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| 1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. |
| 4 |
| 5 #include "tools/gn/operators.h" |
| 6 |
| 7 #include "base/strings/string_number_conversions.h" |
| 8 #include "tools/gn/err.h" |
| 9 #include "tools/gn/parse_tree.h" |
| 10 #include "tools/gn/scope.h" |
| 11 #include "tools/gn/token.h" |
| 12 #include "tools/gn/value.h" |
| 13 |
| 14 namespace { |
| 15 |
| 16 const char kSourcesName[] = "sources"; |
| 17 |
| 18 // Applies the sources assignment filter from the given scope to each element |
| 19 // of source (can be a list or a string), appending it to dest if it doesn't |
| 20 // match. |
| 21 void AppendFilteredSourcesToValue(const Scope* scope, |
| 22 const Value& source, |
| 23 Value* dest) { |
| 24 const PatternList* filter = scope->GetSourcesAssignmentFilter(); |
| 25 |
| 26 const std::vector<Value>& source_list = source.list_value(); |
| 27 |
| 28 if (source.type() == Value::STRING) { |
| 29 if (!filter || filter->is_empty() || |
| 30 !filter->MatchesValue(source)) |
| 31 dest->list_value().push_back(source); |
| 32 return; |
| 33 } |
| 34 |
| 35 // Otherwise source is a list. |
| 36 DCHECK(source.type() == Value::LIST); |
| 37 if (!filter || filter->is_empty()) { |
| 38 // No filter, append everything. |
| 39 for (size_t i = 0; i < source_list.size(); i++) |
| 40 dest->list_value().push_back(source_list[i]); |
| 41 return; |
| 42 } |
| 43 |
| 44 // Note: don't reserve() the dest vector here since that actually hurts |
| 45 // the allocation pattern when the build script is doing multiple small |
| 46 // additions. |
| 47 for (size_t i = 0; i < source_list.size(); i++) { |
| 48 if (!filter->MatchesValue(source_list[i])) |
| 49 dest->list_value().push_back(source_list[i]); |
| 50 } |
| 51 } |
| 52 |
| 53 void RemoveMatchesFromList(const BinaryOpNode* op_node, |
| 54 Value* list, |
| 55 const Value& to_remove, |
| 56 Err* err) { |
| 57 std::vector<Value>& v = list->list_value(); |
| 58 switch (to_remove.type()) { |
| 59 case Value::INTEGER: // Filter out the individual int/string. |
| 60 case Value::STRING: { |
| 61 bool found_match = false; |
| 62 for (size_t i = 0; i < v.size(); /* nothing */) { |
| 63 if (v[i] == to_remove) { |
| 64 found_match = true; |
| 65 v.erase(v.begin() + i); |
| 66 } else { |
| 67 i++; |
| 68 } |
| 69 } |
| 70 if (!found_match) { |
| 71 *err = Err(to_remove.origin()->GetRange(), "Item not found", |
| 72 "You were trying to remove \"" + to_remove.ToString() + |
| 73 "\"\nfrom the list but it wasn't there."); |
| 74 } |
| 75 break; |
| 76 } |
| 77 |
| 78 case Value::LIST: // Filter out each individual thing. |
| 79 for (size_t i = 0; i < to_remove.list_value().size(); i++) { |
| 80 // TODO(brettw) if the nested item is a list, we may want to search |
| 81 // for the literal list rather than remote the items in it. |
| 82 RemoveMatchesFromList(op_node, list, to_remove.list_value()[i], err); |
| 83 if (err->has_error()) |
| 84 return; |
| 85 } |
| 86 break; |
| 87 |
| 88 default: |
| 89 break; |
| 90 } |
| 91 } |
| 92 |
| 93 // Assignment ----------------------------------------------------------------- |
| 94 |
| 95 Value ExecuteEquals(Scope* scope, |
| 96 const BinaryOpNode* op_node, |
| 97 const Token& left, |
| 98 const Value& right, |
| 99 Err* err) { |
| 100 const Value* old_value = scope->GetValue(left.value(), false); |
| 101 if (old_value) { |
