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369 | LDPT_GET_SYMBOLS = 9, |
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370 | LDPT_ADD_INPUT_FILE = 10, |
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371 | LDPT_MESSAGE = 11, |
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372 | LDPT_GET_INPUT_FILE = 12, |
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373 | LDPT_RELEASE_INPUT_FILE = 13, |
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374 | LDPT_ADD_INPUT_LIBRARY = 14, |
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375 | LDPT_OUTPUT_NAME = 15, |
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376 | LDPT_SET_EXTRA_LIBRARY_PATH = 16, |
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377 | LDPT_GNU_LD_VERSION = 17, |
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378 | LDPT_GET_VIEW = 18, |
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379 | LDPT_GET_INPUT_SECTION_COUNT = 19, |
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380 | LDPT_GET_INPUT_SECTION_TYPE = 20, |
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381 | LDPT_GET_INPUT_SECTION_NAME = 21, |
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382 | LDPT_GET_INPUT_SECTION_CONTENTS = 22, |
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383 | LDPT_UPDATE_SECTION_ORDER = 23, |
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384 | LDPT_ALLOW_SECTION_ORDERING = 24, |
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385 | LDPT_GET_SYMBOLS_V2 = 25, |
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386 | LDPT_ALLOW_UNIQUE_SEGMENT_FOR_SECTIONS = 26, |
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387 | LDPT_UNIQUE_SEGMENT_FOR_SECTIONS = 27 |
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388 | }; |
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389 | |||
390 | /* The plugin transfer vector. */ |
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391 | |||
392 | struct ld_plugin_tv |
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393 | { |
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394 | enum ld_plugin_tag tv_tag; |
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395 | union |
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396 | { |
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397 | int tv_val; |
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398 | const char *tv_string; |
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399 | ld_plugin_register_claim_file tv_register_claim_file; |
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400 | ld_plugin_register_all_symbols_read tv_register_all_symbols_read; |
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401 | ld_plugin_register_cleanup tv_register_cleanup; |
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402 | ld_plugin_add_symbols tv_add_symbols; |
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403 | ld_plugin_get_symbols tv_get_symbols; |
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404 | ld_plugin_add_input_file tv_add_input_file; |
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405 | ld_plugin_message tv_message; |
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406 | ld_plugin_get_input_file tv_get_input_file; |
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407 | ld_plugin_get_view tv_get_view; |
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408 | ld_plugin_release_input_file tv_release_input_file; |
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409 | ld_plugin_add_input_library tv_add_input_library; |
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410 | ld_plugin_set_extra_library_path tv_set_extra_library_path; |
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411 | ld_plugin_get_input_section_count tv_get_input_section_count; |
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412 | ld_plugin_get_input_section_type tv_get_input_section_type; |
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413 | ld_plugin_get_input_section_name tv_get_input_section_name; |
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414 | ld_plugin_get_input_section_contents tv_get_input_section_contents; |
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415 | ld_plugin_update_section_order tv_update_section_order; |
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416 | ld_plugin_allow_section_ordering tv_allow_section_ordering; |
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417 | ld_plugin_allow_unique_segment_for_sections tv_allow_unique_segment_for_sections; |
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418 | ld_plugin_unique_segment_for_sections tv_unique_segment_for_sections; |
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419 | } tv_u; |
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420 | }; |
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421 | |||
422 | /* The plugin library's "onload" entry point. */ |
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423 | |||
424 | typedef |
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425 | enum ld_plugin_status |
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426 | (*ld_plugin_onload) (struct ld_plugin_tv *tv); |
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427 | |||
428 | #ifdef __cplusplus |
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429 | } |
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430 | #endif |
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431 | |||
432 | #endif /* !defined(PLUGIN_API_H) */> |