[PATCH v5 11/14] autoconf: xen: move standard variables to a generic place

["Luis R. Rodriguez" <mcgrof@do-not-panic.com>]

From: "Luis R. Rodriguez" <mcgrof@suse.com>

This moves all generic variables to the top level makefile,
tons of files use these so just make them general enough. This
also paves the way to let us easily dynamically configure these
with autoconf, for now we leave the same presets as was present
before.

This work was prompted by looking for an autoconf way to do
replacements for the hotplug global file, while at it I realized
that a few other files use the same variables and have in places
around the tree the same constructs for generating their own
files. This replaces all that with a two central files, one for
shell scripts and another for C header files. We should later
optimize this further by only having one target file and
generating the two needed from that.

Building the hypervisor and extras/mini-os without requiring configure
is kept supported by providing a default configuration file with
defaults that will be overwritten only if configure is used.

While at it lets add some documentation on the README and enable us
to expand further details on the wiki [0].

[0] http://wiki.xen.org/wiki/Category:Host_Configuration#System_wide_xen_configuration

Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Tim Deegan <tim@xen.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
---

Please run ./autgen.sh after this patch is applied.

 .gitignore                        |  2 ++
 Config.mk                         | 13 ---------
 README                            | 16 ++++++++++
 config/StdGNU.mk                  | 28 +++++++++---------
 config/Toplevel.mk.in             | 24 +++++++++++++++
 config/defaults.mk                | 21 ++++++++++++++
 config/xen-environment-header.in  | 13 +++++++++
 config/xen-environment-scripts.in | 15 ++++++++++
 configure.ac                      |  9 +++++-
 m4/expand_config.m4               | 61 +++++++++++++++++++++++++++++++++++++++
 stubdom/Makefile                  | 17 ++++++-----
 stubdom/configure.ac              |  3 ++
 tools/configure.ac                |  3 ++
 tools/hotplug/common/Makefile     |  6 ++--
 tools/libxl/Makefile              | 11 ++-----
 tools/python/Makefile             |  6 ++--
 16 files changed, 198 insertions(+), 50 deletions(-)
 create mode 100644 config/defaults.mk
 create mode 100644 config/xen-environment-header.in
 create mode 100644 config/xen-environment-scripts.in
 create mode 100644 m4/expand_config.m4

diff --git a/.gitignore b/.gitignore
index 562c262..fd1b627 100644
--- a/.gitignore
+++ b/.gitignore
@@ -36,6 +36,8 @@ config.log
 config.status
 config.cache
 config/Toplevel.mk
+config/xen-environment-scripts
+config/xen-environment-header
 
 build-*
 dist/*
diff --git a/Config.mk b/Config.mk
index 6a93533..84f79a0 100644
--- a/Config.mk
+++ b/Config.mk
@@ -166,19 +166,6 @@ define move-if-changed
 	if ! cmp -s $(1) $(2); then mv -f $(1) $(2); else rm -f $(1); fi
 endef
 
-buildmakevars2file = $(eval $(call buildmakevars2file-closure,$(1)))
-define buildmakevars2file-closure
-    .PHONY: genpath
-    genpath:
-	rm -f $(1).tmp;                                                     \
-	$(foreach var,                                                      \
-	          SBINDIR BINDIR LIBEXEC LIBDIR SHAREDIR PRIVATE_BINDIR     \
-	          XENFIRMWAREDIR XEN_CONFIG_DIR XEN_SCRIPT_DIR XEN_LOCK_DIR \
-	          XEN_RUN_DIR XEN_PAGING_DIR,                               \
-	          echo "$(var)=\"$($(var))\"" >>$(1).tmp;)        \
-	$(call move-if-changed,$(1).tmp,$(1))
-endef
-
 ifeq ($(debug_symbols),y)
 CFLAGS += -g
 endif
diff --git a/README b/README
index 9bbe734..079e6a9 100644
--- a/README
+++ b/README
@@ -129,6 +129,22 @@ performed with root privileges.]
    versions of those scripts, so that you can copy the dist directory
    to another machine and install from that distribution.
 
