.metaconf-exclusions.txt

# This file is used when building the Configure script from the metaconfig
# units. Ordinarily, if any *.c or *.h or *.sh file mentions a symbol that can
# be provided by a metaconfig unit, the generated Configure will include the
# relevant probe. But in some cases, that's inappropriate: we have symbols that
# we no longer need to probe for, but must define in perl.h for backwards
# compatibilty with XS modules. Also, our C files contain tokens like "index"
# that are used as the names of Perl builtins, but would be treated by
# metaconfig as implicit requests for a particular unit that we don't need.
#
# Previously, we've used customised "stub" versions of metaconfig units to
# handle this situation, but that doesn't scale (and, in particular, requires
# us to maintain those customised units for as long as the relevant symbols are
# defined by the units in the upstream dist package).
#
# A better approach is to list those symbols here (and invoke metaconfig with
# the "-X .metaconf-exclusions.txt" option when generating Configure); that
# will prevent the relevant units from being used.
#
# See also metaconfig.h, which works in the other direction — it forces units
# to be included, even before specific code using the relevant symbols has been
# written.

I_LIMITS
I_STDARG
index
rindex
const