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.
5 #include "tools/gn/operators.h"
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"
16 const char kSourcesName[] = "sources";
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
21 void AppendFilteredSourcesToValue(const Scope* scope,
24 const PatternList* filter = scope->GetSourcesAssignmentFilter();
26 if (source.type() == Value::STRING) {
27 if (!filter || filter->is_empty() ||
28 !filter->MatchesValue(source))
29 dest->list_value().push_back(source);
32 if (source.type() != Value::LIST) {
33 // Any non-list and non-string being added to a list can just get appended,
34 // we're not going to filter it.
35 dest->list_value().push_back(source);
39 if (!filter || filter->is_empty()) {
40 // No filter, append everything.
41 for (const auto& source_entry : source.list_value())
42 dest->list_value().push_back(source_entry);
46 // Note: don't reserve() the dest vector here since that actually hurts
47 // the allocation pattern when the build script is doing multiple small
49 for (const auto& source_entry : source.list_value()) {
50 if (!filter->MatchesValue(source_entry))
51 dest->list_value().push_back(source_entry);
55 Value GetValueOrFillError(const BinaryOpNode* op_node,
56 const ParseNode* node,
60 Value value = node->Execute(scope, err);
63 if (value.type() == Value::NONE) {
64 *err = Err(op_node->op(),
65 "Operator requires a value.",
66 "This thing on the " + std::string(name) +
67 " does not evaluate to a value.");
68 err->AppendRange(node->GetRange());
74 void RemoveMatchesFromList(const BinaryOpNode* op_node,
76 const Value& to_remove,
78 std::vector<Value>& v = list->list_value();
79 switch (to_remove.type()) {
81 case Value::INTEGER: // Filter out the individual int/string.
83 bool found_match = false;
84 for (size_t i = 0; i < v.size(); /* nothing */) {
85 if (v[i] == to_remove) {
87 v.erase(v.begin() + i);
93 *err = Err(to_remove.origin()->GetRange(), "Item not found",
94 "You were trying to remove " + to_remove.ToString(true) +
95 "\nfrom the list but it wasn't there.");
100 case Value::LIST: // Filter out each individual thing.
101 for (size_t i = 0; i < to_remove.list_value().size(); i++) {
102 // TODO(brettw) if the nested item is a list, we may want to search
103 // for the literal list rather than remote the items in it.
104 RemoveMatchesFromList(op_node, list, to_remove.list_value()[i], err);
105 if (err->has_error())
115 // Assignment -----------------------------------------------------------------
117 // We return a null value from this rather than the result of doing the append.
118 // See ValuePlusEquals for rationale.
119 Value ExecuteEquals(Scope* scope,
120 const BinaryOpNode* op_node,
124 const Value* old_value = scope->GetValue(left.value(), false);
126 // Throw an error when overwriting a nonempty list with another nonempty
127 // list item. This is to detect the case where you write
129 // and you overwrote inherited ones, when instead you mean to append:
130 // defines += ["FOO"]
131 if (old_value->type() == Value::LIST &&
132 !old_value->list_value().empty() &&
133 right.type() == Value::LIST &&
134 !right.list_value().empty()) {
135 *err = Err(op_node->left()->GetRange(), "Replacing nonempty list.",
136 std::string("This overwrites a previously-defined nonempty list ") +
138 base::IntToString(static_cast<int>(old_value->list_value().size()))
140 err->AppendSubErr(Err(*old_value, "for previous definition",
141 "with another one (length " +
142 base::IntToString(static_cast<int>(right.list_value().size())) +
144 "\"+=\" to append instead? If you\nreally want to do this, do\n " +
145 left.value().as_string() + " = []\nbefore reassigning."));
149 if (err->has_error())
152 if (right.type() == Value::LIST && left.value() == kSourcesName) {
153 // Assigning to sources, filter the list. Here we do the filtering and
154 // copying in one step to save an extra list copy (the lists may be
156 Value* set_value = scope->SetValue(left.value(),
157 Value(op_node, Value::LIST), op_node);
158 set_value->list_value().reserve(right.list_value().size());
159 AppendFilteredSourcesToValue(scope, right, set_value);
161 // Normal value set, just copy it.
162 scope->SetValue(left.value(), right, op_node->right());
167 // allow_type_conversion indicates if we're allowed to change the type of the
168 // left value. This is set to true when doing +, and false when doing +=.