| 102 if (scope->IsSetButUnused(left.value())) { |
| 103 // Throw an error for re-assigning without using the value first. The |
| 104 // exception is that you can overwrite an empty list with another list |
| 105 // since this is the way to get around the "can't overwrite a nonempty |
| 106 // list with another nonempty list" restriction. |
| 107 if (old_value->type() != Value::LIST || |
| 108 !old_value->list_value().empty()) { |
| 109 *err = Err(op_node->left()->GetRange(), "Overwriting unused variable.", |
| 110 "This overwrites a previous assignment to \"" + |
| 111 left.value().as_string() + "\" that had no effect."); |
| 112 err->AppendSubErr(Err(*scope->GetValue(left.value()), |
| 113 "Previously set here.", |
| 114 "Maybe you wanted \"+=\" to append instead?")); |
| 115 return Value(); |
| 116 } |
| 117 } else { |
| 118 // Throw an error when overwriting a nonempty list with another nonempty |
| 119 // list item. This is to detect the case where you write |
| 120 // defines = ["FOO"] |
| 121 // and you overwrote inherited ones, when instead you mean to append: |
| 122 // defines += ["FOO"] |
| 123 if (old_value->type() == Value::LIST && |
| 124 !old_value->list_value().empty() && |
| 125 right.type() == Value::LIST && |
| 126 !right.list_value().empty()) { |
| 127 *err = Err(op_node->left()->GetRange(), "Replacing nonempty list.", |
| 128 std::string("This overwrites a previously-defined nonempty list ") + |
| 129 "(length " + base::IntToString(old_value->list_value().size()) + |
| 130 ")."); |
| 131 err->AppendSubErr(Err(*old_value, "for previous definition", |
| 132 "with another one (length " + |
| 133 base::IntToString(right.list_value().size()) + "). Did you mean " + |
| 134 "\"+=\" to append instead? If you\nreally want to do this, do\n " + |
| 135 left.value().as_string() + " = []\nbefore reassigning.")); |
| 136 return Value(); |
| 137 } |
| 138 } |
| 139 } |
| 140 if (err->has_error()) |
| 141 return Value(); |
| 142 |
| 143 if (right.type() == Value::LIST && left.value() == kSourcesName) { |
| 144 // Assigning to sources, filter the list. Here we do the filtering and |
| 145 // copying in one step to save an extra list copy (the lists may be |
| 146 // long). |
| 147 Value* set_value = scope->SetValue(left.value(), |
| 148 Value(op_node, Value::LIST), op_node); |
| 149 set_value->list_value().reserve(right.list_value().size()); |
| 150 AppendFilteredSourcesToValue(scope, right, set_value); |
| 151 } else { |
| 152 // Normal value set, just copy it. |
| 153 scope->SetValue(left.value(), right, op_node->right()); |
| 154 } |
| 155 return Value(); |
| 156 } |
| 157 |
| 158 // allow_type_conversion indicates if we're allowed to change the type of the |
| 159 // left value. This is set to true when doing +, and false when doing +=. |
| 160 void ValuePlusEquals(const Scope* scope, |
| 161 const BinaryOpNode* op_node, |
| 162 const Token& left_token, |
| 163 Value* left, |
| 164 const Value& right, |
| 165 bool allow_type_conversion, |
| 166 Err* err) { |
| 167 switch (left->type()) { |
| 168 // Left-hand-side int. |
| 169 case Value::INTEGER: |
| 170 switch (right.type()) { |
| 171 case Value::INTEGER: // int + int -> addition. |
| 172 left->int_value() += right.int_value(); |
| 173 return; |
| 174 |
| 175 case Value::STRING: // int + string -> string concat. |
| 176 if (allow_type_conversion) { |
| 177 *left = Value(op_node, |
