buildman - U-Boot multi-threaded builder and summary tool

This tool handles building U-Boot to check that you have not broken it
with your patch series. It can build each individual commit and report
which boards fail on which commits, and which errors come up. It also
shows differences in image sizes due to particular commits.

Buildman aims to make full use of multi-processor machines.

Documentation and caveats are in tools/buildman/README.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 1445 insertions, 0 deletions

diff --git a/tools/buildman/builder.py b/tools/buildman/builder.py
new file mode 100644
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+++ b/tools/buildman/builder.py
@@ -0,0 +1,1445 @@
+# Copyright (c) 2013 The Chromium OS Authors.
+#
+# Bloat-o-meter code used here Copyright 2004 Matt Mackall <mpm@selenic.com>
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+import collections
+import errno
+from datetime import datetime, timedelta
+import glob
+import os
+import re
+import Queue
+import shutil
+import string
+import sys
+import threading
+import time
+
+import command
+import gitutil
+import terminal
+import toolchain
+
+
+"""
+Theory of Operation
+
+Please see README for user documentation, and you should be familiar with
+that before trying to make sense of this.
+
+Buildman works by keeping the machine as busy as possible, building different
+commits for different boards on multiple CPUs at once.
+
+The source repo (self.git_dir) contains all the commits to be built. Each
+thread works on a single board at a time. It checks out the first commit,
+configures it for that board, then builds it. Then it checks out the next
+commit and builds it (typically without re-configuring). When it runs out
+of commits, it gets another job from the builder and starts again with that
+board.
+
+Clearly the builder threads could work either way - they could check out a
+commit and then built it for all boards. Using separate directories for each
+commit/board pair they could leave their build product around afterwards
+also.
+
+The intent behind building a single board for multiple commits, is to make
+use of incremental builds. Since each commit is built incrementally from
+the previous one, builds are faster. Reconfiguring for a different board
+removes all intermediate object files.
+
+Many threads can be working at once, but each has its own working directory.
+When a thread finishes a build, it puts the output files into a result
+directory.
+
+The base directory used by buildman is normally '../<branch>', i.e.
+a directory higher than the source repository and named after the branch
+being built.
+
+Within the base directory, we have one subdirectory for each commit. Within
+that is one subdirectory for each board. Within that is the build output for
+that commit/board combination.
+
+Buildman also create working directories for each thread, in a .bm-work/
+subdirectory in the base dir.
+
+As an example, say we are building branch 'us-net' for boards 'sandbox' and
+'seaboard', and say that us-net has two commits. We will have directories
+like this:
+
+us-net/             base directory
+    01_of_02_g4ed4ebc_net--Add-tftp-speed-/
+        sandbox/
+            u-boot.bin
+        seaboard/
+            u-boot.bin
+    02_of_02_g4ed4ebc_net--Check-tftp-comp/
+        sandbox/
+            u-boot.bin
+        seaboard/
+            u-boot.bin
+    .bm-work/
+        00/         working directory for thread 0 (contains source checkout)
+            build/  build output
+        01/         working directory for thread 1
+            build/  build output
+        ...
+u-boot/             source directory
+    .git/           repository
+"""
+
+# Possible build outcomes
+OUTCOME_OK, OUTCOME_WARNING, OUTCOME_ERROR, OUTCOME_UNKNOWN = range(4)
+
+# Translate a commit subject into a valid filename
+trans_valid_chars = string.maketrans("/: ", "---")
+
+
+def Mkdir(dirname):
+    """Make a directory if it doesn't already exist.
+
+    Args:
+        dirname: Directory to create
+    """
+    try:
+        os.mkdir(dirname)
+    except OSError as err:
+        if err.errno == errno.EEXIST:
+            pass
+        else:
+            raise
+
+class BuilderJob:
+    """Holds information about a job to be performed by a thread
+
+    Members:
+        board: Board object to build
+        commits: List of commit options to build.
+    """
+    def __init__(self):
+        self.board = None
+        self.commits = []
+
+
+class ResultThread(threading.Thread):
+    """This thread processes results from builder threads.
+
+    It simply passes the results on to the builder. There is only one
+    result thread, and this helps to serialise the build output.
+    """
+    def __init__(self, builder):
+        """Set up a new result thread
+
+        Args:
+            builder: Builder which will be sent each result
+        """
+        threading.Thread.__init__(self)
+        self.builder = builder
+
+    def run(self):
+        """Called to start up the result thread.
+
+        We collect the next result job and pass it on to the build.
+        """
+        while True:
+            result = self.builder.out_queue.get()
+            self.builder.ProcessResult(result)
+            self.builder.out_queue.task_done()
+
+
+class BuilderThread(threading.Thread):
+    """This thread builds U-Boot for a particular board.
+
+    An input queue provides each new job. We run 'make' to build U-Boot
+    and then pass the results on to the output queue.
+
+    Members:
+        builder: The builder which contains information we might need
+        thread_num: Our thread number (0-n-1), used to decide on a
+                temporary directory
+    """
+    def __init__(self, builder, thread_num):
+        """Set up a new builder thread"""
+        threading.Thread.__init__(self)
+        self.builder = builder
+        self.thread_num = thread_num
+
+    def Make(self, commit, brd, stage, cwd, *args, **kwargs):
+        """Run 'make' on a particular commit and board.
+
+        The source code will already be checked out, so the 'commit'
+        argument is only for information.
+
+        Args:
+            commit: Commit object that is being built
+            brd: Board object that is being built
+            stage: Stage of the build. Valid stages are:
+                        distclean - can be called to clean source
+                        config - called to configure for a board
+                        build - the main make invocation - it does the build
+            args: A list of arguments to pass to 'make'
+            kwargs: A list of keyword arguments to pass to command.RunPipe()
+
+        Returns:
+            CommandResult object
+        """
+        return self.builder.do_make(commit, brd, stage, cwd, *args,
+                **kwargs)
+
+    def RunCommit(self, commit_upto, brd, work_dir, do_config, force_build):
+        """Build a particular commit.
+
+        If the build is already done, and we are not forcing a build, we skip
+        the build and just return the previously-saved results.
