MicroC compiler

Compiler for MicroC, a small subset of C language. Course page : https://github.com/lillo/compiler-course-unipi/

Requirement to build the code

The code requires:

• OCaml >= 4.10.1
• Menhir >= 20200624
• ppx_deriving >= 4.5
• llvm >= 10.0.0

You can install the required dependencies via opam

$ opam install menhir ppx_deriving llvm

To use the compile you also need to install Clang.

Building the code and using the compiler

Typing make will generate a microcc.native executable:

$ make

To clean-up the folder, run:

$ make clean

To Parse and print the AST of a source file input.mc, run:

$ ./microcc -p input.mc

To perform semantic checks and print the TAST of a source file input.mc, run:

$ ./microcc -s input.mc

To print the generated code of a source file input.mc, run:

$ ./microcc -d input.mc

To place the output into file output.txt, run:

$ ./microcc -d input.mc -o output.txt

To optimize the generated code, rum:

$ ./microcc -O input.mc

To compile, run:

$ ./microcc input.mc

Once you have obtained your bitcode file a.bc, you have to link it with the object code of the runtime support.

$ make rtsupport
$ llvm-link a.bc rt-support.bc -o test.bc
$ llc -filetype=obj test.bc
$ clang test.o

Otherwise, to obtain directly an execuable, run:

$ make rtsupport
$ make compile file=input.mc

Testing of implementation

The directory testsemant contains some tests used to test semantic analysis.

$ make testsemant

The directory testcodegen contains some tests used to test semantic analysis. Each test case consists of a small MicroC program (the file with extension *.mc) together with the result that the program is supposed to produce (the file with extension *.out). The following command execute all of them and check differences with expected output.

$ make testcodegen

Directory structure

Here is a description of content of the repository

src/                               <-- The source code lives here
Makefile                           <-- Driver for `make` (uses OCB)
_tags                              <-- OCamlBuild configuration
test/                              <-- Some programs used to test compiler
testsemnat/                        <-- Some programs to test semantic anlaysis
testcodegen/                       <-- Some programs to test code generation

The source code

The src/ directory provides:

ast.ml                       <-- Definition of the abstract syntax tree of MicroC
tast.ml                      <-- Definition of the typed abstract syntax tree of MicroC 
microcc.ml                   <-- The file from which build the executable 
parser_engine.ml             <-- Module to interact with the parser
codegen.ml                   <-- Module that implements the code generation
util.ml                      <-- Utility module  
opt_pass.ml                  <-- Module that implements some simple optimizations
rt-support.c                 <-- The runtime support to be linked to bitcode files produced by your compiler
parser.mly                   <-- Menhir specification of the grammar 
scanner.mll                  <-- ocamllex specification of the scanner
semant.ml                    <-- Module that implements the semantic checker
symbol_table.mli             <-- Interface of a polymorphic symbol table data type
symbol_table.ml              <-- Implementation of a polymorphic symbol table data type