ARM C Compiler (ACC)

ACC is a project that its only aim is to improve my knowledge of two topics, C language and ARM assembly. I think this is a good exercise to go deep into both topics.

Parser

The ACC is a LALR(1) parser, that means it is a Look-Ahead Left-to-Right parser.

Grammar

S -> int main "(" ")" "{" E "}"
E -> return I;
     | if "(" B ")" "{" E "}"
     | if "(" B ")" "{" E "}" else "{" E "}"
I -> [0-9]+
B -> I < I
     | I <= I
     | I == I
     | I >= I
     | I > I
     | ! B
     | "(" B ")"

Example

C code:

int main()
{
    if (1 < 2)
    {
	    if (4 > 10)
	    {
		    return 1;
	    }
	    else {
		    return 2;
	    }
    }
    return 0;
}

Assembly generated:

	.text
	.global main
main:
	mov r0, #1
	mov r1, #2
	cmp r0, r1
	bge if_else_0
	mov r0, #4
	mov r1, #10
	cmp r0, r1
	ble if_else_1
	mov r0, #1
	bx lr
if_else_1:
	mov r0, #2
	bx lr
if_else_0:
	mov r0, #0
	bx lr