pexpr.c

把pascal程序转成C语言程序 把pascal程序转成C语言程序

/* "p2c", a Pascal to C translator.
   Copyright (C) 1989, 1990, 1991, 1992, 1993 Free Software Foundation.
   Author's address: [e-mail].

This program 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 (any 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; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */



#define PROTO_PEXPR_C
#include "trans.h"




Expr *dots_n_hats(ex, target)
Expr *ex;
Type *target;
{
    Expr *ex2, *ex3;
    Type *tp, *tp2;
    Meaning *mp, *tvar;
    int hassl;

    for (;;) {
	if ((ex->val.type->kind == TK_PROCPTR ||
	     ex->val.type->kind == TK_CPROCPTR) &&
	    curtok != TOK_ASSIGN &&
	    ((mp = (tp2 = ex->val.type)->basetype->fbase) == NULL ||
	     (mp->isreturn && mp->xnext == NULL) ||
	     curtok == TOK_LPAR) &&
	    (tp2->basetype->basetype != tp_void || target == tp_void) &&
	    (!target || (target->kind != TK_PROCPTR &&
			 target->kind != TK_CPROCPTR))) {
	    hassl = tp2->escale;
	    ex2 = ex;
	    ex3 = copyexpr(ex2);
	    if (hassl != 0)
		ex3 = makeexpr_cast(makeexpr_dotq(ex3, "proc", tp_anyptr),
				    makepointertype(tp2->basetype));
	    ex = makeexpr_un(EK_SPCALL, tp2->basetype->basetype, ex3);
	    if (mp && mp->isreturn) {  /* pointer to buffer for return value */
		tvar = makestmttempvar(ex->val.type->basetype,
				       (ex->val.type->basetype->kind == TK_STRING) ? name_STRING : name_TEMP);
		insertarg(&ex, 1, makeexpr_addr(makeexpr_var(tvar)));
		mp = mp->xnext;
	    }
	    if (mp) {
		if (wneedtok(TOK_LPAR)) {
		    ex = p_funcarglist(ex, mp, 0, 0);
		    skipcloseparen();
		}
	    } else if (curtok == TOK_LPAR) {
		gettok();
		if (!wneedtok(TOK_RPAR))
		    skippasttoken(TOK_RPAR);
	    }
	    if (hassl != 1 || hasstaticlinks == 2) {
		freeexpr(ex2);
	    } else {
		ex2 = makeexpr_dotq(ex2, "link", tp_anyptr),
		ex3 = copyexpr(ex);
		insertarg(&ex3, ex3->nargs, copyexpr(ex2));
		tp = maketype(TK_FUNCTION);
		tp->basetype = tp2->basetype->basetype;
		tp->fbase = tp2->basetype->fbase;
		tp->issigned = 1;
		ex3->args[0]->val.type = makepointertype(tp);
		ex = makeexpr_cond(makeexpr_rel(EK_NE, ex2, makeexpr_nil()),
				   ex3, ex);
	    }
	    if (tp2->basetype->fbase &&
		tp2->basetype->fbase->isreturn &&
		tp2->basetype->fbase->kind == MK_VARPARAM)
		ex = makeexpr_hat(ex, 0);    /* returns pointer to structured result */
	    continue;
	} else if (ex->val.type->kind == TK_FUNCTION &&
		   ex->val.type->meaning &&
		   ex->val.type->meaning->kind == MK_FUNCTION &&
		   ex->val.type->meaning->rectype) {
	    if (curtok == TOK_LPAR || !target ||
		(target->kind != TK_PROCPTR &&
		 target->kind != TK_CPROCPTR)) {
		ex = p_memcall(ex, ex->val.type->meaning);
		continue;
	    } else {
		ex = makeexpr_addrf(ex);
		ex->val.type = tp_cproc;
		note("Pointer to member function may need to be fixed [343]");
		continue;
	    }
	}
        switch (curtok) {

            case TOK_HAT:
	    case TOK_ADDR:
                gettok();
                ex = makeexpr_hat(ex, 1);
                break;

            case TOK_LBR:
                do {
                    gettok();
		    ex2 = p_ord_expr();
		    ex = p_index(ex, ex2);
                } while (curtok == TOK_COMMA);
                if (!wneedtok(TOK_RBR))
		    skippasttotoken(TOK_RBR, TOK_SEMI);
                break;

            case TOK_DOT:
                gettok();
                if (!wexpecttok(TOK_IDENT))
		    break;
		if (ex->val.type->kind == TK_STRING) {
		    if (!strcicmp(curtokbuf, "LENGTH")) {
			ex = makeexpr_bicall_1("strlen", tp_int, ex);
		    } else if (!strcicmp(curtokbuf, "BODY")) {
			/* nothing to do */
		    }
		    gettok();
		    break;
		}
		tp = ex->val.type;
		if (tp->kind == TK_POINTER &&
		    tp->basetype->kind == TK_RECORD &&
		    tp->basetype->issigned) {
		    ex = makeexpr_hat(ex, 0);
		    tp = tp->basetype;
		}
		while (tp) {
		    mp = curtoksym->fbase;
		    while (mp && mp->rectype != tp)
			mp = mp->snext;
		    if (mp)
			break;
		    tp = tp->basetype;
		}
                if (tp)
                    ex = makeexpr_dot(ex, mp);
                else {
                    warning(format_s("No field called %s in that record [288]", curtokbuf));
		    ex = makeexpr_dotq(ex, curtokcase, tp_integer);
		}
                gettok();
                break;

