dtc: Refactor Makefiles

This patch makes a number of Makefile cleanups and improvements:
	- We use more generic rules to invoke flex and bison, which is
useful for some of the other changes.
	- We use the name dtc-lexer.lex.c for the flex output, instead
of the default lex.yy.c.  That means less potential for confusion if
dtc is embedded into other projects (e.g. the kernel).
	- We separate out a Makefile.dtc designed for embedding into
other projects, analagous to Makefile.libfdt.
	- Makefile.libfdt is cleaned up to be more useful based on
some actual trial runs of embedding libfdt in the kernel bootwrapper.
	- Versioning related rules and variables are collected into
one place in the Makefile.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 24 insertions, 0 deletions

diff --git a/Makefile.dtc b/Makefile.dtc
new file mode 100644
index 0000000..c843ee2
--- /dev/null
+++ b/Makefile.dtc
@@ -0,0 +1,24 @@
+# Makefile.dtc
+#
+# This is not a complete Makefile of itself.  Instead, it is designed to
+# be easily embeddable into other systems of Makefiles.
+#
+DTC_SRCS = dtc.c flattree.c fstree.c data.c livetree.c treesource.c srcpos.c
+DTC_EXTRA = dtc.h srcpos.h
+DTC_LEXFILES = dtc-lexer.l
+DTC_BISONFILES = dtc-parser.y
+
+DTC_LEX_SRCS = $(DTC_LEXFILES:%.l=%.lex.c)
+DTC_BISON_SRCS = $(DTC_BISONFILES:%.y=%.tab.c)
+DTC_BISON_INCLUDES = $(DTC_BISONFILES:%.y=%.tab.h)
+
+DTC_GEN_SRCS = $(DTC_LEX_SRCS) $(DTC_BISON_SRCS)
+DTC_GEN_ALL = $(DTC_GEN_SRCS) $(DTC_BISON_INCLUDES)
+DTC_OBJS = $(DTC_SRCS:%.c=%.o) $(DTC_GEN_SRCS:%.c=%.o)
+
+DTC_CLEANFILES = $(DTC_GEN_ALL)
+
+# We assume the containing Makefile system can do auto-dependencies for most
+# things, but we supply the dependencies on generated header files explicitly
+
+$(addprefix $(DTC_objdir)/,$(DTC_GEN_SRCS:%.c=%.o)): $(addprefix $(DTC_objdir)/,$(DTC_BISON_INCLUDES))