git-mergetool--lib.sh

   1 # git-mergetool--lib is a shell library for common merge tool functions
   2
   3 : ${MERGE_TOOLS_DIR=$(git --exec-path)/mergetools}
   4
   5 IFS='
   6 '
   7
   8 mode_ok () {
   9         if diff_mode
  10         then
  11                 can_diff
  12         elif merge_mode
  13         then
  14                 can_merge
  15         else
  16                 false
  17         fi
  18 }
  19
  20 is_available () {
  21         merge_tool_path=$(translate_merge_tool_path "$1") &&
  22         type "$merge_tool_path" >/dev/null 2>&1
  23 }
  24
  25 list_config_tools () {
  26         section=$1
  27         line_prefix=${2:-}
  28
  29         git config --get-regexp $section'\..*\.cmd' |
  30         while read -r key value
  31         do
  32                 toolname=${key#$section.}
  33                 toolname=${toolname%.cmd}
  34
  35                 printf "%s%s\n" "$line_prefix" "$toolname"
  36         done
  37 }
  38
  39 show_tool_names () {
  40         condition=${1:-true} per_line_prefix=${2:-} preamble=${3:-}
  41         not_found_msg=${4:-}
  42         extra_content=${5:-}
  43
  44         shown_any=
  45         ( cd "$MERGE_TOOLS_DIR" && ls ) | {
  46                 while read scriptname
  47                 do
  48                         setup_tool "$scriptname" 2>/dev/null
  49                         # We need an actual line feed here
  50                         variants="$variants
  51 $(list_tool_variants)"
  52                 done
  53                 variants="$(echo "$variants" | sort -u)"
  54
  55                 for toolname in $variants
  56                 do
  57                         if setup_tool "$toolname" 2>/dev/null &&
  58                                 (eval "$condition" "$toolname")
  59                         then
  60                                 if test -n "$preamble"
  61                                 then
  62                                         printf "%s\n" "$preamble"
  63                                         preamble=
  64                                 fi
  65                                 shown_any=yes
  66                                 printf "%s%s\n" "$per_line_prefix" "$toolname"
  67                         fi
  68                 done
  69
  70                 if test -n "$extra_content"
  71                 then
  72                         if test -n "$preamble"
  73                         then
  74                                 # Note: no '\n' here since we don't want a
  75                                 # blank line if there is no initial content.
  76                                 printf "%s" "$preamble"
  77                                 preamble=
  78                         fi
  79                         shown_any=yes
  80                         printf "\n%s\n" "$extra_content"
  81                 fi
  82
  83                 if test -n "$preamble" && test -n "$not_found_msg"
  84                 then
  85                         printf "%s\n" "$not_found_msg"
  86                 fi
  87
  88                 test -n "$shown_any"
  89         }
  90 }
  91
  92 diff_mode () {
  93         test "$TOOL_MODE" = diff
  94 }
  95
  96 merge_mode () {
  97         test "$TOOL_MODE" = merge
  98 }
  99
 100 gui_mode () {
 101         test "$GIT_MERGETOOL_GUI" = true
 102 }
 103
 104 translate_merge_tool_path () {
 105         echo "$1"
 106 }
 107
 108 check_unchanged () {
 109         if test "$MERGED" -nt "$BACKUP"
 110         then
 111                 return 0
 112         else
 113                 while true
 114                 do
 115                         echo "$MERGED seems unchanged."
 116                         printf "Was the merge successful [y/n]? "
 117                         read answer || return 1
 118                         case "$answer" in
 119                         y*|Y*) return 0 ;;
 120                         n*|N*) return 1 ;;
 121                         esac
 122                 done
 123         fi
 124 }
 125
 126 valid_tool () {
 127         setup_tool "$1" && return 0
 128         cmd=$(get_merge_tool_cmd "$1")
 129         test -n "$cmd"
 130 }
 131
 132 setup_user_tool () {
 133         merge_tool_cmd=$(get_merge_tool_cmd "$tool")
 134         test -n "$merge_tool_cmd" || return 1
 135
 136         diff_cmd () {
 137                 ( eval $merge_tool_cmd )
 138         }
 139
 140         merge_cmd () {
 141                 ( eval $merge_tool_cmd )
 142         }
 143
 144         list_tool_variants () {
 145                 echo "$tool"
 146         }
 147 }
 148
 149 setup_tool () {
 150         tool="$1"
 151
 152         # Fallback definitions, to be overridden by tools.
 153         can_merge () {
 154                 return 0
 155         }
 156
 157         can_diff () {
 158                 return 0
 159         }
 160
 161         diff_cmd () {
 162                 return 1
 163         }
 164
 165         merge_cmd () {
 166                 return 1
 167         }
 168
 169         translate_merge_tool_path () {
 170                 echo "$1"
 171         }
 172
 173         list_tool_variants () {
 174                 echo "$tool"
 175         }
 176
 177         # Most tools' exit codes cannot be trusted, so By default we ignore
 178         # their exit code and check the merged file's modification time in
 179         # check_unchanged() to determine whether or not the merge was
 180         # successful.  The return value from run_merge_cmd, by default, is
 181         # determined by check_unchanged().