+Xen system configuration
+========================
+
+Xen uses a set of variables for system configuration and upon build time,
+because of this these variables are defined on a top level general input
+source and are generated after running ./configure. There are two versions
+of the input files, one for scripts (bash, python) and another for C / header
+files:
+
+  * config/xen-environment-header.in - used to generate config/xen-environment-header 
+  * config/xen-environment-scripts.in - used to generate config/xen-environment-scripts
+
+Further documentation can be found on the wiki:
+
+http://wiki.xen.org/wiki/Category:Host_Configuration#System_wide_xen_configuration
+
 Python Runtime Libraries
 ========================
 
diff --git a/config/StdGNU.mk b/config/StdGNU.mk
index c6439f6..273f1e8 100644
--- a/config/StdGNU.mk
+++ b/config/StdGNU.mk
@@ -1,3 +1,17 @@
+# These are standard defaults which you can use to avoid having
+# to run ./configure -- you can use this to compile the hypervisor
+# and the mini os:
+#
+# make xen
+# sudo make -C xen install
+#
+# make -C extras/mini-os
+include $(XEN_ROOT)/config/defaults.mk
+
+# This comes from running configure and will override
+# the defaults.
+-include $(XEN_ROOT)/config/Toplevel.mk
+
 AS         = $(CROSS_COMPILE)as
 LD         = $(CROSS_COMPILE)ld
 ifeq ($(clang),y)
@@ -27,24 +41,10 @@ INSTALL_DIR  = $(INSTALL) -d -m0755 -p
 INSTALL_DATA = $(INSTALL) -m0644 -p
 INSTALL_PROG = $(INSTALL) -m0755 -p
 
-PREFIX ?= /usr
-BINDIR = $(PREFIX)/bin
 INCLUDEDIR = $(PREFIX)/include
-LIBEXEC = $(PREFIX)/lib/xen/bin
-SHAREDIR = $(PREFIX)/share
 MANDIR = $(SHAREDIR)/man
 MAN1DIR = $(MANDIR)/man1
 MAN8DIR = $(MANDIR)/man8
-SBINDIR = $(PREFIX)/sbin
-XENFIRMWAREDIR = $(PREFIX)/lib/xen/boot
-
-PRIVATE_PREFIX = $(LIBDIR)/xen
-PRIVATE_BINDIR = $(PRIVATE_PREFIX)/bin
-
-CONFIG_DIR = /etc
-XEN_LOCK_DIR = /var/lock
-XEN_RUN_DIR = /var/run/xen
-XEN_PAGING_DIR = /var/lib/xen/xenpaging
 
 SYSCONFIG_DIR = $(CONFIG_DIR)/$(CONFIG_LEAF_DIR)
 