+
+        Args:
+            commit_upto: Commit number to build (0...n-1)
+            brd: Board object to build
+            work_dir: Directory to which the source will be checked out
+            do_config: True to run a make <board>_config on the source
+            force_build: Force a build even if one was previously done
+
+        Returns:
+            tuple containing:
+                - CommandResult object containing the results of the build
+                - boolean indicating whether 'make config' is still needed
+        """
+        # Create a default result - it will be overwritte by the call to
+        # self.Make() below, in the event that we do a build.
+        result = command.CommandResult()
+        result.return_code = 0
+        out_dir = os.path.join(work_dir, 'build')
+
+        # Check if the job was already completed last time
+        done_file = self.builder.GetDoneFile(commit_upto, brd.target)
+        result.already_done = os.path.exists(done_file)
+        if result.already_done and not force_build:
+            # Get the return code from that build and use it
+            with open(done_file, 'r') as fd:
+                result.return_code = int(fd.readline())
+            err_file = self.builder.GetErrFile(commit_upto, brd.target)
+            if os.path.exists(err_file) and os.stat(err_file).st_size:
+                result.stderr = 'bad'
+        else:
+            # We are going to have to build it. First, get a toolchain
+            if not self.toolchain:
+                try:
+                    self.toolchain = self.builder.toolchains.Select(brd.arch)
+                except ValueError as err:
+                    result.return_code = 10
+                    result.stdout = ''
+                    result.stderr = str(err)
+                    # TODO(sjg@chromium.org): This gets swallowed, but needs
+                    # to be reported.
+
+            if self.toolchain:
+                # Checkout the right commit
+                if commit_upto is not None:
+                    commit = self.builder.commits[commit_upto]
+                    if self.builder.checkout:
+                        git_dir = os.path.join(work_dir, '.git')
+                        gitutil.Checkout(commit.hash, git_dir, work_dir,
+                                         force=True)
+                else:
+                    commit = self.builder.commit # Ick, fix this for BuildCommits()
+
+                # Set up the environment and command line
+                env = self.toolchain.MakeEnvironment()
+                Mkdir(out_dir)
+                args = ['O=build', '-s']
+                if self.builder.num_jobs is not None:
+                    args.extend(['-j', str(self.builder.num_jobs)])
+                config_args = ['%s_config' % brd.target]
+                config_out = ''
+
+                # If we need to reconfigure, do that now
+                if do_config:
+                    result = self.Make(commit, brd, 'distclean', work_dir,
+                            'distclean', *args, env=env)
+                    result = self.Make(commit, brd, 'config', work_dir,
+                            *(args + config_args), env=env)
+                    config_out = result.combined
+                    do_config = False   # No need to configure next time
+                if result.return_code == 0:
+                    result = self.Make(commit, brd, 'build', work_dir, *args,
+                            env=env)
+                    result.stdout = config_out + result.stdout
+            else:
+                result.return_code = 1
+                result.stderr = 'No tool chain for %s\n' % brd.arch
+            result.already_done = False
+
+        result.toolchain = self.toolchain
+        result.brd = brd
+        result.commit_upto = commit_upto
+        result.out_dir = out_dir
+        return result, do_config
+
+    def _WriteResult(self, result, keep_outputs):
+        """Write a built result to the output directory.
+
+        Args:
+            result: CommandResult object containing result to write
+            keep_outputs: True to store the output binaries, False
+                to delete them
+        """
+        # Fatal error
+        if result.return_code < 0:
+            return
+
+        # Aborted?
+        if result.stderr and 'No child processes' in result.stderr:
+            return
+
+        if result.already_done:
+            return
+
+        # Write the output and stderr
+        output_dir = self.builder._GetOutputDir(result.commit_upto)
+        Mkdir(output_dir)
+        build_dir = self.builder.GetBuildDir(result.commit_upto,
+                result.brd.target)
+        Mkdir(build_dir)
+
+        outfile = os.path.join(build_dir, 'log')
+        with open(outfile, 'w') as fd:
+            if result.stdout:
+                fd.write(result.stdout)
+
+        errfile = self.builder.GetErrFile(result.commit_upto,
+                result.brd.target)
+        if result.stderr:
+            with open(errfile, 'w') as fd:
+                fd.write(result.stderr)
+        elif os.path.exists(errfile):
+            os.remove(errfile)
+
+        if result.toolchain:
+            # Write the build result and toolchain information.
+            done_file = self.builder.GetDoneFile(result.commit_upto,
+                    result.brd.target)
+            with open(done_file, 'w') as fd:
+                fd.write('%s' % result.return_code)
+            with open(os.path.join(build_dir, 'toolchain'), 'w') as fd:
+                print >>fd, 'gcc', result.toolchain.gcc
+                print >>fd, 'path', result.toolchain.path
+                print >>fd, 'cross', result.toolchain.cross
+                print >>fd, 'arch', result.toolchain.arch
+                fd.write('%s' % result.return_code)
+
+            with open(os.path.join(build_dir, 'toolchain'), 'w') as fd:
+                print >>fd, 'gcc', result.toolchain.gcc
+                print >>fd, 'path', result.toolchain.path
+
+            # Write out the image and function size information and an objdump
+            env = result.toolchain.MakeEnvironment()
+            lines = []
+            for fname in ['u-boot', 'spl/u-boot-spl']:
+                cmd = ['%snm' % self.toolchain.cross, '--size-sort', fname]
+                nm_result = command.RunPipe([cmd], capture=True,
+                        capture_stderr=True, cwd=result.out_dir,
+                        raise_on_error=False, env=env)
+                if nm_result.stdout:
+                    nm = self.builder.GetFuncSizesFile(result.commit_upto,
+                                    result.brd.target, fname)
+                    with open(nm, 'w') as fd:
+                        print >>fd, nm_result.stdout,
+
+                cmd = ['%sobjdump' % self.toolchain.cross, '-h', fname]
+                dump_result = command.RunPipe([cmd], capture=True,
+                        capture_stderr=True, cwd=result.out_dir,
+                        raise_on_error=False, env=env)
+                rodata_size = ''
+                if dump_result.stdout:
+                    objdump = self.builder.GetObjdumpFile(result.commit_upto,
+                                    result.brd.target, fname)
+                    with open(objdump, 'w') as fd:
+                        print >>fd, dump_result.stdout,
+                    for line in dump_result.stdout.splitlines():
+                        fields = line.split()
+                        if len(fields) > 5 and fields[1] == '.rodata':
+                            rodata_size = fields[2]
+
+                cmd = ['%ssize' % self.toolchain.cross, fname]
+                size_result = command.RunPipe([cmd], capture=True,
+                        capture_stderr=True, cwd=result.out_dir,
+                        raise_on_error=False, env=env)
+                if size_result.stdout:
+                    lines.append(size_result.stdout.splitlines()[1] + ' ' +
+                                 rodata_size)
+
+            # Write out the image sizes file. This is similar to the output
+            # of binutil's 'size' utility, but it omits the header line and
+            # adds an additional hex value at the end of each line for the
+            # rodata size
+            if len(lines):
+                sizes = self.builder.GetSizesFile(result.commit_upto,
+                                result.brd.target)
+                with open(sizes, 'w') as fd:
+                    print >>fd, '\n'.join(lines)
+
+        # Now write the actual build output
+        if keep_outputs:
+            patterns = ['u-boot', '*.bin', 'u-boot.dtb', '*.map',
+                        'include/autoconf.mk', 'spl/u-boot-spl',
+                        'spl/u-boot-spl.bin']
+            for pattern in patterns:
+                file_list = glob.glob(os.path.join(result.out_dir, pattern))
+                for fname in file_list:
+                    shutil.copy(fname, build_dir)
+
+
+    def RunJob(self, job):
+        """Run a single job
+
+        A job consists of a building a list of commits for a particular board.
+
+        Args:
+            job: Job to build
+        """
+        brd = job.board
+        work_dir = self.builder.GetThreadDir(self.thread_num)
+        self.toolchain = None
+        if job.commits:
+            # Run 'make board_config' on the first commit
+            do_config = True
+            commit_upto  = 0
+            force_build = False
+            for commit_upto in range(0, len(job.commits), job.step):
+                result, request_config = self.RunCommit(commit_upto, brd,
+                        work_dir, do_config,
+                        force_build or self.builder.force_build)
+                failed = result.return_code or result.stderr
+                if failed and not do_config:
+                    # If our incremental build failed, try building again
+                    # with a reconfig.
+                    if self.builder.force_config_on_failure:
+                        result, request_config = self.RunCommit(commit_upto,
+                            brd, work_dir, True, True)
+                do_config = request_config
+
+                # If we built that commit, then config is done. But if we got
+                # an warning, reconfig next time to force it to build the same
+                # files that created warnings this time. Otherwise an
+                # incremental build may not build the same file, and we will
+                # think that the warning has gone away.
+                # We could avoid this by using -Werror everywhere...
+                # For errors, the problem doesn't happen, since presumably
+                # the build stopped and didn't generate output, so will retry
+                # that file next time. So we could detect warnings and deal
+                # with them specially here. For now, we just reconfigure if
+                # anything goes work.
+                # Of course this is substantially slower if there are build
+                # errors/warnings (e.g. 2-3x slower even if only 10% of builds
+                # have problems).
+                if (failed and not result.already_done and not do_config and
+                        self.builder.force_config_on_failure):
+                    # If this build failed, try the next one with a
+                    # reconfigure.
+                    # Sometimes if the board_config.h file changes it can mess
+                    # with dependencies, and we get:
+                    # make: *** No rule to make target `include/autoconf.mk',
+                    #     needed by `depend'.
+                    do_config = True
+                    force_build = True
+                else:
+                    force_build = False
+                    if self.builder.force_config_on_failure:
+                        if failed:
+                            do_config = True
+                    result.commit_upto = commit_upto
+                    if result.return_code < 0:
+                        raise ValueError('Interrupt')
+
+                # We have the build results, so output the result
+                self._WriteResult(result, job.keep_outputs)
+                self.builder.out_queue.put(result)
+        else:
+            # Just build the currently checked-out build
+            result = self.RunCommit(None, True)
+            result.commit_upto = self.builder.upto
+            self.builder.out_queue.put(result)
+
+    def run(self):
+        """Our thread's run function
+
+        This thread picks a job from the queue, runs it, and then goes to the
+        next job.
+        """
+        alive = True
+        while True:
+            job = self.builder.queue.get()
+            try:
+                if self.builder.active and alive:
+                    self.RunJob(job)
+            except Exception as err:
+                alive = False
+                print err
+            self.builder.queue.task_done()
+
+
+class Builder:
+    """Class for building U-Boot for a particular commit.
+
+    Public members: (many should ->private)
+        active: True if the builder is active and has not been stopped
+        already_done: Number of builds already completed
+        base_dir: Base directory to use for builder
+        checkout: True to check out source, False to skip that step.
+            This is used for testing.
+        col: terminal.Color() object
+        count: Number of commits to build
+        do_make: Method to call to invoke Make
+        fail: Number of builds that failed due to error
+        force_build: Force building even if a build already exists
+        force_config_on_failure: If a commit fails for a board, disable
+            incremental building for the next commit we build for that
+            board, so that we will see all warnings/errors again.
+        git_dir: Git directory containing source repository
+        last_line_len: Length of the last line we printed (used for erasing
+            it with new progress information)
+        num_jobs: Number of jobs to run at once (passed to make as -j)
+        num_threads: Number of builder threads to run
+        out_queue: Queue of results to process
+        re_make_err: Compiled regular expression for ignore_lines
+        queue: Queue of jobs to run
+        threads: List of active threads
+        toolchains: Toolchains object to use for building
+        upto: Current commit number we are building (0.count-1)
+        warned: Number of builds that produced at least one warning
+
+    Private members:
+        _base_board_dict: Last-summarised Dict of boards
+        _base_err_lines: Last-summarised list of errors
+        _build_period_us: Time taken for a single build (float object).
+        _complete_delay: Expected delay until completion (timedelta)
+        _next_delay_update: Next time we plan to display a progress update
+                (datatime)
+        _show_unknown: Show unknown boards (those not built) in summary
+        _timestamps: List of timestamps for the completion of the last
+            last _timestamp_count builds. Each is a datetime object.
+        _timestamp_count: Number of timestamps to keep in our list.
