104 lines
6.7 KiB
Plaintext
104 lines
6.7 KiB
Plaintext
// Main page documentation for ANTLR3C runtime. Contains
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// doxygen things only.
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//
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/// \mainpage ANTLR3 C Runtime API and Usage Guide.
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///
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/// \section version Version 3.3.1
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///
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/// This documentation is specifically for the C rutime version 3.1.x.x, which is
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/// specifically for use with version 3.1.x.x of the ANTLR recognizer generation
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/// tool. While some of the documentation may well apply to prior or future versions
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/// you should consult the manuals for the correct version whenever possible.
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///
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/// \section chchchchangeesss Changes from 3.2 to 3.3.1
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///
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/// Some changes in 3.3.1 may require small changes in your invoking programs or
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/// in the grammar itself. Please read about them here before emailing the user group,
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/// where you will be told to come and read about them here, unless they were missed
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/// from this list.
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///
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/// - \subpage changes331 Check here for API changes
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///
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/// \section intro Introduction
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///
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/// The ANTLR3 recognizer generation tool is written in Java, but allows the generation
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/// of code targeted for a number of other languages. Each target language provides a code
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/// generation template for the tool and a runtime library for use by generated recognizers.
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/// The C runtime tracks the Java runtime releases and in general when a new version of the
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/// tool is released, a new version of the C runtime will be released at the same time.
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///
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/// The documentation here is in three parts:
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///
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/// - \subpage build Building the runtime itself from source code;
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/// - \subpage generate How to tell ANTLR to generate code for the C target;
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/// - \subpage buildrec How to build the generated code
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/// - \subpage using Using the runtime and the libraries and so on;
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/// - \subpage runtime The documentation of the runtime code and functions;
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///
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/// \section background Background Information
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///
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/// The ANTLR 3 C runtime and code generation templates were written by <a href="http://www.linkedin.com/in/jimidle"> Jim Idle</a>
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/// (jimi|at|temporal-wave|dott/com) of <a href="http://www.temporal-wave.com">Temporal Wave LLC</a>.
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///
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/// The C runtime and therefore the code generated to utilize the runtime reflects the object model of the
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/// Java version of the runtime as closely as a language without class structures and inheritance can.
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/// Compromises have only been made where performance would be adversely affected such as minimizing the
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/// number of pointer to pointer to pointer to function type structures that could ensue through trying to
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/// model inheritance too exactly. Other differences include the use of token and string factories to minimize
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/// the number of calls to system functions such as calloc().This model was adopted so that overriding any
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/// default implementation of a function is relatively simple for the grammar programmer.
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///
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/// The generated code is free threading (subject to the systems calls used on any particular platform
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/// being likewise free threading.)
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///
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/// \subsection model Runtime Model
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///
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/// As there is no such thing as an object reference in C, the runtime defines a number of typedef structs that reflect
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/// the calling interface chosen by Terence Parr for the Java version of the same. The initialization of a parser,
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/// lexer, input stream or other internal structure therefore consists of allocating the memory required for
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/// an instance of the typedef struct that represents the interface, initializing any counters, and buffers etc,
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/// then populating a number of pointers to functions that implement the equivalent of the methods in the Java class.
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///
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/// The use and initialization of the C versions of a parser is therefore similar to the examples given for Java,
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/// but with a bent towards C of course. You may need to be aware of memory allocation and freeing operations
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/// in certain environments such as Windows, where you cannot allocate memory in one DLL and free it in another.
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///
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/// The runtime provides a number of structures and interfaces that the author has found useful when writing action and
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/// processing code within java parsers, and furthermore were required by the C runtime code if it was not to
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/// depart too far from the logical layout of the Java model. These include the C equivalents of String, List,
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/// Hashtable, Vector and Trie, implemented by pointers to structures. These are freely available for your own programming needs.
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///
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/// A goal of the generated code was to minimize the tracking, allocation and freeing of memory for reasons of both
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/// performance and reliability. In essence any memory used by a lexer, parser or tree parser is automatically tracked and
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/// freed when the instance of it is released. There are therefore factory functions for tokens and so on such that they
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/// can be allocated in blocks and parceled out as they are required. They are all then freed in one go, minimizing the
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/// 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
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/// the lexer, parser or tree parser, then you must make a copy of it before freeing those structures, and track it yourself
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/// after that. In practice, it is easy enough just not to release the antlr generated components until you are
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/// finished with their results.
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///
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/// \section targets Target Platforms
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///
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/// The C project is constructed such that it will compile on any reasonable ANSI C compiler in either 64 or 32 bit mode,
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/// with all warnings turned on. This is true of both the runtime code and the generated code and has been summarily tested
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/// 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,
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/// HPUX 11.xx, OSX (PowerPC and Intel) and Cygwin.
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///
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/// \b Notes
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/// - The C runtime is constructed such that the library can be integrated as an archive library, or a shared library/DLL.
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/// - The C language target code generation templates are distributed with the source code for the ANTLR tool itself.
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///
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/// \section performance Performance
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///
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/// It is C :-). Basic testing of performance against the Java runtime,
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/// using the JDK1.6 java source code, and the Java parser provided in the examples (which is a tough test as it includes
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/// backtracking and memoization) show that the C runtime uses about half the memory and is between 2 and 3 times the speed.
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/// Tests of non-backtracking, non-memoizing parsers, indicate results significantly better than this.
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///
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/// \section examples Downloading Examples
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///
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/// The <a href="http://www.antlr.org/download.html">downloads page</a> of the ANTLR web site contains a downloadable
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/// zip/tar of examples projects for use with the C runtime model. It contains .sln files and source code for a
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/// number of example grammars and helps to see how to invoke and call the generated recognizers.
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/// |