[xen master] xen/build: include include/config/auto.conf in main Makefile

[patchbot@xxxxxxx]

commit 6c122d3984a5efb1f187cde0e478e4e346202f2b
Author:     Anthony PERARD <anthony.perard@xxxxxxxxxx>
AuthorDate: Thu Apr 23 09:59:27 2020 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Apr 23 09:59:27 2020 +0200

    xen/build: include include/config/auto.conf in main Makefile
    
    We are going to generate the CFLAGS early from "xen/Makefile" instead
    of in "Rules.mk", but we need to include "config/auto.conf", so
    include it in "Makefile".
    
    Before including "config/auto.conf" we check which make target a user
    is calling, as some targets don't need "auto.conf". For targets that
    needs auto.conf, make will generate it (and a default .config if
    missing).
    
    root-make-done is to avoid doing the calculation again once Rules.mk
    takes over and is been executed with the root Makefile. When Rules.mk
    is including xen/Makefile, `config-build' and `need-config' are
    undefined so auto.conf will not be included again (it is already
    included by Rules.mk) and kconfig target are out of reach of Rules.mk.
    
    We are introducing a target %config to catch all targets for kconfig.
    So we need an extra target %/.config to prevent make from trying to
    regenerate $(XEN_ROOT)/.config that is included in Config.mk.
    
    The way targets are filtered is inspired by Kbuild, with some code
    imported from Linux. That's why there is PHONY variable that isn't
    used yet, for example.
    
    Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/Makefile | 101 +++++++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 78 insertions(+), 23 deletions(-)

diff --git a/xen/Makefile b/xen/Makefile
index e5f7b1ae13..643c689658 100644
--- a/xen/Makefile
+++ b/xen/Makefile
@@ -49,7 +49,76 @@ default: build
 .PHONY: dist
 dist: install
 
-build install:: include/config/auto.conf
+
+ifneq ($(root-make-done),y)
+# section to run before calling Rules.mk, but only once.
+#
+# To make sure we do not include .config for any of the *config targets
+# catch them early, and hand them over to tools/kconfig/Makefile
+
+clean-targets := %clean
+no-dot-config-targets := $(clean-targets) \
+                         uninstall debug cloc \
+                         cscope TAGS tags MAP gtags \
+                         xenversion
+
+config-build    := n
+need-config     := y
+
+ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
+    ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
+        need-config := n
+    endif
+endif
+
+ifneq ($(filter %config,$(MAKECMDGOALS)),)
+    config-build := y
+endif
+
+export root-make-done := y
+endif # root-make-done
+
+include scripts/Kbuild.include
+
+# Shorthand for kconfig
+kconfig = -f $(BASEDIR)/tools/kconfig/Makefile.kconfig ARCH=$(ARCH) 
SRCARCH=$(SRCARCH) HOSTCC="$(HOSTCC)" HOSTCXX="$(HOSTCXX)"
+
+ifeq ($(config-build),y)
+# ===========================================================================
+# *config targets only - make sure prerequisites are updated, and descend
+# in tools/kconfig to make the *config target
+
+config: FORCE
+       $(MAKE) $(kconfig) $@
+
+# Config.mk tries to include .config file, don't try to remake it
+%/.config: ;
+
+%config: FORCE
+       $(MAKE) $(kconfig) $@
+
+else # !config-build
+
+ifeq ($(need-config),y)
+include include/config/auto.conf
+# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
+# changes are detected.
+include include/config/auto.conf.cmd
+
+# Allow people to just run `make` as before and not force them to configure
+$(KCONFIG_CONFIG):
+       $(MAKE) $(kconfig) defconfig
+
+# The actual configuration files used during the build are stored in
+# include/generated/ and include/config/. Update them if .config is newer than
+# include/config/auto.conf (which mirrors .config).
+#
+# This exploits the 'multi-target pattern rule' trick.
+# The syncconfig should be executed only once to make all the targets.
+include/config/%.conf include/config/%.conf.cmd: $(KCONFIG_CONFIG)
+       $(MAKE) $(kconfig) syncconfig
+
+endif # need-config
 
 .PHONY: build install uninstall clean distclean MAP
 build install uninstall debug clean distclean MAP::
@@ -254,9 +323,6 @@ cscope:
 _MAP:
        $(NM) -n $(TARGET)-syms | grep -v '\(compiled\)\|\(\.o$$\)\|\( [aUw] 
\)\|\(\.\.ng$$\)\|\(LASH[RL]DI\)' > System.map
 
-.PHONY: FORCE
-FORCE:
-
 %.o %.i %.s: %.c FORCE
        $(MAKE) -f $(BASEDIR)/Rules.mk -C $(*D) $(@F)
 
@@ -277,25 +343,6 @@ $(foreach base,arch/x86/mm/guest_walk_% \
                arch/x86/mm/shadow/guest_%, \
     $(foreach ext,o i s,$(call build-intermediate,$(base).$(ext))))
 
-kconfig := oldconfig config menuconfig defconfig allyesconfig allnoconfig \
-       nconfig xconfig gconfig savedefconfig listnewconfig olddefconfig \
-       randconfig $(notdir $(wildcard arch/$(SRCARCH)/configs/*_defconfig))
-.PHONY: $(kconfig)
-$(kconfig):
-       $(MAKE) -f $(BASEDIR)/tools/kconfig/Makefile.kconfig ARCH=$(ARCH) 
SRCARCH=$(SRCARCH) HOSTCC="$(HOSTCC)" HOSTCXX="$(HOSTCXX)" $@
-
-include/config/%.conf: include/config/auto.conf.cmd $(KCONFIG_CONFIG)
-       $(MAKE) -f $(BASEDIR)/tools/kconfig/Makefile.kconfig ARCH=$(ARCH) 
SRCARCH=$(SRCARCH) HOSTCC="$(HOSTCC)" HOSTCXX="$(HOSTCXX)" syncconfig
-
-# Allow people to just run `make` as before and not force them to configure
-$(KCONFIG_CONFIG):
-       $(MAKE) -f $(BASEDIR)/tools/kconfig/Makefile.kconfig ARCH=$(ARCH) 
SRCARCH=$(SRCARCH) HOSTCC="$(HOSTCC)" HOSTCXX="$(HOSTCXX)" defconfig
-
-# Break the dependency chain for the first run
-include/config/auto.conf.cmd: ;
-
--include $(BASEDIR)/include/config/auto.conf.cmd
-
 .PHONY: cloc
 cloc:
        $(eval tmpfile := $(shell mktemp))
@@ -307,3 +354,11 @@ cloc:
        cloc --list-file=$(tmpfile)
        rm $(tmpfile)
 
+endif #config-build
+
+PHONY += FORCE
+FORCE:
+
+# Declare the contents of the PHONY variable as phony.  We keep that
+# information in a variable so we can use it in if_changed and friends.
+.PHONY: $(PHONY)
--
generated by git-patchbot for /home/xen/git/xen.git#master