170 // Note that we return Value() from here, which is different than C++. This
171 // means you can't do clever things like foo = [ bar += baz ] to simultaneously
172 // append to and use a value. This is basically never needed in out build
173 // scripts and is just as likely an error as the intended behavior, and it also
174 // involves a copy of the value when it's returned. Many times we're appending
175 // to large lists, and copying the value to discard it for the next statement
177 void ValuePlusEquals(const Scope* scope,
178 const BinaryOpNode* op_node,
179 const Token& left_token,
182 bool allow_type_conversion,
184 switch (left->type()) {
185 // Left-hand-side int.
187 switch (right.type()) {
188 case Value::INTEGER: // int + int -> addition.
189 left->int_value() += right.int_value();
192 case Value::STRING: // int + string -> string concat.
193 if (allow_type_conversion) {
194 *left = Value(op_node,
195 base::Int64ToString(left->int_value()) + right.string_value());
205 // Left-hand-side string.
207 switch (right.type()) {
208 case Value::INTEGER: // string + int -> string concat.
209 left->string_value().append(base::Int64ToString(right.int_value()));
212 case Value::STRING: // string + string -> string contat.
213 left->string_value().append(right.string_value());
221 // Left-hand-side list.
223 switch (right.type()) {
224 case Value::LIST: // list + list -> list concat.
225 if (left_token.value() == kSourcesName) {
226 // Filter additions through the assignment filter.
227 AppendFilteredSourcesToValue(scope, right, left);
229 // Normal list concat.
230 for (const auto& value : right.list_value())
231 left->list_value().push_back(value);
236 *err = Err(op_node->op(), "Incompatible types to add.",
237 "To append a single item to a list do \"foo += [ bar ]\".");
245 *err = Err(op_node->op(), "Incompatible types to add.",
246 std::string("I see a ") + Value::DescribeType(left->type()) + " and a " +
247 Value::DescribeType(right.type()) + ".");
250 Value ExecutePlusEquals(Scope* scope,
251 const BinaryOpNode* op_node,
255 // We modify in-place rather than doing read-modify-write to avoid
256 // copying large lists.
258 scope->GetValueForcedToCurrentScope(left.value(), op_node);
260 *err = Err(left, "Undefined variable for +=.",
261 "I don't have something with this name in scope now.");
264 ValuePlusEquals(scope, op_node, left, left_value, right, false, err);
265 left_value->set_origin(op_node);
266 scope->MarkUnused(left.value());
270 // We return a null value from this rather than the result of doing the append.
271 // See ValuePlusEquals for rationale.
272 void ValueMinusEquals(const BinaryOpNode* op_node,
275 bool allow_type_conversion,
277 switch (left->type()) {
278 // Left-hand-side int.
280 switch (right.type()) {
281 case Value::INTEGER: // int - int -> subtraction.
282 left->int_value() -= right.int_value();
290 // Left-hand-side string.
292 break; // All are errors.
294 // Left-hand-side list.
296 if (right.type() != Value::LIST) {
297 *err = Err(op_node->op(), "Incompatible types to subtract.",
298 "To remove a single item from a list do \"foo -= [ bar ]\".");
300 RemoveMatchesFromList(op_node, left, right, err);
308 *err = Err(op_node->op(), "Incompatible types to subtract.",
309 std::string("I see a ") + Value::DescribeType(left->type()) + " and a " +
310 Value::DescribeType(right.type()) + ".");
313 Value ExecuteMinusEquals(Scope* scope,
314 const BinaryOpNode* op_node,
319 scope->GetValueForcedToCurrentScope(left.value(), op_node);
321 *err = Err(left, "Undefined variable for -=.",
322 "I don't have something with this name in scope now.");
325 ValueMinusEquals(op_node, left_value, right, false, err);
326 left_value->set_origin(op_node);
327 scope->MarkUnused(left.value());
331 // Plus/Minus -----------------------------------------------------------------
333 Value ExecutePlus(Scope* scope,
334 const BinaryOpNode* op_node,
339 ValuePlusEquals(scope, op_node, Token(), &ret, right, true, err);
340 ret.set_origin(op_node);
344 Value ExecuteMinus(Scope* scope,
345 const BinaryOpNode* op_node,
350 ValueMinusEquals(op_node, &ret, right, true, err);
351 ret.set_origin(op_node);
355 // Comparison -----------------------------------------------------------------
357 Value ExecuteEqualsEquals(Scope* scope,
358 const BinaryOpNode* op_node,
363 return Value(op_node, true);
364 return Value(op_node, false);
367 Value ExecuteNotEquals(Scope* scope,
368 const BinaryOpNode* op_node,
372 // Evaluate in terms of ==.
373 Value result = ExecuteEqualsEquals(scope, op_node, left, right, err);
374 result.boolean_value() = !result.boolean_value();
378 Value FillNeedsTwoIntegersError(const BinaryOpNode* op_node,
382 *err = Err(op_node, "Comparison requires two integers.",
383 "This operator can only compare two integers.");
384 err->AppendRange(left.origin()->GetRange());
385 err->AppendRange(right.origin()->GetRange());
389 Value ExecuteLessEquals(Scope* scope,
390 const BinaryOpNode* op_node,
394 if (left.type() != Value::INTEGER || right.type() != Value::INTEGER)
395 return FillNeedsTwoIntegersError(op_node, left, right, err);
396 return Value(op_node, left.int_value() <= right.int_value());
399 Value ExecuteGreaterEquals(Scope* scope,
400 const BinaryOpNode* op_node,
404 if (left.type() != Value::INTEGER || right.type() != Value::INTEGER)
405 return FillNeedsTwoIntegersError(op_node, left, right, err);
406 return Value(op_node, left.int_value() >= right.int_value());
409 Value ExecuteGreater(Scope* scope,
410 const BinaryOpNode* op_node,
414 if (left.type() != Value::INTEGER || right.type() != Value::INTEGER)
415 return FillNeedsTwoIntegersError(op_node, left, right, err);
416 return Value(op_node, left.int_value() > right.int_value());
419 Value ExecuteLess(Scope* scope,
420 const BinaryOpNode* op_node,
424 if (left.type() != Value::INTEGER || right.type() != Value::INTEGER)
425 return FillNeedsTwoIntegersError(op_node, left, right, err);
426 return Value(op_node, left.int_value() < right.int_value());
429 // Binary ----------------------------------------------------------------------
431 Value ExecuteOr(Scope* scope,
432 const BinaryOpNode* op_node,
433 const ParseNode* left_node,
434 const ParseNode* right_node,
436 Value left = GetValueOrFillError(op_node, left_node, "left", scope, err);
437 if (err->has_error())
439 if (left.type() != Value::BOOLEAN) {
440 *err = Err(op_node->left(), "Left side of || operator is not a boolean.",
441 "Type is \"" + std::string(Value::DescribeType(left.type())) +
445 if (left.boolean_value())
446 return Value(op_node, left.boolean_value());
448 Value right = GetValueOrFillError(op_node, right_node, "right", scope, err);
449 if (err->has_error())
451 if (right.type() != Value::BOOLEAN) {
452 *err = Err(op_node->right(), "Right side of || operator is not a boolean.",
453 "Type is \"" + std::string(Value::DescribeType(right.type())) +
458 return Value(op_node, left.boolean_value() || right.boolean_value());
461 Value ExecuteAnd(Scope* scope,
462 const BinaryOpNode* op_node,
463 const ParseNode* left_node,
464 const ParseNode* right_node,
466 Value left = GetValueOrFillError(op_node, left_node, "left", scope, err);
467 if (err->has_error())
469 if (left.type() != Value::BOOLEAN) {
470 *err = Err(op_node->left(), "Left side of && operator is not a boolean.",
471 "Type is \"" + std::string(Value::DescribeType(left.type())) +
475 if (!left.boolean_value())
476 return Value(op_node, left.boolean_value());
478 Value right = GetValueOrFillError(op_node, right_node, "right", scope, err);
479 if (err->has_error())
481 if (right.type() != Value::BOOLEAN) {
482 *err = Err(op_node->right(), "Right side of && operator is not a boolean.",
483 "Type is \"" + std::string(Value::DescribeType(right.type())) +
487 return Value(op_node, left.boolean_value() && right.boolean_value());
492 // ----------------------------------------------------------------------------
494 bool IsUnaryOperator(const Token& token) {
495 return token.type() == Token::BANG;
498 bool IsBinaryOperator(const Token& token) {
499 return token.type() == Token::EQUAL ||
500 token.type() == Token::PLUS ||
501 token.type() == Token::MINUS ||
502 token.type() == Token::PLUS_EQUALS ||
503 token.type() == Token::MINUS_EQUALS ||
