[fpc-pascal] Re: AnsiString (Luis Fernando Del Aguila Mej?a)

Wed Jan 26 14:00:56 CET 2011

Thanks for the tip, David.
My intention is to learn or acquire knowledge.
True the function Length is easier to use, but it's always good to know the 
internals of the compiler.
You never know when something may go wrong.

Thanks

----- Original Message ----- 
From: <fpc-pascal-request at lists.freepascal.org>
To: <fpc-pascal at lists.freepascal.org>
Sent: Wednesday, January 26, 2011 6:00 AM
Subject: fpc-pascal Digest, Vol 79, Issue 46

> Send fpc-pascal mailing list submissions to
> fpc-pascal at lists.freepascal.org
>
> To subscribe or unsubscribe via the World Wide Web, visit
> http://lists.freepascal.org/mailman/listinfo/fpc-pascal
> or, via email, send a message with subject or body 'help' to
> fpc-pascal-request at lists.freepascal.org
>
> You can reach the person managing the list at
> fpc-pascal-owner at lists.freepascal.org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of fpc-pascal digest..."
>
>
> Today's Topics:
>
>   1.  AnsiString (Luis Fernando Del Aguila Mej?a)
>   2. Re:  AnsiString (David Emerson)
>   3. Re:  AnsiString (J?rgen Hestermann)
>   4.  linking error while cross compiling win64 -> Linux64
>      (Julien Devillers)
>   5.  compiling 2.4.2 under 7-64 (Julien Devillers)
>   6. Re:  compiling 2.4.2 under 7-64 (Marco van de Voort)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 25 Jan 2011 10:13:13 -0500
> From: Luis Fernando Del Aguila Mej?a <luis3000 at ec-red.com>
> Subject: [fpc-pascal] AnsiString
> To: <fpc-pascal at lists.freepascal.org>
> Message-ID: <E888C20F4BCF4E559E6F809EC8D9C194 at IntelQuad>
> Content-Type: text/plain; format=flowed; charset="utf-8";
> reply-type=original
>
> The documentation
> (http://www.freepascal.org/docs-html/prog/progsu146.html#x189-1990008.2.7)
> says:
>    -8 Longint current string with size.
>    -4 Longint with reference count.
> But, when I want access to that structure, I have to do it backwards.
>   -8 Longint with reference count.
>   -4 Longint current string with size.
>
> {$codepage UTF8}
> Var
>  cad1:AnsiString;
>  aux1:AnsiString;
>  p:pointer;
> Begin
>
>  SetLength(cad1,8);
>
>  p:=pointer(cad1);
>  Writeln('memory address : ',longint(p));
>  p:=p-4;
>  Write('memory address : ',longint(p),'=');
> //Must show reference count, but shows size
>  Writeln(longint(p^));
>
>  aux1:=cad1;
>
>  p:=pointer(cad1);
>  p:=p-8;
>  Write('memory address : ',longint(p),'=');
> //Must show Size, but shows reference count
>  Writeln(longint(p^));
>
> End.
>
> Do these positions are different, depending on microprocessor being used ?
>
> Thanks
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 25 Jan 2011 11:23:36 -0800
> From: David Emerson <dle3ab at angelbase.com>
> Subject: Re: [fpc-pascal] AnsiString
> To: FPC-Pascal users discussions <fpc-pascal at lists.freepascal.org>
> Message-ID: <201101251123.36365.dle3ab at angelbase.com>
> Content-Type: text/plain;  charset="utf-8"
>
> Luis Fernando Del Aguila Mejía wrote:
>> The documentation
>> (http://www.freepascal.org/docs-html/prog/progsu146.html#x189-1990008.2.7)
>> says:
>>     -8 Longint current string with size.
>>     -4 Longint with reference count.
>>  But, when I want access to that structure, I have to do it backwards.
>>    -8 Longint with reference count.
>>    -4 Longint current string with size.
>
>> Do these positions are different, depending on microprocessor being used 
>> ?
>
> I'm fairly certain that is an error in the documentation, and that it 
> SHOULD
> always be as you discovered it to actually be.
>
>
> As an aside, a tip for doing pointer arithmetic...
>
> var
>  s : ansistring;
>  p : ptruint;
>
> p := pointer(s);
> dec(p);  // equivalent to p:=p-4 because p is a typed pointer.
>
> Using typed pointers in this way will likely make it easier to adapt your 
> code
> to a 64-bit conversion in the future.
>
> Also note that, in this case, dec(p,2) would do p:=p-8, as (hopefully) 
> expected
>
> I use these types of constructs frequently, and it makes it much easier to
> change types, if that is ever necessary, or adapt constructs to new types.
>
> Cheers,
> David
>
>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 26 Jan 2011 07:50:01 +0100
> From: J?rgen Hestermann <juergen.hestermann at gmx.de>
> Subject: Re: [fpc-pascal] AnsiString
> To: FPC-Pascal users discussions <fpc-pascal at lists.freepascal.org>
> Message-ID: <4D3FC419.7070405 at gmx.de>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> Luis Fernando Del Aguila Mejía schrieb:
> >  p:=pointer(cad1);
> >  p:=p-8;
> >  Write('memory address : ',longint(p),'=');   //Must show Size, but