+        _working_dir: Base working directory containing all threads
+    """
+    class Outcome:
+        """Records a build outcome for a single make invocation
+
+        Public Members:
+            rc: Outcome value (OUTCOME_...)
+            err_lines: List of error lines or [] if none
+            sizes: Dictionary of image size information, keyed by filename
+                - Each value is itself a dictionary containing
+                    values for 'text', 'data' and 'bss', being the integer
+                    size in bytes of each section.
+            func_sizes: Dictionary keyed by filename - e.g. 'u-boot'. Each
+                    value is itself a dictionary:
+                        key: function name
+                        value: Size of function in bytes
+        """
+        def __init__(self, rc, err_lines, sizes, func_sizes):
+            self.rc = rc
+            self.err_lines = err_lines
+            self.sizes = sizes
+            self.func_sizes = func_sizes
+
+    def __init__(self, toolchains, base_dir, git_dir, num_threads, num_jobs,
+                 checkout=True, show_unknown=True, step=1):
+        """Create a new Builder object
+
+        Args:
+            toolchains: Toolchains object to use for building
+            base_dir: Base directory to use for builder
+            git_dir: Git directory containing source repository
+            num_threads: Number of builder threads to run
+            num_jobs: Number of jobs to run at once (passed to make as -j)
+            checkout: True to check out source, False to skip that step.
+                This is used for testing.
+            show_unknown: Show unknown boards (those not built) in summary
+            step: 1 to process every commit, n to process every nth commit
+        """
+        self.toolchains = toolchains
+        self.base_dir = base_dir
+        self._working_dir = os.path.join(base_dir, '.bm-work')
+        self.threads = []
+        self.active = True
+        self.do_make = self.Make
+        self.checkout = checkout
+        self.num_threads = num_threads
+        self.num_jobs = num_jobs
+        self.already_done = 0
+        self.force_build = False
+        self.git_dir = git_dir
+        self._show_unknown = show_unknown
+        self._timestamp_count = 10
+        self._build_period_us = None
+        self._complete_delay = None
+        self._next_delay_update = datetime.now()
+        self.force_config_on_failure = True
+        self._step = step
+
+        self.col = terminal.Color()
+
+        self.queue = Queue.Queue()
+        self.out_queue = Queue.Queue()
+        for i in range(self.num_threads):
+            t = BuilderThread(self, i)
+            t.setDaemon(True)
+            t.start()
+            self.threads.append(t)
+
+        self.last_line_len = 0
+        t = ResultThread(self)
+        t.setDaemon(True)
+        t.start()
+        self.threads.append(t)
+
+        ignore_lines = ['(make.*Waiting for unfinished)', '(Segmentation fault)']
+        self.re_make_err = re.compile('|'.join(ignore_lines))
+
+    def __del__(self):
+        """Get rid of all threads created by the builder"""
+        for t in self.threads:
+            del t
+
+    def _AddTimestamp(self):
+        """Add a new timestamp to the list and record the build period.
+
+        The build period is the length of time taken to perform a single
+        build (one board, one commit).
+        """
+        now = datetime.now()
+        self._timestamps.append(now)
+        count = len(self._timestamps)
+        delta = self._timestamps[-1] - self._timestamps[0]
+        seconds = delta.total_seconds()
+
+        # If we have enough data, estimate build period (time taken for a
+        # single build) and therefore completion time.
+        if count > 1 and self._next_delay_update < now:
+            self._next_delay_update = now + timedelta(seconds=2)
+            if seconds > 0:
+                self._build_period = float(seconds) / count
+                todo = self.count - self.upto
+                self._complete_delay = timedelta(microseconds=
+                        self._build_period * todo * 1000000)
+                # Round it
+                self._complete_delay -= timedelta(
+                        microseconds=self._complete_delay.microseconds)
+
+        if seconds > 60:
+            self._timestamps.popleft()
+            count -= 1
+
+    def ClearLine(self, length):
+        """Clear any characters on the current line
+
+        Make way for a new line of length 'length', by outputting enough
+        spaces to clear out the old line. Then remember the new length for
+        next time.
+
+        Args:
+            length: Length of new line, in characters
+        """
+        if length < self.last_line_len:
+            print ' ' * (self.last_line_len - length),
+            print '\r',
+        self.last_line_len = length
+        sys.stdout.flush()
+
+    def SelectCommit(self, commit, checkout=True):
+        """Checkout the selected commit for this build
+        """
+        self.commit = commit
+        if checkout and self.checkout:
+            gitutil.Checkout(commit.hash)
+
+    def Make(self, commit, brd, stage, cwd, *args, **kwargs):
+        """Run make
+
+        Args:
+            commit: Commit object that is being built
+            brd: Board object that is being built
+            stage: Stage that we are at (distclean, config, build)
+            cwd: Directory where make should be run
+            args: Arguments to pass to make
+            kwargs: Arguments to pass to command.RunPipe()
+        """
+        cmd = ['make'] + list(args)
+        result = command.RunPipe([cmd], capture=True, capture_stderr=True,
+                cwd=cwd, raise_on_error=False, **kwargs)
+        return result
+
+    def ProcessResult(self, result):
+        """Process the result of a build, showing progress information
+
+        Args:
+            result: A CommandResult object
+        """
+        col = terminal.Color()
+        if result:
+            target = result.brd.target
+
+            if result.return_code < 0:
+                self.active = False
+                command.StopAll()
+                return
+
+            self.upto += 1
+            if result.return_code != 0:
+                self.fail += 1
+            elif result.stderr:
+                self.warned += 1
+            if result.already_done:
+                self.already_done += 1
+        else:
+            target = '(starting)'
+
+        # Display separate counts for ok, warned and fail
+        ok = self.upto - self.warned - self.fail
+        line = '\r' + self.col.Color(self.col.GREEN, '%5d' % ok)
+        line += self.col.Color(self.col.YELLOW, '%5d' % self.warned)
+        line += self.col.Color(self.col.RED, '%5d' % self.fail)
+
+        name = ' /%-5d  ' % self.count
+
+        # Add our current completion time estimate
+        self._AddTimestamp()
+        if self._complete_delay:
+            name += '%s  : ' % self._complete_delay
+        # When building all boards for a commit, we can print a commit
+        # progress message.
