From 8b1ae48d7cc392bccdd67070b7c2c90aecf0c068 Mon Sep 17 00:00:00 2001
From: Seth Jennings <sjenning@redhat.com>
Date: Tue, 23 Sep 2014 09:45:04 -0500
Subject: [PATCH] improve kpatch-build Makefile

Right now, the makefile has one target, create-diff-object, which
contains all the source/headers as one long list and all the source
files compiled in one command to make create-diff-object.

This doesn't scale well and doesn't accurately portray the dependencies
of each object that contribute to the final binary.

This commit renames create-diff-object.c to main.c so that it can be
compiled and linked seperately and cleanly in Make and autogenerates
dependencies for each .o. This should make it easier to add additional
object files, or refactor the very large main.o into seperate object
file, later.
---
 .gitignore            |  1 +
 kpatch-build/Makefile | 15 ++++++++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/.gitignore b/.gitignore
index 01b74a7..cfb7038 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@
 *.ko.cmd
 *.mod.c
 *.swp
+*.d
 .tmp_versions
 Module.symvers
 kpatch-build/lookup
diff --git a/kpatch-build/Makefile b/kpatch-build/Makefile
index 6ac29d8..f8c7176 100644
--- a/kpatch-build/Makefile
+++ b/kpatch-build/Makefile
@@ -4,13 +4,18 @@ CFLAGS  += -I../kmod/patch -Iinsn -Wall -g
 LDFLAGS = -lelf
 
 TARGETS = create-diff-object
+OBJS = create-diff-object.o lookup.o insn/insn.o insn/inat.o
+SOURCES = create-diff-object.c lookup.c insn/insn.c insn/inat.c
 
 all: $(TARGETS)
 
-create-diff-object: create-diff-object.c list.h lookup.c lookup.h insn/insn.c \
-		    insn/inat.c insn/inat-tables.c insn/asm/inat.h \
-		    insn/asm/insn.h insn/asm/inat_types.h
-	$(CC) $(CFLAGS) create-diff-object.c lookup.c insn/insn.c insn/inat.c -o $@ $(LDFLAGS)
+-include $(SOURCES:.c=.d)
+
+%.o : %.c
+	$(CC) -MMD -MP $(CFLAGS) -c -o $@ $<
+
+create-diff-object: $(OBJS)
+	$(CC) $(CFLAGS) $^ -o $@ $(LDFLAGS)
 
 install: all
 	$(INSTALL) -d $(LIBEXECDIR)
@@ -23,4 +28,4 @@ uninstall:
 	$(RM) $(BINDIR)/kpatch-build
 
 clean:
-	$(RM) $(TARGETS)
+	$(RM) $(TARGETS) $(OBJS) *.d insn/*.d