Developer Documentation

Basic Requirements

Requirements for development:

gcc 4.8+ (or clang 3.4+)
bison (v3.0.2+)
flex (v2.5.5+)

First step to extending this parser is cloning the repository git clone git@github.com:hyrise/sql-parser.git and making sure everything works by running the following steps:

make parser   # builds the bison parser and flex lexer
make library  # builds the libsqlparser.so
make test     # runs the tests with the library

Rerun these steps whenever you change part of the parse. To execute the entire pipeline automatically you can run:

make cleanall  # cleans the parser build and library build
make test      # build parser, library and runs the tests

Developing New Functionality

This section contains information about how to extend this parser with new functionalities.

Implementing a new Statement

Create a new file and class in src/sql/ or extend any of the existing Statements. Every statement needs to have the base class SQLStatement and needs to call its super constructor with its type. If you're defining a new statement type, you need to define a new StatementType in SQLStatement.h.

It is important that you create an appropriate constructor for your statement that zero-initializes all its pointer variables and that you create an appropriate destructor.

Finally you will need to include your new file in src/sql/statements.h.

Extending the Grammar

Related files:

src/parser/bison_parser.y
src/parser/flex_lexer.l
src/parser/keywordlist_generator.py
src/parser/sql_keywords.txt

To extend the grammar the file you will mostly have to deal with is the bison grammar definition in src/parser/bison_parser.y.

If you're extending an existing statement, skip to the non-terminal definition for that statement. I.e. for an InsertStatement the non-terminal insert_statement.

If you're defining a new statement, you will need to define your type in the %union directive hsql::ExampleStatement example_stmt. Next you need to associate this type with a non-terminal \%type <example_stmt> example_statement. Then you have to define the non-terminal example_statement. Look the other non-terminals for statements to figure out how.

Implementing Tests

All test related files are in test/. Take a look to see how tests are implemented.

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