[src/trunk]: src/usr.bin/xlint/lint1 lint: extract duplicate code into is_nul...

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

details:   https://anonhg.NetBSD.org/src/rev/750bcf5a7b6e
branches:  trunk
changeset: 980114:750bcf5a7b6e
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Jan 24 11:34:01 2021 +0000

description:
lint: extract duplicate code into is_null_pointer

No functional change.

diffstat:

 usr.bin/xlint/lint1/tree.c |  61 +++++++++++++++++++++------------------------
 1 files changed, 28 insertions(+), 33 deletions(-)

diffs (117 lines):

diff -r 2d3abba95358 -r 750bcf5a7b6e usr.bin/xlint/lint1/tree.c
--- a/usr.bin/xlint/lint1/tree.c        Sun Jan 24 11:31:47 2021 +0000
+++ b/usr.bin/xlint/lint1/tree.c        Sun Jan 24 11:34:01 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tree.c,v 1.189 2021/01/24 11:21:58 rillig Exp $        */
+/*     $NetBSD: tree.c,v 1.190 2021/01/24 11:34:01 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 1.189 2021/01/24 11:21:58 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.190 2021/01/24 11:34:01 rillig Exp $");
 #endif
 
 #include <float.h>
@@ -722,6 +722,16 @@
        return tn;
 }
 
+static bool
+is_null_pointer(const tnode_t *tn)
+{
+       tspec_t t = tn->tn_type->t_tspec;
+
+       return ((t == PTR && tn->tn_type->t_subt->t_tspec == VOID) ||
+               is_integer(t))
+              && (tn->tn_op == CON && tn->tn_val->v_quad == 0);
+}
+
 /*
  * See if the node is valid as operand of an operator that compares its
  * argument with 0.
@@ -952,16 +962,10 @@
 static bool
 is_typeok_eq(const tnode_t *ln, tspec_t lt, const tnode_t *rn, tspec_t rt)
 {
-       if (lt == PTR && ((rt == PTR && rn->tn_type->t_subt->t_tspec == VOID) ||
-                         is_integer(rt))) {
-               if (rn->tn_op == CON && rn->tn_val->v_quad == 0)
-                       return true;
-       }
-       if (rt == PTR && ((lt == PTR && ln->tn_type->t_subt->t_tspec == VOID) ||
-                         is_integer(lt))) {
-               if (ln->tn_op == CON && ln->tn_val->v_quad == 0)
-                       return true;
-       }
+       if (lt == PTR && is_null_pointer(rn))
+               return true;
+       if (rt == PTR && is_null_pointer(ln))
+               return true;
        return false;
 }
 
@@ -1027,15 +1031,11 @@
        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) || is_integer(rt))) {
-               if (rn->tn_op == CON && rn->tn_val->v_quad == 0)
-                       return true;
-       }
-       if (rt == PTR && ((lt == PTR && lst == VOID) || is_integer(lt))) {
-               if (ln->tn_op == CON && ln->tn_val->v_quad == 0)
-                       return true;
-       }
+       /* combination of any pointer and null pointer is ok */
+       if (lt == PTR && is_null_pointer(rn))
+               return true;
+       if (rt == PTR && is_null_pointer(ln))
+               return true;
 
        if ((lt == PTR && is_integer(rt)) || (is_integer(lt) && rt == PTR)) {
                const char *lx = lt == PTR ?  "pointer" : "integer";
@@ -1559,11 +1559,9 @@
                /* both are struct or union */
                return ltp->t_str == rtp->t_str;
 
-       /* 0, 0L and (void *)0 may be assigned to any pointer */
-       if (lt == PTR && ((rt == PTR && rst == VOID) || is_integer(rt))) {
-               if (rn->tn_op == CON && rn->tn_val->v_quad == 0)
-                       return true;
-       }
+       /* a null pointer may be assigned to any pointer */
+       if (lt == PTR && is_null_pointer(rn))
+               return true;
 
        if (lt == PTR && rt == PTR && (lst == VOID || rst == VOID)) {
                /* two pointers, at least one pointer to void */
@@ -2030,20 +2028,17 @@
 convert(op_t op, int arg, type_t *tp, tnode_t *tn)
 {
        tnode_t *ntn;
-       tspec_t nt, ot, ost = NOTSPEC;
+       tspec_t nt, ot;
 
        nt = tp->t_tspec;
-       if ((ot = tn->tn_type->t_tspec) == PTR)
-               ost = tn->tn_type->t_subt->t_tspec;
+       ot = tn->tn_type->t_tspec;
 
        if (!tflag && !sflag && op == FARG)
                check_prototype_conversion(arg, nt, ot, tp, tn);
        if (is_integer(nt) && is_integer(ot)) {
                check_integer_conversion(op, arg, nt, ot, tp, tn);
-       } else if (nt == PTR && ((ot == PTR && ost == VOID) ||
-                                is_integer(ot)) && tn->tn_op == CON &&
-                  tn->tn_val->v_quad == 0) {
-               /* 0, 0L and (void *)0 may be assigned to any pointer. */
+       } else if (nt == PTR && is_null_pointer(tn)) {
+               /* a null pointer may be assigned to any pointer. */
        } else if (is_integer(nt) && nt != BOOL && ot == PTR) {
                check_pointer_integer_conversion(op, nt, tp, tn);
        } else if (nt == PTR && ot == PTR) {