localedef: Add verbose messages for failure paths.

During testing of localedef running in a minimal container
there were several error cases which were hard to diagnose
since they appeared as strerror (errno) values printed by the
higher level functions.  This change adds three new verbose
messages for potential failure paths.  The new messages give
the user the opportunity to use -v and display additional
information about why localedef might be failing.  I found
these messages useful myself while writing a localedef
container test for --no-hard-links.

Since the changes cleanup the code that handle codeset
normalization we add tst-localedef-path-norm which contains
many sub-tests to verify the correct expected normalization of
codeset strings both when installing to default paths (the
only time normalization is enabled) and installing to absolute
paths.  During the refactoring I created at least one
buffer-overflow which valgrind caught, but these tests did not
catch because the exec in the container had a very clean heap
with zero-initialized memory. However, between valgrind and
the tests the results are clean.

The new tst-localedef-path-norm passes without regression on
x86_64.

Change-Id: I28b9f680711ff00252a2cb15625b774cc58ecb9d

11 files changed, 394 insertions, 75 deletions

diff --git a/include/programs/xasprintf.h b/include/programs/xasprintf.h
new file mode 100644
index 0000000..53193ba
--- /dev/null
+++ b/include/programs/xasprintf.h
@@ -0,0 +1,24 @@
+/* asprintf with out of memory checking
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published
+   by the Free Software Foundation; version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
+
+#ifndef _XASPRINTF_H
+#define _XASPRINTF_H	1
+
+extern char *xasprintf (const char *format, ...)
+    __attribute__ ((__format__ (__printf__, 1, 2), __warn_unused_result__));
+
+#endif /* xasprintf.h */
diff --git a/locale/Makefile b/locale/Makefile
index c9694e2..49c0c78 100644
--- a/locale/Makefile
+++ b/locale/Makefile
@@ -28,6 +28,7 @@ routines	= setlocale findlocale loadlocale loadarchive \
 		  localeconv nl_langinfo nl_langinfo_l mb_cur_max \
 		  newlocale duplocale freelocale uselocale
 tests		= tst-C-locale tst-locname tst-duplocale
+tests-container	= tst-localedef-path-norm
 categories	= ctype messages monetary numeric time paper name \
 		  address telephone measurement identification collate
 aux		= $(categories:%=lc-%) $(categories:%=C-%) SYS_libc C_name \
@@ -56,7 +57,7 @@ localedef-modules	:= localedef $(categories:%=ld-%) \
 localedef-aux		:= md5
 locale-modules		:= locale locale-spec
 lib-modules		:= charmap-dir simple-hash xmalloc xstrdup \
-			   record-status
+			   record-status xasprintf
 
 
 GPERF = gperf
diff --git a/locale/programs/localedef.c b/locale/programs/localedef.c
index dbbb014..b048bd0 100644
--- a/locale/programs/localedef.c
+++ b/locale/programs/localedef.c
@@ -180,14 +180,14 @@ static struct argp argp =
 
 /* Prototypes for local functions.  */
 static void error_print (void);
-static const char *construct_output_path (char *path);
-static const char *normalize_codeset (const char *codeset, size_t name_len);
+static char *construct_output_path (char *path);
+static char *normalize_codeset (const char *codeset, size_t name_len);
 
 
 int
 main (int argc, char *argv[])
 {
-  const char *output_path;
+  char *output_path;
   int cannot_write_why;
   struct charmap_t *charmap;
   struct localedef_t global;
@@ -232,7 +232,8 @@ main (int argc, char *argv[])
     }
 
