__stdcall alternative

**Ian Collins** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

Bartc wrote:

I'm mixing C and ASM, and for calling ASM from C, I just happened to use the
__stdcall convention (using C convention is not practical for other
reasons).
>

What is __stdcall? It's not C, so it must be platform specific, try a
group for your platform, you'll get more help there.

--
Ian Collins.

**jacob navia** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

Bartc wrote:

I'm mixing C and ASM, and for calling ASM from C, I just happened to use the
__stdcall convention (using C convention is not practical for other
reasons).
>
But, __stdcall seems to assume that machine registers are saved by the
called routine (as far as I can gather after a few hours messing with some
strange behaviours especially with optimised C code).
>

OBVIOUSLY you should save the registers ytour compiler thinks are permanent

Under windows (where stdcall is commonly used) you should save
(I am assuming 64 bit CPU)

rsi
rdi
rbx
r12-r15
rbp

And at the end you should issue a
ret $8

when you receive 8 bytes of arguments for instance.

Is there any other call convention I can use likely to be commonly
available?
>

you could just as well use the C calling convention. The registers to save
are THE SAME but you should just issue

ret
and the called procedure adjusts the stack.

Or is there a way of specifying that an external function does not save
registers or is badly behaved?
>

There is NO way to do that. YOU HAVE TO SAVE THOSE if not
you will just have a crash.

>

--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique

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**jacob navia** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

Ian Collins wrote:

Bartc wrote:

>I'm mixing C and ASM, and for calling ASM from C, I just happened to use the
>__stdcall convention (using C convention is not practical for other
>reasons).
>>

What is __stdcall?

What's the point of showing your ignorance as it was a quality?

You do not know the subject matter?

Just stay silent! Is that too complicated?

It's not C,

Of course it is. It is a common extension.

so it must be platform specific,

no, it isn't

--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique

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**Antoninus Twink** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

On 24 Apr 2008 at 20:56, jacob navia wrote:

Bartc wrote:

>Or is there a way of specifying that an external function does not save
>registers or is badly behaved?
>>

>
There is NO way to do that. YOU HAVE TO SAVE THOSE if not
you will just have a crash.

It sounded to me like the external function isn't one he's written, and
he can't control its behavior. If that's the case, there's nothing for
it except to work out what calling convention the function expects, and
use that.

**Eric Sosman** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

jacob navia wrote:

Ian Collins wrote:

>Bartc wrote:

>>I'm mixing C and ASM, and for calling ASM from C, I just happened to
>>use the __stdcall convention (using C convention is not practical for
>>other reasons).
>>>

>What is __stdcall?

>
What's the point of showing your ignorance as it was a quality?
>
You do not know the subject matter?
>
Just stay silent! Is that too complicated?
>
>

>It's not C,

>
Of course it is. It is a common extension.
>

>so it must be platform specific,

>
no, it isn't

Oh, good! Then I'll start using it right away!

% cat foo.c
extern void __stdcall foo(void);
% cc foo.c
"foo.c", line 1: syntax error before or at: foo
"foo.c", line 1: warning: old-style declaration or incorrect type for: foo
cc: acomp failed for foo.c
%

Hmmm -- Something seems to be amiss. I'll try a
different machine and a different compiler:

>gcc foo.c

foo.c:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before
'foo'

What am I doing wrong? You've said __stdcall isn't
platform-specific, but I've tried two platforms and it doesn't
work on either of them!

--
Eric.Sosman@sun .com

**Keith Thompson** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

jacob navia <jacob@nospam.c omwrites:

Ian Collins wrote:

>Bartc wrote:

>>I'm mixing C and ASM, and for calling ASM from C, I just happened
>>to use the __stdcall convention (using C convention is not
>>practical for other reasons).
>>>

>What is __stdcall?

>
What's the point of showing your ignorance as it was a quality?
>
You do not know the subject matter?
>
Just stay silent! Is that too complicated?
>
>

>It's not C,

>
Of course it is. It is a common extension.
>

>so it must be platform specific,

>
no, it isn't

"_stdcall" isn't platform-specific? Seriously?

--
Keith Thompson (The_Other_Keit h) <kst-u@mib.org>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

**jacob navia** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

Eric Sosman wrote:

jacob navia wrote:

>Ian Collins wrote:

>>Bartc wrote:
>>>I'm mixing C and ASM, and for calling ASM from C, I just happened to
>>>use the __stdcall convention (using C convention is not practical
>>>for other reasons).
>>>>
>>What is __stdcall?

