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C02/parse.c
2018-02-13 17:25:57 -05:00

472 lines
12 KiB
C

/*************************************
* C02 Input File Parsing Routines *
*************************************/
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <errno.h>
#include "common.h"
#include "files.h"
#include "asm.h"
#include "parse.h"
/* Various tests against nxtchr */
int match(char c) {return TF(nxtchr == c);}
int inbtwn(char mn, char mx) {return TF(nxtchr >= mn && nxtchr <= mx);}
int isalph() {return isalpha(nxtchr);}
int isanum() {return isalnum(nxtchr);}
int isapos() {return match('\'');}
int isbin() {return inbtwn('0', '1');}
int isbpre() {return TF(isnpre() || isapos());}
int iscpre() {return TF(isbpre() || ishash());}
int isdec() {return inbtwn('0', '9');}
int ishash() {return match('#');}
int ishexd() {return TF(isdec() || inbtwn('A', 'Z'));}
int isnl() {return TF(match('\n') || match('\r'));}
int isnpre() {return TF(isdec() || match('$') || match('%'));}
int isoper() {return TF(strchr("+-&|^", nxtchr));}
int ispopr() {return TF(strchr("+-<>", nxtchr));}
int isprnt() {return isprint(nxtchr);}
int isspc() {return isspace(nxtchr);}
int isvpre() {return TF(isalph() || iscpre());}
int isxpre() {return TF(isvpre() || match('-'));}
/* Conversion Functions */
char invchr(char c) {return isalpha(c)?(islower(c)?toupper(c):tolower(c)):c;}
/* if Word is s then return TRUE else return FALSE*/
int wordis(char *s)
{
return strcmp(word, s) == 0;
}
/* Get Next Character from Current Input File *
* Uses: inpfil - Input File Handle *
* Sets: nxtchr - Next Character in Source File */
char getnxt()
{
int i;
int wascr = match('\r');
char c = nxtchr;
//if (nxtwrd[nxtptr]) //If nxtwrd is set
// nxtchr = nxtwrd[nxtptr++]; // Pop First Character from nxtwrd
//else
nxtchr = fgetc(inpfil);
nxtupc = toupper(nxtchr);
if (wascr && match('\n')) return c; //Skip NL after CR
if (isnl()) curcol=1; else curcol++;
if (curcol == 1) curlin++;
return c;
}
/* Advance Input File to next printable character */
void skpspc()
{
//DEBUG("Skipping Spaces\n", 0);
if (isspc()) CCMNT(' ');
while (isspc())
getnxt();
}
/* Check if the next printable character is c *
* and advance past it if it is *
* Returns TRUE is character is found, *
* otherwise FALSE */
int look(char c)
{
int found;
skpspc();
found = match(c);
if (found) {
skpchr();
CCMNT(c);
}
return found;
}
/* if next printable character is c then skip, else generate error */
void expect(char c)
{
if (c == 0) return;
if (look(c)) return;
else {
fprintf(stderr, "Expected Character '%c', but found '%c'\n", c, nxtchr);
exterr(EXIT_FAILURE);
}
}
/* Advance Input File to next printable character */
void skpchr() {char skip = getnxt();}
/* Advance Input File to end of line */
void skpeol() {while (!isnl()) getnxt();}
/* Advance Source File to end of comment *
* Recognizes both C and C++ style comments */
void skpcmt()
{
DEBUG("Skipping Comment\n", 0);
skpchr(); //skip initial /
if (match('/')) //if C style comment
skpeol(); // skip rest of line
else if (match('*')) //if C++ style comment
while (TRUE) // skip to */
{
skpchr();
if (!match('*')) continue;
while (match('*')) skpchr();
if (!match('/')) continue;
skpchr();
break;
//todo: add code to catch unterminated comment
}
else //if neither
expctd("/ or *"); // error out
}
/* Reads next Word in current Input File, where *
* a Word is a sequence of AlphaNumeric characters *
* Sets: word - the Word read from the source file */
void getwrd()
{
int wrdlen = 0;
skpspc();
if (!isalph()) expctd("Alphabetic Character");
while (isanum())
{
word[wrdlen++] = toupper(getnxt());
}
word[wrdlen] = 0;
}
/* Escape Character */
char escape(char c)
{
DEBUG("Escaping character '%c'\n", c);
switch (c) {
case 'r': return 0x0d;
default: return c;
}
}
/* Get String */
void getstr() {
char strdel, tmpchr;
int wrdlen = 0, escnxt = FALSE;
DEBUG("Parsing string\n", 0);
strdel = getnxt(); //Get String Delimiter
CCMNT(strdel);
while(match(strdel) == escnxt) {
CCMNT(nxtchr);
if (escnxt) {
word[wrdlen++] = escape(getnxt());
escnxt = FALSE;
}
else {
if (match('\\'))
escnxt = TRUE;
else
if (invasc) nxtchr = invchr(nxtchr);
word[wrdlen++] = nxtchr;
skpchr();
}
}
skpchr(); //Skip End Delimiter
CCMNT(strdel);
word[wrdlen++] = 0;
}
/* Read Binary number from input file *
* a Binary is a series of binary digits (0 or 1) *
* prefixed with '%' *
* Sets: word - binary number including leading '%' *
* Returns: integer value of number */
int prsbin()
{
int wrdlen = 0;
int digit;
int number = 0;
if (!match('%'))
expctd("hexadecimal number");
word[wrdlen++] = nxtchr;
getnxt();
while (isbin()) {
word[wrdlen++] = nxtchr;
digit = nxtchr - '0';
number = number * 2 + digit;
skpchr();
}
word[wrdlen] = 0;
return (number);
}
/* Read Decimal number from input file *
* a Decimal is a series of digits (0-9) *
* Sets: word - number without leading 0's *
* Returns: integer value of number */
int prsdec()
{
int wrdlen = 0;
int digit;
int number = 0;
if (!isdec()) expctd("Digit");
while (isdec())
{
if (!match('0') || number != 0) //skip leading zeros
word[wrdlen++] = nxtchr;
digit = getnxt() - '0';
number = number * 10 + digit;
}
if (number == 0) word[wrdlen++] = '0';
word[wrdlen] = 0;
return(number);
}
/* Reads Hexadecimal number from input file *
* Sets: word - Hex number including leading '$' *
* Returns: integer value of number */
int prshex()
{
int wrdlen = 0;
int digit;
int number = 0;
DEBUG("Parsing hexadecimal constant '", 0);
if (!match('$'))
expctd("hexadecimal number");
word[wrdlen++] = getnxt();
while (ishexd()) {
DETAIL("%c", nxtchr);
word[wrdlen++] = nxtchr;
if (isdec())
digit = nxtchr - '0';
else
digit = nxtchr - 'A' + 10;
number = number * 16 + digit;
skpchr();
}
DETAIL("'\n", 0);
word[wrdlen] = 0;
return (number);
}
/* Reads Character constant from input file *
* Sets: word - Character constant including *
* single quotes *
* Returns: ASCII value of constant */
int prschr()
{
int wrdlen = 0;
char c;
DEBUG("Parsing character constant\n", 0);
expect('\'');
word[wrdlen++] = '\'';
if (match('\\'))
word[wrdlen++] = getnxt();
c = getnxt();
DEBUG("Extracted character %c\n", c);
if (invasc) c = invchr(c);
word[wrdlen++] = c;
expect('\'');
word[wrdlen++] = '\'';
word[wrdlen] = 0;
return (int)c;
}
/* Parse numeric value *
* Args: maxval - maximum allowed value *
* Sets: value - parsed number (as string) *
* Returns: parsed number */
int prsnum(int maxval)
{
int number;
skpspc();
if (!isbpre()) expctd("constant value");
switch(nxtchr) {
case '%':
number = prsbin();
break;
case '$':
number = prshex();
break;
case '\'':
number = prschr();
break;
default:
number = prsdec();
}
DEBUG("Parsed number '%s' ", word);
DETAIL("with value '%d'\n", number);
if (number > maxval) {
ERROR("Out of bounds constant '%d';\n", number, EXIT_FAILURE);
