(* Partical grammar for msp430-asm *)

Line = Label | Directive | Insn ;

Insn = NoEm | OneEm | Special | OneArg | TwoArg | Jump ;

(* Instruction formats *)
NoEm    = OpNoEm ;
OneEm   = OpOneEm Dst ;
Special = "reti" | "br" Src ;
OneArg  = OpOneArg Src ;
TwoArg  = OpTwoArg Src ','? Dst ;
Jump    = OpJump Expr ;


(* Addressing modes *)
Src = '#' (SrcSpecial | '-'? Expr)
    | Absolute
    | PostInc
    | Indexed
    | Direct ;

Dst = '#' (SrcSpecial | Expr)
    | Absolute
    | Indirect
    | Indexed
    | Direct ;

Direct     = Reg ;
Indirect   = '@' Reg ;
PostInc    = Indirect '+'? ;
Indexed    = Number '(' Reg ')' ;
Immediate  = '#' Expr ;
Absolute   = '&' Expr ;
SrcSpecial = 0 | 1 | '-' 1 | 0xffff | 2 | 4 | 8 ;
DstSpecial = 0 | 1 ;

Expr       = '-'? Number ;

(* Pseudo-terminals *)
Reg = "pc"  | "sp"  | "sr"  | "cg" 
    | "r0"  | "r1"  | "r2"  | "r3" 
    | "r4"  | "r5"  | "r6"  | "r7" 
    | "r8"  | "r9"  | "r10" | "r11"
    | "r12" | "r13" | "r14" | "r15" ;
Identifier = ID_START ID_CONTINUE* ;
Number = '-'? DIGIT ;