Added utility to launch tests on a target remotely.

[aorlov]

Summary

Runs an executable on a remote host.
This is meant to be used as an executor when running the LLVM and the Libraries tests on a target.

This follows the discussion in https://reviews.llvm.org/D83429, and the code is based on libcxx/utils/ssh.py.

[aorlov]

Changed the parameter --test-executable to --exec-pattern;
Used regex instead of fnmatch;
Fixed bugs that appeared in case of complicated command line.
Note I used the following command line for tests:
python remote-exec.py --host user@host --execdir llvm-project/build/runtimes/runtimes-bins/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/Output/cin.sh.cpp.dir --codesign_identity "" --env "" -- echo "123" "|" llvm-project/build/runtimes/runtimes-bins/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/Output/cin.sh.cpp.dir/t.tmp.exe ">" t.tmp.out "&&" grep -e "The number is 123!" t.tmp.out

[vvereschaka]

LGTM,

also tested with the aarch64/armv7 compiler-rt tests on Windows cross builders.

[ldionne]

Do we still need this utility if we add --test-executable (or as you did --exec-pattern) to the original libcxx ssh.py?

[ldionne]

In D89349#2349038, @ldionne wrote:

Do we still need this utility if we add --test-executable (or as you did --exec-pattern) to the original libcxx ssh.py?

Note, what happened is that I spoke with @broadwaylamb offline and he made a point that supporting --test-executable was worthwhile, and it would remove existing hacks in ssh.py. In the meantime, I also came across other use cases that would be helped by having --test-executable, which is why I came back and changed my mind on D83429.

[aorlov]

Since we use this utility in multiple projects now, it is better to have it outside the libc++ project, so we would not introduce unneeded inter-project dependencies just because of shared tools.

It might make sense to change the libc++ tests to use this utility, to remove the redundancy. I’ll be glad to propose a patch for that if you would like me to. Please let me know.

[ldionne]

In D89349#2350506, @aorlov wrote:

Since we use this utility in multiple projects now, it is better to have it outside the libc++ project, so we would not introduce unneeded inter-project dependencies just because of shared tools.

It might make sense to change the libc++ tests to use this utility, to remove the redundancy. I’ll be glad to propose a patch for that if you would like me to. Please let me know.

Out of curiosity, where do you use it?