   /* The parameter describes the output path of the constructed files.
-     If the described files cannot be written return a NULL pointer.  */
+     If the described files cannot be written return a NULL pointer.
+     We don't free output_path because we will exit.  */
   output_path  = construct_output_path (argv[remaining]);
   if (output_path == NULL && ! no_archive)
     error (4, errno, _("cannot create directory for output files"));
@@ -434,20 +435,16 @@ more_help (int key, const char *text, void *input)
     {
     case ARGP_KEY_HELP_EXTRA:
       /* We print some extra information.  */
-      if (asprintf (&tp, gettext ("\
+      tp = xasprintf (gettext ("\
 For bug reporting instructions, please see:\n\
-%s.\n"), REPORT_BUGS_TO) < 0)
-	return NULL;
-      if (asprintf (&cp, gettext ("\
+%s.\n"), REPORT_BUGS_TO);
+      cp = xasprintf (gettext ("\
 System's directory for character maps : %s\n\
 		       repertoire maps: %s\n\
 		       locale path    : %s\n\
 %s"),
-		    CHARMAP_PATH, REPERTOIREMAP_PATH, LOCALE_PATH, tp) < 0)
-	{
-	  free (tp);
-	  return NULL;
-	}
+		    CHARMAP_PATH, REPERTOIREMAP_PATH, LOCALE_PATH, tp);
+      free (tp);
       return cp;
     default:
       break;
@@ -477,15 +474,13 @@ error_print (void)
 }
 
 
-/* The parameter to localedef describes the output path.  If it does
-   contain a '/' character it is a relative path.  Otherwise it names the
-   locale this definition is for.  */
-static const char *
+/* The parameter to localedef describes the output path.  If it does contain a
+   '/' character it is a relative path.  Otherwise it names the locale this
+   definition is for.   The returned path must be freed by the caller. */
+static char *
 construct_output_path (char *path)
 {
-  const char *normal = NULL;
   char *result;
-  char *endp;
 
   if (strchr (path, '/') == NULL)
     {
@@ -493,50 +488,44 @@ construct_output_path (char *path)
 	 contains a reference to the codeset.  This should be
 	 normalized.  */
       char *startp;
+      char *endp = NULL;
+      char *normal = NULL;
 
       startp = path;
-      /* We must be prepared for finding a CEN name or a location of
-	 the introducing `.' where it is not possible anymore.  */
+      /* Either we have a '@' which starts a CEN name or '.' which starts the
+	 codeset specification.  The CEN name starts with '@' and may also have
+	 a codeset specification, but we do not normalize the string after '@'.
+	 If we only find the codeset specification then we normalize only the codeset
+	 specification (but not anything after a subsequent '@').  */
       while (*startp != '\0' && *startp != '@' && *startp != '.')
 	++startp;
       if (*startp == '.')
 	{
 	  /* We found a codeset specification.  Now find the end.  */
 	  endp = ++startp;
+
+	  /* Stop at the first '@', and don't normalize anything past that.  */
 	  while (*endp != '\0' && *endp != '@')
 	    ++endp;
 
 	  if (endp > startp)
 	    normal = normalize_codeset (startp, endp - startp);
 	}
-      else
-	/* This is to keep gcc quiet.  */
-	endp = NULL;
 
-      /* We put an additional '\0' at the end of the string because at
-	 the end of the function we need another byte for the trailing
-	 '/'.  */
-      ssize_t n;
       if (normal == NULL)
-	n = asprintf (&result, "%s%s/%s%c", output_prefix ?: "",
-		      COMPLOCALEDIR, path, '\0');
+	result = xasprintf ("%s%s/%s/", output_prefix ?: "",
+			    COMPLOCALEDIR, path);
       else
-	n = asprintf (&result, "%s%s/%.*s%s%s%c",
-		      output_prefix ?: "", COMPLOCALEDIR,
-		      (int) (startp - path), path, normal, endp, '\0');
-
-      if (n < 0)
-	return NULL;
-
-      endp = result + n - 1;
+	result = xasprintf ("%s%s/%.*s%s%s/",
+			    output_prefix ?: "", COMPLOCALEDIR,
+			    (int) (startp - path), path, normal, endp ?: "");
+      /* Free the allocated normalized codeset name.  */
+      free (normal);
     }
   else
     {
-      /* This is a user path.  Please note the additional byte in the
-	 memory allocation.  */
-      size_t len = strlen (path) + 1;
-      result = xmalloc (len + 1);
-      endp = mempcpy (result, path, len) - 1;
+      /* This is a user path.  */
+      result = xasprintf ("%s/", path);
 
