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
..

llvm/lib/Support/Unix README
===========================

This directory provides implementations of the lib/System classes that
are common to two or more variants of UNIX. For example, the directory
structure underneath this directory could look like this:

Unix           - only code that is truly generic to all UNIX platforms
  Posix        - code that is specific to Posix variants of UNIX
  SUS          - code that is specific to the Single Unix Specification
  SysV         - code that is specific to System V variants of UNIX

As a rule, only those directories actually needing to be created should be
created. Also, further subdirectories could be created to reflect versions of
the various standards. For example, under SUS there could be v1, v2, and v3
subdirectories to reflect the three major versions of SUS.