doc: rpc_list: improve DEFS parsing

When getting all the makefile variables from the Makefiles obey
also the conditionals (ifdef, ifndef) and make sure all the
makefiles rules are filtered out (to avoid miss-interpreting a
 shell variable assignment in a rule as a makefile variable).

doc/rpc_list/Makefile

@@ -137,13 +137,26 @@ get_make_idefs=$(subst ^LF^,$(LF),$(shell sed \
 
 
 # get all the lines from the makefile containing variable definitions.
+# It will also return conditionals and try to filter out possible rules.
 # WARNING: does not work with all sed implementation (tested with GNU sed).
 # It uses a hack to restore the LFs (LFs are removed by $(shell)): LFs are
 # replaced with '^LF^' and then ^LF^ is subst'ed back to a real LF.
-get_make_vars=$(subst ^LF^,$(LF),$(shell sed \
- -ne '/^[\t ]*[A-Za-z0-9_-]\+[\t ]*[+:]\?=.*[^\]$$/H'\
- -ne '/^[\t ]*[A-Za-z0-9_-]\+[\t ]*[+:]\?=.*\\$$/,/\(^$$\)\|\([^\]$$\)/H'\
- -ne '$${g;s/\n/^LF^/g;p}'\
+get_make_vars=$(subst ^LF^,$(LF),$(shell sed -n \
+ -e ': start' \
+ -e '/^\(ifeq\|ifneq\|else\|endif\)[\t ]*\($$\|.*[^\]$$\)/{H;d}' \
+ -e '/^\(ifeq\|ifneq\|else\|endif\)[\t ]\+.*[\]$$/,/[^\]$$/{H;d}' \
+ -e '/^[a-zA-Z._/$$][a-zA-Z0-9._()/$$ \t-]*:\([^=]\|$$\)/b eat_rule' \
+ -e '/^[\t ]*[A-Za-z._][A-Za-z0-9._-]*[\t ]*[+:]\?=.*[^\]$$/{H;d}' \
+ -e '/^[\t ]*[A-Za-z._][A-Za-z0-9._-]*[\t ]*[+:]\?=.*\\$$/,/\(^$$\)\|\([^\]$$\)/{H;d}' \
+ -e ': end' \
+ -e '$${g;s/\n/^LF^/g;p}'\
+ -e 'b' \
+ -e ': eat_rule' \
+ -e '$$b end' \
+ -e 'n' \
+ -e '/^[a-zA-Z._/$$][a-zA-Z0-9._()/$$ \t-]*:\([^=]\|$$\)/b eat_rule' \
+ -e '/^[\t]/b eat_rule' \
+ -e 'b start' \
 < $(1)/Makefile ))
 
 
@@ -159,6 +172,8 @@ INCLUDES:=
 # extract all the includes and defs from the module makefile and
 # evaluate them
 $$(eval $$(call get_make_vars,$$(dir $$(call get_prereq,$(1)))))
+# override COREPATH (we know better)
+COREPATH=../..
 # save the result in a per group e_idefs_<grp_name> var
 $$(eval e_idefs_$$(call get_grp,$(1)):=$$(DEFS) $$(INCLUDES))