tools/gn/parse

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
IndentFor
AsAccessor
AsBinaryOp
AsBlock
AsConditionNode
AsFunctionCall
AsIdentifier
AsList
AsLiteral
AsUnaryOp
AsAccessor
Execute
GetRange
MakeErrorDescribing
Print
ExecuteArrayAccess
ExecuteScopeAccess
AsBinaryOp
Execute
GetRange
MakeErrorDescribing
Print
AsBlock
Execute
GetRange
MakeErrorDescribing
Print
ExecuteBlockInScope
AsConditionNode
Execute
GetRange
MakeErrorDescribing
Print
AsFunctionCall
Execute
GetRange
MakeErrorDescribing
Print
AsIdentifier
Execute
GetRange
MakeErrorDescribing
Print
AsList
Execute
GetRange
MakeErrorDescribing
Print
AsLiteral
Execute
GetRange
MakeErrorDescribing
Print
AsUnaryOp
Execute
GetRange
MakeErrorDescribing
Print
// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "tools/gn/parse_tree.h"

#include <string>

#include "base/stl_util.h"
#include "base/strings/string_number_conversions.h"
#include "tools/gn/functions.h"
#include "tools/gn/operators.h"
#include "tools/gn/scope.h"
#include "tools/gn/string_utils.h"

namespace {

std::string IndentFor(int value) {
  std::string ret;
  for (int i = 0; i < value; i++)
    ret.append(" ");
  return ret;
}

}  // namespace

ParseNode::ParseNode() {
}

ParseNode::~ParseNode() {
}

const AccessorNode* ParseNode::AsAccessor() const { return NULL; }
const BinaryOpNode* ParseNode::AsBinaryOp() const { return NULL; }
const BlockNode* ParseNode::AsBlock() const { return NULL; }
const ConditionNode* ParseNode::AsConditionNode() const { return NULL; }
const FunctionCallNode* ParseNode::AsFunctionCall() const { return NULL; }
const IdentifierNode* ParseNode::AsIdentifier() const { return NULL; }
const ListNode* ParseNode::AsList() const { return NULL; }
const LiteralNode* ParseNode::AsLiteral() const { return NULL; }
const UnaryOpNode* ParseNode::AsUnaryOp() const { return NULL; }

// AccessorNode ---------------------------------------------------------------

AccessorNode::AccessorNode() {
}

AccessorNode::~AccessorNode() {
}

const AccessorNode* AccessorNode::AsAccessor() const {
  return this;
}

Value AccessorNode::Execute(Scope* scope, Err* err) const {
  if (index_)
    return ExecuteArrayAccess(scope, err);
  else if (member_)
    return ExecuteScopeAccess(scope, err);
  NOTREACHED();
  return Value();
}

LocationRange AccessorNode::GetRange() const {
  if (index_)
    return LocationRange(base_.location(), index_->GetRange().end());
  else if (member_)
    return LocationRange(base_.location(), member_->GetRange().end());
  NOTREACHED();
  return LocationRange();
}

Err AccessorNode::MakeErrorDescribing(const std::string& msg,
                                      const std::string& help) const {
  return Err(GetRange(), msg, help);
}

void AccessorNode::Print(std::ostream& out, int indent) const {
  out << IndentFor(indent) << "ACCESSOR\n";
  out << IndentFor(indent + 1) << base_.value() << "\n";
  if (index_)
    index_->Print(out, indent + 1);
  else if (member_)
    member_->Print(out, indent + 1);
}

Value AccessorNode::ExecuteArrayAccess(Scope* scope, Err* err) const {
  Value index_value = index_->Execute(scope, err);
  if (err->has_error())
    return Value();
  if (!index_value.VerifyTypeIs(Value::INTEGER, err))
    return Value();

  const Value* base_value = scope->GetValue(base_.value(), true);
  if (!base_value) {
    *err = MakeErrorDescribing("Undefined identifier.");
    return Value();
  }
  if (!base_value->VerifyTypeIs(Value::LIST, err))
    return Value();

  int64 index_int = index_value.int_value();
  if (index_int < 0) {
    *err = Err(index_->GetRange(), "Negative array subscript.",
        "You gave me " + base::Int64ToString(index_int) + ".");
    return Value();
  }
  size_t index_sizet = static_cast<size_t>(index_int);
  if (index_sizet >= base_value->list_value().size()) {
    *err = Err(index_->GetRange(), "Array subscript out of range.",
        "You gave me " + base::Int64ToString(index_int) +
        " but I was expecting something from 0 to " +
        base::Int64ToString(
            static_cast<int64>(base_value->list_value().size()) - 1) +
        ", inclusive.");
    return Value();
  }

