Jordan Rose b2ae4f8e41 Support for dumping current PrettyStackTrace on SIGINFO (Ctrl-T)
Support SIGINFO (and SIGUSR1 for POSIX purposes) to tell what
long-running jobs are doing, as inspired by BSD tools (including on
macOS), by dumping the current PrettyStackTrace.

This adds a new kind of signal handler for non-fatal "info" signals,
similar to the "interrupt" handler that already exists for SIGINT
(Ctrl-C). It then uses that handler to update a "generation count"
managed by the PrettyStackTrace infrastructure, which is then checked
whenever a PrettyStackTraceEntry is pushed or popped on each
thread. If the generation has changed---i.e. if the user has pressed
Ctrl-T---the stack trace is dumped, though unfortunately it can't
include the deepest entry because that one is currently being
constructed/destructed.

https://reviews.llvm.org/D63750

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365911 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-12 16:05:09 +00:00
..