MD-BASIC++

A pre-processor for MD-BASIC.

Roadmap:

Mini Assembler

Generates appropriate DATA or & POKE (AmperWorks) statements. It can also generate a binary payload appended to the end of the file (.inline). In inline mode, .org is not allowed (or necessary); the org will be calculated based on the file size.

Example

input:

function1:
    for i = F_START to F_END
        read x
        poke i,x
    next i
    call $300
    return
#asm
        .org $300
        .export f_start, f_end
f_start
        lda #0
        rts
f_end   .equ *-1
#endasm

function2:
#asm
        .org $300
        .poke

        lda #0
        rts

#endasm
    call $300
    return

output (before MD-BASIC):

' generated by mdbasic++ 0.0.3
#define __MDBASICXX__
#define __DATE__ "Aug 11 2017"
#define __TIME__ "23:38:14"
#define F_START 768
#define F_END 770

function1:
    for i = F_START to F_END
        read x
        poke i,x
    next i
    call $300
    return
    DATA 169,0,96

function2:
    & POKE 768,169,0,96
    call $300
    return

output (after MD-BASIC):

1  FOR A = 768 TO 770: READ B: POKE A,B: NEXT A: CALL 768: RETURN : DATA 169,0,96
2  &  POKE 768,169,0,96: CALL 768: RETURN 

Directives

        .machine    [6502 | 65c02 | 65816]      ; specify machine (default 6502)
        .org        expr                        ; set origin
        .long       [mx]                        ; '816 - assume long m or x
        .short      [mx]                        ; '816 - assume short m or x
        .data                                   ; use DATA (default)
        .poke                                   ; use & POKE
        .inline                                 ; generate a binary blob at the end of file
label   .equ        expr
        .export     label [, label ...]         ; export label (as #define)
label   .export                                 ; define and export label

Data Directives

        .db         expr [, expr ...]           ; 8-bit data
        .dw         expr [, expr ...]           ; 16-bit data
        .da         expr [, expr ...]           ; 24-bit data
        .dl         expr [, expr ...]           ; 32-bit data

        .dci        string [, string ...]       ; dextral character inverted string
        .str        string [, string ...]       ; string
        .pstr       string [, string ...]       ; pascal string

n.b.: .str, .pstr, and .dci accept a list of strings ("like this",'or this') or expressions (which will generate bytes). For .pstr, the length prefix is the length of all strings and expressions. For .dci, only the last byte of the last string (or expression) is inverted.

Address Modes

<, |, and > are address mode selectors, not unary operators. If no address mode is explicitly specified, the Mini Assembler will default to absolute address mode. If the operand size can be determined (i.e., an integer constant or symbol value is known), it will default to zp, absolute, or absolute long based on the operand size.

Expressions

Terminals

        {basic-expression}                      ; inserted as-is. only valid with .poke
        symbol                                  ; symbol
        %10                                     ; binary integer
        10                                      ; decimal integer
        $10                                     ; hexadecimal integer
        0x10                                    ; hexadecimal integer
        '10'                                    ; low-ascii string (or character constant)
        "10"                                    ; high-ascii string (or character constant)

Unary Operators

        + - ^ ~

n.b.: Unary ^ is right shift 16.

Binary Operators

        + - * / % & | ^ >> <<

n.b.: Binary operations use same precedence as C. Parenthesis are not supported within expressions.

More command-line flags

-D macroname[=value]             Define a macro
-E                               Pre-processor only
-S                               Decompile generated code
-I directory                     Specify include path (not yet ....)
-o outfile                       Specify outfile
-O level                         Specify optimization level (0,1,2)
-v, --verbose                    Be verbose
-V, --version                    Display version
    --[no-]declare               Require declarations
    --[no-]progress              Print progress
    --[no-]summary               Print summary
    --[no-]xref                  Print Cross References
-h, --help                       Display help information