Move Texinfo related autoconf code to a new separate texinfo.m4 file.

2 files changed, 59 insertions, 38 deletions

diff --git a/configure.ac b/configure.ac
index ef64ef5918d..7e85646bd4c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2107,44 +2107,7 @@ if test $opsys = darwin; then
   AC_PATH_PROG([HAVE_MACPORTS], [port])
 fi
 
-## Require makeinfo >= 4.13 (last of the 4.x series) to build the manuals.
-: ${MAKEINFO:=makeinfo}
-case `($MAKEINFO --version) 2>/dev/null` in
-  *' (GNU texinfo) '4.1[[3-9]]* | \
-  *' (GNU texinfo) '[[5-9]]* | \
-  *' (GNU texinfo) '[[1-9][0-9]]* ) ;;
-  *) MAKEINFO=no;;
-esac
-
-## Makeinfo is unusual.  For a released Emacs, the manuals are
-## pre-built, and not deleted by the normal clean rules.  makeinfo is
-## therefore in the category of "special tools" not normally required, which
-## configure does not have to check for (eg autoconf itself).
-## In a repository checkout on the other hand, the manuals are not included.
-## So makeinfo is a requirement to build from the repository, and configure
-## should test for it as it does for any other build requirement.
-## We use the presence of $srcdir/info/emacs to distinguish a release,
-## with pre-built manuals, from a repository checkout.
-if test "$MAKEINFO" = "no"; then
-  MAKEINFO=makeinfo
-  if test ! -e "$srcdir/info/emacs" && test ! -e "$srcdir/info/emacs.info"; then
-    AC_MSG_ERROR( [You do not seem to have makeinfo >= 4.13, and your
-source tree does not seem to have pre-built manuals in the 'info' directory.
-Please install a suitable version of makeinfo.] )
-  else
-    AC_MSG_WARN( [You do not seem to have makeinfo >= 4.13.
-You will not be able to rebuild the manuals if you delete them or change
-their sources.] )
-  fi
-fi
-AC_SUBST([MAKEINFO])
-
-if test $opsys = mingw32; then
-   DOCMISC_W32=efaq-w32
-else
-   DOCMISC_W32=
-fi
-AC_SUBST([DOCMISC_W32])
+gl_TEXINFO
 
 dnl Add our options to ac_link now, after it is set up.
 
diff --git a/m4/texinfo.m4 b/m4/texinfo.m4
new file mode 100644
index 00000000000..66e8abd8602
--- /dev/null
+++ b/m4/texinfo.m4
@@ -0,0 +1,58 @@
+# texinfo.m4
+dnl Copyright (C) 2026 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+dnl This file is offered as-is, without any warranty.
+dnl
+dnl
+AC_DEFUN([gl_TEXINFO],[dnl
+AC_REQUIRE([gl_SET_MAKEINFO])
+AC_REQUIRE([gl_SET_DOCMISC_W32])
+])
+dnl
+dnl gl_FIND_MAKEINFO
+AC_DEFUN([gl_SET_MAKEINFO],[dnl
+[## Require makeinfo >= 4.13 (last of the 4.x series) to build the manuals.
+: ${MAKEINFO:=makeinfo}
+case `($MAKEINFO --version) 2>/dev/null` in
+  *' (GNU texinfo) '4.1[[3-9]]* | \
+  *' (GNU texinfo) '[[5-9]]* | \
+  *' (GNU texinfo) '[[1-9][0-9]]* ) ;;
+  *) MAKEINFO=no;;
+esac
+
+## Makeinfo is unusual.  For a released Emacs, the manuals are
+## pre-built, and not deleted by the normal clean rules.  makeinfo is
+## therefore in the category of "special tools" not normally required, which
+## configure does not have to check for (eg autoconf itself).
+## In a repository checkout on the other hand, the manuals are not included.
+## So makeinfo is a requirement to build from the repository, and configure
+## should test for it as it does for any other build requirement.
+## We use the presence of $srcdir/info/emacs to distinguish a release,
+## with pre-built manuals, from a repository checkout.
+if test "$MAKEINFO" = "no"; then
+  MAKEINFO=makeinfo
+  if test ! -e "$srcdir/info/emacs" && test ! -e "$srcdir/info/emacs.info"; then
+    ]AC_MSG_ERROR( [You do not seem to have makeinfo >= 4.13, and your
+source tree does not seem to have pre-built manuals in the 'info' directory.
+Please install a suitable version of makeinfo.] )[
+  else
+    ]AC_MSG_WARN( [You do not seem to have makeinfo >= 4.13.
+You will not be able to rebuild the manuals if you delete them or change
+their sources.] )[
+  fi
+fi
+]AC_SUBST([MAKEINFO])
+])
+dnl
+dnl gl_SET_DOCMISC_W32
+AC_DEFUN([gl_SET_DOCMISC_W32],[dnl
+[if test $opsys = mingw32; then
+   DOCMISC_W32=efaq-w32
+else
+   DOCMISC_W32=
+fi
+]AC_SUBST([DOCMISC_W32])
+])
+dnl