Add 'patman' patch generation, checking and submission script

What is this?

=============

This tool is a Python script which:
- Creates patch directly from your branch
- Cleans them up by removing unwanted tags
- Inserts a cover letter with change lists
- Runs the patches through checkpatch.pl and its own checks
- Optionally emails them out to selected people

It is intended to automate patch creation and make it a less
error-prone process. It is useful for U-Boot and Linux work so far,
since it uses the checkpatch.pl script.

It is configured almost entirely by tags it finds in your commits.
This means that you can work on a number of different branches at
once, and keep the settings with each branch rather than having to
git format-patch, git send-email, etc. with the correct parameters
each time. So for example if you put:

in one of your commits, the series will be sent there.

See the README file for full details.
END

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/patman/patchstream.py b/tools/patman/patchstream.py
new file mode 100644
index 0000000..be40af3
--- /dev/null
+++ b/tools/patman/patchstream.py
@@ -0,0 +1,444 @@
+# Copyright (c) 2011 The Chromium OS Authors.
+#
+# 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 os
+import re
+import shutil
+import tempfile
+
+import command
+import commit
+import gitutil
+from series import Series
+
+# Tags that we detect and remove
+re_remove = re.compile('^BUG=|^TEST=|^Change-Id:|^Review URL:'
+    '|Reviewed-on:|Reviewed-by:')
+
+# Lines which are allowed after a TEST= line
+re_allowed_after_test = re.compile('^Signed-off-by:')
+
+# The start of the cover letter
+re_cover = re.compile('^Cover-letter:')
+
+# Patch series tag
+re_series = re.compile('^Series-(\w*): *(.*)')
+
+# Commit tags that we want to collect and keep
+re_tag = re.compile('^(Tested-by|Acked-by|Signed-off-by|Cc): (.*)')
+
+# The start of a new commit in the git log
+re_commit = re.compile('^commit (.*)')
+
+# We detect these since checkpatch doesn't always do it
+re_space_before_tab = re.compile('^[+].* \t')
+
+# States we can be in - can we use range() and still have comments?
+STATE_MSG_HEADER = 0        # Still in the message header
+STATE_PATCH_SUBJECT = 1     # In patch subject (first line of log for a commit)
+STATE_PATCH_HEADER = 2      # In patch header (after the subject)
+STATE_DIFFS = 3             # In the diff part (past --- line)
+
+class PatchStream:
+    """Class for detecting/injecting tags in a patch or series of patches
+
+    We support processing the output of 'git log' to read out the tags we
+    are interested in. We can also process a patch file in order to remove
+    unwanted tags or inject additional ones. These correspond to the two
+    phases of processing.
+    """
+    def __init__(self, series, name=None, is_log=False):
+        self.skip_blank = False          # True to skip a single blank line
+        self.found_test = False          # Found a TEST= line
+        self.lines_after_test = 0        # MNumber of lines found after TEST=
+        self.warn = []                   # List of warnings we have collected
+        self.linenum = 1                 # Output line number we are up to
+        self.in_section = None           # Name of start...END section we are in
+        self.notes = []                  # Series notes
+        self.section = []                # The current section...END section
+        self.series = series             # Info about the patch series
+        self.is_log = is_log             # True if indent like git log
+        self.in_change = 0               # Non-zero if we are in a change list
+        self.blank_count = 0             # Number of blank lines stored up
+        self.state = STATE_MSG_HEADER    # What state are we in?
+        self.tags = []                   # Tags collected, like Tested-by...
+        self.signoff = []                # Contents of signoff line
+        self.commit = None               # Current commit
+
+    def AddToSeries(self, line, name, value):
+        """Add a new Series-xxx tag.
+
+        When a Series-xxx tag is detected, we come here to record it, if we
+        are scanning a 'git log'.
+
+        Args:
+            line: Source line containing tag (useful for debug/error messages)
+            name: Tag name (part after 'Series-')
+            value: Tag value (part after 'Series-xxx: ')
+        """
+        if name == 'notes':
+            self.in_section = name
+            self.skip_blank = False
+        if self.is_log:
+            self.series.AddTag(self.commit, line, name, value)
+
+    def CloseCommit(self):
+        """Save the current commit into our commit list, and reset our state"""
+        if self.commit and self.is_log:
+            self.series.AddCommit(self.commit)
+            self.commit = None
+
+    def FormatTags(self, tags):
+        out_list = []
+        for tag in sorted(tags):
+            if tag.startswith('Cc:'):
+                tag_list = tag[4:].split(',')
+                out_list += gitutil.BuildEmailList(tag_list, 'Cc:')
+            else:
+                out_list.append(tag)
+        return out_list
+
+    def ProcessLine(self, line):
+        """Process a single line of a patch file or commit log
+
+        This process a line and returns a list of lines to output. The list
+        may be empty or may contain multiple output lines.
+
+        This is where all the complicated logic is located. The class's
+        state is used to move between different states and detect things
+        properly.
+
+        We can be in one of two modes:
+            self.is_log == True: This is 'git log' mode, where most output is
