build: rely on gnulib's progname module

* bootstrap.conf (gnulib_modules): Add progname.
* cfg.mk (local-checks-to-skip): Add sc_program_name.
* src/cmp.c: Include progname.h.
(program_name): Remove declaration.
(main): Call set_program_name.
* src/diff.c (main): Likewise.
* src/diff3.c (main): Likewise.
* src/sdiff.c (main): Likewise.
* src/diff.h (program_name): Remove extern declaration.

bootstrap.conf

@@ -47,6 +47,7 @@ inttypes
 maintainer-makefile
 mbrtowc
 mkstemp
+progname
 regex
 sh-quote
 stat-macros

cfg.mk

@@ -34,8 +34,7 @@ gpg_key_ID = B9AB9A16
 local-checks-to-skip =		\
   sc_error_message_period	\
   sc_error_message_uppercase	\
-  sc_m4_quote_check		\
-  sc_program_name
+  sc_m4_quote_check
 
 # Tools used to bootstrap this package, used for "announcement".
 bootstrap-tools = autoconf,automake,gnulib

src/cmp.c

@@ -29,6 +29,7 @@
 #include <getopt.h>
 #include <hard-locale.h>
 #include <inttostr.h>
+#include <progname.h>
 #include <unlocked-io.h>
 #include <version-etc.h>
 #include <xalloc.h>
@@ -46,9 +47,6 @@ static size_t block_compare (word const *, word const *);
 static size_t block_compare_and_count (word const *, word const *, off_t *);
 static void sprintc (char *, unsigned char);
 
-/* Name under which this program was invoked.  */
-char *program_name;
-
 /* Filenames of the compared files.  */
 static char const *file[2];
 
@@ -192,7 +190,7 @@ main (int argc, char **argv)
 
   exit_failure = EXIT_TROUBLE;
   initialize_main (&argc, &argv);
-  program_name = argv[0];
+  set_program_name (argv[0]);
   setlocale (LC_ALL, "");
   bindtextdomain (PACKAGE, LOCALEDIR);
   textdomain (PACKAGE);

src/diff.c

@@ -31,6 +31,7 @@
 #include <getopt.h>
 #include <hard-locale.h>
 #include <prepargs.h>
+#include <progname.h>
 #include <sh-quote.h>
 #include <stat-time.h>
 #include <timespec.h>
@@ -202,11 +203,6 @@ static struct option const longopts[] =
   {0, 0, 0, 0}
 };
 
-/* Program name.  */
-char *program_name;
-
-
-
 /* Return a string containing the command options with which diff was invoked.
    Spaces appear between what were separate ARGV-elements.
    There is a space at the beginning but none at the end.
@@ -266,7 +262,7 @@ main (int argc, char **argv)
   /* Do our initializations.  */
   exit_failure = 2;
   initialize_main (&argc, &argv);
-  program_name = argv[0];
+  set_program_name (argv[0]);
   setlocale (LC_ALL, "");
   bindtextdomain (PACKAGE, LOCALEDIR);
   textdomain (PACKAGE);

src/diff.h

@@ -199,9 +199,6 @@ XTERN struct exclude *excluded;
    slower) but will find a guaranteed minimal set of changes.  */
 XTERN bool minimal;
 
-/* Name of program the user invoked (for error messages).  */
-XTERN char *program_name;
-
 /* The strftime format to use for time strings.  */
 XTERN char const *time_format;
 

src/diff3.c

@@ -29,6 +29,7 @@
 #include <file-type.h>
 #include <getopt.h>
 #include <inttostr.h>
+#include <progname.h>
 #include <sh-quote.h>
 #include <version-etc.h>
 #include <xalloc.h>
@@ -158,8 +159,6 @@ static bool finalwrite;
 /* If nonzero, output a merged file.  */
 static bool merge;
 
-char *program_name;
-
 static char *read_diff (char const *, char const *, char **);
 static char *scan_diff_line (char *, char **, size_t *, char *, char);
 static enum diff_type process_diff_control (char **, struct diff_block *);
@@ -226,7 +225,7 @@ main (int argc, char **argv)
 
   exit_failure = 2;
   initialize_main (&argc, &argv);
-  program_name = argv[0];
+  set_program_name (argv[0]);
   setlocale (LC_ALL, "");
   bindtextdomain (PACKAGE, LOCALEDIR);
   textdomain (PACKAGE);

src/sdiff.c

@@ -30,6 +30,7 @@
 #include <exitfail.h>
 #include <file-type.h>
 #include <getopt.h>
+#include <progname.h>
 #include <sh-quote.h>
 #include <version-etc.h>
 #include <xalloc.h>
@@ -37,8 +38,6 @@
 /* Size of chunks read from files which must be parsed into lines.  */
 #define SDIFF_BUFSIZE ((size_t) 65536)
 
-char *program_name;
-
 static char const *editor_program = DEFAULT_EDITOR_PROGRAM;
 static char const **diffargv;
 
@@ -459,7 +458,7 @@ main (int argc, char *argv[])
 
   exit_failure = EXIT_TROUBLE;
   initialize_main (&argc, &argv);
-  program_name = argv[0];
+  set_program_name (argv[0]);
   setlocale (LC_ALL, "");
   bindtextdomain (PACKAGE, LOCALEDIR);
   textdomain (PACKAGE);