git-mergetool--lib.shon commit t/README: justify why "! grep foo" is sufficient (53de742)
   1#!/bin/sh
   2# git-mergetool--lib is a library for common merge tool functions
   3
   4: ${MERGE_TOOLS_DIR=$(git --exec-path)/mergetools}
   5
   6mode_ok () {
   7        if diff_mode
   8        then
   9                can_diff
  10        elif merge_mode
  11        then
  12                can_merge
  13        else
  14                false
  15        fi
  16}
  17
  18is_available () {
  19        merge_tool_path=$(translate_merge_tool_path "$1") &&
  20        type "$merge_tool_path" >/dev/null 2>&1
  21}
  22
  23list_config_tools () {
  24        section=$1
  25        line_prefix=${2:-}
  26
  27        git config --get-regexp $section'\..*\.cmd' |
  28        while read -r key value
  29        do
  30                toolname=${key#$section.}
  31                toolname=${toolname%.cmd}
  32
  33                printf "%s%s\n" "$line_prefix" "$toolname"
  34        done
  35}
  36
  37show_tool_names () {
  38        condition=${1:-true} per_line_prefix=${2:-} preamble=${3:-}
  39        not_found_msg=${4:-}
  40        extra_content=${5:-}
  41
  42        shown_any=
  43        ( cd "$MERGE_TOOLS_DIR" && ls ) | {
  44                while read toolname
  45                do
  46                        if setup_tool "$toolname" 2>/dev/null &&
  47                                (eval "$condition" "$toolname")
  48                        then
  49                                if test -n "$preamble"
  50                                then
  51                                        printf "%s\n" "$preamble"
  52                                        preamble=
  53                                fi
  54                                shown_any=yes
  55                                printf "%s%s\n" "$per_line_prefix" "$toolname"
  56                        fi
  57                done
  58
  59                if test -n "$extra_content"
  60                then
  61                        if test -n "$preamble"
  62                        then
  63                                # Note: no '\n' here since we don't want a
  64                                # blank line if there is no initial content.
  65                                printf "%s" "$preamble"
  66                                preamble=
  67                        fi
  68                        shown_any=yes
  69                        printf "\n%s\n" "$extra_content"
  70                fi
  71
  72                if test -n "$preamble" && test -n "$not_found_msg"
  73                then
  74                        printf "%s\n" "$not_found_msg"
  75                fi
  76
  77                test -n "$shown_any"
  78        }
  79}
  80
  81diff_mode() {
  82        test "$TOOL_MODE" = diff
  83}
  84
  85merge_mode() {
  86        test "$TOOL_MODE" = merge
  87}
  88
  89translate_merge_tool_path () {
  90        echo "$1"
  91}
  92
  93check_unchanged () {
  94        if test "$MERGED" -nt "$BACKUP"
  95        then
  96                status=0
  97        else
  98                while true
  99                do
 100                        echo "$MERGED seems unchanged."
 101                        printf "Was the merge successful? [y/n] "
 102                        read answer || return 1
 103                        case "$answer" in
 104                        y*|Y*) status=0; break ;;
 105                        n*|N*) status=1; break ;;
 106                        esac
 107                done
 108        fi
 109}
 110
 111valid_tool () {
 112        setup_tool "$1" && return 0
 113        cmd=$(get_merge_tool_cmd "$1")
 114        test -n "$cmd"
 115}
 116
 117setup_user_tool () {
 118        merge_tool_cmd=$(get_merge_tool_cmd "$tool")
 119        test -n "$merge_tool_cmd" || return 1
 120
 121        diff_cmd () {
 122                ( eval $merge_tool_cmd )
 123                status=$?
 124                return $status
 125        }
 126
 127        merge_cmd () {
 128                trust_exit_code=$(git config --bool \
 129                        "mergetool.$1.trustExitCode" || echo false)
 130                if test "$trust_exit_code" = "false"
 131                then
 132                        touch "$BACKUP"
 133                        ( eval $merge_tool_cmd )
 134                        status=$?
