mC Compiler

This repository holds a code-base for the compiler construction course.

A more detailed overview can be found in doc/overview.md.

Input Language

• see mC Specification
• see examples

Prerequisites

• Meson in a recent version (0.44.0) (you may want to install it via pip3 install --user meson)
• Ninja
• time, typically located at /usr/bin/time, do not confuse with the Bash built-in
• flex for generating the lexer
• bison for generating the parser
• a compiler supporting C11 (and C++14 for unit tests) -- typically GCC or Clang
• pdftk for the generation of CFG - pdfs (see CFG paragraph below)

Building and Testing

Generate the build directory. Google Test is used for unit testing. Meson downloads and builds it automatically if it is not found on your system.

$ meson builddir
$ cd builddir

Meson creates Ninja build files by default. Let's build.

$ ninja

Unit tests can be run directly with Ninja (or Meson).

$ ninja test

For integration testing we pass all example inputs to the compiler and observe its exit code. This is automated by a Bash script.

$ ../test/integration

For testing the assembler code we originally were using a self written testing framework in the mC language (/doc/test_mCc/test1.mC, see /doc/test_mCc/usage.txt for info on how to run test). We then further on added a few google tests, which only compare outputs for some simple code snippets.

For more information how to use the compiler, please try $ ./mcC --help

To generate a CFG for a mC program please use mC_to_cfg like in the following: ./mC_to_cfg %yourfile% > cfg.txt && dot -Tpdf cfg.txt | csplit --quiet --elide-empty-files --prefix=tmpx - "/%%EOF/+1" "{}" && pdftk tmpx cat output cfg.pdf && rm -f tmpx*g

This generates a pdf called 'cfg.pdf' with one cfg per function/page. Make sure to replace %yourfile% with a valid mC program, eg. ../doc/examples/fib.mC We had some problems using dot to generated multiple graphs in one picture, this method attaches all pictures into a single pdf. You might need to install pdftk for this to work.

Known Issues

• The compiler optimization are not implemented

• Type checking is incomplete for arrays. You can for instance add an array and a primitive as long both have the same type.

void main(){int[3] a; int b; b = a;} 

will lead to an error message and the assignment of a primitive to an array. An reassignment of an array will also result in an error message.