[src/trunk]: src/usr.bin/xlint/lint1 lint: move pointer subtypes from typeok ...

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/de178b265540
branches:  trunk
changeset: 949337:de178b265540
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Jan 09 23:02:51 2021 +0000

description:
lint: move pointer subtypes from typeok to the sub-functions

The code in typeok is already complicated enough.  Only few of the
checks actually examine the subtype of the pointer, the others don't
need to look at it.  Therefore don't initialize the variables lstp
(left-hand side subtype) and rstp unless they are actually needed.

This reduces the number of variables in typeok and the number of
parameters to the sub-functions.

diffstat:

 usr.bin/xlint/lint1/tree.c |  51 +++++++++++++++++++++++++--------------------
 1 files changed, 28 insertions(+), 23 deletions(-)

diffs (141 lines):

diff -r e740c825c351 -r de178b265540 usr.bin/xlint/lint1/tree.c
--- a/usr.bin/xlint/lint1/tree.c        Sat Jan 09 22:55:36 2021 +0000
+++ b/usr.bin/xlint/lint1/tree.c        Sat Jan 09 23:02:51 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tree.c,v 1.141 2021/01/09 19:13:17 rillig Exp $        */
+/*     $NetBSD: tree.c,v 1.142 2021/01/09 23:02:51 rillig Exp $        */
 
 /*
  * Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: tree.c,v 1.141 2021/01/09 19:13:17 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.142 2021/01/09 23:02:51 rillig Exp $");
 #endif
 
 #include <float.h>
@@ -770,7 +770,7 @@
 }
 
 static bool
-typeok_minus(op_t op, tspec_t lt, type_t *lstp, tspec_t rt, type_t *rstp)
+typeok_minus(op_t op, type_t *ltp, tspec_t lt, type_t *rtp, tspec_t rt)
 {
        /* operands have scalar types (checked above) */
        if (lt == PTR && (!tspec_is_int(rt) && rt != PTR)) {
@@ -781,7 +781,7 @@
                return false;
        }
        if (lt == PTR && rt == PTR) {
-               if (!eqtype(lstp, rstp, 1, 0, NULL)) {
+               if (!eqtype(ltp->t_subt, rtp->t_subt, 1, 0, NULL)) {
                        /* illegal pointer subtraction */
                        error(116);
                }
@@ -873,15 +873,14 @@
 }
 
 static bool
-typeok_eq(tnode_t *ln, tspec_t lt, tspec_t lst,
-         tnode_t *rn, tspec_t rt, tspec_t rst)
+typeok_eq(tnode_t *ln, tspec_t lt, tnode_t *rn, tspec_t rt)
 {
-       if (lt == PTR && ((rt == PTR && rst == VOID) ||
+       if (lt == PTR && ((rt == PTR && rn->tn_type->t_tspec == VOID) ||
                          tspec_is_int(rt))) {
                if (rn->tn_op == CON && rn->tn_val->v_quad == 0)
                        return true;
        }
-       if (rt == PTR && ((lt == PTR && lst == VOID) ||
+       if (rt == PTR && ((lt == PTR && ln->tn_type->t_tspec == VOID) ||
                          tspec_is_int(lt))) {
                if (ln->tn_op == CON && ln->tn_val->v_quad == 0)
                        return true;
@@ -929,9 +928,12 @@
 
 static bool
 typeok_colon(mod_t *mp,
-            tnode_t *ln, type_t *ltp, tspec_t lt, type_t *lstp, tspec_t lst,
-            tnode_t *rn, type_t *rtp, tspec_t rt, type_t *rstp, tspec_t rst)
+            tnode_t *ln, type_t *ltp, tspec_t lt,
+            tnode_t *rn, type_t *rtp, tspec_t rt)
 {
+       type_t *lstp, *rstp;
+       tspec_t lst, rst;
+
        if (tspec_is_arith(lt) && tspec_is_arith(rt))
                return true;
 
@@ -940,6 +942,11 @@
        if (lt == UNION && rt == UNION && ltp->t_str == rtp->t_str)
                return true;
 
+       lstp = lt == PTR ? ltp->t_subt : NULL;
+       rstp = rt == PTR ? rtp->t_subt : NULL;
+       lst = lstp != NULL ? lstp->t_tspec : NOTSPEC;
+       rst = rstp != NULL ? rstp->t_tspec : NOTSPEC;
+
        /* combination of any pointer and 0, 0L or (void *)0 is ok */
        if (lt == PTR && ((rt == PTR && rst == VOID) || tspec_is_int(rt))) {
                if (rn->tn_op == CON && rn->tn_val->v_quad == 0)
@@ -1024,21 +1031,21 @@
 typeok(op_t op, int arg, tnode_t *ln, tnode_t *rn)
 {
        mod_t   *mp;
-       tspec_t lt, rt = NOTSPEC, lst = NOTSPEC, rst = NOTSPEC, olt = NOTSPEC,
-           ort = NOTSPEC;
-       type_t  *ltp, *rtp = NULL, *lstp = NULL, *rstp = NULL;
+       tspec_t lt, rt, olt = NOTSPEC, ort = NOTSPEC;
+       type_t  *ltp, *rtp;
        tnode_t *tn;
 
        mp = &modtab[op];
 
        lint_assert((ltp = ln->tn_type) != NULL);
-
-       if ((lt = ltp->t_tspec) == PTR)
-               lst = (lstp = ltp->t_subt)->t_tspec;
+       lt = ltp->t_tspec;
+
        if (mp->m_binary) {
                lint_assert((rtp = rn->tn_type) != NULL);
-               if ((rt = rtp->t_tspec) == PTR)
-                       rst = (rstp = rtp->t_subt)->t_tspec;
+               rt = rtp->t_tspec;
+       } else {
+               rtp = NULL;
+               rt = NOTSPEC;
        }
 
        if (mp->m_requires_integer) {
@@ -1126,7 +1133,7 @@
                        return false;
                break;
        case MINUS:
-               if (!typeok_minus(op, lt, lstp, rt, rstp))
+               if (!typeok_minus(op, ltp, lt, rtp, rt))
                        return false;
                break;
        case SHR:
@@ -1143,7 +1150,7 @@
                 * Accept some things which are allowed with EQ and NE,
                 * but not with ordered comparisons.
                 */
-               if (typeok_eq(ln, lt, lst, rn, rt, rst))
+               if (typeok_eq(ln, lt, rn, rt))
                        break;
                /* FALLTHROUGH */
        case LT:
@@ -1159,9 +1166,7 @@
                        return false;
                break;
        case COLON:
-               if (!typeok_colon(mp,
-                   ln, ltp, lt, lstp, lst,
-                   rn, rtp, rt, rstp, rst))
+               if (!typeok_colon(mp, ln, ltp, lt, rn, rtp, rt))
                        return false;
                break;
        case ASSIGN: