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