OpenEuphoria

1. ver 4.0 calling convention information ?

• Posted by bernie May 26, 2009
• 838 views

I need to know the following:

Is there more than one TYPE of routine_id returned from Euphoria ?
If so what creates each TYPE and when is it used ?

I need to know the calling conventions and who is responsible for
cleaning the stack for the following routines.

            Euphoria call type     routine receiving call\\  
CALL_FUNC  ( std or cdecl call ) ( clean stack for return ? )\\   
C_FUNC     ( std or cdecl call ) ( clean stack for return ? )\\  
CALL       ( std or cdecl call ) ( clean stack for return ? )\\   

3. Re: ver 4.0 calling convention information ?

• Posted by jimcbrown (admin) May 26, 2009
• 861 views

            Euphoria call type     routine receiving call\\  
CALL_FUNC  ( std or cdecl call ) ( clean stack for return ? )\\   
C_FUNC     ( std or cdecl call ) ( clean stack for return ? )\\  
CALL       ( std or cdecl call ) ( clean stack for return ? )\\   

There are two kinds of routine_ids, one returned by routine_id() and used by call_func() and call_proc(), and the other returned by define_c_func() and define_c_proc() and used by c_func() and c_proc().

You shouldn't need to worry about calling conventions here, but if you're curious the calling convention used by call_func() and call_proc() is euphoria specific. (The C backend stores the parameters and return value into special internal values and keeps track as it jumps around the IL code.) c_func() and c_proc() can use either STDCALL or C_DECL, which convention is used depends on a flag that is attached to the routine_id() returned by define_c_func() and define_c_proc() (you can force C_DECL on windows by prepending the function name with a '+').

Finally, you can call call_back() (with a routine_id() routine id) to get an address that is callable by call(). Likewise, you can use define_c_var() in place of either define_c_func() or define_c_proc() to get an address that can then be passed to call().

If using call(), you have to worry about calling convention. call_back() wraps tthe euphoria routine_id() with special code that assumes the C_DECL calling convention.

As to whether or not you need to clean the stack, that depends on STDCALL vs C_DECL. (The euphoria internal calling convention has no stack per-see to speak of that would need cleaning up.)

5. Re: ver 4.0 calling convention information ?

• Posted by mattlewis (admin) May 26, 2009
• 813 views

I don't understand why you're asking about being inside a euphoria function. It only matters what the assembler routine thinks, so that your call can do the right thing. The only way that knowing the calling convention of a euphoria routine would be in translated code, if you were to inline some assembly that returned from the function. Is that what you're doing?

Nothing has changed with respect to calling conventions. On windows, the default is stdcall, but you can use cdecl. On any other platform, you'll always use cdecl. This has always been the case.

What may be confusing here is that there are some idiosyncrasies regarding Watcom, where it seems to do the right thing regardless. I think that what it does is remember where the stack pointer should be, and restores it after a call returns regardless of the calling convention.

I don't understand what "ENTER and LEAVE" code means. Maybe you could post some non-working code so that we could take a look.

Matt

7. Re: ver 4.0 calling convention information ?

• Posted by jimcbrown (admin) May 26, 2009
• 844 views

How are you currently calling the assembler routine, and what calling convention is the assembler routine using?

If you call the assembler routine with call(), then you should not need to change anything. However, if you use c_func() or c_proc() then it may be a different story (in which case I suggest the assembly routine be changed to C_DECL calling convention).

9. Re: ver 4.0 calling convention information ?

• Posted by Critic May 27, 2009
• 859 views

Probably. Somehow it seems to be very hard to push a register and pop it afterwards. Very funny. See? It's just like I said: The amount of incompetence in this community is amazing and very entertaining.

11. Re: ver 4.0 calling convention information ?

• Posted by mattlewis (admin) May 27, 2009
• 911 views

The feeling is mutual.

Matt