Bug 1811934 - Have nsID::ToString() return an managed string instead of a raw pointer r=xpcom-reviewers,nika

And use nsID::ToProvidedString(...) method when suitable.

This naturally fixes a memory leak in dom/fetch/FetchParent.cpp.

Differential Revision: https://phabricator.services.mozilla.com/D167606

dom/fetch/FetchParent.cpp

@@ -27,7 +27,7 @@ FetchParent::FetchParentCSPEventListener::FetchParentCSPEventListener(
     : mActorID(aActorID), mEventTarget(aEventTarget) {
   MOZ_ASSERT(mEventTarget);
   FETCH_LOG(("FetchParentCSPEventListener [%p] actor ID: %s", this,
-             mActorID.ToString()));
+             mActorID.ToString().get()));
 }
 
 NS_IMETHODIMP FetchParent::FetchParentCSPEventListener::OnCSPViolationEvent(

js/xpconnect/src/XPCWrappedJS.cpp

@@ -594,8 +594,7 @@ nsXPCWrappedJS* nsXPCWrappedJS::FindInherited(REFNSIID aIID) {
   return nullptr;
 }
 
-nsresult
-nsIXPConnectWrappedJS::GetInterfaceIID(nsIID** iid) {
+nsresult nsIXPConnectWrappedJS::GetInterfaceIID(nsIID** iid) {
   MOZ_ASSERT(iid, "bad param");
 
   *iid = AsXPCWrappedJS()->GetIID().Clone();
@@ -662,11 +661,8 @@ nsresult nsXPCWrappedJS::DebugDump(int16_t depth) {
                   IsRootWrapper() ? "ROOT" : "non-root", mJSObj.get()));
   const char* name = mInfo->Name();
   XPC_LOG_ALWAYS(("interface name is %s", name));
-  char* iid = mInfo->IID().ToString();
-  XPC_LOG_ALWAYS(("IID number is %s", iid ? iid : "invalid"));
-  if (iid) {
-    free(iid);
-  }
+  auto iid = mInfo->IID().ToString();
+  XPC_LOG_ALWAYS(("IID number is %s", iid.get()));
   XPC_LOG_ALWAYS(("nsXPTInterfaceInfo @ %p", mInfo));
 
   if (!IsRootWrapper()) {

js/xpconnect/src/XPCWrappedJSClass.cpp

@@ -1065,11 +1065,8 @@ void nsXPCWrappedJS::DebugDumpInterfaceInfo(const nsXPTInterfaceInfo* aInfo,
   XPC_LOG_INDENT();
   const char* name = aInfo->Name();
   XPC_LOG_ALWAYS(("interface name is %s", name));
-  char* iid = aInfo->IID().ToString();
-  XPC_LOG_ALWAYS(("IID number is %s", iid ? iid : "invalid"));
-  if (iid) {
-    free(iid);
-  }
+  auto iid = aInfo->IID().ToString();
+  XPC_LOG_ALWAYS(("IID number is %s", iid.get()));
   XPC_LOG_ALWAYS(("InterfaceInfo @ %p", aInfo));
   uint16_t methodCount = 0;
   if (depth) {

toolkit/components/extensions/webidl-api/ExtensionAPIRequest.cpp

@@ -39,7 +39,7 @@ ExtensionServiceWorkerInfo::GetScriptURL(nsAString& aScriptURL) {
 NS_IMETHODIMP
 ExtensionServiceWorkerInfo::GetClientInfoId(nsAString& aClientInfoId) {
   MOZ_ASSERT(NS_IsMainThread());
-  aClientInfoId = NS_ConvertUTF8toUTF16(mClientInfo.Id().ToString());
+  aClientInfoId = NS_ConvertUTF8toUTF16(mClientInfo.Id().ToString().get());
   return NS_OK;
 }
 

xpcom/base/nsID.cpp

@@ -163,18 +163,10 @@ static const char gIDFormat[] =
     "{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}";
 
 /*
- * Returns an allocated string in {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
- * format. The string is allocated with moz_xmalloc and should be freed by
- * the caller.
+ * Returns a managed string in {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
+ * format.
  */
-
-char* nsID::ToString() const {
-  char* res = (char*)moz_xmalloc(NSID_LENGTH);
-  snprintf(res, NSID_LENGTH, gIDFormat, m0, (uint32_t)m1, (uint32_t)m2,
-           (uint32_t)m3[0], (uint32_t)m3[1], (uint32_t)m3[2], (uint32_t)m3[3],
-           (uint32_t)m3[4], (uint32_t)m3[5], (uint32_t)m3[6], (uint32_t)m3[7]);
-  return res;
-}
+nsIDToCString nsID::ToString() const { return nsIDToCString(*this); }
 
 void nsID::ToProvidedString(char (&aDest)[NSID_LENGTH]) const {
   SprintfLiteral(aDest, gIDFormat, m0, (uint32_t)m1, (uint32_t)m2,

xpcom/base/nsID.h

@@ -13,6 +13,10 @@
 
 #define NSID_LENGTH 39
 
+#ifndef XPCOM_GLUE_AVOID_NSPR
+class nsIDToCString;
+#endif
+
 /**
  * A "unique identifier". This is modeled after OSF DCE UUIDs.
  */
@@ -69,11 +73,10 @@ struct nsID {
 
 #ifndef XPCOM_GLUE_AVOID_NSPR
   /**
-   * nsID string encoder. Returns an allocated string in
-   * {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} format. Caller should free string.
-   * YOU SHOULD ONLY USE THIS IF YOU CANNOT USE ToProvidedString() BELOW.
+   * nsID string encoder. Returns a managed string in
+   * {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} format.
    */
-  char* ToString() const;
+  nsIDToCString ToString() const;
 
   /**
    * nsID string encoder. Builds a string in

xpcom/components/nsComponentManager.cpp

@@ -657,11 +657,9 @@ nsComponentManagerImpl::GetClassObject(const nsCID& aClass, const nsIID& aIID,
   nsresult rv;
 
   if (MOZ_LOG_TEST(nsComponentManagerLog, LogLevel::Debug)) {
-    char* buf = aClass.ToString();
+    char buf[NSID_LENGTH];
+    aClass.ToProvidedString(buf);
     PR_LogPrint("nsComponentManager: GetClassObject(%s)", buf);
-    if (buf) {
-      free(buf);
-    }
   }
 
   MOZ_ASSERT(aResult != nullptr);
@@ -765,13 +763,11 @@ nsComponentManagerImpl::CreateInstance(const nsCID& aClass, const nsIID& aIID,
   }
 
   if (MOZ_LOG_TEST(nsComponentManagerLog, LogLevel::Warning)) {
-    char* buf = aClass.ToString();
+    char buf[NSID_LENGTH];
+    aClass.ToProvidedString(buf);
     MOZ_LOG(nsComponentManagerLog, LogLevel::Warning,
             ("nsComponentManager: CreateInstance(%s) %s", buf,
              NS_SUCCEEDED(rv) ? "succeeded" : "FAILED"));
-    if (buf) {
-      free(buf);
-    }
   }
 
   return rv;

xpcom/ds/nsVariant.cpp

@@ -703,12 +703,7 @@ nsresult nsDiscriminatedUnion::ToString(nsACString& aOutString) const {
       // nsID has its own text formatter.
 
     case nsIDataType::VTYPE_ID: {
-      char* ptr = u.mIDValue.ToString();
-      if (!ptr) {
-        return NS_ERROR_OUT_OF_MEMORY;
-      }
-      aOutString.Assign(ptr);
-      free(ptr);
+      aOutString.Assign(u.mIDValue.ToString().get());
       return NS_OK;
     }
 

xpcom/tests/gtest/TestID.cpp

@@ -27,10 +27,7 @@ TEST(nsID, StringConversion)
     const char* idstr = ids[i];
     ASSERT_TRUE(id.Parse(idstr));
 
-    char* cp = id.ToString();
-    ASSERT_NE(cp, nullptr);
-    ASSERT_STREQ(cp, ids[4 * (i / 4) + 3]);
-
-    free(cp);
+    auto cp = id.ToString();
+    ASSERT_STREQ(cp.get(), ids[4 * (i / 4) + 3]);
   }
 }