       /* If the user specified an output path we cannot add the output
 	 to the archive.  */
@@ -546,25 +535,41 @@ construct_output_path (char *path)
   errno = 0;
 
   if (no_archive && euidaccess (result, W_OK) == -1)
-    /* Perhaps the directory does not exist now.  Try to create it.  */
-    if (errno == ENOENT)
-      {
-	errno = 0;
-	if (mkdir (result, 0777) < 0)
-	  return NULL;
-      }
-
-  *endp++ = '/';
-  *endp = '\0';
+    {
+      /* Perhaps the directory does not exist now.  Try to create it.  */
+      if (errno == ENOENT)
+	{
+	  errno = 0;
+	  if (mkdir (result, 0777) < 0)
+	    {
+	      record_verbose (stderr,
+			      _("cannot create output path \'%s\': %s"),
+			      result, strerror (errno));
+	      free (result);
+	      return NULL;
+	    }
+	}
+      else
+	record_verbose (stderr,
+			_("no write permission to output path \'%s\': %s"),
+			result, strerror (errno));
+    }
 
   return result;
 }
 
 
-/* Normalize codeset name.  There is no standard for the codeset
-   names.  Normalization allows the user to use any of the common
-   names.  */
-static const char *
+/* Normalize codeset name.  There is no standard for the codeset names.
+   Normalization allows the user to use any of the common names e.g. UTF-8,
+   utf-8, utf8, UTF8 etc.
+
+   We normalize using the following rules:
+   - Remove all non-alpha-numeric characters
+   - Lowercase all characters.
+   - If there are only digits assume it's an ISO standard and prefix with 'iso'
+
+   We return the normalized string which needs to be freed by free.  */
+static char *
 normalize_codeset (const char *codeset, size_t name_len)
 {
   int len = 0;
@@ -573,6 +578,7 @@ normalize_codeset (const char *codeset, size_t name_len)
   char *wp;
   size_t cnt;
 
+  /* Compute the length of only the alpha-numeric characters.  */
   for (cnt = 0; cnt < name_len; ++cnt)
     if (isalnum (codeset[cnt]))
       {
@@ -582,25 +588,24 @@ normalize_codeset (const char *codeset, size_t name_len)
 	  only_digit = 0;
       }
 
-  retval = (char *) malloc ((only_digit ? 3 : 0) + len + 1);
+  /* If there were only digits we assume it's an ISO standard and we will
+     prefix with 'iso' so include space for that.  We fill in the required
+     space from codeset up to the converted length.  */
+  wp = retval = xasprintf ("%s%.*s", only_digit ? "iso" : "", len, codeset);
 
-  if (retval != NULL)
-    {
-      if (only_digit)
-	wp = stpcpy (retval, "iso");
-      else
-	wp = retval;
-
-      for (cnt = 0; cnt < name_len; ++cnt)
-	if (isalpha (codeset[cnt]))
-	  *wp++ = tolower (codeset[cnt]);
-	else if (isdigit (codeset[cnt]))
-	  *wp++ = codeset[cnt];
+  /* Skip "iso".  */
+  if (only_digit)
+    wp += 3;
 
-      *wp = '\0';
-    }
+  /* Lowercase all characters. */
+  for (cnt = 0; cnt < name_len; ++cnt)
+    if (isalpha (codeset[cnt]))
+      *wp++ = tolower (codeset[cnt]);
+    else if (isdigit (codeset[cnt]))
+      *wp++ = codeset[cnt];
 
-  return (const char *) retval;
+  /* Return allocated and converted name for caller to free.  */
+  return retval;
 }
 
 
diff --git a/locale/programs/localedef.h b/locale/programs/localedef.h
index 62ad717..c98acf1 100644
--- a/locale/programs/localedef.h
+++ b/locale/programs/localedef.h
@@ -123,6 +123,7 @@ extern bool hard_links;
 
 /* Prototypes for a few program-wide used functions.  */
 #include <programs/xmalloc.h>
+#include <programs/xasprintf.h>
 
 
 /* Mark given locale as to be read.  */
diff --git a/locale/programs/xasprintf.c b/locale/programs/xasprintf.c
new file mode 100644
index 0000000..efc91a9
--- /dev/null
+++ b/locale/programs/xasprintf.c
@@ -0,0 +1,34 @@
+/* asprintf with out of memory checking
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published
+   by the Free Software Foundation; version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <libintl.h>
+#include <error.h>
+
+char *
+xasprintf (const char *format, ...)
+{
+  va_list ap;
+  va_start (ap, format);
+  char *result;
+  if (vasprintf (&result, format, ap) < 0)
+    error (EXIT_FAILURE, 0, _("memory exhausted"));
+  va_end (ap);
+  return result;
+}
diff --git a/locale/tst-localedef-path-norm.c b/locale/tst-localedef-path-norm.c
new file mode 100644
index 0000000..2ef1d26
--- /dev/null
+++ b/locale/tst-localedef-path-norm.c
@@ -0,0 +1,242 @@
+/* Test for localedef path name handling and normalization.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* The test runs localedef with various named paths to test for expected
+   behaviours dealing with codeset name normalization.  That is to say that use
+   of UTF-8, and it's variations, are normalized to utf8.  Likewise that values
+   after the @ are not normalized and left as-is.  The test needs to run
+   localedef with known input values and then check that the generated path
+   matches the expected value after normalization.  */
+
+/* Note: In some cases adding -v (verbose) to localedef changes the exit
+   status to a non-zero value because some warnings are only enabled in verbose
+   mode.  This should probably be changed so warnings are either present or not
+   present, regardless of verbosity.  POSIX requires that any warnings cause the
+   exit status to be non-zero.  */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <support/capture_subprocess.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xunistd.h>
+
+/* Full path to localedef.  */
+char *prog;
+
+/* Execute localedef in a subprocess.  */
+static void
+execv_wrapper (void *args)
+{
+  char **argv = args;
+
+  execv (prog, argv);
+  FAIL_EXIT1 ("execv: %m");
+}
+
+struct test_closure
+{
+  /* Arguments for running localedef.  */
+  const char *const argv[16];
+  /* Expected directory name for compiled locale.  */
+  const char *exp;
+  /* Expected path to compiled locale.  */
+  const char *complocaledir;
+};
+
+/* Run localedef with DATA.ARGV arguments (NULL terminated), and expect path to
+   the compiled locale is "DATA.COMPLOCALEDIR/DATA.EXP".  */
+static void
+run_test (struct test_closure data)
+{
+  const char * const *args = data.argv;
+  const char *exp = data.exp;
+  const char *complocaledir = data.complocaledir;
+  struct stat64 fs;
+
+  /* Expected output path.  */
+  const char *path = xasprintf ("%s/%s", complocaledir, exp);
+
+  /* Run test.  */
+  struct support_capture_subprocess result;
+  result = support_capture_subprocess (execv_wrapper, (void *)args);
+  support_capture_subprocess_check (&result, "execv", 0, sc_allow_none);
+  support_capture_subprocess_free (&result);
+
+  /* Verify path is present and is a directory.  */
+  xstat (path, &fs);
+  TEST_VERIFY_EXIT (S_ISDIR (fs.st_mode));
+  printf ("info: Directory '%s' exists.\n", path);
+}
+
+static int
+do_test (void)
+{
+  /* We are running as root inside the container.  */
+  prog = xasprintf ("%s/localedef", support_bindir_prefix);
+
+  /* Create the needed directories:
+     - We need the default compiled locale dir for default output.
+     - We need an arbitrary absolute path for localedef output.
+
+     Note: Writing to a non-default absolute path disables any kind
+     of path normalization since we expect the user wants the path
+     exactly as they specified it.  */
+  xmkdirp (support_complocaledir_prefix, 0777);
+  xmkdirp ("/output", 0777);
+
+  /* It takes ~10 seconds to serially execute 9 localedef test.  We
+     could run the compilations in parallel if we want to reduce test
+     time.  We don't want to split this out into distinct tests because
+     it would require multiple chroots.  Batching the same localedef
+     tests saves disk space during testing.  */
+
+  /* Test 1: Expected normalization.
+     Run localedef and expect output in /usr/lib/locale/en_US1.utf8,
+     with normalization changing UTF-8 to utf8.  */
+  run_test ((struct test_closure)
+	    {
+	      .argv = { prog,
+			"--no-archive",
+			"-i", "en_US",
+			"-f", "UTF-8",
+			"en_US1.UTF-8", NULL },
+	      .exp = "en_US1.utf8",