	    case TOK_COLONCOLON:
		gettok();
		if (wexpecttok(TOK_IDENT)) {
		    ex = pascaltypecast(curtokmeaning->type, ex);
		    gettok();
		}
		break;

            default:
                return ex;
        }
    }
}


Expr *p_index(ex, ex2)
Expr *ex, *ex2;
{
    Expr *ex3;
    Type *tp, *ot;
    Meaning *mp;
    int bits;

    tp = ex->val.type;
    if (tp->kind == TK_STRING) {
	if (checkconst(ex2, 0))   /* is it "s[0]"? */
	    return makeexpr_bicall_1("strlen", tp_char, ex);
	else
	    return makeexpr_index(ex, ex2, makeexpr_long(1));
    } else if (tp->kind == TK_ARRAY ||
	       tp->kind == TK_SMALLARRAY) {
	if (tp->smax) {
	    ord_range_expr(tp->indextype, &ex3, NULL);
	    if (ex3->kind == EK_VAR)
		var_reference((Meaning *)ex3->val.i);
	    ex2 = makeexpr_minus(ex2, copyexpr(ex3));
	    if (!nodependencies(ex2, 0) &&
		*getbitsname == '*') {
		mp = makestmttempvar(tp_integer, name_TEMP);
		ex3 = makeexpr_assign(makeexpr_var(mp), ex2);
		ex2 = makeexpr_var(mp);
	    } else
		ex3 = NULL;
	    ex = makeexpr_bicall_3(getbitsname, tp_int,
				   ex, ex2,
				   makeexpr_long(tp->escale));
	    if (tp->kind == TK_ARRAY) {
		if (tp->basetype == tp_sshort)
		    bits = 4;
		else
		    bits = 3;
		insertarg(&ex, 3, makeexpr_long(bits));
	    }
	    ex = makeexpr_comma(ex3, ex);
	    ot = ord_type(tp->smax->val.type);
	    if (ot->kind == TK_ENUM && ot->meaning && useenum)
		ex = makeexpr_cast(ex, tp->smax->val.type);
	    ex->val.type = tp->smax->val.type;
	    return ex;
	} else {
	    ord_range_expr(ex->val.type->indextype, &ex3, NULL);
	    if (ex3->kind == EK_VAR)
		var_reference((Meaning *)ex3->val.i);
	    if (debug>2) { fprintf(outf, "ord_range_expr returns "); dumpexpr(ex3); fprintf(outf, "\n"); }
	    return makeexpr_index(ex, ex2, copyexpr(ex3));
	}
    } else {
	warning("Index on a non-array variable [287]");
	return makeexpr_bin(EK_INDEX, tp_integer, ex, ex2);
    }
}


Expr *fake_dots_n_hats(ex)
Expr *ex;
{
    for (;;) {
        switch (curtok) {

            case TOK_HAT:
	    case TOK_ADDR:
	        if (ex->val.type->kind == TK_POINTER)
		    ex = makeexpr_hat(ex, 0);
		else {
		    ex->val.type = makepointertype(ex->val.type);
		    ex = makeexpr_un(EK_HAT, ex->val.type->basetype, ex);
		}
                gettok();
                break;

            case TOK_LBR:
                do {
                    gettok();
                    ex = makeexpr_bin(EK_INDEX, tp_integer, ex, p_expr(tp_integer));
                } while (curtok == TOK_COMMA);
                if (!wneedtok(TOK_RBR))
		    skippasttotoken(TOK_RBR, TOK_SEMI);
                break;

            case TOK_DOT:
                gettok();
                if (!wexpecttok(TOK_IDENT))
		    break;
                ex = makeexpr_dotq(ex, curtokcase, tp_integer);
                gettok();
                break;

	    case TOK_COLONCOLON:
		gettok();
		if (wexpecttok(TOK_IDENT)) {
		    ex = pascaltypecast(curtokmeaning->type, ex);
		    gettok();
		}
		break;

            default:
                return ex;
        }
    }
}



Static void bindnames(ex)
Expr *ex;
{
    int i;
    Symbol *sp;
    Meaning *mp;

    if (ex->kind == EK_NAME) {
	sp = findsymbol_opt(fixpascalname(ex->val.s));
	if (sp) {
	    mp = sp->mbase;
	    while (mp && !mp->isactive)
		mp = mp->snext;
	    if (mp && !strcmp(mp->name, ex->val.s)) {
		ex->kind = EK_VAR;
		ex->val.i = (long)mp;
		ex->val.type = mp->type;
	    }
	}
    }
    i = ex->nargs;
    while (--i >= 0)
	bindnames(ex->args[i]);
}



