arangodb/arangod/Aql/Parser.cpp

////////////////////////////////////////////////////////////////////////////////
/// @brief Aql, query parser
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2012-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "Aql/Parser.h"
#include "Aql/AstNode.h"
#include "Aql/QueryResult.h"

using namespace triagens::aql;

// -----------------------------------------------------------------------------
// --SECTION--                                        constructors / destructors
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief create the parser
////////////////////////////////////////////////////////////////////////////////

Parser::Parser (Query* query)
  : _query(query),
    _ast(nullptr),
    _scanner(nullptr),
    _buffer(query->queryString()),
    _remainingLength(query->queryLength()),
    _offset(0),
    _marker(nullptr),
    _stack() {
  
  _ast = new Ast(query, this);

  _stack.reserve(16);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief destroy the parser
////////////////////////////////////////////////////////////////////////////////

Parser::~Parser () {
  if (_ast != nullptr) {
    delete _ast;
  }
}

// -----------------------------------------------------------------------------
// --SECTION--                                                  public functions
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @brief set data for write queries
////////////////////////////////////////////////////////////////////////////////

bool Parser::configureWriteQuery (QueryType type,
                                  AstNode const* collectionNode,
                                  AstNode* optionNode) {
  TRI_ASSERT(type != AQL_QUERY_READ);

  // check if we currently are in a subquery
  if (_ast->isInSubQuery()) {
    // data modification not allowed in sub-queries
    _query->registerError(TRI_ERROR_QUERY_MODIFY_IN_SUBQUERY);
    return false;
  }

  // check current query type
  auto oldType = _query->type();

  if (oldType != AQL_QUERY_READ) {
    // already a data-modification query, cannot have two data-modification operations in one query
    _query->registerError(TRI_ERROR_QUERY_MULTI_MODIFY);
    return false;
  }

  // now track which collection is going to be modified
  _ast->setWriteCollection(collectionNode);
  _ast->setWriteOptions(optionNode);

  // register type 
  _query->type(type);
  return true;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief parse the query
////////////////////////////////////////////////////////////////////////////////

QueryResult Parser::parse () {
  // start main scope
  auto scopes = _ast->scopes();
  scopes->start(AQL_SCOPE_MAIN);
  
  Aqllex_init(&_scanner);
  Aqlset_extra(this, _scanner);

  try {
    // parse the query string
    if (Aqlparse(this)) {
      // lexing/parsing failed
      THROW_ARANGO_EXCEPTION(TRI_ERROR_QUERY_PARSE);
    }

    Aqllex_destroy(_scanner);
  }
  catch (...) {
    Aqllex_destroy(_scanner);
    throw;
  }

  // end main scope
  scopes->endCurrent();

  TRI_ASSERT(scopes->numActive() == 0);

  QueryResult result;
  result.collectionNames = _query->collectionNames();
  result.bindParameters  = _ast->bindParameters();
  result.json            = _ast->toJson(TRI_UNKNOWN_MEM_ZONE);

  return result;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief register a parse error, position is specified as line / column
////////////////////////////////////////////////////////////////////////////////

void Parser::registerParseError (char const* format,
                                 char const* data,
                                 int line,
                                 int column) {
  char buffer[512];
  snprintf(buffer,
           sizeof(buffer),
           format,
           data);

  return registerParseError(buffer, line, column);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief register a parse error, position is specified as line / column
////////////////////////////////////////////////////////////////////////////////

void Parser::registerParseError (char const* data,
                                 int line,
                                 int column) {
  TRI_ASSERT(data != nullptr);

  // extract the query string part where the error happened
  std::string const region(_query->extractRegion(line, column));

  // note: line numbers reported by bison/flex start at 1, columns start at 0
  char buffer[512];
  snprintf(buffer,
           sizeof(buffer),
           "%s near '%s' at position %d:%d",
           data,
           region.c_str(),
           line,
           column + 1);

  registerError(TRI_ERROR_QUERY_PARSE, buffer);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief register a non-parse error
////////////////////////////////////////////////////////////////////////////////

void Parser::registerError (int errorCode,
                            char const* data) {
  _query->registerError(errorCode, data);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief push an AstNode into the list element on top of the stack
////////////////////////////////////////////////////////////////////////////////

void Parser::pushList (AstNode* node) {
  auto list = static_cast<AstNode*>(peekStack());
  TRI_ASSERT(list->type == NODE_TYPE_LIST);
  list->addMember(node);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief push an AstNode into the array element on top of the stack
////////////////////////////////////////////////////////////////////////////////

void Parser::pushArray (char const* attributeName,
                        AstNode* node) {
  auto array = static_cast<AstNode*>(peekStack());
  TRI_ASSERT(array->type == NODE_TYPE_ARRAY);
  auto element = _ast->createNodeArrayElement(attributeName, node);
  array->addMember(element);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief push a temporary value on the parser's stack
////////////////////////////////////////////////////////////////////////////////

void Parser::pushStack (void* value) {
  _stack.push_back(value);
}

////////////////////////////////////////////////////////////////////////////////
/// @brief pop a temporary value from the parser's stack
////////////////////////////////////////////////////////////////////////////////
        
void* Parser::popStack () {
  TRI_ASSERT(! _stack.empty());

  void* result = _stack.back();
  _stack.pop_back();
  return result;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief peek at a temporary value from the parser's stack
////////////////////////////////////////////////////////////////////////////////
        
void* Parser::peekStack () {
  TRI_ASSERT(! _stack.empty());

  return _stack.back();
}

// -----------------------------------------------------------------------------
// --SECTION--                                                       END-OF-FILE
// -----------------------------------------------------------------------------

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