Add build-many-glibcs.py bot-cycle action.

This patch continues the process of setting up build-many-glibcs.py to
run as a bot monitoring for and reporting on build issues by adding a
bot-cycle action to the script.  When this action is used, it will run
the checkout action (re-execing itself if it was changed by that
action), then rebuild whichever of host-libraries, compilers, glibcs
should be rebuilt based on changed versions, time elapsed and state of
previous builds.  Email is sent with the results of the build (for
each build action done).

The rebuild logic is: if previous build time or versions aren't
recorded, rebuild that component.  If the script has changed, rebuild
everything.  If any relevant component version has changed, rebuild,
except for not rebuilding compilers if the time indicated in the bot
configuration has not passed since the last build of the compilers.
If one piece is rebuilt then rebuild subsequent pieces as well.

Using bot-cycle requires a configuration file bot-config.json in the
toplevel directory used by build-many-glibcs.py.  It might contain
e.g.

{
  "compilers-rebuild-delay": 604800,
  "email-from": "Example Name <user@example.org>",
  "email-server": "localhost",
  "email-subject": "GCC 6 %(action)s %(build-time)s build results",
  "email-to": "libc-testresults@sourceware.org"
}

My next intended step is adding a further action "bot" which loops
running bot-cycle then sleeping for an amount of time given in
bot-config.json.  Then I'll set up a bot using that action (building
with GCC 6 branch; a bot using GCC mainline may wait until the SH
out-of-memory issues
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78460> are fixed; I
expect the bot to mail to me until it seems ready to switch to mailing
to gcc-testresults).

	* scripts/build-many-glibcs.py: Add bot-cycle to usage message.
	Import email.mime.text, email.utils and smtplib modules.
	(Context.__init__): Initialize self.bot_config_json.
	(Context.run_builds): Handle bot-cycle action.
	(Context.load_bot_config_json): New function.
	(Context.part_build_old): Likewise.
	(Context.bot_cycle): Likewise.
	(Context.bot_build_mail): Likewise.
	(Context.bot_run_self): Likewise.
	(get_parser): Allow bot-cycle action.

ChangeLog

@@ -1,3 +1,16 @@
+2016-11-30  Joseph Myers  <joseph@codesourcery.com>
+
+	* scripts/build-many-glibcs.py: Add bot-cycle to usage message.
+	Import email.mime.text, email.utils and smtplib modules.
+	(Context.__init__): Initialize self.bot_config_json.
+	(Context.run_builds): Handle bot-cycle action.
+	(Context.load_bot_config_json): New function.
+	(Context.part_build_old): Likewise.
+	(Context.bot_cycle): Likewise.
+	(Context.bot_build_mail): Likewise.
+	(Context.bot_run_self): Likewise.
+	(get_parser): Allow bot-cycle action.
+
 2016-11-30  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
 	* sysdeps/powerpc/powerpc64/multiarch/stpcpy-ppc64.c (weak_alias):

scripts/build-many-glibcs.py

@@ -22,21 +22,26 @@
 This script takes as arguments a directory name (containing a src
 subdirectory with sources of the relevant toolchain components) and a
 description of what to do: 'checkout', to check out sources into that
-directory, 'host-libraries', to build libraries required by the
+directory, 'bot-cycle', to run a series of checkout and build steps,
-toolchain, 'compilers', to build cross-compilers for various
+'host-libraries', to build libraries required by the toolchain,
-configurations, or 'glibcs', to build glibc for various configurations
+'compilers', to build cross-compilers for various configurations, or
-and run the compilation parts of the testsuite.  Subsequent arguments
+'glibcs', to build glibc for various configurations and run the
-name the versions of components to check out (<component>-<version),
+compilation parts of the testsuite.  Subsequent arguments name the
-for 'checkout', or, for actions other than 'checkout', name
+versions of components to check out (<component>-<version), for
-configurations for which compilers or glibc are to be built.
+'checkout', or, for actions other than 'checkout' and 'bot-cycle',
+name configurations for which compilers or glibc are to be built.
+
 """
 
