PetscFunctionBegin has logic to to avoid overflowing the array, but the
stack still gets skewed because PetscFunctionReturn always pops the
stack. This is a problem because many simple examples already overflow
the stack at some point, resulting in a truncated stack in the error
messages. This macro is currently defined at 15, with fieldsplits and
V-cycles, it's easy to exceed 30 frames.
The stack skew problem could be overcome by introducing a new local
variable with another level of nesting, something like
#define PetscFunctionBegin { \
PetscTruth _petscstackpushed = petscstack->currentsize < PETSCSTACKSIZE; \
ExistingPetscFunctionBegin;
#define PetscFunctionReturn(n) \
{if (_petscstackpushed) PetscStackPop; return (n);} \
}
But I'm not a huge fan of doing this sort of thing with macros and it's
still easy enough to get an error from deeper than 15 frames, so I want
to increase the PETSCSTACKSIZE regardless of whether the macro hack
above is also done. Is there a reason not to use a biggish number like
50 or more?
Jed
