This is a MFC of all the commits listed below.
My original goal of this change was to only merge the move of the tests
from tools/regression/bin/ into the new layout (which include tests for
sh(1) and other tools as well). However, doing so is tricky due to the
ongoing work in sh(1) and, especially, the many changes to its tests
since stable/10 was first branched.
Merging everything is the simplest way to achieve this goal and, as a
bonus point, we get various fixes and miscellaneous improvements into
the branch.
Per jilles' suggestion, I'm avoiding the merge of a couple of changes
(r256850 and r257506) that required depending kernel changes. I'm also
avoiding very recent changes that have not had a long enough time to be
validated in current.
This is "make tinderbox" clean.
r256735 sh: Remove one syscall when waiting for a foreground job.
r257399 sh: Allow trapping SIGINT/SIGQUIT after ignore because of '&'.
r257504 sh: Reorder union node to reduce its size on 64-bit platforms.
r257920 sh: Add a test case for would-be assignments that are not due to quoting.
r257929 sh: Properly quote alias output from command -v.
r258489 sh: Add tests for the </dev/null implicit in a background command.
r258533 sh: Add more tests for the </dev/null implicit in a background command.
r258535 sh: Make <&0 disable the </dev/null implicit in a background command.
r258776 sh: Prefer memcpy() to strcpy() in most cases. Remove the scopy macro.
r259047 sh: Split set -x output into a separate function.
r259210 Migrate tools/regression/bin/ tests to the new layout.
r259844 sh: Remove an unused variable.
r259846 sh: Initialize OPTIND=1 even if it came from the environment.
r259874 sh: Simplify code related to PPID variable.
r259946 sh: Don't check input for non-whitespace if history is disabled.
r260246 sh(1): Discourage use of -e.
r260506 Run the sh(1) and test(1) tests as unprivileged.
r260586 Mark the bin/pax tests as requiring perl.
r260634 Use TAP_TESTS_PERL to register the legacy_test in bin/pax.
r260635 Replace hand-crafted Kyuafiles with automatic generation.
r260654 sh: Remove SIGWINCH handler and just check for resize before every read.
r261121 sh: Add test for nested alias.
r261125 sh: Solve the alias recursion problem in a less hackish way.
r261141 sh: Do not depend on parse/execute split in new alias test.
r261160 sh: Add tests for alias names after another alias.
r261192 sh: Allow aliases to force alias substitution on the following word.
r262533 sh: Make expari() static.
r262565 sh: Do not corrupt internal representation if LINENO inner expansion fails.
r262697 sh: Simplify expari().
Reviewed by: jilles
The change in r238888 was incomplete. It was still possible for a trapped
signal to arrive before the shell went to sleep (sigsuspend()) because a
check was missing or because the signal arrived before in_waitcmd was set.
On SMP, this bug sometimes caused the builtins/wait4.0 test to take 1 second
to execute; it then might or might not fail. On UP, the test almost always
failed.
If a job is specified to 'wait', wait for it to complete. Formerly, in
interactive mode, the job was deleted if it stopped.
If no jobs are specified in interactive mode, 'wait' still waits for all jobs
to complete or stop.
In non-interactive mode, WUNTRACED is not passed to wait3() so stopped jobs
are not detected.
PR: bin/181435
This is required by POSIX, at least for pids that are not known child
processes.
Other problems with job specifications still cause wait to abort with
exit status 2.
PR: 176916
This is only part of the PR; the behaviour for unknown/invalid pids/jobs
remains unchanged (aborts the builtin with status 2).
PR: 176916
Submitted by: Vadim Goncharov
It now passes WARNS=7 with clang on i386.
GCC 4.2.1 does not understand setjmp() properly so will always trigger
-Wuninitialized. I will not add the volatile keywords to suppress this.
If syntactically invalid job identifiers are to be taken as jobs that exited
with status 127, this should not apply to options, so that we can add
options later if need be.
Accessing sys_siglist directly requires rtld to copy it from libc to the sh
executable's BSS. Also, strsignal() will put in the signal number for
unknown signals (FreeBSD-specific) so we need not do that ourselves.
Unfortunately, there is no function for sys_signame.
This reduces code duplication and code size.
/usr/bin/printf is not affected.
Side effect: different error messages when certain builtins are passed
invalid options.
When waiting for child processes using "wait" or if "set -T" is in effect, a
signal interrupts the wait. Make sure there is no window where the signal
handler may be invoked (setting a flag) just before going to sleep.
There is a similar race condition in the shell language, but scripts can
avoid it by exiting from the trap handler or enforcing synchronization using
a fifo.
If SIGCHLD is not trapped, a signal handler must be installed for it. Only
install this handler for the duration of the wait to avoid triggering
unexpected [EINTR] errors elsewhere.
Note that for some reason only SIGINT and SIGQUIT interrupt a "wait"
command. This remains the case.
This uses vfork() for simple commands and command substitutions containing a
single simple command, invoking an external program under certain conditions
(no redirections or variable assignments, non-interactive shell, no job
control). These restrictions limit the amount of code executed in a vforked
child.
There is a large speedup (for example 35%) in microbenchmarks. The
difference in buildkernel is smaller (for example 0.5%) but still
statistically significant. See
http://lists.freebsd.org/pipermail/freebsd-hackers/2012-January/037581.html
for some numbers.
