gergely/taskwarrior-2.x
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more unsafe notations

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This commit is contained in:
Dustin J. Mitchell
2022-01-28 02:11:13 +00:00
parent 1470bbf741
commit b3cbec1af3
4 changed files with 70 additions and 25 deletions
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43
lib/src/task.rs
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@@ -10,21 +10,31 @@ pub struct TCTask {
}
impl TCTask {
pub(crate) fn as_ptr(task: Task) -> *mut TCTask {
/// Borrow a TCTask from C as an argument.
///
/// # Safety
///
/// The pointer must not be NULL. It is the caller's responsibility to ensure that the
/// lifetime assigned to the reference and the lifetime of the TCTask itself do not outlive
/// the lifetime promised by C.
pub(crate) unsafe fn from_arg_ref<'a>(tcstring: *const TCTask) -> &'a Self {
debug_assert!(!tcstring.is_null());
&*tcstring
}
/// Convert this to a return value for handing off to C.
pub(crate) fn return_val(task: Task) -> *mut TCTask {
Box::into_raw(Box::new(TCTask { inner: task }))
}
}
/// Utility function to safely convert *const TCTask into &Task
fn task_ref(task: *const TCTask) -> &'static Task {
debug_assert!(!task.is_null());
unsafe { &(*task).inner }
}
/// Get a task's UUID.
#[no_mangle]
pub extern "C" fn tc_task_get_uuid<'a>(task: *const TCTask) -> TCUuid {
let task: &'a Task = task_ref(task);
// SAFETY:
// - task is not NULL (promised by caller)
// - task's lifetime exceeds this function (promised by caller)
let task: &'a Task = &unsafe { TCTask::from_arg_ref(task) }.inner;
let uuid = task.get_uuid();
uuid.into()
}
@@ -32,7 +42,10 @@ pub extern "C" fn tc_task_get_uuid<'a>(task: *const TCTask) -> TCUuid {
/// Get a task's status.
#[no_mangle]
pub extern "C" fn tc_task_get_status<'a>(task: *const TCTask) -> TCStatus {
let task: &'a Task = task_ref(task);
// SAFETY:
// - task is not NULL (promised by caller)
// - task's lifetime exceeds this function (promised by caller)
let task: &'a Task = &unsafe { TCTask::from_arg_ref(task) }.inner;
task.get_status().into()
}
@@ -45,7 +58,10 @@ pub extern "C" fn tc_task_get_status<'a>(task: *const TCTask) -> TCStatus {
/// contains embedded NUL characters).
#[no_mangle]
pub extern "C" fn tc_task_get_description<'a>(task: *const TCTask) -> *mut TCString<'static> {
let task = task_ref(task);
// SAFETY:
// - task is not NULL (promised by caller)
// - task's lifetime exceeds this function (promised by caller)
let task: &'a Task = &unsafe { TCTask::from_arg_ref(task) }.inner;
let descr: TCString = task.get_description().into();
descr.return_val()
}
@@ -64,9 +80,14 @@ pub extern "C" fn tc_task_get_description<'a>(task: *const TCTask) -> *mut TCStr
* get_modified
*/
/// Free a task.
/// Free a task. The given task must not be NULL. The task must not be used after this function
/// returns, and must not be freed more than once.
#[no_mangle]
pub extern "C" fn tc_task_free<'a>(task: *mut TCTask) {
debug_assert!(!task.is_null());
// SAFETY:
// - task is not NULL (promised by caller)
// - task's lifetime exceeds the drop (promised by caller)
// - task does not outlive this function (promised by caller)
drop(unsafe { Box::from_raw(task) });
}