* MCS: The Ximian C# compiler
- MCS began as an experiment to learn the features of C# by
- writing a large C# program. MCS is currently able to parse C#
- programs and create an internal tree representation of the
- program. MCS can parse itself.
+ MCS is currently able to compile small C# programs (there is
+ a test suite included that you can use).
+
+ All type, field, method, delegates definitions are now emitted
+ and the body of constructors and methods is being generated
+ for a subset of the language. Although MCS can parse itself,
+ it cant not yet compile itself. Most statements are generated
+ correctly and about 80% of the C# expressions are supported.
Work is progressing quickly on various fronts in the C#
- compiler. Recently I started using the System.Reflection API
- to load system type definitions and avoid self-population of
- types in the compiler and dropped my internal Type
- representation in favor of using the CLI's System.Type.
+ compiler.
+
+ A test suite is being built currently to track the progress of
+ the compiler.
** Phases of the compiler
have to postpone this decision until the above steps
are finished.
- * Code generation: nothing done so far, but I do not
- expect this to be hard, as I will just use
- System.Reflection.Emit to generate the code.
-
+ * Code generation: The code generation is done through
+ the System.Reflection.Emit API.
+
</ul>
<a name="tasks">
Simple tasks:
<ul>
- * Array declarations are currently being ignored,
-
* PInvoke declarations are not supported.
- * Pre-processing is not supported.
-
- * Attribute declarations and passing currently ignored.
+ * Extern declarations are missing.
- * Compiler does not pass around line/col information from tokenizer for error reporting.
+ * Pre-processing is not supported.
* Jay does not work correctly with `error'
productions, making parser errors hard to point. It
would be best to port the Bison-To-Java compiler to
- become Bison-to-C# compiler (bjepson@oreilly.com
- might have more information)
+ become Bison-to-C# compiler.
+
+ Nick Drochak has started a project on SourceForge for this.
+ You can find the project at: <a href="http://sourceforge.net/projects/jb2csharp/">
+ http://sourceforge.net/projects/jb2csharp/</a>
</ul>
- Critical tasks:
+ Larger tasks:
<ul>
- * Resolve "base" classes and "base" interfaces for
- classes, structs and interfaces.
+ * Implement constant expression evaluator.
+
+ * Implement constant declarations.
+ </ul>
+
+ Interesting and Fun hacks to the compiler:
+
+ <ul>
+ * Finishing the JB port from Java to C#. If you are
+ interested in working on this, please contact the project admin on SourceForge:
+ <a href="http://sourceforge.net/projects/jb2csharp/">
+ http://sourceforge.net/projects/jb2csharp/</a>
+
+ More on JB at: <a href="http://www.cs.colorado.edu/~dennis/software/jb.html">
+ http://www.cs.colorado.edu/~dennis/software/jb.html</a>
+
+ JB will allow us to move from the Berkeley Yacc
+ based Jay to a Bison-based compiler (better error
+ reporting and recovery).
+
+ * Semantic Analysis: Return path coverage and
+ initialization before use coverage are two great
+ features of C# that help reduce the number of bugs
+ in applications. It is one interesting hack.
- Once this is done, we can actually do the semantic
- analysis, because otherwise we do not know who our
- parents are.
</ul>
** Questions and Answers
In the future I want to port one of the Bison/Java ports to C# for
the parser.
-Q: How do I compile it?
+Q: Should someone work on a GCC front-end to C#?
+
+A: I would love if someone does, and we would love to help anyone that
+ takes on that task, but we do not have the time or expertise to
+ build a C# compiler with the GCC engine. I find it a lot more fun
+ personally to work on C# on a C# compiler, which has an intrinsic
+ beauty.
+
+ We can provide help and assistance to anyone who would like to work
+ on this task.
+
+Q: Should someone make a GCC backend that will generate CIL images?
+
+A: I would love to see a backend to GCC that generates CIL images. It
+ would provide a ton of free compilers that would generate CIL
+ code. This is something that people would want to look into
+ anyways for Windows interoperation in the future.
+
+ Again, we would love to provide help and assistance to anyone
+ interested in working in such a project.
+
+Q: What about making a front-end to GCC that takes CIL images and
+ generates native code?
+
+A: I would love to see this, specially since GCC supports this same
+ feature for Java Byte Codes. You could use the metadata library
+ from Mono to read the byte codes (ie, this would be your
+ "front-end") and generate the trees that get passed to the
+ optimizer.
+
+ Ideally our implementation of the CLI will be available as a shared
+ library that could be linked with your application as its runtime
+ support.
+
+ Again, we would love to provide help and assistance to anyone
+ interested in working in such a project.
+
+Q: But would this work around the GPL in the GCC compiler and allow
+ people to work on non-free front-ends?
-A: Compiling MCS currently requires you to run my port of <a
- href="http://primates.ximian.com/~miguel/code/jay.cs.tar.gz">Jay to
- C#</a> on a Unix system to generate the parser, and then you need
- to use Microsoft's .NET csc.exe compiler to compile the compiler.
+A: People can already do this by targeting the JVM byte codes (there
+ are about 130 compilers for various languages that target the JVM).
- You only need to compile the compiler compiler (C code), the
- samples are Java samples that I did not port, and you do not need
- them.
+Q: Why are you writing a JIT engine instead of a front-end to GCC?
- It might be simple to port Jay.cs to Windows, but I have not tried
- this.
+A: The JIT engine and runtime engine will be able to execute CIL
+ executables generated on Windows.
You might also want to look at the <a href="faq.html#gcc">GCC</a>
section on the main FAQ
projects / mono.git / blobdiff