+                indented by 4 characters and we are scanning for tags
+
+            self.is_log == False: This is 'patch' mode, where we already have
+                all the tags, and are processing patches to remove junk we
+                don't want, and add things we think are required.
+
+        Args:
+            line: text line to process
+
+        Returns:
+            list of output lines, or [] if nothing should be output
+        """
+        # Initially we have no output. Prepare the input line string
+        out = []
+        line = line.rstrip('\n')
+        if self.is_log:
+            if line[:4] == '    ':
+                line = line[4:]
+
+        # Handle state transition and skipping blank lines
+        series_match = re_series.match(line)
+        commit_match = re_commit.match(line) if self.is_log else None
+        tag_match = None
+        if self.state == STATE_PATCH_HEADER:
+            tag_match = re_tag.match(line)
+        is_blank = not line.strip()
+        if is_blank:
+            if (self.state == STATE_MSG_HEADER
+                    or self.state == STATE_PATCH_SUBJECT):
+                self.state += 1
+
+            # We don't have a subject in the text stream of patch files
+            # It has its own line with a Subject: tag
+            if not self.is_log and self.state == STATE_PATCH_SUBJECT:
+                self.state += 1
+        elif commit_match:
+            self.state = STATE_MSG_HEADER
+
+        # If we are in a section, keep collecting lines until we see END
+        if self.in_section:
+            if line == 'END':
+                if self.in_section == 'cover':
+                    self.series.cover = self.section
+                elif self.in_section == 'notes':
+                    if self.is_log:
+                        self.series.notes += self.section
+                else:
+                    self.warn.append("Unknown section '%s'" % self.in_section)
+                self.in_section = None
+                self.skip_blank = True
+                self.section = []
+            else:
+                self.section.append(line)
+
+        # Detect the commit subject
+        elif not is_blank and self.state == STATE_PATCH_SUBJECT:
+            self.commit.subject = line
+
+        # Detect the tags we want to remove, and skip blank lines
+        elif re_remove.match(line):
+            self.skip_blank = True
+
+            # TEST= should be the last thing in the commit, so remove
+            # everything after it
+            if line.startswith('TEST='):
+                self.found_test = True
+        elif self.skip_blank and is_blank:
+            self.skip_blank = False
+
+        # Detect the start of a cover letter section
+        elif re_cover.match(line):
+            self.in_section = 'cover'
+            self.skip_blank = False
+
+        # If we are in a change list, key collected lines until a blank one
+        elif self.in_change:
+            if is_blank:
+                # Blank line ends this change list
+                self.in_change = 0
+            else:
+                self.series.AddChange(self.in_change, self.commit, line)
+            self.skip_blank = False
+
+        # Detect Series-xxx tags
+        elif series_match:
+            name = series_match.group(1)
+            value = series_match.group(2)
+            if name == 'changes':
+                # value is the version number: e.g. 1, or 2
+                try:
+                    value = int(value)
+                except ValueError as str:
+                    raise ValueError("%s: Cannot decode version info '%s'" %
+                        (self.commit.hash, line))
+                self.in_change = int(value)
+            else:
+                self.AddToSeries(line, name, value)
+                self.skip_blank = True
+
+        # Detect the start of a new commit
+        elif commit_match:
+            self.CloseCommit()
+            self.commit = commit.Commit(commit_match.group(1)[:7])
+
+        # Detect tags in the commit message
+        elif tag_match:
+            # Onlly allow a single signoff tag
+            if tag_match.group(1) == 'Signed-off-by':
+                if self.signoff:
+                    self.warn.append('Patch has more than one Signed-off-by '
+                            'tag')
+                self.signoff += [line]
+
+            # Remove Tested-by self, since few will take much notice
+            elif (tag_match.group(1) == 'Tested-by' and
+                    tag_match.group(2).find(os.getenv('USER') + '@') != -1):
+                self.warn.append("Ignoring %s" % line)
+            elif tag_match.group(1) == 'Cc':
+                self.commit.AddCc(tag_match.group(2).split(','))
+            else:
+                self.tags.append(line);
+
+        # Well that means this is an ordinary line
+        else:
+            pos = 1
+            # Look for ugly ASCII characters
+            for ch in line:
+                # TODO: Would be nicer to report source filename and line
+                if ord(ch) > 0x80:
+                    self.warn.append("Line %d/%d ('%s') has funny ascii char" %
+                        (self.linenum, pos, line))
+                pos += 1
+
+            # Look for space before tab
+            m = re_space_before_tab.match(line)
+            if m:
+                self.warn.append('Line %d/%d has space before tab' %
+                    (self.linenum, m.start()))
+
+            # OK, we have a valid non-blank line
+            out = [line]
+            self.linenum += 1
+            self.skip_blank = False
+            if self.state == STATE_DIFFS:
+                pass
+
