>From c81611edbcf05201bb017eb08494d4a00ece30b9 Mon Sep 17 00:00:00 2001
From: "A. Gordon" <address@hidden>
Date: Wed, 23 Jul 2014 21:27:48 -0400
Subject: [PATCH] build: generate man-page only when appropriate

* configure.ac: detect compilation under git (vs tarball), and
cross-compilation.
* Makefile.am:
1) re-generate (and clean) man-page only when building from git.
2) if building from git AND cross-compiling, don't add target for
   man-page - there's no way to generate it.

Possible future improvement: If cross-compliing from git, AND user have
'binfmt' configured to run non-native binaries, then the man-page can be
generated.

Reference:
http://lists.gnu.org/archive/html/bug-hello/2014-07/msg00001.html
---
 Makefile.am  | 9 ++++++++-
 configure.ac | 7 +++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Makefile.am b/Makefile.am
index 44957a4..352898b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -43,15 +43,22 @@ hello_LDADD = $(LIBINTL) $(top_builddir)/lib/lib$(PACKAGE).a
 localedir = $(datadir)/locale
 DEFS = -DLOCALEDIR=\"$(localedir)\" @DEFS@
 
+CLEANFILES =
+
+if !GIT_CROSS_COMPILING
 man_MANS = hello.1
 EXTRA_DIST += $(man_MANS)
-CLEANFILES = $(man_MANS)
+endif
 
+if BUILD_FROM_GIT
 hello.1: hello
 	$(HELP2MAN) --include=$(top_srcdir)/man/hello.x $(top_builddir)/hello -o address@hidden
 	chmod a=r address@hidden
 	mv -f address@hidden $@
 
+CLEANFILES += $(man_MANS)
+endif
+
 TESTS = \
 	tests/greeting-1 \
 	tests/greeting-2 \
diff --git a/configure.ac b/configure.ac
index 6b32fb5..2ac1fa2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -43,6 +43,13 @@ dnl Copyright will apply as long as these sources are in use, e.g., are
 dnl being compiled, which is reasonable year to claim the copyright.
 AC_DEFINE([COPYRIGHT_YEAR], [m4_esyscmd([date +%Y])], [year in copyright message])
 
+dnl Are we building from git checked-out sources, or a tarball ?
+dnl This is used in "Makefile.am" to avoid re-generating the manpage
+dnl when building from tarballs.
+AM_CONDITIONAL([BUILD_FROM_GIT], [test -d "$srcdir/.git"])
+AM_CONDITIONAL([GIT_CROSS_COMPILING],
+               [test -d "$srcdir/.git" && test $cross_compiling = yes])
+
 dnl GNU help2man creates man pages from --help output; in many cases, this
 dnl is sufficient, and obviates the need to maintain man pages separately.
 dnl However, this means invoking executables, which we generally cannot do
-- 
1.9.1