> shows reference count
> >  Writeln(longint(p^));
>
> I fail to see why you need to mess with the internals of ansistrings at 
> all.
> What is the reason to access size and reference count this way?
> At least for the size there is Length(cad1) which would be much clearer.
>
> Although pointer arithmetic is possible in Pascal it looks like C.
> And you loose any help from the compiler to check types.
>
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 25 Jan 2011 17:19:42 +0100
> From: "Julien Devillers" <julien.devillers at opti-time.com>
> Subject: [fpc-pascal] linking error while cross compiling win64 ->
> Linux64
> To: <fpc-pascal at lists.freepascal.org>
> Message-ID:
> <B7A505067065E14189D6C8A52F293CFEB10BF4 at srv-exc.magellan.local>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hi
>
> =
>
>
> I have a linking error with the following compile command :
>
> =
>
>
> =E8 d:\pp\bin\x86_64-win64\fpc 
> lib\snip\snip.dpr -Tlinux -n -va -Mdelphi -F=
> uD:\pp\bin\x86_64-win64/../../units/$FPCTARGET/  =
>
>
> =
>
>
> In the above line, I removed lots of includes. The error is  (founded in 
> th=
> e below log)
>
> =E8 "D:\dev\devtools\MinGW\mingw\bin\ld.exe: unrecognised emulation mode: 
> e=
> lf_x86_64" =
>
>
> =
>
>
> [1.367] Searching file D:\dev\devtools\MinGW\mingw\bin\ld.exe... found
>
> [1.371] Using util D:\dev\devtools\MinGW\mingw\bin\ld.exe
>
> D:\dev\devtools\MinGW\mingw\bin\ld.exe: unrecognised emulation mode: 
> elf_x8=
> 6_64
>
> Supported emulations: i386pe
>
> [1.523] Error while linking
>
> [1.523] There were 1 errors compiling module, stopping
>
> [1.523] Compilation aborted
>
> Error: d:\pp\bin\x86_64-win64\ppcx64.exe returned an error exitcode 
> (normal=
> if you did not specify a source file to be compiled)
>
> =
>
>
> Maybe I don't use the right ld.exe file ?
>
> I'm running fpc 2.4.0
>
> =
>
>
> regards
>
> Julien
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: 
> http://lists.freepascal.org/lists/fpc-pascal/attachments/20110125/5063=
> 8212/attachment.html
>
> ------------------------------
>
> Message: 5
> Date: Tue, 25 Jan 2011 18:11:28 +0100
> From: "Julien Devillers" <julien.devillers at opti-time.com>
> Subject: [fpc-pascal] compiling 2.4.2 under 7-64
> To: <fpc-pascal at lists.freepascal.org>
> Message-ID:
> <B7A505067065E14189D6C8A52F293CFEB10C1F at srv-exc.magellan.local>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hi
>
> =
>
>
> i'm trying to compile fpc 2.4.2 under windows 7 64 bits.
>
> It raises the following error :
>
> =
>
>
> =
>
>
> make[5]: entrant dans le r=E9pertoire =AB C:/FPC/2.4.2/fpc-2.4.2/rtl/win32 
> =
> =BB
>
> c:/gnuwin32/bin/gmkdir.exe -p C:/FPC/2.4.2/fpc-2.4.2/rtl/units/i386-win32
>
> d:/pp_/bin/i386-win32/ppc386.exe -Ur -Xs -O2 -n -Fi../inc -Fi../i386 -Fi../=
> win -FE. -FUC:/FPC/2.4.2/fpc-2.4.2/rtl/units/i386-win32 -di386 -dRELEASE -
>
> s -Sg system.pp -Fi../win
>
> system.pp(1011) Error: Can't create archive file: 
> C:\FPC\2.4.2\fpc-2.4.2\rt=
> l\units\i386-win32\libimpsystem.a
>
> =
>
>
> Instead of making the C:/FPC/2.4.2/fpc-2.4.2/rtl/units/i386-win32, gmkdir 
> c=
> reates a directory named : 
> C:\FPC\2.4.2\fpc-2.4.2\rtl\win32\FPC\2.4.2\fpc=
> -2.4.2\rtl\units\i386-win32
>
> =
>
>
> Should I consider that this is a bug of gmkdir ? I get this file with 
> getGn=
> uWin32.
>
> =
>
>
> regards
>
> Julien
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: 
> http://lists.freepascal.org/lists/fpc-pascal/attachments/20110125/21b2=
> b8c3/attachment-0001.htm
>
> ------------------------------
>
> Message: 6
> Date: Wed, 26 Jan 2011 10:37:56 +0100 (CET)
> From: marcov at stack.nl (Marco van de Voort)
> Subject: Re: [fpc-pascal] compiling 2.4.2 under 7-64
> To: FPC-Pascal users discussions <fpc-pascal at lists.freepascal.org>
> Message-ID: <20110126093756.9C29617598 at turtle.stack.nl>
> Content-Type: text/plain; charset="US-ASCII"
>
> In our previous episode, Julien Devillers said:
>
>> Should I consider that this is a bug of gmkdir ? I get this file with
>> getGnuWin32.
>
> Use the binutils that come with FPC, not the ones from mingw. mingw's
> coreutils package has afaik moved in a different direction since it moved
> from mingw to msys.
>
> That also goes for the linker problem:
>
> ftp://ftp.freepascal.org/pub/fpc/contrib/cross/mingw/win64/
>
> is where the win64 binutils are kept.
>
>
> ------------------------------
>
> _______________________________________________
> fpc-pascal maillist  -  fpc-pascal at lists.freepascal.org
> http://lists.freepascal.org/mailman/listinfo/fpc-pascal
>
> End of fpc-pascal Digest, Vol 79, Issue 46
> ******************************************
> 