view lwasm/insn_gen.c @ 393:f2decd9b276d

Fix minor error in string parsing Growing a buffer by 32 bytes and then only saying the buffer grew by one byte is not exactly efficient. While not strictly broken, it's dumb. Fix it to actually count the 32 bytes.
author William Astle <lost@l-w.ca>
date Tue, 14 Jul 2015 23:12:24 -0600
parents 2d9b7ae6c329
children b20f14edda5a
line wrap: on
line source

/*
insn_gen.c, Copyright © 2009 William Astle

This file is part of LWASM.

LWASM is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.

You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.

Contains code for parsing general addressing modes (IMM+DIR+EXT+IND)
*/

#include <ctype.h>
#include <stdlib.h>

#include <lw_expr.h>

#include "lwasm.h"
#include "instab.h"

void insn_indexed_parse_aux(asmstate_t *as, line_t *l, char **p);
void insn_indexed_resolve_aux(asmstate_t *as, line_t *l, int force, int elen);
void insn_indexed_emit_aux(asmstate_t *as, line_t *l);

void insn_parse_indexed_aux(asmstate_t *as, line_t *l, char **p);
void insn_resolve_indexed_aux(asmstate_t *as, line_t *l, int force, int elen);

// "extra" is required due to the way OIM, EIM, TIM, and AIM work
void insn_parse_gen_aux(asmstate_t *as, line_t *l, char **p, int elen)
{
	const char *optr2;
	int v1, tv;
	lw_expr_t s;

	if (!**p)
	{
		lwasm_register_error(as, l, E_OPERAND_BAD);
		return;
	}

	optr2 = *p;
	while (*optr2 && !isspace(*optr2) && *optr2 != ',') optr2++
		/* do nothing */ ;

	if (*optr2 == ',' || **p == '[')
	{
		l -> lint = -1;
		l -> lint2 = 1;
		insn_parse_indexed_aux(as, l, p);
		l -> minlen = OPLEN(instab[l -> insn].ops[1]) + 1 + elen;
		l -> maxlen = OPLEN(instab[l -> insn].ops[1]) + 3 + elen;
		goto out;
	}

	if (**p == '<')
	{
		(*p)++;
		l -> lint2 = 0;
	}

	// for compatibility with asxxxx
	// * followed by a digit, alpha, or _, or ., or ?, or another * is "f8"
	else if (**p == '*')
	{
		tv = *(*p + 1);
		if (isdigit(tv) || isalpha(tv) || tv == '_' || tv == '.' || tv == '?' || tv == '@' || tv == '*' || tv == '+' || tv == '-')
		{
			l -> lint2 = 0;
			(*p)++;
		}
	}
	else if (**p == '>')
	{
		(*p)++;
		l -> lint2 = 2;
	}
	else
	{
		l -> lint2 = -1;
	}

	l -> minlen = OPLEN(instab[l -> insn].ops[0]) + 1 + elen;
	l -> maxlen = OPLEN(instab[l -> insn].ops[2]) + 2 + elen;
	s = lwasm_parse_expr(as, p);
	if (!s)
	{
		lwasm_register_error(as, l, E_OPERAND_BAD);
		return;
	}
	
	lwasm_save_expr(l, 0, s);

	if (as -> output_format == OUTPUT_OBJ && l -> lint2 == -1)
	{
		l -> lint2 = 2;
		goto out;
	}

	if (l -> lint2 != -1)
		goto out;

	// if we have a constant now, figure out dp vs nondp
	if (lw_expr_istype(s, lw_expr_type_int))
	{
		if (s -> value > 0xffff) lwasm_register_error(as, l, E_BYTE_OVERFLOW);

		v1 = lw_expr_intval(s);
		if (((v1 >> 8) & 0xff) == (l -> dpval & 0xff))
		{
			l -> lint2 = 0;
			goto out;
		}
		l -> lint2 = 2;
	}
	else
	{
		int min;
		int max;
		
		if (lwasm_calculate_range(as, s, &min, &max) == 0)
		{
//			fprintf(stderr, "range (P) %d...%d for %s\n", min, max, lw_expr_print(s));
			if (min > max)
			{
				// we don't know what to do in this case so don't do anything
				goto out;
			}
			min = (min >> 8) & 0xff;
			max = (max >> 8) & 0xff;
			if ((l -> dpval & 0xff) < min || (l -> dpval & 0xff) > max)
			{
				l -> lint2 = 2;
				goto out;
			}
			if (min == max && (l -> dpval & 0xff) == min)
			{
				l -> lint2 = 0;
				goto out;
			}
			// if here, we don't know if the value is in the DP or not
			{
				l -> lint2 = -1;
				goto out;
			}
		}
	}