  // Doing this assumes that there's no way in the language to do anything
  // between the time the reference is created and the time that the reference
  // is used. If there is, this will crash! Currently, this is just used for
  // array accesses where this "shouldn't" happen.
  return base_value->list_value()[index_sizet];
}

Value AccessorNode::ExecuteScopeAccess(Scope* scope, Err* err) const {
  // We jump through some hoops here since ideally a.b will count "b" as
  // accessed in the given scope. The value "a" might be in some normal nested
  // scope and we can modify it, but it might also be inherited from the
  // readonly root scope and we can't do used variable tracking on it. (It's
  // not legal to const cast it away since the root scope will be in readonly
  // mode and being accessed from multiple threads without locking.) So this
  // code handles both cases.
  const Value* result = NULL;

  // Look up the value in the scope named by "base_".
  Value* mutable_base_value = scope->GetMutableValue(base_.value(), true);
  if (mutable_base_value) {
    // Common case: base value is mutable so we can track variable accesses
    // for unused value warnings.
    if (!mutable_base_value->VerifyTypeIs(Value::SCOPE, err))
      return Value();
    result = mutable_base_value->scope_value()->GetValue(
        member_->value().value(), true);
  } else {
    // Fall back to see if the value is on a read-only scope.
    const Value* const_base_value = scope->GetValue(base_.value(), true);
    if (const_base_value) {
      // Read only value, don't try to mark the value access as a "used" one.
      if (!const_base_value->VerifyTypeIs(Value::SCOPE, err))
        return Value();
      result =
          const_base_value->scope_value()->GetValue(member_->value().value());
    } else {
      *err = Err(base_, "Undefined identifier.");
      return Value();
    }
  }

  if (!result) {
    *err = Err(member_.get(), "No value named \"" +
        member_->value().value() + "\" in scope \"" + base_.value() + "\"");
    return Value();
  }
  return *result;
}

// BinaryOpNode ---------------------------------------------------------------

BinaryOpNode::BinaryOpNode() {
}

BinaryOpNode::~BinaryOpNode() {
}

const BinaryOpNode* BinaryOpNode::AsBinaryOp() const {
  return this;
}

Value BinaryOpNode::Execute(Scope* scope, Err* err) const {
  return ExecuteBinaryOperator(scope, this, left_.get(), right_.get(), err);
}

LocationRange BinaryOpNode::GetRange() const {
  return left_->GetRange().Union(right_->GetRange());
}

Err BinaryOpNode::MakeErrorDescribing(const std::string& msg,
                                      const std::string& help) const {
  return Err(op_, msg, help);
}

void BinaryOpNode::Print(std::ostream& out, int indent) const {
  out << IndentFor(indent) << "BINARY(" << op_.value() << ")\n";
  left_->Print(out, indent + 1);
  right_->Print(out, indent + 1);
}

// BlockNode ------------------------------------------------------------------

BlockNode::BlockNode(bool has_scope) : has_scope_(has_scope) {
}

BlockNode::~BlockNode() {
  STLDeleteContainerPointers(statements_.begin(), statements_.end());
}

const BlockNode* BlockNode::AsBlock() const {
  return this;
}

Value BlockNode::Execute(Scope* containing_scope, Err* err) const {
  if (has_scope_) {
    Scope our_scope(containing_scope);
    Value ret = ExecuteBlockInScope(&our_scope, err);
    if (err->has_error())
      return Value();

    // Check for unused vars in the scope.
    //our_scope.CheckForUnusedVars(err);
    return ret;
  }
  return ExecuteBlockInScope(containing_scope, err);
}

LocationRange BlockNode::GetRange() const {
  if (begin_token_.type() != Token::INVALID &&
      end_token_.type() != Token::INVALID) {
    return begin_token_.range().Union(end_token_.range());
  } else if (!statements_.empty()) {
    return statements_[0]->GetRange().Union(
        statements_[statements_.size() - 1]->GetRange());
  }
  return LocationRange();
}

