exgram.h

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1989-2012 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*          http://www.eclipse.org/org/documents/epl-v10.html           *
*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <[email protected]>                  *
*                                                                      *
***********************************************************************/
#pragma prototyped

/*
 * grammar support routines
 * stuffed in a header so exparse.y can work
 * with both yacc and bison
 * sometimes free stuff can cost a lot
 */

#if !defined(_EXGRAM_H) && ( defined(MINTOKEN) || defined(YYTOKENTYPE) )
#define _EXGRAM_H

#if !defined(_EXPARSE_H)
#define _EXPARSE_H
#endif

#include "exlib.h"

#define exlex()		extoken(expr.program)

#define ALLOCATE(p,x)	(x*)exalloc(p,sizeof(x))
#define QUALIFY(r,s)	((r)&&(expr.program->disc->flags&EX_QUALIFY)?qualify(r,s):(s))

static int		a2t[] = { 0, FLOATING, INTEGER, STRING };
static Switch_t		swstate;

Exstate_t		expr;

/*
 * allocate and initialize a new expression node in the current program
 */

Exnode_t*
exnewnode(Expr_t* p, int op, int binary, int type, Exnode_t* left, Exnode_t* right)
{
	register Exnode_t*	x;

	x = ALLOCATE(p, Exnode_t);
	x->op = op;
	x->type = type;
	x->binary = binary;
	x->local.number = 0;
	x->local.pointer = 0;
	x->data.operand.left = left;
	x->data.operand.right = right;
	return x;
}

/*
 * free node x and its children
 */

void
exfreenode(Expr_t* p, register Exnode_t* x)
{
	register Print_t*	pr;
	register Exref_t*	r;
	Print_t*		pn;
	Exref_t*		rn;
	int			i;

	switch (x->op)
	{
	case CALL:
		if (x->data.call.args)
			exfreenode(p, x->data.call.args);
		break;
	case CONSTANT:
		break;
	case DEFAULT:
		if (x->data.select.next)
			exfreenode(p, x->data.select.next);
		break;
	case DYNAMIC:
		if (x->data.variable.index)
			exfreenode(p, x->data.variable.index);
		if (x->data.variable.symbol->local.pointer)
		{
			dtclose((Dt_t*)x->data.variable.symbol->local.pointer);
			x->data.variable.symbol->local.pointer = 0;
		}
		break;
	case ITERATE:
		if (x->data.generate.statement)
			exfreenode(p, x->data.generate.statement);
		break;
	case ID:
		rn = x->data.variable.reference;
		while (r = rn)
		{
			rn = r->next;
			vmfree(p->vm, r);
		}
		if (x->data.variable.index)
			exfreenode(p, x->data.variable.index);
		break;
	case PRINTF:
	case SPRINTF:
		if (x->data.print.descriptor)
			exfreenode(p, x->data.print.descriptor);
		pn = x->data.print.args;
		while (pr = pn)
		{
			for (i = 0; i < elementsof(pr->param) && pr->param[i]; i++)
				exfreenode(p, pr->param[i]);
			if (pr->arg)
				exfreenode(p, pr->arg);
			pn = pr->next;
			vmfree(p->vm, pr);
		}
		break;
	default:
		if (x->data.operand.left)
			exfreenode(p, x->data.operand.left);
		if (x->data.operand.right)
			exfreenode(p, x->data.operand.right);
		break;
	}
	vmfree(p->vm, x);
}

/*
 * cast x to type
 */

static char*	typename[] =
{
	"external", "integer", "unsigned", "float", "string"
};

static int	typecast[5][5] =
{
	0,	X2I,	X2I,	X2F,	X2S,
	I2X,	0,	0,	I2F,	I2S,
	I2X,	0,	0,	I2F,	I2S,
	F2X,	F2I,	F2I,	0,	F2S,
	S2X,	S2I,	S2I,	S2F,	0
};

#define TYPEINDEX(t)	(((t)>=INTEGER&&(t)<=STRING)?((t)-INTEGER+1):0)
#define TYPENAME(t)	typename[TYPEINDEX(t)]
#define TYPECAST(f,t)	typecast[TYPEINDEX(f)][TYPEINDEX(t)]

