compat.fribidi

// compat.fribidi — the Unicode bidirectional algorithm, on text that needs it.
//
// WHAT THIS ASSERTS AND WHY
//
// The tables are the whole package. fribidi's seven `.tab.i` files encode the
// Unicode Character Database, and a build that compiled none of them would
// still link, still run, and quietly treat Arabic as left-to-right. So every
// check below asks the library a question whose answer is IN a table:
//
//   the Unicode version    fribidi-unicode-version.h, generated upstream
//   bidi character types   bidi-type.tab.i
//   base direction         the resolution algorithm over those types
//   visual reordering      UAX #9 itself, the reason pango needs this
//   mirroring              mirroring.tab.i — "(" becomes ")" in an RTL run
//   joining types          joining-type.tab.i, which shapes Arabic
//
// A pass here means the tarball's pre-generated tables really were compiled —
// the claim that lets this be a descriptor instead of a fork.

#ifdef __linux__

// ⚠️ WRAPPED IN extern "C". fribidi's public headers have no `extern "C"` of
// …