[src/trunk]: src/usr.bin/xlint/lint1 lint: fix build on Cygwin

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

details:   https://anonhg.NetBSD.org/src/rev/773af55cd2f5
branches:  trunk
changeset: 958882:773af55cd2f5
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Jan 24 09:44:35 2021 +0000

description:
lint: fix build on Cygwin

Cygwin does not conform to C99, which says that MB_CUR_MAX has type
size_t.

Instead, Cygwin defines it as type int.  This leads to compile errors
because comparing signed with unsigned expressions is surprising in C.

diffstat:

 usr.bin/xlint/lint1/lex.c |  16 +++++++++-------
 1 files changed, 9 insertions(+), 7 deletions(-)

diffs (54 lines):

diff -r 6905f7e50167 -r 773af55cd2f5 usr.bin/xlint/lint1/lex.c
--- a/usr.bin/xlint/lint1/lex.c Sun Jan 24 09:25:16 2021 +0000
+++ b/usr.bin/xlint/lint1/lex.c Sun Jan 24 09:44:35 2021 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: lex.c,v 1.6 2021/01/24 09:25:16 rillig Exp $ */
+/* $NetBSD: lex.c,v 1.7 2021/01/24 09:44:35 rillig Exp $ */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou.  All Rights Reserved.
@@ -38,7 +38,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: lex.c,v 1.6 2021/01/24 09:25:16 rillig Exp $");
+__RCSID("$NetBSD: lex.c,v 1.7 2021/01/24 09:44:35 rillig Exp $");
 #endif
 
 #include <ctype.h>
@@ -845,13 +845,15 @@
 lex_wide_character_constant(void)
 {
        static  char buf[MB_LEN_MAX + 1];
-       size_t  i;
+       size_t  i, imax;
        int c;
        wchar_t wc;
 
+       imax = MB_CUR_MAX;
+
        i = 0;
        while ((c = get_escaped_char('\'')) >= 0) {
-               if (i < MB_CUR_MAX)
+               if (i < imax)
                        buf[i] = (char)c;
                i++;
        }
@@ -865,14 +867,14 @@
                /* empty character constant */
                error(73);
        } else {
-               if (i > MB_CUR_MAX) {
-                       i = MB_CUR_MAX;
+               if (i > imax) {
+                       i = imax;
                        /* too many characters in character constant */
                        error(71);
                } else {
                        buf[i] = '\0';
                        (void)mbtowc(NULL, NULL, 0);
-                       if (mbtowc(&wc, buf, MB_CUR_MAX) < 0)
+                       if (mbtowc(&wc, buf, imax) < 0)
                                /* invalid multibyte character */
                                error(291);
                }