From 8cb0d6d7fa9aaac316c29a64c541336b51b6f93d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Wed, 12 Mar 2014 14:35:07 +0100
Subject: [PATCH] build: Don't include <config.h> in native programs when
 cross-compiling.

* libguile/Makefile.am (gen-scmconfig.$(OBJEXT)): When cross-compiling,
  pass -DCROSS_COMPILING=1.
  (c-tokenize.$(OBJEXT)): Likewise.
* libguile/c-tokenize.lex (%top): Include <config.h> only when
  CROSS_COMPILING is undefined.
* libguile/gen-scmconfig.c: Likewise.
---
 libguile/Makefile.am     | 24 +++++++++++++-----------
 libguile/c-tokenize.lex  |  9 +++++++--
 libguile/gen-scmconfig.c |  8 +++++---
 3 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/libguile/Makefile.am b/libguile/Makefile.am
index 6a631d89f..9be6d0fda 100644
--- a/libguile/Makefile.am
+++ b/libguile/Makefile.am
@@ -60,12 +60,13 @@ gen_scmconfig_SOURCES = gen-scmconfig.c
 ## the generated config.h and gen-scmconfig.h.  Nothing else from Guile
 ## is included by this code generator.
 gen-scmconfig.$(OBJEXT): gen-scmconfig.c
-	$(AM_V_GEN) \
-	if [ "$(cross_compiling)" = "yes" ]; then \
-		$(CC_FOR_BUILD) $(DEFS) $(DEFAULT_INCLUDES) -I$(top_builddir) \
-		   -c -o $@ $<; \
-	else \
-		$(COMPILE) -c -o $@ $<; \
+	$(AM_V_GEN)						\
+	if [ "$(cross_compiling)" = "yes" ]; then		\
+		$(CC_FOR_BUILD) -DCROSS_COMPILING=1 $(DEFS)	\
+		   $(DEFAULT_INCLUDES) -I$(top_builddir)	\
+		   -c -o "$@" "$<";				\
+	else							\
+		$(COMPILE) -c -o "$@" "$<";			\
 	fi
 
 ## Override default rule; this should run on BUILD host.
@@ -92,11 +93,12 @@ guile_filter_doc_snarfage_SOURCES = c-tokenize.c
 ## Override default rule; this should be compiled for BUILD host.
 ## For some reason, OBJEXT does not include the dot
 c-tokenize.$(OBJEXT): c-tokenize.c
-	$(AM_V_GEN) \
-	if [ "$(cross_compiling)" = "yes" ]; then \
-		$(CC_FOR_BUILD) -I$(top_builddir) -c -o $@ $<; \
-	else \
-		$(COMPILE) -c -o $@ $<; \
+	$(AM_V_GEN)							\
+	if [ "$(cross_compiling)" = "yes" ]; then			\
+		$(CC_FOR_BUILD) -DCROSS_COMPILING=1 -I$(top_builddir)	\
+	           -c -o "$@" "$<";					\
+	else								\
+		$(COMPILE) -c -o "$@" "$<";				\
 	fi
 
 ## Override default rule; this should run on BUILD host.
diff --git a/libguile/c-tokenize.lex b/libguile/c-tokenize.lex
index a64b61da4..03fe9898c 100644
--- a/libguile/c-tokenize.lex
+++ b/libguile/c-tokenize.lex
@@ -1,7 +1,12 @@
 %top{
 /* Include <config.h> before anything else because Gnulib headers such
-   as <stdio.h> rely on it.  */
-#include <config.h>
+   as <stdio.h> rely on it.
+
+   However, when cross-compiling, don't include <config.h> because it
+   contains information about the host, not about the build.  */
+#ifndef CROSS_COMPILING
+# include <config.h>
+#endif
 }
 
 %option noyywrap
diff --git a/libguile/gen-scmconfig.c b/libguile/gen-scmconfig.c
index 2f6fa6e6a..3c8be4f8e 100644
--- a/libguile/gen-scmconfig.c
+++ b/libguile/gen-scmconfig.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2003-2013 Free Software Foundation, Inc.
+/* Copyright (C) 2003-2014 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -132,8 +132,10 @@
 
  **********************************************************************/
 
-#ifdef HAVE_CONFIG_H
-#  include <config.h>
+/* Don't include <config.h> when cross-compiling because it contains
+   information about the host, not about the build machine.  */
+#ifndef CROSS_COMPILING
+# include <config.h>
 #endif
 
 #include <libguile/gen-scmconfig.h>