From bd5bd5df26c6a82db479a39022b218fd45765be1 Mon Sep 17 00:00:00 2001
From: midipix <writeonce@midipix.org>
Date: Mon, 21 Sep 2015 23:30:03 -0400
Subject: build system: add support for non-portable host headers.

---
 Makefile.in          |  9 ++++--
 config.project       |  2 +-
 sysinfo/host/host.sh | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+), 3 deletions(-)
 create mode 100755 sysinfo/host/host.sh

diff --git a/Makefile.in b/Makefile.in
index 26365b4..1a71ee7 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -71,10 +71,10 @@ include $(PROJECT_DIR)/project/overrides.mk
 
 $(APP_SRCS:%.c=%.o): CFLAGS_STATIC = $(CFLAGS_APP)
 
-src/%.lo: 	$(PROJECT_DIR)/src/%.c $(ALL_HEADERS)
+src/%.lo: 	$(PROJECT_DIR)/src/%.c $(ALL_HEADERS) host.tag
 		$(CC) -c -o $@ $< $(CFLAGS_SHARED)
 
-src/%.o: 	$(PROJECT_DIR)/src/%.c $(ALL_HEADERS)
+src/%.o: 	$(PROJECT_DIR)/src/%.c $(ALL_HEADERS) host.tag
 		$(CC) -c -o $@ $< $(CFLAGS_STATIC)
 
 $(LIB_DIR)/%$(OS_LIB_SUFFIX):
@@ -165,12 +165,17 @@ dirs.tag:
 		mkdir -p $(LIB_DIR)
 		touch dirs.tag
 
+host.tag:	Makefile
+		$(SHELL) $(PROJECT_DIR)/sysinfo/host/host.sh --compiler="$(CC)" --cflags="$(CFLAGS)"
+		touch host.tag
+
 distclean:	clean
 		rm -f Makefile
 
 clean:
 		rm -f tree.tag
 		rm -f dirs.tag
+		rm -f host.tag
 		rm -f $(SHARED_OBJS)
 		rm -f $(STATIC_OBJS)
 		rm -f $(APP_OBJS)
diff --git a/config.project b/config.project
index 133ed4f..8d3fd41 100644
--- a/config.project
+++ b/config.project
@@ -27,7 +27,7 @@ mb_default_shell=sh
 
 # switches
 mb_default_cflags_debug=
-mb_default_cflags_common="-I\$(PROJECT_DIR)/src/internal -I\$(PROJECT_DIR)/include"
+mb_default_cflags_common="-I\$(PROJECT_DIR)/src/internal -I\$(PROJECT_DIR)/include -Ibuild"
 mb_default_cflags_cmdline=
 mb_default_cflags_config=
 mb_default_cflags_sysroot=
diff --git a/sysinfo/host/host.sh b/sysinfo/host/host.sh
new file mode 100755
index 0000000..50186e7
--- /dev/null
+++ b/sysinfo/host/host.sh
@@ -0,0 +1,82 @@
+#!/bin/sh
+
+error_msg()
+{
+	echo $@ >&2
+}
+
+host_test()
+{
+	mb_hdrdir=$(pwd)/build
+	mkdir -p $mb_hdrdir || exit 2
+
+	if [ x"$mb_compiler" = x ]; then
+                echo "config error: compiler not set."
+		exit 2
+	fi
+
+	"$mb_compiler" -dM -E - < /dev/null > /dev/null && return 0
+
+	error_msg "config error: invalid compiler."
+	exit 2
+}
+
+host_endian_h()
+{
+	mb_header='endian.h'
+	rm -f "$mb_hdrdir"/$mb_header
+
+	# portable
+	"$mb_compiler" $mb_cflags \
+		--include=$mb_header -E - < /dev/null > /dev/null 2>/dev/null \
+		&& return 0
+
+	# non-portable
+	mb_hosthdr=
+
+	[ -z $mb_hosthdr ] && "$mb_compiler" $mb_cflags \
+		--include='sys/'$mb_header -E - < /dev/null > /dev/null 2>/dev/null \
+		&& mb_hosthdr='sys/'$mb_header
+
+	[ -z $mb_hosthdr ] && "$mb_compiler" $mb_cflags \
+		--include='machine/'$mb_header -E - < /dev/null > /dev/null 2>/dev/null \
+		&& mb_hosthdr='machine/'$mb_header
+
+	if [ x"$mb_hosthdr" = x ]; then
+		error_msg "config error: could not find an alternate <$mb_header>."
+		exit 2
+	fi
+
+	printf "#include <%s>\\n" $mb_hosthdr > "$mb_hdrdir"/$mb_header || exit 2
+}
+
+
+# one: args
+for arg ; do
+	case "$arg" in
+		--help)	usage
+			;;
+		--compiler=*)
+			mb_compiler=${arg#*=}
+			;;
+		--cflags=*)
+			mb_cflags=${arg#*=}
+			;;
+		*)
+			error_msg ${arg#}: "unsupported config argument."
+			exit 2
+			;;
+	esac
+done
+
+
+# two: test
+host_test
+
+
+# three: headers
+host_endian_h
+
+
+# all done
+exit 0
-- 
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