+            # If this is the start of the diffs section, emit our tags and
+            # change log
+            elif line == '---':
+                self.state = STATE_DIFFS
+
+                # Output the tags (signeoff first), then change list
+                out = []
+                if self.signoff:
+                    out += self.signoff
+                log = self.series.MakeChangeLog(self.commit)
+                out += self.FormatTags(self.tags)
+                out += [line] + log
+            elif self.found_test:
+                if not re_allowed_after_test.match(line):
+                    self.lines_after_test += 1
+
+        return out
+
+    def Finalize(self):
+        """Close out processing of this patch stream"""
+        self.CloseCommit()
+        if self.lines_after_test:
+            self.warn.append('Found %d lines after TEST=' %
+                    self.lines_after_test)
+
+    def ProcessStream(self, infd, outfd):
+        """Copy a stream from infd to outfd, filtering out unwanting things.
+
+        This is used to process patch files one at a time.
+
+        Args:
+            infd: Input stream file object
+            outfd: Output stream file object
+        """
+        # Extract the filename from each diff, for nice warnings
+        fname = None
+        last_fname = None
+        re_fname = re.compile('diff --git a/(.*) b/.*')
+        while True:
+            line = infd.readline()
+            if not line:
+                break
+            out = self.ProcessLine(line)
+
+            # Try to detect blank lines at EOF
+            for line in out:
+                match = re_fname.match(line)
+                if match:
+                    last_fname = fname
+                    fname = match.group(1)
+                if line == '+':
+                    self.blank_count += 1
+                else:
+                    if self.blank_count and (line == '-- ' or match):
+                        self.warn.append("Found possible blank line(s) at "
+                                "end of file '%s'" % last_fname)
+                    outfd.write('+\n' * self.blank_count)
+                    outfd.write(line + '\n')
+                    self.blank_count = 0
+        self.Finalize()
+
+
+def GetMetaData(start, count):
+    """Reads out patch series metadata from the commits
+
+    This does a 'git log' on the relevant commits and pulls out the tags we
+    are interested in.
+
+    Args:
+        start: Commit to start from: 0=HEAD, 1=next one, etc.
+        count: Number of commits to list
+    """
+    pipe = [['git', 'log', '--reverse', 'HEAD~%d' % start, '-n%d' % count]]
+    stdout = command.RunPipe(pipe, capture=True)
+    series = Series()
+    ps = PatchStream(series, is_log=True)
+    for line in stdout.splitlines():
+        ps.ProcessLine(line)
+    ps.Finalize()
+    return series
+
+def FixPatch(backup_dir, fname, series, commit):
+    """Fix up a patch file, by adding/removing as required.
+
+    We remove our tags from the patch file, insert changes lists, etc.
+    The patch file is processed in place, and overwritten.
+
+    A backup file is put into backup_dir (if not None).
+
+    Args:
+        fname: Filename to patch file to process
+        series: Series information about this patch set
+        commit: Commit object for this patch file
+    Return:
+        A list of errors, or [] if all ok.
+    """
+    handle, tmpname = tempfile.mkstemp()
+    outfd = os.fdopen(handle, 'w')
+    infd = open(fname, 'r')
+    ps = PatchStream(series)
+    ps.commit = commit
+    ps.ProcessStream(infd, outfd)
+    infd.close()
+    outfd.close()
+
+    # Create a backup file if required
+    if backup_dir:
+        shutil.copy(fname, os.path.join(backup_dir, os.path.basename(fname)))
+    shutil.move(tmpname, fname)
+    return ps.warn
+
+def FixPatches(series, fnames):
+    """Fix up a list of patches identified by filenames
+
+    The patch files are processed in place, and overwritten.
+
+    Args:
+        series: The series object
+        fnames: List of patch files to process
+    """
+    # Current workflow creates patches, so we shouldn't need a backup
+    backup_dir = None  #tempfile.mkdtemp('clean-patch')
+    count = 0
+    for fname in fnames:
+        commit = series.commits[count]
+        commit.patch = fname
+        result = FixPatch(backup_dir, fname, series, commit)
+        if result:
+            print '%d warnings for %s:' % (len(result), fname)
+            for warn in result:
+                print '\t', warn
+            print
+        count += 1
+    print 'Cleaned %d patches' % count
+    return series
+
+def InsertCoverLetter(fname, series, count):
+    """Inserts a cover letter with the required info into patch 0
+
+    Args:
+        fname: Input / output filename of the cover letter file
+        series: Series object
+        count: Number of patches in the series
+    """
+    fd = open(fname, 'r')
+    lines = fd.readlines()
+    fd.close()
+
+    fd = open(fname, 'w')
+    text = series.cover
+    prefix = series.GetPatchPrefix()
+    for line in lines:
+        if line.startswith('Subject:'):
+            # TODO: if more than 10 patches this should save 00/xx, not 0/xx
+            line = 'Subject: [%s 0/%d] %s\n' % (prefix, count, text[0])
+
+        # Insert our cover letter
+        elif line.startswith('*** BLURB HERE ***'):
+            # First the blurb test
+            line = '\n'.join(text[1:]) + '\n'
+            if series.get('notes'):
+                line += '\n'.join(series.notes) + '\n'
+
+            # Now the change list
+            out = series.MakeChangeLog(None)
+            line += '\n' + '\n'.join(out)
+        fd.write(line)
+    fd.close()