 135                        check_unchanged
 136                else
 137                        ( eval $merge_tool_cmd )
 138                        status=$?
 139                fi
 140                return $status
 141        }
 142}
 143
 144setup_tool () {
 145        tool="$1"
 146
 147        # Fallback definitions, to be overridden by tools.
 148        can_merge () {
 149                return 0
 150        }
 151
 152        can_diff () {
 153                return 0
 154        }
 155
 156        diff_cmd () {
 157                status=1
 158                return $status
 159        }
 160
 161        merge_cmd () {
 162                status=1
 163                return $status
 164        }
 165
 166        translate_merge_tool_path () {
 167                echo "$1"
 168        }
 169
 170        if ! test -f "$MERGE_TOOLS_DIR/$tool"
 171        then
 172                setup_user_tool
 173                return $?
 174        fi
 175
 176        # Load the redefined functions
 177        . "$MERGE_TOOLS_DIR/$tool"
 178        # Now let the user override the default command for the tool.  If
 179        # they have not done so then this will return 1 which we ignore.
 180        setup_user_tool
 181
 182        if merge_mode && ! can_merge
 183        then
 184                echo "error: '$tool' can not be used to resolve merges" >&2
 185                return 1
 186        elif diff_mode && ! can_diff
 187        then
 188                echo "error: '$tool' can only be used to resolve merges" >&2
 189                return 1
 190        fi
 191        return 0
 192}
 193
 194get_merge_tool_cmd () {
 195        merge_tool="$1"
 196        if diff_mode
 197        then
 198                git config "difftool.$merge_tool.cmd" ||
 199                git config "mergetool.$merge_tool.cmd"
 200        else
 201                git config "mergetool.$merge_tool.cmd"
 202        fi
 203}
 204
 205# Entry point for running tools
 206run_merge_tool () {
 207        # If GIT_PREFIX is empty then we cannot use it in tools
 208        # that expect to be able to chdir() to its value.
 209        GIT_PREFIX=${GIT_PREFIX:-.}
 210        export GIT_PREFIX
 211
 212        merge_tool_path=$(get_merge_tool_path "$1") || exit
 213        base_present="$2"
 214        status=0
 215
 216        # Bring tool-specific functions into scope
 217        setup_tool "$1" || return 1
 218
 219        if merge_mode
 220        then
 221                run_merge_cmd "$1"
 222        else
 223                run_diff_cmd "$1"
 224        fi
 225        return $status
 226}
 227
 228# Run a either a configured or built-in diff tool
 229run_diff_cmd () {
 230        diff_cmd "$1"
 231}
 232
 233# Run a either a configured or built-in merge tool
 234run_merge_cmd () {
 235        merge_cmd "$1"
 236}
 237
 238list_merge_tool_candidates () {
 239        if merge_mode
 240        then
 241                tools="tortoisemerge"
 242        else
 243                tools="kompare"
 244        fi
 245        if test -n "$DISPLAY"
 246        then
 247                if test -n "$GNOME_DESKTOP_SESSION_ID"
 248                then
 249                        tools="meld opendiff kdiff3 tkdiff xxdiff $tools"
 250                else
 251                        tools="opendiff kdiff3 tkdiff xxdiff meld $tools"
 252                fi
 253                tools="$tools gvimdiff diffuse diffmerge ecmerge"
 254                tools="$tools p4merge araxis bc3 codecompare"
 255        fi
 256        case "${VISUAL:-$EDITOR}" in
 257        *vim*)
 258                tools="$tools vimdiff emerge"
 259                ;;
 260        *)
 261                tools="$tools emerge vimdiff"
 262                ;;
 263        esac
 264}
 265
 266show_tool_help () {
 267        tool_opt="'git ${TOOL_MODE}tool --tool=<tool>'"
 268
 269        tab='   '
 270        LF='
 271'
 272        any_shown=no
 273
 274        cmd_name=${TOOL_MODE}tool
 275        config_tools=$({
 276                diff_mode && list_config_tools difftool "$tab$tab"
 277                list_config_tools mergetool "$tab$tab"
 278        } | sort)
 279        extra_content=
 280        if test -n "$config_tools"
 281        then
 282                extra_content="${tab}user-defined:${LF}$config_tools"
 283        fi
 284
 285        show_tool_names 'mode_ok && is_available' "$tab$tab" \
 286                "$tool_opt may be set to one of the following:" \
 287                "No suitable tool for 'git $cmd_name --tool=<tool>' found." \
 288                "$extra_content" &&
 289                any_shown=yes
 290
 291        show_tool_names 'mode_ok && ! is_available' "$tab$tab" \
 292                "${LF}The following tools are valid, but not currently available:" &&
 293                any_shown=yes
 294
 295        if test "$any_shown" = yes
 296        then
 297                echo
 298                echo "Some of the tools listed above only work in a windowed"
 299                echo "environment. If run in a terminal-only session, they will fail."