}
if (maxval > 255)
sprintf(value, "$%04X", number);
else
sprintf(value, "$%02X", number);
return number;
}
/* Parse Nuneric Byte Value */
int prsbyt()
{
return prsnum(0xFF);
}
/* Find Defined Constant */
void fnddef(char *name)
{
DEBUG("Looking up defined constant '%s'\n", word);
for (defidx=0; defidx<defcnt; defidx++) {
if (strcmp(defnam[defidx], name) == 0)
return;
}
defidx = -1;
}
/* Parse Definition */
int prsdef()
{
expect('#');
getwrd(); //Get Constant Name
fnddef(word);
if (defidx < 0) {
ERROR("Undefined constant '%s'\n", word, EXIT_FAILURE);
}
strcpy(value, word);
return defval[defidx];
}
/* Parse numeric constant *
* Args: maxval - maximum allowed value *
* Sets: cnstnt - the constant (as an integer) *
* value - the constant (as asm arg) *
* valtyp - value type (CONSTANT) *
* word - constant (as a string) *
* Note: Value is converted to hexadecimal *
* because DASM uses the format 'c for *
* character arguments instead of 'c' */
void prscon()
{
skpspc();
if (ishash())
cnstnt = prsdef();
else
cnstnt = prsbyt();
valtyp = CONSTANT;
ACMNT(word);
strcpy(word, value); //Patch for DASM
strcpy(value, "#");
strcat(value, word);
DEBUG("Generated constant '%s'\n", value);
}
/* Get Value Type */
int gettyp()
{
if (match('(')) return FUNCTION;
else if (match('[')) return ARRAY;
else return VARIABLE;
}
/* Parse arithmetic or bitwise operator */
void prsopr()
{
if (!isoper)
expctd("Arithmetic or bitwise operator");
oper = getnxt();
DEBUG("Parsed operator '%c'\n", oper);
CCMNT(oper);
skpspc();
}
/* Process Array Index */
void prcidx(char *name, char *index)
{
if (strlen(index)) {
asmlin("LDX", index);
strcat(name,",X");
}
}
/* Generate Post-Operation Error */
void poperr(char* name)
{
fprintf(stderr, "Illegal post-operation %c%c on register %s\n", oper, oper, name);
exterr(EXIT_FAILURE);
}
/* Process Post Operator */
void prcpst(char* name, char *index)
{
DEBUG("Processing post operation '%c'\n", oper);
prcidx(name, index);
switch(oper)
{
case '+':
if (strcmp(name, "X")==0)
asmlin("INX", "");
else if (strcmp(name, "Y")==0)
asmlin("INY", "");
else if (strcmp(name, "A")==0)
poperr(name); //65C02 supports implicit INC, 6502 does not
else
asmlin("INC", name);
break;
case '-':
if (strcmp(name, "X")==0)
asmlin("DEX", "");
else if (strcmp(name, "Y")==0)
asmlin("DEY", "");
else if (strcmp(name, "A")==0)
poperr(name); //65C02 supports implicit DEC, 6502 does not
else
asmlin("DEC", name);
break;
case '<':
if (strcmp(name, "X")==0)
poperr(name); //Index Register Shift not Supported
else if (strcmp(name, "Y")==0)
poperr(name); //Index Register Shift not Supported
else if (strcmp(name, "A")==0)
asmlin("ASL", "");
else
asmlin("ASL", name);
break;
case '>':
if (strcmp(name, "X")==0)
poperr(name); //Index Register Shift not Supported
else if (strcmp(name, "Y")==0)
poperr(name); //Index Register Shift not Supported
else if (strcmp(name, "A")==0)
asmlin("LSR", "");
else
asmlin("LSR", name);
break;
default:
fprintf(stderr, "Unrecognized post operator '%c'\n", oper);
exterr(EXIT_FAILURE);
}
}
/* Parse Post Operator */
int prspst(char trmntr, char* name, char* index) {
oper = getnxt();
CCMNT(oper);
DEBUG("Checking for post operation '%c'\n", oper);
if (nxtchr == oper) {
skpchr();
CCMNT(oper);
expect(trmntr);
prcpst(name, index); //Process Post-Op
oper = 0;
}
else {
DEBUG("Not a post operation\n", 0);
}
return oper;
}