#include #include #include #include #include "symbol.h" #include "config.h" /* external functions */ void ReportError(char *filename, short linenr, int errnum); /* local functions */ long GetConstant(char *evalerr); int IndirectRegisters(void); int CheckRegister16(void); int CheckRegister8(void); int CheckCondition(void); enum symbols GetSym(void); void Skipline(void); /* global variables */ extern FILE *z80asmfile; extern char ident[]; extern char separators[]; extern enum symbols sym, ssym[]; extern short currentline; extern struct module *CURRENTMODULE; extern enum flag EOL; enum symbols GetSym(void) { char *instr; int c, chcount = 0; ident[0] = '\0'; if (EOL == ON) { sym = newline; return sym; } for (;;) { /* Ignore leading white spaces, if any... */ c = fgetc(z80asmfile); if ((c == '\n') || (c == EOF) || (c == '\x1A') ) { sym = newline; EOL = ON; return newline; } else if (!isspace(c)) break; } instr = strchr(separators, c); if (instr != NULL) { sym = ssym[instr - separators]; /* index of found char in separators[] */ if (sym == semicolon) { Skipline(); /* ignore comment line, prepare for next line */ sym=newline; } return sym; } ident[chcount++] = (char) toupper(c); switch (c) { case '$': sym = hexconst; break; case '@': sym = binconst; break; case '#': sym = name; break; default: if (isdigit(c)) sym = decmconst; /* a decimal number found */ else { if (isalpha(c)) sym = name; /* an identifier found */ else sym = nil; /* rubbish ... */ } break; } /* Read identifier until space or legal separator is found */ if (sym == name) { for (;;) { c = fgetc(z80asmfile); if ((!iscntrl(c)) && (strchr(separators, c) == NULL)) { if (!isalnum(c)) { if (c != '_') { sym = nil; break; } else ident[chcount++] = '_'; /* underscore in identifier */ } else ident[chcount++] = (char) toupper(c); } else { ungetc(c, z80asmfile); /* puch character back into stream for next read */ break; } } } else for (;;) { c = fgetc(z80asmfile); if (!iscntrl(c) && (strchr(separators, c) == NULL)) ident[chcount++] = c; else { ungetc(c, z80asmfile); /* puch character back into stream for next read */ break; } } ident[chcount] = '\0'; return sym; } void Skipline(void) { if (EOL == OFF) { while (fgetc(z80asmfile) != '\n'); /* get to beginning of next line... */ EOL = ON; } } int CheckCondition(void) { switch (*ident) { case 'Z': /* is it zero flag ? */ if (*(ident + 1) == '\0') return (1); else return -1; case 'N': /* is it NZ, NC ? */ if (*(ident + 2) == '\0') switch (*(ident + 1)) { case 'Z': return (0); case 'C': return (2); default: return (-1); } else return -1; case 'C': /* is it carry flag ? */ if (*(ident + 1) == '\0') return (3); else return -1; case 'P': switch (*(ident + 1)) { case '\0': return (6); /* P */ case 'O': if (*(ident + 2) == '\0') return (4); /* PO */ else return -1; case 'E': if (*(ident + 2) == '\0') return (5); /* PO */ else return (-1); default: return (-1); } case 'M': /* is it minus flag ? */ if (*(ident + 1) == '\0') return (7); else return -1; default: return -1; } } int CheckRegister8(void) { if (sym == name) if (*(ident + 1) == '\0') { switch (*ident) { case 'A': return 7; case 'H': return 4; case 'B': return 0; case 'L': return 5; case 'C': return 1; case 'D': return 2; case 'E': return 3; case 'I': return 8; case 'R': return 9; case 'F': return 6; } } else { if (strcmp(ident,"IXL") == 0) return (8+5); else if (strcmp(ident,"IXH") == 0) return (8+4); else if (strcmp(ident,"IYL") == 0) return (16+5); else if (strcmp(ident,"IYH") == 0) return (16+4); } return -1; } int CheckRegister16(void) { if (sym == name) if (*(ident + 2) == '\0') switch (*ident) { case 'H':if (*(ident + 1) == 'L') return (2); break; case 'B': if (*(ident + 1) == 'C') return (0); break; case 'D': if (*(ident + 1) == 'E') return (1); break; case 'A': if (*(ident + 1) == 'F') return (4); break; case 'S': if (*(ident + 1) == 'P') return (3); break; case 'I': switch (*(ident + 1)) { case 'X': return (5); case 'Y': return (6); } } return -1; } /* * This function will parse the current line for an indirect addressing mode. The return code can be: * * 0 - 2 : (BC); (DE); (HL) 5,6 : (IX <+|- expr.> ); (IY <+|- expr.> ) 7 : (nn), nn = 16bit address * expression * * The function also returns a pointer to the parsed expression, now converted to postfix. */ int IndirectRegisters(void) { int reg16; GetSym(); reg16 = CheckRegister16(); switch (reg16) { case 0: /* 0 to 2 = BC, DE, HL */ case 1: case 2: if (GetSym() == rparen) { /* (BC) | (DE) | (HL) | ? */ GetSym(); return (reg16); /* indicate (BC), (DE), (HL) */ } else { ReportError(CURRENTFILE->fname, CURRENTFILE->line, 1); /* Right bracket missing! */ return -1; } case 5: /* 5, 6 = IX, IY */ case 6: GetSym(); /* prepare expression evaluation */ return (reg16); case -1: /* sym could be a '+', '-' or a symbol... */ return 7; default: ReportError(CURRENTFILE->fname, CURRENTFILE->line, 11); return -1; } } long GetConstant(char *evalerr) { long size, l, intresult = 0; unsigned short bitvalue = 1; *evalerr = 0; /* preset to no errors */ if ((sym != hexconst) && (sym != binconst) && (sym != decmconst)) { *evalerr = 1; return (0); /* syntax error - illegal constant definition */ } size = strlen(ident); if (sym != decmconst) if ((--size) == 0) { *evalerr = 1; return (0); /* syntax error - no constant specified */ } switch (ident[0]) { case '@': if (size > 8) { *evalerr = 1; return (0); /* max 8 bit */ } for (l = 1; l <= size; l++) if (strchr("01", ident[l]) == NULL) { *evalerr = 1; return (0); } /* convert ASCII binary to integer */ for (l = size; l >= 1; l--) { if (ident[l] == '1') intresult += bitvalue; bitvalue <<= 1; /* logical shift left & 16 bit 'adder' */ } return (intresult); case '$': for (l = 1; l <= size; l++) if (isxdigit(ident[l]) == 0) { *evalerr = 1; return (0); } sscanf((char *) (ident + 1), "%lx", &intresult); return (intresult); default: for (l = 0; l <= (size - 1); l++) if (isdigit(ident[l]) == 0) { *evalerr = 1; return (0); } return (atol(ident)); } }