[Buildroot] [PATCH 2 of 3 v2] dependencies: build a host-tar if no suitable tar can be found
Thomas De Schampheleire
patrickdepinguin+buildroot at gmail.com
Wed Nov 23 13:59:59 UTC 2011
Some toolchains, like the one built with buildroot itself, use hardlinks (for
example to link between the c++ and g++ binary). Unpacking such a toolchain
with the --strip-components options does not work correctly if the system tar
is too old (<1.17). Even recent releases of RedHat/CentOS still ship with
tar 1.15.
This patch checks for a suitable tar version (tar 1.17+) on the host system,
and adds host-tar to the host dependencies if none can be found.
TAR is redefined to HOST_TAR, except when extracting host-tar (this is a
chicken-and-egg problem), so that all packages use the host-tar if no suitable
tar was found.
Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire at gmail.com>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
---
package/Makefile.package.in | 12 ------------
package/tar/tar.mk | 6 ++++++
toolchain/dependencies/check-host-tar.mk | 32 ++++++++++++++++++++++++++++++++
toolchain/dependencies/check-host-tar.sh | 29 +++++++++++++++++++++++++++++
4 files changed, 67 insertions(+), 12 deletions(-)
diff --git a/package/Makefile.package.in b/package/Makefile.package.in
--- a/package/Makefile.package.in
+++ b/package/Makefile.package.in
@@ -235,18 +235,6 @@ define DOWNLOAD
exit 1
endef
-# Utility programs used to build packages
-TAR ?= tar
-
-# Automatically detect tar --strip-path/components option
-TAR_STRIP_COMPONENTS := \
- $(shell $(TAR) --help | grep strip-path > /dev/null ; \
- if test $$? = 0 ; then \
- echo '--strip-path' ; \
- else \
- echo '--strip-components' ; \
- fi)
-
# Needed for the foreach loops to loop over the list of hooks, so that
# each hook call is properly separated by a newline.
define sep
diff --git a/package/tar/tar.mk b/package/tar/tar.mk
--- a/package/tar/tar.mk
+++ b/package/tar/tar.mk
@@ -13,3 +13,9 @@ TAR_DEPENDENCIES += busybox
endif
$(eval $(call AUTOTARGETS))
+
+TAR = $(SYSTEM_TAR) # We need a real tar to extract tar
+TAR_STRIP_COMPONENTS = $(SYSTEM_TAR_STRIP_COMPONENTS)
+$(eval $(call AUTOTARGETS,host))
+TAR = $(HOST_TAR)
+TAR_STRIP_COMPONENTS = $(HOST_TAR_STRIP_COMPONENTS)
diff --git a/toolchain/dependencies/check-host-tar.mk b/toolchain/dependencies/check-host-tar.mk
new file mode 100644
--- /dev/null
+++ b/toolchain/dependencies/check-host-tar.mk
@@ -0,0 +1,32 @@
+TAR ?= tar
+
+# To extract tar, we always need a real (system) tar. Provide the necessary
+# definitions here to avoid cluttering package/tar/tar.mk .
+# TAR will be overridden again when the tar .mk file is included, so we must
+# finalize the value of SYSTEM_TAR by using :=
+SYSTEM_TAR := $(TAR)
+# Automatically detect tar --strip-path/components option
+# --strip-path was renamed to --strip-components in tar 1.15
+SYSTEM_TAR_STRIP_COMPONENTS := \
+ $(shell $(SYSTEM_TAR) --help | grep strip-path > /dev/null ; \
+ if test $$? = 0 ; then \
+ echo '--strip-path' ; \
+ else \
+ echo '--strip-components' ; \
+ fi)
+
+# Determine correct HOST_TAR
+ifneq (,$(call suitable-host-package,tar))
+ HOST_TAR = $(SYSTEM_TAR)
+else
+ DEPENDENCIES_HOST_PREREQ += host-tar
+ HOST_TAR = $(HOST_DIR)/usr/bin/tar
+endif
+
+# Since HOST_TAR is at least 1.17, it will certainly support --strip-components
+HOST_TAR_STRIP_COMPONENTS = --strip-components
+
+# Set definitions used by all .mk files included after this one and before
+# package/tar/tar.mk
+TAR = $(HOST_TAR)
+TAR_STRIP_COMPONENTS = $(HOST_TAR_STRIP_COMPONENTS)
diff --git a/toolchain/dependencies/check-host-tar.sh b/toolchain/dependencies/check-host-tar.sh
new file mode 100755
--- /dev/null
+++ b/toolchain/dependencies/check-host-tar.sh
@@ -0,0 +1,29 @@
+#!/bin/sh
+
+tar=`which tar`
+if [ -z "$tar" ]; then
+ return
+fi
+
+# Output of 'tar --version' examples:
+# tar (GNU tar) 1.15.1
+# tar (GNU tar) 1.25
+version=`$tar --version | head -n 1 | sed 's/^.*\s\([0-9]\+\.\S\+\).*$/\1/'`
+major=`echo "$version" | cut -d. -f1`
+minor=`echo "$version" | cut -d. -f2`
+bugfix=`echo "$version" | cut -d. -f3`
+
+# Minimal version = 1.17 (previous versions do not correctly unpack archives
+# containing hard-links if the --strip-components option is used).
+major_min=1
+minor_min=17
+if [ $major -gt $major_min ]; then
+ echo $tar
+else
+ if [ $major -eq $major_min -a $minor -ge $minor_min ]; then
+ echo $tar
+ else
+ false
+ # echo nothing: no suitable tar found
+ fi
+fi
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