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R E A D M E

by: Sean Fredericksen

Francisco Mota

Josh McMulin

date: Dec 9 2010

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How to use the compiler

To use the compiler, you must run main.py from the command line. main.py reads in source code from standard input, and outputs the compiled code to standard output, with any compilation errors to standard error.

For example, on a UNIX system with Python, the following command will read code from the file "source-code.kln", compile it to "target.tm", and if there are any errors it will print them to the screen (standard error).

python main.py < source-code.kln > target.tm

How the code is organized

tokens.py defines the token class, which represents individual tokens, as well as the various types of tokens.

scanner.py converts code into a stream of tokens.

parser.py is a table-driven parser. It builds the parse table from a description of the grammar and then it uses the typical LL1 table-driven parsing algorithm to determine the syntactic validity of the program.

kleinTypes.py is a semantic analyser. It traverses the AST and checks whether each type is the correct type and prints out a symbol table.

symboltable.py defines the symbol table and the entries that go in the symbol table.

main.py is the program that reads code from standard input and tells the parser to parse it.

emit.py handles the emission of actual target code, keeping track of the current instruction address.

codegen.py converts the AST into intermediate code, and using emit.py, converts the intermediate code into target code.

Optional features

'#include' allows you to include the code of another file in your file. For example, when reading a file with the line

#include "foo.kln"

The compiler will look for the file "foo.kln" in the current directory (the one from which the compiler was invoked), and include its code inside the current file.

To enable '#include', pass the '-i' or '--include' flags to the compiler. To compile code in the 'include_examples' folder, you would need to be in that folder, and then do

$ python ../main.py --include < foo.kln

to compile code with '#include' (or you can use the '-i' flag).

Miscellaneous

There are sample klein programs in the examples folder, sample klein programs that use '#include' in the include_examples folder, and for testing purposes there are programs with syntactic errors in the syntax_errors folder, and semantic errors in semantic_errors folder.