On 10/2/19 8:46 AM, Tom Lane wrote:
Joe Nelson <j...@begriffs.com> writes:
Isaac Morland wrote:
I hope you'll forgive a noob question. Why does the "After"
initialization for the boolean array have {0} rather than {false}?
I think using a value other than {0} potentially gives the incorrect
impression that the value is used for *all* elements of the
array/structure, whereas it is only used for the first element.
There's been something vaguely bothering me about this proposal,
and I think you just crystallized it.
Using {false} may encourage the unwary to try
bool foo[2] = {true};
which will not set all elements to true.
Right. I think that in general it's bad practice for an initializer
to not specify all fields/elements of the target. It is okay in the
specific case that we're substituting for a memset(..., 0, ...).
Perhaps we could make this explicit by using a coding style like
/* in c.h or some such place: */
#define INIT_ALL_ZEROES {0}
/* in code: */
Datum values[N] = INIT_ALL_ZEROES;
and then decreeing that it's not project style to use a partial
initializer other than in this way.
There are numerous locations in the code that raise warnings when
-Wmissing-field-initializers is handed to gcc. See, for example,
src/backend/utils/adt/formatting.c where
static const KeyWord NUM_keywords[]
is initialized, and the code comment above that disclaims the need to
initialize is_digit and date_mode. Are you proposing cleaning up all
such incomplete initializations within the project?
I understand that your INIT_ALL_ZEROS macro does nothing to change
whether -Wmissing-field-initializers would raise a warning. I'm
just asking about the decree you propose, and I used that warning flag
to get the compiler to spit out relevant examples.
mark
