diff options
Diffstat (limited to 'programs/lexer.s')
| -rw-r--r-- | programs/lexer.s | 231 |
1 files changed, 0 insertions, 231 deletions
diff --git a/programs/lexer.s b/programs/lexer.s deleted file mode 100644 index cd5bb54..0000000 --- a/programs/lexer.s +++ /dev/null @@ -1,231 +0,0 @@ -; Lexer, and supporting routines for SuBAsm. - -; Enums. - -; Directives. -DIR_ORG = 0 ; Origin. -DIR_BYTE = 1 ; Byte = 8 bits. -DIR_WORD = 2 ; Word = 16 bits. -DIR_DWORD = 3 ; Dword = 32 bits. -DIR_QWORD = 4 ; Qword = 64 bits. -DIR_INCL = 5 ; Include. - -; Tokens. -TOK_DIR = 0 ; Directive. -TOK_LOCAL = 1 ; Local syobol. -TOK_LABEL = 2 ; Label. -TOK_SYM = 3 ; Symbol. -TOK_EXPR = 4 ; Expression. -TOK_CSV = 5 ; Comma separated value. -TOK_STR = 6 ; String. -TOK_CHAR = 7 ; Character. -TOK_IND = 8 ; Indirect addressing. -TOK_IMM = 9 ; Immediate data. -TOK_MNE = 10 ; Opcode/Mnemonic. -TOK_RS = 11 ; Register size prefix. -TOK_COMM = 12 ; Comment. -TOK_HEX = 13 ; Hex value. -TOK_DEC = 14 ; Decimal value. -TOK_BIN = 15 ; Binary value. -TOK_INCL = 16 ; Include file. - -; Pre-Tokens. -PTOK_DOT = 0 ; . -PTOK_AT = 1 ; @ -PTOK_COLON = 2 ; : -PTOK_EQU = 3 ; = -PTOK_PLUS = 4 ; + -PTOK_MINUS = 5 ; - -PTOK_GT = 6 ; > -PTOK_LT = 7 ; < -PTOK_LBRAK = 8 ; ( -PTOK_RBRAK = 9 ; ) -PTOK_COMMA = 10 ; , -PTOK_X = 11 ; x -PTOK_Y = 12 ; y -PTOK_DQUOT = 13 ; " -PTOK_SQUOT = 14 ; ' -PTOK_HASH = 15 ; # -PTOK_SCOLN = 16 ; ; -PTOK_DOLR = 17 ; $ -PTOK_PRCNT = 18 ; % -PTOK_NUM = 19 ; 0-9 -PTOK_ALPH = 20 ; a-z A-Z -PTOK_OTHR = 21 ; Everything else. - -; Expressions. -EXPR_PLUS = 0 ; Plus. -EXPR_MINUS = 1 ; Minus. -EXPR_LOW = 2 ; Lower half of address. -EXPR_HIGH = 3 ; Upper half of address. -EXPR_NONE = 4 ; No expression. - - -; Data. -.org lexer_data -; Jump table for parsing pre-tokens. -swtab: - .word ptok_dot ; PTOK_DOT - .word ptok_at ; PTOK_AT - .word ptok_col ; PTOK_COLON - .word ptok_equ ; PTOK_EQU - .word ptok_plus ; PTOK_PLUS - .word ptok_min ; PTOK_MINUS - .word ptok_gt ; PTOK_GT - .word ptok_lt ; PTOK_LT - .word ptok_lbrk ; PTOK_LBRAK - .word ptok_rbrk ; PTOK_RBRAK - .word ptok_com ; PTOK_COMMA - .word ptok_xr ; PTOK_X - .word ptok_yr ; PTOK_Y - .word ptok_dqu ; PTOK_DQUOT - .word ptok_squ ; PTOK_SQUOT - .word ptok_hash ; PTOK_HASH - .word ptok_scol ; PTOK_SCOLN - .word ptok_dolr ; PTOK_DOLR - .word ptok_prcn ; PTOK_PRCNT - .word ptok_num ; PTOK_NUM - .word ptok_alph ; PTOK_ALPH - .word ptok_othr ; PTOK_OTHR - -; Data entry point for utility subroutines. -util_data: - - -; Program code. -.org lexer -lex: - ldx #0 ; Reset X. - txa ; Reset A. - phy #2 ; Preserve the screen buffer index. - txy ; Reset Y. - sty.q idx0 ; Clear the first index. - sty.q idx1 ; Clear the second index. - sty.q idx2 ; Clear the third index. -; lda (ptr), y ; Get a character from the line. -; pha #1 ; Preserve the character. -; jsr isdigit ; Is this character a digit? -; pla #1 ; Get the character back. -@getline: - lda #2 ; Get the third byte, of the line table address. - lsl #$10 ; Shift it by 2 bytes. - ldb #1 ; Set the second pointer - lda.w ltok ; to the last line. - jsr set_ptr ; - lda.w (ptr2) ; Get the next line. - jsr set_ptr ; Set the second pointer to the next line. - sta.w ctok ; Make it the current line. - and #0 ; Reset A. -@loop: - ldy.w idx0 ; Get the string index. - lda (ptr), y ; Get a character from the line. - jsr isdelm ; Get the delimiter. - cmp #1 ; Are we at the end of the line? - beq @end ; Yes, so we're done. -@spaces: - ldy.w idx0 ; Get the string index. - inc.w idx0 ; Increment the string index. - lda (ptr), y ; Get a character from the line. - pha #1 ; Preserve the character. - jsr isdelm ; Get the delimiter. - and #$10 ; Is this character, a space, or tab? - pla #1 ; Get the character back. - beq @isstart ; No, so check for the start of the line. - cmp #' ' ; Is this character, a space? - beq @incs ; Yes, so increment the starting space count. - cmp #'\t' ; No, but is it a tab? - beq @inct ; Yes, so increment the starting tab count. - jmp @spaces ; No, so keep looping. -@incs: - inc idx1 ; Increment the space count. - jmp @spaces ; Keep looping. -@inct: - inc idx1+1 ; Increment the tab count. - jmp @spaces ; Keep looping. -@isstart: - pha #2 ; Preserve the character. - lda.w idx1 ; Was there any whitespace? - pla #2 ; Get the character back. - beq @switch ; No, so start lexing. - cpb #1 ; Yes, and are we at the start of the line? - bne @switch ; No, so start lexing. -@whtspace: - ldy #2 ; Yes, so set the line index to the starting whitespace counters. - lda.w idx1 ; Get both indecies. - sta.w (ptr2), y ; Save them in the line. - and #0 ; Reset A. - sta.w idx1 ; Reset the second index. - deb ; Set the isstart flag to false. -@switch: - jsr get_ptok ; Get the pre-token. - jsr parse_ptok ; Parse the pre-token. - beq @end ; We got to the end of the string. - jmp @loop ; Keep looping. -@end: - ply #2 ; Get the screen buffer index back. - rts ; End of lex. - -parse_ptok: - pha #1 ; Preserve the pre-token. - ldb #2 ; Set the third pointer - lda.w #swtab ; to the start of the jump table. - jsr set_ptr ; - and #0 ; Reset A. - pla #1 ; Get the pre-token back. - phy #2 ; Preserve Y. - lsl #1 ; Multiply the pre-token by two, to get the jump index. - tay ; Get the index of the jump table. - lda.w (ptr3), y ; Get the address to jump to. - jsr set_ptr ; Set the third pointer to the case address. - and #0 ; Reset A. - tab ; Reset B. - ply #2 ; Get Y back. - jmp (ptr3) ; Jump to the case label. -ptok_dot: - rts ; End of parse_ptok. -ptok_at: - rts ; End of parse_ptok. -ptok_col: - rts ; End of parse_ptok. -ptok_equ: - rts ; End of parse_ptok. -ptok_plus: - rts ; End of parse_ptok. -ptok_min: - rts ; End of parse_ptok. -ptok_gt: - rts ; End of parse_ptok. -ptok_lt: - rts ; End of parse_ptok. -ptok_lbrk: - rts ; End of parse_ptok. -ptok_rbrk: - rts ; End of parse_ptok. -ptok_com: - rts ; End of parse_ptok. -ptok_xr: - rts ; End of parse_ptok. -ptok_yr: - rts ; End of parse_ptok. -ptok_dqu: - rts ; End of parse_ptok. -ptok_squ: - rts ; End of parse_ptok. -ptok_hash: - rts ; End of parse_ptok. -ptok_scol: - rts ; End of parse_ptok. -ptok_dolr: - rts ; End of parse_ptok. -ptok_prcn: - rts ; End of parse_ptok. -ptok_num: - rts ; End of parse_ptok. -ptok_alph: - rts ; End of parse_ptok. -ptok_othr: - rts ; End of parse_ptok. - - -; Entry point for utility subroutines. -utils: |