/*
 * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 *
 */

#include "ip_spec.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <em_spec.h>
#include <em_flag.h>

/* This program reads the human readable interpreter specification
 and produces a efficient machine representation that can be
 translated by a C-compiler.
 */

#define NOTAB   600    /* The max no of interpreter specs */
#define ESCAP   256

struct opform intable[NOTAB];
struct opform *lastform = intable - 1;

int nerror = 0;
int atend = 0;
int line = 1;
int maxinsl = 0;

extern char em_mnem[][4];
char esca[] = "escape";
#define ename(no)       ((no)==ESCAP?esca:em_mnem[(no)])

extern char em_flag[];


/* Forward declarations */
static int readchar(void);
static void pushback(int);
static void readin(void);
static char *ident(void);
static int getmnem(char *);
static void writeout(void);
static void checkall(void);
static void chkc(int, int, int);
static void ckop(int, int, int, int);
static int oplength(struct opform *);
static void check(int);
static int decflag(char *);
int compare(const void *, const void *);

static void error(char *format, ...);
static void mess(char *format, ...);
static void fatal(char *format, ...);



int main(int argc, char **argv)
{
	if (argc > 1)
	{
		if (freopen(argv[1], "r", stdin) == NULL)
		{
			fatal("Cannot open %s", argv[1]);
		}
	}
	if (argc > 2)
	{
		if (freopen(argv[2], "w", stdout) == NULL)
		{
			fatal("Cannot create %s", argv[2]);
		}
	}
	if (argc > 3)
	{
		fatal("%s [ file [ file ] ]", argv[0]);
	}
	atend = 0;
	readin();
	atend = 1;
	checkall();
	if (nerror == 0)
	{
		writeout();
	}
	exit(nerror);
}

static void readin(void)
{
	register struct opform *nextform;
	char *firstid;
	register int maxl;

	maxl = 0;
	for (nextform = intable; !feof(stdin) && nextform < &intable[NOTAB];)
	{
		firstid = ident();
		if (*firstid == '\n' || feof(stdin))
			continue;
		lastform = nextform;
		nextform->i_opcode = getmnem(firstid);
		nextform->i_flag = decflag(ident());
		switch (nextform->i_flag & OPTYPE)
		{
		case OPMINI:
		case OPSHORT:
			nextform->i_num = atoi(ident());
			break;
		}
		nextform->i_low = atoi(ident());
		if (*ident() != '\n')
		{
			int c;
			error("End of line expected");
			while ((c = readchar()) != '\n' && c != EOF)
				;
		}
		if (oplength(nextform) > maxl)
			maxl = oplength(nextform);
		nextform++;
	}
	if (!feof(stdin))
		fatal("Internal table too small");
	maxinsl = maxl;
}

static char *ident(void)
{
	/* skip spaces and tabs, anything up to space,tab or eof is
	 a identifier.
	 Anything from # to end-of-line is an end-of-line.
	 End-of-line is an identifier all by itself.
	 */

	static char array[200];
	register int c;
	register char *cc;

	do
	{
		c = readchar();
	} while (c == ' ' || c == '\t');
	for (cc = array; cc < &array[(sizeof array) - 1]; cc++)
	{
		if (c == '#')
		{
			do
			{
				c = readchar();
			} while (c != '\n' && c != EOF);
		}
		*cc = c;
		if (c == '\n' && cc == array)
			break;
		c = readchar();
		if (c == '\n')
		{
			pushback(c);
			break;
		}
		if (c == ' ' || c == '\t' || c == EOF)
			break;
	}
	*++cc = 0;
	return array;
}

static int getmnem(char *str)
{
	char (*ptr)[4];

	for (ptr = em_mnem; *ptr <= &em_mnem[sp_lmnem - sp_fmnem][0]; ptr++)
	{
		if (strcmp(*ptr, str) == 0)
			return (ptr - em_mnem);
	}
	error("Illegal mnemonic");
	return 0;
}

/* VARARGS1 */
static void error(char *format, ...)
{
    va_list argptr;
	if (!atend)
		fprintf(stderr, "line %d: ", line);
    va_start(argptr, format);
    vfprintf(stderr, format, argptr);
    va_end(argptr);
	fprintf(stderr, "\n");
	nerror++;
}

/* VARARGS1 */
static void mess(char *format, ...)
{
    va_list argptr;
	if (!atend)
		fprintf(stderr, "line %d: ", line);
    va_start(argptr, format);
    vfprintf(stderr, format, argptr);
    va_end(argptr);
	fprintf(stderr, "\n");
}

/* VARARGS1 */
static void fatal(char *format, ...)
{
    va_list argptr;
	if (!atend)
		fprintf(stderr, "line %d: ", line);
    va_start(argptr, format);
    vfprintf(stderr, format, argptr);
    va_end(argptr);
	fprintf(stderr, "\n");
	exit(EXIT_FAILURE);
}

