usr/src/old/dbx/pascal.c

/*
 * 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[] = "@(#)pascal.c    5.1 (Berkeley) %G%";
#endif not lint

static char rcsid[] = "$Header: pascal.c,v 1.5 84/12/26 10:41:18 linton Exp $";

/*
 * Pascal-dependent symbol routines.
 */

#include "defs.h"
#include "symbols.h"
#include "pascal.h"
#include "languages.h"
#include "tree.h"
#include "eval.h"
#include "mappings.h"
#include "process.h"
#include "runtime.h"
#include "machine.h"

#ifndef public
#endif

private Language pasc;
private boolean initialized;

/*
 * Initialize Pascal information.
 */

public pascal_init()
{
    pasc = language_define("pascal", ".p");
    language_setop(pasc, L_PRINTDECL, pascal_printdecl);
    language_setop(pasc, L_PRINTVAL, pascal_printval);
    language_setop(pasc, L_TYPEMATCH, pascal_typematch);
    language_setop(pasc, L_BUILDAREF, pascal_buildaref);
    language_setop(pasc, L_EVALAREF, pascal_evalaref);
    language_setop(pasc, L_MODINIT, pascal_modinit);
    language_setop(pasc, L_HASMODULES, pascal_hasmodules);
    language_setop(pasc, L_PASSADDR, pascal_passaddr);
    initialized = false;
}

/*
 * Typematch tests if two types are compatible.  The issue
 * is a bit complicated, so several subfunctions are used for
 * various kinds of compatibility.
 */

private boolean builtinmatch (t1, t2)
register Symbol t1, t2;
{
    boolean b;

    b = (boolean) (
        (
            t2 == t_int->type and
            t1->class == RANGE and istypename(t1->type, "integer")
        ) or (
            t2 == t_char->type and
            t1->class == RANGE and istypename(t1->type, "char")
        ) or (
            t2 == t_real->type and
            t1->class == RANGE and istypename(t1->type, "real")
        ) or (
            t2 == t_boolean->type and
            t1->class == RANGE and istypename(t1->type, "boolean")
        )
    );
    return b;
}

private boolean rangematch (t1, t2)
register Symbol t1, t2;
{
    boolean b;
    register Symbol rt1, rt2;

    if (t1->class == RANGE and t2->class == RANGE) {
        rt1 = rtype(t1->type);
        rt2 = rtype(t2->type);
        b = (boolean) (rt1->type == rt2->type);
    } else {
        b = false;
    }
    return b;
}

private boolean nilMatch (t1, t2)
register Symbol t1, t2;
{
    boolean b;

    b = (boolean) (
        (t1 == t_nil and t2->class == PTR) or
        (t1->class == PTR and t2 == t_nil)
    );
    return b;
}

private boolean enumMatch (t1, t2)
register Symbol t1, t2;
{
    boolean b;

    b = (boolean) (
        (t1->class == SCAL and t2->class == CONST and t2->type == t1) or
        (t1->class == CONST and t2->class == SCAL and t1->type == t2)
    );
    return b;
}

private boolean isConstString (t)
register Symbol t;
{
    boolean b;

    b = (boolean) (
        t->language == primlang and t->class == ARRAY and t->type == t_char
    );
    return b;
}

private boolean stringArrayMatch (t1, t2)
register Symbol t1, t2;
{
    boolean b;

    b = (boolean) (
        (
            isConstString(t1) and
            t2->class == ARRAY and compatible(t2->type, t_char->type)
        ) or (
            isConstString(t2) and
            t1->class == ARRAY and compatible(t1->type, t_char->type)
        )
    );
    return b;
}

public boolean pascal_typematch (type1, type2)
Symbol type1, type2;
{
    boolean b;
    Symbol t1, t2, tmp;

    t1 = rtype(type1);
    t2 = rtype(type2);
    if (t1 == t2) {
        b = true;
    } else {
        if (t1 == t_char->type or t1 == t_int->type or
            t1 == t_real->type or t1 == t_boolean->type
        ) {
            tmp = t1;
            t1 = t2;
            t2 = tmp;
        }
        b = (Boolean) (
            builtinmatch(t1, t2) or rangematch(t1, t2) or
            nilMatch(t1, t2) or enumMatch(t1, t2) or
            stringArrayMatch(t1, t2)
        );
    }
    return b;
}

