Avoid using unions for LongDirEntry.

GCC still assumes that the dirent has no data past the end for some
scenarios here and still mis-optimizes things. Therefore, drop the
usages of unions altogether, and instead use a casted character array.

Additionally, use B_FILE_NAME_LENGTH for the array, not B_PATH_NAME_LENGTH,
and make sure to add 1 for the NULL terminator.

headers/private/storage/storage_support.h

@@ -25,9 +25,9 @@ namespace BPrivate {
 namespace Storage {
 
 // For convenience:
-union LongDirEntry {
+struct LongDirEntry {
-	struct dirent dirent;
+	char _[sizeof(struct dirent) + B_FILE_NAME_LENGTH + 1];
-	char _[sizeof(struct dirent) + B_PATH_NAME_LENGTH];
+	struct dirent* dirent() { return (struct dirent*)_; }
 };
 
 //! Returns whether the supplied path is absolute.

src/build/libbe/storage/Directory.cpp

@@ -333,7 +333,7 @@ BDirectory::GetNextRef(entry_ref* ref)
 		return B_FILE_ERROR;
 
 	BPrivate::Storage::LongDirEntry longEntry;
-	struct dirent* entry = &longEntry.dirent;
+	struct dirent* entry = longEntry.dirent();
 	bool next = true;
 	while (next) {
 		if (GetNextDirents(entry, sizeof(longEntry), 1) != 1)
@@ -377,7 +377,7 @@ BDirectory::CountEntries()
 		return error;
 	int32 count = 0;
 	BPrivate::Storage::LongDirEntry longEntry;
-	struct dirent* entry = &longEntry.dirent;
+	struct dirent* entry = longEntry.dirent();
 	while (error == B_OK) {
 		if (GetNextDirents(entry, sizeof(longEntry), 1) != 1)
 			break;

src/build/libbe/storage/MergedDirectory.cpp

@@ -110,7 +110,7 @@ status_t
 BMergedDirectory::GetNextRef(entry_ref* ref)
 {
 	BPrivate::Storage::LongDirEntry longEntry;
-	struct dirent* dirEntry = &longEntry.dirent;
+	struct dirent* dirEntry = longEntry.dirent();
 	int32 result = GetNextDirents(dirEntry, sizeof(longEntry), 1);
 	if (result < 0)
 		return result;

src/build/libbe/storage/Node.cpp

@@ -310,7 +310,7 @@ BNode::GetNextAttrName(char* buffer)
 		return B_FILE_ERROR;
 
 	BPrivate::Storage::LongDirEntry longEntry;
-	struct dirent* entry = &longEntry.dirent;
+	struct dirent* entry = longEntry.dirent();
 	ssize_t result = _kern_read_dir(fAttrFd, entry, sizeof(longEntry), 1);
 	if (result < 0)
 		return result;

src/build/libroot/fs_attr_untyped.cpp

@@ -129,10 +129,10 @@ class AttributeDirectory;
 typedef map<DIR*, AttributeDirectory*> AttrDirMap;
 static AttrDirMap sAttributeDirectories;
 
-// LongDirent
+// LongDirEntry
-union LongDirent {
+struct LongDirEntry {
-	struct dirent dirent;
+	char _[sizeof(struct dirent) + B_FILE_NAME_LENGTH + 1];
-	char _[sizeof(struct dirent) + B_FILE_NAME_LENGTH];
+	struct dirent* dirent() { return (struct dirent*)_; }
 };
 
 // AttributeHeader
@@ -260,11 +260,11 @@ public:
 			}
 
 			// prepare the dirent
-			strcpy(fDirent.dirent.d_name, name);
+			strcpy(fDirent.dirent()->d_name, name);
-			fDirent.dirent.d_ino = 0;
+			fDirent.dirent()->d_ino = 0;
 // TODO: We need the node ID!
 
-			*_entry = &fDirent.dirent;
+			*_entry = fDirent.dirent();
 			return B_OK;
 		}
 
@@ -309,7 +309,7 @@ private:
 	int			fFileFD;
 	string		fPath;
 	DIR*		fFakeDir;
-	LongDirent	fDirent;
+	LongDirEntry fDirent;
 	char*		fListing;
 	int			fListingLength;
 	int			fListingIndex;

src/kits/storage/Directory.cpp

@@ -353,7 +353,7 @@ BDirectory::GetNextRef(entry_ref* ref)
 		return B_FILE_ERROR;
 
