build: Tell make(1) that the compiler creates .d files.

[osl.git] / Makefile

diff --git a/Makefile b/Makefile
index fb8a01d3282a6fddf3a7b4866a0af198ab0dd2f6..2ebb0debe99bacd4087a765a62322f415ac85b24 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -83,12 +83,20 @@ ifeq ($(findstring clean, $(MAKECMDGOALS)),)
 -include $(deps)
 endif
 
-# List osl.h in the prerequisites to make sure we generate it before attempting
-# to run the compiler. This matters only when the .d file does not exist.
-%.o: %.c osl.h Makefile errtab.h
+# The files to generate before attempting to run the compiler. These
+# are the order-only prerequisites in the rule below.
+pre_deps := osl.h errtab.h oslfsck.lsg.h
+
+# The .d and .o files are both created from a single cc invocation.
+define CC_CMD
        $(CC) $(OSL_CPPFLAGS) $(CPPFLAGS) \
-               -c -MMD -MF $(*F).d -MT $@ \
+               -c -MMD -MF $(*F).d -MT $(*F).o \
                $(OSL_CFLAGS) $(CFLAGS) $<
+endef
+%.o: %.c Makefile | $(pre_deps)
+       $(CC_CMD)
+%.d: %.c Makefile | $(pre_deps)
+       $(CC_CMD)
 
 fsck.o: oslfsck.lsg.h
 oslfsck: $(fsck_objects)