build: Pull pacrunner forward to mozjs38

Mozjs185 is getting really old and unsupported. Newer versions
of the mozjs JSAPI are C++ based. So we convert the plugin to
C++ and then apply necessarily API changes so that it can be built
with the more recent mozjs38. For example we now need to "root"
values being passed into the API in order to satisfy the JSAPI
garbage collection rules. Further, a number of the APIs have been
tweaked and moved into the JS namespace, so we namespace them
appropriately and adjust their parameters.

3 files changed, 68 insertions, 60 deletions

diff --git a/Makefile.am b/Makefile.am
index ee84b75..65cc8c9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -31,9 +31,10 @@ endif
 if MOZJS
 js_sources = src/js_funcs.c
 builtin_modules += mozjs
-builtin_sources += plugins/mozjs.c
-builtin_cflags += @MOZJS_CFLAGS@
-builtin_libadd += @MOZJS_LIBS@
+builtin_libadd += plugins/libmozjsplugin.a @MOZJS_LIBS@ -lstdc++
+noinst_LIBRARIES += plugins/libmozjsplugin.a
+plugins_libmozjsplugin_a_SOURCES = plugins/mozjs.cc
+plugins_libmozjsplugin_a_CXXFLAGS = $(AM_CFLAGS) @MOZJS_CFLAGS@ @DBUS_CFLAGS@ @GLIB_CFLAGS@
 endif
 
 if V8
@@ -137,16 +138,16 @@ unit_test_pacrunner_LDADD += @CURL_LIBS@
 endif
 
 if MOZJS
-unit_test_pacrunner_SOURCES += plugins/mozjs.c
-
+unit_test_pacrunner_SOURCES += plugins/mozjs.cc
+unit_test_pacrunner_CXXFLAGS = $(AM_CFLAGS)  @MOZJS_CFLAGS@
 unit_test_pacrunner_LDADD += @MOZJS_LIBS@ @PTHREAD_LIBS@
 
 noinst_PROGRAMS += unit/test-mozjs
 
 unit_test_mozjs_SOURCES = unit/test-mozjs.c src/pacrunner.h \
 			src/proxy.c src/manual.c src/download.c \
-				src/js.c plugins/mozjs.c $(js_sources)
-
+				src/js.c plugins/mozjs.cc $(js_sources)
+unit_test_mozjs_CXXFLAGS = $(AM_CFLAGS)  @MOZJS_CFLAGS@
 unit_test_mozjs_LDADD = @MOZJS_LIBS@ @GLIB_LIBS@ @PTHREAD_LIBS@
 endif
 
diff --git a/configure.ac b/configure.ac
index 888c873..bf76fbb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -76,8 +76,8 @@ AM_CONDITIONAL(DUKTAPE, test "${enable_duktape}" = "yes")
 AC_ARG_ENABLE(mozjs, AC_HELP_STRING([--enable-mozjs],
 		[enable Mozilla Javascript plugin support]))
 if (test "${enable_mozjs}" = "yes"); then
-	PKG_CHECK_MODULES(MOZJS,  mozjs185, dummy=yes,
-			AC_MSG_ERROR(Mozilla Javascript >= 1.8 is required))
+	PKG_CHECK_MODULES(MOZJS,  mozjs-38, dummy=yes,
+			AC_MSG_ERROR(Mozilla Javascript version 38 is required))
 	AC_SUBST(MOZJS_CFLAGS)
 	AC_SUBST(MOZJS_LIBS)
 fi
diff --git a/plugins/mozjs.c b/plugins/mozjs.cc
index a923203..e10b297 100644
--- a/plugins/mozjs.c
+++ b/plugins/mozjs.cc
@@ -31,11 +31,15 @@
 #include <netdb.h>
 
 #pragma GCC diagnostic ignored "-Wredundant-decls"
+#pragma GCC diagnostic ignored "-Winvalid-offsetof"
 #include <jsapi.h>
 #pragma GCC diagnostic error "-Wredundant-decls"
+#pragma GCC diagnostic error "-Winvalid-offsetof"
 
+extern "C" {
 #include "pacrunner.h"
 #include "js.h"
+}
 
 static pthread_mutex_t mozjs_mutex = PTHREAD_MUTEX_INITIALIZER;
 
@@ -43,42 +47,42 @@ struct pacrunner_mozjs {
 	struct pacrunner_proxy *proxy;
 	JSContext *jsctx;
 	JSObject *jsobj;
+	JSAutoCompartment *jsac;
 };
 
-static JSBool myipaddress(JSContext *jsctx, uintN argc, jsval *vp)
+static bool myipaddress(JSContext *jsctx, unsigned argc, jsval *vp)
 {
-	struct pacrunner_mozjs *ctx = JS_GetContextPrivate(jsctx);
+	struct pacrunner_mozjs *ctx = (pacrunner_mozjs *)JS_GetContextPrivate(jsctx);
 	char address[NI_MAXHOST];
 
 	DBG("");
 
