Awesome

LLVM Frontend for Tiny-C

Description

This is a re-implementation of LLVM frontend(clang) for learning.

Compilation

Required dependencies: LLVM-13, lit + FileCheck (for CodeGen tests)

$ git clone https://github.com/drop-stones/Tiny-C
$ cd Tiny-C
$ mkdir build
$ mkdir build
$ cd build
$ cmake -G Ninja .
$ ninja

Usage

Compile C Code into LLVM-IR

$ build/tools/tiny-c foo.c

Testing

Run Lexer and Parser tests. Please see unitttest directory for details.

$ ninja test

Run CodeGen tests. (To run this tests, you need to install lit and FileCheck.)
Please see test directory for details.

$ ninja check

Supported Feature

• Binary Expressions
  • + - * / == !=
• if-, while-, return- statements
• Local variables
  • Declaration: int x;
  • Assignment statement: x = 100;
• int type
• Function
  • Declaration: int add(int a, int b) {...}
  • Function Call: x = add(100, 200);

Grammar

translationUnit : (functionDefinition)*;
functionDefinition : type ident "(" (formalParameterList)? ")" block;
formalParameterList : formalParameter ( "," formalParameter )*;
formalParameter : type ident;

type : "int";
block : "{" ( statement ";" )* "}";
statement : declStmt | assignStmt | returnStmt | ifStmt | whileStmt;
declaration : type ident;
assignStmt : ident ( "=" expr )?;
returnStmt : "return" ( expr )?;
ifStmt : "if" "(" expr ")" block ( "else" block )?;
whileStmt : "while" "(" expr ")" block;

expr : relationalExpr (( "==" | "!=" ) relationExpr )*;
relationalExpr : additiveExpr (( "<" | "<=" | ">" | ">=" ) additiveExpr)*;
additiveExpr : term (( "+" | "-" ) term)*;
term : factor (( "*" | "/" ) factor)*;
factor : number | ident ( "(" ( expr ( "," expr )* )? ")" )? | "(" expr ")";
ident : ([a-zA-Z])+;
number : ([0-9])+;

Unsupported Feature

• Scope Analysis
• Semantic Analysis
• Types other than int
• Pointer Type
• Array Type