+	      .complocaledir = support_complocaledir_prefix
+	    });
+
+  /* Test 2: No normalization past '@'.
+     Run localedef and expect output in /usr/lib/locale/en_US2.utf8@tEsT,
+     with normalization changing UTF-8@tEsT to utf8@tEsT (everything after
+     @ is untouched).  */
+  run_test ((struct test_closure)
+	    {
+	      .argv = { prog,
+			"--no-archive",
+			"-i", "en_US",
+			"-f", "UTF-8",
+			"en_US2.UTF-8@tEsT", NULL },
+	      .exp = "en_US2.utf8@tEsT",
+	      .complocaledir = support_complocaledir_prefix
+	    });
+
+  /* Test 3: No normalization past '@' despite period.
+     Run localedef and expect output in /usr/lib/locale/en_US3@tEsT.UTF-8,
+     with normalization changing nothing (everything after @ is untouched)
+     despite there being a period near the end.  */
+  run_test ((struct test_closure)
+	    {
+	      .argv = { prog,
+			"--no-archive",
+			"-i", "en_US",
+			"-f", "UTF-8",
+			"en_US3@tEsT.UTF-8", NULL },
+	      .exp = "en_US3@tEsT.UTF-8",
+	      .complocaledir = support_complocaledir_prefix
+	    });
+
+  /* Test 4: Normalize numeric codeset by adding 'iso' prefix.
+     Run localedef and expect output in /usr/lib/locale/en_US4.88591,
+     with normalization changing 88591 to iso88591.  */
+  run_test ((struct test_closure)
+	    {
+	      .argv = { prog,
+			"--no-archive",
+			"-i", "en_US",
+			"-f", "UTF-8",
+			"en_US4.88591", NULL },
+	      .exp = "en_US4.iso88591",
+	      .complocaledir = support_complocaledir_prefix
+	    });
+
+  /* Test 5: Don't add 'iso' prefix if first char is alpha.
+     Run localedef and expect output in /usr/lib/locale/en_US5.a88591,
+     with normalization changing nothing.  */
+  run_test ((struct test_closure)
+	    {
+	      .argv = { prog,
+			"--no-archive",
+			"-i", "en_US",
+			"-f", "UTF-8",
+			"en_US5.a88591", NULL },
+	      .exp = "en_US5.a88591",
+	      .complocaledir = support_complocaledir_prefix
+	    });
+
+  /* Test 6: Don't add 'iso' prefix if last char is alpha.
+     Run localedef and expect output in /usr/lib/locale/en_US6.88591a,
+     with normalization changing nothing.  */
+  run_test ((struct test_closure)
+	    {
+	      .argv = { prog,
+			"--no-archive",
+			"-i", "en_US",
+			"-f", "UTF-8",
+			"en_US6.88591a", NULL },
+	      .exp = "en_US6.88591a",
+	      .complocaledir = support_complocaledir_prefix
+	    });
+
+  /* Test 7: Don't normalize anything with an absolute path.
+     Run localedef and expect output in /output/en_US7.UTF-8,
+     with normalization changing nothing.  */
+  run_test ((struct test_closure)
+	    {
+	      .argv = { prog,
+			"--no-archive",
+			"-i", "en_US",
+			"-f", "UTF-8",
+			"/output/en_US7.UTF-8", NULL },
+	      .exp = "en_US7.UTF-8",
+	      .complocaledir = "/output"
+	    });
+
+  /* Test 8: Don't normalize anything with an absolute path.
+     Run localedef and expect output in /output/en_US8.UTF-8@tEsT,
+     with normalization changing nothing.  */
+  run_test ((struct test_closure)
+	    {
+	      .argv = { prog,
+			"--no-archive",
+			"-i", "en_US",
+			"-f", "UTF-8",
+			"/output/en_US8.UTF-8@tEsT", NULL },
+	      .exp = "en_US8.UTF-8@tEsT",
+	      .complocaledir = "/output"
+	    });
+
+  /* Test 9: Don't normalize anything with an absolute path.
+     Run localedef and expect output in /output/en_US9@tEsT.UTF-8,
+     with normalization changing nothing.  */
+  run_test ((struct test_closure)
+	    {
+	      .argv = { prog,
+			"--no-archive",
+			"-i", "en_US",
+			"-f", "UTF-8",
+			"/output/en_US9@tEsT.UTF-8", NULL },
+	      .exp = "en_US9@tEsT.UTF-8",
+	      .complocaledir = "/output"
+	    });
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/locale/tst-localedef-path-norm.root/postclean.req b/locale/tst-localedef-path-norm.root/postclean.req
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/locale/tst-localedef-path-norm.root/postclean.req
diff --git a/locale/tst-localedef-path-norm.root/tst-localedef-path-norm.script b/locale/tst-localedef-path-norm.root/tst-localedef-path-norm.script
new file mode 100644
index 0000000..b0f0162
--- /dev/null
+++ b/locale/tst-localedef-path-norm.root/tst-localedef-path-norm.script
@@ -0,0 +1,2 @@
+# Must run localedef as root to write into default paths.
+su
diff --git a/support/Makefile b/support/Makefile
index 6e38b87..9364f3b 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -189,7 +189,8 @@ CFLAGS-support_paths.c = \
 		-DLIBDIR_PATH=\"$(libdir)\" \
 		-DBINDIR_PATH=\"$(bindir)\" \
 		-DSBINDIR_PATH=\"$(sbindir)\" \
-		-DROOTSBINDIR_PATH=\"$(rootsbindir)\"
+		-DROOTSBINDIR_PATH=\"$(rootsbindir)\" \
+		-DCOMPLOCALEDIR_PATH=\"$(complocaledir)\"
 