 import argparse
 import datetime
+import email.mime.text
+import email.utils
 import json
 import os
 import re
 import shutil
+import smtplib
 import stat
 import subprocess
 import sys
@@ -55,6 +60,7 @@ class Context(object):
         self.srcdir = os.path.join(topdir, 'src')
         self.versions_json = os.path.join(self.srcdir, 'versions.json')
         self.build_state_json = os.path.join(topdir, 'build-state.json')
+        self.bot_config_json = os.path.join(topdir, 'bot-config.json')
         self.installdir = os.path.join(topdir, 'install')
         self.host_libraries_installdir = os.path.join(self.installdir,
                                                       'host-libraries')
@@ -392,6 +398,12 @@ class Context(object):
         if action == 'checkout':
             self.checkout(configs)
             return
+        if action == 'bot-cycle':
+            if configs:
+                print('error: configurations specified for bot-cycle')
+                exit(1)
+            self.bot_cycle()
+            return
         if action == 'host-libraries' and configs:
             print('error: configurations specified for host-libraries')
             exit(1)
@@ -860,6 +872,146 @@ class Context(object):
                                                          new_passes)
         self.store_build_state_json()
 
+    def load_bot_config_json(self):
+        """Load bot configuration."""
+        with open(self.bot_config_json, 'r') as f:
+            self.bot_config = json.load(f)
+
+    def part_build_old(self, action, delay):
+        """Return whether the last build for a given action was at least a
+        given number of seconds ago, or does not have a time recorded."""
+        old_time_str = self.build_state[action]['build-time']
+        if not old_time_str:
+            return True
+        old_time = datetime.datetime.strptime(old_time_str,
+                                              '%Y-%m-%d %H:%M:%S')
+        new_time = datetime.datetime.utcnow()
+        delta = new_time - old_time
+        return delta.total_seconds() >= delay
+
+    def bot_cycle(self):
+        """Run a single round of checkout and builds."""
+        print('Bot cycle starting %s.' % str(datetime.datetime.utcnow()))
+        self.load_bot_config_json()
+        actions = ('host-libraries', 'compilers', 'glibcs')
+        self.bot_run_self(['--replace-sources'], 'checkout')
+        self.load_versions_json()
+        if self.get_script_text() != self.script_text:
+            print('Script changed, re-execing.')
+            # On script change, all parts of the build should be rerun.
+            for a in actions:
+                self.clear_last_build_state(a)
+            self.exec_self()
+        check_components = {'host-libraries': ('gmp', 'mpfr', 'mpc'),
+                            'compilers': ('binutils', 'gcc', 'glibc', 'linux'),
+                            'glibcs': ('glibc',)}
+        must_build = {}
+        for a in actions:
+            build_vers = self.build_state[a]['build-versions']
+            must_build[a] = False
+            if not self.build_state[a]['build-time']:
+                must_build[a] = True
+            old_vers = {}
+            new_vers = {}
+            for c in check_components[a]:
+                if c in build_vers:
+                    old_vers[c] = build_vers[c]
+                new_vers[c] = {'version': self.versions[c]['version'],
+                               'revision': self.versions[c]['revision']}
+            if new_vers == old_vers:
+                print('Versions for %s unchanged.' % a)
+            else:
+                print('Versions changed or rebuild forced for %s.' % a)
+                if a == 'compilers' and not self.part_build_old(
+                        a, self.bot_config['compilers-rebuild-delay']):
+                    print('Not requiring rebuild of compilers this soon.')
+                else:
+                    must_build[a] = True
+        if must_build['host-libraries']:
+            must_build['compilers'] = True
+        if must_build['compilers']:
+            must_build['glibcs'] = True
+        for a in actions:
+            if must_build[a]:
+                print('Must rebuild %s.' % a)
+                self.clear_last_build_state(a)
+            else:
+                print('No need to rebuild %s.' % a)
