522 lines
11 KiB
C
522 lines
11 KiB
C
/*
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* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
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* See the copyright notice in the ACK home directory, in the file "Copyright".
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*/
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/* $Header$ */
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/* A R I T H M E T I C C O N V E R S I O N S */
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/* This file contains the routines for the various conversions that
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may befall operands in C. It is structurally a mess, but I haven't
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decided yet whether I can't find the right structure or the
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semantics of C is a mess.
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*/
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#include <alloc.h>
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#include "lint.h"
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#include "nofloat.h"
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#include "nobitfield.h"
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#include "idf.h"
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#include "arith.h"
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#include "type.h"
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#include "label.h"
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#include "expr.h"
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#include "Lpars.h"
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#include "field.h"
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#include "mes.h"
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#include "noRoption.h"
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extern char *symbol2str();
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extern char options[];
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arithbalance(e1p, oper, e2p) /* RM 6.6 */
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register struct expr **e1p, **e2p;
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int oper;
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{
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/* The expressions *e1p and *e2p are balanced to be operands
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of the arithmetic operator oper.
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*/
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register int t1, t2, u1, u2;
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t1 = any2arith(e1p, oper);
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t2 = any2arith(e2p, oper);
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/* Now t1 and t2 are either INT or LONG or DOUBLE */
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#ifndef NOFLOAT
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if (t1 == DOUBLE) {
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if (t2 != DOUBLE)
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int2float(e2p, double_type);
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return;
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}
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if (t2 == DOUBLE) {
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if (t1 != DOUBLE)
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int2float(e1p, double_type);
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return;
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}
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#endif NOFLOAT
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/* Now they are INT or LONG */
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u1 = (*e1p)->ex_type->tp_unsigned;
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u2 = (*e2p)->ex_type->tp_unsigned;
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/* if either is long, the other will be */
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if (t1 == LONG && t2 != LONG)
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t2 = int2int(e2p, u2 ? ulong_type : long_type);
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else
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if (t2 == LONG && t1 != LONG)
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t1 = int2int(e1p, u1 ? ulong_type : long_type);
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/* if either is unsigned, the other will be */
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if (u1 && !u2)
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t2 = int2int(e2p, (t1 == LONG) ? ulong_type : uint_type);
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else
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if (!u1 && u2)
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t1 = int2int(e1p, (t2 == LONG) ? ulong_type : uint_type);
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}
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relbalance(e1p, oper, e2p)
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register struct expr **e1p, **e2p;
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{
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/* The expressions *e1p and *e2p are balanced to be operands
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of the relational operator oper.
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*/
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if ((*e1p)->ex_type->tp_fund == FUNCTION)
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function2pointer(*e1p);
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if ((*e2p)->ex_type->tp_fund == FUNCTION)
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function2pointer(*e2p);
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if ((*e1p)->ex_type->tp_fund == POINTER)
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ch76pointer(e2p, oper, (*e1p)->ex_type);
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else
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if ((*e2p)->ex_type->tp_fund == POINTER)
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ch76pointer(e1p, oper, (*e2p)->ex_type);
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else
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if ( (*e1p)->ex_type == (*e2p)->ex_type &&
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(*e1p)->ex_type->tp_fund == ENUM
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)
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{}
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else
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arithbalance(e1p, oper, e2p);
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}
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ch76pointer(expp, oper, tp)
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struct expr **expp;
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register struct type *tp;
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{
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/* Checks whether *expp may be compared to tp using oper,
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as described in chapter 7.6 and 7.7.
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tp is known to be a pointer.
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*/
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register struct expr *exp = *expp;
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if (exp->ex_type->tp_fund == POINTER) {
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if (exp->ex_type != tp)
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ch7cast(expp, oper, tp);
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}
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else
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if (is_integral_type(exp->ex_type)) {
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if ( (oper != EQUAL && oper != NOTEQUAL && oper != ':') ||
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(!is_cp_cst(exp) || exp->VL_VALUE != 0)
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) { /* ch 7.6, ch 7.7 */
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expr_warning(exp, "%s on %s and pointer",
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symbol2str(oper),
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symbol2str(exp->ex_type->tp_fund)
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);
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}
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ch7cast(expp, CAST, tp);
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}
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else {
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expr_error(exp, "%s on %s and pointer",
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symbol2str(oper),
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symbol2str(exp->ex_type->tp_fund)
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);
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ch7cast(expp, oper, tp);
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}
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}
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int
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any2arith(expp, oper)
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register struct expr **expp;
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register int oper;
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{
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/* Turns any expression into int_type, long_type or
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double_type.
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*/
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int fund;
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switch (fund = (*expp)->ex_type->tp_fund) {
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case CHAR:
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case SHORT:
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int2int(expp,
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(*expp)->ex_type->tp_unsigned ? uint_type : int_type);
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break;
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case INT:
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case LONG:
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break;
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case ENUM:
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/* test the admissibility of the operator */
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if ( is_test_op(oper) || oper == '=' || oper == PARCOMMA ||
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oper == ',' || oper == ':'
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) {
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/* allowed by K & R */
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}
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else
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#ifndef NOROPTION
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if (!options['R']) {
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/* allowed by us */
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}
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else
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expr_warning(*expp, "%s on enum", symbol2str(oper));
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#endif NOROPTION
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#ifndef LINT
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int2int(expp, int_type);
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#endif LINT
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break;
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#ifndef NOFLOAT
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case FLOAT:
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float2float(expp, double_type);
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break;
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case DOUBLE:
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break;
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#endif NOFLOAT
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#ifndef NOBITFIELD
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case FIELD:
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field2arith(expp);
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break;
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#endif NOBITFIELD
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default:
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expr_error(*expp, "operator %s on non-numerical operand (%s)",
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symbol2str(oper), symbol2str(fund));
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case ERRONEOUS:
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erroneous2int(expp);
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break;
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}
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return (*expp)->ex_type->tp_fund;
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}
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erroneous2int(expp)
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struct expr **expp;
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{
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/* the (erroneous) expression *expp is replaced by an
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int expression
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*/
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register struct expr *exp = *expp;
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int flags = exp->ex_flags;
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free_expression(exp);
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exp = intexpr((arith)0, INT);
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exp->ex_flags = (flags | EX_ERROR);
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*expp = exp;
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}
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struct expr *
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arith2arith(tp, oper, expr)
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struct type *tp;
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int oper;
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register struct expr *expr;
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{
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/* arith2arith constructs a new expression containing a
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run-time conversion between some arithmetic types.
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*/
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register struct expr *new = new_expr();
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new->ex_file = expr->ex_file;
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new->ex_line = expr->ex_line;
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new->ex_type = tp;
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new->ex_class = Type;
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return new_oper(tp, new, oper, expr);
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}
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int
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int2int(expp, tp)
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struct expr **expp;
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register struct type *tp;
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{
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/* The expression *expp, which is of some integral type, is
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converted to the integral type tp.
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*/
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register struct expr *exp = *expp;
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if (is_cp_cst(exp)) {
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register struct type *tp1 = exp->ex_type;
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exp->ex_type = tp;
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if (! tp1->tp_unsigned && tp->tp_unsigned) {
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/* Avoid "unreal" overflow warnings, such as
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caused by f.i.:
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unsigned int x = ~0;
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unsigned int y = -1;
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*/
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extern long full_mask[];
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long remainder = exp->VL_VALUE &
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~full_mask[(int)(tp->tp_size)];
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if (remainder == 0 ||
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remainder == ~full_mask[(int)(tp->tp_size)]) {
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exp->VL_VALUE &= ~remainder;
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}
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}
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cut_size(exp);
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}
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else {
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exp = arith2arith(tp, INT2INT, exp);
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}
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*expp = exp;
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return exp->ex_type->tp_fund;
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}
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#ifndef NOFLOAT
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int2float(expp, tp)
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register struct expr **expp;
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struct type *tp;
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{
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/* The expression *expp, which is of some integral type, is
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converted to the floating type tp.
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*/
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register struct expr *exp = *expp;
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char buf[32];
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fp_used = 1;
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if (is_cp_cst(exp)) {
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*expp = new_expr();
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**expp = *exp;
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sprint(buf+1, "%ld", (long)(exp->VL_VALUE));
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buf[0] = '-';
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exp = *expp;
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exp->ex_type = tp;
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exp->ex_class = Float;
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exp->FL_VALUE = Salloc(buf, (unsigned)strlen(buf)+2) + 1;
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exp->FL_DATLAB = 0;
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}
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else *expp = arith2arith(tp, INT2FLOAT, *expp);
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}
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float2int(expp, tp)
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struct expr **expp;
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struct type *tp;
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{
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/* The expression *expp, which is of some floating type, is
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converted to the integral type tp.
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*/
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fp_used = 1;
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*expp = arith2arith(tp, FLOAT2INT, *expp);
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}
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float2float(expp, tp)
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register struct expr **expp;
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struct type *tp;
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{
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/* The expression *expp, which is of some floating type, is
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converted to the floating type tp.
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There is no need for an explicit conversion operator
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if the expression is a constant.
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*/
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fp_used = 1;
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if (is_fp_cst(*expp))
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(*expp)->ex_type = tp;
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else
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*expp = arith2arith(tp, FLOAT2FLOAT, *expp);
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}
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#endif NOFLOAT
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array2pointer(exp)
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register struct expr *exp;
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{
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/* The expression, which must be an array, is converted
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to a pointer.
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*/
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exp->ex_type = construct_type(POINTER, exp->ex_type->tp_up, (arith)0);
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}
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function2pointer(exp)
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register struct expr *exp;
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{
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/* The expression, which must be a function, is converted
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to a pointer to the function.
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*/
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exp->ex_type = construct_type(POINTER, exp->ex_type, (arith)0);
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}
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string2pointer(ex)
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register struct expr *ex;
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{
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/* The expression, which must be a string constant, is converted
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to a pointer to the string-containing area.
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*/
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label lbl = data_label();
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code_string(ex->SG_VALUE, ex->SG_LEN, lbl);
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ex->ex_class = Value;
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ex->VL_CLASS = Label;
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ex->VL_LBL = lbl;
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ex->VL_VALUE = (arith)0;
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}
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opnd2integral(expp, oper)
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register struct expr **expp;
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int oper;
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{
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register int fund = (*expp)->ex_type->tp_fund;
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if (fund != INT && fund != LONG) {
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expr_error(*expp, "%s operand to %s",
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symbol2str(fund), symbol2str(oper));
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erroneous2int(expp);
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/* fund = INT; */
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}
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}
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opnd2logical(expp, oper)
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register struct expr **expp;
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int oper;
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{
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int fund = (*expp)->ex_type->tp_fund;
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if (fund == FUNCTION || fund == ARRAY) {
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expr_warning(*expp, "%s operand to %s",
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symbol2str(fund),
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symbol2str(oper));
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if (fund == FUNCTION) {
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function2pointer(*expp);
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}
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else array2pointer(*expp);
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}
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#ifndef NOBITFIELD
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else
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if (fund == FIELD)
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field2arith(expp);
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#endif NOBITFIELD
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switch (fund = (*expp)->ex_type->tp_fund) {
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case CHAR:
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case SHORT:
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case INT:
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case LONG:
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case ENUM:
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case POINTER:
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#ifndef NOFLOAT
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case FLOAT:
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case DOUBLE:
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#endif NOFLOAT
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break;
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default:
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expr_error(*expp, "%s operand to %s",
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symbol2str(fund), symbol2str(oper));
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case ERRONEOUS:
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erroneous2int(expp);
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break;
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}
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}
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opnd2test(expp, oper)
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register struct expr **expp;
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{
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opnd2logical(expp, oper);
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if ((*expp)->ex_class == Oper) {
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if (is_test_op((*expp)->OP_OPER)) {
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/* It is already a test */
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return;
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}
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if ((*expp)->OP_OPER == ',') {
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opnd2test(&((*expp)->OP_RIGHT), oper);
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return;
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}
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}
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ch7bin(expp, NOTEQUAL, intexpr((arith)0, INT));
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}
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int
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is_test_op(oper)
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{
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switch (oper) {
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case '<':
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case '>':
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case LESSEQ:
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case GREATEREQ:
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case EQUAL:
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case NOTEQUAL:
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case '!':
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case AND:
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case OR: /* && and || also impose a test */
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return 1;
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default:
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return 0;
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}
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/*NOTREACHED*/
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}
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any2opnd(expp, oper)
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register struct expr **expp;
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{
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if (!*expp)
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return;
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switch ((*expp)->ex_type->tp_fund) { /* RM 7.1 */
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case CHAR:
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case SHORT:
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case ENUM:
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#ifndef NOFLOAT
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case FLOAT:
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#endif NOFLOAT
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any2arith(expp, oper);
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break;
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case ARRAY:
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array2pointer(*expp);
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break;
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case POINTER:
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if ((*expp)->ex_class == String)
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string2pointer(*expp);
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break;
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#ifndef NOBITFIELD
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case FIELD:
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field2arith(expp);
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break;
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#endif NOBITFIELD
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}
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}
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#ifndef NOBITFIELD
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field2arith(expp)
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register struct expr **expp;
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{
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/* The expression to extract the bitfield value from the
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memory word is put in the tree.
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*/
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register struct type *tp = (*expp)->ex_type->tp_up;
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register struct field *fd = (*expp)->ex_type->tp_field;
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register struct type *atype = tp->tp_unsigned ? uword_type : word_type;
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(*expp)->ex_type = atype;
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if (atype->tp_unsigned) { /* don't worry about the sign bit */
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ch7bin(expp, RIGHT, intexpr((arith)fd->fd_shift, INT));
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ch7bin(expp, '&', intexpr(fd->fd_mask, INT));
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}
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else { /* take care of the sign bit: sign extend if needed */
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arith bits_in_type = atype->tp_size * 8;
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ch7bin(expp, LEFT,
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intexpr(bits_in_type - fd->fd_width - fd->fd_shift,
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INT)
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);
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ch7bin(expp, RIGHT, intexpr(bits_in_type - fd->fd_width, INT));
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}
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ch7cast(expp, CAST, tp); /* restore its original type */
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}
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#endif NOBITFIELD
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#ifndef NOFLOAT
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/* switch_sign_fp() negates the given floating constant expression
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The lexical analyser has reserved an extra byte of space in front
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of the string containing the representation of the floating
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constant. This byte contains the '-' character and we have to
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take care of the first byte the fl_value pointer points to.
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*/
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switch_sign_fp(expr)
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register struct expr *expr;
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{
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if (*(expr->FL_VALUE) == '-')
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++(expr->FL_VALUE);
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else
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--(expr->FL_VALUE);
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}
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#endif NOFLOAT
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