out:
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1 + elen;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2 + elen;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1 + elen;
		}
	}
}

void insn_resolve_gen_aux(asmstate_t *as, line_t *l, int force, int elen)
{
	lw_expr_t e;
	
	if (l -> lint2 == 1)
	{
		// indexed
		insn_resolve_indexed_aux(as, l, force, elen);
		goto out;
	}
	
	if (l -> lint2 != -1)
		return;
	
	e = lwasm_fetch_expr(l, 0);
	lwasm_reduce_expr(as, e);
	if (lw_expr_istype(e, lw_expr_type_int))
	{
		int v;
		
		v = lw_expr_intval(e);

		if (((v >> 8) & 0xff) == (l -> dpval & 0xff))
		{
			l -> lint2 = 0;
			goto out;
		}
		l -> lint2 = 2;
		goto out;
	}
	else
	{
		int min;
		int max;
		
		if (lwasm_calculate_range(as, e, &min, &max) == 0)
		{
//			fprintf(stderr, "range (R) %d...%d for %s\n", min, max, lw_expr_print(e));
			if (min > max)
			{
				// we don't know what to do in this case so don't do anything
				goto out;
			}
			min = (min >> 8) & 0xff;
			max = (max >> 8) & 0xff;
			if ((l -> dpval & 0xff) < min || (l -> dpval & 0xff) > max)
			{
				l -> lint2 = 2;
				goto out;
			}
			if (min == max && (l -> dpval & 0xff) == min)
			{
				l -> lint2 = 0;
				goto out;
			}
			// if here, we don't know if the value is in the DP or not
			{
				l -> lint2 = -1;
				goto out;
			}
		}
	}

	if (force)
	{
		l -> lint2 = 2;
	}

out:
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1 + elen;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2 + elen;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1 + elen;
		}
	}
}

void insn_emit_gen_aux(asmstate_t *as, line_t *l, int extra)
{
	lw_expr_t e;
	
	e = lwasm_fetch_expr(l, 0);
	lwasm_emitop(l, instab[l -> insn].ops[l -> lint2]);
	
	if (extra != -1)
		lwasm_emit(l, extra);
	
	if (l -> lint2 == 1)
	{
		lwasm_emit(l, l -> pb);
		if (l -> lint > 0)
		{
			int i;
			i = lw_expr_intval(e);
			if (l -> lint == 1)
			{
				if (i < -128 || i > 127)
					lwasm_register_error(as, l, E_BYTE_OVERFLOW);
			}
			lwasm_emitexpr(l, e, l -> lint);
		}

		l -> cycle_adj = lwasm_cycle_calc_ind(l);
		return;
	}
	
	if (l -> lint2 == 2)
		lwasm_emitexpr(l, e, 2);
	else
		lwasm_emitexpr(l, e, 1);
}

// the various insn_gen? functions have an immediate mode of ? bits
PARSEFUNC(insn_parse_gen0)
{
	if (**p == '#')
	{
		lwasm_register_error(as, l, E_IMMEDIATE_INVALID);
		return;
	}
	
	// handle non-immediate
	insn_parse_gen_aux(as, l, p, 0);
}

RESOLVEFUNC(insn_resolve_gen0)
{
	if (l -> len != -1)
		return;

	// handle non-immediate
	insn_resolve_gen_aux(as, l, force, 0);
}

EMITFUNC(insn_emit_gen0)
{
	insn_emit_gen_aux(as, l, -1);
}

PARSEFUNC(insn_parse_gen8)
{
	l -> genmode = 8;
	if (**p == '#')
	{
		lw_expr_t e;
		
		(*p)++;
		as -> exprwidth = 8;
		e = lwasm_parse_expr(as, p);
		as -> exprwidth = 16;
		if (!e)
		{
			lwasm_register_error(as, l, E_OPERAND_BAD);
			return;
		}
		l -> len = OPLEN(instab[l -> insn].ops[3]) + 1;
		l -> lint2 = 3;
		lwasm_save_expr(l, 0, e);
		return;
	}
	
	// handle non-immediate
	insn_parse_gen_aux(as, l, p, 0);
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1;
		}
	}
}

RESOLVEFUNC(insn_resolve_gen8)
{
	if (l -> len != -1)
		return;

