[source] tools: reorganize dependencies, fix build after deleting staging dir

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/a9232ba1ed461adf8ac610edf95ea6ba9963ea34

commit a9232ba1ed461adf8ac610edf95ea6ba9963ea34
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Sat Jan 7 18:25:33 2017 +0100

    tools: reorganize dependencies, fix build after deleting staging dir
    
    A lot of packages (especially those using libtool) depend on sed being
    available. xz fails on an incremental build pretty early if it's not
    there.
    
    Clean up handling if essential core tools (patch, tar, xz), build them
    in parallel and make them depend on sed
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 tools/Makefile     | 27 +++++++++++++++------------
 tools/sed/Makefile |  3 +++
 2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/tools/Makefile b/tools/Makefile
index 4300d0e..6879e3b 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -22,10 +22,10 @@ ifneq ($(CONFIG_SDK)$(CONFIG_PACKAGE_kmod-b43)$(CONFIG_PACKAGE_b43legacy-firmwar
 endif
 
 tools-$(BUILD_TOOLCHAIN) += gmp mpfr mpc libelf expat
-tools-y += m4 libtool autoconf automake flex bison pkg-config sed mklibs
+tools-y += m4 libtool autoconf automake flex bison pkg-config mklibs
 tools-y += sstrip make-ext4fs e2fsprogs mtd-utils mkimage
-tools-y += firmware-utils patch-image patch quilt yaffs2 padjffs2
-tools-y += mm-macros missing-macros xz cmake scons bc findutils gengetopt patchelf
+tools-y += firmware-utils patch-image quilt yaffs2 padjffs2
+tools-y += mm-macros missing-macros cmake scons bc findutils gengetopt patchelf
 tools-y += mtools dosfstools libressl
 tools-$(CONFIG_TARGET_orion_generic) += wrt350nv2-builder upslug2
 tools-$(CONFIG_powerpc) += upx
@@ -42,18 +42,16 @@ tools-$(CONFIG_TARGET_apm821xx) += genext2fs
 # builddir dependencies
 $(curdir)/bison/compile := $(curdir)/flex/install
 $(curdir)/flex/compile := $(curdir)/libtool/install
-$(curdir)/pkg-config/compile := $(curdir)/sed/install
-$(curdir)/libtool/compile := $(curdir)/sed/install $(curdir)/m4/install $(curdir)/autoconf/install $(curdir)/automake/install $(curdir)/missing-macros/install
+$(curdir)/libtool/compile := $(curdir)/m4/install $(curdir)/autoconf/install $(curdir)/automake/install $(curdir)/missing-macros/install
 $(curdir)/squashfs/compile := $(curdir)/lzma-old/install
 $(curdir)/squashfs4/compile := $(curdir)/xz/install
-$(curdir)/quilt/compile := $(curdir)/sed/install $(curdir)/autoconf/install $(curdir)/findutils/install
+$(curdir)/quilt/compile := $(curdir)/autoconf/install $(curdir)/findutils/install
 $(curdir)/autoconf/compile := $(curdir)/m4/install
 $(curdir)/automake/compile := $(curdir)/m4/install $(curdir)/autoconf/install $(curdir)/pkg-config/install $(curdir)/xz/install
 $(curdir)/gmp/compile := $(curdir)/libtool/install
 $(curdir)/mpc/compile := $(curdir)/mpfr/install $(curdir)/gmp/install
 $(curdir)/mpfr/compile := $(curdir)/gmp/install
 $(curdir)/mtd-utils/compile := $(curdir)/e2fsprogs/install
-$(curdir)/mkimage/compile := $(curdir)/sed/install
 $(curdir)/mklibs/compile := $(curdir)/libtool/install
 $(curdir)/qemu/compile := $(curdir)/e2fsprogs/install
 $(curdir)/upslug2/compile := $(curdir)/libtool/install
@@ -88,14 +86,19 @@ endif
 # dependency for tools which have patches directory
 $(foreach tool, $(tools-y), $(if $(wildcard $(curdir)/$(tool)/patches),$(eval $(curdir)/$(tool)/compile += $(curdir)/patch/install)))
 
-# make any tool (except xz itself) depend on XZ to ensure that *.tar.xz source archives can be unpacked
 $(foreach tool, $(filter-out xz,$(tools-y)), $(eval $(curdir)/$(tool)/compile += $(curdir)/xz/install))
 
-$(foreach tool, $(tools-y), $(eval $(curdir)/$(tool)/compile += $(curdir)/tar/install))
-tools-y += tar
+# make any tool depend on tar, xz and patch to ensure that archives can be unpacked and patched properly
+tools-core := tar xz patch
 
-$(curdir)/tar/compile := $(curdir)/flock/install
-tools-y += flock
+$(foreach tool, $(tools-y), $(eval $(curdir)/$(tool)/compile += $(patsubst %,$(curdir)/%/install,$(tools-core))))
+tools-y += $(tools-core)
+
+# make core tools depend on sed and flock
+$(foreach tool, $(tools-core), $(eval $(curdir)/$(tool)/compile += $(curdir)/sed/install))
+
+$(curdir)/sed/compile := $(curdir)/flock/install
+tools-y += flock sed
 
 $(curdir)/builddirs := $(tools-y) $(tools-dep) $(tools-)
 $(curdir)/builddirs-default := $(tools-y)
diff --git a/tools/sed/Makefile b/tools/sed/Makefile
index 332ec09..9ff2e66 100644
--- a/tools/sed/Makefile
+++ b/tools/sed/Makefile
@@ -17,6 +17,9 @@ export SED:=
 
 HOST_BUILD_PARALLEL:=1
 
+HOSTCC := $(HOSTCC_NOCACHE)
+HOSTCXX := $(HOSTCXX_NOCACHE)
+
 include $(INCLUDE_DIR)/host-build.mk
 
 HOST_CONFIGURE_ARGS += \