doc/manual/primer/patches.txt

   1 /** @page primerpatches Patch Primer
   2
   3 This page provides an introduction to patching that may be useful
   4 for OpenOCD contributors who are unfamiliar with the process.
   5
   6 @section primerpatchintro Introduction to Patching
   7
   8 The standard method for creating patches requires developers to:
   9 - checkout the git repository (or bring a copy up-to-date),
  10 - make the necessary modifications to a working copy,
  11 - check with 'git status' to see which files will be modified/added, and
  12 - use 'git diff' to review the changes and produce a patch.
  13
  14 It is important to minimize the changes to only those lines that contain
  15 important differences; do not allow stray whitespace changes into your
  16 patches, and keep the focus to a single logical change.
  17
  18 @section primerpatchcreate Creating Patches
  19
  20 You can create a patch (from the root of your working copy) with a
  21 command like the following example: @par
  22 @verbatim
  23 git diff > patch-name.patch
  24 @endverbatim
  25
  26 where @a patch-name should be something that is descriptive and unique.
  27
  28 The above command will create a patch containing all of the changes in
  29 the working copy; if you want to obtain a subset, simply provide the
  30 list of files to the command: @par
  31 @verbatim
  32 git diff doc > <patch-name>-doc.patch
  33 git diff src > <patch-name>-src.patch
  34 @endverbatim
  35
  36 This will create two patches, each containing only those changes present
  37 in the subdirectory specified.
  38
  39 @subsection primerpatchcreate Naming Patches
  40
  41 One developer has evolved an informal standard for naming his patches: @par
  42 @verbatim
  43 <project>-<lod>-<action>-<task>.patch
  44 @endverbatim
  45
  46 where @a project is @c openocd, @a lod (line-of-development) could be a
  47 subsystem (e.g. @c jtag, @c jlink, etc.) or other group identifier,
  48 @a action is @c add, @c change, @c fix, @c update, etc., and @a task is
  49 whatever the patch will accomplish (in 2-4 words).
  50
  51 This scheme does not need to be followed, but it is helpful for
  52 maintainers that receive many patches.  You do not want your own
  53 @c openocd.patch file to be accidentally overwritten by another
  54 submission, sending your patch to the bit bucket on accident.
  55
  56 @section primerpatchpreflight Developer Review
  57
  58 Before sending in patches, please make sure you have updated to the
  59 latest version of the trunk (using <code>git pull</code>) before creating
  60 your patch.  This helps to increase the chances that it will apply
  61 cleanly to the trunk.  However, the content matters most.
  62
  63 When creating a patch using "<code>git diff</code>", git will
  64 produce a patch that contains all of the changes in your working copy.
  65 To manage multiple changes at once, you either need one working copy per
  66 patch, or you can specified specific files and directories when using
  67 <code>git diff</code>.  Overlapping patches will be discussed in the
  68 next section.
  69
  70 @todo Does git's treatment of line-endings behave sanely?
  71 Basically, the repository should use newlines internally,
  72 and convert to/from CRLF on Windows etc.
  73
  74 @section primerpatchseries Patch Series
  75
  76 As was mentioned above, each patch should contain one logical @c task,
  77 and multiple logical tasks should be split into a series of patches.
  78 There are no hard guidelines for how that is to be done; it's an art
  79 form.  Many simple changes should not have to worry about being split,
  80 as they will naturally represent a single task.
  81
  82 When working on several different non-intersecting lines of development,
  83 a combination of multiple working copies and patch series management
  84 techniques can become critical to efficiently managing change.  This
  85 again is an area where developers have favorite methodologies that are
  86 simply a matter of taste or familiarity; your mileage may vary.
  87
  88 Packages such as @c patchutils, @c diffutils, and @c quilt are among
  89 those that have proved themselves invaluable for these type of tasks.
  90 Others take their patch management a step further, using stkgit or
  91 some other framework on top of git.
  92
  93 @subsection primerpatchseriesinterdiff Using @c interdiff
  94
  95 The @c patchutils package includes the @c interdiff command, which
  96 produces a patch that contains the changes made between two other
  97 patches.  This command can be used to manage the creation of trivial
  98 patch series.  For example, the following sequence of commands will
  99 produce three patches: @par
 100 @verbatim
 101 $ cd openocd/
 102 $ git pull
 103 ...
 104 $ <<<start changes for patch #1>>>
 105 ...
 106 $ <<<finish changes for patch #1>>>
 107 $ git diff > series-1.patch                         # patch #1 is easy
 108 $ <<<start changes for patch #2>>>
 109 ...
 110 $ <<<finish changes for patch #2>>>
 111 $ git diff > series-1+2.patch                       # create patch 1+2
 112 $ interdiff series-1{,+2}.patch > series-2.patch    #   1 ~  1+2  => #2
 113 $ <<<start changes for patch #3>>>
 114 ...
 115 $ <<<finish changes for patch #3>>>
 116 $ git diff > series-1+2+3.patch                     # create patch 1+2+3
 117 $ interdiff series-1+2{,+3}.patch > series-3.patch  # 1+2 ~ 1+2+3 => 3
 118 @endverbatim
 119
 120 This technique falls apart when the repository changes, but this may be
 121 suitable for small series of patches.
 122
 123 @subsection primerpatchseriesquilt Using @c quilt
 124
 125 The @c quilt package provides scripts to manage series of patches more
 126 efficiently than can be managed by hand.  For out-of-tree work projects
 127 that require such patch management, @c quilt provides an indispensable
 128 tool for solving the problem.
 129
 130 @section primerpatchsubmit Submitting Patches
 131
 132 Write access to the OpenOCD git repository is limited to
 133 contributors that have demonstrated the ability to produce clear,
 134 consistent, and frequent patches.  These individuals are responsible
 135 for maintaining the integrity of the repository for the community.
 136
 137 Thus, commits to the git repository must be handled by one of
 138 these maintainers.
 139
 140 Patches must be sent to the OpenOCD developer mailing list:
 141 @par
 142         openocd-devel@lists.sourceforge.net
 143
 144 They will be reviewed and committed if the changes are found to be
 145 acceptable.  If there are problems, you will receive feedback via the
 146 mailing list; in general, the maintainers prefer all communication to go
 147 through the list, as the entire community needs to judge contributions
 148 for possible merits and mistakes.
 149
 150 Contributors may be asked to address certain issues and submit a new
 151 patch.  In the event that it gets overlooked, you may need to resubmit
 152 it or prompt for feedback.  Please have patience, as many maintainers
 153 work on the project voluntarily and without compensation for the time
 154 that they spend doing these tasks.
 155
 156 @section primerpatchguide Guidelines for Submitting Patches
 157
 158 - Each patch file should contain:
 159   - A commit description that describes all of the changes.
 160   - A separator line that contains three hyphens: <code>---</code>
 161   - A summary of the changes produced by diffstat (optional)
 162   - Another separator line (optional)
 163   - The actual patch contents, containing a single change.
 164
 165 - Each patch series should include:
 166   - A summary of the patches in the series.
 167   - Logically-related patches that contain incremental changes.
 168
 169  */
 170 /** @file
 171 This file contains the @ref primerpatches page.
 172 */