1// Main page documentation for ANTLR3C runtime. Contains 2// doxygen things only. 3// 4 5/// \mainpage ANTLR3 C Runtime API and Usage Guide. 6/// 7/// \section version Version 3.3.1 8/// 9/// This documentation is specifically for the C rutime version 3.1.x.x, which is 10/// specifically for use with version 3.1.x.x of the ANTLR recognizer generation 11/// tool. While some of the documentation may well apply to prior or future versions 12/// you should consult the manuals for the correct version whenever possible. 13/// 14/// \section chchchchangeesss Changes from 3.2 to 3.3.1 15/// 16/// Some changes in 3.3.1 may require small changes in your invoking programs or 17/// in the grammar itself. Please read about them here before emailing the user group, 18/// where you will be told to come and read about them here, unless they were missed 19/// from this list. 20/// 21/// - \subpage changes331 Check here for API changes 22/// 23/// \section intro Introduction 24/// 25/// The ANTLR3 recognizer generation tool is written in Java, but allows the generation 26/// of code targeted for a number of other languages. Each target language provides a code 27/// generation template for the tool and a runtime library for use by generated recognizers. 28/// The C runtime tracks the Java runtime releases and in general when a new version of the 29/// tool is released, a new version of the C runtime will be released at the same time. 30/// 31/// The documentation here is in three parts: 32/// 33/// - \subpage build Building the runtime itself from source code; 34/// - \subpage generate How to tell ANTLR to generate code for the C target; 35/// - \subpage buildrec How to build the generated code 36/// - \subpage using Using the runtime and the libraries and so on; 37/// - \subpage runtime The documentation of the runtime code and functions; 38/// 39/// \section background Background Information 40/// 41/// The ANTLR 3 C runtime and code generation templates were written by <a href="http://www.linkedin.com/in/jimidle"> Jim Idle</a> 42/// (jimi|at|temporal-wave|dott/com) of <a href="http://www.temporal-wave.com">Temporal Wave LLC</a>. 43/// 44/// The C runtime and therefore the code generated to utilize the runtime reflects the object model of the 45/// Java version of the runtime as closely as a language without class structures and inheritance can. 46/// Compromises have only been made where performance would be adversely affected such as minimizing the 47/// number of pointer to pointer to pointer to function type structures that could ensue through trying to 48/// model inheritance too exactly. Other differences include the use of token and string factories to minimize 49/// the number of calls to system functions such as calloc().This model was adopted so that overriding any 50/// default implementation of a function is relatively simple for the grammar programmer. 51/// 52/// The generated code is free threading (subject to the systems calls used on any particular platform 53/// being likewise free threading.) 54/// 55/// \subsection model Runtime Model 56/// 57/// As there is no such thing as an object reference in C, the runtime defines a number of typedef structs that reflect 58/// the calling interface chosen by Terence Parr for the Java version of the same. The initialization of a parser, 59/// lexer, input stream or other internal structure therefore consists of allocating the memory required for 60/// an instance of the typedef struct that represents the interface, initializing any counters, and buffers etc, 61/// then populating a number of pointers to functions that implement the equivalent of the methods in the Java class. 62/// 63/// The use and initialization of the C versions of a parser is therefore similar to the examples given for Java, 64/// but with a bent towards C of course. You may need to be aware of memory allocation and freeing operations 65/// in certain environments such as Windows, where you cannot allocate memory in one DLL and free it in another. 66/// 67/// The runtime provides a number of structures and interfaces that the author has found useful when writing action and 68/// processing code within java parsers, and furthermore were required by the C runtime code if it was not to 69/// depart too far from the logical layout of the Java model. These include the C equivalents of String, List, 70/// Hashtable, Vector and Trie, implemented by pointers to structures. These are freely available for your own programming needs. 71/// 72/// A goal of the generated code was to minimize the tracking, allocation and freeing of memory for reasons of both 73/// performance and reliability. In essence any memory used by a lexer, parser or tree parser is automatically tracked and 74/// freed when the instance of it is released. There are therefore factory functions for tokens and so on such that they 75/// can be allocated in blocks and parceled out as they are required. They are all then freed in one go, minimizing the 76/// risk of memory leaks and alloc/free thrashing. This has only one side effect, being that if you wish to preserve some structure generated by 77/// the lexer, parser or tree parser, then you must make a copy of it before freeing those structures, and track it yourself 78/// after that. In practice, it is easy enough just not to release the antlr generated components until you are 79/// finished with their results. 80/// 81/// \section targets Target Platforms 82/// 83/// The C project is constructed such that it will compile on any reasonable ANSI C compiler in either 64 or 32 bit mode, 84/// with all warnings turned on. This is true of both the runtime code and the generated code and has been summarily tested 85/// with Visual Studio .Net (2003, 2005 and 2008) and later versions of gcc on Redhat Linux, as well as on AIX 5.2/5.3, Solaris 9/10, 86/// HPUX 11.xx, OSX (PowerPC and Intel) and Cygwin. 87/// 88/// \b Notes 89/// - The C runtime is constructed such that the library can be integrated as an archive library, or a shared library/DLL. 90/// - The C language target code generation templates are distributed with the source code for the ANTLR tool itself. 91/// 92/// \section performance Performance 93/// 94/// It is C :-). Basic testing of performance against the Java runtime, 95/// using the JDK1.6 java source code, and the Java parser provided in the examples (which is a tough test as it includes 96/// backtracking and memoization) show that the C runtime uses about half the memory and is between 2 and 3 times the speed. 97/// Tests of non-backtracking, non-memoizing parsers, indicate results significantly better than this. 98/// 99/// \section examples Downloading Examples 100/// 101/// The <a href="http://www.antlr.org/download.html">downloads page</a> of the ANTLR web site contains a downloadable 102/// zip/tar of examples projects for use with the C runtime model. It contains .sln files and source code for a 103/// number of example grammars and helps to see how to invoke and call the generated recognizers. 104///