The use of vfork() can be disabled by setting a variable named
SH_DISABLE_VFORK.
Have mkbuiltins write the prototypes for the *cmd functions to builtins.h
instead of builtins.c and include builtins.h in more .c files instead of
duplicating prototypes for *cmd functions in other headers.
In optimized command substitution, save and restore any variables changed by
expansions (${var=value} and $((var=assigned))), instead of trying to
determine if an expansion may cause such changes.
If $! is referenced in optimized command substitution, do not cause jobs to
be remembered longer.
This fixes $(jobs $!) again, simplifies the man page and shortens the code.
These are called "shell procedures" in the source.
If execve() failed with [ENOEXEC], the shell would reinitialize itself
and execute the program as a script. This requires a fair amount of code
which is not frequently used (most scripts have a #! magic number).
Therefore just execute a new instance of sh (_PATH_BSHELL) to run the
script.
When a foreground job exits on a signal, a message is printed to stdout
about this. The buffer was not flushed after this which could result in the
message being written to the wrong file if the next command was a builtin
and had stdout redirected.
Example:
sh -c 'kill -9 $$'; : > foo; echo FOO:; cat foo
Reported by: gcooper
MFC after: 1 week
This allows specifying a %job (which is equivalent to the corresponding
process group).
Additionally, it improves reliability of kill from sh in high-load
situations and ensures "kill" finds the correct utility regardless of PATH,
as required by POSIX (unless the undocumented %builtin mechanism is used).
Side effect: fatal errors (any error other than kill(2) failure) now return
exit status 2 instead of 1. (This is consistent with other sh builtins, but
not in NetBSD.)
Code size increases about 1K on i386.
Obtained from: NetBSD
* Prefer kill(-X) to killpg(X).
* Remove some dead code.
* No additional SIGINT is needed if int_pending() is already true.
No functional change is intended.
The code to translate the internal representation to text did not know about
various additions to the internal representation since the original ash and
therefore wrote binary stuff to the terminal.
The code is used in the jobs command and similar output.
Note that the output is far from complete and mostly serves for recognition
purposes.
If describing the status of a pipeline, write all elements of the pipeline
and show the status of the last process (which would also end up in $?).
Only write one report per job, not one for every process that exits.
To keep some earlier behaviour, if any process started by the shell in a
foreground job terminates because of a signal, write a message about the
signal (at most one message per job, however).
Also, do not write messages about signals in the wait builtin in
non-interactive shells. Only true foreground jobs now write such messages
(for example, "Terminated").
In r208489, I added code to reap zombies when forking new processes, to
limit the amount of zombies. However, this can lead to marking a job as done
or stopped if it consists of multiple processes and the first process ends
very quickly. Fix this by only checking for zombies before forking the first
process of a job and not marking any jobs without processes as done or
stopped.
The getpgid() call will fail if the first process in the job has already
terminated, resulting in output of "-1".
The pgid of a job is always the pid of the first process in the job and
other code already relies on this.
- Use %t to print ptrdiff_t values.
- Cast a ptrdiff_t value explicitly to int for a field width specifier.
While here, sort includes.
Submitted by: Garrett Cooper
Unless $! has been referenced for a particular job or $! still contains that
job's pid, forget about it after it has terminated. If $! has been
referenced, remember the job until the wait builtin has reported its
completion (either with the pid as parameter or without parameters).
In interactive mode, jobs are forgotten after termination has been reported,
which happens before primary prompts and through the jobs builtin. Even
then, though, remember a job if $! has been referenced.
This is similar to what is suggested by POSIX and should fix most memory
leaks (which also tend to cause sh to use more CPU time) with long running
scripts that start background jobs.
Caveats:
* Repeatedly referencing $! without ever doing 'wait', like
while :; do foo & echo started foo: $!; sleep 60; done
will still use a lot of memory and CPU time in the long run.
* The jobs and jobid builtins do not cause a job to be remembered for longer
like expanding $! does.
PR: bin/55346
is enabled.
This already worked if without job control.
In either case, this depends on it that a process that terminates due to
SIGINT exits on it (so not with status 1, or worse, 0).
Example:
sleep 5; echo continued
This does not print "continued" any more if sleep is aborted via ctrl+c.
MFC after: 1 month
This prevents accumulating huge amounts of zombies if a script executes
many background commands but no external commands or subshells.
Note that zombies will not be reaped during long calculations (within
the shell process) or read builtins, but those actions do not create
more zombies.
The terminated background commands will also still be remembered by the
shell.
PR: bin/55346
Reset the exception handler in the child to main's.
This avoids inappropriate double cleanups or shell duplication when the
exception is caught, such as 'fc' and future 'command eval' and 'command .'.
* increase buffer size from 100 to 256 bytes
* remove implied flush from out2str(), in particular this avoids unnecessary
flushing in the middle of a -x tracing line
* rename dprintf() to out2fmt_flush(), make it flush out2 and use this
function in various places where flushing is desired after an error
message
process leader for each job. Now the last specified option for the output
format (-l, -p or -s) wins, previously -s trumped -l.
PR: 99926
Submitted by: Ed Schouten and novel (patches modified by me)