 ifeq (,$(CXX))
 LINKS_DSO_PROGRAM = links-dso-program-c
diff --git a/support/support.h b/support/support.h
index 77d68c2..8e1a6a1 100644
--- a/support/support.h
+++ b/support/support.h
@@ -112,6 +112,8 @@ extern const char support_bindir_prefix[];
 extern const char support_sbindir_prefix[];
 /* Corresponds to the install's sbin/ directory (without prefix).  */
 extern const char support_install_rootsbindir[];
+/* Corresponds to the install's compiled locale directory.  */
+extern const char support_complocaledir_prefix[];
 
 extern ssize_t support_copy_file_range (int, off64_t *, int, off64_t *,
 					size_t, unsigned int);
diff --git a/support/support_paths.c b/support/support_paths.c
index 9f10879..edc6511 100644
--- a/support/support_paths.c
+++ b/support/support_paths.c
@@ -78,3 +78,10 @@ const char support_install_rootsbindir[] = ROOTSBINDIR_PATH;
 #else
 # error please -DROOTSBINDIR_PATH=something in the Makefile
 #endif
+
+#ifdef COMPLOCALEDIR_PATH
+/* Corresponds to the install's compiled locale directory.  */
+const char support_complocaledir_prefix[] = COMPLOCALEDIR_PATH;
+#else
+# error please -DCOMPLOCALEDIR_PATH=something in the Makefile
+#endif