+        if result and result.commit_upto is None:
+            name += 'commit %2d/%-3d' % (self.commit_upto + 1,
+                    self.commit_count)
+
+        name += target
+        print line + name,
+        length = 13 + len(name)
+        self.ClearLine(length)
+
+    def _GetOutputDir(self, commit_upto):
+        """Get the name of the output directory for a commit number
+
+        The output directory is typically .../<branch>/<commit>.
+
+        Args:
+            commit_upto: Commit number to use (0..self.count-1)
+        """
+        commit = self.commits[commit_upto]
+        subject = commit.subject.translate(trans_valid_chars)
+        commit_dir = ('%02d_of_%02d_g%s_%s' % (commit_upto + 1,
+                self.commit_count, commit.hash, subject[:20]))
+        output_dir = os.path.join(self.base_dir, commit_dir)
+        return output_dir
+
+    def GetBuildDir(self, commit_upto, target):
+        """Get the name of the build directory for a commit number
+
+        The build directory is typically .../<branch>/<commit>/<target>.
+
+        Args:
+            commit_upto: Commit number to use (0..self.count-1)
+            target: Target name
+        """
+        output_dir = self._GetOutputDir(commit_upto)
+        return os.path.join(output_dir, target)
+
+    def GetDoneFile(self, commit_upto, target):
+        """Get the name of the done file for a commit number
+
+        Args:
+            commit_upto: Commit number to use (0..self.count-1)
+            target: Target name
+        """
+        return os.path.join(self.GetBuildDir(commit_upto, target), 'done')
+
+    def GetSizesFile(self, commit_upto, target):
+        """Get the name of the sizes file for a commit number
+
+        Args:
+            commit_upto: Commit number to use (0..self.count-1)
+            target: Target name
+        """
+        return os.path.join(self.GetBuildDir(commit_upto, target), 'sizes')
+
+    def GetFuncSizesFile(self, commit_upto, target, elf_fname):
+        """Get the name of the funcsizes file for a commit number and ELF file
+
+        Args:
+            commit_upto: Commit number to use (0..self.count-1)
+            target: Target name
+            elf_fname: Filename of elf image
+        """
+        return os.path.join(self.GetBuildDir(commit_upto, target),
+                            '%s.sizes' % elf_fname.replace('/', '-'))
+
+    def GetObjdumpFile(self, commit_upto, target, elf_fname):
+        """Get the name of the objdump file for a commit number and ELF file
+
+        Args:
+            commit_upto: Commit number to use (0..self.count-1)
+            target: Target name
+            elf_fname: Filename of elf image
+        """
+        return os.path.join(self.GetBuildDir(commit_upto, target),
+                            '%s.objdump' % elf_fname.replace('/', '-'))
+
+    def GetErrFile(self, commit_upto, target):
+        """Get the name of the err file for a commit number
+
+        Args:
+            commit_upto: Commit number to use (0..self.count-1)
+            target: Target name
+        """
+        output_dir = self.GetBuildDir(commit_upto, target)
+        return os.path.join(output_dir, 'err')
+
+    def FilterErrors(self, lines):
+        """Filter out errors in which we have no interest
+
+        We should probably use map().
+
+        Args:
+            lines: List of error lines, each a string
+        Returns:
+            New list with only interesting lines included
+        """
+        out_lines = []
+        for line in lines:
+            if not self.re_make_err.search(line):
+                out_lines.append(line)
+        return out_lines
+
+    def ReadFuncSizes(self, fname, fd):
+        """Read function sizes from the output of 'nm'
+
+        Args:
+            fd: File containing data to read
+            fname: Filename we are reading from (just for errors)
+
+        Returns:
+            Dictionary containing size of each function in bytes, indexed by
+            function name.
+        """
+        sym = {}
+        for line in fd.readlines():
+            try:
+                size, type, name = line[:-1].split()
+            except:
+                print "Invalid line in file '%s': '%s'" % (fname, line[:-1])
+                continue
+            if type in 'tTdDbB':
+                # function names begin with '.' on 64-bit powerpc
+                if '.' in name[1:]:
+                    name = 'static.' + name.split('.')[0]
+                sym[name] = sym.get(name, 0) + int(size, 16)
+        return sym
+
+    def GetBuildOutcome(self, commit_upto, target, read_func_sizes):
+        """Work out the outcome of a build.
+
+        Args:
+            commit_upto: Commit number to check (0..n-1)
+            target: Target board to check
+            read_func_sizes: True to read function size information
+
+        Returns:
+            Outcome object
+        """
+        done_file = self.GetDoneFile(commit_upto, target)
+        sizes_file = self.GetSizesFile(commit_upto, target)
+        sizes = {}
+        func_sizes = {}
+        if os.path.exists(done_file):
+            with open(done_file, 'r') as fd:
+                return_code = int(fd.readline())
+                err_lines = []
+                err_file = self.GetErrFile(commit_upto, target)
+                if os.path.exists(err_file):
+                    with open(err_file, 'r') as fd:
+                        err_lines = self.FilterErrors(fd.readlines())
+
+                # Decide whether the build was ok, failed or created warnings
+                if return_code:
+                    rc = OUTCOME_ERROR
+                elif len(err_lines):
+                    rc = OUTCOME_WARNING
+                else:
+                    rc = OUTCOME_OK
+
+                # Convert size information to our simple format
+                if os.path.exists(sizes_file):
+                    with open(sizes_file, 'r') as fd:
+                        for line in fd.readlines():
+                            values = line.split()
+                            rodata = 0
+                            if len(values) > 6:
+                                rodata = int(values[6], 16)
+                            size_dict = {
+                                'all' : int(values[0]) + int(values[1]) +
+                                        int(values[2]),
+                                'text' : int(values[0]) - rodata,
+                                'data' : int(values[1]),
+                                'bss' : int(values[2]),
+                                'rodata' : rodata,
+                            }
+                            sizes[values[5]] = size_dict
+
+            if read_func_sizes:
+                pattern = self.GetFuncSizesFile(commit_upto, target, '*')
+                for fname in glob.glob(pattern):
+                    with open(fname, 'r') as fd:
+                        dict_name = os.path.basename(fname).replace('.sizes',
+                                                                    '')
+                        func_sizes[dict_name] = self.ReadFuncSizes(fname, fd)
+
+            return Builder.Outcome(rc, err_lines, sizes, func_sizes)
+
+        return Builder.Outcome(OUTCOME_UNKNOWN, [], {}, {})
+
+    def GetResultSummary(self, boards_selected, commit_upto, read_func_sizes):
+        """Calculate a summary of the results of building a commit.
+
+        Args:
+            board_selected: Dict containing boards to summarise
+            commit_upto: Commit number to summarize (0..self.count-1)
+            read_func_sizes: True to read function size information
+
+        Returns:
+            Tuple:
+                Dict containing boards which passed building this commit.
+                    keyed by board.target
+                List containing a summary of error/warning lines
+        """
+        board_dict = {}
+        err_lines_summary = []
+
+        for board in boards_selected.itervalues():
+            outcome = self.GetBuildOutcome(commit_upto, board.target,
+                                           read_func_sizes)
+            board_dict[board.target] = outcome
+            for err in outcome.err_lines:
+                if err and not err.rstrip() in err_lines_summary:
+                    err_lines_summary.append(err.rstrip())
+        return board_dict, err_lines_summary
+
+    def AddOutcome(self, board_dict, arch_list, changes, char, color):
+        """Add an output to our list of outcomes for each architecture
+
+        This simple function adds failing boards (changes) to the
+        relevant architecture string, so we can print the results out
+        sorted by architecture.
+
+        Args:
+             board_dict: Dict containing all boards
+             arch_list: Dict keyed by arch name. Value is a string containing
+                    a list of board names which failed for that arch.
+             changes: List of boards to add to arch_list
+             color: terminal.Colour object
+        """
+        done_arch = {}
+        for target in changes:
+            if target in board_dict:
+                arch = board_dict[target].arch
+            else:
+                arch = 'unknown'
+            str = self.col.Color(color, ' ' + target)
+            if not arch in done_arch:
+                str = self.col.Color(color, char) + '  ' + str
+                done_arch[arch] = True
+            if not arch in arch_list:
+                arch_list[arch] = str
+            else:
+                arch_list[arch] += str
+
+
+    def ColourNum(self, num):
+        color = self.col.RED if num > 0 else self.col.GREEN
+        if num == 0:
+            return '0'
+        return self.col.Color(color, str(num))
+
+    def ResetResultSummary(self, board_selected):
+        """Reset the results summary ready for use.
+
+        Set up the base board list to be all those selected, and set the
+        error lines to empty.
+
+        Following this, calls to PrintResultSummary() will use this
+        information to work out what has changed.
+
+        Args:
+            board_selected: Dict containing boards to summarise, keyed by
+                board.target
+        """
+        self._base_board_dict = {}
+        for board in board_selected:
+            self._base_board_dict[board] = Builder.Outcome(0, [], [], {})
+        self._base_err_lines = []
+
+    def PrintFuncSizeDetail(self, fname, old, new):
+        grow, shrink, add, remove, up, down = 0, 0, 0, 0, 0, 0
+        delta, common = [], {}
+
+        for a in old:
+            if a in new:
+                common[a] = 1
+
+        for name in old:
+            if name not in common:
+                remove += 1
+                down += old[name]
+                delta.append([-old[name], name])
+
+        for name in new:
+            if name not in common:
+                add += 1
+                up += new[name]
+                delta.append([new[name], name])
+
+        for name in common:
+                diff = new.get(name, 0) - old.get(name, 0)
+                if diff > 0:
+                    grow, up = grow + 1, up + diff
+                elif diff < 0:
+                    shrink, down = shrink + 1, down - diff
+                delta.append([diff, name])
+
+        delta.sort()
+        delta.reverse()
+
+        args = [add, -remove, grow, -shrink, up, -down, up - down]
+        if max(args) == 0:
+            return
+        args = [self.ColourNum(x) for x in args]
+        indent = ' ' * 15
+        print ('%s%s: add: %s/%s, grow: %s/%s bytes: %s/%s (%s)' %
+               tuple([indent, self.col.Color(self.col.YELLOW, fname)] + args))
+        print '%s  %-38s %7s %7s %+7s' % (indent, 'function', 'old', 'new',
+                                        'delta')
+        for diff, name in delta:
+            if diff:
+                color = self.col.RED if diff > 0 else self.col.GREEN
+                msg = '%s  %-38s %7s %7s %+7d' % (indent, name,
+                        old.get(name, '-'), new.get(name,'-'), diff)
+                print self.col.Color(color, msg)
+
+
+    def PrintSizeDetail(self, target_list, show_bloat):
+        """Show details size information for each board
+
+        Args:
+            target_list: List of targets, each a dict containing:
+                    'target': Target name
+                    'total_diff': Total difference in bytes across all areas
+                    <part_name>: Difference for that part
+            show_bloat: Show detail for each function
+        """
+        targets_by_diff = sorted(target_list, reverse=True,
+        key=lambda x: x['_total_diff'])
+        for result in targets_by_diff:
+            printed_target = False
+            for name in sorted(result):
+                diff = result[name]
+                if name.startswith('_'):
+                    continue
+                if diff != 0:
+                    color = self.col.RED if diff > 0 else self.col.GREEN
+                msg = ' %s %+d' % (name, diff)
+                if not printed_target:
+                    print '%10s  %-15s:' % ('', result['_target']),
+                    printed_target = True
+                print self.col.Color(color, msg),
+            if printed_target:
+                print
+                if show_bloat:
+                    target = result['_target']
+                    outcome = result['_outcome']
+                    base_outcome = self._base_board_dict[target]
+                    for fname in outcome.func_sizes:
+                        self.PrintFuncSizeDetail(fname,
+                                                 base_outcome.func_sizes[fname],
+                                                 outcome.func_sizes[fname])
+
+
+    def PrintSizeSummary(self, board_selected, board_dict, show_detail,
+                         show_bloat):
+        """Print a summary of image sizes broken down by section.
+
+        The summary takes the form of one line per architecture. The
+        line contains deltas for each of the sections (+ means the section
+        got bigger, - means smaller). The nunmbers are the average number
+        of bytes that a board in this section increased by.
+
+        For example:
+           powerpc: (622 boards)   text -0.0
+          arm: (285 boards)   text -0.0
+          nds32: (3 boards)   text -8.0
+
+        Args:
+            board_selected: Dict containing boards to summarise, keyed by
+                board.target
+            board_dict: Dict containing boards for which we built this
+                commit, keyed by board.target. The value is an Outcome object.
+            show_detail: Show detail for each board
+            show_bloat: Show detail for each function
+        """
+        arch_list = {}
+        arch_count = {}
+
+        # Calculate changes in size for different image parts
+        # The previous sizes are in Board.sizes, for each board
+        for target in board_dict:
+            if target not in board_selected:
+                continue
+            base_sizes = self._base_board_dict[target].sizes
+            outcome = board_dict[target]
+            sizes = outcome.sizes
+
+            # Loop through the list of images, creating a dict of size
+            # changes for each image/part. We end up with something like
+            # {'target' : 'snapper9g45, 'data' : 5, 'u-boot-spl:text' : -4}
+            # which means that U-Boot data increased by 5 bytes and SPL
+            # text decreased by 4.
+            err = {'_target' : target}
+            for image in sizes:
+                if image in base_sizes:
+                    base_image = base_sizes[image]
+                    # Loop through the text, data, bss parts
+                    for part in sorted(sizes[image]):
+                        diff = sizes[image][part] - base_image[part]
+                        col = None
+                        if diff:
+                            if image == 'u-boot':
+                                name = part
+                            else:
+                                name = image + ':' + part
+                            err[name] = diff
+            arch = board_selected[target].arch
+            if not arch in arch_count:
+                arch_count[arch] = 1
+            else:
+                arch_count[arch] += 1
+            if not sizes:
+                pass    # Only add to our list when we have some stats
+            elif not arch in arch_list:
+                arch_list[arch] = [err]
+            else:
+                arch_list[arch].append(err)
+
+        # We now have a list of image size changes sorted by arch
+        # Print out a summary of these
+        for arch, target_list in arch_list.iteritems():
+            # Get total difference for each type
+            totals = {}
+            for result in target_list:
+                total = 0
+                for name, diff in result.iteritems():
+                    if name.startswith('_'):
+                        continue
+                    total += diff
+                    if name in totals:
+                        totals[name] += diff
+                    else:
+                        totals[name] = diff
+                result['_total_diff'] = total
+                result['_outcome'] = board_dict[result['_target']]
+
+            count = len(target_list)
+            printed_arch = False
+            for name in sorted(totals):
+                diff = totals[name]
+                if diff:
+                    # Display the average difference in this name for this
+                    # architecture
+                    avg_diff = float(diff) / count
+                    color = self.col.RED if avg_diff > 0 else self.col.GREEN
+                    msg = ' %s %+1.1f' % (name, avg_diff)
+                    if not printed_arch:
+                        print '%10s: (for %d/%d boards)' % (arch, count,
+                                arch_count[arch]),
+                        printed_arch = True
+                    print self.col.Color(color, msg),
+
+            if printed_arch:
+                print
+                if show_detail:
+                    self.PrintSizeDetail(target_list, show_bloat)
+
+
+    def PrintResultSummary(self, board_selected, board_dict, err_lines,
+                           show_sizes, show_detail, show_bloat):
+        """Compare results with the base results and display delta.
+
+        Only boards mentioned in board_selected will be considered. This
+        function is intended to be called repeatedly with the results of
+        each commit. It therefore shows a 'diff' between what it saw in
+        the last call and what it sees now.
+
+        Args:
+            board_selected: Dict containing boards to summarise, keyed by
+                board.target
+            board_dict: Dict containing boards for which we built this
+                commit, keyed by board.target. The value is an Outcome object.
+            err_lines: A list of errors for this commit, or [] if there is
+                none, or we don't want to print errors
+            show_sizes: Show image size deltas
+            show_detail: Show detail for each board
+            show_bloat: Show detail for each function
+        """
+        better = []     # List of boards fixed since last commit
+        worse = []      # List of new broken boards since last commit
+        new = []        # List of boards that didn't exist last time
+        unknown = []    # List of boards that were not built
+
+        for target in board_dict:
+            if target not in board_selected:
+                continue
+
+            # If the board was built last time, add its outcome to a list
+            if target in self._base_board_dict:
+                base_outcome = self._base_board_dict[target].rc
+                outcome = board_dict[target]
+                if outcome.rc == OUTCOME_UNKNOWN:
+                    unknown.append(target)
+                elif outcome.rc < base_outcome:
+                    better.append(target)
+                elif outcome.rc > base_outcome:
+                    worse.append(target)
+            else:
+                new.append(target)
+
+        # Get a list of errors that have appeared, and disappeared
+        better_err = []
+        worse_err = []
+        for line in err_lines:
+            if line not in self._base_err_lines:
+                worse_err.append('+' + line)
+        for line in self._base_err_lines:
+            if line not in err_lines:
+                better_err.append('-' + line)
+
+        # Display results by arch
+        if better or worse or unknown or new or worse_err or better_err:
+            arch_list = {}
+            self.AddOutcome(board_selected, arch_list, better, '',
+                    self.col.GREEN)
+            self.AddOutcome(board_selected, arch_list, worse, '+',
+                    self.col.RED)
+            self.AddOutcome(board_selected, arch_list, new, '*', self.col.BLUE)
+            if self._show_unknown:
+                self.AddOutcome(board_selected, arch_list, unknown, '?',
+                        self.col.MAGENTA)
+            for arch, target_list in arch_list.iteritems():
+                print '%10s: %s' % (arch, target_list)
+            if better_err:
+                print self.col.Color(self.col.GREEN, '\n'.join(better_err))
+            if worse_err:
+                print self.col.Color(self.col.RED, '\n'.join(worse_err))
+
+        if show_sizes:
+            self.PrintSizeSummary(board_selected, board_dict, show_detail,
+                                  show_bloat)
+
+        # Save our updated information for the next call to this function
+        self._base_board_dict = board_dict
+        self._base_err_lines = err_lines
+
+        # Get a list of boards that did not get built, if needed
+        not_built = []
+        for board in board_selected:
+            if not board in board_dict:
+                not_built.append(board)
+        if not_built:
+            print "Boards not built (%d): %s" % (len(not_built),
+                    ', '.join(not_built))
+
+
+    def ShowSummary(self, commits, board_selected, show_errors, show_sizes,
+                    show_detail, show_bloat):
+        """Show a build summary for U-Boot for a given board list.