diff --git a/config/Toplevel.mk.in b/config/Toplevel.mk.in
index 4db7eaf..fc2754c 100644
--- a/config/Toplevel.mk.in
+++ b/config/Toplevel.mk.in
@@ -1 +1,25 @@
 SUBSYSTEMS               := @SUBSYSTEMS@
+
+SBINDIR                  := @SBINDIR@
+BINDIR                   := @BINDIR@
+LIBEXEC                  := @LIBEXEC@
+
+SHAREDIR                 := @SHAREDIR@
+LIBDIR                   := @LIBDIR@
+
+XEN_RUN_DIR              := @XEN_RUN_DIR@
+XEN_LOG_DIR              := @XEN_LOG_DIR@
+XEN_LIB_STORED           := @XEN_LIB_STORED@
+
+CONFIG_DIR               := @CONFIG_DIR@
+XEN_LOCK_DIR             := @XEN_LOCK_DIR@
+XEN_PAGING_DIR           := @XEN_PAGING_DIR@
+
+PRIVATE_PREFIX           := @PRIVATE_PREFIX@
+PRIVATE_PREFIX           := @PKG_XEN_PREFIX@
+PRIVATE_BINDIR           := @PRIVATE_BINDIR@
+
+XENFIRMWAREDIR           := @XENFIRMWAREDIR@
+
+XEN_CONFIG_DIR           := @XEN_CONFIG_DIR@
+XEN_SCRIPT_DIR           := @XEN_SCRIPT_DIR@
diff --git a/config/defaults.mk b/config/defaults.mk
new file mode 100644
index 0000000..d1d3d5a
--- /dev/null
+++ b/config/defaults.mk
@@ -0,0 +1,21 @@
+# Build system defaults, in case you never ran ./configure, this is
+# supported to be able to build the xen hypervisor and the mini os:
+#
+# make xen
+# sudo make -C xen install
+#
+# make -C extras/mini-os
+PREFIX ?= /usr
+BINDIR = $(PREFIX)/bin
+LIBEXEC = $(PREFIX)/lib/xen/bin
+SHAREDIR = $(PREFIX)/share
+SBINDIR = $(PREFIX)/sbin
+XENFIRMWAREDIR = $(PREFIX)/lib/xen/boot
+
+PRIVATE_PREFIX = $(LIBDIR)/xen
+PRIVATE_BINDIR = $(PRIVATE_PREFIX)/bin
+
+CONFIG_DIR = /etc
+XEN_LOCK_DIR = /var/lock
+XEN_RUN_DIR = /var/run/xen
+XEN_PAGING_DIR = /var/lib/xen/xenpaging
diff --git a/config/xen-environment-header.in b/config/xen-environment-header.in
new file mode 100644
index 0000000..7dd7a53
--- /dev/null
+++ b/config/xen-environment-header.in
@@ -0,0 +1,13 @@
+#define SBINDIR "@SBINDIR@"
+#define BINDIR "@BINDIR@"
+#define LIBEXEC "@LIBEXEC@"
+#define LIBDIR "@LIBDIR@"
+#define SHAREDIR "@SHAREDIR@"
+
+#define PRIVATE_BINDIR "@PRIVATE_BINDIR@"
+#define XENFIRMWAREDIR "@XENFIRMWAREDIR@"
+#define XEN_CONFIG_DIR "@XEN_CONFIG_DIR@"
+#define XEN_SCRIPT_DIR "@XEN_SCRIPT_DIR@"
+#define XEN_LOCK_DIR "@XEN_LOCK_DIR@"
+#define XEN_RUN_DIR "@XEN_RUN_DIR@"
+#define XEN_PAGING_DIR "@XEN_PAGING_DIR@"
diff --git a/config/xen-environment-scripts.in b/config/xen-environment-scripts.in
new file mode 100644
index 0000000..9623231
--- /dev/null
+++ b/config/xen-environment-scripts.in
@@ -0,0 +1,15 @@
+SBINDIR="@SBINDIR@"
+BINDIR="@BINDIR@"
+LIBEXEC="@LIBEXEC@"
+LIBDIR="@LIBDIR@"
+SHAREDIR="@SHAREDIR@"
+
+PRIVATE_BINDIR="@PRIVATE_BINDIR@"
+XENFIRMWAREDIR="@XENFIRMWAREDIR@"
+XEN_CONFIG_DIR="@XEN_CONFIG_DIR@"
+XEN_SCRIPT_DIR="@XEN_SCRIPT_DIR@"
+XEN_LOCK_DIR="@XEN_LOCK_DIR@"
+XEN_LOG_DIR="@XEN_LOG_DIR@"
+XEN_LIB_STORED="@XEN_LIB_STORED@"
+XEN_RUN_DIR="@XEN_RUN_DIR@"
+XEN_PAGING_DIR="@XEN_PAGING_DIR@"
diff --git a/configure.ac b/configure.ac
index 6c14524..3f26a39 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5,12 +5,19 @@ AC_PREREQ([2.67])
 AC_INIT([Xen Hypervisor], m4_esyscmd([./version.sh ./xen/Makefile]),
     [xen-devel@lists.xen.org], [xen], [http://www.xen.org/])
 AC_CONFIG_SRCDIR([./xen/common/kernel.c])
-AC_CONFIG_FILES([./config/Toplevel.mk])
+AC_CONFIG_FILES([
+	config/Toplevel.mk
+	config/xen-environment-scripts
+	config/xen-environment-header
+])
 
 AC_CANONICAL_HOST
 
 m4_include([m4/features.m4])
 m4_include([m4/subsystem.m4])
+m4_include([m4/expand_config.m4])
+
+AX_XEN_EXPAND_CONFIG()
 
