[OpenMP] Generate better diagnostics for cancel and cancellation point
checkNestingOfRegions uses CancelRegion to determine whether cancel and
cancellation point are valid in the given nesting. This leads to unuseful
diagnostics if CancelRegion is invalid. The given test case has produced:
region cannot be closely nested inside 'parallel' region
As a solution, introduce checkCancelRegion and call it first to get the
expected error:
one of 'for', 'parallel', 'sections' or 'taskgroup' is expected
Differential Revision: https://reviews.llvm.org/D30135
llvm-svn: 295808
3 files changed