 	BPrivate::Storage::LongDirEntry longEntry;
-	struct dirent* entry = &longEntry.dirent;
+	struct dirent* entry = longEntry.dirent();
 	bool next = true;
 	while (next) {
 		if (GetNextDirents(entry, sizeof(longEntry), 1) != 1)
@@ -397,7 +397,7 @@ BDirectory::CountEntries()
 		return error;
 	int32 count = 0;
 	BPrivate::Storage::LongDirEntry longEntry;
-	struct dirent* entry = &longEntry.dirent;
+	struct dirent* entry = longEntry.dirent();
 	while (error == B_OK) {
 		if (GetNextDirents(entry, sizeof(longEntry), 1) != 1)
 			break;

src/kits/storage/MergedDirectory.cpp

@@ -112,7 +112,7 @@ status_t
 BMergedDirectory::GetNextRef(entry_ref* ref)
 {
 	BPrivate::Storage::LongDirEntry longEntry;
-	struct dirent* entry = &longEntry.dirent;
+	struct dirent* entry = longEntry.dirent();
 	int32 result = GetNextDirents(entry, sizeof(longEntry), 1);
 	if (result < 0)
 		return result;

src/kits/storage/Node.cpp

@@ -320,7 +320,7 @@ BNode::GetNextAttrName(char* buffer)
 		return B_FILE_ERROR;
 
 	BPrivate::Storage::LongDirEntry longEntry;
-	struct dirent* entry = &longEntry.dirent;
+	struct dirent* entry = longEntry.dirent();
 	ssize_t result = _kern_read_dir(fAttrFd, entry, sizeof(longEntry), 1);
 	if (result < 0)
 		return result;

src/kits/storage/Query.cpp

@@ -349,7 +349,7 @@ BQuery::GetNextRef(entry_ref* ref)
 		error = B_FILE_ERROR;
 	if (error == B_OK) {
 		BPrivate::Storage::LongDirEntry longEntry;
-		struct dirent* entry = &longEntry.dirent;
+		struct dirent* entry = longEntry.dirent();
 		bool next = true;
 		while (error == B_OK && next) {
 			if (GetNextDirents(entry, sizeof(longEntry), 1) != 1) {

src/kits/tracker/VirtualDirectoryEntryList.cpp

@@ -83,7 +83,7 @@ status_t
 VirtualDirectoryEntryList::GetNextRef(entry_ref* ref)
 {
 	BPrivate::Storage::LongDirEntry longEntry;
-	struct dirent* entry = &longEntry.dirent;
+	struct dirent* entry = longEntry.dirent();
 	int32 result = GetNextDirents(entry, sizeof(longEntry), 1);
 	if (result < 0)
 		return result;

src/kits/tracker/VirtualDirectoryPoseView.cpp

@@ -209,7 +209,7 @@ VirtualDirectoryPoseView::_EntryCreated(const BMessage* message)
 			return true;
 
 		BPrivate::Storage::LongDirEntry longEntry;
-		struct dirent* entry = &longEntry.dirent;
+		struct dirent* entry = longEntry.dirent();
 		while (directory.GetNextDirents(entry, sizeof(longEntry), 1) == 1) {
 			if (strcmp(entry->d_name, ".") != 0
 				&& strcmp(entry->d_name, "..") != 0) {

src/system/boot/loader/vfs.cpp

@@ -42,10 +42,9 @@ using namespace boot;
 struct __DIR {
 	Directory*	directory;
 	void*		cookie;
-	union {
+
-		dirent		entry;
+	char		_direntBuffer[sizeof(dirent) + B_FILE_NAME_LENGTH + 1];
-		char		nameBuffer[sizeof(dirent) + B_FILE_NAME_LENGTH - 1];
+	dirent*		entry() { return (dirent*)_direntBuffer; }
-	};
 };
 
 
@@ -1260,33 +1259,33 @@ readdir(DIR* dir)
 
 	for (;;) {
 		status_t error = dir->directory->GetNextEntry(dir->cookie,
-			dir->entry.d_name, B_FILE_NAME_LENGTH);
+			dir->entry()->d_name, B_FILE_NAME_LENGTH);
 		if (error != B_OK) {
 			errno = error;
 			return NULL;
 		}
 
-		dir->entry.d_pdev = 0;
+		dir->entry()->d_pdev = 0;
 			// not supported
-		dir->entry.d_pino = dir->directory->Inode();
+		dir->entry()->d_pino = dir->directory->Inode();
-		dir->entry.d_dev = dir->entry.d_pdev;
+		dir->entry()->d_dev = dir->entry()->d_pdev;
 			// not supported
 
-		if (strcmp(dir->entry.d_name, ".") == 0
+		if (strcmp(dir->entry()->d_name, ".") == 0
-				|| strcmp(dir->entry.d_name, "..") == 0) {
+				|| strcmp(dir->entry()->d_name, "..") == 0) {
 			// Note: That's obviously not correct for "..", but we can't
 			// retrieve that information.
-			dir->entry.d_ino = dir->entry.d_pino;
+			dir->entry()->d_ino = dir->entry()->d_pino;
 		} else {
-			Node* node = dir->directory->Lookup(dir->entry.d_name, false);
+			Node* node = dir->directory->Lookup(dir->entry()->d_name, false);
 			if (node == NULL)
 				continue;
 
-			dir->entry.d_ino = node->Inode();
+			dir->entry()->d_ino = node->Inode();
 			node->Release();
 		}
 
-		return &dir->entry;
+		return dir->entry();
 	}
 }