vimdiff: add tool documentation

Running 'git {merge,diff}tool --tool-help' now also prints usage
information about the vimdiff tool (and its variants) instead of just
its name.

Two new functions ('diff_cmd_help()' and 'merge_cmd_help()') have been
added to the set of functions that each merge tool (ie. scripts found
inside "mergetools/") can overwrite to provided tool specific
information.

Right now, only 'mergetools/vimdiff' implements these functions, but
other tools are encouraged to do so in the future, specially if they
take configuration options not explained anywhere else (as it is the
case with the 'vimdiff' tool and the new 'layout' option)

Note that the function 'show_tool_names', used in the implementation of
'git mergetool --tool-help', is also used in Documentation/Makefile to
generate the list of allowed values for the configuration variables
'{diff,merge}.{gui,}tool'. Adjust the rule so its output is an Asciidoc
"description list" instead of a plain list, with the tool name as the
item and the newly added tool description as the description.

In addition, a section has been added to
"Documentation/git-mergetool.txt" to explain the new "layout"
configuration option with examples.

Helped-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Fernando Ramos <greenfoo@u92.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/Makefile b/Documentation/Makefile
index 1eb9192dae825fdbe40e6149a0f73359c1cde814..faed2854624edf1f0ce2dcb0ab143e64471634f3 100644 (file)
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -302,12 +302,12 @@ $(mergetools_txt): mergetools-list.made
 
 mergetools-list.made: ../git-mergetool--lib.sh $(wildcard ../mergetools/*)
        $(QUIET_GEN) \
-       $(SHELL_PATH) -c 'MERGE_TOOLS_DIR=../mergetools && \
+       $(SHELL_PATH) -c 'MERGE_TOOLS_DIR=../mergetools && TOOL_MODE=diff && \
                . ../git-mergetool--lib.sh && \
-               show_tool_names can_diff "* " || :' >mergetools-diff.txt && \
-       $(SHELL_PATH) -c 'MERGE_TOOLS_DIR=../mergetools && \
+               show_tool_names can_diff' | sed -e "s/\([a-z0-9]*\)/\`\1\`;;/" >mergetools-diff.txt && \
+       $(SHELL_PATH) -c 'MERGE_TOOLS_DIR=../mergetools && TOOL_MODE=merge && \
                . ../git-mergetool--lib.sh && \
-               show_tool_names can_merge "* " || :' >mergetools-merge.txt && \
+               show_tool_names can_merge' | sed -e "s/\([a-z0-9]*\)/\`\1\`;;/" >mergetools-merge.txt && \
        date >$@
 
 TRACK_ASCIIDOCFLAGS = $(subst ','\'',$(ASCIIDOC_COMMON):$(ASCIIDOC_HTML):$(ASCIIDOC_DOCBOOK))

diff --git a/Documentation/config/mergetool.txt b/Documentation/config/mergetool.txt
index cafbbef46ae9c102e9e175e67282badb67e09255..90b380970023a76799206a30789d4f8af7793991 100644 (file)
--- a/Documentation/config/mergetool.txt
+++ b/Documentation/config/mergetool.txt
@@ -45,6 +45,15 @@ mergetool.meld.useAutoMerge::
        value of `false` avoids using `--auto-merge` altogether, and is the
        default value.
 
+mergetool.vimdiff.layout::
+       The vimdiff backend uses this variable to control how its split
+       windows look like. Applies even if you are using Neovim (`nvim`) or
+       gVim (`gvim`) as the merge tool. See BACKEND SPECIFIC HINTS section
+ifndef::git-mergetool[]
+       in linkgit:git-mergetool[1].
+endif::[]
+       for details.
+
 mergetool.hideResolved::
        During a merge Git will automatically resolve as many conflicts as
        possible and write the 'MERGED' file containing conflict markers around

diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index e587c7763a7c21664c7586e273f348f70dd061d7..f784027bc13724712f902b115abd98bc1c04b43f 100644 (file)
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -101,6 +101,7 @@ success of the resolution after the custom tool has exited.
 
 CONFIGURATION
 -------------
+:git-mergetool: 1
 include::config/mergetool.txt[]
 
 TEMPORARY FILES
@@ -113,6 +114,13 @@ Setting the `mergetool.keepBackup` configuration variable to `false`
 causes `git mergetool` to automatically remove the backup as files
 are successfully merged.
 
