Reject nested foralls in foreign imports (#16702)
authorRyan Scott <ryan.gl.scott@gmail.com>
Wed, 29 May 2019 15:52:02 +0000 (11:52 -0400)
committerMarge Bot <ben+marge-bot@smart-cactus.org>
Sat, 1 Jun 2019 03:56:27 +0000 (23:56 -0400)
commit45f88494293bea20cc3aca025ee6fe84087987ce
tree131f6175331925789d69f1d651e3463e21d4c98f
parent1d43d4a3e45d86261fa63591e99749cb7d3f68ed
Reject nested foralls in foreign imports (#16702)

This replaces a panic observed in #16702 with a simple error message
stating that nested `forall`s simply aren't allowed in the type
signature of a `foreign import` (at least, not at present).

Fixes #16702.
compiler/typecheck/TcForeign.hs
docs/users_guide/ffi-chap.rst
testsuite/tests/ffi/should_fail/T16702.hs [new file with mode: 0644]
testsuite/tests/ffi/should_fail/T16702.stderr [new file with mode: 0644]
testsuite/tests/ffi/should_fail/all.T