8007639: Workaround for ccache in vm.make is incorrect

Summary: Fixed makefile logic to correctly special case JRE_RELEASE_VERSION and vm_version.o
Reviewed-by: dholmes, erikj

make/bsd/makefiles/vm.make

@@ -94,7 +94,12 @@ CXXFLAGS =           \
 # This is VERY important! The version define must only be supplied to vm_version.o
 # If not, ccache will not re-use the cache at all, since the version string might contain
 # a time and date. 
-vm_version.o: CXXFLAGS += ${JRE_VERSION} 
+CXXFLAGS/vm_version.o += ${JRE_VERSION}
+
+CXXFLAGS/BYFILE = $(CXXFLAGS/$@)
+
+# File specific flags
+CXXFLAGS += $(CXXFLAGS/BYFILE)
 
 ifdef DEFAULT_LIBPATH
 CXXFLAGS += -DDEFAULT_LIBPATH="\"$(DEFAULT_LIBPATH)\""

make/linux/makefiles/vm.make

@@ -100,7 +100,13 @@ CXXFLAGS =           \
 # This is VERY important! The version define must only be supplied to vm_version.o
 # If not, ccache will not re-use the cache at all, since the version string might contain
 # a time and date. 
-vm_version.o: CXXFLAGS += ${JRE_VERSION}
+CXXFLAGS/vm_version.o += ${JRE_VERSION}
+
+CXXFLAGS/BYFILE = $(CXXFLAGS/$@)
+
+# File specific flags
+CXXFLAGS += $(CXXFLAGS/BYFILE)
+
 
 ifndef JAVASE_EMBEDDED 
 ifneq (${ARCH},arm)

make/solaris/makefiles/vm.make

@@ -88,7 +88,13 @@ CXXFLAGS =           \
 # This is VERY important! The version define must only be supplied to vm_version.o
 # If not, ccache will not re-use the cache at all, since the version string might contain
 # a time and date. 
-vm_version.o: CXXFLAGS += ${JRE_VERSION} 
+CXXFLAGS/vm_version.o += ${JRE_VERSION}
+
+CXXFLAGS/BYFILE = $(CXXFLAGS/$@)
+
+# File specific flags
+CXXFLAGS += $(CXXFLAGS/BYFILE)
+
 
 # CFLAGS_WARN holds compiler options to suppress/enable warnings.
 CFLAGS += $(CFLAGS_WARN)