YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

//--------------------------------------------------------------------------------------------------

// Copyright (c) YugaByte, Inc.

//

// 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.

//

//

// Entry point for the parsing process. Conducting the whole scanning and parsing of SQL statement.

//--------------------------------------------------------------------------------------------------

#ifndef YB_YQL_CQL_QL_PARSER_PARSER_H_

#define YB_YQL_CQL_QL_PARSER_PARSER_H_

#include <cstddef>

#include "yb/yql/cql/ql/parser/parse_context.h"

#include "yb/yql/cql/ql/parser/scanner.h"

#include "yb/yql/cql/ql/util/errcodes.h"

#include "yb/util/memory/arena.h"

namespace yb {

namespace ql {

class Parser {

 public:

  //------------------------------------------------------------------------------------------------

  // Public types.

  typedef std::unique_ptr<Parser> UniPtr;

  typedef std::unique_ptr<const Parser> UniPtrConst;

  //------------------------------------------------------------------------------------------------

  // Constructor & destructor.

  Parser();

  virtual ~Parser();

  // Returns 0 if Bison successfully parses SQL statements, and the compiler can continue on to

  // semantic analysis. Otherwise, it returns one of the errcodes that are defined in file

  // "yb/yql/cql/ql/errcodes.h", and the caller (QL API) should stop the compiling process.

  CHECKED_STATUS Parse(const std::string& stmt, bool reparsed,

                       const MemTrackerPtr& mem_tracker = nullptr, const bool internal = false);

  // Returns the generated parse tree.

  ParseTree::UniPtr Done();

  // Entry function to scan the next token. Bison parser will call this function.

  GramProcessor::symbol_type Scan();

  // Saves the generated parse tree from the parsing process.

  void SaveGeneratedParseTree(TreeNode::SharedPtr generated_parse_tree) {

    parse_context_->SaveGeneratedParseTree(generated_parse_tree);

  }

  // Add a bind variable.

  void AddBindVariable(PTBindVar *var) {

    parse_context_->AddBindVariable(var);

  }

  // Set the list of bind variables found during parsing in a DML statement.

  void SetBindVariables(PTDmlStmt *stmt) {

    parse_context_->GetBindVariables(&stmt->bind_variables());

  }

  // Access function for parse_context_.

  ParseContext *parse_context() const {

    return parse_context_.get();

  }

  // Converts a char* to MCString.

  MCSharedPtr<MCString> MakeString(const char *str) {

    return MCMakeShared<MCString>(PTreeMem(), str);

  }

  // Memory pool for allocating and deallocating operating memory spaces during parsing process.

  MemoryContext *PTempMem() const {

    return parse_context_->PTempMem();

  }

  // Memory pool for constructing the parse tree of a statement. This context will have the same

  // lifetime as the parse tree.

  MemoryContext *PTreeMem() const {

    return parse_context_->PTreeMem();

  }

  // Raise parsing error.

  void Error(const location& loc, ErrorCode error_code) {

    // Bison parser will raise exception, so we don't return Status::Error here.

    Status s = parse_context_->Error(loc, error_code);

    VLOG(3) << s.ToString();

  }

  void Error(const location& loc, const char *msg, ErrorCode error_code) {

    // Bison parser will raise exception, so we don't return Status::Error here.

    Status s = parse_context_->Error(loc, msg, error_code);

    VLOG(3) << s.ToString();

  }

 private:

  //------------------------------------------------------------------------------------------------

  // Parse context which consists of state variables and results.

  // NOTE: parse context must be FIRST class field to be destroyed by the class destructor

  //       after all other dependent class fields (e.g. processors below).

  ParseContext::UniPtr parse_context_;

  // Lexical scanner.

  LexProcessor lex_processor_;

  // Grammar parser.

  GramProcessor gram_processor_;

};

}  // namespace ql

}  // namespace yb

#endif  // YB_YQL_CQL_QL_PARSER_PARSER_H_