Re: [PATCH v3 7/8] mk: sort object files when building deps lists
From: Luca Boccassi <hidden>
Date: 2017-06-27 10:43:52
On Tue, 2017-06-27 at 01:20 +0200, Thomas Monjalon wrote:
23/06/2017 20:41, lboccass@brocade.com:quoted
From: Luca Boccassi <redacted> In order to achieve reproducible builds, always use the same order when listing object files to build dependencies lists. Signed-off-by: Luca Boccassi <redacted> --- mk/rte.app.mk | 4 ++-- mk/rte.hostapp.mk | 4 ++-- mk/rte.shared.mk | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-)--- a/mk/rte.app.mk +++ b/mk/rte.app.mk@@ -263,8 +263,8 @@ LDLIBS_NAMES += $(patsubst -Wl$(comma)-l%,lib%.a,$(filter -Wl$(comma)-l%,$(LDLIB # list of found libraries files (useful for deps). If not found, the # library is silently ignored and dep won't be checked -LDLIBS_FILES := $(wildcard $(foreach dir,$(LDLIBS_PATH),\ - $(addprefix $(dir)/,$(LDLIBS_NAMES)))) +LDLIBS_FILES := $(sort $(wildcard $(foreach dir,$(LDLIBS_PATH),\ + $(addprefix $(dir)/,$(LDLIBS_NAMES)))))You cannot sort libraries. Check - for instance - this comment above in this file: # Eliminate duplicates without sorting, only keep the last occurrence filter-libs = \
Not sure I follow - what's the reason for avoiding to sort the list of libs to link against?
Why sorting them? What is random in libraries list?
The issue is that the output of wildcard is not fully deterministic. It can depend on the filesystem, and even on the locale settings [1]. Before GNU Make 3.82 (2009) it used to automatically sort the output, but that was removed (to make it faster... sigh). [2] -- Kind regards, Luca Boccassi [1] https://reproducible-builds.org/docs/stable-inputs/ [2] http://comments.gmane.org/gmane.comp.gnu.make.bugs/4260