| 178 base::Int64ToString(left->int_value()) + right.string_value()); |
| 179 return; |
| 180 } |
| 181 break; |
| 182 |
| 183 default: |
| 184 break; |
| 185 } |
| 186 break; |
| 187 |
| 188 // Left-hand-side string. |
| 189 case Value::STRING: |
| 190 switch (right.type()) { |
| 191 case Value::INTEGER: // string + int -> string concat. |
| 192 left->string_value().append(base::Int64ToString(right.int_value())); |
| 193 return; |
| 194 |
| 195 case Value::STRING: // string + string -> string contat. |
| 196 left->string_value().append(right.string_value()); |
| 197 return; |
| 198 |
| 199 default: |
| 200 break; |
| 201 } |
| 202 break; |
| 203 |
| 204 // Left-hand-side list. |
| 205 case Value::LIST: |
| 206 switch (right.type()) { |
| 207 case Value::INTEGER: // list + integer -> list append. |
| 208 case Value::STRING: // list + string -> list append. |
| 209 if (left_token.value() == kSourcesName) |
| 210 AppendFilteredSourcesToValue(scope, right, left); |
| 211 else |
| 212 left->list_value().push_back(right); |
| 213 return; |
| 214 |
| 215 case Value::LIST: // list + list -> list concat. |
| 216 if (left_token.value() == kSourcesName) { |
| 217 // Filter additions through the assignment filter. |
| 218 AppendFilteredSourcesToValue(scope, right, left); |
| 219 } else { |
| 220 // Normal list concat. |
| 221 for (size_t i = 0; i < right.list_value().size(); i++) |
| 222 left->list_value().push_back(right.list_value()[i]); |
| 223 } |
| 224 return; |
| 225 |
| 226 default: |
| 227 break; |
| 228 } |
| 229 |
| 230 default: |
| 231 break; |
| 232 } |
| 233 |
| 234 *err = Err(op_node->op(), "Incompatible types to add.", |
| 235 std::string("I see a ") + Value::DescribeType(left->type()) + " and a " + |
| 236 Value::DescribeType(right.type()) + "."); |
| 237 } |
| 238 |
| 239 Value ExecutePlusEquals(Scope* scope, |
| 240 const BinaryOpNode* op_node, |
| 241 const Token& left, |
| 242 const Value& right, |
| 243 Err* err) { |
| 244 // We modify in-place rather than doing read-modify-write to avoid |
| 245 // copying large lists. |
| 246 Value* left_value = |
| 247 scope->GetValueForcedToCurrentScope(left.value(), op_node); |
| 248 if (!left_value) { |
| 249 *err = Err(left, "Undefined variable for +=.", |
| 250 "I don't have something with this name in scope now."); |
| 251 return Value(); |
| 252 } |
| 253 ValuePlusEquals(scope, op_node, left, left_value, right, false, err); |
| 254 left_value->set_origin(op_node); |
| 255 scope->MarkUnused(left.value()); |
| 256 return Value(); |
| 257 } |
| 258 |
| 259 void ValueMinusEquals(const BinaryOpNode* op_node, |
| 260 Value* left, |
| 261 const Value& right, |
| 262 bool allow_type_conversion, |
| 263 Err* err) { |
| 264 switch (left->type()) { |
| 265 // Left-hand-side int. |
| 266 case Value::INTEGER: |
| 267 switch (right.type()) { |
| 268 case Value::INTEGER: // int - int -> subtraction. |
| 269 left->int_value() -= right.int_value(); |
| 270 return; |
| 271 |
| 272 default: |
| 273 break; |
| 274 } |
| 275 break; |
| 276 |
| 277 // Left-hand-side string. |
| 278 case Value::STRING: |
| 279 break; // All are errors. |
| 280 |
| 281 // Left-hand-side list. |
| 282 case Value::LIST: |
| 283 RemoveMatchesFromList(op_node, left, right, err); |
| 284 return; |
| 285 |
| 286 default: |
| 287 break; |
| 288 } |
| 289 |
| 290 *err = Err(op_node->op(), "Incompatible types to add.", |
| 291 std::string("I see a ") + Value::DescribeType(left->type()) + " and a " + |
| 292 Value::DescribeType(right.type()) + "."); |
| 293 } |
| 294 |
| 295 Value ExecuteMinusEquals(Scope* scope, |
| 296 const BinaryOpNode* op_node, |
| 297 const Token& left, |
| 298 const Value& right, |
| 299 Err* err) { |
| 300 Value* left_value = |
| 301 scope->GetValueForcedToCurrentScope(left.value(), op_node); |
| 302 if (!left_value) { |
| 303 *err = Err(left, "Undefined variable for -=.", |
| 304 "I don't have something with this name in scope now."); |
| 305 return Value(); |
| 306 } |
| 307 ValueMinusEquals(op_node, left_value, right, false, err); |
| 308 left_value->set_origin(op_node); |
| 309 scope->MarkUnused(left.value()); |
| 310 return Value(); |
| 311 } |
| 312 |
| 313 // Plus/Minus ----------------------------------------------------------------- |
| 314 |
| 315 Value ExecutePlus(Scope* scope, |
| 316 const BinaryOpNode* op_node, |
| 317 const Value& left, |
| 318 const Value& right, |
| 319 Err* err) { |
| 320 Value ret = left; |
| 321 ValuePlusEquals(scope, op_node, Token(), &ret, right, true, err); |
| 322 ret.set_origin(op_node); |
| 323 return ret; |
| 324 } |
| 325 |
| 326 Value ExecuteMinus(Scope* scope, |
| 327 const BinaryOpNode* op_node, |
| 328 const Value& left, |
| 329 const Value& right, |
| 330 Err* err) { |
| 331 Value ret = left; |
| 332 ValueMinusEquals(op_node, &ret, right, true, err); |
| 333 ret.set_origin(op_node); |
| 334 return ret; |
| 335 } |
| 336 |
| 337 // Comparison ----------------------------------------------------------------- |
| 338 |
| 339 Value ExecuteEqualsEquals(Scope* scope, |
| 340 const BinaryOpNode* op_node, |
| 341 const Value& left, |
| 342 const Value& right, |
| 343 Err* err) { |
| 344 if (left == right) |
| 345 return Value(op_node, 1); |
| 346 return Value(op_node, 0); |
| 347 } |
| 348 |
| 349 Value ExecuteNotEquals(Scope* scope, |
| 350 const BinaryOpNode* op_node, |
| 351 const Value& left, |
| 352 const Value& right, |
| 353 Err* err) { |
| 354 // Evaluate in terms of ==. |
| 355 Value result = ExecuteEqualsEquals(scope, op_node, left, right, err); |
| 356 result.int_value() = static_cast<int64>(!result.int_value()); |
| 357 return result; |
| 358 } |
| 359 |
| 360 Value FillNeedsToIntegersError(const BinaryOpNode* op_node, |
| 361 const Value& left, |
| 362 const Value& right, |
| 363 Err* err) { |
| 364 *err = Err(op_node, "Comparison requires two integers.", |
| 365 "This operator can only compare two integers."); |
| 366 err->AppendRange(left.origin()->GetRange()); |
| 367 err->AppendRange(right.origin()->GetRange()); |
| 368 return Value(); |
| 369 } |
| 370 |
| 371 Value ExecuteLessEquals(Scope* scope, |
| 372 const BinaryOpNode* op_node, |
| 373 const Value& left, |
| 374 const Value& right, |
| 375 Err* err) { |
| 376 if (left.type() != Value::INTEGER || right.type() != Value::INTEGER) |
| 377 return FillNeedsToIntegersError(op_node, left, right, err); |
| 378 return Value(op_node, left.int_value() <= right.int_value()); |
| 379 } |
| 380 |
| 381 Value ExecuteGreaterEquals(Scope* scope, |
| 382 const BinaryOpNode* op_node, |
| 383 const Value& left, |
| 384 const Value& right, |
| 385 Err* err) { |
| 386 if (left.type() != Value::INTEGER || right.type() != Value::INTEGER) |
| 387 return FillNeedsToIntegersError(op_node, left, right, err); |
| 388 return Value(op_node, left.int_value() >= right.int_value()); |
| 389 } |
| 390 |
| 391 Value ExecuteGreater(Scope* scope, |
| 392 const BinaryOpNode* op_node, |
| 393 const Value& left, |
| 394 const Value& right, |
| 395 Err* err) { |
| 396 if (left.type() != Value::INTEGER || right.type() != Value::INTEGER) |
| 397 return FillNeedsToIntegersError(op_node, left, right, err); |
| 398 return Value(op_node, left.int_value() > right.int_value()); |
| 399 } |
| 400 |
| 401 Value ExecuteLess(Scope* scope, |
| 402 const BinaryOpNode* op_node, |
| 403 const Value& left, |
| 404 const Value& right, |
| 405 Err* err) { |
| 406 if (left.type() != Value::INTEGER || right.type() != Value::INTEGER) |
| 407 return FillNeedsToIntegersError(op_node, left, right, err); |
| 408 return Value(op_node, left.int_value() < right.int_value()); |
| 409 } |
| 410 |
| 411 // Binary ---------------------------------------------------------------------- |
| 412 |
| 413 Value ExecuteOr(Scope* scope, |
| 414 const BinaryOpNode* op_node, |
| 415 const Value& left, |
| 416 const Value& right, |
| 417 Err* err) { |
| 418 return Value(op_node, |
| 419 static_cast<int64>(left.InterpretAsInt() || right.InterpretAsInt())); |
| 420 } |
| 421 |
| 422 Value ExecuteAnd(Scope* scope, |
| 423 const BinaryOpNode* op_node, |
| 424 const Value& left, |
| 425 const Value& right, |
| 426 Err* err) { |
| 427 return Value(op_node, |
| 428 static_cast<int64>(left.InterpretAsInt() && right.InterpretAsInt())); |
| 429 } |
| 430 |
| 431 } // namespace |
| 432 |
| 433 // ---------------------------------------------------------------------------- |
| 434 |
| 435 bool IsUnaryOperator(const Token& token) { |
| 436 if (token.type() != Token::OPERATOR) |
| 437 return false; |
| 438 return token.value() == "!"; |
| 439 } |
| 440 |
| 441 bool IsBinaryOperator(const Token& token) { |
| 442 if (token.type() != Token::OPERATOR) |
| 443 return false; |
| 444 return token.value() == "=" || |
| 445 token.value() == "+=" || |
| 446 token.value() == "-=" || |
| 447 token.value() == "+" || |
| 448 token.value() == "-" || |
| 449 token.value() == "==" || |
| 450 token.value() == "!=" || |
| 451 token.value() == "<=" || |
| 452 token.value() == ">=" || |
| 453 token.value() == "<" || |
| 454 token.value() == ">" || |
| 455 token.value() == "&&" || |
| 456 token.value() == "||"; |
| 457 } |
| 458 |
| 459 bool IsFunctionCallArgBeginScoper(const Token& token) { |
| 460 return token.IsScoperEqualTo("("); |
| 461 } |
| 462 |
| 463 bool IsFunctionCallArgEndScoper(const Token& token) { |
| 464 return token.IsScoperEqualTo(")"); |
| 465 } |
| 466 |
| 467 bool IsScopeBeginScoper(const Token& token) { |
| 468 return token.IsScoperEqualTo("{"); |
| 469 } |
| 470 |
| 471 bool IsScopeEndScoper(const Token& token) { |
| 472 return token.IsScoperEqualTo("}"); |
| 473 } |
| 474 |
| 475 Value ExecuteUnaryOperator(Scope* scope, |
| 476 const UnaryOpNode* op_node, |
| 477 const Value& expr, |
| 478 Err* err) { |
| 479 DCHECK(op_node->op().IsOperatorEqualTo("!")); |
| 480 return Value(op_node, !expr.InterpretAsInt()); |
| 481 } |
| 482 |
| 483 Value ExecuteBinaryOperator(Scope* scope, |
| 484 const BinaryOpNode* op_node, |
| 485 const ParseNode* left, |
| 486 const ParseNode* right, |
| 487 Err* err) { |
| 488 const Token& op = op_node->op(); |
| 489 |
| 490 // First handle the ones that take an lvalue. |
| 491 if (op.IsOperatorEqualTo("=") || |
