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diff --git a/docs/tutorial/LangImpl8.html b/docs/tutorial/LangImpl8.html new file mode 100644 index 0000000000..96b776211d --- /dev/null +++ b/docs/tutorial/LangImpl8.html @@ -0,0 +1,143 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" + "http://www.w3.org/TR/html4/strict.dtd"> + +<html> +<head> + <title>Kaleidoscope: Conclusion, ideas for extensions, and other useful tidbits</title> + <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> + <meta name="author" content="Chris Lattner"> + <link rel="stylesheet" href="../llvm.css" type="text/css"> +</head> + +<body> + +<div class="doc_title">Kaleidoscope: Conclusion</div> + +<div class="doc_author"> + <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a></p> +</div> + +<!-- *********************************************************************** --> +<div class="doc_section"><a name="intro">Tutorial Conclusion</a></div> +<!-- *********************************************************************** --> + +<div class="doc_text"> + +<p>Welcome to the the final chapter of the "<a href="index.html">Implementing a +language with LLVM</a>" tutorial. In the course of this tutorial, we have grown +our little Kaleidoscope language from being a useless toy, to being a +semi-interesting (but probably still useless) toy. :)</p> + +<p>It is interesting to see how far we've come, and how little code it has +taken. We built the entire lexer, parser, AST, code generator, and an +interactive run-loop (with a JIT!) by-hand in under 700 lines of +(non-comment/non-blank) code.</p> + +<p>Our little language supports a couple of interesting features: it supports +user defined binary and unary operators, it uses JIT compilation for immediate +evaluation, and it supports a few control flow constructs with SSA construction. +</p> + +<p>Part of the idea of this tutorial was to show you how easy and fun it can be +to define, build, and play with languages. Building a compiler need not be a +scary or mystical process! Now that you've seen some of the basics, I strongly +encourage you to take the code and hack on it. For example, try adding:</p> + +<ul> +<li><b>global variables</b> - While global variables have questional value in +modern software engineering, they are often useful when putting together quick +little hacks like the Kaleidoscope compiler itself. Fortunately, our current +setup makes it very easy to add global variables: just have value lookup check +to see if an unresolved variable is in the global variable symbol table before +rejecting it. To create a new global variable, make an instance of the LLVM +<tt>GlobalVariable</tt> class.</li> + +<li><b>typed variables</b> - Kaleidoscope currently only supports variables of +type double. This gives the language a very nice elegance, because only +supporting one type means that you never have to specify types. Different +languages have different ways of handling this. The easiest way is to require +the user to specify types for every variable definition, and record the type +of the variable in the symbol table along with its Value*.</li> + +<li><b>arrays, structs, vectors, etc</b> - Once you add types, you can start +extending the type system in all sorts of interesting ways. Simple arrays are +very easy and are quite useful for many different applications. Adding them is +mostly an exercise in learning how the LLVM <a +href="../LangRef.html#i_getelementptr">getelementptr</a> instruction works. +The getelementptr instruction is so nifty/unconventional, it <a +href="../GetElementPtr.html">has its own FAQ</a>!).</li> + +<li><b>standard runtime</b> - Our current language allows the user to access +arbitrary external functions, and we use it for things like "printd" and +"putchard". As you extend the language to add higher-level constructs, often +these constructs make the most amount of sense to be lowered into calls into a +language-supplied runtime. For example, if you add hash tables to the language, +it would probably make sense to add the routines to a runtime, instead of +inlining them all the way.</li> + +<li><b>memory management</b> - Currently we can only access the stack in +Kaleidoscope. It would also be useful to be able to allocate heap memory, +either with calls to the standard libc malloc/free interface or with a garbage +collector. If you choose to use garbage collection, note that LLVM fully +supports <a href="../GarbageCollection.html">Accurate Garbage Collection</a> +including algorithms that move objects and need to scan/update the stack.</li> + +<li><b>debugger support</b> - LLVM supports generation of <a +href="../SourceLevelDebugging.html">DWARF Debug info</a> which is understood by +common debuggers like GDB. Adding support for debug info is fairly +straight-forward. The best way to understand it is to compile some C/C++ code +with "<tt>llvm-gcc -g -O0</tt>" and taking a look at what it produces.</li> + +<li><b>exception handlingsupport</b> - LLVM supports generation of <a +href="../ExceptionHandling.html">zero cost exceptions</a> which interoperate +with code compiled in other languages. You could also generate code by +implicitly making every function return an error value and checking it. You +could also make explicit use of setjmp/longjmp. There are many different ways +to go here.</li> + +<li><b>object orientation, generics, database access, complex numbers, +geometric programming, ...</b> - Really, there is +no end of crazy features that you can add to the language.</li> + +</ul> + +<p> +Have fun - try doing something crazy and unusual. Building a language like +everyone else always has is much less fun than trying something a little crazy +and off the wall and seeing how it turns out. If you get stuck or want to talk +about it, feel free to email the <a +href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">llvmdev mailing +list</a>: it has lots of people who are interested in languages and are often +willing to help out. +</p> + +<p>Before we end, I want to talk about some "tips and tricks" for generating +LLVM IR. These are some of the more subtle things that may not be obvious, but +are very useful if you want to take advantage of LLVM's capabilities.</p> + +</div> + +<!-- *********************************************************************** --> +<div class="doc_section"><a name="tipsandtricks">Tips and Tricks</a></div> +<!-- *********************************************************************** --> + +<div class="doc_text"> + +<p></p> + +</div> + +<!-- *********************************************************************** --> +<hr> +<address> + <a href="http://jigsaw.w3.org/css-validator/check/referer"><img + src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a> + <a href="http://validator.w3.org/check/referer"><img + src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a> + + <a href="mailto:sabre@nondot.org">Chris Lattner</a><br> + <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br> + Last modified: $Date: 2007-10-17 11:05:13 -0700 (Wed, 17 Oct 2007) $ +</address> +</body> +</html> diff --git a/docs/tutorial/index.html b/docs/tutorial/index.html index 12644dd7a4..52ce42bd46 100644 --- a/docs/tutorial/index.html +++ b/docs/tutorial/index.html @@ -34,7 +34,7 @@ <li><a href="LangImpl5.html">Extending the language: control flow</a></li> <li><a href="LangImpl6.html">Extending the language: user-defined operators</a></li> <li><a href="LangImpl7.html">Extending the language: mutable variables / SSA construction</a></li> - <li>Thoughts and ideas for extensions</li> + <li><a href="LangImpl8.html">Conclusion, ideas for extensions, and other useful tidbits</a></li> </ol></li> <li>Advanced Topics <ol> |