makefiles: move extra deps into new MOD vars

To make the makefiles more similar.

That is, add the following new variables:

* MOD_HDRS
* MOD_SRCS
* MOD_OBJS

And move existing module-specific header and object dependencies into
`MOD_HDRS` and `MOD_OBJS`, respectively.  `MOD_SRCS` is added mostly for
symmetry/consistency.

Note: Use `MOD_` as a prefix instead of `EXTRA_` to avoid confusion, as
the latter is currently used for global variables (such as
`EXTRA_CFLAGS`), as opposed to module-specific variables.

Note2: Add them directly into the HDRS/SRCS/OBJS variables to avoid
cluttering the existing recipes with an extra variables unnecessarily.
This also allows, for example, referencing all of the object
dependencies with `$<` if `$(OBJS)` is the first dependency (at least in
GNU make).

Note3: Since HDRS/SRCS/OBJS use simple assignment (through `:=`), the
MOD variables should appear before including src/common.mk (or
src/so.mk).

1 files changed, 6 insertions, 4 deletions

diff --git a/src/libpostexecseccomp/Makefile b/src/libpostexecseccomp/Makefile
index c0cab45fb..870c32891 100644
--- a/src/libpostexecseccomp/Makefile
+++ b/src/libpostexecseccomp/Makefile
@@ -1,16 +1,18 @@
 ROOT = ../..
 -include $(ROOT)/config.mk
 
-HDRS := $(sort $(wildcard *.h))
-SRCS := $(sort $(wildcard *.c))
-OBJS := $(SRCS:.c=.o)
+MOD_HDRS = ../include/seccomp.h ../include/rundefs.h
+
+HDRS := $(sort $(wildcard *.h)) $(MOD_HDRS)
+SRCS := $(sort $(wildcard *.c)) $(MOD_SRCS)
+OBJS := $(SRCS:.c=.o) $(MOD_OBJS)
 CFLAGS += -ggdb $(HAVE_FATAL_WARNINGS) -O2 -DVERSION='"$(VERSION)"' -fstack-protector-all -D_FORTIFY_SOURCE=2 -fPIC -Wformat -Wformat-security
 LDFLAGS += -pie -fPIE -Wl,-z,relro -Wl,-z,now
 
 .PHONY: all
 all: libpostexecseccomp.so
 
-%.o : %.c $(HDRS) ../include/seccomp.h ../include/rundefs.h $(ROOT)/config.mk
+%.o : %.c $(HDRS) $(ROOT)/config.mk
         $(CC) $(CFLAGS) $(INCLUDE) -c $< -o $@
 
 libpostexecseccomp.so: $(OBJS) $(ROOT)/config.mk