#define EXTERNAL(t)	((t)>=F2X)

Exnode_t*
excast(Expr_t* p, register Exnode_t* x, register int type, register Exnode_t* xref, int arg)
{
	register int	t2t;
	char*		s;
	char*		e;

	if (x && x->type != type && type && type != VOID)
	{
		if (!x->type)
		{
			x->type = type;
			return x;
		}
		if (!(t2t = TYPECAST(x->type, type)))
			return x;
		if (EXTERNAL(t2t) && !p->disc->convertf)
			exerror("cannot cast %s to %s", TYPENAME(x->type), TYPENAME(type));
		if (x->op != CONSTANT)
			x = exnewnode(p, t2t, 0, type, x, xref);
		else switch (t2t)
		{
		case F2X:
		case I2X:
		case S2X:
		case X2F:
		case X2I:
		case X2S:
			if (xref && xref->op == ID)
			{
				if ((*p->disc->convertf)(p, x, type, xref->data.variable.symbol, arg, p->disc) < 0)
					exerror("%s: cannot cast constant %s to %s", xref->data.variable.symbol->name, TYPENAME(x->type), TYPENAME(type));
			}
			else if ((*p->disc->convertf)(p, x, type, NiL, arg, p->disc) < 0)
				exerror("cannot cast constant %s to %s", TYPENAME(x->type), TYPENAME(type));
			break;
		case F2I:
			x->data.constant.value.integer = x->data.constant.value.floating;
			break;
		case F2S:
			sfprintf(p->tmp, "%g", x->data.constant.value.floating);
			x->data.constant.value.string = exstash(p->tmp, p->vm);
			break;
		case I2F:
			x->data.constant.value.floating = x->data.constant.value.integer;
			break;
		case I2S:
			sfprintf(p->tmp, "%I*d", sizeof(x->data.constant.value.integer), x->data.constant.value.integer);
			x->data.constant.value.string = exstash(p->tmp, p->vm);
			break;
		case S2F:
			x->data.constant.value.integer = strtod(x->data.constant.value.string, &e);
			if (*e)
				x->data.constant.value.floating = *x->data.constant.value.string != 0;
			break;
		case S2I:
			s = x->data.constant.value.string;
			x->data.constant.value.integer = strtoll(s, &e, 0);
			if (*e)
				x->data.constant.value.integer = *s != 0;
			break;
		default:
			exerror("internal error: %d: unknown cast op", t2t);
			break;
		}
		x->type = type;
	}
	return x;
}

#if 0

/*
 * convert value v from type from to type to
 * string data placed in buf
 */

Extype_t
exconvert(Expr_t* p, Extype_t v, int from, int to, char* buf, size_t size)
{
	register int	t2t;
	int		n;
	Exnode_t	tmp;

	if (from && (t2t = TYPECAST(from, to)))
	{
		if (EXTERNAL(t2t) && !p->disc->convertf)
			exerror("cannot cast %s to %s", TYPENAME(from), TYPENAME(to));
		switch (t2t)
		{
		case F2X:
		case I2X:
		case S2X:
		case X2F:
		case X2I:
		case X2S:
			tmp.type = from;
			tmp.name = "*INTERNAL*";
			tmp.data.constant.value = v;
			if ((*p->disc->convertf)(p, &tmp, to, NiL, -1, p->disc) < 0)
				exerror("cannot convert %s to %s", TYPENAME(from), TYPENAME(to));
			if (t2t == X2S)
			{
				n = strlen(tmp.data.constant.value.string);
				if (n >= size)
					n = size - 1;
				memcpy(buf, tmp.data.constant.value.string, n);
				buf[n] = 0;
				vmfree(p->vm, tmp.data.constant.value.string);
				tmp.data.constant.value.string = buf;
			}
			return tmp.data.constant.value;
		case F2I:
			v.integer = (type == UNSIGNED) ? (Sfulong_t)v.floating : v.floating;
			break;
		case F2S:
			sfsprintf(buf, size, "%g", v.floating);
			v.string = buf;
			break;
		case I2F:
			v.floating = (from == UNSIGNED) ? (Sfulong_t)v.integer : v.integer;
			break;
		case I2S:
			sfsprintf(buf, size, "%I*d", sizeof(v.integer), v.integer);
			v.string = buf;
			break;
		case S2F:
			v.floating = *v.string != 0;
			break;
		case S2I:
			v.integer = *v.string != 0;
			break;
		default:
			exerror("internal error: %d: unknown conversion op", t2t);
			break;
		}
	}
	return v;
}

