CLI

This document describes the command line interface for the project. Reading both about the parser specification format and the semantics of the backends is most likely needed in order to understand what the commands are doing.

1 Overview

Invoking MBCC takes takes on 2 distinct forms, commands calculating information about a grammar/parser specification, and commands that are actually outputting the parser.

There are however a couple of options that are common between these 2 modes.

All invocations require a parser specification file to operate, and is provided as the first argument.

Options that specify the type of parser are also common, as they determine which kind of checks that should be made, aswell as what kind of parser to create.

2 Parser type options

These options determine the properties of the outputted parser

2.1 Argument options

2.1.1 k

Specifies how many tokens of lookahead that should be used when creating a deterministic parser with fixed lookahead. The default value is 1.

Providing a string that can't be parsed as an positive integer terminates the program with a failing exit status, and no files are modified.

3 Invocations

The invocations are separated by the inclusion of the "verify" flag. If this flag is included, only verification is performed, and no output files need to be provided. It also enables the inclusion of verification options, which determine which kind of checks should be performed. The exclusion of this flag instead invokes the creation step, where verification options become invalid.

3.1 Verification

mbcc --verify {ParseSpecificationFile} <Parser type options> <Verification options>

3.2 Creation

mbcc {ParseSpecificationFile} <Parser type options> -h:{OutHeader} -s:{OutSorce} -t:{TargetLangauge=c++}

The exclusion of either the header,source, or parser specification file or and invalid target language terminates the program with a failing exit status, and no files are modified.

A invalid parse specification also terminates the program with a fatal error, and no files are modified.

If all files are provided, the program not being able to open the output files for writing or the parser specification file for reading also terminates the program with a fatal error.

The grammar is then verified with the default checks that are appropriate for the parser as specified by the parser type options. If the provided parser specification fails any of these checks, so is the program terminated with a fatal error and no output files are modified.

After all of the previous mentioned steps are executed, the output files are opened, and the parser is written.