[fpc-devel] Free Pascal Bug 4387 ( Daten.Write('BRTF',4); writes only the pointer to the string, not the string itself. )

[Benjamin Rosseaux]

Hello,

http://www.freepascal.org/bugs/showrec.php3?ID=4387

why is this not an (compiler codegen compatibility) bug?

Daten('BRTF',4) should  work like in Delphi (with {$MODE DLEPHI}), with
the Delphi compiler Daten('BRTF',4) writes 'BRTF' and not the pointer to
the string.  Try it yourself!

Delphi translates it to an const char array without a length byte on the 
  beginning. And FreePascal not, and this is the bug.

My opinion you should fix this "bug" to keep the Delphi  Mode still more
compatible with Delphi  And set "not an bug" back to "Unfixed" :)

And I've reposted the bug to
http://www.freepascal.org/bugs/showrec.php3?ID=4390

Benjamin Rosseaux

bugs at freepascal.org schrieb:

>The entry concerning the bug you reported (bug 4387) has been modified:
>
>(View this bug at http://www.freepascal.org/bugs/showrec.php3?ID=4387 )
>Bug ID       : 4387
>Title        : Daten.Write('BRTF',4); writes  only the pointer to the string, not the string itself.
>Name         : Benjamin Rosseaux
>Email        : benjamin at 0ok.de
>Category     : Compiler
>Bug type     : Error
>FPC version  : 2.0.0
>OS           : All
>Date added   : 2005-09-27
>Status       : Not a bug
>Date fixed   : 
>Fixer        : Peter
>Fix version  : 
>Description:
>The following code does not write the 'BRTF' string correctly, but instead the pointer to the string:
>
>Folgender Code schreibt den 'BRTF' String nicht korrekt, sondern statt 'BRTF' den Zeiger zur Zeichenkette:
>
>	# Register %eax,%edx released
>
># [13906] Daten.Write('BRTF',4);
>
>	movl	$4,%ecx
>
>	# Register %eax allocated
>
>	movl	$_$ENGINETRACK$_L31021,%eax
>
>	# Register %ebx allocated
>
>	movl	-4(%ebp),%ebx
>
>	# Register %edx allocated
>
>	movl	(%ebx),%edx
>
>	# Register %esi allocated
>
>	movl	92(%edx),%esi
>
>	movl	%eax,%edx
>
>	movl	%ebx,%eax
>
>	call	*%esi
>
>.section .data
>
>	.balign 4
>
>.globl	_$ENGINETRACK$_L31019
>
>_$ENGINETRACK$_L31019:
>
>.globl	_$ENGINETRACK$_L31021
>
>_$ENGINETRACK$_L31021:
>
>	.long	_$ENGINETRACK$_L31020
>
>	.long	-1,4
>
>.globl	_$ENGINETRACK$_L31020
>
>_$ENGINETRACK$_L31020:
>
>	.ascii	"BRTF\000"
>
>
>
>-----
>
>
>
>The following code writes the 'BRTF' correct:
>
>Folgender Code schreibt den 'BRTF' String korrekt:
>
>	# Register %eax,%edx released
>
># [13905] Daten.Write(Sign,4);
>
>	movl	$4,%ecx
>
>	# Register %eax allocated
>
>	movl	$TC_ENGINETRACK_TENGINETRACK_$_SPEICHEREBRT$TENGINESTREAM$$BOOLEAN_SIGN,%eax
>
>	# Register %ebx allocated
>
>	movl	-4(%ebp),%ebx
>
>	# Register %edx allocated
>
>	movl	(%ebx),%edx
>
>	# Register %esi allocated
>
>	movl	92(%edx),%esi
>
>	movl	%eax,%edx
>
>	movl	%ebx,%eax
>
>	call	*%esi
>
>.section .data
>
>	.balign 4
>
># [13897] CONST Sign:ARRAY[1..4] OF CHAR='BRTF';
>
>TC_ENGINETRACK_TENGINETRACK_$_SPEICHEREBRT$TENGINESTREAM$$BOOLEAN_SIGN:
>
>	.byte	66,82,84,70
>
>
>
>-----
>
>
>
>Write is/Write Ist:
>
>FUNCTION TEngineStream.Write(CONST Buf;Count:INTEGER):INTEGER;
>
>
>
>
>
>Comment      :
>The string is an ansistring which is an pointer  that points to some memory location where the data is stored. The typed const is directly the address of the data.
>
>
>
>
>Program:
>
>
>
>  
>