Err BlockNode::MakeErrorDescribing(const std::string& msg,
                                   const std::string& help) const {
  return Err(GetRange(), msg, help);
}

void BlockNode::Print(std::ostream& out, int indent) const {
  out << IndentFor(indent) << "BLOCK\n";
  for (size_t i = 0; i < statements_.size(); i++)
    statements_[i]->Print(out, indent + 1);
}

Value BlockNode::ExecuteBlockInScope(Scope* our_scope, Err* err) const {
  for (size_t i = 0; i < statements_.size() && !err->has_error(); i++) {
    // Check for trying to execute things with no side effects in a block.
    const ParseNode* cur = statements_[i];
    if (cur->AsList() || cur->AsLiteral() || cur->AsUnaryOp() ||
        cur->AsIdentifier()) {
      *err = cur->MakeErrorDescribing(
          "This statement has no effect.",
          "Either delete it or do something with the result.");
      return Value();
    }
    cur->Execute(our_scope, err);
  }
  return Value();
}

// ConditionNode --------------------------------------------------------------

ConditionNode::ConditionNode() {
}

ConditionNode::~ConditionNode() {
}

const ConditionNode* ConditionNode::AsConditionNode() const {
  return this;
}

Value ConditionNode::Execute(Scope* scope, Err* err) const {
  Value condition_result = condition_->Execute(scope, err);
  if (err->has_error())
    return Value();
  if (condition_result.type() != Value::BOOLEAN) {
    *err = condition_->MakeErrorDescribing(
        "Condition does not evaluate to a boolean value.",
        std::string("This is a value of type \"") +
            Value::DescribeType(condition_result.type()) +
            "\" instead.");
    err->AppendRange(if_token_.range());
    return Value();
  }

  if (condition_result.boolean_value()) {
    if_true_->ExecuteBlockInScope(scope, err);
  } else if (if_false_) {
    // The else block is optional. It's either another condition (for an
    // "else if" and we can just Execute it and the condition will handle
    // the scoping) or it's a block indicating an "else" in which ase we
    // need to be sure it inherits our scope.
    const BlockNode* if_false_block = if_false_->AsBlock();
    if (if_false_block)
      if_false_block->ExecuteBlockInScope(scope, err);
    else
      if_false_->Execute(scope, err);
  }

  return Value();
}

LocationRange ConditionNode::GetRange() const {
  if (if_false_)
    return if_token_.range().Union(if_false_->GetRange());
  return if_token_.range().Union(if_true_->GetRange());
}

Err ConditionNode::MakeErrorDescribing(const std::string& msg,
                                       const std::string& help) const {
  return Err(if_token_, msg, help);
}

void ConditionNode::Print(std::ostream& out, int indent) const {
  out << IndentFor(indent) << "CONDITION\n";
  condition_->Print(out, indent + 1);
  if_true_->Print(out, indent + 1);
  if (if_false_)
    if_false_->Print(out, indent + 1);
}

// FunctionCallNode -----------------------------------------------------------

FunctionCallNode::FunctionCallNode() {
}

FunctionCallNode::~FunctionCallNode() {
}

const FunctionCallNode* FunctionCallNode::AsFunctionCall() const {
  return this;
}

Value FunctionCallNode::Execute(Scope* scope, Err* err) const {
  return functions::RunFunction(scope, this, args_.get(), block_.get(), err);
}

LocationRange FunctionCallNode::GetRange() const {
  if (block_)
    return function_.range().Union(block_->GetRange());
  return function_.range().Union(args_->GetRange());
}

Err FunctionCallNode::MakeErrorDescribing(const std::string& msg,
                                          const std::string& help) const {
  return Err(function_, msg, help);
}

void FunctionCallNode::Print(std::ostream& out, int indent) const {
  out << IndentFor(indent) << "FUNCTION(" << function_.value() << ")\n";
  args_->Print(out, indent + 1);
  if (block_)
    block_->Print(out, indent + 1);
}

// IdentifierNode --------------------------------------------------------------

IdentifierNode::IdentifierNode() {
}

IdentifierNode::IdentifierNode(const Token& token) : value_(token) {
}

IdentifierNode::~IdentifierNode() {
}

const IdentifierNode* IdentifierNode::AsIdentifier() const {
  return this;
}

Value IdentifierNode::Execute(Scope* scope, Err* err) const {
  const Value* result = scope->GetValue(value_.value(), true);
  if (!result) {
    *err = MakeErrorDescribing("Undefined identifier");
    return Value();
  }
  return *result;
}

