c.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

/*@(#)c.c	4.2	Ultrix	11/9/90*/

/************************************************************************
 *									*
 *			Copyright (c) 1986, 1988 by			*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/************************************************************************
 *									*
 *			Modification History				*
 *									*
 *  005 - Fixed erroneous type mismatch.		*
 *		  (Lee Miller, Jan 24, 1990)			*
 *									*
 *	004 - Changed c_typematch to accept 'integer' as well as	*
 *	      'int' because of lk brain damage.				*
 *	      (Jon Reeves, June 9, 1988)				*
 *									*
 *	003 - Merged in 4.3 changes.					*
 *	      (vjh, April 29, 1986)					*
 *									*
 *	002 - Fixed printrange() so that unsigned shorts and chars are	*
 *	      displayed properly.					*
 *	      (vjh, July 8, 1985)					*
 *									*
 *	001 - Modified c_init() to use LanguageName constant in call	*
 *	      to language_define().					*
 *	      (Victoria Holt, June 22, 1985)				*
 *									*
 ************************************************************************/

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#ifndef lint
static char sccsid[] = "@(#)c.c	2.1	ULTRIX	4/24/89";
#endif not lint

/*
 * C-dependent symbol routines.
 */

#include "defs.h"
#include "symbols.h"
#include "printsym.h"
#include "languages.h"
#include "c.h"
#include "tree.h"
#include "eval.h"
#include "operators.h"
#include "mappings.h"
#include "process.h"
#include "runtime.h"
#include "machine.h"
#include "varargs.h"

#ifndef public
# include "tree.h"
#endif

#define isdouble(range) ( \
    range->symvalue.rangev.upper == 0 and range->symvalue.rangev.lower > 0 \
)

#define isrange(t, name) (t->class == RANGE and istypename(t->type, name))

private Language langC;

/*
 * Initialize C language information.
 */

public c_init()
{
    langC = language_define("c", C);
    language_setop(langC, L_PRINTDECL, c_printdecl);
    language_setop(langC, L_PRINTVAL, c_printval);
    language_setop(langC, L_TYPEMATCH, c_typematch);
    language_setop(langC, L_BUILDAREF, c_buildaref);
    language_setop(langC, L_EVALAREF, c_evalaref);
    language_setop(langC, L_MODINIT, c_modinit);
    language_setop(langC, L_HASMODULES, c_hasmodules);
    language_setop(langC, L_PASSADDR, c_passaddr);
    language_setop(langC, L_PRINTF, c_printf);
}

/*
 * Test if two types are compatible.
 */

public Boolean c_typematch(type1, type2)
Symbol type1, type2;
{
    Boolean b;
    register Symbol t1, t2, tmp;

    t1 = type1;
    t2 = type2;
    if (t1 == t2) {
	b = true;
    } else {
	t1 = rtype(t1);
	t2 = rtype(t2);
	if (t1 == t_char->type or t1 == t_int->type or t1 == t_real->type) {
	    tmp = t1;
	    t1 = t2;
	    t2 = tmp;
	}
	b = (Boolean) (
	    (
		isrange(t1, "int") and
		(t2 == t_int->type or t2 == t_char->type)
	    ) or (
		isrange(t1, "char") and
		(t2 == t_char->type or t2 == t_int->type)
	    ) or (
		t1->class == RANGE and isdouble(t1) and t2 == t_real->type
	    ) or (
		t1->class == RANGE and t2->class == RANGE and
		t1->symvalue.rangev.lower == t2->symvalue.rangev.lower and
		t1->symvalue.rangev.upper == t2->symvalue.rangev.upper
	    ) or (
		t1->type == t2->type and (
		    (t1->class == t2->class) or
		    (t1->class == SCAL and t2->class == CONST) or
		    (t1->class == CONST and t2->class == SCAL)
		)
	    ) or (
		t1->class == PTR and c_typematch(t1->type, t_char) and
		t2->class == ARRAY and c_typematch(t2->type, t_char) /*and
		t2->language == primlang     *lrm*/
	    ) or (
		t1->class == ARRAY and c_typematch(t1->type, t_char) and
		t2->class == ARRAY and c_typematch(t2->type, t_char) /*and
		t2->language == primlang     *lrm*/
	    ) or (
		isrange(t1, "integer") and		/* jlr004 */
		(t2 == t_int->type or t2 == t_char->type)
	    )
	);
    }
    return b;
}

