daemon: Internationalize guix-daemon.

* nix/nix-daemon/guix-daemon.cc (n_, _): New macros.
  (guix_textdomain): New variable.
  (doc): Use 'n_'.
  (options): Likewise, and lowercase messages.
  (argp): Add initializer for 'argp_domain' field.
  (parse_opt): Use '_' for messages.
  (main): Likewise, and add calls to 'setlocale', 'bindtextdomain', and
  'textdomain'.
* daemon.am (guix_daemon_CPPFLAGS): Add -DLOCALEDIR.
* po/guix/Makevars (XGETTEXT_OPTIONS): Remove '--language' option.  Add
  '--keyword=n_'.
* po/guix/POTFILES.in: Add guix-daemon.cc.

4 files changed, 68 insertions, 43 deletions

diff --git a/daemon.am b/daemon.am
index 50b488923a..eecfea1c7e 100644
--- a/daemon.am
+++ b/daemon.am
@@ -126,6 +126,7 @@ guix_daemon_SOURCES =				\
   nix/nix-daemon/guix-daemon.cc
 
 guix_daemon_CPPFLAGS =				\
+  -DLOCALEDIR=\"$(localedir)\"			\
   $(libutil_a_CPPFLAGS)				\
   -I$(top_srcdir)/nix/libstore
 
diff --git a/nix/nix-daemon/guix-daemon.cc b/nix/nix-daemon/guix-daemon.cc
index 315744394f..1934487d24 100644
--- a/nix/nix-daemon/guix-daemon.cc
+++ b/nix/nix-daemon/guix-daemon.cc
@@ -33,6 +33,9 @@
 #include <strings.h>
 #include <exception>
 
+#include <libintl.h>
+#include <locale.h>
+
 /* Variables used by `nix-daemon.cc'.  */
 volatile ::sig_atomic_t blockInt;
 char **argvSaved;
@@ -45,16 +48,21 @@ extern void run (Strings args);
 
 /* Command-line options.  */
 
+#define n_(str)  str
+#define _(str)   gettext (str)
+static const char guix_textdomain[] = "guix";
+
+
 const char *argp_program_version =
   "guix-daemon (" PACKAGE_NAME ") " PACKAGE_VERSION;
 const char *argp_program_bug_address = PACKAGE_BUGREPORT;
 
 static char doc[] =
-"guix-daemon -- perform derivation builds and store accesses\
-\v\
-This program is a daemon meant to run in the background.  It serves \
+  n_("guix-daemon -- perform derivation builds and store accesses")
+  "\v\n"
+  n_("This program is a daemon meant to run in the background.  It serves \
 requests sent over a Unix-domain socket.  It accesses the store, and \
-builds derivations on behalf of its clients.";
+builds derivations on behalf of its clients.");
 
 #define GUIX_OPT_SYSTEM 1
 #define GUIX_OPT_DISABLE_CHROOT 2
@@ -75,56 +83,59 @@ builds derivations on behalf of its clients.";
 
 static const struct argp_option options[] =
   {
-    { "system", GUIX_OPT_SYSTEM, "SYSTEM", 0,
-      "Assume SYSTEM as the current system type" },
-    { "cores", 'c', "N", 0,
-      "Use N CPU cores to build each derivation; 0 means as many as available" },
-    { "max-jobs", 'M', "N", 0,
-      "Allow at most N build jobs" },
+    { "system", GUIX_OPT_SYSTEM, n_("SYSTEM"), 0,
+      n_("assume SYSTEM as the current system type") },
+    { "cores", 'c', n_("N"), 0,
+      n_("use N CPU cores to build each derivation; 0 means as many as available")
+    },
+    { "max-jobs", 'M', n_("N"), 0,
+      n_("allow at most N build jobs") },
     { "disable-chroot", GUIX_OPT_DISABLE_CHROOT, 0, 0,
-      "Disable chroot builds" },
-    { "chroot-directory", GUIX_OPT_CHROOT_DIR, "DIR", 0,
-      "Add DIR to the build chroot" },
-    { "build-users-group", GUIX_OPT_BUILD_USERS_GROUP, "GROUP", 0,
-      "Perform builds as a user of GROUP" },
+      n_("disable chroot builds") },
+    { "chroot-directory", GUIX_OPT_CHROOT_DIR, n_("DIR"), 0,
+      n_("add DIR to the build chroot") },
+    { "build-users-group", GUIX_OPT_BUILD_USERS_GROUP, n_("GROUP"), 0,
+      n_("perform builds as a user of GROUP") },
     { "no-substitutes", GUIX_OPT_NO_SUBSTITUTES, 0, 0,
-      "Do not use substitutes" },
-    { "substitute-urls", GUIX_OPT_SUBSTITUTE_URLS, "URLS", 0,
-      "Use URLS as the default list of substitute providers" },
+      n_("do not use substitutes") },
+    { "substitute-urls", GUIX_OPT_SUBSTITUTE_URLS, n_("URLS"), 0,
+      n_("use URLS as the default list of substitute providers") },
     { "no-build-hook", GUIX_OPT_NO_BUILD_HOOK, 0, 0,
-      "Do not use the 'build hook'" },
+      n_("do not use the 'build hook'") },
     { "cache-failures", GUIX_OPT_CACHE_FAILURES, 0, 0,
-      "Cache build failures" },
+      n_("cache build failures") },
     { "lose-logs", GUIX_OPT_LOSE_LOGS, 0, 0,
-      "Do not keep build logs" },
+      n_("do not keep build logs") },
     { "disable-log-compression", GUIX_OPT_DISABLE_LOG_COMPRESSION, 0, 0,
-      "Disable compression of the build logs" },
+      n_("disable compression of the build logs") },
 