void var_reference(mp)
Meaning *mp;
{
    Meaning *mp2;

    mp->refcount++;
    if (mp->ctx && mp->ctx->kind == MK_FUNCTION &&
	mp->ctx->needvarstruct &&
	(mp->kind == MK_VAR ||
	 mp->kind == MK_VARREF ||
	 mp->kind == MK_VARMAC ||
	 mp->kind == MK_PARAM ||
	 mp->kind == MK_VARPARAM ||
	 (mp->kind == MK_CONST &&
	  (mp->type->kind == TK_ARRAY ||
	   mp->type->kind == TK_RECORD)))) {
        if (debug>1) { fprintf(outf, "varstruct'ing %s\n", mp->name); }
        if (!mp->varstructflag) {
            mp->varstructflag = 1;
            if (mp->constdefn &&      /* move init code into function body */
		mp->kind != MK_VARMAC) {
                mp2 = addmeaningafter(mp, curtoksym, MK_VAR);
                curtoksym->mbase = mp2->snext;  /* hide this fake variable */
                mp2->snext = mp;      /* remember true variable */
                mp2->type = mp->type;
                mp2->constdefn = mp->constdefn;
                mp2->isforward = 1;   /* declare it "static" */
                mp2->refcount++;      /* so it won't be purged! */
                mp->constdefn = NULL;
                mp->isforward = 0;
            }
        }
        for (mp2 = curctx->ctx; mp2 != mp->ctx; mp2 = mp2->ctx)
            mp2->varstructflag = 1;
        mp2->varstructflag = 1;
    }
}


Expr *expr_reference(ex)
Expr *ex;
{
    int i;

    for (i = 0; i < ex->nargs; i++)
        expr_reference(ex->args[i]);
    if (ex->kind == EK_VAR)
	var_reference((Meaning *)ex->val.i);
    return ex;
}



Expr *p_variable(target)
Type *target;
{
    Expr *ex, *ex2;
    Meaning *mp;
    Symbol *sym;

    if (curtok != TOK_IDENT) {
        warning("Expected a variable [289]");
	return makeexpr_long(0);
    }
    if (!curtokmeaning) {
	sym = curtoksym;
        ex = makeexpr_name(curtokcase, tp_integer);
        gettok();
        if (curtok == TOK_LPAR) {
            ex = makeexpr_bicall_0(ex->val.s, tp_integer);
            do {
                gettok();
                insertarg(&ex, ex->nargs, p_expr(NULL));
            } while (curtok == TOK_COMMA || curtok == TOK_ASSIGN);
            if (!wneedtok(TOK_RPAR))
		skippasttotoken(TOK_RPAR, TOK_SEMI);
        }
	if (!tryfuncmacro(&ex, NULL))
	    undefsym(sym);
        return fake_dots_n_hats(ex);
    }
    var_reference(curtokmeaning);
    mp = curtokmeaning;
    if (curtokint >= 0  /*mp->kind == MK_FIELD*/) {
	if (withexprs[curtokint])
	    ex = makeexpr_dot(copyexpr(withexprs[curtokint]), mp);
	else
	    ex = makeexpr_name(mp->name, mp->type);
    } else if (mp->kind == MK_CONST &&
	       mp->type->kind == TK_SET &&
	       mp->constdefn) {
	ex = copyexpr(mp->constdefn);
	mp = makestmttempvar(ex->val.type, name_SET);
        ex2 = makeexpr(EK_MACARG, 0);
        ex2->val.type = ex->val.type;
	ex = replaceexprexpr(ex, ex2, makeexpr_var(mp), 0);
        freeexpr(ex2);
    } else if (mp->kind == MK_CONST &&
               (mp == mp_false ||
                mp == mp_true ||
                mp->anyvarflag ||
                (foldconsts > 0 &&
                 (mp->type->kind == TK_INTEGER ||
                  mp->type->kind == TK_BOOLEAN ||
                  mp->type->kind == TK_CHAR ||
                  mp->type->kind == TK_ENUM ||
                  mp->type->kind == TK_SUBR ||
                  mp->type->kind == TK_REAL)) ||
                (foldstrconsts > 0 &&
                 (mp->type->kind == TK_STRING)))) {
        if (mp->constdefn) {
            ex = copyexpr(mp->constdefn);
            if (ex->val.type == tp_int)   /* kludge! */
                ex->val.type = tp_integer;
        } else
            ex = makeexpr_val(copyvalue(mp->val));
    } else if (mp->kind == MK_VARPARAM ||
               mp->kind == MK_VARREF) {
        ex = makeexpr_hat(makeexpr_var(mp), 0);
    } else if (mp->kind == MK_VARMAC) {
        ex = copyexpr(mp->constdefn);
	bindnames(ex);
        ex = gentle_cast(ex, mp->type);
        ex->val.type = mp->type;
    } else if (mp->kind == MK_SPVAR && mp->handler) {
        gettok();
        ex = (*mp->handler)(mp);
        return dots_n_hats(ex, target);
    } else if (mp->kind == MK_VAR ||
               mp->kind == MK_CONST ||
               mp->kind == MK_PARAM) {