From 7d47671b9d85d03ac2fa5d3b852a6e5073508aa8 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Sat, 18 Aug 2018 11:37:23 -0600
Subject: [PATCH] apps/builtin/Makefile:  Fix an error introduced with commit
 904d68cd1f7394b1c3cb6f0b67651aa4fbee5e62:  If there are no built-in
 functions, then the CATFILE function hangs.

---
 builtin/Makefile | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/builtin/Makefile b/builtin/Makefile
index 55386431d..492e91118 100644
--- a/builtin/Makefile
+++ b/builtin/Makefile
@@ -62,8 +62,8 @@ VPATH =
 
 # Registry entry lists
 
-PDATLIST = $(call RWILDCARD, registry, *.pdat)
-BDATLIST = $(call RWILDCARD, registry, *.bdat)
+PDATLIST = $(strip $(call RWILDCARD, registry, *.pdat))
+BDATLIST = $(strip $(call RWILDCARD, registry, *.bdat))
 
 # Build Targets
 
@@ -85,13 +85,17 @@ builtin_list$(OBJEXT): builtin_list.h builtin_proto.h
 builtin_list.h: registry$(DELIM).updated
 	$(call DELFILE, .xx_builtin_list.h)
 	$(Q) touch .xx_builtin_list.h
+ifneq ($(BDATLIST),)
 	$(call CATFILE, .xx_builtin_list.h, $(BDATLIST))
+endif
 	$(Q) mv .xx_builtin_list.h builtin_list.h
 
 builtin_proto.h: registry$(DELIM).updated
 	$(call DELFILE, .xx_builtin_proto.h)
 	$(Q) touch .xx_builtin_proto.h
+ifneq ($(PDATLIST),)
 	$(call CATFILE, .xx_builtin_proto.h, $(PDATLIST))
+endif
 	$(Q) mv .xx_builtin_proto.h builtin_proto.h
 
 .built: $(OBJS)