build: fix protobuf out-of-tree build

Otherwise it aborts with "File does not reside within any path specified
using --proto_path (or -I)"

Signed-off-by: David Lamparter <[email protected]>

Author: eqvinox

grpc/subdir.am

@@ -23,12 +23,12 @@ EXTRA_DIST += grpc/frr-northbound.proto
 
 AM_V_PROTOC = $(am__v_PROTOC_$(V))
 am__v_PROTOC_ = $(am__v_PROTOC_$(AM_DEFAULT_VERBOSITY))
-am__v_PROTOC_0 = @echo "  PROTOC" $@;
+am__v_PROTOC_0 = @echo "  PROTOC  " $@;
 am__v_PROTOC_1 =
 
 SUFFIXES += .pb.h .pb.cc .grpc.pb.cc
 
 .proto.pb.cc:
-	$(AM_V_PROTOC)$(PROTOC) -I$(top_srcdir) --cpp_out=$(top_srcdir) $(top_srcdir)/$^
+	$(AM_V_PROTOC)$(PROTOC) -I$(top_srcdir) --cpp_out=$(top_builddir) $^
 .proto.grpc.pb.cc:
-	$(AM_V_PROTOC)$(PROTOC) -I$(top_srcdir) --grpc_out=$(top_srcdir) --plugin=protoc-gen-grpc=`which grpc_cpp_plugin` $(top_srcdir)/$^
+	$(AM_V_PROTOC)$(PROTOC) -I$(top_srcdir) --grpc_out=$(top_builddir) --plugin=protoc-gen-grpc=`which grpc_cpp_plugin` $^

qpb/subdir.am

@@ -35,15 +35,15 @@ if HAVE_PROTOBUF
 
 # Rules
 .proto.pb.h:
-	$(PROTOC) -I$(top_srcdir) --cpp_out=$(top_srcdir) $(top_srcdir)/$^
+	$(PROTOC) -I$(top_srcdir) --cpp_out=$(top_builddir) $^
 
 AM_V_PROTOC_C = $(am__v_PROTOC_C_$(V))
 am__v_PROTOC_C_ = $(am__v_PROTOC_C_$(AM_DEFAULT_VERBOSITY))
 am__v_PROTOC_C_0 = @echo "  PROTOC_C" $@;
 am__v_PROTOC_C_1 =
 
 .proto.pb-c.c:
-	$(AM_V_PROTOC_C)$(PROTOC_C) -I$(top_srcdir) --c_out=$(top_srcdir) $(top_srcdir)/$^
+	$(AM_V_PROTOC_C)$(PROTOC_C) -I$(top_srcdir) --c_out=$(top_builddir) $^
 .pb-c.c.pb-c.h:
 	@/bin/true