 182         #
 183         # When a tool's exit code can be trusted then the return value from
 184         # run_merge_cmd is simply the tool's exit code, and check_unchanged()
 185         # is not called.
 186         #
 187         # The return value of exit_code_trustable() tells us whether or not we
 188         # can trust the tool's exit code.
 189         #
 190         # User-defined and built-in tools default to false.
 191         # Built-in tools advertise that their exit code is trustable by
 192         # redefining exit_code_trustable() to true.
 193
 194         exit_code_trustable () {
 195                 false
 196         }
 197
 198         if test -f "$MERGE_TOOLS_DIR/$tool"
 199         then
 200                 . "$MERGE_TOOLS_DIR/$tool"
 201         elif test -f "$MERGE_TOOLS_DIR/${tool%[0-9]}"
 202         then
 203                 . "$MERGE_TOOLS_DIR/${tool%[0-9]}"
 204         else
 205                 setup_user_tool
 206                 return $?
 207         fi
 208
 209         # Now let the user override the default command for the tool.  If
 210         # they have not done so then this will return 1 which we ignore.
 211         setup_user_tool
 212
 213         if ! list_tool_variants | grep -q "^$tool$"
 214         then
 215                 return 1
 216         fi
 217
 218         if merge_mode && ! can_merge
 219         then
 220                 echo "error: '$tool' can not be used to resolve merges" >&2
 221                 return 1
 222         elif diff_mode && ! can_diff
 223         then
 224                 echo "error: '$tool' can only be used to resolve merges" >&2
 225                 return 1
 226         fi
 227         return 0
 228 }
 229
 230 get_merge_tool_cmd () {
 231         merge_tool="$1"
 232         if diff_mode
 233         then
 234                 git config "difftool.$merge_tool.cmd" ||
 235                 git config "mergetool.$merge_tool.cmd"
 236         else
 237                 git config "mergetool.$merge_tool.cmd"
 238         fi
 239 }
 240
 241 trust_exit_code () {
 242         if git config --bool "mergetool.$1.trustExitCode"
 243         then
 244                 :; # OK
 245         elif exit_code_trustable
 246         then
 247                 echo true
 248         else
 249                 echo false
 250         fi
 251 }
 252
 253
 254 # Entry point for running tools
 255 run_merge_tool () {
 256         # If GIT_PREFIX is empty then we cannot use it in tools
 257         # that expect to be able to chdir() to its value.
 258         GIT_PREFIX=${GIT_PREFIX:-.}
 259         export GIT_PREFIX
 260
 261         merge_tool_path=$(get_merge_tool_path "$1") || exit
 262         base_present="$2"
 263
 264         # Bring tool-specific functions into scope
 265         setup_tool "$1" || return 1
 266
 267         if merge_mode
 268         then
 269                 run_merge_cmd "$1"
 270         else
 271                 run_diff_cmd "$1"
 272         fi
 273 }
 274
 275 # Run a either a configured or built-in diff tool
 276 run_diff_cmd () {
 277         diff_cmd "$1"
 278 }
 279
 280 # Run a either a configured or built-in merge tool
 281 run_merge_cmd () {
 282         mergetool_trust_exit_code=$(trust_exit_code "$1")
 283         if test "$mergetool_trust_exit_code" = "true"
 284         then
 285                 merge_cmd "$1"
 286         else
 287                 touch "$BACKUP"
 288                 merge_cmd "$1"
 289                 check_unchanged
 290         fi
 291 }
 292
 293 list_merge_tool_candidates () {
 294         if merge_mode
 295         then
 296                 tools="tortoisemerge"
 297         else
 298                 tools="kompare"
 299         fi
 300         if test -n "$DISPLAY"
 301         then
 302                 if test -n "$GNOME_DESKTOP_SESSION_ID"
 303                 then
 304                         tools="meld opendiff kdiff3 tkdiff xxdiff $tools"
 305                 else
 306                         tools="opendiff kdiff3 tkdiff xxdiff meld $tools"
 307                 fi
 308                 tools="$tools gvimdiff diffuse diffmerge ecmerge"
 309                 tools="$tools p4merge araxis bc codecompare"
 310                 tools="$tools smerge"
 311         fi
 312         case "${VISUAL:-$EDITOR}" in
 313         *nvim*)
 314                 tools="$tools nvimdiff vimdiff emerge"
 315                 ;;
 316         *vim*)
 317                 tools="$tools vimdiff nvimdiff emerge"
 318                 ;;
 319         *)
 320                 tools="$tools emerge vimdiff nvimdiff"
 321                 ;;
 322         esac
 323 }
 324
 325 show_tool_help () {
 326         tool_opt="'git ${TOOL_MODE}tool --tool=<tool>'"
 327
 328         tab='   '
 329         LF='
 330 '
 331         any_shown=no
 332
 333         cmd_name=${TOOL_MODE}tool
 334         config_tools=$({
 335                 diff_mode && list_config_tools difftool "$tab$tab"
 336                 list_config_tools mergetool "$tab$tab"
 337         } | sort)
 338         extra_content=
 339         if test -n "$config_tools"
 340         then
 341                 extra_content="${tab}user-defined:${LF}$config_tools"
 342         fi
 343
 344         show_tool_names 'mode_ok && is_available' "$tab$tab" \
 345                 "$tool_opt may be set to one of the following:" \
 346                 "No suitable tool for 'git $cmd_name --tool=<tool>' found." \
 347                 "$extra_content" &&
 348                 any_shown=yes
 349
 350         show_tool_names 'mode_ok && ! is_available' "$tab$tab" \
 351                 "${LF}The following tools are valid, but not currently available:" &&
 352                 any_shown=yes
 353
 354         if test "$any_shown" = yes
 355         then
 356                 echo
 357                 echo "Some of the tools listed above only work in a windowed"
 358                 echo "environment. If run in a terminal-only session, they will fail."