#define ILLGL   -1

static void check(int val)
{
	if (val != ILLGL)
		error("Illegal flag combination");
}

static int decflag(char *str)
{
	int type;
	int escape;
	int range;
	int wordm;
	int notzero;

	type = escape = range = wordm = notzero = ILLGL;
	while (*str)
		switch (*str++)
		{
		case 'm':
			check(type);
			type = OPMINI;
			break;
		case 's':
			check(type);
			type = OPSHORT;
			break;
		case '-':
			check(type);
			type = OPNO;
			break;
		case '1':
			check(type);
			type = OP8;
			break;
		case '2':
			check(type);
			type = OP16;
			break;
		case '4':
			check(type);
			type = OP32;
			break;
		case '8':
			check(type);
			type = OP64;
			break;
		case 'u':
			check(type);
			type = OP16U;
			break;
		case 'e':
			check(escape);
			escape = 0;
			break;
		case 'N':
			check(range);
			range = 2;
			break;
		case 'P':
			check(range);
			range = 1;
			break;
		case 'w':
			check(wordm);
			wordm = 0;
			break;
		case 'o':
			check(notzero);
			notzero = 0;
			break;
		default:
			error("Unknown flag");
		}
	if (type == ILLGL)
		error("Type must be specified");
	switch (type)
	{
	case OP64:
	case OP32:
		if (escape != ILLGL)
			error("Conflicting escapes");
		escape = ILLGL;
	case OP16:
	case OP16U:
	case OP8:
	case OPSHORT:
	case OPNO:
		if (notzero != ILLGL)
			mess("Improbable OPNZ");
		if (type == OPNO && range != ILLGL)
		{
			mess("No operand in range");
		}
	}
	if (escape != ILLGL)
		type |= OPESC;
	if (wordm != ILLGL)
		type |= OPWORD;
	switch (range)
	{
	case ILLGL:
		type |= OP_BOTH;
		if (type == OPMINI || type == OPSHORT)
			error("Minies and shorties must have P or N");
		break;
	case 1:
		type |= OP_POS;
		break;
	case 2:
		type |= OP_NEG;
		break;
	}
	if (notzero != ILLGL)
		type |= OPNZ;
	return type;
}

static void writeout(void)
{
	register struct opform *next;
	int elem[sp_lmnem - sp_fmnem + 1 + 1];
	/* for each op points to first of descr. */
	register int i, currop;
	int nch;

	qsort(intable, (lastform - intable) + 1, sizeof intable[0], compare);

	printf("int\tmaxinsl\t= %d ;\n", maxinsl);
	currop = -1;
	nch = 0;
	printf("char opchoice[] = {\n");
	for (next = intable; next <= lastform; next++)
	{
		if ((next->i_opcode & 0377) != currop)
		{
			for (currop++; currop < (next->i_opcode & 0377); currop++)
			{
				elem[currop] = nch;
				error("Missing opcode %s", em_mnem[currop]);
			}
			elem[currop] = nch;
		}
		printf("%d, %d,", next->i_flag & 0377, next->i_low & 0377);
		nch += 2;
		switch (next->i_flag & OPTYPE)
		{
		case OPMINI:
		case OPSHORT:
			printf("%d,", next->i_num & 0377);
			nch++;
		}
		printf("\n");
	}
	for (currop++; currop <= sp_lmnem - sp_fmnem; currop++)
	{
		elem[currop] = nch;
		error("Missing opcode %s", em_mnem[currop]);
	}
	elem[sp_lmnem - sp_fmnem + 1] = nch;
	printf("0 } ;\n\nchar *opindex[] = {\n");
	for (i = 0; i < sp_lmnem - sp_fmnem + 1; i++)
	{
		printf(" &opchoice[%d], /* %d = %s */\n", elem[i], i, em_mnem[i]);
	}
	printf(" &opchoice[%d], /* %d = %s */\n", elem[sp_lmnem - sp_fmnem + 1],
			sp_lmnem - sp_fmnem + 1, "");
	printf("} ;\n");
}

int compare(const void *a1, const void *b1)
{
	struct opform *a = (struct opform *)(a1);
	struct opform *b = (struct opform *)(b1);

	if (a->i_opcode != b->i_opcode)
	{
		return (a->i_opcode & 0377) - (b->i_opcode & 0377);
	}
	return oplength(a) - oplength(b);
}

static int oplength(struct opform *a)
{
	int cnt;

	cnt = 1;
	if (a->i_flag & OPESC)
		cnt++;
	switch (a->i_flag & OPTYPE)
	{
	case OPNO:
	case OPMINI:
		break;
	case OP8:
	case OPSHORT:
		cnt++;
		break;
	case OP16U:
	case OP16:
		cnt += 2;
		break;
	case OP32:
		cnt += 5;
		break;
	case OP64:
		cnt += 9;
		break;
	}
	return cnt;
}

/* ----------- checking --------------*/

int ecodes[256], codes[256], lcodes[256];

