I didn't figure out how to get started on this topic alone, this is all following the great information provided by Nora Sandler on the topic of writing a C compiler, I'd highly recommend checking out her blog series and book!

How to run

For a C source code file prog.c, this can be compiled by running cargo run prog.c:

> cat prog.c
int main() {
   return 2;
}
> cargo run prog.c
> cat prog.s
    .globl main
main:
    pushq %rbp
    movq %rsp, %rbp
    subq $0, %rsp
    movl $2, %eax
    movq %rbp, %rsp
    popq %rbp
    ret

The output file stem (filename without extension) will be the same as the input file. Ie, test.c would be compiled to test.s.

Generating an executable

A small compiler driver binary crate is available that runs the gcc preprocessor, the compiler binary crate, and the gcc assembler and linker, to produce an executable.

Again, assuming a C source code file prog.c, this can be run as follows:

> cat prog.c
int main() {
   return 2;
}
> cargo run --bin compiler-driver prog.c
   Compiling c_compiler v0.0.0 (/home/dev/code)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.19s
     Running `target/debug/compiler-driver prog.c`
Preprocessed output: "prog.i"
Compiled output: "prog.s"
Executable output: "prog.out"
> ./prog.out
> echo $?
2

What is supported

Target architecture

This is only targeting x86-64.

C language features

Currently, this only supports compiling C programs that use a very limited subset of the C programing language features:

• a single (main) function
• a single return statement
• the return statement can contain nested applications of unary operators, but the innermost operand must be a numerical literal