# HG changeset patch
# User Bruno Haible <bruno@clisp.org>
# Date 1516695193 -3600
# Node ID c2e83c6de345b6a4121c86cb56ea1963427fdbe9
# Parent  3c40257da226da6b78866a5d90c8832eb9345fca
doc: Mention another prerequisite for using Gnulib.

Reported at <https://stackoverflow.com/questions/48378214/>.

* doc/gnulib-tool.texi (Initial import): Mention requirement to use
AC_CONFIG_HEADERS.

diff -r 3c40257da226 -r c2e83c6de345 ChangeLog
--- a/ChangeLog	Mon Jan 22 22:14:55 2018 +0100
+++ b/ChangeLog	Tue Jan 23 09:13:13 2018 +0100
@@ -1,3 +1,10 @@
+2018-01-23  Bruno Haible  <bruno@clisp.org>
+
+	doc: Mention another prerequisite for using Gnulib.
+	Reported at <https://stackoverflow.com/questions/48378214/>.
+	* doc/gnulib-tool.texi (Initial import): Mention requirement to use
+	AC_CONFIG_HEADERS.
+
 2018-01-22  Mathieu Lirzin  <mthl@gnu.org>
 
 	build: GuixSD doesn't have /bin/bash
diff -r 3c40257da226 -r c2e83c6de345 doc/gnulib-tool.texi
--- a/doc/gnulib-tool.texi	Mon Jan 22 22:14:55 2018 +0100
+++ b/doc/gnulib-tool.texi	Tue Jan 23 09:13:13 2018 +0100
@@ -87,6 +87,14 @@
 Gnulib assumes that your project uses Autoconf.  When using Gnulib, you
 will need to have Autoconf among your build tools.
 
+Gnulib also assumes that your project's @file{configure.ac} contains the
+line
+@smallexample
+AC_CONFIG_HEADERS([config.h])
+@end smallexample
+The @file{config.h} file gets generated with platform dependent C macro
+definitions, and the source files include it (see @ref{Source changes}).
+
 Unless you use @command{gnulib-tool}'s @option{--gnu-make} option,
 Gnulib also assumes that your project uses Automake at least in a
 subdirectory of your project.  While the use of Automake in your