[src/trunk]: src/usr.bin/xlint/lint1 lint: push down complexity from typeok t...

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

details:   https://anonhg.NetBSD.org/src/rev/d6e4e6b3661c
branches:  trunk
changeset: 1017801:d6e4e6b3661c
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Jan 09 23:18:19 2021 +0000

description:
lint: push down complexity from typeok to typeok_shr

Contrary to the comment in typeok, the types of the expressions before
promotions and conversions are not needed for SHL, SHLASS and SHRASS.
Move that code over to typeok_shr, the only place where it is actually
used.  This removes another 3 variables from typeok.

diffstat:

 usr.bin/xlint/lint1/tree.c |  39 ++++++++++++++++++---------------------
 1 files changed, 18 insertions(+), 21 deletions(-)

diffs (84 lines):

diff -r 71394873e0c8 -r d6e4e6b3661c usr.bin/xlint/lint1/tree.c
--- a/usr.bin/xlint/lint1/tree.c        Sat Jan 09 23:02:51 2021 +0000
+++ b/usr.bin/xlint/lint1/tree.c        Sat Jan 09 23:18:19 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tree.c,v 1.142 2021/01/09 23:02:51 rillig Exp $        */
+/*     $NetBSD: tree.c,v 1.143 2021/01/09 23:18:19 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 1.142 2021/01/09 23:02:51 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.143 2021/01/09 23:18:19 rillig Exp $");
 #endif
 
 #include <float.h>
@@ -789,11 +789,22 @@
        return true;
 }
 
+static const tnode_t *
+before_promotion_and_balancing(const tnode_t *tn)
+{
+       while (tn->tn_op == CVT && !tn->tn_cast)
+               tn = tn->tn_left;
+       return tn;
+}
+
 static void
-typeok_shr(mod_t *mp,
-          tnode_t *ln, tspec_t lt, tspec_t olt,
-          tspec_t rt, tspec_t ort)
+typeok_shr(mod_t *mp, tnode_t *ln, tspec_t lt, tnode_t *rn, tspec_t rt)
 {
+       tspec_t olt, ort;
+
+       olt = before_promotion_and_balancing(ln)->tn_type->t_tspec;
+       ort = before_promotion_and_balancing(rn)->tn_type->t_tspec;
+
        /* operands have integer types (checked above) */
        if (pflag && !tspec_is_uint(lt)) {
                /*
@@ -1031,9 +1042,8 @@
 typeok(op_t op, int arg, tnode_t *ln, tnode_t *rn)
 {
        mod_t   *mp;
-       tspec_t lt, rt, olt = NOTSPEC, ort = NOTSPEC;
+       tspec_t lt, rt;
        type_t  *ltp, *rtp;
-       tnode_t *tn;
 
        mp = &modtab[op];
 
@@ -1074,19 +1084,6 @@
                }
        }
 
-       if (op == SHL || op == SHR || op == SHLASS || op == SHRASS) {
-               /*
-                * For these operations we need the types before promotion
-                * and balancing.
-                */
-               for (tn=ln; tn->tn_op==CVT && !tn->tn_cast; tn=tn->tn_left)
-                       continue;
-               olt = tn->tn_type->t_tspec;
-               for (tn=rn; tn->tn_op==CVT && !tn->tn_cast; tn=tn->tn_left)
-                       continue;
-               ort = tn->tn_type->t_tspec;
-       }
-
        switch (op) {
        case POINT:
                /*
@@ -1137,7 +1134,7 @@
                        return false;
                break;
        case SHR:
-               typeok_shr(mp, ln, lt, olt, rt, ort);
+               typeok_shr(mp, ln, lt, rn, rt);
                goto shift;
        case SHL:
                typeok_shl(mp, lt, rt);