infra: add force build flag for host dependencies

This commit adds a config option which will force buildroot to build all host dependencies even if they are already present on the host system. This may be a desirable option if different hosts are used to build the same source. In this case, some packages will be built on one host that are not built on another. This is problematic if build source archives are cached afterwards for offline builds. Cc: Peter Korsgaard <[email protected]> Signed-off-by: Bryce Ferguson <[email protected]> Signed-off-by: Matt Weber <[email protected]> [Peter: reword, drop exit 1, reshuffle] Signed-off-by: Peter Korsgaard <[email protected]>
ParzivalWolfram · Feb 4, 2019 · 3f1b965 · 3f1b965
1 parent 8e3c632
commit 3f1b965
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diff --git a/Config.in b/Config.in
@@ -677,6 +677,18 @@ config BR2_COMPILER_PARANOID_UNSAFE_PATH
 	  and external toolchain backends (through the toolchain
 	  wrapper).
 
+config BR2_FORCE_HOST_BUILD
+	bool "Force the building of host dependencies"
+	help
+	  Build all available host dependencies, even if they are
+	  already installed on the system.
+
+	  This option can be used to ensure that the download cache of
+	  source archives for packages remain consistent between
+	  different build hosts.
+
+	  This option will increase build time.
+
 config BR2_REPRODUCIBLE
 	bool "Make the build reproducible (experimental)"
 	# SOURCE_DATE_EPOCH support in toolchain-wrapper requires GCC 4.4

diff --git a/support/dependencies/dependencies.mk b/support/dependencies/dependencies.mk
@@ -5,13 +5,19 @@
 #
 ################################################################################
 
+ifeq ($(BR2_FORCE_HOST_BUILD),y)
+# ignore all available host packages
+define suitable-host-package
+endef
+else
 # suitable-host-pkg: calls check-host-$(1).sh shell script. Parameter (2)
 # can be the candidate to be checked. If not present, the check-host-$(1).sh
 # script should use 'which' to find a candidate. The script should return
 # the path to the suitable host tool, or nothing if no suitable tool was found.
 define suitable-host-package
 $(shell support/dependencies/check-host-$(1).sh $(2))
 endef
+endif
 # host utilities needs host-tar to extract the source code tarballs, so
 # ensure check-host-tar.mk is included before the rest
 include support/dependencies/check-host-tar.mk