/*
 * Indent n spaces.
 */

private indent (n)
int n;
{
    if (n > 0) {
        printf("%*c", n, ' ');
    }
}

public pascal_printdecl (s)
Symbol s;
{
    register Symbol t;
    Boolean semicolon;

    semicolon = true;
    if (s->class == TYPEREF) {
        resolveRef(t);
    }
    switch (s->class) {
        case CONST:
            if (s->type->class == SCAL) {
                semicolon = false;
                printf("enum constant, ord ");
                eval(s->symvalue.constval);
                pascal_printval(s);
            } else {
                printf("const %s = ", symname(s));
                eval(s->symvalue.constval);
                pascal_printval(s);
            }
            break;

        case TYPE:
            printf("type %s = ", symname(s));
            printtype(s, s->type, 0);
            break;

        case TYPEREF:
            printf("type %s", symname(s));
            break;

        case VAR:
            if (isparam(s)) {
                printf("(parameter) %s : ", symname(s));
            } else {
                printf("var %s : ", symname(s));
            }
            printtype(s, s->type, 0);
            break;

        case REF:
            printf("(var parameter) %s : ", symname(s));
            printtype(s, s->type, 0);
            break;

        case RANGE:
        case ARRAY:
        case RECORD:
        case VARNT:
        case PTR:
        case FILET:
            printtype(s, s, 0);
            semicolon = false;
            break;

        case FVAR:
            printf("(function variable) %s : ", symname(s));
            printtype(s, s->type, 0);
            break;

        case FIELD:
            printf("(field) %s : ", symname(s));
            printtype(s, s->type, 0);
            break;

        case PROC:
            printf("procedure %s", symname(s));
            listparams(s);
            break;

        case PROG:
            printf("program %s", symname(s));
            listparams(s);
            break;

        case FUNC:
            printf("function %s", symname(s));
            listparams(s);
            printf(" : ");
            printtype(s, s->type, 0);
            break;

        case MODULE:
            printf("module %s", symname(s));
            break;

          /*
           * the parameter list of the following should be printed
           * eventually
           */
        case  FPROC:
            printf("procedure %s()", symname(s));
            break;

        case FFUNC:
            printf("function %s()", symname(s));
            break;

        default:
            printf("%s : (class %s)", symname(s), classname(s));
            break;
    }
    if (semicolon) {
        putchar(';');
    }
    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, n)
Symbol s;
Symbol t;
int n;
{
    register Symbol tmp;

    if (t->class == TYPEREF) {
        resolveRef(t);
    }
    switch (t->class) {
        case VAR:
        case CONST:
        case FUNC:
        case PROC:
            panic("printtype: class %s", classname(t));
            break;

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

        case RECORD:
            printRecordDecl(t, n);
            break;

        case FIELD:
            if (t->chain != nil) {
                printtype(t->chain, t->chain, n);
            }
            printf("\t%s : ", symname(t));
            printtype(t, t->type, n);
            printf(";\n");
            break;

        case RANGE:
            printRangeDecl(t);
            break;

        case PTR:
            printf("^");
            printtype(t, t->type, n);
            break;

        case TYPE:
            if (t->name != nil and ident(t->name)[0] != '\0') {
                printname(stdout, t);
            } else {
                printtype(t, t->type, n);
            }
            break;

        case SCAL:
            printEnumDecl(t, n);
            break;

        case SET:
            printf("set of ");
            printtype(t, t->type, n);
            break;

        case FILET:
            printf("file of ");
            printtype(t, t->type, n);
            break;

        case TYPEREF:
            break;

        case FPROC:
            printf("procedure");
            break;

        case FFUNC:
            printf("function");
            break;

        default:
            printf("(class %d)", t->class);
            break;
    }
}

/*
 * Print out a record declaration.
 */

private printRecordDecl (t, n)
Symbol t;
int n;
{
    register Symbol f;

    if (t->chain == nil) {
        printf("record end");
    } else {
        printf("record\n");
        for (f = t->chain; f != nil; f = f->chain) {
            indent(n+4);
            printf("%s : ", symname(f));
            printtype(f->type, f->type, n+4);
            printf(";\n");
        }
        indent(n);
        printf("end");
    }
}

/*
 * Print out the declaration of a range type.
 */

private printRangeDecl (t)
Symbol t;
{
    long r0, r1;

    r0 = t->symvalue.rangev.lower;
    r1 = t->symvalue.rangev.upper;
    if (t == t_char or istypename(t, "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);
    }
}

