Do not require external vppapigen when not cross-compiling

Change-Id: I80b8348ed4efd53d292c37a1ff69c13ee4741986
Signed-off-by: Damjan Marion <damarion@cisco.com>

5 files changed, 28 insertions, 11 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 0fc437a46aa..bba90eaebf8 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -102,7 +102,6 @@ api_DATA = \
 	$(patsubst %.api,%.api.json,$(API_FILES))
 
 BUILT_SOURCES += \
-	$(patsubst %.api,%.api.json,$(API_FILES)) \
 	$(patsubst %.api,%.api.h,$(API_FILES))
 
 endif # if ENABLE_VLIB
diff --git a/src/configure.ac b/src/configure.ac
index 4ed5570516a..eb380d8bf20 100644
--- a/src/configure.ac
+++ b/src/configure.ac
@@ -11,6 +11,8 @@ AM_PROG_AS
 AM_PROG_LIBTOOL
 AC_PROG_YACC
 
+AM_CONDITIONAL([CROSSCOMPILE], [test "$cross_compiling" == "yes"])
+
 ###############################################################################
 # Macros
 ###############################################################################
@@ -172,6 +174,20 @@ AM_COND_IF([ENABLE_G2],
   PKG_CHECK_MODULES(g2, gtk+-2.0)
 ])
 
+# If cross-compiling, we need external vppapigen and we cannot continue without it
+# For native builds, we just set dependency on vpppaigen binary in top_builddir
+AM_COND_IF([CROSSCOMPILE],
+[
+  AC_PATH_PROG([VPPAPIGEN], [vppapigen], [no])
+  if test "$VPPAPIGEN" = "no"; then
+    AC_MSG_ERROR([Externaly built vppapigen is needed when cross-compiling...])
+  fi
+],[
+  VPPAPIGEN=\$\(top_builddir\)/vppapigen
+])
+AC_SUBST([VPPAPIGEN])
+
+
 ###############################################################################
 # JAVA
 ###############################################################################
diff --git a/src/plugins/Makefile.am b/src/plugins/Makefile.am
index 987310b7b40..3e9ab91cd24 100644
--- a/src/plugins/Makefile.am
+++ b/src/plugins/Makefile.am
@@ -73,6 +73,5 @@ api_DATA = \
 	$(patsubst %.api,%.api.json,$(API_FILES))
 
 BUILT_SOURCES += \
-	$(patsubst %.api,%.api.json,$(API_FILES)) \
 	$(patsubst %.api,%.api.h,$(API_FILES))
 
diff --git a/src/suffix-rules.mk b/src/suffix-rules.mk
index f97b22764cc..9115c55b567 100644
--- a/src/suffix-rules.mk
+++ b/src/suffix-rules.mk
@@ -14,14 +14,14 @@
 # Shared suffix rules
 # Please do not set "SUFFIXES = .api.h .api" here
 
-%.api.h: %.api
+%.api.h: %.api @VPPAPIGEN@
 	@echo "  APIGEN  " $@ ;					\
 	mkdir -p `dirname $@` ;					\
-	$(CC) $(CPPFLAGS) -E -P -C -x c $^			\
-	| vppapigen --input - --output $@ --show-name $@ > /dev/null
+	$(CC) $(CPPFLAGS) -E -P -C -x c $<			\
+	| @VPPAPIGEN@ --input - --output $@ --show-name $@ > /dev/null
 
-%.api.json: %.api
+%.api.json: %.api @VPPAPIGEN@
 	@echo "  JSON API" $@ ;					\
 	mkdir -p `dirname $@` ;					\
-	$(CC) $(CPPFLAGS) -E -P -C -x c $^			\
-	| vppapigen --input - --json $@ > /dev/null
+	$(CC) $(CPPFLAGS) -E -P -C -x c $<			\
+	| @VPPAPIGEN@ --input - --json $@ > /dev/null
diff --git a/src/vppapigen.am b/src/vppapigen.am
index edde339d451..3207c83a325 100644
--- a/src/vppapigen.am
+++ b/src/vppapigen.am
@@ -13,14 +13,17 @@
 
 bin_PROGRAMS += vppapigen
 
-BUILT_SOURCES += tools/vppapigen/gram.h
+# We cannot rely on BUILT_SOURCES here as other built sources are relying
+# on vppapigen, so make can start compiling lex.c before gram.h is created.
+# This way we introduce new dependency by running C preprocessor.
 
-tools/vppapigen/gram.h: tools/vppapigen/gram.y
+tools/vppapigen/lex_e.c: tools/vppapigen/lex.c tools/vppapigen/gram.y
 	@$(YACC) -d @srcdir@/tools/vppapigen/gram.y
 	@mv y.tab.h tools/vppapigen/gram.h
 	@rm y.tab.c
+	@$(CC) -I. -E -o $@ $<
 
-vppapigen_SOURCES = tools/vppapigen/gram.y tools/vppapigen/lex.c tools/vppapigen/node.c
+vppapigen_SOURCES = tools/vppapigen/gram.y tools/vppapigen/lex_e.c tools/vppapigen/node.c
 vppapigen_LDADD = libvppinfra.la
 vppapigen_LDFLAGS = -static