[xen master] libs/light: Rework targets prerequisites

[patchbot@xxxxxxx]

commit a2a5d091d0ca78c6a9346c8d4bb8cddc37a07375
Author:     Anthony PERARD <anthony.perard@xxxxxxxxxx>
AuthorDate: Wed Feb 8 09:21:11 2023 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Feb 8 09:21:11 2023 +0100

    libs/light: Rework targets prerequisites
    
    No need for $(AUTOSRCS), GNU make can generate them as needed when
    trying to build them as needed when trying to build the object. Also,
    those two AUTOSRCS don't need to be a prerequisite of "all". As for
    the "clean" target, those two files are already removed via "_*.c".
    
    We don't need $(AUTOINCS) either:
    - As for both _libxl_save_msgs*.h headers, we are adding more
      selective dependencies so the headers will still be generated as
      needed.
    - "clean" rule already delete the _*.h files, so AUTOINCS aren't needed
      there.
    
    "libxl_internal_json.h" doesn't seems to have ever existed, so the
    dependency is removed.
    
    Rework objects prerequisites, to have them dependents on either
    "libxl.h" or "libxl_internal.h". "libxl.h" is not normally included
    directly in the source code as "libxl_internal.h" is used instead, but
    we have "libxl.h" as prerequisite of "libxl_internal.h", so generated
    headers will still be generated as needed.
    
    Make doesn't need "libxl.h" to generate "testidl.c", "libxl.h" is only
    needed later when building "testidl.o". This avoid the need to
    regenerate "testidl.c" when only "libxl.h" changed. Also use automatic
    variables $< and $@.
    
    Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
    Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
---
 tools/libs/light/Makefile | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/tools/libs/light/Makefile b/tools/libs/light/Makefile
index cd3fa855e1..b28447a2ae 100644
--- a/tools/libs/light/Makefile
+++ b/tools/libs/light/Makefile
@@ -148,9 +148,6 @@ LIBXL_TEST_OBJS += $(foreach t, 
$(LIBXL_TESTS_INSIDE),libxl_test_$t.opic)
 TEST_PROG_OBJS += $(foreach t, $(LIBXL_TESTS_PROGS),test_$t.o) test_common.o
 TEST_PROGS += $(foreach t, $(LIBXL_TESTS_PROGS),test_$t)
 
-AUTOINCS = _libxl_save_msgs_callout.h _libxl_save_msgs_helper.h
-AUTOSRCS = _libxl_save_msgs_callout.c _libxl_save_msgs_helper.c
-
 CLIENTS = testidl libxl-save-helper
 
 SAVE_HELPER_OBJS = libxl_save_helper.o _libxl_save_msgs_helper.o
@@ -178,13 +175,13 @@ libxl_x86_acpi.o libxl_x86_acpi.opic: CFLAGS += 
-I$(XEN_ROOT)/tools
 $(SAVE_HELPER_OBJS): CFLAGS += $(CFLAGS_libxenctrl) $(CFLAGS_libxenevtchn) 
$(CFLAGS_libxenguest)
 
 testidl.o: CFLAGS += $(CFLAGS_libxenctrl) $(CFLAGS_libxenlight)
-testidl.c: libxl_types.idl gentest.py $(XEN_INCLUDE)/libxl.h $(AUTOINCS)
-       $(PYTHON) gentest.py libxl_types.idl testidl.c.new
-       mv testidl.c.new testidl.c
+testidl.c: libxl_types.idl gentest.py
+       $(PYTHON) gentest.py $< $@.new
+       mv -f $@.new $@
 
-all: $(CLIENTS) $(TEST_PROGS) $(AUTOSRCS) $(AUTOINCS)
+all: $(CLIENTS) $(TEST_PROGS)
 
-$(OBJS-y) $(PIC_OBJS) $(SAVE_HELPER_OBJS) $(LIBXL_TEST_OBJS) 
$(TEST_PROG_OBJS): $(AUTOINCS) libxl.api-ok
+$(OBJS-y) $(PIC_OBJS) $(SAVE_HELPER_OBJS) $(LIBXL_TEST_OBJS) 
$(TEST_PROG_OBJS): libxl.api-ok
 
 $(DSDT_FILES-y): acpi
 
@@ -196,7 +193,7 @@ libxl.api-ok: check-libxl-api-rules _libxl.api-for-check
        $(PERL) $^
        touch $@
 
-_libxl.api-for-check: $(XEN_INCLUDE)/libxl.h $(AUTOINCS)
+_libxl.api-for-check: $(XEN_INCLUDE)/libxl.h
        $(CC) $(CPPFLAGS) $(CFLAGS) -c -E $< $(APPEND_CFLAGS) \
                -DLIBXL_EXTERNAL_CALLERS_ONLY=LIBXL_EXTERNAL_CALLERS_ONLY \
                >$@.new
@@ -208,14 +205,22 @@ _libxl_save_msgs_helper.h _libxl_save_msgs_callout.h: \
        $(PERL) -w $< $@ >$@.new
        $(call move-if-changed,$@.new,$@)
 
+#
+# headers dependencies on generated headers
+#
 $(XEN_INCLUDE)/libxl.h: $(XEN_INCLUDE)/_libxl_types.h
 $(XEN_INCLUDE)/libxl_json.h: $(XEN_INCLUDE)/_libxl_types_json.h
 libxl_internal.h: $(XEN_INCLUDE)/libxl.h $(XEN_INCLUDE)/libxl_json.h
 libxl_internal.h: _libxl_types_internal.h _libxl_types_private.h 
_libxl_types_internal_private.h
-libxl_internal_json.h: _libxl_types_internal_json.h
+libxl_internal.h: _libxl_save_msgs_callout.h
 
-$(OBJS-y) $(PIC_OBJS) $(LIBXL_TEST_OBJS) $(TEST_PROG_OBJS) 
$(SAVE_HELPER_OBJS): $(XEN_INCLUDE)/libxl.h
+#
+# objects dependencies on headers that depends on generated headers
+#
+$(TEST_PROG_OBJS): $(XEN_INCLUDE)/libxl.h
 $(OBJS-y) $(PIC_OBJS) $(LIBXL_TEST_OBJS): libxl_internal.h
+$(SAVE_HELPER_OBJS): $(XEN_INCLUDE)/libxl.h _libxl_save_msgs_helper.h
+testidl.o: $(XEN_INCLUDE)/libxl.h
 
 # This exploits the 'multi-target pattern rule' trick.
 # gentypes.py should be executed only once to make all the targets.
@@ -262,5 +267,4 @@ clean::
        $(RM) testidl.c.new testidl.c *.api-ok
        $(RM) $(TEST_PROGS) libxenlight_test.so libxl_test_*.opic
        $(RM) -r __pycache__
-       $(RM) $(AUTOSRCS) $(AUTOINCS)
        $(MAKE) -C $(ACPI_PATH) ACPI_BUILD_DIR=$(CURDIR) clean
--
generated by git-patchbot for /home/xen/git/xen.git#master