LocationRange IdentifierNode::GetRange() const {
  return value_.range();
}

Err IdentifierNode::MakeErrorDescribing(const std::string& msg,
                                        const std::string& help) const {
  return Err(value_, msg, help);
}

void IdentifierNode::Print(std::ostream& out, int indent) const {
  out << IndentFor(indent) << "IDENTIFIER(" << value_.value() << ")\n";
}

// ListNode -------------------------------------------------------------------

ListNode::ListNode() {
}

ListNode::~ListNode() {
  STLDeleteContainerPointers(contents_.begin(), contents_.end());
}

const ListNode* ListNode::AsList() const {
  return this;
}

Value ListNode::Execute(Scope* scope, Err* err) const {
  Value result_value(this, Value::LIST);
  std::vector<Value>& results = result_value.list_value();
  results.resize(contents_.size());

  for (size_t i = 0; i < contents_.size(); i++) {
    const ParseNode* cur = contents_[i];
    results[i] = cur->Execute(scope, err);
    if (err->has_error())
      return Value();
    if (results[i].type() == Value::NONE) {
      *err = cur->MakeErrorDescribing(
          "This does not evaluate to a value.",
          "I can't do something with nothing.");
      return Value();
    }
  }
  return result_value;
}

LocationRange ListNode::GetRange() const {
  return LocationRange(begin_token_.location(), end_token_.location());
}

Err ListNode::MakeErrorDescribing(const std::string& msg,
                                  const std::string& help) const {
  return Err(begin_token_, msg, help);
}

void ListNode::Print(std::ostream& out, int indent) const {
  out << IndentFor(indent) << "LIST\n";
  for (size_t i = 0; i < contents_.size(); i++)
    contents_[i]->Print(out, indent + 1);
}

// LiteralNode -----------------------------------------------------------------

LiteralNode::LiteralNode() {
}

LiteralNode::LiteralNode(const Token& token) : value_(token) {
}

LiteralNode::~LiteralNode() {
}

const LiteralNode* LiteralNode::AsLiteral() const {
  return this;
}

Value LiteralNode::Execute(Scope* scope, Err* err) const {
  switch (value_.type()) {
    case Token::TRUE_TOKEN:
      return Value(this, true);
    case Token::FALSE_TOKEN:
      return Value(this, false);
    case Token::INTEGER: {
      int64 result_int;
      if (!base::StringToInt64(value_.value(), &result_int)) {
        *err = MakeErrorDescribing("This does not look like an integer");
        return Value();
      }
      return Value(this, result_int);
    }
    case Token::STRING: {
      Value v(this, Value::STRING);
      ExpandStringLiteral(scope, value_, &v, err);
      return v;
    }
    default:
      NOTREACHED();
      return Value();
  }
}

LocationRange LiteralNode::GetRange() const {
  return value_.range();
}

Err LiteralNode::MakeErrorDescribing(const std::string& msg,
                                     const std::string& help) const {
  return Err(value_, msg, help);
}

void LiteralNode::Print(std::ostream& out, int indent) const {
  out << IndentFor(indent) << "LITERAL(" << value_.value() << ")\n";
}

// UnaryOpNode ----------------------------------------------------------------

UnaryOpNode::UnaryOpNode() {
}

UnaryOpNode::~UnaryOpNode() {
}

const UnaryOpNode* UnaryOpNode::AsUnaryOp() const {
  return this;
}

Value UnaryOpNode::Execute(Scope* scope, Err* err) const {
  Value operand_value = operand_->Execute(scope, err);
  if (err->has_error())
    return Value();
  return ExecuteUnaryOperator(scope, this, operand_value, err);
}

LocationRange UnaryOpNode::GetRange() const {
  return op_.range().Union(operand_->GetRange());
}

Err UnaryOpNode::MakeErrorDescribing(const std::string& msg,
                                     const std::string& help) const {
  return Err(op_, msg, help);
}

void UnaryOpNode::Print(std::ostream& out, int indent) const {
  out << IndentFor(indent) << "UNARY(" << op_.value() << ")\n";
  operand_->Print(out, indent + 1);
}
/* [<][>][^][v][top][bottom][index][help] */
root/tools/gn/parse_tree.cc

DEFINITIONS
