Enforce WARN_UNUSED_RESULT attribute on Windows

chrome/utility/importer/ie_importer_win.cc

Index: chrome/utility/importer/ie_importer_win.cc
diff --git a/chrome/utility/importer/ie_importer_win.cc b/chrome/utility/importer/ie_importer_win.cc
index 6bff0e43845d93df8075d573e2ea1321691effb3..1f7f2190e3b444b9f689c2d11ed04eebc45f8a02 100644
--- a/chrome/utility/importer/ie_importer_win.cc
+++ b/chrome/utility/importer/ie_importer_win.cc
@@ -160,11 +160,17 @@ struct IEOrderBookmarkComparator {
 //   };
 // where each item_id should correspond to a favorites link file (*.url) in
 // the current folder.
-bool ParseFavoritesOrderBlob(
-    const Importer* importer,
-    const std::vector<uint8>& blob,
-    const base::FilePath& path,
-    std::map<base::FilePath, uint32>* sort_index) WARN_UNUSED_RESULT {
+// GCC, in its infinite wisdom, does not allow WARN_UNUSED_RESULT to be used in

[Lei Zhang, 2015/10/07 16:28:09]

What is GCC doing touching a _win.cc file? Did you mean Clang? Can we fix Clang
if that's what you meant?

[dcheng, 2015/10/07 16:41:34]

GCC only allows function attributes on prototypes.
Therefore, clang emits a warning for GCC compatibility.
I'm honestly not sure what the best thing to say here is: I guess we could have
clang-cl implicitly disable -Wgcc-compat

[Lei Zhang, 2015/10/07 20:33:11]

Can you mention the clang / gcc compatibility issue? Otherwise it's confusing
for readers.

[dcheng, 2015/10/08 03:48:07]

Done.

+// a definition.
+bool ParseFavoritesOrderBlob(const Importer* importer,
+                             const std::vector<uint8>& blob,
+                             const base::FilePath& path,
+                             std::map<base::FilePath, uint32>* sort_index)
+    WARN_UNUSED_RESULT;
+bool ParseFavoritesOrderBlob(const Importer* importer,
+                             const std::vector<uint8>& blob,
+                             const base::FilePath& path,
+                             std::map<base::FilePath, uint32>* sort_index) {
   static const int kItemCountOffset = 16;
   static const int kItemListStartOffset = 20;
 
@@ -212,7 +218,12 @@ bool ParseFavoritesOrderRegistryTree(
     const Importer* importer,
     const base::win::RegKey& key,
     const base::FilePath& path,
-    std::map<base::FilePath, uint32>* sort_index) WARN_UNUSED_RESULT {
+    std::map<base::FilePath, uint32>* sort_index) WARN_UNUSED_RESULT;
+bool ParseFavoritesOrderRegistryTree(
+    const Importer* importer,
+    const base::win::RegKey& key,
+    const base::FilePath& path,
+    std::map<base::FilePath, uint32>* sort_index) {
   // Parse the order information of the current folder.
   DWORD blob_length = 0;
   if (key.ReadValue(L"Order", NULL, &blob_length, NULL) == ERROR_SUCCESS) {
@@ -241,9 +252,11 @@ bool ParseFavoritesOrderRegistryTree(
   return true;
 }
 
-bool ParseFavoritesOrderInfo(
-    const Importer* importer,
-    std::map<base::FilePath, uint32>* sort_index) WARN_UNUSED_RESULT {
+bool ParseFavoritesOrderInfo(const Importer* importer,
+                             std::map<base::FilePath, uint32>* sort_index)
+    WARN_UNUSED_RESULT;
+bool ParseFavoritesOrderInfo(const Importer* importer,
+                             std::map<base::FilePath, uint32>* sort_index) {
   base::string16 key_path(importer::GetIEFavoritesOrderKey());
   base::win::RegKey key(HKEY_CURRENT_USER, key_path.c_str(), KEY_READ);
   if (!key.Valid())