| 1 | // arm-reloc-property.cc -- ARM relocation property. |
| 2 | |
| 3 | // Copyright (C) 2010-2019 Free Software Foundation, Inc. |
| 4 | // Written by Doug Kwan <dougkwan@google.com>. |
| 5 | |
| 6 | // This file is part of gold. |
| 7 | |
| 8 | // This program is free software; you can redistribute it and/or modify |
| 9 | // it under the terms of the GNU General Public License as published by |
| 10 | // the Free Software Foundation; either version 3 of the License, or |
| 11 | // (at your option) any later version. |
| 12 | |
| 13 | // This program is distributed in the hope that it will be useful, |
| 14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | // GNU General Public License for more details. |
| 17 | |
| 18 | // You should have received a copy of the GNU General Public License |
| 19 | // along with this program; if not, write to the Free Software |
| 20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 21 | // MA 02110-1301, USA. |
| 22 | |
| 23 | #include "gold.h" |
| 24 | |
| 25 | #include <cstdio> |
| 26 | #include <cstring> |
| 27 | #include <stack> |
| 28 | #include <string> |
| 29 | #include <vector> |
| 30 | |
| 31 | #include "elfcpp.h" |
| 32 | #include "arm.h" |
| 33 | #include "arm-reloc-property.h" |
| 34 | |
| 35 | namespace gold |
| 36 | { |
| 37 | |
| 38 | // Arm_reloc_property::Tree_node methods. |
| 39 | |
| 40 | // Parse an S-expression S and build a tree and return the root node. |
| 41 | // Caller is responsible for releasing tree after use. |
| 42 | |
| 43 | Arm_reloc_property::Tree_node* |
| 44 | Arm_reloc_property::Tree_node::make_tree(const std::string& s) |
| 45 | { |
| 46 | std::stack<size_t> size_stack; |
| 47 | Tree_node_vector node_stack; |
| 48 | |
| 49 | // strtok needs a non-const string pointer. |
| 50 | char* buffer = new char[s.size() + 1]; |
| 51 | memcpy(buffer, s.data(), s.size()); |
| 52 | buffer[s.size()] = '\0'; |
| 53 | char* token = strtok(buffer, " "); |
| 54 | |
| 55 | while (token != NULL) |
| 56 | { |
| 57 | if (strcmp(token, "(") == 0) |
| 58 | // Remember the node stack position for start of a new internal node. |
| 59 | size_stack.push(node_stack.size()); |
| 60 | else if (strcmp(token, ")") == 0) |
| 61 | { |
| 62 | // Pop all tree nodes after the previous '(' and use them as |
| 63 | // children to build a new internal node. Push internal node back. |
| 64 | size_t current_size = node_stack.size(); |
| 65 | size_t prev_size = size_stack.top(); |
| 66 | size_stack.pop(); |
| 67 | Tree_node* node = |
| 68 | new Tree_node(node_stack.begin() + prev_size, |
| 69 | node_stack.begin() + current_size); |
| 70 | node_stack.resize(prev_size); |
| 71 | node_stack.push_back(node); |
| 72 | } |
| 73 | else |
| 74 | // Just push a leaf node to node_stack. |
| 75 | node_stack.push_back(new Tree_node(token)); |
| 76 | |
| 77 | token = strtok(NULL, " "); |
| 78 | } |
| 79 | |
| 80 | delete[] buffer; |
| 81 | |
| 82 | // At this point, size_stack should be empty and node_stack should only |
| 83 | // contain the root node. |
| 84 | gold_assert(size_stack.empty() && node_stack.size() == 1); |
| 85 | return node_stack[0]; |
| 86 | } |
| 87 | |
| 88 | // Arm_reloc_property methods. |
| 89 | |
| 90 | // Constructor. |
| 91 | |
| 92 | Arm_reloc_property::Arm_reloc_property( |
| 93 | unsigned int code, |
| 94 | const char* name, |
| 95 | Reloc_type rtype, |
| 96 | bool is_deprecated, |
| 97 | Reloc_class rclass, |
| 98 | const std::string& operation, |
| 99 | bool is_implemented, |
| 100 | int group_index, |
| 101 | bool checks_overflow) |
| 102 | : code_(code), name_(name), reloc_type_(rtype), reloc_class_(rclass), |
| 103 | group_index_(group_index), size_(0), align_(1), |
| 104 | relative_address_base_(RAB_NONE), is_deprecated_(is_deprecated), |
| 105 | is_implemented_(is_implemented), checks_overflow_(checks_overflow), |
| 106 | uses_got_entry_(false), uses_got_origin_(false), uses_plt_entry_(false), |
