kernel: Use try_set_value(_or_error) in various places

apps/sh.cpp

@@ -93,16 +93,14 @@ int main()
 
         if (child == 0)
         {
-            auto maybe_argv = split_command_into_argv(command);
+            Vector<char*> argv;
-            if (maybe_argv.has_error())
+            bool ok = split_command_into_argv(command).try_set_value_or_error(argv, errno);
+            if (!ok)
             {
-                errno = maybe_argv.error();
                 perror("failed to parse command");
                 return 1;
             }
 
-            auto argv = maybe_argv.release_value();
-
             if (argv[0] == NULL) return 0;
             sh_execvp(argv.data());
             perror(argv[0]);

kernel/src/memory/KernelVM.cpp

@@ -30,10 +30,9 @@ namespace KernelVM
     {
         auto kernelvm_bitmap = g_kernelvm_bitmap.lock();
 
-        const auto maybe_index = kernelvm_bitmap->find_and_toggle(false);
+        usize index;
-        if (!maybe_index.has_value()) return err(ENOMEM);
+        bool ok = kernelvm_bitmap->find_and_toggle(false).try_set_value(index);
-
+        if (!ok) return err(ENOMEM);
-        const usize index = maybe_index.value();
 
         g_used_vm += ARCH_PAGE_SIZE;
 

kernel/src/memory/MemoryManager.cpp

@@ -139,10 +139,9 @@ namespace MemoryManager
     {
         auto frame_bitmap = g_frame_bitmap.lock();
 
-        const auto maybe_index = frame_bitmap->find_and_toggle(false, start_index);
+        usize index;
-        if (!maybe_index.has_value()) return err(ENOMEM);
+        bool ok = frame_bitmap->find_and_toggle(false, start_index).try_set_value(index);
-
+        if (!ok) return err(ENOMEM);
-        const usize index = maybe_index.value();
 
         start_index = index + 1;
 

kernel/src/memory/UserVM.cpp

@@ -65,15 +65,13 @@ Result<bool> UserVM::try_expand(usize size)
 Result<u64> UserVM::alloc_one_page()
 {
     u64 index;
-    const auto maybe_index = m_bitmap.find_and_toggle(false);
+    bool ok = m_bitmap.find_and_toggle(false).try_set_value(index);
-    if (!maybe_index.has_value())
+    if (!ok)
     {
         bool success = TRY(try_expand());
         if (!success) return err(ENOMEM);
         index = TRY(Result<u64>::from_option(m_bitmap.find_and_toggle(false), ENOMEM));
     }
-    else
-        index = maybe_index.value();
 
     return VM_BASE + index * ARCH_PAGE_SIZE;
 }
@@ -81,15 +79,13 @@ Result<u64> UserVM::alloc_one_page()
 Result<u64> UserVM::alloc_several_pages(usize count)
 {
     u64 index;
-    const auto maybe_index = m_bitmap.find_and_toggle_region(false, count);
+    bool ok = m_bitmap.find_and_toggle_region(false, count).try_set_value(index);
-    if (!maybe_index.has_value())
+    if (!ok)
     {
         bool success = TRY(try_expand((count / 8) + INITIAL_VM_SIZE));
         if (!success) return err(ENOMEM);
         index = TRY(Result<u64>::from_option(m_bitmap.find_and_toggle_region(false, count), ENOMEM));
     }
-    else
-        index = maybe_index.value();
 
     return VM_BASE + index * ARCH_PAGE_SIZE;
 }

kernel/src/sys/getdents.cpp

@@ -19,13 +19,12 @@ Result<u64> sys_getdents(Registers*, SyscallArgs args)
     usize nwrite = 0;
     while (nwrite < count)
     {
-        auto maybe_entry = descriptor.inode->get(descriptor.offset);
+        VFS::DirectoryEntry entry;
-        if (!maybe_entry.has_value()) break;
+        bool ok = descriptor.inode->get(descriptor.offset).try_set_value(entry);
+        if (!ok) break;
 
         descriptor.offset++;
 
-        auto entry = maybe_entry.release_value();
-
         luna_dirent kent;
         kent.inode = entry.inode->inode_number();
         strlcpy(kent.name, entry.name.chars(), entry.name.length() + 1);

kernel/src/sys/open.cpp

@@ -24,27 +24,27 @@ Result<u64> sys_open(Registers*, SyscallArgs args)
     // Caller did not pass either O_RDONLY, O_WRONLY or O_RDWR
     if ((flags & O_RDWR) == 0) { return err(EINVAL); }
 
-    auto maybe_inode = VFS::resolve_path(path.chars());
+    int error;
-    if (maybe_inode.has_error())
+    bool ok = VFS::resolve_path(path.chars()).try_set_value_or_error(inode, error);
+    if (!ok)
     {
-        if (maybe_inode.error() == ENOENT && (flags & O_CREAT))
+        if (error == ENOENT && (flags & O_CREAT))
         {
             inode = TRY(VFS::create_file(path.chars()));
             inode->chmod(mode);
         }
         else
-            return maybe_inode.release_error();
+            return err(error);
     }
     else if (flags & O_EXCL)
         return err(EEXIST);
     else
     {
-        inode = maybe_inode.release_value();
         if ((flags & O_RDONLY) && (inode->mode() & S_IRUSR) == 0) return err(EACCES);
         if ((flags & O_WRONLY) && (inode->mode() & S_IWUSR) == 0) return err(EACCES);
     }
 
-    if(inode->type() != VFS::InodeType::Directory && (flags & O_DIRECTORY)) return err(ENOTDIR);
+    if (inode->type() != VFS::InodeType::Directory && (flags & O_DIRECTORY)) return err(ENOTDIR);
 
     if ((flags & O_WRONLY) && (flags & O_TRUNC)) inode->truncate(0);