; ---------------- ; K2 BASIC ; ---------------- ; this file should be included twice: ; 1st time will define the macros and put some code in area ROM ; 2nd time will resolve missing helper functions #if !defined(RESOLVE) RESOLVE = 0 DEFINE = 1 #else RESOLVE = 1 DEFINE = 0 #endif ; helpers are stored in: ; .area ROM: code & const data (romable) ; .area RAM: code & data (self-modifying) ; .area ROP: ROP coded functions. the SP will point into this area. ; must be in RAM and words overwritten by interrupts must be restored. ; .area DATA: zero-initialized data ; ---------------------------------- ; return from ROP coded function ; ; the ROP engine has no stack, therefore return addresses ; are stored in dedicated variables, one for each function level: ; level0 calls no other functions, level1 only level0 functions and so on. ; NOTE: these functions are NOT reentrant! #if DEFINE .macro PROC_START ld (return + 1 + level*4),sp ld sp,$+4 ret .endm .macro RETURN .dw return + level*4 .endm .area RAM return:: ld sp,0 \ ret ; level0 -- address set at function entry ld sp,0 \ ret ; level1 ld sp,0 \ ret ; level2 ld sp,0 \ ret ; ... ld sp,0 \ ret ld sp,0 \ ret ld sp,0 \ ret ld sp,0 \ ret ld sp,0 \ ret ld sp,0 \ ret ; level9 #endif ; ---------------------------------- ; local variables and rop coded getter and setter ; to be placed in a library #if RESOLVE .macro DEFINE_LVAR &NAME ; setters and getters for local int16 variable '&NAME': .area ROM .if required(ld_&NAME_hl) ld_&NAME_hl:: ld (&NAME),hl \ ret .endif .if required(ld_&NAME_de) ld_&NAME_de:: ld (&NAME),de \ ret .endif .if required(ld_&NAME_bc) ld_&NAME_bc:: ld (&NAME),bc \ ret .endif .if required(ld_&NAME_ix) ld_&NAME_ix:: ld (&NAME),ix \ ret .endif .if required(ld_&NAME_iy) ld_&NAME_iy:: ld (&NAME),iy \ ret .endif .if required(ld_hl_&NAME) ld_hl_&NAME:: ld hl,(&NAME) \ ret .endif .if required(ld_bc_&NAME) ld_bc_&NAME:: ld bc,(&NAME) \ ret .endif .if required(ld_ix_&NAME) ld_ix_&NAME:: ld ix,(&NAME) \ ret .endif .if required(ld_iy_&NAME) ld_iy_&NAME:: ld iy,(&NAME) \ ret .endif .area RAM .if required(ld_de_&NAME) || required(&NAME) &NAME:: equ $+1 ld_de_&NAME:: ld de,0 \ ret ; <-- value set with setter .endif .endm DEFINE_LVAR int00 ;level0, int variable #1 DEFINE_LVAR int01 DEFINE_LVAR int02 DEFINE_LVAR int03 DEFINE_LVAR int04 DEFINE_LVAR int05 DEFINE_LVAR int06 DEFINE_LVAR int07 DEFINE_LVAR int10 DEFINE_LVAR int11 DEFINE_LVAR int12 DEFINE_LVAR int13 DEFINE_LVAR int14 DEFINE_LVAR int15 DEFINE_LVAR int16 DEFINE_LVAR int17 DEFINE_LVAR int20 DEFINE_LVAR int21 DEFINE_LVAR int22 DEFINE_LVAR int23 DEFINE_LVAR int24 DEFINE_LVAR int25 DEFINE_LVAR int26 DEFINE_LVAR int27 DEFINE_LVAR int30 DEFINE_LVAR int31 DEFINE_LVAR int32 DEFINE_LVAR int33 DEFINE_LVAR int34 DEFINE_LVAR int35 DEFINE_LVAR int36 DEFINE_LVAR int37 DEFINE_LVAR int40 DEFINE_LVAR int41 DEFINE_LVAR int42 DEFINE_LVAR int43 DEFINE_LVAR int44 DEFINE_LVAR int45 DEFINE_LVAR int46 DEFINE_LVAR int47 DEFINE_LVAR int50 DEFINE_LVAR int51 DEFINE_LVAR int52 DEFINE_LVAR int53 DEFINE_LVAR int54 DEFINE_LVAR int55 DEFINE_LVAR int56 DEFINE_LVAR int57 DEFINE_LVAR int60 DEFINE_LVAR int61 