Automatic dependencies in gnustep-make

[Malmberg]

Hi,

I've attached a small patch to rules.make that adds automatic dependency
tracking (a feature I've really missed). It's controlled by the
auto_dependencies variable, so 'make auto_dependencies=yes' would
activate it. Putting 'auto_dependencies=yes' in config.make makes it
active by default.

The patch relies on gcc doing the 'right thing' with -MMD, so it works
with v3, but not v2.95.2. The .d files (with dependency information) are
stored in $(GNUSTEP_OBJ_DIR). It works with c, obj-c, and c++ files, and
(as far as I can tell) with all types of projects. I'm no export on
gnustep-make internals, though, so comments would be appreciated.

(Note that you'll need to 'make clean' before using it in a project so
the .d files will be generated.)

- Alexander Malmberg

Index: rules.make
===================================================================
RCS file: /cvsroot/gnustep/gnustep/core/make/rules.make,v
retrieving revision 1.117
diff -u -r1.117 rules.make
--- rules.make  2001/11/13 15:09:07     1.117
+++ rules.make  2001/11/22 01:09:41
@@ -307,53 +307,60 @@
 # file.m_FILE_FILTER_OUT_FLAGS = -Wno-import
 #
 
+ifeq ($(auto_dependencies),yes)
+auto_dependencies_flag=-MMD -MP
+else
+auto_dependencies_flag=
+endif
+
 # Please don't be scared by the following rules ... In normal
 # situations, $<_FILTER_OUT_FLAGS is empty, and $<_FILE_FLAGS is empty
 # as well, so the following rule is simply equivalent to
 # $(CC) $< -c $(ALL_CPPFLAGS) $(ALL_CFLAGS) -o $@
 # and similarly all the rules below
 $(GNUSTEP_OBJ_DIR)/%${OEXT} : %.c
-       $(CC) $< -c \
+       $(CC) $< -c $(auto_dependencies_flag) \
              $(filter-out $($<_FILE_FILTER_OUT_FLAGS),$(ALL_CPPFLAGS) \
                                                        $(ALL_CFLAGS)) \
              $($<_FILE_FLAGS) -o $@
 
+
 $(GNUSTEP_OBJ_DIR)/%${OEXT} : %.m
-       $(CC) $< -c \
+       $(CC) $< -c $(auto_dependencies_flag) \
              $(filter-out $($<_FILE_FILTER_OUT_FLAGS),$(ALL_CPPFLAGS) \
                                                        $(ALL_OBJCFLAGS)) \
              $($<_FILE_FLAGS) -o $@
 
 $(GNUSTEP_OBJ_DIR)/%${OEXT} : %.C
-       $(CC) $< -c \
+       $(CC) $< -c $(auto_dependencies_flag) \
              $(filter-out $($<_FILE_FILTER_OUT_FLAGS),$(ALL_CPPFLAGS) \
                                                        $(ALL_CFLAGS)   \
                                                        $(ALL_CCFLAGS)) \
              $($<_FILE_FLAGS) -o $@
 
 $(GNUSTEP_OBJ_DIR)/%${OEXT} : %.cc
-       $(CC) $< -c \
+       $(CC) $< -c $(auto_dependencies_flag) \
              $(filter-out $($<_FILE_FILTER_OUT_FLAGS),$(ALL_CPPFLAGS) \
                                                        $(ALL_CFLAGS)   \
                                                        $(ALL_CCFLAGS)) \
              $($<_FILE_FLAGS) -o $@
 
 $(GNUSTEP_OBJ_DIR)/%${OEXT} : %.cpp
-       $(CC) $< -c \
+       $(CC) $< -c $(auto_dependencies_flag) \
              $(filter-out $($<_FILE_FILTER_OUT_FLAGS),$(ALL_CPPFLAGS) \
                                                        $(ALL_CFLAGS)   \
                                                        $(ALL_CCFLAGS)) \
              $($<_FILE_FLAGS) -o $@
 
 $(GNUSTEP_OBJ_DIR)/%${OEXT} : %.cxx
-       $(CC) $< -c \
+       $(CC) $< -c $(auto_dependencies_flag) \
              $(filter-out $($<_FILE_FILTER_OUT_FLAGS),$(ALL_CPPFLAGS) \
                                                        $(ALL_CFLAGS)   \
                                                        $(ALL_CCFLAGS)) \
              $($<_FILE_FLAGS) -o $@
 
 $(GNUSTEP_OBJ_DIR)/%${OEXT} : %.cp
-       $(CC) $< -c \
+       $(CC) $< -c $(auto_dependencies_flag) \
              $(filter-out $($<_FILE_FILTER_OUT_FLAGS),$(ALL_CPPFLAGS) \
                                                        $(ALL_CFLAGS)   \
                                                        $(ALL_CCFLAGS)) \
@@ -632,6 +639,12 @@
 # tool/app/whatever
 OBJ_FILES_TO_LINK = $(C_OBJ_FILES) $(OBJC_OBJ_FILES) $(CC_OBJ_FILES) \
                     $(SUBPROJECT_OBJ_FILES) $(OBJ_FILES)
+
+ifeq ($(auto_dependencies),yes)
+ifneq ($(strip $(OBJ_FILES_TO_LINK)),)
+-include $(addsuffix .d, $(basename $(OBJ_FILES_TO_LINK)))
+endif
+endif
 
 # If we are using Windows32 DLLs, for each library that we link
 # against, pass a -Dlib{library_name}_ISDLL=1 option to the