Re: [PoC] Improve dead tuple storage for lazy vacuum

On Thu, Mar 7, 2024 at 1:49 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> odr-violation seems to refer to One Definition Rule (ODR). According
> to Wikipedia[1]:
>
> The One Definition Rule (ODR) is an important rule of the C++
> programming language that prescribes that classes/structs and
> non-inline functions cannot have more than one definition in the
> entire program and template and types cannot have more than one
> definition by translation unit. It is defined in the ISO C++ Standard
> (ISO/IEC 14882) 2003, at section 3.2. Some other programming languages
> have similar but differently defined rules towards the same objective.
>
> I don't fully understand this concept yet but are these two different
> build failures related?

I thought it may have something to do with the prerequisite commit
that moved some symbols from bitmapset.c to .h:

/* Select appropriate bit-twiddling functions for bitmap word size */
#if BITS_PER_BITMAPWORD == 32
#define bmw_leftmost_one_pos(w) pg_leftmost_one_pos32(w)
#define bmw_rightmost_one_pos(w) pg_rightmost_one_pos32(w)
#define bmw_popcount(w) pg_popcount32(w)
#elif BITS_PER_BITMAPWORD == 64
#define bmw_leftmost_one_pos(w) pg_leftmost_one_pos64(w)
#define bmw_rightmost_one_pos(w) pg_rightmost_one_pos64(w)
#define bmw_popcount(w) pg_popcount64(w)
#else
#error "invalid BITS_PER_BITMAPWORD"
#endif

...but olingo's error seems strange to me, because it is complaining
of pg_leftmost_one_pos, which refers to the lookup table in
pg_bitutils.c -- I thought all buildfarm members used the bitscan
instructions.

grassquit is complaining of pg_popcount64, which is a global function,
also in pg_bitutils.c. Not sure what to make of this, since we're just
pointing symbols at things which should have a single definition...