+
+        Reset the result summary, then repeatedly call GetResultSummary on
+        each commit's results, then display the differences we see.
+
+        Args:
+            commit: Commit objects to summarise
+            board_selected: Dict containing boards to summarise
+            show_errors: Show errors that occured
+            show_sizes: Show size deltas
+            show_detail: Show detail for each board
+            show_bloat: Show detail for each function
+        """
+        self.commit_count = len(commits)
+        self.commits = commits
+        self.ResetResultSummary(board_selected)
+
+        for commit_upto in range(0, self.commit_count, self._step):
+            board_dict, err_lines = self.GetResultSummary(board_selected,
+                    commit_upto, read_func_sizes=show_bloat)
+            msg = '%02d: %s' % (commit_upto + 1, commits[commit_upto].subject)
+            print self.col.Color(self.col.BLUE, msg)
+            self.PrintResultSummary(board_selected, board_dict,
+                    err_lines if show_errors else [], show_sizes, show_detail,
+                    show_bloat)
+
+
+    def SetupBuild(self, board_selected, commits):
+        """Set up ready to start a build.
+
+        Args:
+            board_selected: Selected boards to build
+            commits: Selected commits to build
+        """
+        # First work out how many commits we will build
+        count = (len(commits) + self._step - 1) / self._step
+        self.count = len(board_selected) * count
+        self.upto = self.warned = self.fail = 0
+        self._timestamps = collections.deque()
+
+    def BuildBoardsForCommit(self, board_selected, keep_outputs):
+        """Build all boards for a single commit"""
+        self.SetupBuild(board_selected)
+        self.count = len(board_selected)
+        for brd in board_selected.itervalues():
+            job = BuilderJob()
+            job.board = brd
+            job.commits = None
+            job.keep_outputs = keep_outputs
+            self.queue.put(brd)
+
+        self.queue.join()
+        self.out_queue.join()
+        print
+        self.ClearLine(0)
+
+    def BuildCommits(self, commits, board_selected, show_errors, keep_outputs):
+        """Build all boards for all commits (non-incremental)"""
+        self.commit_count = len(commits)
+
+        self.ResetResultSummary(board_selected)
+        for self.commit_upto in range(self.commit_count):
+            self.SelectCommit(commits[self.commit_upto])
+            self.SelectOutputDir()
+            Mkdir(self.output_dir)
+
+            self.BuildBoardsForCommit(board_selected, keep_outputs)
+            board_dict, err_lines = self.GetResultSummary()
+            self.PrintResultSummary(board_selected, board_dict,
+                err_lines if show_errors else [])
+
+        if self.already_done:
+            print '%d builds already done' % self.already_done
+
+    def GetThreadDir(self, thread_num):
+        """Get the directory path to the working dir for a thread.
+
+        Args:
+            thread_num: Number of thread to check.
+        """
+        return os.path.join(self._working_dir, '%02d' % thread_num)
+
+    def _PrepareThread(self, thread_num):
+        """Prepare the working directory for a thread.
+
+        This clones or fetches the repo into the thread's work directory.
+
+        Args:
+            thread_num: Thread number (0, 1, ...)
+        """
+        thread_dir = self.GetThreadDir(thread_num)
+        Mkdir(thread_dir)
+        git_dir = os.path.join(thread_dir, '.git')
+
+        # Clone the repo if it doesn't already exist
+        # TODO(sjg@chromium): Perhaps some git hackery to symlink instead, so
+        # we have a private index but uses the origin repo's contents?
+        if self.git_dir:
+            src_dir = os.path.abspath(self.git_dir)
+            if os.path.exists(git_dir):
+                gitutil.Fetch(git_dir, thread_dir)
+            else:
+                print 'Cloning repo for thread %d' % thread_num
+                gitutil.Clone(src_dir, thread_dir)
+
+    def _PrepareWorkingSpace(self, max_threads):
+        """Prepare the working directory for use.
+
+        Set up the git repo for each thread.
+
+        Args:
+            max_threads: Maximum number of threads we expect to need.
+        """
+        Mkdir(self._working_dir)
+        for thread in range(max_threads):
+            self._PrepareThread(thread)
+
+    def _PrepareOutputSpace(self):
+        """Get the output directories ready to receive files.
+
+        We delete any output directories which look like ones we need to
+        create. Having left over directories is confusing when the user wants
+        to check the output manually.
+        """
+        dir_list = []
+        for commit_upto in range(self.commit_count):
+            dir_list.append(self._GetOutputDir(commit_upto))
+
+        for dirname in glob.glob(os.path.join(self.base_dir, '*')):
+            if dirname not in dir_list:
+                shutil.rmtree(dirname)
+
+    def BuildBoards(self, commits, board_selected, show_errors, keep_outputs):
+        """Build all commits for a list of boards
+
+        Args:
+            commits: List of commits to be build, each a Commit object
+            boards_selected: Dict of selected boards, key is target name,
+                    value is Board object
+            show_errors: True to show summarised error/warning info
+            keep_outputs: True to save build output files
+        """
+        self.commit_count = len(commits)
+        self.commits = commits
+
+        self.ResetResultSummary(board_selected)
+        Mkdir(self.base_dir)
+        self._PrepareWorkingSpace(min(self.num_threads, len(board_selected)))
+        self._PrepareOutputSpace()
+        self.SetupBuild(board_selected, commits)
+        self.ProcessResult(None)
+
+        # Create jobs to build all commits for each board
+        for brd in board_selected.itervalues():
+            job = BuilderJob()
+            job.board = brd
+            job.commits = commits
+            job.keep_outputs = keep_outputs
+            job.step = self._step
+            self.queue.put(job)
+
+        # Wait until all jobs are started
+        self.queue.join()
+
+        # Wait until we have processed all output
+        self.out_queue.join()
+        print
+        self.ClearLine(0)