From 37904cc91a712f27a739319fd9bb99a8fcc819d7 Mon Sep 17 00:00:00 2001
From: Kir Kolyshkin <kir@openvz.org>
Date: Fri, 24 Mar 2017 15:07:42 -0700
Subject: [PATCH] criu/pie/Makefile: simplify and fix

The way criu/pie/Makefile is currently written, ld is run twice:

 1. link $(NAME-obj-y) objects to NAME.built-in.o

 2. link NAME.built-in.o, pie.lib.a, and compel plugins
    to NAME.built-in.bin.o (with compel ldflags and linker script)

There is absolutely no need for such two-stage linking, but it was OK.
It is not OK now, as "compel ldflags" for ARM doesn't need -r, and we
can't run the first stage with -r and the second stage without it.

So, let's simplify linking using a single ld invocation. This is my
third attempt in doing it, I think I nailed it this time -- it is now
clean and (relatively) simple.

While at it:
 - fix compel linker script dependency (it was not working);
 - rearrange the Makefile so variables goes first, then rules;
 - remove a comment about mount implementation in restorer.

NOTE that compel is called with ./ prefix so the file paths it prints
are also prefixed with ./, which is needed for objectify macro to ignore
those.

Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
---
 Makefile.compel   |  2 +-
 criu/pie/Makefile | 81 ++++++++++++++++++++---------------------------
 2 files changed, 35 insertions(+), 48 deletions(-)

diff --git a/Makefile.compel b/Makefile.compel
index ab479f79d..50124351d 100644
--- a/Makefile.compel
+++ b/Makefile.compel
@@ -1,4 +1,4 @@
-COMPEL_BIN		:= compel/compel-host
+COMPEL_BIN		:= ./compel/compel-host
 export COMPEL_BIN
 
 COMPEL_VERSION_HEADER	:= compel/include/version.h
diff --git a/criu/pie/Makefile b/criu/pie/Makefile
index 711d83a60..6a4fba9c1 100644
--- a/criu/pie/Makefile
+++ b/criu/pie/Makefile
@@ -1,7 +1,25 @@
-target		+= parasite restorer
+target		:= parasite restorer
+
+CFLAGS		:= $(filter-out -pg $(CFLAGS-GCOV) $(CFLAGS-ASAN),$(CFLAGS))
+ccflags-y	+= $(COMPEL_UAPI_INCLUDES)
+ccflags-y	+= -DCR_NOGLIBC
+ccflags-y	+= -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0
+ccflags-y	+= -Wp,-U_FORTIFY_SOURCE -Wp,-D_FORTIFY_SOURCE=0
+
+ifneq ($(filter-out clean mrproper,$(MAKECMDGOALS)),)
+	CFLAGS		+= $(shell $(COMPEL_BIN) cflags)
+	LDFLAGS		+= $(shell $(COMPEL_BIN) ldflags)
+	compel_plugins	:= $(shell $(COMPEL_BIN) plugins)
+endif
+
+ifeq ($(SRCARCH),arm)
+	ccflags-y	+= -marm
+endif
+
+asflags-y	+= -D__ASSEMBLY__
+
+LDS		:= compel/arch/$(SRCARCH)/scripts/compel-pack.lds.S
 
-parasite-obj-y	+= parasite.o
-restorer-obj-y	+= restorer.o
 restorer-obj-y	+= ./$(ARCH_DIR)/restorer.o
 
 ifeq ($(ARCH),x86)
@@ -11,51 +29,20 @@ ifeq ($(ARCH),x86)
         endif
 endif
 
-#
-# We can't provide proper mount implementation
-# in parasite code -- it requires run-time rellocation
-# applications, which is not the target of the
-# project.
-#
-CFLAGS		:= $(filter-out -pg $(CFLAGS-GCOV),$(CFLAGS))
-CFLAGS		:= $(filter-out $(CFLAGS-ASAN),$(CFLAGS))
+define gen-pie-rules
+$(1)-obj-y	+= $(1).o
+$(1)-obj-e	+= pie.lib.a
+$(1)-obj-e	+= $$(compel_plugins)
 
-ccflags-y	+= $(COMPEL_UAPI_INCLUDES)
-ccflags-y	+= -DCR_NOGLIBC
-ccflags-y	+= -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0
-ccflags-y	+= -Wp,-U_FORTIFY_SOURCE -Wp,-D_FORTIFY_SOURCE=0
+# Dependency on compel linker script, to relink if it has changed
+$$(obj)/$(1).built-in.o: $$(LDS)
 
-ifneq ($(filter-out clean mrproper,$(MAKECMDGOALS)),)
-        CFLAGS	+= $(shell $(COMPEL_BIN) cflags)
-	compel_std	:= $(shell $(COMPEL_BIN) plugins)
-endif
+$$(obj)/$(1)-blob.h: $$(obj)/$(1).built-in.o
+	$$(call msg-gen, $$@)
+	$$(Q) $$(COMPEL_BIN) hgen -f $$< -o $$@
 
-ifeq ($(SRCARCH),arm)
-        ccflags-y	+= -marm
-endif
+all-y		+= $$(obj)/$(1)-blob.h
+cleanup-y	+= $$(obj)/$(1)-blob.h
+endef
 
-asflags-y	+= -D__ASSEMBLY__
-
-BLOBS		+= $(obj)/restorer-blob.h $(obj)/parasite-blob.h
-LDS		:= compel/arch/$(SRCARCH)/scripts/compel-pack.lds.S
-
-.SECONDARY:
-
-target-name = $(patsubst criu/pie/%-blob.h,%,$(1))
-
-$(obj)/%.build-in.bin.o: $(LDS)
-$(obj)/%.built-in.bin.o: $(obj)/%.built-in.o $(obj)/pie.lib.a $(compel_std)
-	$(call msg-gen, $@)
-	$(Q) $(LD) $(shell $(COMPEL_BIN) ldflags) -o $@ $^
-
-$(obj)/%-blob.h: $(obj)/%.built-in.bin.o
-	$(call msg-gen, $@)
-	$(Q) $(COMPEL_BIN) hgen -f $< -o $@
-
-all-y += $(BLOBS)
-# blobs and pields are in cleanup, rather than in mrproper because
-# we want them to be re-generated after `make clean && make`
-cleanup-y += $(BLOBS)
-cleanup-y += $(obj)/*.bin
-cleanup-y += $(obj)/*.built-in.bin.o
-cleanup-y += $(obj)/*.built-in.bin
+$(foreach t,$(target),$(eval $(call gen-pie-rules,$(t))))