+        for a in actions:
+            if must_build[a]:
+                build_time = datetime.datetime.utcnow()
+                print('Rebuilding %s at %s.' % (a, str(build_time)))
+                self.bot_run_self([], a)
+                self.load_build_state_json()
+                self.bot_build_mail(a, build_time)
+        print('Bot cycle done at %s.' % str(datetime.datetime.utcnow()))
+
+    def bot_build_mail(self, action, build_time):
+        """Send email with the results of a build."""
+        build_time = build_time.replace(microsecond=0)
+        subject = (self.bot_config['email-subject'] %
+                   {'action': action,
+                    'build-time': str(build_time)})
+        results = self.build_state[action]['build-results']
+        changes = self.build_state[action]['result-changes']
+        ever_passed = set(self.build_state[action]['ever-passed'])
+        versions = self.build_state[action]['build-versions']
+        new_regressions = {k for k in changes if changes[k] == 'PASS -> FAIL'}
+        all_regressions = {k for k in ever_passed if results[k] == 'FAIL'}
+        all_fails = {k for k in results if results[k] == 'FAIL'}
+        if new_regressions:
+            new_reg_list = sorted(['FAIL: %s' % k for k in new_regressions])
+            new_reg_text = ('New regressions:\n\n%s\n\n' %
+                            '\n'.join(new_reg_list))
+        else:
+            new_reg_text = ''
+        if all_regressions:
+            all_reg_list = sorted(['FAIL: %s' % k for k in all_regressions])
+            all_reg_text = ('All regressions:\n\n%s\n\n' %
+                            '\n'.join(all_reg_list))
+        else:
+            all_reg_text = ''
+        if all_fails:
+            all_fail_list = sorted(['FAIL: %s' % k for k in all_fails])
+            all_fail_text = ('All failures:\n\n%s\n\n' %
+                             '\n'.join(all_fail_list))
+        else:
+            all_fail_text = ''
+        if changes:
+            changes_list = sorted(changes.keys())
+            changes_list = ['%s: %s' % (changes[k], k) for k in changes_list]
+            changes_text = ('All changed results:\n\n%s\n\n' %
+                            '\n'.join(changes_list))
+        else:
+            changes_text = ''
+        results_text = (new_reg_text + all_reg_text + all_fail_text +
+                        changes_text)
+        if not results_text:
+            results_text = 'Clean build with unchanged results.\n\n'
+        versions_list = sorted(versions.keys())
+        versions_list = ['%s: %s (%s)' % (k, versions[k]['version'],
+                                          versions[k]['revision'])
+                         for k in versions_list]
+        versions_text = ('Component versions for this build:\n\n%s\n' %
+                         '\n'.join(versions_list))
+        body_text = results_text + versions_text
+        msg = email.mime.text.MIMEText(body_text)
+        msg['Subject'] = subject
+        msg['From'] = self.bot_config['email-from']
+        msg['To'] = self.bot_config['email-to']
+        msg['Message-ID'] = email.utils.make_msgid()
+        msg['Date'] = email.utils.format_datetime(datetime.datetime.utcnow())
+        with smtplib.SMTP(self.bot_config['email-server']) as s:
+            s.send_message(msg)
+
+    def bot_run_self(self, opts, action):
+        """Run a copy of this script with given options."""
+        cmd = [sys.executable, sys.argv[0], '--keep=none',
+               '-j%d' % self.parallelism]
+        cmd.extend(opts)
+        cmd.extend([self.topdir, action])
+        subprocess.run(cmd, check=True)
+
 
 class Config(object):
     """A configuration for building a compiler and associated libraries."""
@@ -1312,8 +1464,8 @@ def get_parser():
                         help='Toplevel working directory')
     parser.add_argument('action',
                         help='What to do',
-                        choices=('checkout', 'host-libraries', 'compilers',
+                        choices=('checkout', 'bot-cycle', 'host-libraries',
-                                 'glibcs'))
+                                 'compilers', 'glibcs'))
     parser.add_argument('configs',
                         help='Versions to check out or configurations to build',
                         nargs='*')