 300        fi
 301        exit 0
 302}
 303
 304guess_merge_tool () {
 305        list_merge_tool_candidates
 306        cat >&2 <<-EOF
 307
 308        This message is displayed because '$TOOL_MODE.tool' is not configured.
 309        See 'git ${TOOL_MODE}tool --tool-help' or 'git help config' for more details.
 310        'git ${TOOL_MODE}tool' will now attempt to use one of the following tools:
 311        $tools
 312        EOF
 313
 314        # Loop over each candidate and stop when a valid merge tool is found.
 315        for tool in $tools
 316        do
 317                is_available "$tool" && echo "$tool" && return 0
 318        done
 319
 320        echo >&2 "No known ${TOOL_MODE} tool is available."
 321        return 1
 322}
 323
 324get_configured_merge_tool () {
 325        # Diff mode first tries diff.tool and falls back to merge.tool.
 326        # Merge mode only checks merge.tool
 327        if diff_mode
 328        then
 329                merge_tool=$(git config diff.tool || git config merge.tool)
 330        else
 331                merge_tool=$(git config merge.tool)
 332        fi
 333        if test -n "$merge_tool" && ! valid_tool "$merge_tool"
 334        then
 335                echo >&2 "git config option $TOOL_MODE.tool set to unknown tool: $merge_tool"
 336                echo >&2 "Resetting to default..."
 337                return 1
 338        fi
 339        echo "$merge_tool"
 340}
 341
 342get_merge_tool_path () {
 343        # A merge tool has been set, so verify that it's valid.
 344        merge_tool="$1"
 345        if ! valid_tool "$merge_tool"
 346        then
 347                echo >&2 "Unknown merge tool $merge_tool"
 348                exit 1
 349        fi
 350        if diff_mode
 351        then
 352                merge_tool_path=$(git config difftool."$merge_tool".path ||
 353                                  git config mergetool."$merge_tool".path)
 354        else
 355                merge_tool_path=$(git config mergetool."$merge_tool".path)
 356        fi
 357        if test -z "$merge_tool_path"
 358        then
 359                merge_tool_path=$(translate_merge_tool_path "$merge_tool")
 360        fi
 361        if test -z "$(get_merge_tool_cmd "$merge_tool")" &&
 362                ! type "$merge_tool_path" >/dev/null 2>&1
 363        then
 364                echo >&2 "The $TOOL_MODE tool $merge_tool is not available as"\
 365                         "'$merge_tool_path'"
 366                exit 1
 367        fi
 368        echo "$merge_tool_path"
 369}
 370
 371get_merge_tool () {
 372        # Check if a merge tool has been configured
 373        merge_tool=$(get_configured_merge_tool)
 374        # Try to guess an appropriate merge tool if no tool has been set.
 375        if test -z "$merge_tool"
 376        then
 377                merge_tool=$(guess_merge_tool) || exit
 378        fi
 379        echo "$merge_tool"
 380}