Inline assembly error

[TheEngineer]

I have the following snippet of inline assembly code in my ConstHeader.h file:

#define REG_AP(mr,reg_flag) \
  ({ \
		reg_flag \
		__asm__ ("pushl %0\n" :"=m"(*mr)); 
		__asm__ ("call  0x8000\n"); 
		}) /* FYI this is line 81 */

When compiling, I get the following error:

../ConstHeader.h:81: error: expected identifier or `(' before `}' token
../ConstHeader.h:81: error: expected identifier or `(' before `)' token

I have tried lots of ways to fix it but cannot figure out why I am getting this error. Any ideas?

[Salem]

a) how do you call the macro?
b) which compiler?

[Kennedy]

I have the following snippet of inline assembly code in my ConstHeader.h file:

#define REG_AP(mr,reg_flag) \
  ({ \
		reg_flag \
		__asm__ ("pushl %0\n" :"=m"(*mr)); 
		__asm__ ("call  0x8000\n"); 
		}) /* FYI this is line 81 */

When compiling, I get the following error:

../ConstHeader.h:81: error: expected identifier or `(' before `}' token
../ConstHeader.h:81: error: expected identifier or `(' before `)' token

I have tried lots of ways to fix it but cannot figure out why I am getting this error. Any ideas?

Looks like you need a couple of more \ after __asm__ lines. . .

[TheEngineer]

a) how do you call the macro?
b) which compiler?

a)It is called using the REG_AP() function in the main c file
b) gcc

[TheEngineer]

Looks like you need a couple of more \ after __asm__ lines. . .

Like this?:

#define REG_AP(mr,reg_flag) \
  ({ \
		reg_flag \
		__asm__ ("pushl %0\n" :"=m"(*mr)); \  /*pushes null onto stack */
		__asm__ ("call  0x8000\n"); \
})

I get the same error adding them in. Any other thoughts?

[Ronix]

At first glance, it seems that you need to move the *mr parameter to act as input since it's obviously not an output parameter (ie: change the first assembly line to `"pushl %0" : : "m"(*mr)). Also, I remember that `push' didn't really need any suffix when it was called in C, but I could be wrong about that.

Depending on what `reg_flag' is, you may also get errors there.

[TheEngineer]

At first glance, it seems that you need to move the *mr parameter to act as input since it's obviously not an output parameter (ie: change the first assembly line to `"pushl %0" : : "m"(*mr)). Also, I remember that `push' didn't really need any suffix when it was called in C, but I could be wrong about that.

Depending on what `reg_flag' is, you may also get errors there.

Hmmm...doesn't seem to make a difference. I still keep getting the error about the line with "})"

Also, I have several other commands like this in the file that do not cause errors. For instance, if I comment the posted commands out, I don't get any other similar errors

[Ronix]

Can you post an example invoking the macro? I don't really know what you could be passing as reg_flag, but maybe the error lies there...

[Salem]

> a)It is called using the REG_AP() function in the main c file
Nice (and useless)

As in
REG_AP(Im_a_bananna);

or
REG_AP(eax)

or
....



> __asm__ ("pushl %0\n" :"=m"(*mr)); \ /*pushes null onto stack */
The \ in macros MUST be the absolute last thing on a line to be treated as line folding.
Put the comment before the \

And yes, EVERY line of your multiline macro needs a \

[TheEngineer]

>
> __asm__ ("pushl %0\n" :"=m"(*mr)); \ /*pushes null onto stack */
The \ in macros MUST be the absolute last thing on a line to be treated as line folding.
Put the comment before the \

This was it, had to move the comment. Thanks!