| 107 | uses_thumb_bit_(false), uses_symbol_base_(false), uses_addend_(false), |
| 108 | uses_symbol_(false) |
| 109 | { |
| 110 | // Set size and alignment of static and dynamic relocations. |
| 111 | if (rtype == RT_STATIC) |
| 112 | { |
| 113 | switch (rclass) |
| 114 | { |
| 115 | case RC_DATA: |
| 116 | // Except for R_ARM_ABS16 and R_ARM_ABS8, all static data relocations |
| 117 | // have size 4. All static data relocations have alignment of 1. |
| 118 | if (code == elfcpp::R_ARM_ABS8) |
| 119 | this->size_ = 1; |
| 120 | else if (code == elfcpp::R_ARM_ABS16) |
| 121 | this->size_ = 2; |
| 122 | else |
| 123 | this->size_ = 4; |
| 124 | this->align_ = 1; |
| 125 | break; |
| 126 | case RC_MISC: |
| 127 | // R_ARM_V4BX should be treated as an ARM relocation. For all |
| 128 | // others, just use defaults. |
| 129 | if (code != elfcpp::R_ARM_V4BX) |
| 130 | break; |
| 131 | // Fall through. |
| 132 | case RC_ARM: |
| 133 | this->size_ = 4; |
| 134 | this->align_ = 4; |
| 135 | break; |
| 136 | case RC_THM16: |
| 137 | this->size_ = 2; |
| 138 | this->align_ = 2; |
| 139 | break; |
| 140 | case RC_THM32: |
| 141 | this->size_ = 4; |
| 142 | this->align_ = 2; |
| 143 | break; |
| 144 | default: |
| 145 | gold_unreachable(); |
| 146 | } |
| 147 | } |
| 148 | else if (rtype == RT_DYNAMIC) |
| 149 | { |
| 150 | // With the exception of R_ARM_COPY, all dynamic relocations requires |
| 151 | // that the place being relocated is a word-aligned 32-bit object. |
| 152 | if (code != elfcpp::R_ARM_COPY) |
| 153 | { |
| 154 | this->size_ = 4; |
| 155 | this->align_ = 4; |
| 156 | } |
| 157 | } |
| 158 | |
| 159 | // If no relocation operation is specified, we are done. |
| 160 | if (operation == "NONE") |
| 161 | return; |
| 162 | |
| 163 | // Extract information from relocation operation. |
| 164 | Tree_node* root_node = Tree_node::make_tree(operation); |
| 165 | Tree_node* node = root_node; |
| 166 | |
| 167 | // Check for an expression of the form XXX - YYY. |
| 168 | if (!node->is_leaf() |
| 169 | && node->child(0)->is_leaf() |
| 170 | && node->child(0)->name() == "-") |
| 171 | { |
| 172 | struct RAB_table_entry |
| 173 | { |
| 174 | Relative_address_base rab; |
| 175 | const char* name; |
| 176 | }; |
| 177 | |
| 178 | static const RAB_table_entry rab_table[] = |
| 179 | { |
| 180 | { RAB_B_S, "( B S )" }, |
| 181 | { RAB_DELTA_B_S, "( DELTA_B ( S ) )" }, |
| 182 | { RAB_GOT_ORG, "GOT_ORG" }, |
| 183 | { RAB_P, "P" }, |
| 184 | { RAB_Pa, "Pa" }, |
| 185 | { RAB_TLS, "TLS" }, |
| 186 | { RAB_tp, "tp" } |
| 187 | }; |
| 188 | |
| 189 | static size_t rab_table_size = sizeof(rab_table) / sizeof(rab_table[0]); |
| 190 | const std::string rhs(node->child(2)->s_expression()); |
| 191 | for (size_t i = 0; i < rab_table_size; ++i) |
| 192 | if (rhs == rab_table[i].name) |
| 193 | { |
| 194 | this->relative_address_base_ = rab_table[i].rab; |
| 195 | break; |
| 196 | } |
| 197 | |
| 198 | gold_assert(this->relative_address_base_ != RAB_NONE); |
| 199 | if (this->relative_address_base_ == RAB_B_S) |
| 200 | this->uses_symbol_base_ = true; |
| 201 | node = node->child(1); |
| 202 | } |
| 203 | |
| 204 | // Check for an expression of the form XXX | T. |
| 205 | if (!node->is_leaf() |
| 206 | && node->child(0)->is_leaf() |
| 207 | && node->child(0)->name() == "|") |
| 208 | { |
| 209 | gold_assert(node->number_of_children() == 3 |
| 210 | && node->child(2)->is_leaf() |
| 211 | && node->child(2)->name() == "T"); |
| 212 | this->uses_thumb_bit_ = true; |
| 213 | node = node->child(1); |
| 214 | } |
| 215 | |
| 216 | // Check for an expression of the form XXX + A. |
| 217 | if (!node->is_leaf() |
| 218 | && node->child(0)->is_leaf() |
| 219 | && node->child(0)->name() == "+") |
| 220 | { |
| 221 | gold_assert(node->number_of_children() == 3 |
| 222 | && node->child(2)->is_leaf() |
| 223 | && node->child(2)->name() == "A"); |