+BACKEND SPECIFIC HINTS
+----------------------
+
+vimdiff
+~~~~~~~
+include::mergetools/vimdiff.txt[]
+
 GIT
 ---
 Part of the linkgit:git[1] suite

diff --git a/Documentation/mergetools/vimdiff.txt b/Documentation/mergetools/vimdiff.txt
new file mode 100644 (file)
index 0000000..2d631e9
--- /dev/null
+++ b/Documentation/mergetools/vimdiff.txt
@@ -0,0 +1,194 @@
+Description
+^^^^^^^^^^^
+
+When specifying `--tool=vimdiff` in `git mergetool` Git will open Vim with a 4
+windows layout distributed in the following way:
+....
+------------------------------------------
+|             |           |              |
+|   LOCAL     |   BASE    |   REMOTE     |
+|             |           |              |
+------------------------------------------
+|                                        |
+|                MERGED                  |
+|                                        |
+------------------------------------------
+....
+`LOCAL`, `BASE` and `REMOTE` are read-only buffers showing the contents of the
+conflicting file in specific commits ("commit you are merging into", "common
+ancestor commit" and "commit you are merging from" respectively)
+
+`MERGED` is a writable buffer where you have to resolve the conflicts (using the
+other read-only buffers as a reference). Once you are done, save and exit Vim as
+usual (`:wq`) or, if you want to abort, exit using `:cq`.
+
+Layout configuration
+^^^^^^^^^^^^^^^^^^^^
+
+You can change the windows layout used by Vim by setting configuration variable
+`mergetool.vimdiff.layout` which accepts a string where the following separators
+have special meaning:
+
+  - `+` is used to "open a new tab"
+  - `,` is used to "open a new vertical split"
+  - `/` is used to "open a new horizontal split"
+  - `@` is used to indicate which is the file containing the final version after
+    solving the conflicts. If not present, `MERGED` will be used by default.
+
+The precedence of the operators is this one (you can use parentheses to change
+it):
+
+    `@` > `+` > `/` > `,`
+
+Let's see some examples to understand how it works:
+
+* `layout = "(LOCAL,BASE,REMOTE)/MERGED"`
++
+--
+This is exactly the same as the default layout we have already seen.
+
+Note that `/` has precedence over `,` and thus the parenthesis are not
+needed in this case. The next layout definition is equivalent:
+
+    layout = "LOCAL,BASE,REMOTE / MERGED"
+--
+* `layout = "LOCAL,MERGED,REMOTE"`
++
+--
+If, for some reason, we are not interested in the `BASE` buffer.
+....
+------------------------------------------
+|             |           |              |
+|             |           |              |
+|   LOCAL     |   MERGED  |   REMOTE     |
+|             |           |              |
+|             |           |              |
+------------------------------------------
+....
+--
+* `layout = "MERGED"`
++
+--
+Only the `MERGED` buffer will be shown. Note, however, that all the other
+ones are still loaded in vim, and you can access them with the "buffers"
+command.
+....
+------------------------------------------
+|                                        |
+|                                        |
+|                 MERGED                 |
+|                                        |
+|                                        |
+------------------------------------------
+....
+--
+* `layout = "@LOCAL,REMOTE"`
++
+--
+When `MERGED` is not present in the layout, you must "mark" one of the
+buffers with an asterisk. That will become the buffer you need to edit and
+save after resolving the conflicts.
+....
+------------------------------------------
+|                   |                    |
+|                   |                    |
+|                   |                    |
+|     LOCAL         |    REMOTE          |
+|                   |                    |
+|                   |                    |
+|                   |                    |
+------------------------------------------
+....
+--
+* `layout = "LOCAL,BASE,REMOTE / MERGED + BASE,LOCAL + BASE,REMOTE"`
++
+--
+Three tabs will open: the first one is a copy of the default layout, while
+the other two only show the differences between (`BASE` and `LOCAL`) and
+(`BASE` and `REMOTE`) respectively.
+....
+------------------------------------------
+| <TAB #1> |  TAB #2  |  TAB #3  |       |
+------------------------------------------
+|             |           |              |
+|   LOCAL     |   BASE    |   REMOTE     |
+|             |           |              |
+------------------------------------------
+|                                        |
+|                MERGED                  |
+|                                        |
+------------------------------------------
+....
+....
+------------------------------------------
+|  TAB #1  | <TAB #2> |  TAB #3  |       |
+------------------------------------------
+|                   |                    |
+|                   |                    |
+|                   |                    |
+|     BASE          |    LOCAL           |
+|                   |                    |
+|                   |                    |
+|                   |                    |
+------------------------------------------
+....
+....
+------------------------------------------
+|  TAB #1  |  TAB #2  | <TAB #3> |       |
+------------------------------------------
+|                   |                    |
+|                   |                    |
+|                   |                    |
+|     BASE          |    REMOTE          |
+|                   |                    |
+|                   |                    |
+|                   |                    |
+------------------------------------------
+....
+--
+* `layout = "LOCAL,BASE,REMOTE / MERGED + BASE,LOCAL + BASE,REMOTE + (LOCAL/BASE/REMOTE),MERGED"`
++
+--
+Same as the previous example, but adds a fourth tab with the same
+information as the first tab, with a different layout.
+....
+---------------------------------------------
+|  TAB #1  |  TAB #2  |  TAB #3  | <TAB #4> |
+---------------------------------------------
+|       LOCAL         |                     |
+|---------------------|                     |
+|       BASE          |        MERGED       |
+|---------------------|                     |
+|       REMOTE        |                     |
+---------------------------------------------
+....
+Note how in the third tab definition we need to use parenthesis to make `,`
+have precedence over `/`.
+--
+
+Variants
+^^^^^^^^
+
+Instead of `--tool=vimdiff`, you can also use one of these other variants:
+
+  * `--tool=gvimdiff`, to open gVim instead of Vim.
+
+  * `--tool=nvimdiff`, to open Neovim instead of Vim.
+
+When using these variants, in order to specify a custom layout you will have to
+set configuration variables `mergetool.gvimdiff.layout` and
+`mergetool.nvimdiff.layout` instead of `mergetool.vimdiff.layout`
+
+In addition, for backwards compatibility with previous Git versions, you can
+also append `1`, `2` or `3` to either `vimdiff` or any of the variants (ex:
+`vimdiff3`, `nvimdiff1`, etc...) to use a predefined layout.
+In other words, using `--tool=[g,n,]vimdiffx` is the same as using
+`--tool=[g,n,]vimdiff` and setting configuration variable
+`mergetool.[g,n,]vimdiff.layout` to...
+
+  * `x=1`: `"@LOCAL, REMOTE"`
+  * `x=2`: `"LOCAL, MERGED, REMOTE"`
+  * `x=3`: `"MERGED"`
+
+Example: using `--tool=gvimdiff2` will open `gvim` with three columns (LOCAL,
+MERGED and REMOTE).

diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index 542a6a75eb3c4b93d8b4a394551d5d38d2a88f6e..9f99201bcca1eada84c3f19d1ca44cb41b3f3c59 100644 (file)
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -63,7 +63,7 @@ $(list_tool_variants)"
                                        preamble=
                                fi
                                shown_any=yes
-                               printf "%s%s\n" "$per_line_prefix" "$toolname"
+                               printf "%s%-15s  %s\n" "$per_line_prefix" "$toolname" $(diff_mode && diff_cmd_help "$toolname" || merge_cmd_help "$toolname")
                        fi
                done
 
@@ -162,10 +162,18 @@ setup_tool () {
                return 1
        }
 
+       diff_cmd_help () {
+               return 0
+       }
+
        merge_cmd () {
                return 1
        }
 
+       merge_cmd_help () {
+               return 0
+       }
+
        hide_resolved_enabled () {
                return 0
        }

diff --git a/mergetools/vimdiff b/mergetools/vimdiff
index 9d1bf4f455650d2deb7b72a41e7ad6d496476c50..461a89b6f987972c6447a1e6d8df074aedddf814 100644 (file)
--- a/mergetools/vimdiff
+++ b/mergetools/vimdiff
@@ -365,6 +365,25 @@ diff_cmd () {
 }
 
 
+diff_cmd_help () {
+       TOOL=$1
+
+       case "$TOOL" in
+       nvimdiff*)
+               printf "Use Neovim"
+               ;;
+       gvimdiff*)
+               printf "Use gVim (requires a graphical session)"
+               ;;
+       vimdiff*)
+               printf "Use Vim"
+               ;;
+       esac
+
+       return 0
+}
+
+
 merge_cmd () {
        layout=$(git config mergetool.vimdiff.layout)
 
@@ -436,6 +455,40 @@ merge_cmd () {
 }
 
 
+merge_cmd_help () {
+       TOOL=$1
+
+       case "$TOOL" in
+       nvimdiff*)
+               printf "Use Neovim "
+               ;;
+       gvimdiff*)
+               printf "Use gVim (requires a graphical session) "
+               ;;
+       vimdiff*)
+               printf "Use Vim "
+               ;;
+       esac
+
+       case "$TOOL" in
+       *1)
+               echo "with a 2 panes layout (LOCAL and REMOTE)"
+               ;;
+       *2)
+               echo "with a 3 panes layout (LOCAL, MERGED and REMOTE)"
+               ;;
+       *3)
+               echo "where only the MERGED file is shown"
+               ;;
+       *)
+               echo "with a custom layout (see \`git help mergetool\`'s \`BACKEND SPECIFIC HINTS\` section)"
+               ;;
+       esac
+
+       return 0
+}
+
+
 translate_merge_tool_path () {
        case "$1" in
        nvimdiff*)