llvm/utils/remote-exec.py

+#!/usr/bin/env python
+#===----------------------------------------------------------------------===##
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+#===----------------------------------------------------------------------===##
+
+"""
+Runs an executable on a remote host.
+
+This is meant to be used as an executor when running the LLVM and the Libraries
+tests on a target.
+"""
+
+import argparse
+import os
+import posixpath
+import shlex
+import subprocess
+import sys
+import tarfile
+import tempfile
+import re
+
+def ssh(args, command):
+    cmd = ['ssh', '-oBatchMode=yes']
+    if args.extra_ssh_args is not None:
+        cmd.extend(shlex.split(args.extra_ssh_args))
+    return cmd + [args.host, command]
+
+
+def scp(args, src, dst):
+    cmd = ['scp', '-q', '-oBatchMode=yes']
+    if args.extra_scp_args is not None:
+        cmd.extend(shlex.split(args.extra_scp_args))
+    return cmd + [src, '{}:{}'.format(args.host, dst)]
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--host', type=str, required=True)
+    parser.add_argument('--execdir', type=str, required=True)
+    parser.add_argument('--extra-ssh-args', type=str, required=False)
+    parser.add_argument('--extra-scp-args', type=str, required=False)
+    parser.add_argument('--codesign_identity', type=str, required=False, default=None)
+    parser.add_argument('--env', type=str, nargs='*', required=False, default=dict())
+
+    # Note: The default value is for the backward compatibility with a hack in 
+    # libcxx test suite.
+    # If an argument is a file that ends in `.tmp.exe`, assume it is the name
+    # of an executable generated by a test file. We call these test-executables
+    # below. This allows us to do custom processing like codesigning test-executables
+    # and changing their path when running on the remote host. It's also possible
+    # for there to be no such executable, for example in the case of a .sh.cpp
+    # test.
+    parser.add_argument('--exec-pattern', type=str, required=False, default='.*\.tmp\.exe',
+                        help='The name regex pattern of the executables generated by \
+                              a test file. Specifying it allows us to do custom \
+                              processing like codesigning test-executables \
+                              and changing their path when running on \
+                              the remote host. It\'s also possible for there \
+                              to be no such executable, for example in \
+                              the case of a .sh.cpp test.')
+
+    parser.add_argument("command", nargs=argparse.ONE_OR_MORE)
+    args = parser.parse_args()
+    commandLine = args.command
+
+    # Create a temporary directory where the test will be run.
+    # That is effectively the value of %T on the remote host.
+    tmp = subprocess.check_output(
+                  ssh(args, 'mktemp -d /tmp/llvm.XXXXXXXXXX'),
+                  universal_newlines=True
+              ).strip()
+
+    isExecutable = lambda exe: re.match(args.exec_pattern, exe) and os.path.exists(exe)
+    pathOnRemote = lambda file: posixpath.join(tmp, os.path.basename(file))
+
+    try:
+        # Do any necessary codesigning of test-executables found in the command line.
+        if args.codesign_identity:
+            for exe in filter(isExecutable, commandLine):
+                subprocess.check_call(
+                    ['xcrun', 'codesign', '-f', '-s', args.codesign_identity, exe],
+                    env={})
+
+        # tar up the execution directory (which contains everything that's needed
+        # to run the test), and copy the tarball over to the remote host.
+        try:
+            tmpTar = tempfile.NamedTemporaryFile(suffix='.tar', delete=False)
+            with tarfile.open(fileobj=tmpTar, mode='w') as tarball:
+                tarball.add(args.execdir, arcname=os.path.basename(args.execdir))
+
+            # Make sure we close the file before we scp it, because accessing
+            # the temporary file while still open doesn't work on Windows.
+            tmpTar.close()
+            remoteTarball = pathOnRemote(tmpTar.name)
+            subprocess.check_call(scp(args, tmpTar.name, remoteTarball))
+        finally:
+            # Make sure we close the file in case an exception happens before
+            # we've closed it above -- otherwise close() is idempotent.
+            tmpTar.close()
+            os.remove(tmpTar.name)
+
+        # Untar the dependencies in the temporary directory and remove the tarball.
+        remoteCommands = [
+            'tar -xf {} -C {} --strip-components 1'.format(remoteTarball, tmp),
+            'rm {}'.format(remoteTarball)
+        ]
+
+        # Make sure all executables in the remote command line have 'execute'
+        # permissions on the remote host. The host that compiled the test-executable
+        # might not have a notion of 'executable' permissions.
+        for exe in filter(isExecutable, commandLine):
+            remoteCommands.append('chmod +x {}'.format(pathOnRemote(exe)))
+
+        # Execute the command through SSH in the temporary directory, with the
+        # correct environment. We tweak the command line to run it on the remote
+        # host by transforming the path of test-executables to their path in the
+        # temporary directory on the remote host.
+        for i, x in enumerate(commandLine):
+            if isExecutable(x):
+                commandLine[i] = pathOnRemote(x)
+        remoteCommands.append('cd {}'.format(tmp))
+        if args.env:
+            remoteCommands.append('export {}'.format(' '.join(args.env)))
+        remoteCommands.append(subprocess.list2cmdline(commandLine))
+
+        # Finally, SSH to the remote host and execute all the commands.
+        rc = subprocess.call(ssh(args, ' && '.join(remoteCommands)))
+        return rc
+
+    finally:
+        # Make sure the temporary directory is removed when we're done.
+        subprocess.check_call(ssh(args, 'rm -r {}'.format(tmp)))
+
+
+if __name__ == '__main__':
+    exit(main())