Import all function documentations, return code reference
into the header files, as doc comments,
in the hopes of moving the CAref.html manual to docs.epics-controls.org,
which will be done in a later PR.
Also added doc comments to some other low-hanging fruits,
for example when plain comments where near, or when it was obvious to do so.
VxWorks does not mark abort() or exit() as noreturn.
Thus, functions declared noreturn which end in a call
to those functions cause a compiler warning on vxWorks.
Move isOkToBlock tracking to osdThread.
Targets except vxworks can store this flag in epicsThreadOSD.
Continue to use TLS w/ vxWorks.
Note that setting of isOkToBlock for "main" thread becomes lazy.
This flag causes EPICS to call abort() on assertion failures rather than
suspend the executing thread. With the epicsThreadSuspendSelf() behavior,
an IOC can end up in a difficult to detect error state where one or more
threads has essentially crashed due to an assertion failure.
This also matches the C behavior of assert(3)
For posix-ish systems, we previously checked that a path was relative
by simpy checking if it included a '/' character. This meant that you
could not, for example, do
```
$ cat foo.substitutions
file rel/to/bar.template {
}
$ msi -I /some/path foo.substitutions
```
where our template file is located at `/some/path/rel/to/bar.template`.
Note that relateive paths work differently on Windows, so we carve out
an exception there.
MS and MSI links do not propagate STAT and therefore do not propagate
AMSG, either. CA, CP and CPP links also do not propagate AMSG, but the
reason is technical: the message is not available over Channel Access.
Previously, there was no way to clear AMSG when setting a no-alarm
status: it kept the last error message, and it is strange to have a
record that has no alarm while showing an error. With this change, the
NAMSG field is treated the same as NSTA and NSEV: they are cleared when
their content is moved to STAT, SEVR, and AMSG.