-	JS_SET_RVAL(jsctx, vp, JSVAL_NULL);
+	JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
+
+	args.rval().setNull();
 
 	if (!ctx)
-		return JS_TRUE;
+		return true;
 
 	if (__pacrunner_js_getipaddr(ctx->proxy, address, sizeof(address)) < 0)
-		return JS_TRUE;
+		return true;
 
 	DBG("address %s", address);
 
-	JS_SET_RVAL(jsctx, vp, STRING_TO_JSVAL(JS_NewStringCopyZ(jsctx,
-							       address)));
+	args.rval().setString(JS_NewStringCopyZ(jsctx,address));
 
-	return JS_TRUE;
+	return true;
 }
 
-static JSBool dnsresolve(JSContext *jsctx, uintN argc, jsval *vp)
+static bool dnsresolve(JSContext *jsctx, unsigned argc, jsval *vp)
 {
-	struct pacrunner_mozjs *ctx = JS_GetContextPrivate(jsctx);
+	struct pacrunner_mozjs *ctx = (pacrunner_mozjs *)JS_GetContextPrivate(jsctx);
 	char address[NI_MAXHOST];
-	jsval *argv = JS_ARGV(jsctx, vp);
-	char *host = JS_EncodeString(jsctx, JS_ValueToString(jsctx, argv[0]));
+	JS::CallArgs args = JS::CallArgsFromVp(argc,vp);
+	char * host = JS_EncodeString(jsctx, args[0].toString());
 
 	DBG("host %s", host);
 
-	JS_SET_RVAL(jsctx, vp, JSVAL_NULL);
-
 	if (!ctx)
 		goto out;
 
@@ -87,20 +91,16 @@ static JSBool dnsresolve(JSContext *jsctx, uintN argc, jsval *vp)
 
 	DBG("address %s", address);
 
-	JS_SET_RVAL(jsctx, vp, STRING_TO_JSVAL(JS_NewStringCopyZ(jsctx, address)));
+	args.rval().setString(JS_NewStringCopyZ(jsctx,address));
 
  out:
 	JS_free(jsctx, host);
-	return JS_TRUE;
+	return true;
 
 }
 
 static JSClass jscls = {
 	"global", JSCLASS_GLOBAL_FLAGS,
-	JS_PropertyStub, JS_PropertyStub, JS_PropertyStub,
-	JS_StrictPropertyStub,
-	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub,
-	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
 };
 
 static JSRuntime *jsrun;
@@ -109,13 +109,12 @@ static int create_object(struct pacrunner_proxy *proxy)
 {
 	struct pacrunner_mozjs *ctx;
 	const char *script;
-	jsval rval;
 
 	script = pacrunner_proxy_get_script(proxy);
 	if (!script)
 		return 0;
 
-	ctx = g_malloc0(sizeof(struct pacrunner_mozjs));
+	ctx = (pacrunner_mozjs *)g_malloc0(sizeof(struct pacrunner_mozjs));
 
 	ctx->proxy = proxy;
 	ctx->jsctx = JS_NewContext(jsrun, 8 * 1024);
@@ -126,41 +125,48 @@ static int create_object(struct pacrunner_proxy *proxy)
 	JS_SetContextPrivate(ctx->jsctx, ctx);
 	__pacrunner_proxy_set_jsctx(proxy, ctx);
 
-#if JS_VERSION >= 185
-	ctx->jsobj = JS_NewCompartmentAndGlobalObject(ctx->jsctx, &jscls,
-						      NULL);
-#else
-	ctx->jsobj = JS_NewObject(ctx->jsctx, &jscls, NULL, NULL);
-#endif
+	JS::CompartmentOptions compart_opts;
+	compart_opts.setVersion(JSVERSION_LATEST);
+	ctx->jsobj = JS_NewGlobalObject(ctx->jsctx, &jscls, nullptr,
+					JS::DontFireOnNewGlobalHook, compart_opts);
+	JS::RootedObject jsobj(ctx->jsctx,ctx->jsobj);
+
+	ctx->jsac = new JSAutoCompartment(ctx->jsctx, jsobj);
 
-	if (!JS_InitStandardClasses(ctx->jsctx, ctx->jsobj))
+	if (!JS_InitStandardClasses(ctx->jsctx, jsobj))
 		pacrunner_error("Failed to init JS standard classes");
 
-	JS_DefineFunction(ctx->jsctx, ctx->jsobj, "myIpAddress",
-			  myipaddress, 0, 0);
-	JS_DefineFunction(ctx->jsctx, ctx->jsobj,
-			  "dnsResolve", dnsresolve, 1, 0);
+	JS_DefineFunction(ctx->jsctx, jsobj, "myIpAddress", myipaddress, 0, 0);
+	JS_DefineFunction(ctx->jsctx, jsobj, "dnsResolve", dnsresolve, 1, 0);
+
+	JS::RootedValue rval(ctx->jsctx);
+	JS::CompileOptions opts(ctx->jsctx);
+	opts.setIntroductionType("pacrunner")
+	    .setUTF8(true)
+	    .setCompileAndGo(true);
 
-	JS_EvaluateScript(ctx->jsctx, ctx->jsobj, __pacrunner_js_routines,
-			  strlen(__pacrunner_js_routines), NULL, 0, &rval);
+	JS::Evaluate(ctx->jsctx, JS::HandleObject(jsobj), opts,
+		     __pacrunner_js_routines, strlen(__pacrunner_js_routines)
+		     , &rval);
 
-	JS_EvaluateScript(ctx->jsctx, ctx->jsobj, script, strlen(script),
-			  "wpad.dat", 0, &rval);
+	JS::Evaluate(ctx->jsctx, jsobj, opts, script, strlen(script), &rval);
 
 	return 0;
 }
 
 static int mozjs_clear_proxy(struct pacrunner_proxy *proxy)
 {
-	struct pacrunner_mozjs *ctx = __pacrunner_proxy_get_jsctx(proxy);
+	struct pacrunner_mozjs *ctx = (pacrunner_mozjs *)__pacrunner_proxy_get_jsctx(proxy);
 
 	DBG("proxy %p ctx %p", proxy, ctx);
 
 	if (!ctx)
 		return -EINVAL;
 
+	delete ctx->jsac;
 	JS_DestroyContext(ctx->jsctx);
 	__pacrunner_proxy_set_jsctx(proxy, NULL);
+	g_free(ctx);
 
 	return 0;
 }
@@ -168,7 +174,6 @@ static int mozjs_clear_proxy(struct pacrunner_proxy *proxy)
 static int mozjs_set_proxy(struct pacrunner_proxy *proxy)
 {
 	DBG("proxy %p", proxy);
-
 	if (!proxy)
 		return 0;
 
@@ -180,11 +185,9 @@ static int mozjs_set_proxy(struct pacrunner_proxy *proxy)
 static char * mozjs_execute(struct pacrunner_proxy *proxy, const char *url,
 			    const char *host)
 {
-	struct pacrunner_mozjs *ctx = __pacrunner_proxy_get_jsctx(proxy);
-	JSBool result;
-	jsval rval, args[2];
+	struct pacrunner_mozjs *ctx = (pacrunner_mozjs *)__pacrunner_proxy_get_jsctx(proxy);
+	bool result;
 	char *answer, *g_answer;
-
 	DBG("proxy %p ctx %p url %s host %s", proxy, ctx, url, host);
 
 	if (!ctx)
@@ -193,12 +196,16 @@ static char * mozjs_execute(struct pacrunner_proxy *proxy, const char *url,
 	pthread_mutex_lock(&mozjs_mutex);
 
 	JS_BeginRequest(ctx->jsctx);
+	JS::RootedValue rval(ctx->jsctx);
+	JS::AutoValueArray<2> args(ctx->jsctx);
+
+	args[0].setString(JS_NewStringCopyZ(ctx->jsctx, url));
+	args[1].setString(JS_NewStringCopyZ(ctx->jsctx, host));
 
-	args[0] = STRING_TO_JSVAL(JS_NewStringCopyZ(ctx->jsctx, url));
-	args[1] = STRING_TO_JSVAL(JS_NewStringCopyZ(ctx->jsctx, host));
 
-	result = JS_CallFunctionName(ctx->jsctx, ctx->jsobj,
-				     "FindProxyForURL", 2, args, &rval);
+	JS::RootedObject jsobj(ctx->jsctx,ctx->jsobj);
+
+	result = JS_CallFunctionName(ctx->jsctx, jsobj, "FindProxyForURL", args , &rval);
 
 	JS_EndRequest(ctx->jsctx);
 
@@ -207,8 +214,7 @@ static char * mozjs_execute(struct pacrunner_proxy *proxy, const char *url,
 	pthread_mutex_unlock(&mozjs_mutex);
 
 	if (result) {
-		answer = JS_EncodeString(ctx->jsctx,
-					 JS_ValueToString(ctx->jsctx, rval));
+		answer = JS_EncodeString(ctx->jsctx, rval.toString());
 		g_answer = g_strdup(answer);
 		JS_free(ctx->jsctx, answer);
 		return g_answer;
@@ -228,8 +234,8 @@ static struct pacrunner_js_driver mozjs_driver = {
 static int mozjs_init(void)
 {
 	DBG("");
-
-	jsrun = JS_NewRuntime(8 * 1024 * 1024);
+	JS_Init();
+	jsrun = JS_NewRuntime(JS::DefaultHeapMaxBytes, 8 * 1024 * 1024 );
 
 	return pacrunner_js_driver_register(&mozjs_driver);
 }
@@ -241,6 +247,7 @@ static void mozjs_exit(void)
 	pacrunner_js_driver_unregister(&mozjs_driver);
 
 	JS_DestroyRuntime(jsrun);
+	JS_ShutDown();
 }
 
 PACRUNNER_PLUGIN_DEFINE(mozjs, mozjs_init, mozjs_exit)