>>
>What's the point of showing your ignorance as it was a quality?
>>
>You do not know the subject matter?
>>
>Just stay silent! Is that too complicated?
>>
>>

>>It's not C,

>>
>Of course it is. It is a common extension.
>>

>>so it must be platform specific,

>>
>no, it isn't

>
Oh, good! Then I'll start using it right away!
>
% cat foo.c
extern void __stdcall foo(void);
% cc foo.c
"foo.c", line 1: syntax error before or at: foo
"foo.c", line 1: warning: old-style declaration or incorrect type for: foo
cc: acomp failed for foo.c
%
>
Hmmm -- Something seems to be amiss. I'll try a
different machine and a different compiler:
>

>gcc foo.c

foo.c:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before
'foo'
>
What am I doing wrong? You've said __stdcall isn't
platform-specific, but I've tried two platforms and it doesn't
work on either of them!
>

If you use gcc you should
#ifndef STDCALL
#define STDCALL __attribute__(( stdcall))
#endif

>What's the point of showing your ignorance as it was a quality?
>>
>You do not know the subject matter?
>>
>Just stay silent! Is that too complicated?

--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique

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**jacob navia** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

Keith Thompson wrote:

jacob navia <jacob@nospam.c omwrites:

>Ian Collins wrote:

>>Bartc wrote:
>>>I'm mixing C and ASM, and for calling ASM from C, I just happened
>>>to use the __stdcall convention (using C convention is not
>>>practical for other reasons).
>>>>
>>What is __stdcall?

>What's the point of showing your ignorance as it was a quality?
>>
>You do not know the subject matter?
>>
>Just stay silent! Is that too complicated?
>>
>>

>>It's not C,

>Of course it is. It is a common extension.
>>

>>so it must be platform specific,

>no, it isn't

>
"_stdcall" isn't platform-specific? Seriously?
>

#ifndef STDCALL
#define STDCALL __attribute__(( stdcall))
#endif

--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique

403 Forbidden

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**Eric Sosman** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

jacob navia wrote:

Eric Sosman wrote:

>jacob navia wrote:

>>Ian Collins wrote:
>>>Bartc wrote:
>>>>I'm mixing C and ASM, and for calling ASM from C, I just happened
>>>>to use the __stdcall convention (using C convention is not
>>>>practical for other reasons).
>>>>>
>>>What is __stdcall?
>>>
>>What's the point of showing your ignorance as it was a quality?
>>>
>>You do not know the subject matter?
>>>
>>Just stay silent! Is that too complicated?
>>>
>>>
>>>It's not C,
>>>
>>Of course it is. It is a common extension.
>>>
>>>so it must be platform specific,
>>>
>>no, it isn't

>>
> Oh, good! Then I'll start using it right away!
>>
>% cat foo.c
>extern void __stdcall foo(void);
>% cc foo.c
>"foo.c", line 1: syntax error before or at: foo
>"foo.c", line 1: warning: old-style declaration or incorrect type for:
>foo
>cc: acomp failed for foo.c
>%
>>
> Hmmm -- Something seems to be amiss. I'll try a
>different machine and a different compiler:
>>

> >gcc foo.c

>foo.c:1: error: expected '=', ',', ';', 'asm' or '__attribute__'
>before 'foo'
>>
> What am I doing wrong? You've said __stdcall isn't
>platform-specific, but I've tried two platforms and it doesn't
>work on either of them!
>>

>
If you use gcc you should
#ifndef STDCALL
#define STDCALL __attribute__(( stdcall))
#endif

... but you said __stdcall wasn't platform-specific, so
why do I have to write __attribute__(( stdcall)) instead? And
what about the other platform I tried?

--
Eric.Sosman@sun .com

**Keith Thompson** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

jacob navia <jacob@nospam.c omwrites:

Keith Thompson wrote:

>jacob navia <jacob@nospam.c omwrites:

>>Ian Collins wrote:
>>>Bartc wrote:
>>>>I'm mixing C and ASM, and for calling ASM from C, I just happened
>>>>to use the __stdcall convention (using C convention is not
>>>>practical for other reasons).
>>>>>
>>>What is __stdcall?
>>What's the point of showing your ignorance as it was a quality?
>>>
>>You do not know the subject matter?
>>>
>>Just stay silent! Is that too complicated?
>>>
>>>It's not C,
>>Of course it is. It is a common extension.
>>>
>>>so it must be platform specific,
>>no, it isn't

>>
>"_stdcall" isn't platform-specific? Seriously?
>>

#ifndef STDCALL
#define STDCALL __attribute__(( stdcall))
#endif

What does defining "STDCALL" have to do with "__stdcall" ? They're two
different identifiers, you know.

I suppose your point is that gcc supports a feature that's similar to
"__stdcall" , but uses the syntax "__attribute__( (stdcall))". So two
different platforms support a similar feature using radically
different syntax. If I were sufficiently motivated, I'm sure I could
find another platform that either supports it with yet another
different syntax, or doesn't support it at all.

"__stdcall" is platform-specific.

--
Keith Thompson (The_Other_Keit h) <kst-u@mib.org>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

**Ian Collins** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

jacob navia wrote:

Ian Collins wrote:

>Bartc wrote:

>>I'm mixing C and ASM, and for calling ASM from C, I just happened to
>>use the __stdcall convention (using C convention is not practical for
>>other reasons).
>>>

>What is __stdcall?

>
>
Just stay silent! Is that too complicated?
>

Fool, if you read the bit of my post you snipped - "try a group for your
platform, you'll get more help there." - you would see I was attempting
to help the OP.

>

>It's not C,

>
Of course it is. It is a common extension.
>

Not on any platform I use, and that's quite a few.

>so it must be platform specific,

>
no, it isn't
>

Eric's already shown you that is is.

--
Ian Collins.

**jacob navia** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

Eric Sosman wrote:

... but you said __stdcall wasn't platform-specific, so
why do I have to write __attribute__(( stdcall)) instead? And
what about the other platform I tried?
>

Go to the kindergarten then. There you will find all answers

--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique

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**jacob navia** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

Keith Thompson wrote:

jacob navia <jacob@nospam.c omwrites:

>Keith Thompson wrote:

>>jacob navia <jacob@nospam.c omwrites:
>>>Ian Collins wrote:
>>>>Bartc wrote:
>>>>>I'm mixing C and ASM, and for calling ASM from C, I just happened
>>>>>to use the __stdcall convention (using C convention is not
>>>>>practica l for other reasons).
>>>>>>
>>>>What is __stdcall?
>>>What's the point of showing your ignorance as it was a quality?
>>>>
>>>You do not know the subject matter?
>>>>
>>>Just stay silent! Is that too complicated?
>>>>
>>>>It's not C,
>>>Of course it is. It is a common extension.
>>>>
>>>>so it must be platform specific,
>>>no, it isn't
>>"_stdcall" isn't platform-specific? Seriously?
>>>

>#ifndef STDCALL
>#define STDCALL __attribute__(( stdcall))
>#endif

>
What does defining "STDCALL" have to do with "__stdcall" ? They're two
different identifiers, you know.
>
I suppose your point is that gcc supports a feature that's similar to
"__stdcall" , but uses the syntax "__attribute__( (stdcall))". So two
different platforms support a similar feature using radically
different syntax. If I were sufficiently motivated, I'm sure I could
find another platform that either supports it with yet another
different syntax, or doesn't support it at all.
>
"__stdcall" is platform-specific.
>

What piss me off of this regulars is that when they are proved
wrong they insist

--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique

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**jacob navia** · Jun 27 '08, 07:32 PM

Re: __stdcall alternative

Ian Collins wrote:

jacob navia wrote:

>Ian Collins wrote:

>>Bartc wrote:
>>>I'm mixing C and ASM, and for calling ASM from C, I just happened to
>>>use the __stdcall convention (using C convention is not practical for
>>>other reasons).
>>>>
>>What is __stdcall?

>>
>Just stay silent! Is that too complicated?
>>

Fool, if you read the bit of my post you snipped - "try a group for your
platform, you'll get more help there." - you would see I was attempting
to help the OP.
>

>>It's not C,

>Of course it is. It is a common extension.
>>

Not on any platform I use, and that's quite a few.
>

>>so it must be platform specific,

>no, it isn't
>>

Eric's already shown you that is is.
>

And I showed Eric and you and Thompson that is supported
on gcc/MSVC/Lcc-win/Watcom/Borland and what have you

what piss me off of this regulars is that when proved wrong
they insist

--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique

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__stdcall alternative

__stdcall alternative

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