#define NMNEM   (sp_lmnem-sp_fmnem+1)
#define MUST    1
#define MAY     2
#define FORB    3

char negc[NMNEM], zc[NMNEM], posc[NMNEM];

static void checkall(void)
{
	register int i, flag;
	register struct opform *next;
	int opc, low;

	for (i = 0; i < NMNEM; i++)
		negc[i] = zc[i] = posc[i] = 0;
	for (i = 0; i < 256; i++)
		lcodes[i] = codes[i] = ecodes[i] = -1;
	codes[254] = codes[255] = ESCAP;

	atend = 0;
	line = 0;
	for (next = intable; next <= lastform; next++)
	{
		line++;
		flag = next->i_flag & 0377;
		opc = next->i_opcode & 0377;
		low = next->i_low & 0377;
		chkc(flag, low, opc);
		switch (flag & OPTYPE)
		{
		case OPNO:
			zc[opc]++;
			break;
		case OPMINI:
		case OPSHORT:
			for (i = 1; i < ((next->i_num) & 0377); i++)
			{
				chkc(flag, low + i, opc);
			}
			if (!(em_flag[opc] & PAR_G) && (flag & OPRANGE) == OP_BOTH)
			{
				mess("Mini's and shorties should have P or N");
			}
			break;
		case OP8:
			error("OP8 is removed");
			break;
		case OP16:
			if (flag & OP_NEG)
				negc[opc]++;
			else if (flag & OP_POS)
				posc[opc]++;
			break;
		case OP16U:
		case OP32:
		case OP64:
			break;
		default:
			error("Illegal type");
			break;
		}
	}
	atend = 1;
	for (i = 0; i < 256; i++)
		if (codes[i] == -1)
		{
			mess("interpreter opcode %d not used", i);
		}
	for (opc = 0; opc < NMNEM; opc++)
	{
		switch (em_flag[opc] & EM_PAR)
		{
		case PAR_NO:
			ckop(opc, MUST, FORB, FORB);
			break;
		case PAR_C:
		case PAR_D:
		case PAR_F:
		case PAR_B:
			ckop(opc, FORB, MAY, MAY);
			break;
		case PAR_N:
		case PAR_G:
		case PAR_S:
		case PAR_Z:
		case PAR_O:
		case PAR_P:
			ckop(opc, FORB, MAY, FORB);
			break;
		case PAR_R:
			ckop(opc, FORB, MAY, FORB);
			break;
		case PAR_L:
			ckop(opc, FORB, MUST, MUST);
			break;
		case PAR_W:
			ckop(opc, MUST, MAY, FORB);
			break;
		default:
			error("Unknown instruction type of %s", ename(opc));
			break;
		}
	}
}

static void chkc(int flag, int icode, int emc)
{
	if (flag & OPESC)
	{
		if (ecodes[icode] != -1)
		{
			mess("Escaped opcode %d used by %s and %s", icode, ename(emc),
					ename(ecodes[icode]));
		}
		ecodes[icode] = emc;
	}
	else
		switch (flag & OPTYPE)
		{
		default:
			if (codes[icode] != -1)
			{
				mess("Opcode %d used by %s and %s", icode, ename(emc),
						ename(codes[icode]));
			}
			codes[icode] = emc;
			break;
		case OP32:
		case OP64:
			if (lcodes[icode] != -1)
			{
				mess("Long opcode %d used by %s and %s", icode, ename(emc),
						ename(codes[icode]));
			}
			lcodes[icode] = emc;
			break;
		}
}

static void ckop(int emc, int zf, int pf, int nf)
{
	if (zc[emc] > 1)
		mess("More then one OPNO for %s", ename(emc));
	if (posc[emc] > 1)
		mess("More then one OP16(pos) for %s", ename(emc));
	if (negc[emc] > 1)
		mess("More then one OP16(neg) for %s", ename(emc));
	switch (zf)
	{
	case MUST:
		if (zc[emc] == 0)
			mess("No OPNO for %s", ename(emc));
		break;
	case FORB:
		if (zc[emc] == 1)
			mess("Forbidden OPNO for %s", ename(emc));
		break;
	}
	switch (pf)
	{
	case MUST:
		if (posc[emc] == 0)
			mess("No OP16(pos) for %s", ename(emc));
		break;
	case FORB:
		if (posc[emc] == 1)
			mess("Forbidden OP16(pos) for %s", ename(emc));
		break;
	}
	switch (nf)
	{
	case MUST:
		if (negc[emc] == 0)
			mess("No OP16(neg) for %s", ename(emc));
		break;
	case FORB:
		if (negc[emc] == 1)
			mess("Forbidden OP16(neg) for %s", ename(emc));
		break;
	}
}

static int pushchar;
static int pushf;

static int readchar(void)
{
	int c;

	if (pushf)
	{
		pushf = 0;
		c = pushchar;
	}
	else
	{
		if (feof(stdin))
			return EOF;
		c = getc(stdin);
	}
	if (c == '\n')
		line++;
	return c;
}

static void pushback(int c)
{
	if (pushf)
	{
		fatal("Double pushback");
	}
	pushf++;
	pushchar = c;
	if (c == '\n')
		line--;
}