NaiveCompiler

A hobby C compiler created in Python and LLVM

blogs about steps reading gcc and clang and then build your own compiler https://mithrilwoodrat.github.io/categories/#compiler

Docker

Build

cd Docker
docker build -t naivescript .

Run

docker run -i -t naivescript:latest /opt/naivecompiler/test.sh

Building

This project needs llvm-6.0 and cmake to build

Building for ubuntu

# install deps
apt-get install -y llvm-6.0 llvm-c-6.0 cmake libncurses5-dev libz-dev
# run build script
./build.sh

Usage

using python2 compiler.py <input> to display AST

using python2 compiler.py <input> -o <output> to generate object file

using ld -e <symbol> to link obj file to ELF, set <symbol> as entry point(must return void).

if link with glibc crt, then you can writing as normal c program.

you can using link.sh <input>.o <output> to do this.

DEMO

TODO

• support extern function decl
• formatted AST show function
• Implement Expr Class for Gen different Code in CodeGen

• support StringLiteral in backend
  • NodeFactory CreateValueNode return different Node Class
• support array and pointer in backend

• [] support void type in funcdecl
• [] support empty return stmt
• support '||' '&&' binaryOp (frontend and backend)
• refact condition generate
• Read Clang CFG.cpp and refact ASTRewrite Class

Repository contents

FrontEnd

• compiler.py Main interface of NaiveCompiler
• c_parser.py Contains the lex and parser implements with ply
• c_ast.py Contains the AST defination of NaiveCompiler
• codegen.py Generate middle code (CFG, basicblocks) from AST
• serialize_handler.py Convert middle code to struct then passing to backend

Backend

• ast\* Defining the AST in C++
• serialize\* Parsing the struct generate by python,then convert it to AST
• codegen\* Real Code Generate using LLVM API

使用方法

使用 python2 compiler.py <input> 显示 AST

使用 python2 compiler.py <input> -o <output> 生成 obj

使用 ld -e <symbol> 将 obj 文件 链接为 ELF， 并指定 为 entry point。（由于未给 naivecompiler 实现 crt， entry point 的函数不能返回参数，只能设置为 void)

可以使用 ld 链接上 ld，然后就可以调用 glibc 的函数了。crt 问题可以链接上 glic 的 crt

ld -o test -dynamic-linker /lib64/ld-linux-x86-64.so.2 /usr/lib/x86_64-linux-gnu/crt1.o /usr/lib/x86_64-linux-gnu/crti.o -lc test.o /usr/lib/x86_64-linux-gnu/crtn.o

调用 link.sh test.o test