Pavel Labath d04333d38b Recommit "[Support] Add RetryAfterSignal helper function"
The difference from the previous version is the use of decltype, as the
implementation of std::result_of in libc++ did not work correctly for
variadic function like open(2).

Original summary:
This function retries an operation if it was interrupted by a signal
(failed with EINTR). It's inspired by the TEMP_FAILURE_RETRY macro in
glibc, but I've turned that into a template function. I've also added a
fail-value argument, to enable the function to be used with e.g.
fopen(3), which is documented to fail for any reason that open(2) can
fail (which includes EINTR).

The main user of this function will be lldb, but there were also a
couple of uses within llvm that I could simplify using this function.

Reviewers: zturner, silvas, joerg

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D33895

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306671 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-29 13:15:31 +00:00
..
2017-06-20 20:51:51 +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.