RE: Analysis: "rpl_realloc" & Visual C++ 6.0 function "realloc"

Discussion moved to "Bug CVS", sorry.

> From: Conrad T. Pino
> 
> Hi Derek,
> ================
> I'm looking into subject functions to determine
> what value we're getting by using "rpl_realloc"
> in the Windows build.
> ================
> Conclusion qualified by OS and compiler:
> 
> On Windows 2000 Visual C++ 6.0 the native "realloc"
> conforms to requirements.  The use of "rpl_realloc"
> results in negative impact to the project since
> Windows build has warnings due to lack of function
> prototype.

Conclusion withdrawn, not enough test cases.

VC 6.0 and GNU diverge in "realloc" when (1) memory
pointer != NULL and (2) new size == zero.  In this
case VC 6.0 returns NULL and GNU returns memory.

See below for details:

> -------
> I coded a program to test the native "realloc" for
> the behavior implemented by "rpl_realloc":

But not enough test cases, new program follows:

#include <malloc.h>
#include <stdio.h>

#define FREE(arg) if (arg) free(arg), arg=NULL

int main(int argc, char* argv[])
{
	void *buffer;

	printf("Hello World!\n");

	buffer = realloc( NULL, 0 );
	printf( "case NULL,0: %p\n", buffer );
	FREE( buffer );

	buffer = realloc( NULL, 256 );
	printf( "case NULL,256: %p\n", buffer );
	FREE( buffer );

	buffer = malloc( 256 );
	buffer = realloc( buffer, 0 );
	printf( "case buffer,0: %p\n", buffer );
	FREE( buffer );

	buffer = malloc( 256 );
	buffer = realloc( buffer, 8 );
	printf( "case buffer,8: %p\n", buffer );
	FREE( buffer );

	return 0;
}

> -------
> On NetBSD gcc 2.95.3 the native "realloc" conforms:
> 
> /usr/home/conrad/work:$ gcc -dumpversion
> 2.95.3
> /usr/home/conrad/work:$ gcc VC6test.c
> /usr/home/conrad/work:$ ls -l
> total 16
> -rw-rw-r--  1 conrad  conrad   360 Apr  7 10:43 VC6test.c
> -rwxrwxr-x  1 conrad  conrad  6191 Apr  7 10:43 a.out
> /usr/home/conrad/work:$ ./a.out
> Hello World!
> case NULL,0: 0x805b030
> case NULL,256: 0x805b000
> /usr/home/conrad/work:$ 

/usr/home/conrad/work:$ ./a.out
Hello World!
case NULL,0: 0x805b030
case NULL,256: 0x805b000
case buffer,0: 0x805c030
case buffer,8: 0x805c030
/usr/home/conrad/work:$ 

> -------
> On Windows 2000 VC 6.0 the native "realloc" conforms:
> 
> H:\Conrad\Projects\VC6test\Debug>vc6test
> Hello World!
> case NULL,0: 002F07A8
> case NULL,256: 002F07A8
> 
> H:\Conrad\Projects\VC6test\Debug>

H:\Conrad\Projects\VC6test\Debug>vc6test
Hello World!
case NULL,0: 002F07A8
case NULL,256: 002F07A8
case buffer,0: 00000000
case buffer,8: 002F07A8

H:\Conrad\Projects\VC6test\Debug>
===========
Conrad