/*
 * Print out the declaration of a C variable.
 */

public c_printdecl(s)
Symbol s;
{
    printdecl(s, 0);
}

private printdecl(s, indent)
register Symbol s;
Integer indent;
{
    register Symbol t;
    Boolean semicolon, newline;

    semicolon = true;
    newline = true;
    if (indent > 0) {
	printf("%*c", indent, ' ');
    }
    if (s->class == TYPE) {
	printf("typedef ");
    }
    switch (s->class) {
	case CONST:
	    if (s->type->class == SCAL) {
		printf("enumeration constant with value ");
		eval(s->symvalue.constval);
		c_printval(s);
	    } else {
		printf("const %s = ", symname(s));
		printval(s);
	    }
	    break;

	case TYPE:
	case VAR:
	    if (s->class != TYPE and s->level < 0) {
		printf("register ");
	    }
	    if (s->type->class == ARRAY) {
		printtype(s->type, s->type->type, indent);
		t = rtype(s->type->chain);
		assert(t->class == RANGE);
		printf(" %s[%d]", symname(s), t->symvalue.rangev.upper + 1);
	    } else {
		printtype(s, s->type, indent);
		if (s->type->class != PTR) {
		    printf(" ");
		}
		printf("%s", symname(s));
	    }
	    break;

	case FIELD:
	    if (s->type->class == ARRAY) {
		printtype(s->type, s->type->type, indent);
		t = rtype(s->type->chain);
		assert(t->class == RANGE);
		printf(" %s[%d]", symname(s), t->symvalue.rangev.upper + 1);
	    } else {
		printtype(s, s->type, indent);
		if (s->type->class != PTR) {
		    printf(" ");
		}
		printf("%s", symname(s));
	    }
	    if (isbitfield(s)) {
		printf(" : %d", s->symvalue.field.length);
	    }
	    break;

	case TAG:
	    if (s->type == nil) {
		findtype(s);
		if (s->type == nil) {
		    error("unexpected missing type information");
		}
	    }
	    printtype(s, s->type, indent);
	    break;

	case RANGE:
	case ARRAY:
	case RECORD:
	case VARNT:
	case PTR:
	case FFUNC:
	    semicolon = false;
	    printtype(s, s, indent);
	    break;

	case SCAL:
	    printf("(enumeration constant, value %d)", s->symvalue.iconval);
	    break;

	case PROC:
	    semicolon = false;
	    printf("%s", symname(s));
	    c_listparams(s);
	    newline = false;
	    break;

	case FUNC:
	    semicolon = false;
	    if (not istypename(s->type, "void")) {
		printtype(s, s->type, indent);
		printf(" ");
	    }
	    printf("%s", symname(s));
	    c_listparams(s);
	    newline = false;
	    break;

	case MODULE:
	    semicolon = false;
	    printf("source file \"%s.c\"", symname(s));
	    break;

	case PROG:
	    semicolon = false;
	    printf("executable file \"%s\"", symname(s));
	    break;

	default:
	    printf("[%s]", classname(s));
	    break;
    }
    if (semicolon) {
	putchar(';');
    }
    if (newline) {
	putchar('\n');
    }
}

/*
 * Recursive whiz-bang procedure to print the type portion
 * of a declaration.
 *
 * The symbol associated with the type is passed to allow
 * searching for type names without getting "type blah = blah".
 */

private printtype(s, t, indent)
Symbol s;
Symbol t;
Integer indent;
{
    register Symbol i;
    long r0, r1;
    register String p;

    checkref(s);
    checkref(t);
    switch (t->class) {
	case VAR:
	case CONST:
	case PROC:
	    panic("printtype: class %s", classname(t));
	    break;

	case ARRAY:
	    printf("array[");
	    i = t->chain;
	    if (i != nil) {
		for (;;) {
		    printtype(i, i, indent);
		    i = i->chain;
		    if (i == nil) {
			break;
		    }
		    printf(", ");
		}
	    }
	    printf("] of ");
	    printtype(t, t->type, indent);
	    break;

	case RECORD:
	case VARNT:
	    printf("%s ", c_classname(t));
	    if (s->name != nil and s->class == TAG) {
		p = symname(s);
		if (p[0] == '$' and p[1] == '$') {
		    printf("%s ", &p[2]);
		} else {
		    printf("%s ", p);
		}
	    }
	    printf("{\n", t->class == RECORD ? "struct" : "union");
	    for (i = t->chain; i != nil; i = i->chain) {
		assert(i->class == FIELD);
		printdecl(i, indent+4);
	    }
	    if (indent > 0) {
		printf("%*c", indent, ' ');
	    }
	    printf("}");
	    break;

	case RANGE:
	    r0 = t->symvalue.rangev.lower;
	    r1 = t->symvalue.rangev.upper;
	    if (istypename(t->type, "char")) {
		if (r0 < 0x20 or r0 > 0x7e) {
		    printf("%ld..", r0);
		} else {
		    printf("'%c'..", (char) r0);
		}
		if (r1 < 0x20 or r1 > 0x7e) {
		    printf("\\%lo", r1);
		} else {
		    printf("'%c'", (char) r1);
		}
	    } else if (r0 > 0 and r1 == 0) {
		printf("%ld byte real", r0);
	    } else if (r0 >= 0) {
		printf("%lu..%lu", r0, r1);
	    } else {
		printf("%ld..%ld", r0, r1);
	    }
	    break;

	case PTR: