Xref: news2.mv.net comp.os.msdos.djgpp:5941
From: Pål-Kristian Engstad <engstad AT funcom DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: How to write ASM member functions?
Date: Sat, 13 Jul 1996 03:44:10 +0200
Organization: Funcom Oslo AS
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References: <tparvine DOT 836909964 AT niksula DOT hut DOT fi>
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To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

Tero Lauri Juhani Parvinen wrote:
> 
> Can I write a classes member functions in asm? I would like to define them in
> a .S file, not inline. The obvious problem is that I can't just define the
> function like _function (C-style). I looked at some .o files and found
> something like _func__5MyClass_iiPc... I think the iiPc means that the
> parameters are int, int, *char, but what about that weird 5?

Well, you shouldn't. This is because the C++ name mangling might change
in the future. Instead, you should make inline C++ wrapping functions:

extern "C" {
	/* Place C and assembly functions here. */
	int myAssemblyStub(int a, int b);
};

class AsmClass {
	:
	:
	int myFunc(int a, int b = 0) { return myAssemlyStub(a, b); }
};

> Is there a simpler way to do this or does someone know what the number
> stands for?

Well, if you really want to know, the numbers usually stand for the
number of characters in a struct/class name. For instance:

_play__4game_ii  --->  game::play(int, int);
_play__4game_RC8fix16_16  -->  game::play(const fix16_16 &);

Note that the program cxxfilt.exe converts mangled names back to C++ names.
Also note that the macro
	__FUNCTION__ returns the mangled name, while
	__PRETTY_FUNCTION__ returns the C++ name.

PKE.
-- 
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| Pål-Kristian Engstad | engstad AT funcom DOT com  | Games programmer, PSX |
| Funcom Oslo AS       | Ph +47 22 42 01 02  | developer & Linux Fan |
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