Re: c/2699: gcc does not warn of dead code

Re: c/2699: gcc does not warn of dead code

[Dara Hazeghi]

The following reply was made to PR c/2699; it has been noted by GNATS.

From: Dara Hazeghi <dhazeghi@yahoo.com>
To: gcc-gnats@gcc.gnu.org
Cc:  
Subject: Re: c/2699: gcc does not warn of dead code
Date: Thu, 8 May 2003 01:28:26 -0700

 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit- 
 trail&database=gcc&pr=2699
 
 Confirmed with mainline 20030507
 
 Dara
 

Re: c/2699: gcc does not warn of dead code

[bangerth]

Synopsis: gcc does not warn of dead code

State-Changed-From-To: open->analyzed
State-Changed-By: bangerth
State-Changed-When: Tue Nov  5 07:45:16 2002
State-Changed-Why:
    Confirmed.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=2699

c/2699: gcc does not warn of dead code

[gpoul]

>Number:         2699
>Category:       c
>Synopsis:       gcc does not warn of dead code
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    unassigned
>State:          open
>Class:          support
>Submitter-Id:   net
>Arrival-Date:   Mon Apr 30 11:56:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     root
>Release:        3.1 20010430 (experimental)
>Organization:
>Environment:
System: Linux ddc 2.2.17 #1 Sun Jun 25 09:24:41 EST 2000 i686 unknown
Architecture: i686

	
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../gcc/configure 
>Description:
	I'm currently reading the book "High Performance Computing" by ora
	and it has some interesting content about compiler optimization.

	In an exercise on p99 it asks the question "Does your compile
	give you a warning"?  Then below this is a demo program with some
	code that can't be reached and I tried this with gcc and I wanted
	to notify you that gcc does not warn (at least not with -Wall)
	about dead code written by the user.

	As I already stated about I built it with gcc -Wall.  I have also
	included the source of the program I used to test this.

	I think this might be a helpful feature but I don't really know if
	it's not already in there or if it isn't even possible.  Therefore
	I chose to file this report as support instead of change-request.
>How-To-Repeat:
	just compile the following source with gcc and it will not give
	you a compiler warning. - there is nothing more to repeat this :)

#include <stdio.h>

int main ()
{
  int k=1;
  int v=0;
  if (k == 0)
    printf("This statement is never executed.\n");

  return 0;
}

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