| 492 op.IsOperatorEqualTo("+=") || |
| 493 op.IsOperatorEqualTo("-=")) { |
| 494 const IdentifierNode* left_id = left->AsIdentifier(); |
| 495 if (!left_id) { |
| 496 *err = Err(op, "Operator requires an lvalue.", |
| 497 "This thing on the left is not an idenfitier."); |
| 498 err->AppendRange(left->GetRange()); |
| 499 return Value(); |
| 500 } |
| 501 const Token& dest = left_id->value(); |
| 502 |
| 503 Value right_value = right->Execute(scope, err); |
| 504 if (err->has_error()) |
| 505 return Value(); |
| 506 if (right_value.type() == Value::NONE) { |
| 507 *err = Err(op, "Operator requires an rvalue.", |
| 508 "This thing on the right does not evaluate to a value."); |
| 509 err->AppendRange(right->GetRange()); |
| 510 return Value(); |
| 511 } |
| 512 |
| 513 if (op.IsOperatorEqualTo("=")) |
| 514 return ExecuteEquals(scope, op_node, dest, right_value, err); |
| 515 if (op.IsOperatorEqualTo("+=")) |
| 516 return ExecutePlusEquals(scope, op_node, dest, right_value, err); |
| 517 if (op.IsOperatorEqualTo("-=")) |
| 518 return ExecuteMinusEquals(scope, op_node, dest, right_value, err); |
| 519 NOTREACHED(); |
| 520 return Value(); |
| 521 } |
| 522 |
| 523 // Left value. |
| 524 Value left_value = left->Execute(scope, err); |
| 525 if (err->has_error()) |
| 526 return Value(); |
| 527 if (left_value.type() == Value::NONE) { |
| 528 *err = Err(op, "Operator requires an value.", |
| 529 "This thing on the left does not evaluate to a value."); |
| 530 err->AppendRange(left->GetRange()); |
| 531 return Value(); |
| 532 } |
| 533 |
| 534 // Right value. Note: don't move this above to share code with the lvalue |
| 535 // version since in this case we want to execute the left side first. |
| 536 Value right_value = right->Execute(scope, err); |
| 537 if (err->has_error()) |
| 538 return Value(); |
| 539 if (right_value.type() == Value::NONE) { |
| 540 *err = Err(op, "Operator requires an value.", |
| 541 "This thing on the right does not evaluate to a value."); |
| 542 err->AppendRange(right->GetRange()); |
| 543 return Value(); |
| 544 } |
| 545 |
| 546 // +, -. |
| 547 if (op.IsOperatorEqualTo("-")) |
| 548 return ExecuteMinus(scope, op_node, left_value, right_value, err); |
| 549 if (op.IsOperatorEqualTo("+")) |
| 550 return ExecutePlus(scope, op_node, left_value, right_value, err); |
| 551 |
| 552 // Comparisons. |
| 553 if (op.IsOperatorEqualTo("==")) |
| 554 return ExecuteEqualsEquals(scope, op_node, left_value, right_value, err); |
| 555 if (op.IsOperatorEqualTo("!=")) |
| 556 return ExecuteNotEquals(scope, op_node, left_value, right_value, err); |
| 557 if (op.IsOperatorEqualTo(">=")) |
| 558 return ExecuteGreaterEquals(scope, op_node, left_value, right_value, err); |
| 559 if (op.IsOperatorEqualTo("<=")) |
| 560 return ExecuteLessEquals(scope, op_node, left_value, right_value, err); |
| 561 if (op.IsOperatorEqualTo(">")) |
| 562 return ExecuteGreater(scope, op_node, left_value, right_value, err); |
| 563 if (op.IsOperatorEqualTo("<")) |
| 564 return ExecuteLess(scope, op_node, left_value, right_value, err); |
| 565 |
| 566 // ||, &&. |
| 567 if (op.IsOperatorEqualTo("||")) |
| 568 return ExecuteOr(scope, op_node, left_value, right_value, err); |
| 569 if (op.IsOperatorEqualTo("&&")) |
| 570 return ExecuteAnd(scope, op_node, left_value, right_value, err); |
| 571 |
| 572 return Value(); |
| 573 } |
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