 359         fi
 360         exit 0
 361 }
 362
 363 guess_merge_tool () {
 364         list_merge_tool_candidates
 365         cat >&2 <<-EOF
 366
 367         This message is displayed because '$TOOL_MODE.tool' is not configured.
 368         See 'git ${TOOL_MODE}tool --tool-help' or 'git help config' for more details.
 369         'git ${TOOL_MODE}tool' will now attempt to use one of the following tools:
 370         $tools
 371         EOF
 372
 373         # Loop over each candidate and stop when a valid merge tool is found.
 374         IFS=' '
 375         for tool in $tools
 376         do
 377                 is_available "$tool" && echo "$tool" && return 0
 378         done
 379
 380         echo >&2 "No known ${TOOL_MODE} tool is available."
 381         return 1
 382 }
 383
 384 get_configured_merge_tool () {
 385         keys=
 386         if diff_mode
 387         then
 388                 if gui_mode
 389                 then
 390                         keys="diff.guitool merge.guitool diff.tool merge.tool"
 391                 else
 392                         keys="diff.tool merge.tool"
 393                 fi
 394         else
 395                 if gui_mode
 396                 then
 397                         keys="merge.guitool merge.tool"
 398                 else
 399                         keys="merge.tool"
 400                 fi
 401         fi
 402
 403         merge_tool=$(
 404                 IFS=' '
 405                 for key in $keys
 406                 do
 407                         selected=$(git config $key)
 408                         if test -n "$selected"
 409                         then
 410                                 echo "$selected"
 411                                 return
 412                         fi
 413                 done)
 414
 415         if test -n "$merge_tool" && ! valid_tool "$merge_tool"
 416         then
 417                 echo >&2 "git config option $TOOL_MODE.${gui_prefix}tool set to unknown tool: $merge_tool"
 418                 echo >&2 "Resetting to default..."
 419                 return 1
 420         fi
 421         echo "$merge_tool"
 422 }
 423
 424 get_merge_tool_path () {
 425         # A merge tool has been set, so verify that it's valid.
 426         merge_tool="$1"
 427         if ! valid_tool "$merge_tool"
 428         then
 429                 echo >&2 "Unknown merge tool $merge_tool"
 430                 exit 1
 431         fi
 432         if diff_mode
 433         then
 434                 merge_tool_path=$(git config difftool."$merge_tool".path ||
 435                                   git config mergetool."$merge_tool".path)
 436         else
 437                 merge_tool_path=$(git config mergetool."$merge_tool".path)
 438         fi
 439         if test -z "$merge_tool_path"
 440         then
 441                 merge_tool_path=$(translate_merge_tool_path "$merge_tool")
 442         fi
 443         if test -z "$(get_merge_tool_cmd "$merge_tool")" &&
 444                 ! type "$merge_tool_path" >/dev/null 2>&1
 445         then
 446                 echo >&2 "The $TOOL_MODE tool $merge_tool is not available as"\
 447                          "'$merge_tool_path'"
 448                 exit 1
 449         fi
 450         echo "$merge_tool_path"
 451 }
 452
 453 get_merge_tool () {
 454         is_guessed=false
 455         # Check if a merge tool has been configured
 456         merge_tool=$(get_configured_merge_tool)
 457         # Try to guess an appropriate merge tool if no tool has been set.
 458         if test -z "$merge_tool"
 459         then
 460                 merge_tool=$(guess_merge_tool) || exit
 461                 is_guessed=true
 462         fi
 463         echo "$merge_tool"
 464         test "$is_guessed" = false
 465 }
 466
 467 mergetool_find_win32_cmd () {
 468         executable=$1
 469         sub_directory=$2
 470
 471         # Use $executable if it exists in $PATH
 472         if type -p "$executable" >/dev/null 2>&1
 473         then
 474                 printf '%s' "$executable"
 475                 return
 476         fi
 477
 478         # Look for executable in the typical locations
 479         for directory in $(env | grep -Ei '^PROGRAM(FILES(\(X86\))?|W6432)=' |
 480                 cut -d '=' -f 2- | sort -u)
 481         do
 482                 if test -n "$directory" && test -x "$directory/$sub_directory/$executable"
 483                 then
 484                         printf '%s' "$directory/$sub_directory/$executable"
 485                         return
 486                 fi
 487         done
 488
 489         printf '%s' "$executable"
 490 }