build: make find_md5 reproducible with AUTOREMOVE

While experimenting with the AUTOREMOVE option in search of a way to use
prebuilt host tools in different buildroot, it was discovered that the
md5 generated by find_md5 in depends.mk is not reproducible.

Currently the hash is generated by the path of the file in addition to
the file mod time. Out of confusion, probably, there was an idea that
such command was used on the package build_dir. Reality is that this
command is run on the package files. (Makefile, patches, src)

This is problematic because the package Makefile (for example) change at
each git clone and base the hash on the Makefile mtime doesn't really
reflect if the Makefile actually changes across a buildroot or not.

A better approach is to generate an hash of each file and then generate
an hash on the sort hash list. This way we remove the problem of git
clone setting a wrong mtime while keeping the integrity of checking if a
file changed for the package as any change will result in a different
hash.

Introduce a new kind of find_md5 function, find_md5_reproducible that
apply this new logic and limit it only with AUTOREMOVE option set to
prevent any kind of slowdown due to additional hash generation.

(cherry picked from commit 53a08e37437972ba0a8fbf953a93a70a6b784ef4)
[ reworked mkhash to old implementation ]
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

diff --git a/include/depends.mk b/include/depends.mk
index 0080b97876f7bf5b6f7b923aa46ac868ba2b1181..7b87f2643fbca34d0631dbd21a72882c4df77f3a 100644 (file)
--- a/include/depends.mk
+++ b/include/depends.mk
@@ -12,6 +12,7 @@
 DEP_FINDPARAMS := -x "*/.svn*" -x ".*" -x "*:*" -x "*\!*" -x "* *" -x "*\\\#*" -x "*/.*_check" -x "*/.*.swp" -x "*/.pkgdir*"
 
 find_md5=find $(wildcard $(1)) -type f $(patsubst -x,-and -not -path,$(DEP_FINDPARAMS) $(2)) -printf "%p%T@\n" | sort | mkhash md5
+find_md5_reproducible=find $(wildcard $(1)) -type f $(patsubst -x,-and -not -path,$(DEP_FINDPARAMS) $(2)) -print0 | xargs -0 mkhash md5 | sort | mkhash md5
 
 define rdep
   .PRECIOUS: $(2)

diff --git a/include/host-build.mk b/include/host-build.mk
index e4a5c48e72f6f0a91acb558e94eec265b0bb0d5d..36b3fed1f32f4cf6932252b38f47fe6c23007834 100644 (file)
--- a/include/host-build.mk
+++ b/include/host-build.mk
@@ -21,7 +21,7 @@ include $(INCLUDE_DIR)/depends.mk
 include $(INCLUDE_DIR)/quilt.mk
 
 BUILD_TYPES += host
-HOST_STAMP_PREPARED=$(HOST_BUILD_DIR)/.prepared$(if $(HOST_QUILT)$(DUMP),,$(shell $(call find_md5,${CURDIR} $(PKG_FILE_DEPENDS),))_$(call confvar,CONFIG_AUTOREMOVE $(HOST_PREPARED_DEPENDS)))
+HOST_STAMP_PREPARED=$(HOST_BUILD_DIR)/.prepared$(if $(HOST_QUILT)$(DUMP),,$(shell $(call $(if $(CONFIG_AUTOREMOVE),find_md5_reproducible,find_md5),${CURDIR} $(PKG_FILE_DEPENDS),))_$(call confvar,CONFIG_AUTOREMOVE $(HOST_PREPARED_DEPENDS)))
 HOST_STAMP_CONFIGURED:=$(HOST_BUILD_DIR)/.configured
 HOST_STAMP_BUILT:=$(HOST_BUILD_DIR)/.built
 HOST_BUILD_PREFIX?=$(if $(IS_PACKAGE_BUILD),$(STAGING_DIR_HOSTPKG),$(STAGING_DIR_HOST))

diff --git a/include/kernel-build.mk b/include/kernel-build.mk
index 66a9f64c802959061bceae23266688cbeb91b439..1f440f9ee0c6e94ea344e8ba12c68692b6d551ea 100644 (file)
--- a/include/kernel-build.mk
+++ b/include/kernel-build.mk
@@ -10,7 +10,7 @@ ifneq ($(DUMP),1)
 endif
 
 KERNEL_FILE_DEPENDS=$(GENERIC_BACKPORT_DIR) $(GENERIC_PATCH_DIR) $(GENERIC_HACK_DIR) $(PATCH_DIR) $(GENERIC_FILES_DIR) $(FILES_DIR)
-STAMP_PREPARED=$(LINUX_DIR)/.prepared$(if $(QUILT)$(DUMP),,_$(shell $(call find_md5,$(KERNEL_FILE_DEPENDS),)))
+STAMP_PREPARED=$(LINUX_DIR)/.prepared$(if $(QUILT)$(DUMP),,_$(shell $(call $(if $(CONFIG_AUTOREMOVE),find_md5_reproducible,find_md5),$(KERNEL_FILE_DEPENDS),)))
 STAMP_CONFIGURED:=$(LINUX_DIR)/.configured
 include $(INCLUDE_DIR)/download.mk
 include $(INCLUDE_DIR)/quilt.mk

diff --git a/include/package.mk b/include/package.mk
index db0a869dab62b9b914a069796d1d8dc69091e77e..389ba4243be3dc2c0ea1e5fc1d791da33db5e28f 100644 (file)
--- a/include/package.mk
+++ b/include/package.mk
@@ -84,7 +84,7 @@ ifneq ($(PREV_STAMP_PREPARED),)
   STAMP_PREPARED:=$(PREV_STAMP_PREPARED)
   CONFIG_AUTOREBUILD:=
 else
-  STAMP_PREPARED=$(PKG_BUILD_DIR)/.prepared$(if $(QUILT)$(DUMP),,_$(shell $(call find_md5,${CURDIR} $(PKG_FILE_DEPENDS),))_$(call confvar,CONFIG_AUTOREMOVE $(PKG_PREPARED_DEPENDS)))
+  STAMP_PREPARED=$(PKG_BUILD_DIR)/.prepared$(if $(QUILT)$(DUMP),,_$(shell $(call $(if $(CONFIG_AUTOREMOVE),find_md5_reproducible,find_md5),${CURDIR} $(PKG_FILE_DEPENDS),))_$(call confvar,CONFIG_AUTOREMOVE $(PKG_PREPARED_DEPENDS)))
 endif
 STAMP_CONFIGURED=$(PKG_BUILD_DIR)/.configured$(if $(DUMP),,_$(call confvar,$(PKG_CONFIG_DEPENDS)))
 STAMP_CONFIGURED_WILDCARD=$(PKG_BUILD_DIR)/.configured_*