DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:reply-to:to:message-id:subject
	:mime-version:content-type:content-transfer-encoding; q=dns; s=
	default; b=SaV6hFIsCo0u3KpDRrg/TYm1U6gUhZKE6w4WUOhd1uCw+JZL/3Bm6
	4aZW9nzQf7neEwnqYSxK/OfBAFIotujYmIGh5sxuJ9y/pq52IG+YvtEXHtx9os3+
	2FIvX/pEAyUihfhZ8ycjqH4tgJbAH6UV+MYrWTOaUWtVCEIBUnv6gc=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Date: Mon, 27 Apr 2015 22:52:26 +0000 (UTC)
From: "Cary R." <cygcary AT yahoo DOT com>
Reply-To: "Cary R." <cygcary AT yahoo DOT com>
To: The Cygwin Mailing List <cygwin AT cygwin DOT com>
Message-ID: <261055273.5586453.1430175146814.JavaMail.yahoo@mail.yahoo.com>
Subject: Incorrect compile warning, possible bug in inttypes.h
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The following code:

#include <stdio.h>
#include <inttypes.h>

int main()
{
        int32_t ival = 1;
        uint32_t uval = 2;

        printf("int = %"PRId32", uint = %"PRIu32".\n", ival, uval);
        return 0;
}


when compiled with either gcc or clang on a 32-bit system and with the -Wall flag produces the following warnings:

tmp.c: In function ‘main’:
tmp.c:9:5: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘int32_t’ [-Wformat=]
         printf("int = %"PRId32", uint = %"PRIu32".\n", ival, uval);
         ^
tmp.c:9:5: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 3 has type ‘uint32_t’ [-Wformat=]
tmp.c:9:5: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘int32_t’ [-Wformat=]
tmp.c:9:5: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 3 has type ‘uint32_t’ [-Wformat=]

I'm not sure why the double report for this, but both gcc and clang do the same thing. This looks to be an issue that is generated because a long is 32 bits on a 32-bit system and in inttypes.h __have_long32 is likely defined and that is forcing the use of the 'l' formats when that is incorrect for at least these two 32 bit types.

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple