diff -r 000000000000 -r 6474c204b198 xpcom/reflect/xptinfo/tests/TestInterfaceInfo.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/reflect/xptinfo/tests/TestInterfaceInfo.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,123 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Some simple smoke tests of the typelib loader. */
+
+#include "nscore.h"
+
+#include "nsISupports.h"
+#include "nsIInterfaceInfo.h"
+#include "nsIInterfaceInfoManager.h"
+#include "xptinfo.h"
+#include "nsServiceManagerUtils.h"
+
+#include <stdio.h>
+
+// This file expects the nsInterfaceInfoManager to be able to discover
+// .xpt files corresponding to those in xpcom/idl.  Currently this
+// means setting XPTDIR in the environment to some directory
+// containing these files.
+
+int main (int argc, char **argv) {
+    int i;
+    nsIID *iid1, *iid2, *iid3;
+    char *name1, *name2, *name3;
+    nsIInterfaceInfo *info2, *info3, *info4, *info5;
+
+    nsCOMPtr<nsIInterfaceInfoManager> iim
+        (do_GetService(NS_INTERFACEINFOMANAGER_SERVICE_CONTRACTID));
+
+    fprintf(stderr, "\ngetting iid for 'nsISupports'\n");
+    iim->GetIIDForName("nsISupports", &iid1);
+    iim->GetNameForIID(iid1, &name1);
+    fprintf(stderr, "%s iid %s\n", name1, iid1->ToString());
+
+    fprintf(stderr, "\ngetting iid for 'nsIInputStream'\n");
+    iim->GetIIDForName("nsIInputStream", &iid2);
+    iim->GetNameForIID(iid2, &name2);
+    fprintf(stderr, "%s iid %s\n", name2, iid2->ToString());
+
+    fprintf(stderr, "iid: %s, name: %s\n", iid1->ToString(), name1);
+    fprintf(stderr, "iid: %s, name: %s\n", iid2->ToString(), name2);
+
+    fprintf(stderr, "\ngetting info for iid2 from above\n");
+    iim->GetInfoForIID(iid2, &info2);
+#ifdef DEBUG
+//    ((nsInterfaceInfo *)info2)->print(stderr);
+#endif
+
+    fprintf(stderr, "\ngetting iid for 'nsIInputStream'\n");
+    iim->GetIIDForName("nsIInputStream", &iid3);
+    iim->GetNameForIID(iid3, &name3);
+    fprintf(stderr, "%s iid %s\n", name3, iid2->ToString());
+    iim->GetInfoForIID(iid3, &info3);
+#ifdef DEBUG
+//    ((nsInterfaceInfo *)info3)->print(stderr);
+#endif
+
+    fprintf(stderr, "\ngetting info for name 'nsIBidirectionalEnumerator'\n");
+    iim->GetInfoForName("nsIBidirectionalEnumerator", &info4);
+#ifdef DEBUG
+//    ((nsInterfaceInfo *)info4)->print(stderr);
+#endif
+
+    fprintf(stderr, "\nparams work?\n");
+    fprintf(stderr, "\ngetting info for name 'nsIServiceManager'\n");
+    iim->GetInfoForName("nsIComponentManager", &info5);
+#ifdef DEBUG
+//    ((nsInterfaceInfo *)info5)->print(stderr);
+#endif
+
+    // XXX: nsIServiceManager is no more; what do we test with?
+    if (info5 == nullptr) {
+        fprintf(stderr, "\nNo nsIComponentManager; cannot continue.\n");
+        return 1;
+    }
+
+    uint16_t methodcount;
+    info5->GetMethodCount(&methodcount);
+    const nsXPTMethodInfo *mi;
+    for (i = 0; i < methodcount; i++) {
+        info5->GetMethodInfo(i, &mi);
+        fprintf(stderr, "method %d, name %s\n", i, mi->GetName());
+    }
+
+    // 4 is getServiceByContractID, which has juicy params.
+    info5->GetMethodInfo(6, &mi);
+
+    const nsXPTParamInfo& param2 = mi->GetParam(1);
+    // should be IID for the service
+    nsIID *nsISL;
+    info5->GetIIDForParam(6, &param2, &nsISL);
+    fprintf(stderr, "iid assoc'd with param 1 of method 6 - createInstanceByContractID - %s\n", nsISL->ToString());
+    // if we look up the name?
+    char *nsISLname;
+    iim->GetNameForIID(nsISL, &nsISLname);
+    fprintf(stderr, "which is called %s\n", nsISLname);
+
+    fprintf(stderr, "\nNow check the last param\n");
+    const nsXPTParamInfo& param3 = mi->GetParam(3);
+
+    if (param3.GetType().TagPart() != nsXPTType::T_INTERFACE_IS) {
+        fprintf(stderr, "Param 3 is not type interface is\n");
+        // Not returning an error, because this could legitamately change
+    }
+    // lets see what arg this refers to
+    uint8_t argnum;
+    info5->GetInterfaceIsArgNumberForParam(6, &param3, &argnum);
+    fprintf(stderr, "param 3 referrs to param %d of method 6 - createInstanceByContractID\n", (uint32_t)argnum);
+    // Get the type of the parameter referred to
+    const nsXPTParamInfo& arg_param = mi->GetParam(argnum);
+    const nsXPTType& arg_type = arg_param.GetType();
+    // Check to make sure it refers to the proper param
+    if(!arg_type.IsPointer() || arg_type.TagPart() != nsXPTType::T_IID) {
+        fprintf(stderr, "Param 3 of method 6 refers to a non IID parameter\n"); 
+        // Not returning an error, because this could legitamately change
+    }
+
+
+    return 0;
+}    
+