| 224 | this->uses_addend_ = true; |
| 225 | node = node->child(1); |
| 226 | } |
| 227 | |
| 228 | // Check for an expression of the form XXX(S). |
| 229 | if (!node->is_leaf() && node->child(0)->is_leaf()) |
| 230 | { |
| 231 | gold_assert(node->number_of_children() == 2 |
| 232 | && node->child(1)->is_leaf() |
| 233 | && node->child(1)->name() == "S"); |
| 234 | const std::string func(node->child(0)->name()); |
| 235 | if (func == "B") |
| 236 | this->uses_symbol_base_ = true; |
| 237 | else if (func == "GOT") |
| 238 | this->uses_got_entry_ = true; |
| 239 | else if (func == "PLT") |
| 240 | this->uses_plt_entry_ = true; |
| 241 | else if (func == "Module" || func == "DELTA_B") |
| 242 | // These are used in dynamic relocations. |
| 243 | ; |
| 244 | else |
| 245 | gold_unreachable(); |
| 246 | node = node->child(1); |
| 247 | } |
| 248 | |
| 249 | gold_assert(node->is_leaf() && node->name() == "S"); |
| 250 | this->uses_symbol_ = true; |
| 251 | |
| 252 | delete root_node; |
| 253 | } |
| 254 | |
| 255 | // Arm_reloc_property_table methods. |
| 256 | |
| 257 | // Constructor. This processing informations in arm-reloc.def to |
| 258 | // initialize the table. |
| 259 | |
| 260 | Arm_reloc_property_table::Arm_reloc_property_table() |
| 261 | { |
| 262 | // These appear in arm-reloc.def. Do not rename them. |
| 263 | Parse_expression A("A"), GOT_ORG("GOT_ORG"), NONE("NONE"), P("P"), |
| 264 | Pa("Pa"), S("S"), T("T"), TLS("TLS"), tp("tp"); |
| 265 | const bool Y(true), N(false); |
| 266 | |
| 267 | for (unsigned int i = 0; i < Property_table_size; ++i) |
| 268 | this->table_[i] = NULL; |
| 269 | |
| 270 | #undef RD |
| 271 | #define RD(name, type, deprecated, class, operation, is_implemented, \ |
| 272 | group_index, checks_oveflow) \ |
| 273 | do \ |
| 274 | { \ |
| 275 | unsigned int code = elfcpp::R_ARM_##name; \ |
| 276 | gold_assert(code < Property_table_size); \ |
| 277 | this->table_[code] = \ |
| 278 | new Arm_reloc_property(elfcpp::R_ARM_##name, "R_ARM_" #name, \ |
| 279 | Arm_reloc_property::RT_##type, deprecated, \ |
| 280 | Arm_reloc_property::RC_##class, \ |
| 281 | (operation).s_expression(), is_implemented, \ |
| 282 | group_index, checks_oveflow); \ |
| 283 | } \ |
| 284 | while(0); |
| 285 | |
| 286 | #include "arm-reloc.def" |
| 287 | #undef RD |
| 288 | } |
| 289 | |
| 290 | // Return a string describing a relocation code that fails to get a |
| 291 | // relocation property in get_implemented_static_reloc_property(). |
| 292 | |
| 293 | std::string |
| 294 | Arm_reloc_property_table::reloc_name_in_error_message(unsigned int code) |
| 295 | { |
| 296 | gold_assert(code < Property_table_size); |
| 297 | |
| 298 | const Arm_reloc_property* arp = this->table_[code]; |
| 299 | |
| 300 | if (arp == NULL) |
| 301 | { |
| 302 | char buffer[100]; |
| 303 | sprintf(buffer, _("invalid reloc %u"), code); |
| 304 | return std::string(buffer); |
| 305 | } |
| 306 | |
| 307 | // gold only implements static relocation codes. |
| 308 | Arm_reloc_property::Reloc_type reloc_type = arp->reloc_type(); |
| 309 | gold_assert(reloc_type == Arm_reloc_property::RT_STATIC |
| 310 | || !arp->is_implemented()); |
| 311 | |
| 312 | const char* prefix = NULL; |
| 313 | switch (reloc_type) |
| 314 | { |
| 315 | case Arm_reloc_property::RT_STATIC: |
| 316 | prefix = arp->is_implemented() ? _("reloc ") : _("unimplemented reloc "); |
| 317 | break; |
| 318 | case Arm_reloc_property::RT_DYNAMIC: |
| 319 | prefix = _("dynamic reloc "); |
| 320 | break; |
| 321 | case Arm_reloc_property::RT_PRIVATE: |
| 322 | prefix = _("private reloc "); |
| 323 | break; |
| 324 | case Arm_reloc_property::RT_OBSOLETE: |
| 325 | prefix = _("obsolete reloc "); |
| 326 | break; |
| 327 | default: |
| 328 | gold_unreachable(); |
| 329 | } |
| 330 | return std::string(prefix) + arp->name(); |
| 331 | } |
| 332 | |
| 333 | } // End namespace gold. |