/*
 * Print out an enumeration declaration.
 */

private printEnumDecl (e, n)
Symbol e;
int n;
{
    Symbol t;

    printf("(");
    t = e->chain;
    if (t != nil) {
        printf("%s", symname(t));
        t = t->chain;
        while (t != nil) {
            printf(", %s", symname(t));
            t = t->chain;
        }
    }
    printf(")");
}

/*
 * List the parameters of a procedure or function.
 * No attempt is made to combine like types.
 */

private listparams(s)
Symbol s;
{
    Symbol t;

    if (s->chain != nil) {
        putchar('(');
        for (t = s->chain; t != nil; t = t->chain) {
            switch (t->class) {
                case REF:
                    printf("var ");
                    break;

                case VAR:
                    break;

                default:
                    panic("unexpected class %d for parameter", t->class);
            }
            printf("%s : ", symname(t));
            printtype(t, t->type);
            if (t->chain != nil) {
                printf("; ");
            }
        }
        putchar(')');
    }
}

/*
 * Print out the value on the top of the expression stack
 * in the format for the type of the given symbol.
 */

public pascal_printval (s)
Symbol s;
{
    prval(s, size(s));
}

private prval (s, n)
Symbol s;
integer n;
{
    Symbol t;
    Address a;
    integer len;
    double r;
    integer i;

    if (s->class == TYPEREF) {
        resolveRef(s);
    }
    switch (s->class) {
        case CONST:
        case TYPE:
        case REF:
        case VAR:
        case FVAR:
        case TAG:
            prval(s->type, n);
            break;

        case FIELD:
                prval(s->type, n);
            break;

        case ARRAY:
            t = rtype(s->type);
            if (t == t_char->type or
                (t->class == RANGE and istypename(t->type, "char"))
            ) {
                len = size(s);
                sp -= len;
                printf("'%.*s'", len, sp);
                break;
            } else {
                printarray(s);
            }
            break;

        case RECORD:
            printrecord(s);
            break;

        case VARNT:
            printf("[variant]");
            break;

        case RANGE:
            printrange(s, n);
            break;

        case FILET:
            a = pop(Address);
            if (a == 0) {
                printf("nil");
            } else {
                printf("0x%x", a);
            }
            break;

        case PTR:
            a = pop(Address);
            if (a == 0) {
                printf("nil");
            } else {
                printf("0x%x", a);
            }
            break;

        case SCAL:
            i = 0;
            popn(n, &i);
            if (s->symvalue.iconval < 256) {
                i &= 0xff;
            } else if (s->symvalue.iconval < 65536) {
                i &= 0xffff;
            }
            printEnum(i, s);
            break;

        case FPROC:
        case FFUNC:
            a = pop(long);
            t = whatblock(a);
            if (t == nil) {
                printf("(proc 0x%x)", a);
            } else {
                printf("%s", symname(t));
            }
            break;

        case SET:
            printSet(s);
            break;

        default:
            if (ord(s->class) < ord(BADUSE) or ord(s->class) > ord(TYPEREF)) {
                panic("printval: bad class %d", ord(s->class));
            }
            printf("[%s]", classname(s));
            break;
    }
}

/*
 * Print out the value of a scalar (non-enumeration) type.
 */

private printrange (s, n)
Symbol s;
integer n;
{
    double d;
    float f;
    integer i;

    if (s->symvalue.rangev.upper == 0 and s->symvalue.rangev.lower > 0) {
        if (n == sizeof(float)) {
            popn(n, &f);
            d = f;
        } else {
            popn(n, &d);
        }
        prtreal(d);
    } else {
        i = 0;
        popn(n, &i);
        printRangeVal(i, s);
    }
}

/*
 * Print out a set.
 */

private printSet (s)
Symbol s;
{
    Symbol t;
    integer nbytes;

    nbytes = size(s);
    t = rtype(s->type);
    printf("[");
    sp -= nbytes;
    if (t->class == SCAL) {
        printSetOfEnum(t);
    } else if (t->class == RANGE) {
        printSetOfRange(t);
    } else {
        error("internal error: expected range or enumerated base type for set");
    }
    printf("]");
}