 dnl mini-os is only ported to certain platforms
 case "$host_cpu" in
diff --git a/m4/expand_config.m4 b/m4/expand_config.m4
new file mode 100644
index 0000000..717fcd1
--- /dev/null
+++ b/m4/expand_config.m4
@@ -0,0 +1,61 @@
+AC_DEFUN([AX_XEN_EXPAND_CONFIG], [
+dnl expand these early so we can use this for substitutions
+test "x$prefix" = "xNONE" && prefix=$ac_default_prefix
+test "x$exec_prefix" = "xNONE" && exec_prefix=$ac_default_prefix
+
+BINDIR=$prefix/bin
+AC_SUBST(BINDIR)
+
+SBINDIR=$prefix/sbin
+AC_SUBST(SBINDIR)
+
+dnl XXX: this should be changed to use the passed $libexec
+dnl but can be done as a second step
+LIBEXEC=$prefix/lib/xen/bin
+AC_SUBST(LIBEXEC)
+
+LIBDIR=`eval echo $libdir`
+AC_SUBST(LIBDIR)
+
+XEN_RUN_DIR=/var/run/xen
+AC_SUBST(XEN_RUN_DIR)
+
+XEN_LOG_DIR=/var/log/xen
+AC_SUBST(XEN_LOG_DIR)
+
+XEN_LIB_STORED=/var/lib/xenstored
+AC_SUBST(XEN_LIB_STORED)
+
+SHAREDIR=$prefix/share
+AC_SUBST(SHAREDIR)
+
+PRIVATE_PREFIX=$LIBDIR/xen
+AC_SUBST(PRIVATE_PREFIX)
+
+PKG_XEN_PREFIX=$LIBDIR/xen
+AC_SUBST(PKG_XEN_PREFIX)
+
+PRIVATE_BINDIR=$PRIVATE_PREFIX/bin
+AC_SUBST(PRIVATE_BINDIR)
+
+XENFIRMWAREDIR=$prefix/lib/xen/boot
+AC_SUBST(XENFIRMWAREDIR)
+
+CONFIG_DIR=/etc
+AC_SUBST(CONFIG_DIR)
+
+XEN_CONFIG_DIR=$CONFIG_DIR/xen
+AC_SUBST(XEN_CONFIG_DIR)
+
+XEN_SCRIPT_DIR=$XEN_CONFIG_DIR/scripts
+AC_SUBST(XEN_SCRIPT_DIR)
+
+XEN_LOCK_DIR=/var/lock
+AC_SUBST(XEN_LOCK_DIR)
+
+XEN_RUN_DIR=/var/run/xen
+AC_SUBST(XEN_RUN_DIR)
+
+XEN_PAGING_DIR=/var/lib/xen/xenpaging
+AC_SUBST(XEN_PAGING_DIR)
+])
diff --git a/stubdom/Makefile b/stubdom/Makefile
index c41de27..f0f624a 100644
--- a/stubdom/Makefile
+++ b/stubdom/Makefile
@@ -48,18 +48,19 @@ TARGET_LDFLAGS += -nostdlib -L$(CROSS_PREFIX)/$(GNU_TARGET_ARCH)-xen-elf/lib
 
 TARGETS=$(STUBDOM_TARGETS)
 
+STUBDOMPATH="stubdompath.sh"
+
+$(STUBDOMPATH): $(XEN_ROOT)/config/xen-environment-scripts
+	@cp $(XEN_ROOT)/config/xen-environment-scripts $@
+
 .PHONY: all
 all: build
 ifeq ($(STUBDOM_SUPPORTED),1)
-build: genpath $(STUBDOM_BUILD)
+build: $(STUBDOMPATH) $(STUBDOM_BUILD)
 else
-build: genpath
+build: $(STUBDOMPATH)
 endif
 
-STUBDOMPATH="stubdompath.sh"
-genpath-target = $(call buildmakevars2file,$(STUBDOMPATH))
-$(eval $(genpath-target))
-
 ##############
 # Cross-newlib
 ##############
@@ -448,9 +449,9 @@ xenstore-stubdom: mini-os-$(XEN_TARGET_ARCH)-xenstore libxc xenstore
 #########
 
 ifeq ($(STUBDOM_SUPPORTED),1)
-install: genpath install-readme $(STUBDOM_INSTALL)
+install: $(STUBDOMPATH) install-readme $(STUBDOM_INSTALL)
 else
-install: genpath
+install: $(STUBDOMPATH)
 endif
 
 install-readme:
diff --git a/stubdom/configure.ac b/stubdom/configure.ac
index 6468203..d6b0fbf 100644
--- a/stubdom/configure.ac
+++ b/stubdom/configure.ac
@@ -16,6 +16,9 @@ m4_include([../m4/features.m4])
 m4_include([../m4/path_or_fail.m4])
 m4_include([../m4/depends.m4])
 m4_include([../m4/fetcher.m4])
+m4_include([../m4/expand_config.m4])
+
+AX_XEN_EXPAND_CONFIG()
 
 # Enable/disable stub domains
 AX_STUBDOM_CONDITIONAL([ioemu-stubdom], [ioemu])
diff --git a/tools/configure.ac b/tools/configure.ac
index 25d7ca3..470894a 100644
--- a/tools/configure.ac
+++ b/tools/configure.ac
@@ -47,6 +47,9 @@ m4_include([../m4/ptyfuncs.m4])
 m4_include([../m4/extfs.m4])
 m4_include([../m4/fetcher.m4])
 m4_include([../m4/ax_compare_version.m4])
+m4_include([../m4/expand_config.m4])
+
+AX_XEN_EXPAND_CONFIG()
 
