#32797 [Opn]: Compile fails with xml_element.c: my_free using gcc 4

From: Date: Fri, 22 Apr 2005 07:14:42 +0000
Subject: #32797 [Opn]: Compile fails with xml_element.c: my_free using gcc 4
References: 1  Groups: php.bugs 
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 ID:               32797
 Updated by:       sniper@php.net
 Reported By:      JClawson at tamu dot edu
 Status:           Open
 Bug Type:         Compile Failure
 Operating System: * (with GCC 4 only)
 PHP Version:      5.0.4
 New Comment:

Not everyone will use GCC..ever.



Previous Comments:
------------------------------------------------------------------------

[2005-04-22 08:14:33] JClawson at tamu dot edu

Hmmm... I thought free was supposed to ignore the null pointer.  At
least that was my understanding:

Here is a nice table:
http://developer.apple.com/qa/qa2001/qa1259.html

I guess its better to be safe than sorry.

------------------------------------------------------------------------

[2005-04-22 07:24:46] abies@php.net

1) Relying on free() to ignore NULL pointers is not portable: we do
have to support other compilers beside GCC 4

2) Using cast expressions as lvalues has always been supported in C,
but apparently GCC 4 suddenly doesn't support it anymore. In this
particular case, however, we might change the macro so it only does the
cast for the argument to free() , and only for compilers that require
it, i.e. compilers/libc's that define free like free(char*)


------------------------------------------------------------------------

[2005-04-22 04:44:12] wez@php.net

Please lose the attitude; we don't have time for that.
As for PHP; you appear to have the knowledge--submit a working patch
that doesn't break the code.

------------------------------------------------------------------------

[2005-04-22 04:10:00] JClawson at tamu dot edu

Oh... Everyone will not be using GCC 3 forever.  Don't you think it
would be prudent to correct obvious errors now?

After all if you have the following code:

if((char*)root->name)
{
   free((char*)root->name);
   (char*)root->name = 0;

}

why would you assign a pointer to 0?

And for whatever reason... why the stupid if statement????
Why not just simplify everything with:

free((char*)root->name);

Bam... correct C code.  If root->name is NULL thats ok... because free
can take NULL as a paramater!

You don't free somthing and then try to assign an integer to it...
seriously.

------------------------------------------------------------------------

[2005-04-22 03:59:04] JClawson at tamu dot edu

Sorry... the code I posted should be this

if (root->name) {
             free((char *)root->name);
             root->name = NULL;
      }

------------------------------------------------------------------------

The remainder of the comments for this report are too long. To view
the rest of the comments, please view the bug report online at
    http://bugs.php.net/32797

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