[js] Improve default for JSENGINE

Previously the default was always "node", even if nodejs wasn't
detected by configure.  This leads to a confusing failure from
"make check" if you have another support JS engine installed
but not node.

Now the default it picked based on which engines configure
found.  If only one was detected, that should be used.  If
multiple are, you can override the default choice by specifying
e.g. ENGINE=jsc on the make command line.

Fixes #2453

3 files changed, 40 insertions, 17 deletions

diff --git a/Examples/Makefile.in b/Examples/Makefile.in
index d69e20ca8..0849597a9 100644
--- a/Examples/Makefile.in
+++ b/Examples/Makefile.in
@@ -687,16 +687,34 @@ JSINCLUDES = @JSCOREINC@ @JSV8INC@
 JSDYNAMICLINKING = @JSCOREDYNAMICLINKING@ @JSV8DYNAMICLINKING@
 NODEJS = @NODEJS@
 NODEGYP = @NODEGYP@
+ifneq (, $(ENGINE))
+    JSENGINE=$(ENGINE)
+else
+ifneq (, $(NODEJS))
+    JSENGINE=node
+else
+ifneq (, @JSCENABLED@)
+    JSENGINE=jsc
+else
+ifneq (, @JSV8ENABLED@)
+    JSENGINE=v8
+else
+    # Shouldn't happen, but avoid empty value if it does.
+    JSENGINE=node
+endif
+endif
+endif
+endif
 
 # ----------------------------------------------------------------
 # Creating and building Javascript wrappers
 # ----------------------------------------------------------------
 
 javascript_wrapper:
-	$(SWIG) -javascript $(SWIGOPT) -o $(INTERFACEDIR)$(TARGET)_wrap.c $(INTERFACEPATH)
+	$(SWIG) -javascript $(SWIGOPT) -$(JSENGINE) -o $(INTERFACEDIR)$(TARGET)_wrap.c $(INTERFACEPATH)
 
 javascript_wrapper_cpp: $(SRCDIR_SRCS)
-	$(SWIG) -javascript -c++ $(SWIGOPT) -o $(INTERFACEDIR)$(TARGET)_wrap.cxx $(INTERFACEPATH)
+	$(SWIG) -javascript -c++ $(SWIGOPT) -$(JSENGINE) -o $(INTERFACEDIR)$(TARGET)_wrap.cxx $(INTERFACEPATH)
 
 javascript_build: $(SRCDIR_SRCS)
 	$(CC) -c $(CCSHARED) $(CPPFLAGS) $(CFLAGS) $(ISRCS) $(SRCDIR_SRCS) $(INCLUDES) $(JSINCLUDES)
diff --git a/Examples/javascript/example.mk b/Examples/javascript/example.mk
index 3ef012aa8..cce99fa25 100644
--- a/Examples/javascript/example.mk
+++ b/Examples/javascript/example.mk
@@ -1,12 +1,6 @@
 # Note: as a convention an example must be in a child directory of this.
 # These paths are relative to such an example directory
 
-ifneq (, $(ENGINE))
-	JSENGINE=$(ENGINE)
-else
-	JSENGINE=node
-endif
-
 ifneq (, $(V8_VERSION))
 	JSV8_VERSION=$(V8_VERSION)
 else
@@ -19,10 +13,10 @@ SWIGEXE        = $(SWIG_TOP)/swig
 SWIG_LIB_DIR   = $(SWIG_TOP)/$(TOP_BUILDDIR_TO_TOP_SRCDIR)Lib
 TARGET         = example
 INTERFACE      = example.i
-SWIGOPT        = -$(JSENGINE) -DV8_VERSION=$(JSV8_VERSION)
+SWIGOPT        = -DV8_VERSION=$(JSV8_VERSION)
 
 check: build
-	$(MAKE) -f $(EXAMPLES_TOP)/Makefile SRCDIR='$(SRCDIR)' JSENGINE='$(JSENGINE)' TARGET='$(TARGET)' javascript_run
+	$(MAKE) -f $(EXAMPLES_TOP)/Makefile SRCDIR='$(SRCDIR)' TARGET='$(TARGET)' javascript_run
 
 build:
 	$(MAKE) -f $(EXAMPLES_TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(SRCS)' \
@@ -30,7 +24,7 @@ build:
 	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' javascript_wrapper_cpp
 	$(MAKE) -f $(EXAMPLES_TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(SRCS)' \
 	SWIG_LIB_DIR='$(SWIG_LIB_DIR)' SWIGEXE='$(SWIGEXE)' \
-	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' JSENGINE='$(JSENGINE)' javascript_build_cpp
+	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' javascript_build_cpp
 
 clean:
 	$(MAKE) -f $(EXAMPLES_TOP)/Makefile SRCDIR='$(SRCDIR)' javascript_clean
diff --git a/Examples/test-suite/javascript/Makefile.in b/Examples/test-suite/javascript/Makefile.in
index a124a068f..b2acbd8f2 100644
--- a/Examples/test-suite/javascript/Makefile.in
+++ b/Examples/test-suite/javascript/Makefile.in
@@ -25,9 +25,22 @@ SWIGEXE   = $(top_builddir)/swig
 SWIG_LIB_DIR = $(top_srcdir)/Lib
 
 ifneq (, $(ENGINE))
-	JSENGINE=$(ENGINE)
+    JSENGINE=$(ENGINE)
 else
-	JSENGINE=node
+ifneq (, $(NODEJS))
+    JSENGINE=node
+else
+ifneq (, @JSCENABLED@)
+    JSENGINE=jsc
+else
+ifneq (, @JSV8ENABLED@)
+    JSENGINE=v8
+else
+    # Shouldn't happen, but avoid empty value if it does.
+    JSENGINE=node
+endif
+endif
+endif
 endif
 
 ifneq (, $(V8_VERSION))
@@ -47,9 +60,9 @@ _setup = \
 	  echo "$(ACTION)ing $(LANGUAGE) ($(JSENGINE)) testcase $*" ;     \
 	fi;
 
-ifeq (node,$(JSENGINE))
+SWIGOPT += -$(JSENGINE)
 
-  SWIGOPT += -node
+ifeq (node,$(JSENGINE))
 
   # shut up some warnings
 
@@ -105,8 +118,6 @@ ifeq (node,$(JSENGINE))
 
 else
 
-  SWIGOPT += -$(JSENGINE)
-
 	run_testcase = \
 		if [ -f $(srcdir)/$*$(SCRIPTSUFFIX) ]; then \
 		  $(RUNTOOL) $(top_builddir)/Tools/javascript/javascript -$(JSENGINE) $(srcdir)/$*$(SCRIPTSUFFIX); \