Introduce support for the Meson build system

Makefile

@@ -8,6 +8,7 @@ gitk_libdir   ?= $(sharedir)/gitk/lib
 msgsdir    ?= $(gitk_libdir)/msgs
 msgsdir_SQ  = $(subst ','\'',$(msgsdir))
 
+SHELL_PATH ?= /bin/sh
 TCL_PATH ?= tclsh
 TCLTK_PATH ?= wish
 INSTALL ?= install
@@ -64,9 +65,7 @@ clean::
 
 gitk-wish: gitk GIT-TCLTK-VARS
 	$(QUIET_GEN)$(RM) $@ $@+ && \
-	sed -e '1,3s|^exec .* "$$0"|exec $(subst |,'\|',$(TCLTK_PATH_SQ)) "$$0"|' <gitk >$@+ && \
-	chmod +x $@+ && \
-	mv -f $@+ $@
+	$(SHELL_PATH) ./generate-tcl.sh "$(TCLTK_PATH_SQ)" "$<" "$@"
 
 $(PO_TEMPLATE): gitk
 	$(XGETTEXT) -kmc -LTcl -o $@ gitk

generate-tcl.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+set -e
+
+WISH=$(echo "$1" | sed 's/|/\\|/g')
+INPUT="$2"
+OUTPUT="$3"
+
+sed -e "1,3s|^exec .* \"\$0\"|exec $WISH \"\$0\"|" "$INPUT" >"$OUTPUT"+
+chmod a+x "$OUTPUT"+
+mv "$OUTPUT"+ "$OUTPUT"

meson.build

@@ -0,0 +1,30 @@
+project('gitk')
+
+shell = find_program('sh')
+wish = find_program('wish')
+
+# Verify that dependencies of "generate-tcl.sh" are satisfied.
+foreach dependency : [ 'chmod', 'mv', 'sed' ]
+  find_program(dependency)
+endforeach
+
+custom_target(
+  command: [
+    shell,
+    meson.current_source_dir() / 'generate-tcl.sh',
+    wish.full_path(),
+    '@INPUT@',
+    '@OUTPUT@',
+  ],
+  input: 'gitk',
+  output: 'gitk',
+  depend_files: [
+    'generate-tcl.sh',
+  ],
+  install: true,
+  install_dir: get_option('bindir'),
+)
+
+if find_program('msgfmt').found()
+  subdir('po')
+endif

po/meson.build

@@ -0,0 +1,19 @@
+import('i18n').gettext('gitk',
+  languages: [
+    'bg',
+    'ca',
+    'de',
+    'es',
+    'fr',
+    'hu',
+    'it',
+    'ja',
+    'pt_br',
+    'pt_pt',
+    'ru',
+    'sv',
+    'vi',
+    'zh_cn',
+  ],
+  install: true,
+)