Rely on gnulib for strerror() if necessary.

* bootstrap.conf: Add "strerror" to `gnulib_modules`.

* configure.ac: Drop "sterror" from `AC_REPLACE_FUNCS`; we don't need
  Autoconf's replacement if we've got gnulib's.

* Makefile.am: Drop mention of function/macro in comment.

* src/include/lib.h: Drop C preprocessor conditional logic.

* src/roff/groff/pipeline.c: Drop fallback definition.  Let existing
  "<config.h"> inclusion do the work, and include "<string.h>"
  unconditionally.

ChangeLog

@@ -1,3 +1,16 @@
+2024-11-29  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+	Rely on gnulib for `strerror()` if necessary.
+
+	* bootstrap.conf: Add "strerror" to `gnulib_modules`.
+	* configure.ac: Drop "sterror" from `AC_REPLACE_FUNCS`; we don't
+	need Autoconf's replacement if we've got gnulib's.
+	* Makefile.am: Drop mention of function/macro in comment.
+	* src/include/lib.h: Drop C preprocessor conditional logic.
+	* src/roff/groff/pipeline.c: Drop fallback definition.  Let
+	existing "<config.h"> inclusion do the work, and include
+	"<string.h>" unconditionally.
+
 2024-11-29  G. Branden Robinson <g.branden.robinson@gmail.com>
 
 	[troff]: Align with modern groff conventions.

Makefile.am

@@ -307,7 +307,6 @@ man7dir=$(manroot)/man$(man7ext)
 # HAVE_SETLOCALE		if you have setlocale()
 # HAVE_STRCASECMP		if you have strcasecmp()
 # HAVE_STRNCASECMP		if you have strncasecmp()
-# HAVE_STRERROR		if you have strerror()
 # HAVE_STRSEP			if you have strsep()
 # HAVE_STRTOL			if you have strtol()
 # HAVE_SYMLINK		if you have symlink()

bootstrap.conf

@@ -49,6 +49,7 @@ gnulib_modules="
     stdbool-c99
     stdckdint
     stdint
+    strerror
     sys_wait
 "
 

configure.ac

@@ -130,7 +130,7 @@ AC_FUNC_MMAP
 saved_libs="$LIBS"
 LIBS="$LIBS $LIBC $LIBM"
 AC_REPLACE_FUNCS([fmod getcwd putenv strcasecmp \
-                  strerror strncasecmp strtol])
+                  strncasecmp strtol])
 LIBS="$saved_libs"
 AC_CHECK_FUNCS([gettimeofday isatty kill rename setlocale strdup \
                 strsep])

src/include/lib.h

@@ -25,9 +25,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 
 #ifdef __cplusplus
 extern "C" {
-#endif
-#ifndef HAVE_STRERROR
-  char *strerror(int);
 #endif
   const char *i_to_a(int);
   const char *ui_to_a(unsigned int);

src/roff/groff/pipeline.c

@@ -25,15 +25,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 #include <signal.h>
 #include <errno.h>
 #include <sys/types.h>
+#include <string.h> // strerror(), strsignal()
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
 
-#ifdef HAVE_STRERROR
-#include <string.h>
-#else
-extern char *strerror();
-#endif
 
 #ifdef _POSIX_VERSION