Re: [Sdcc-user] Possible changes to inline assembler syntax

[Philipp K. K. <pk...@sp...>]

> 
>> Since people like form 1, I'd now think we should keep it, but drop
>> #pragma sdcc_hash. That looks like a better way forward and also
>> solves the issues.
> 
> When this pragma is dropped does that mean it is no longer possible to 
> use the # for an immediate operand?

You can still use a plain # (it already works now without using the pragma):

void h(void)
{
__asm
	add	a, #3
__endasm;
}

> Or will it be limited to use outside of a macro? I wouldn't even know 
> how to escape the #.

The C standard requires "Each # preprocessing token in the replacement 
list for a function-like macro shall be followed by a parameter as the 
next preprocessing token in the replacement list." (see section 6.10.3.2 
of the current C2X standard N2912). Which makes sense, since in the 
standard, # is meant for stringizing macro arguments. The #pragma 
sdcc_hash is used to overide that.

lib/ds400/ds400.rom.c currently has the following lines:

// This macro is invalid for the standard C preprocessor, since it
// includes a hash character in the expansion, hence the SDCC specific
// pragma.
#pragma sdcc_hash +
#define ROMCALL(x) \
         mov     R6_B3, #(x & 0xff)              \
         mov     R7_B3, #((x >> 8) & 0xff)       \
         lcall   __romcall

And then uses this macro from within __asm / __endasm. This will have to 
be changed to e.g.:

#define HASH #
#define ROMCALL(x) \
         mov     R6_B3, HASH(x & 0xff)              \
         mov     R7_B3, HASH((x >> 8) & 0xff)       \
         lcall   __romcall

Philipp