/*
 * Print out a set of an enumeration.
 */

private printSetOfEnum (t)
Symbol t;
{
    register Symbol e;
    register integer i, j, *p;
    boolean first;

    p = (int *) sp;
    i = *p;
    j = 0;
    e = t->chain;
    first = true;
    while (e != nil) {
        if ((i&1) == 1) {
            if (first) {
                first = false;
                printf("%s", symname(e));
            } else {
                printf(", %s", symname(e));
            }
        }
        i >>= 1;
        ++j;
        if (j >= sizeof(integer)*BITSPERBYTE) {
            j = 0;
            ++p;
            i = *p;
        }
        e = e->chain;
    }
}

/*
 * Print out a set of a subrange type.
 */

private printSetOfRange (t)
Symbol t;
{
    register integer i, j, *p;
    long v;
    boolean first;

    p = (int *) sp;
    i = *p;
    j = 0;
    v = t->symvalue.rangev.lower;
    first = true;
    while (v <= t->symvalue.rangev.upper) {
        if ((i&1) == 1) {
            if (first) {
                first = false;
                printf("%ld", v);
            } else {
                printf(", %ld", v);
            }
        }
        i >>= 1;
        ++j;
        if (j >= sizeof(integer)*BITSPERBYTE) {
            j = 0;
            ++p;
            i = *p;
        }
        ++v;
    }
}

/*
 * Construct a node for subscripting.
 */

public Node pascal_buildaref (a, slist)
Node a, slist;
{
    register Symbol t;
    register Node p;
    Symbol etype, atype, eltype;
    Node esub, r;

    t = rtype(a->nodetype);
    if (t->class != ARRAY) {
        beginerrmsg();
        prtree(stderr, a);
        fprintf(stderr, " is not an array");
        enderrmsg();
    } else {
        r = a;
        eltype = t->type;
        p = slist;
        t = t->chain;
        for (; p != nil and t != nil; p = p->value.arg[1], t = t->chain) {
            esub = p->value.arg[0];
            etype = rtype(esub->nodetype);
            atype = rtype(t);
            if (not compatible(atype, etype)) {
                beginerrmsg();
                fprintf(stderr, "subscript ");
                prtree(stderr, esub);
                fprintf(stderr, " is the wrong type");
                enderrmsg();
            }
            r = build(O_INDEX, r, esub);
            r->nodetype = eltype;
        }
        if (p != nil or t != nil) {
            beginerrmsg();
            if (p != nil) {
                fprintf(stderr, "too many subscripts for ");
            } else {
                fprintf(stderr, "not enough subscripts for ");
            }
            prtree(stderr, a);
            enderrmsg();
        }
    }
    return r;
}

/*
 * Evaluate a subscript index.
 */

public pascal_evalaref (s, base, i)
Symbol s;
Address base;
long i;
{
    Symbol t;
    long lb, ub;

    t = rtype(s);
    s = rtype(t->chain);
    findbounds(s, &lb, &ub);
    if (i < lb or i > ub) {
        error("subscript %d out of range [%d..%d]", i, lb, ub);
    }
    push(long, base + (i - lb) * size(t->type));
}

/*
 * Initial Pascal type information.
 */

#define NTYPES 4

private Symbol inittype[NTYPES + 1];

private addType (n, s, lower, upper)
integer n;
String s;
long lower, upper;
{
    register Symbol t;

    if (n > NTYPES) {
        panic("initial Pascal type number too large for '%s'", s);
    }
    t = insert(identname(s, true));
    t->language = pasc;
    t->class = TYPE;
    t->type = newSymbol(nil, 0, RANGE, t, nil);
    t->type->symvalue.rangev.lower = lower;
    t->type->symvalue.rangev.upper = upper;
    t->type->language = pasc;
    inittype[n] = t;
}

private initTypes ()
{
    addType(1, "boolean", 0L, 1L);
    addType(2, "char", 0L, 255L);
    addType(3, "integer", 0x80000000L, 0x7fffffffL);
    addType(4, "real", 8L, 0L);
    initialized = true;
}

/*
 * Initialize typetable.
 */

public pascal_modinit (typetable)
Symbol typetable[];
{
    register integer i;

    if (not initialized) {
        initTypes();
        initialized = true;
    }
    for (i = 1; i <= NTYPES; i++) {
        typetable[i] = inittype[i];
    }
}

public boolean pascal_hasmodules ()
{
    return false;
}

public boolean pascal_passaddr (param, exprtype)
Symbol param, exprtype;
{
    return false;
}