[src/trunk]: src/usr.bin/xlint/lint1 lint: clean up merge_qualifiers

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

details:   https://anonhg.NetBSD.org/src/rev/441100340ca3
branches:  trunk
changeset: 982154:441100340ca3
user:      rillig <rillig%NetBSD.org@localhost>
date:      Fri Apr 02 17:01:39 2021 +0000

description:
lint: clean up merge_qualifiers

No functional change.

diffstat:

 usr.bin/xlint/lint1/tree.c |  59 +++++++++++++++++++--------------------------
 1 files changed, 25 insertions(+), 34 deletions(-)

diffs (106 lines):

diff -r 89e3498c90b5 -r 441100340ca3 usr.bin/xlint/lint1/tree.c
--- a/usr.bin/xlint/lint1/tree.c        Fri Apr 02 16:59:59 2021 +0000
+++ b/usr.bin/xlint/lint1/tree.c        Fri Apr 02 17:01:39 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tree.c,v 1.262 2021/04/02 16:38:08 rillig Exp $        */
+/*     $NetBSD: tree.c,v 1.263 2021/04/02 17:01:39 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 1.262 2021/04/02 16:38:08 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.263 2021/04/02 17:01:39 rillig Exp $");
 #endif
 
 #include <float.h>
@@ -67,7 +67,6 @@
                                        const type_t *, tspec_t);
 static void    warn_incompatible_pointers(const mod_t *,
                                           const type_t *, const type_t *);
-static void    merge_qualifiers(type_t **, type_t *, type_t *);
 static bool    has_constant_member(const type_t *);
 static void    check_prototype_conversion(int, tspec_t, tspec_t, type_t *,
                                           tnode_t *);
@@ -2608,31 +2607,30 @@
        }
 }
 
-/*
- * Make sure type (*tpp)->t_subt has at least the qualifiers
- * of tp1->t_subt and tp2->t_subt.
- */
-static void
-merge_qualifiers(type_t **tpp, type_t *tp1, type_t *tp2)
+/* Return a type based on tp1, with added qualifiers from tp2. */
+static type_t *
+merge_qualifiers(type_t *tp1, const type_t *tp2)
 {
-
-       lint_assert((*tpp)->t_tspec == PTR);
+       type_t *ntp, *nstp;
+
        lint_assert(tp1->t_tspec == PTR);
        lint_assert(tp2->t_tspec == PTR);
 
-       if ((*tpp)->t_subt->t_const ==
-           (tp1->t_subt->t_const | tp2->t_subt->t_const) &&
-           (*tpp)->t_subt->t_volatile ==
-           (tp1->t_subt->t_volatile | tp2->t_subt->t_volatile)) {
-               return;
-       }
-
-       *tpp = expr_dup_type(*tpp);
-       (*tpp)->t_subt = expr_dup_type((*tpp)->t_subt);
-       (*tpp)->t_subt->t_const =
-               tp1->t_subt->t_const | tp2->t_subt->t_const;
-       (*tpp)->t_subt->t_volatile =
-               tp1->t_subt->t_volatile | tp2->t_subt->t_volatile;
+       bool c1 = tp1->t_subt->t_const;
+       bool c2 = tp2->t_subt->t_const;
+       bool v1 = tp1->t_subt->t_volatile;
+       bool v2 = tp2->t_subt->t_volatile;
+
+       if (c1 == (c1 | c2) && v2 == (v1 | v2))
+               return tp1;
+
+       nstp = expr_dup_type(tp1->t_subt);
+       nstp->t_const = c1 | c2;
+       nstp->t_volatile = v1 | v2;
+
+       ntp = expr_dup_type(tp1);
+       ntp->t_subt = nstp;
+       return ntp;
 }
 
 /*
@@ -2894,24 +2892,17 @@
                }
                tp = rn->tn_type;
        } else if (lt == PTR && ln->tn_type->t_subt->t_tspec == VOID) {
-               lint_assert(rt == PTR);
-               tp = rn->tn_type;
-               merge_qualifiers(&tp, ln->tn_type, rn->tn_type);
+               tp = merge_qualifiers(rn->tn_type, ln->tn_type);
        } else if (rt == PTR && rn->tn_type->t_subt->t_tspec == VOID) {
-               lint_assert(lt == PTR);
-               tp = ln->tn_type;
-               merge_qualifiers(&tp, ln->tn_type, rn->tn_type);
+               tp = merge_qualifiers(ln->tn_type, rn->tn_type);
        } else {
-               lint_assert(lt == PTR);
-               lint_assert(rt == PTR);
                /*
                 * XXX For now we simply take the left type. This is
                 * probably wrong, if one type contains a function prototype
                 * and the other one, at the same place, only an old style
                 * declaration.
                 */
-               tp = ln->tn_type;
-               merge_qualifiers(&tp, ln->tn_type, rn->tn_type);
+               tp = merge_qualifiers(ln->tn_type, rn->tn_type);
        }
 
        ntn = new_tnode(COLON, tp, ln, rn);