Probe for preadv/pwritev in a more macOS-friendly way.
Apple's mechanism for dealing with functions that are available
in only some OS versions confuses AC_CHECK_FUNCS, and therefore
AC_REPLACE_FUNCS. We can use AC_CHECK_DECLS instead, so long as
we enable -Werror=unguarded-availability-new. This allows people
compiling for macOS to control whether or not preadv/pwritev are
used by setting MACOSX_DEPLOYMENT_TARGET, rather than supplying
a back-rev SDK. (Of course, the latter still works, too.)
James Hilliard
Discussion: https://postgr.es/m/20210122193230.25295-1-james.hilliard1@gmail.com
Branch
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REL_14_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/e75da4f1b6c63523021e550f1a92c67d2b8a92fb
Modified Files
--------------
configure | 166 +++++++++++++++++++++++++++++++++++++-------
configure.ac | 11 ++-
src/include/pg_config.h.in | 14 ++--
src/include/port/pg_iovec.h | 4 +-
src/tools/msvc/Solution.pm | 4 +-
5 files changed, 161 insertions(+), 38 deletions(-)