 # Enable/disable options
 AX_ARG_DEFAULT_DISABLE([githttp], [Download GIT repositories via HTTP])
diff --git a/tools/hotplug/common/Makefile b/tools/hotplug/common/Makefile
index 18d87aa..4a63f40 100644
--- a/tools/hotplug/common/Makefile
+++ b/tools/hotplug/common/Makefile
@@ -9,14 +9,14 @@ HOTPLUGPATH="hotplugpath.sh"
 XEN_SCRIPTS =
 XEN_SCRIPT_DATA = $(HOTPLUGPATH)
 
-genpath-target = $(call buildmakevars2file,$(HOTPLUGPATH))
-$(eval $(genpath-target))
+$(HOTPLUGPATH): $(XEN_ROOT)/config/xen-environment-scripts
+	@cp $(XEN_ROOT)/config/xen-environment-scripts $@
 
 .PHONY: all
 all: build
 
 .PHONY: build
-build: genpath
+build: $(HOTPLUGPATH)
 
 .PHONY: install
 install: all install-scripts
diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
index 4cfa275..fedfd62 100644
--- a/tools/libxl/Makefile
+++ b/tools/libxl/Makefile
@@ -97,6 +97,9 @@ TEST_PROGS += $(foreach t, $(LIBXL_TESTS),test_$t)
 
 $(LIBXL_OBJS) $(LIBXL_TEST_OBJS): CFLAGS += $(CFLAGS_LIBXL) -include $(XEN_ROOT)/tools/config.h
 
+_paths.h: $(XEN_ROOT)/config/xen-environment-header
+	@cp $(XEN_ROOT)/config/xen-environment-header $@
+
 AUTOINCS= libxlu_cfg_y.h libxlu_cfg_l.h _libxl_list.h _paths.h \
 	libxlu_disk_l.h _libxl_save_msgs_callout.h _libxl_save_msgs_helper.h
 AUTOSRCS= libxlu_cfg_y.c libxlu_cfg_l.c
@@ -141,9 +144,6 @@ $(LIBXL_OBJS) $(LIBXLU_OBJS) $(XL_OBJS) $(SAVE_HELPER_OBJS) \
 	@rm -f $*.[ch]
 	$(FLEX) --header-file=$*.h --outfile=$*.c $<
 
-genpath-target = $(call buildmakevars2file,_paths.h.tmp)
-$(eval $(genpath-target))
-
 libxl.api-ok: check-libxl-api-rules _libxl.api-for-check
 	$(PERL) $^
 	touch $@
@@ -154,11 +154,6 @@ _%.api-for-check: %.h $(AUTOINCS)
 		>$@.new
 	mv -f $@.new $@
 
-_paths.h: genpath
-	sed -e "s/\([^=]*\)=\(.*\)/#define \1 \2/g" $@.tmp >$@.2.tmp
-	rm -f $@.tmp
-	$(call move-if-changed,$@.2.tmp,$@)
-
 _libxl_list.h: $(XEN_INCLUDE)/xen-external/bsd-sys-queue-h-seddery $(XEN_INCLUDE)/xen-external/bsd-sys-queue.h
 	$(PERL) $^ --prefix=libxl >$@.new
 	$(call move-if-changed,$@.new,$@)
diff --git a/tools/python/Makefile b/tools/python/Makefile
index c433cbe..5556ffa 100644
--- a/tools/python/Makefile
+++ b/tools/python/Makefile
@@ -6,11 +6,11 @@ all: build
 
 XENPATH = "xen/util/path.py"
 
-genpath-target = $(call buildmakevars2file,$(XENPATH))
-$(eval $(genpath-target))
+$(XENPATH): $(XEN_ROOT)/config/xen-environment-scripts
+	@cp $(XEN_ROOT)/config/xen-environment-scripts $@
 
 .PHONY: build
-build: genpath genwrap.py $(XEN_ROOT)/tools/libxl/libxl_types.idl \
+build: $(XENPATH) genwrap.py $(XEN_ROOT)/tools/libxl/libxl_types.idl \
 		$(XEN_ROOT)/tools/libxl/idl.py
 	PYTHONPATH=$(XEN_ROOT)/tools/libxl $(PYTHON) genwrap.py \
 		$(XEN_ROOT)/tools/libxl/libxl_types.idl \
-- 
2.0.0.rc3.18.g00a5b79