     /* '--disable-deduplication' was known as '--disable-store-optimization'
        up to Guix 0.7 included, so keep the alias around.  */
     { "disable-deduplication", GUIX_OPT_DISABLE_DEDUPLICATION, 0, 0,
-      "Disable automatic file \"deduplication\" in the store" },
+      n_("disable automatic file \"deduplication\" in the store") },
     { "disable-store-optimization", GUIX_OPT_DISABLE_DEDUPLICATION, 0,
       OPTION_ALIAS | OPTION_HIDDEN, NULL },
 
-    { "impersonate-linux-2.6", GUIX_OPT_IMPERSONATE_LINUX_26, 0, 0,
-      "Impersonate Linux 2.6"
-#ifndef HAVE_SYS_PERSONALITY_H
-      " (this option has no effect in this configuration)"
+    { "impersonate-linux-2.6", GUIX_OPT_IMPERSONATE_LINUX_26, 0,
+#ifdef HAVE_SYS_PERSONALITY_H
+      0,
+#else
+      OPTION_HIDDEN,
 #endif
+      n_("impersonate Linux 2.6")
     },
     { "gc-keep-outputs", GUIX_OPT_GC_KEEP_OUTPUTS,
       "yes/no", OPTION_ARG_OPTIONAL,
-      "Tell whether the GC must keep outputs of live derivations" },
+      n_("tell whether the GC must keep outputs of live derivations") },
     { "gc-keep-derivations", GUIX_OPT_GC_KEEP_DERIVATIONS,
       "yes/no", OPTION_ARG_OPTIONAL,
-      "Tell whether the GC must keep derivations corresponding \
-to live outputs" },
+      n_("tell whether the GC must keep derivations corresponding \
+to live outputs") },
 
-    { "listen", GUIX_OPT_LISTEN, "SOCKET", 0,
-      "Listen for connections on SOCKET" },
+    { "listen", GUIX_OPT_LISTEN, n_("SOCKET"), 0,
+      n_("listen for connections on SOCKET") },
     { "debug", GUIX_OPT_DEBUG, 0, 0,
-      "Produce debugging output" },
+      n_("produce debugging output") },
     { 0, 0, 0, 0, 0 }
   };
 
@@ -191,7 +202,7 @@ parse_opt (int key, char *arg, struct argp_state *state)
 	}
       catch (std::exception &e)
 	{
-	  fprintf (stderr, "error: %s\n", e.what ());
+	  fprintf (stderr, _("error: %s\n"), e.what ());
 	  exit (EXIT_FAILURE);
 	}
       break;
@@ -230,19 +241,29 @@ parse_opt (int key, char *arg, struct argp_state *state)
 }
 
 /* Argument parsing.  */
-static struct argp argp = { options, parse_opt, 0, doc };
+static const struct argp argp =
+  {
+    options, parse_opt,
+    NULL, doc,
+    NULL, NULL,					  // children and help_filter
+    guix_textdomain
+  };
 
 
 
 int
 main (int argc, char *argv[])
 {
-  Strings nothing;
+  static const Strings nothing;
+
+  setlocale (LC_ALL, "");
+  bindtextdomain (guix_textdomain, LOCALEDIR);
+  textdomain (guix_textdomain);
 
   /* Initialize libgcrypt.  */
   if (!gcry_check_version (GCRYPT_VERSION))
     {
-      fprintf (stderr, "error: libgcrypt version mismatch\n");
+      fprintf (stderr, _("error: libgcrypt version mismatch\n"));
       exit (EXIT_FAILURE);
     }
 
@@ -333,8 +354,8 @@ main (int argc, char *argv[])
       settings.update ();
 
       if (geteuid () == 0 && settings.buildUsersGroup.empty ())
-	fprintf (stderr, "warning: daemon is running as root, so "
-		 "using `--build-users-group' is highly recommended\n");
+	fprintf (stderr, _("warning: daemon is running as root, so \
+using `--build-users-group' is highly recommended\n"));
 
       if (settings.useChroot)
 	{
@@ -357,7 +378,7 @@ main (int argc, char *argv[])
     }
   catch (std::exception &e)
     {
-      fprintf (stderr, "error: %s\n", e.what ());
+      fprintf (stderr, _("error: %s\n"), e.what ());
       return EXIT_FAILURE;
     }
 
diff --git a/po/guix/Makevars b/po/guix/Makevars
index 9c5965a136..8ec7d8aed6 100644
--- a/po/guix/Makevars
+++ b/po/guix/Makevars
@@ -6,12 +6,14 @@ subdir = po/guix
 top_builddir = ../..
 
 # These options get passed to xgettext.  We want to catch standard
-# gettext uses, and SRFI-35 error condition messages.
+# gettext uses, and SRFI-35 error condition messages.  In C++ code
+# we use 'n_' instead of the more usual 'N_' for no-ops.
 XGETTEXT_OPTIONS =				\
-  --language=Scheme --from-code=UTF-8		\
+  --from-code=UTF-8				\
   --keyword=_ --keyword=N_:1,2			\
   --keyword=message				\
-  --keyword=description
+  --keyword=description				\
+  --keyword=n_
 
 COPYRIGHT_HOLDER = Ludovic Courtès
 
diff --git a/po/guix/POTFILES.in b/po/guix/POTFILES.in
index 59f353e427..4f27f54d6c 100644
--- a/po/guix/POTFILES.in
+++ b/po/guix/POTFILES.in
@@ -20,3 +20,4 @@ guix/gnu-maintenance.scm
 guix/ui.scm
 guix/http-client.scm
 guix/nar.scm
+nix/nix-daemon/guix-daemon.cc