Re: c/7776: const char* p = "foo"; if (p == "foo") ... is compiled without warning!

Re: c/7776: const char* p = "foo"; if (p == "foo") ... is compiled without warning!

[Andrew Pinski]

The following reply was made to PR c/7776; it has been noted by GNATS.

From: Andrew Pinski <pinskia@physics.uc.edu>
To: udbz@rz.uni-karlsruhe.de
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: c/7776: const char* p = "foo"; if (p == "foo") ... is compiled without warning!
Date: Fri, 30 Aug 2002 13:35:21 -0400

 Are you asking for a warning so that the warning would suggest strcmp?
 The code you provide does make sense to check for if the two occurrences
 of "foo" are the same because the C standard does not say if they have
 to be the same.
 
 Thanks,
 Andrew Pinski
 

Re: c/7776: const char* p = "foo"; if (p == "foo") ... is compiled without warning!

[Peter Schlaile]

The following reply was made to PR c/7776; it has been noted by GNATS.

From: Peter Schlaile <udbz@rz.uni-karlsruhe.de>
To: Andrew Pinski <pinskia@physics.uc.edu>
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: c/7776: const char* p = "foo"; if (p == "foo") ... is compiled
 without warning!
Date: Fri, 30 Aug 2002 19:57:40 +0200 (CEST)

 Hi,
 
 On Fri, 30 Aug 2002, Andrew Pinski wrote:
 
 > Are you asking for a warning so that the warning would suggest strcmp?
 
 That was the intended idea, yes!
 
 > The code you provide does make sense to check for if the two occurrences
 > of "foo" are the same because the C standard does not say if they have
 > to be the same.
 
 Yup!
 
 Greetings,
 Peter
 
 ---
 Peter Schlaile  ***  eMail udbz@rz.uni-karlsruhe.de
 
 So Linus, what are we doing tonight?
           The same thing we do every night Tux. Try to take over the world!
 

c/7776: const char* p = "foo"; if (p == "foo") ... is compiled without warning!

[udbz]

>Number:         7776
>Category:       c
>Synopsis:       const char* p = "foo"; if (p == "foo") ... is compiled without warning!
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Fri Aug 30 09:06:00 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     udbz@rz.uni-karlsruhe.de
>Release:        gcc-3.0.3
>Organization:
>Environment:

>Description:
The code construct below IMHO never makes sense and
should spill a warning.

It once caused me two months of work to discover this little
bug in the wine sources.
>How-To-Repeat:
#include <stdlib.h>
#include <stdio.h>

int main(int argc, const char** argv)
{
	const char * p = "Hello";

	if (p == "Hello") {
		fprintf(stderr, "1\n");
	} else {
		fprintf(stderr, "2\n");
	}
	return 0;
}
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: