depends: create a hostid and buildid and add option for salts

These add very simple sanity checks to ensure that the build/host toolchains
have not changed since the last run. If they have, all ids will change and
packages will be rebuilt.

For more complicated usage (like parsing dpkg), HOST_ID_SALT/BUILD_ID_SALT may
be used to introduce arbitrary data to the ids.

depends/Makefile

@@ -15,6 +15,8 @@ BASEDIR = $(CURDIR)
 HASH_LENGTH:=11
 DOWNLOAD_CONNECT_TIMEOUT:=10
 DOWNLOAD_RETRIES:=3
+HOST_ID_SALT ?= salt
+BUILD_ID_SALT ?= salt
 
 host:=$(BUILD)
 ifneq ($(HOST),)
@@ -73,6 +75,20 @@ include builders/$(build_os).mk
 include builders/default.mk
 include packages/packages.mk
 
+build_id_string:=$(BUILD_ID_SALT)
+build_id_string+=$(shell $(build_CC) --version 2>/dev/null)
+build_id_string+=$(shell $(build_AR) --version 2>/dev/null)
+build_id_string+=$(shell $(build_CXX) --version 2>/dev/null)
+build_id_string+=$(shell $(build_RANLIB) --version 2>/dev/null)
+build_id_string+=$(shell $(build_STRIP) --version 2>/dev/null)
+
+$(host_arch)_$(host_os)_id_string:=$(HOST_ID_SALT)
+$(host_arch)_$(host_os)_id_string+=$(shell $(host_CC) --version 2>/dev/null)
+$(host_arch)_$(host_os)_id_string+=$(shell $(host_AR) --version 2>/dev/null)
+$(host_arch)_$(host_os)_id_string+=$(shell $(host_CXX) --version 2>/dev/null)
+$(host_arch)_$(host_os)_id_string+=$(shell $(host_RANLIB) --version 2>/dev/null)
+$(host_arch)_$(host_os)_id_string+=$(shell $(host_STRIP) --version 2>/dev/null)
+
 qt_packages_$(NO_QT) = $(qt_packages) $(qt_$(host_os)_packages)
 qt_native_packages_$(NO_QT) = $(qt_native_packages)
 wallet_packages_$(NO_WALLET) = $(wallet_packages)
@@ -90,7 +106,7 @@ include funcs.mk
 
 toolchain_path=$($($(host_arch)_$(host_os)_native_toolchain)_prefixbin)
 final_build_id_long+=$(shell $(build_SHA256SUM) config.site.in)
-final_build_id+=$(shell echo -n $(final_build_id_long) | $(build_SHA256SUM) | cut -c-$(HASH_LENGTH))
+final_build_id+=$(shell echo -n "$(final_build_id_long)" | $(build_SHA256SUM) | cut -c-$(HASH_LENGTH))
 $(host_prefix)/.stamp_$(final_build_id): $(native_packages) $(packages)
 	$(AT)rm -rf $(@D)
 	$(AT)mkdir -p $(@D)

depends/README.md

@@ -38,6 +38,8 @@ The following can be set when running make: make FOO=bar
     NO_WALLET: Don't download/build/cache libs needed to enable the wallet
     NO_UPNP: Don't download/build/cache packages needed for enabling upnp
     DEBUG: disable some optimizations and enable more runtime checking
+    HOST_ID_SALT: Optional salt to use when generating host package ids
+    BUILD_ID_SALT: Optional salt to use when generating build package ids
 
 If some packages are not built, for example `make NO_WALLET=1`, the appropriate
 options will be passed to bitcoin's configure. In this case, `--disable-wallet`.

depends/funcs.mk

@@ -39,7 +39,7 @@ define int_get_build_id
 $(eval $(1)_dependencies += $($(1)_$(host_arch)_$(host_os)_dependencies) $($(1)_$(host_os)_dependencies))
 $(eval $(1)_all_dependencies:=$(call int_get_all_dependencies,$(1),$($($(1)_type)_native_toolchain) $($(1)_dependencies)))
 $(foreach dep,$($(1)_all_dependencies),$(eval $(1)_build_id_deps+=$(dep)-$($(dep)_version)-$($(dep)_recipe_hash)))
-$(eval $(1)_build_id_long:=$(1)-$($(1)_version)-$($(1)_recipe_hash)-$(release_type) $($(1)_build_id_deps))
+$(eval $(1)_build_id_long:=$(1)-$($(1)_version)-$($(1)_recipe_hash)-$(release_type) $($(1)_build_id_deps) $($($(1)_type)_id_string))
 $(eval $(1)_build_id:=$(shell echo -n "$($(1)_build_id_long)" | $(build_SHA256SUM) | cut -c-$(HASH_LENGTH)))
 final_build_id_long+=$($(package)_build_id_long)