DEFINE_LVAR int62 DEFINE_LVAR int63 DEFINE_LVAR int64 DEFINE_LVAR int65 DEFINE_LVAR int66 DEFINE_LVAR int67 DEFINE_LVAR int70 DEFINE_LVAR int71 DEFINE_LVAR int72 DEFINE_LVAR int73 DEFINE_LVAR int74 DEFINE_LVAR int75 DEFINE_LVAR int76 DEFINE_LVAR int77 DEFINE_LVAR int80 DEFINE_LVAR int81 DEFINE_LVAR int82 DEFINE_LVAR int83 DEFINE_LVAR int84 DEFINE_LVAR int85 DEFINE_LVAR int86 DEFINE_LVAR int87 DEFINE_LVAR int90 DEFINE_LVAR int91 DEFINE_LVAR int92 DEFINE_LVAR int93 DEFINE_LVAR int94 DEFINE_LVAR int95 DEFINE_LVAR int96 DEFINE_LVAR int97 #endif ; define a local int16 variable with setters and getters: ; this is done by assigning the variable to an entry in the above DEFINE_LVARs ; type = int16 (default) ; 'level' must be defined ; 'num_lvars' must be defined and will be incremented ; macro LOCAL must be placed at the end of a function ; and it will only pull in those getters and setters which were actually used #if DEFINE .macro LOCAL &NAME ; local variable '&NAME': num_lvars = num_lvars+1 _&NAME = int{level}{num_lvars} .if required(ld_hl_&NAME) ld_hl_&NAME = ld_hl_int{level}{num_lvars} .endif .if required(ld_de_&NAME) ld_de_&NAME = ld_de_int{level}{num_lvars} .endif .if required(ld_bc_&NAME) ld_bc_&NAME = ld_bc_int{level}{num_lvars} .endif .if required(ld_ix_&NAME) ld_ix_&NAME = ld_ix_int{level}{num_lvars} .endif .if required(ld_iy_&NAME) ld_iy_&NAME = ld_iy_int{level}{num_lvars} .endif .if required(ld_&NAME_hl) ld_&NAME_hl = ld_int{level}{num_lvars}_hl .endif .if required(ld_&NAME_de) ld_&NAME_de = ld_int{level}{num_lvars}_de .endif .if required(ld_&NAME_bc) ld_&NAME_bc = ld_int{level}{num_lvars}_bc .endif .if required(ld_&NAME_ix) ld_&NAME_ix = ld_int{level}{num_lvars}_ix .endif .if required(ld_&NAME_iy) ld_&NAME_iy = ld_int{level}{num_lvars}_iy .endif .endm #endif ; ========================================== ; EXAMPLE ; ========================================== #if 0 ; ------------------------------------------- ; int max ( int a, int b ) = a >= b ? a : b ; ------------------------------------------- #local level = 0 num_lvars = 0 max:: PROC_START .dw ld_a_de ; store de -> a .dw ld_b_hl ; store hl -> b ; .dw ld_de_a ; .dw ld_hl_b .dw ge_cy ; built-in, no local variables in memory .dw jp_cy, L1 .dw ld_hl_a RETURN L1: .dw ld_hl_b RETURN LOCAL a LOCAL b #endlocal ; ------------------------------------------- ; int min ( int a, int b ) = a >= b ? b : a ; ------------------------------------------- #local level = 0 num_lvars = 0 min:: PROC_START .dw ld_a_de ; store de -> a .dw ld_b_hl ; store hl -> b ; .dw ld_de_a ; .dw ld_hl_b .dw jp_lt .dw ld_hl_b, L1 RETURN L1: .dw ld_hl_a RETURN LOCAL a LOCAL b #endlocal ; ------------------------------------------- ; int minmax ( int a, int n, int e ) = max(a,min(n,e)) ; ------------------------------------------- #local level = 1 ; assuming that min and max are level0 functions num_lvars = 0 minmax:: PROC_START .dw ld_a_bc ; todo: caller? ; .dw ld_n_de ; .dw ld_e_hl ; store hl -> e ; .dw ld_de_n ; .dw ld_hl_e .dw min ; level0 function .dw ld_de_a .dw max ; level0 function RETURN LOCAL a LOCAL n LOCAL e #endlocal #endif ; ----- Example -----