504 token.type() == Token::EQUAL_EQUAL ||
505 token.type() == Token::NOT_EQUAL ||
506 token.type() == Token::LESS_EQUAL ||
507 token.type() == Token::GREATER_EQUAL ||
508 token.type() == Token::LESS_THAN ||
509 token.type() == Token::GREATER_THAN ||
510 token.type() == Token::BOOLEAN_AND ||
511 token.type() == Token::BOOLEAN_OR;
514 bool IsFunctionCallArgBeginScoper(const Token& token) {
515 return token.type() == Token::LEFT_PAREN;
518 bool IsFunctionCallArgEndScoper(const Token& token) {
519 return token.type() == Token::RIGHT_PAREN;
522 bool IsScopeBeginScoper(const Token& token) {
523 return token.type() == Token::LEFT_BRACE;
526 bool IsScopeEndScoper(const Token& token) {
527 return token.type() == Token::RIGHT_BRACE;
530 Value ExecuteUnaryOperator(Scope* scope,
531 const UnaryOpNode* op_node,
534 DCHECK(op_node->op().type() == Token::BANG);
536 if (expr.type() != Value::BOOLEAN) {
537 *err = Err(op_node, "Operand of ! operator is not a boolean.",
538 "Type is \"" + std::string(Value::DescribeType(expr.type())) +
542 // TODO(scottmg): Why no unary minus?
543 return Value(op_node, !expr.boolean_value());
546 Value ExecuteBinaryOperator(Scope* scope,
547 const BinaryOpNode* op_node,
548 const ParseNode* left,
549 const ParseNode* right,
551 const Token& op = op_node->op();
553 // First handle the ones that take an lvalue.
554 if (op.type() == Token::EQUAL ||
555 op.type() == Token::PLUS_EQUALS ||
556 op.type() == Token::MINUS_EQUALS) {
557 const IdentifierNode* left_id = left->AsIdentifier();
559 *err = Err(op, "Operator requires a lvalue.",
560 "This thing on the left is not an identifier.");
561 err->AppendRange(left->GetRange());
564 const Token& dest = left_id->value();
566 Value right_value = right->Execute(scope, err);
567 if (err->has_error())
569 if (right_value.type() == Value::NONE) {
570 *err = Err(op, "Operator requires a rvalue.",
571 "This thing on the right does not evaluate to a value.");
572 err->AppendRange(right->GetRange());
576 if (op.type() == Token::EQUAL)
577 return ExecuteEquals(scope, op_node, dest, right_value, err);
578 if (op.type() == Token::PLUS_EQUALS)
579 return ExecutePlusEquals(scope, op_node, dest, right_value, err);
580 if (op.type() == Token::MINUS_EQUALS)
581 return ExecuteMinusEquals(scope, op_node, dest, right_value, err);
586 // ||, &&. Passed the node instead of the value so that they can avoid
587 // evaluating the RHS on early-out.
588 if (op.type() == Token::BOOLEAN_OR)
589 return ExecuteOr(scope, op_node, left, right, err);
590 if (op.type() == Token::BOOLEAN_AND)
591 return ExecuteAnd(scope, op_node, left, right, err);
593 Value left_value = GetValueOrFillError(op_node, left, "left", scope, err);
594 if (err->has_error())
596 Value right_value = GetValueOrFillError(op_node, right, "right", scope, err);
597 if (err->has_error())
601 if (op.type() == Token::MINUS)
602 return ExecuteMinus(scope, op_node, left_value, right_value, err);
603 if (op.type() == Token::PLUS)
604 return ExecutePlus(scope, op_node, left_value, right_value, err);
607 if (op.type() == Token::EQUAL_EQUAL)
608 return ExecuteEqualsEquals(scope, op_node, left_value, right_value, err);
609 if (op.type() == Token::NOT_EQUAL)
610 return ExecuteNotEquals(scope, op_node, left_value, right_value, err);
611 if (op.type() == Token::GREATER_EQUAL)
612 return ExecuteGreaterEquals(scope, op_node, left_value, right_value, err);
613 if (op.type() == Token::LESS_EQUAL)
614 return ExecuteLessEquals(scope, op_node, left_value, right_value, err);
615 if (op.type() == Token::GREATER_THAN)
616 return ExecuteGreater(scope, op_node, left_value, right_value, err);
617 if (op.type() == Token::LESS_THAN)
618 return ExecuteLess(scope, op_node, left_value, right_value, err);