	// handle non-immediate
	insn_resolve_gen_aux(as, l, force, 0);
}

EMITFUNC(insn_emit_gen8)
{
	if (l -> lint2 == 3)
	{
		lw_expr_t e;
		e = lwasm_fetch_expr(l, 0);
		if (lw_expr_istype(e, lw_expr_type_int))
		{
			int i;
			i = lw_expr_intval(e);
			if (i < -128 || i > 255)
			{
				lwasm_register_error(as, l, E_BYTE_OVERFLOW);
			}
		}

		lwasm_emitop(l, instab[l -> insn].ops[3]);
		lwasm_emitexpr(l, e, 1);
		return;
	}

	insn_emit_gen_aux(as, l, -1);
}

PARSEFUNC(insn_parse_gen16)
{
	l -> genmode = 16;
	if (**p == '#')
	{
		lw_expr_t e;
		
		(*p)++;
		e = lwasm_parse_expr(as, p);
		if (!e)
		{
			lwasm_register_error(as, l, E_OPERAND_BAD);
			return;
		}
		l -> len = OPLEN(instab[l -> insn].ops[3]) + 2;
		l -> lint2 = 3;
		lwasm_save_expr(l, 0, e);
		return;
	}
	
	// handle non-immediate
	insn_parse_gen_aux(as, l, p, 0);
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1;
		}
	}
}

RESOLVEFUNC(insn_resolve_gen16)
{
	if (l -> len != -1)
		return;

	// handle non-immediate
	insn_resolve_gen_aux(as, l, force, 0);
}

EMITFUNC(insn_emit_gen16)
{
	if (l -> lint2 == 3)
	{
		lw_expr_t e;
		e = lwasm_fetch_expr(l, 0);
		lwasm_emitop(l, instab[l -> insn].ops[3]);
		lwasm_emitexpr(l, e, 2);
		return;
	}

	insn_emit_gen_aux(as, l, -1);
}

PARSEFUNC(insn_parse_gen32)
{
	l -> genmode = 32;
	if (**p == '#')
	{
		lw_expr_t e;
		
		(*p)++;
		e = lwasm_parse_expr(as, p);
		if (!e)
		{
			lwasm_register_error(as, l, E_OPERAND_BAD);
			return;
		}
		l -> len = OPLEN(instab[l -> insn].ops[3]) + 4;
		l -> lint2 = 3;
		lwasm_save_expr(l, 0, e);
		return;
	}
	
	// handle non-immediate
	insn_parse_gen_aux(as, l, p, 0);
	if (l -> lint2 != -1)
	{
		if (l -> lint2 == 0)
		{
			l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
		}
		else if (l -> lint2 == 2)
		{
			l -> len = OPLEN(instab[l -> insn].ops[2]) + 2;
		}
		else if (l -> lint2 == 1 && l -> lint != -1)
		{
			l -> len = OPLEN(instab[l -> insn].ops[1]) + l -> lint + 1;
		}
	}
}

RESOLVEFUNC(insn_resolve_gen32)
{
	if (l -> len != -1)
		return;

	// handle non-immediate
	insn_resolve_gen_aux(as, l, force, 0);
}

EMITFUNC(insn_emit_gen32)
{
	if (l -> lint2 == 3)
	{
		lw_expr_t e;
		e = lwasm_fetch_expr(l, 0);
		lwasm_emitop(l, instab[l -> insn].ops[3]);
		lwasm_emitexpr(l, e, 4);
		return;
	}

	insn_emit_gen_aux(as, l, -1);
}

PARSEFUNC(insn_parse_imm8)
{
	lw_expr_t e;
	
	if (**p == '#')
	{
		(*p)++;

		as -> exprwidth = 8;
		e = lwasm_parse_expr(as, p);
		as -> exprwidth = 16;
		if (!e)
		{
			lwasm_register_error(as, l, E_OPERAND_BAD);
			return;
		}
		l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
		lwasm_save_expr(l, 0, e);
	}
	else
	{
		lwasm_register_error(as, l, E_OPERAND_BAD);
	}
}

EMITFUNC(insn_emit_imm8)
{
	lw_expr_t e;
	
	lwasm_emitop(l, instab[l -> insn].ops[0]);
	e = lwasm_fetch_expr(l, 0);
	if (lw_expr_istype(e, lw_expr_type_int))
	{
		int i;
		i = lw_expr_intval(e);
		if (i < -128 || i > 255)
		{
			lwasm_register_error(as, l, E_BYTE_OVERFLOW);
		}
	}
	lwasm_emitexpr(l, e, 1);
}