#endif

/*
 * force ref . sym qualification
 */

static Exid_t*
qualify(register Exref_t* ref, register Exid_t* sym)
{
	register Exid_t*	x;
	char*			s;

	while (ref->next)
		ref = ref->next;
	sfprintf(expr.program->tmp, "%s.%s", ref->symbol->name, sym->name);
	s = exstash(expr.program->tmp, NiL);
	if (!(x = (Exid_t*)dtmatch(expr.program->symbols, s)))
	{
		if (x = newof(0, Exid_t, 1, strlen(s) - EX_NAMELEN + 1))
		{
			memcpy(x, sym, sizeof(Exid_t) - EX_NAMELEN);
			strcpy(x->name, s);
			dtinsert(expr.program->symbols, x);
		}
		else
		{
			exnospace();
			x = sym;
		}
	}
	return x;
}

/*
 * check function call arg types and count
 * return function identifier node
 */

static Exnode_t*
call(Exref_t* ref, register Exid_t* fun, register Exnode_t* args)
{
	register int	t;
	register int	type;
	Exnode_t*	x;
	int		num;

	x = exnewnode(expr.program, ID, 0, 0, NiL, NiL);
	t = fun->type;
	x->data.variable.symbol = fun = QUALIFY(ref, fun);
	x->data.variable.reference = ref;
	num = 0;
	N(t);
	while (type = T(t))
	{
		if (!args)
		{
			exerror("%s: not enough args", fun->name);
			return args;
		}
		num++;
		if (type != args->data.operand.left->type)
			args->data.operand.left = excast(expr.program, args->data.operand.left, type, NiL, num);
		args = args->data.operand.right;
		N(t);
	}
	if (args)
		exerror("%s: too many args", fun->name);
	return x;
}

/*
 * precompile a printf/scanf call
 */

static Print_t*
preprint(register Exnode_t* args)
{
	register Print_t*	x;
	register char*		s;
	register int		c;
	int			t;
	int			i;
	int			n;
	char*			e;
	char*			f;
	Print_t*		p;
	Print_t*		q;

	if (!args || args->data.operand.left->type != STRING)
		exerror("format string argument expected");
	if (args->data.operand.left->op != CONSTANT)
	{
		x = ALLOCATE(expr.program, Print_t);
		memzero(x, sizeof(*x));
		x->arg = args;
		return x;
	}
	f = args->data.operand.left->data.constant.value.string;
	args = args->data.operand.right;
	for (s = f; *s; s++)
	{
		sfputc(expr.program->tmp, *s);
		if (*s == '%')
		{
			if (!*++s)
				exerror("%s: trailing %% in format", f);
			if (*s != '%')
				break;
			if (args)
				sfputc(expr.program->tmp, '%');
		}
	}
	x = 0;
	for (;;)
	{
		q = ALLOCATE(expr.program, Print_t);
		if (x)
			x->next = q;
		else
			p = q;
		x = q;
		memzero(x, sizeof(*x));
		if (*s)
		{
			i = 0;
			t = INTEGER;
			for (;;)
			{
				switch (c = *s++)
				{
				case 0:
					exerror("unterminated %%... in format");
					goto done;
				case '*':
					if (i >= elementsof(x->param))
					{
						*s = 0;
						exerror("format %s has too many * arguments", f);
						goto done;
					}
					if (!args)
					{
						*s = 0;
						exerror("format %s * argument expected", f);
						goto done;
					}
					x->param[i++] = args->data.operand.left;
					args = args->data.operand.right;
					break;
				case '(':
					n = 1;
					for (;;)
					{
						sfputc(expr.program->tmp, c);
						switch (c = *s++)
						{
						case 0:
							s--;
							break;
						case '(':
							n++;
							continue;
						case ')':
							if (--n <= 0)
								break;
							continue;
						default:
							continue;
						}
						break;
					}
					break;
				case 'c':
				case 'd':
					goto specified;
				case 'e':
				case 'f':
				case 'g':
					t = FLOATING;
					goto specified;
				case 'h':
					exerror("short formats not supported");
					goto done;
				case 'l':
					t = INTEGER;
					break;
				case 'o':
				case 'u':
				case 'x':
				case 'T':
					t = UNSIGNED;
					goto specified;
				case 's':
				case 'S':
					t = STRING;
					goto specified;
				case '[':
					n = sfstrtell(expr.program->tmp);
					sfputc(expr.program->tmp, c);
					e = s;
					c = *s++;
					while (c)
					{
						sfputc(expr.program->tmp, c);
						if ((c = *s++) == ']')
						{
							t = STRING;
							goto specified;
						}
					}
					s = e;
					sfstrseek(expr.program->tmp, n, SEEK_SET);
					break;
				default:
					if (isalpha(c))
						goto specified;
					break;
				}
				sfputc(expr.program->tmp, c);
			}
		specified:
			sfputc(expr.program->tmp, c);
			for (e = s; *s; s++)
			{
				if (*s == '%')
				{
					if (!*++s)
					{
						*e = 0;
						exerror("%s: trailing %% in format", f);
						goto done;
					}
					if (*s != '%')
					{
						s--;
						break;
					}
				}
				sfputc(expr.program->tmp, *s);
			}
			if (!args)
			{
				*e = 0;
				exerror("%s format argument expected", f);
				goto done;
			}
			x->arg = args->data.operand.left;
			switch (t)
			{
			case FLOATING:
				if (x->arg->type != FLOATING)
					x->arg = exnewnode(expr.program, x->arg->type == STRING ? S2F : INTEGRAL(x->arg->type) ? I2F : X2F, 0, FLOATING, x->arg, x->arg->op == ID ? x->arg : (Exnode_t*)0);
				break;
			case INTEGER:
			case UNSIGNED:
				if (!INTEGRAL(x->arg->type))
					x->arg = exnewnode(expr.program, x->arg->type == STRING ? S2I : x->arg->type == FLOATING ? F2I : X2I, 0, INTEGER, x->arg, x->arg->op == ID ? x->arg : (Exnode_t*)0);
				x->arg->type = t;
				break;
			case STRING:
				if (x->arg->type != STRING)
				{
					if (x->arg->op == CONSTANT && x->arg->data.constant.reference && expr.program->disc->convertf)
					{
						if ((*expr.program->disc->convertf)(expr.program, x->arg, STRING, x->arg->data.constant.reference, 0, expr.program->disc) < 0)
							exerror("cannot convert string format argument");
						else x->arg->data.constant.value.string = vmstrdup(expr.program->vm, x->arg->data.constant.value.string);
					}
					else if (!expr.program->disc->convertf || x->arg->op != ID && x->arg->op != DYNAMIC && x->arg->op != F2X && x->arg->op != I2X && x->arg->op != S2X)
						exerror("string format argument expected");
					else
						x->arg = exnewnode(expr.program, x->arg->type == FLOATING ? F2S : INTEGRAL(x->arg->type) ? I2S : X2S, 0, STRING, x->arg, x->arg->op == ID ? x->arg : (Exnode_t*)0);
				}
				break;
			}
			args = args->data.operand.right;
		}
		x->format = exstash(expr.program->tmp, expr.program->vm);
		if (!*s)
			break;
		f = s;
	}
	if (args)
		exerror("too many format arguments");
 done:
	sfstrseek(expr.program->tmp, 0, SEEK_SET);
	return p;
}

/*
 * push a new input stream and program
 */

int
expush(Expr_t* p, const char* name, int line, const char* sp, Sfio_t* fp)
{
	register Exinput_t*	in;
	register char*		s;
	char			buf[PATH_MAX];

	if (!(in = newof(0, Exinput_t, 1, 0)))
	{
		exnospace();
		return -1;
	}
	if (!p->input)
		p->input = &expr.null;
	if (!(in->bp = in->sp = (char*)sp))
	{
		if (in->fp = fp)
			in->close = 0;
		else if (name)
		{
			if (!(s = pathfind(name, p->disc->lib, p->disc->type, buf, sizeof(buf))) || !(in->fp = sfopen(NiL, s, "r")))
			{
				exerror("%s: file not found", name);
				in->bp = in->sp = "";
			}
			else
			{
				name = (const char*)vmstrdup(p->vm, s);
				in->close = 1;
			}
		}
	}
	else in->fp = 0;
	if (!(in->next = p->input)->next)
	{
		p->errors = 0;
		if (!(p->disc->flags & EX_INTERACTIVE))
		{
			if (line >= 0)
				error_info.line = line;
		}
		else if (!error_info.line)
			error_info.line = 1;
	}
	else if (line >= 0)
		error_info.line = line;
	setcontext(p);
	p->eof = 0;
	p->input = in;
	in->file = error_info.file;
	if (line >= 0)
		error_info.file = (char*)name;
	in->line = error_info.line;
	in->nesting = 0;
	in->unit = !name && !line;
	p->program = expr.program;
	expr.program = p;
	return 0;
}

/*
 * pop the current input stream
 */

int
expop(register Expr_t* p)
{
	register int		c;
	register Exinput_t*	in;

	if (!(in = p->input) || !in->next || in->unit)
		return -1;
	if (in->nesting)
		exerror("unbalanced quote or nesting construct");
	error_info.file = in->file;
	if (in->next->next)
		error_info.line = in->line;
	else
	{
		if (p->errors && in->fp && p->linep != p->line)
			while ((c = sfgetc(in->fp)) != EOF)
				if (c == '\n')
				{
					error_info.line++;
					break;
				}
		if (!(p->disc->flags & EX_INTERACTIVE))
			error_info.line = in->line;
	}
	if (in->fp && in->close)
		sfclose(in->fp);
	if (in->pushback)
		free(in->pushback);
	p->input = in->next;
	free(in);
	setcontext(p);
	if (p->program)
		expr.program = p->program;
	return 0;
}

/*
 * compile the expression in [sf]p
 */

int
excomp(register Expr_t* p, const char* name, int line, const char* sp, Sfio_t* fp)
{
	Exid_t*	v;
	int	eof;

	p->more = 0;
	eof = p->eof;
	if (!sp && !fp)
	{
		if (!p->input)
			return -1;
	}
	else if (expush(p, name, line, sp, fp))
		return -1;
	else
		p->input->unit = line >= 0;
	exparse();
	p->input->unit = 0;
	expop(p);
	p->eof = eof;
	if (expr.statics)
	{
		for (v = (Exid_t*)dtfirst(p->symbols); v; v = (Exid_t*)dtnext(p->symbols, v))
			if (v->isstatic)
			{
				dtdelete(p->symbols, v);
				if (!--expr.statics)
					break;
			}
		expr.statics = 0;
	}
	return 0;
}

/*
 * free the program p
 */

void
exclose(register Expr_t* p, int all)
{
	register int		i;
	register Exinput_t*	in;

	if (p)
	{
		if (all)
		{
			for (i = 3; i < elementsof(p->file); i++)
				if (p->file[i])
					sfclose(p->file[i]);
			if (p->vm)
				vmclose(p->vm);
			if (p->ve)
				vmclose(p->ve);
			if (p->symbols)
				dtclose(p->symbols);
			if (p->tmp)
				sfclose(p->tmp);
			while (in = p->input)
			{
				if (in->pushback)
					free(in->pushback);
				if (in->fp && in->close)
					sfclose(in->fp);
				if (p->input = in->next)
					free(in);
			}
			free(p);
		}
		else
		{
			vmclear(p->ve);
			p->main.value = 0;
		}
	}
}

#endif