Problems with parsing "Extended Asm"

[Druidos]

When I was tried to parse source with several asm instructions (described at http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html)
I faced with fails to parse similar pieces:

1 . void read_tsc(void) {
long val;
asm("rdtsc" : "=A" (val));
}

whereas asm(''nothing") mistakenly recognized as function call.

2 . void read_tsc(void) {
long val;
asm volatile("rdtsc" : "=A" (val));
}

3 . void read_tsc(void) {
long fpenv;
asm(""mtfsf 255,%0"
: :
"f" (fpenv));
}

I suppose that highlighted parts are different states for context-free grammar used by pycparserext in whole.

[inducer]

Here's the code that parses that stuff. Can you try and cook up a patch?

[Druidos]

There is my patch for this issue: (probably it isn't accurate)
Druidos@8f8201a

Also tests are shown that GNUCGenerator has problem with reconstruction asm notation.

[inducer]

I've merged your changes, thanks! How would I reproduce the asm notation reconstruction issue?

[Druidos]

Sorry for late response.

Example illustrated problem with GnuCGenerator is in test_asm_volatile_2():

I have source:
void read_tsc(void) {
long val;
asm volatile("rdtsc" : "=A" (val));
}

but as result of generation I have output with 4 components in asm:
void read_tsc(void)
{
long val;
asm volatile("rdtsc" : "=A"(val) : : )
;
}

I suppose that problem corresponds to visit_Asm() because it extends components by 3 independently on witch asm components are None. After this generic_visit() method from on node=None returns empty string.

        if (n.output_operands is not None
                or n.input_operands is not None
                or n.clobbered_regs is not None):
            components.extend([
                n.output_operands,
                n.input_operands,
                n.clobbered_regs,
                ])

[inducer]

Sorry for the dumb question: Is the four-component version with two empty components not equivalent to the two-component version?