on Windows, use miri_static_root for TLS dtors

2 files changed, 20 insertions, 2 deletions

diff --git a/src/librustc_mir/interpret/memory.rs b/src/librustc_mir/interpret/memory.rs
index 8af1a8ac608..ae837f8e165 100644
--- a/src/librustc_mir/interpret/memory.rs
+++ b/src/librustc_mir/interpret/memory.rs
@@ -716,7 +716,9 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
         }
     }
 
-    pub fn leak_report(&self) -> usize {
+    /// Print leaked memory. Allocations reachable from `static_roots` or a `Global` allocation
+    /// are not considered leaked. Leaks whose kind `may_leak()` returns true are not reported.
+    pub fn leak_report(&self, static_roots: &[AllocId]) -> usize {
         // Collect the set of allocations that are *reachable* from `Global` allocations.
         let reachable = {
             let mut reachable = FxHashSet::default();
@@ -724,6 +726,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
             let mut todo: Vec<_> = self.alloc_map.filter_map_collect(move |&id, &(kind, _)| {
                 if Some(kind) == global_kind { Some(id) } else { None }
             });
+            todo.extend(static_roots);
             while let Some(id) = todo.pop() {
                 if reachable.insert(id) {
                     // This is a new allocation, add its relocations to `todo`.
diff --git a/src/libstd/sys/windows/thread_local_key.rs b/src/libstd/sys/windows/thread_local_key.rs
index e0bb102b3af..0bd9600b6f2 100644
--- a/src/libstd/sys/windows/thread_local_key.rs
+++ b/src/libstd/sys/windows/thread_local_key.rs
@@ -110,6 +110,16 @@ struct Node {
     next: *mut Node,
 }
 
+#[cfg(miri)]
+extern "Rust" {
+    /// Miri-provided extern function to mark the block `ptr` points to as a "root"
+    /// for some static memory. This memory and everything reachable by it is not
+    /// considered leaking even if it still exists when the program terminates.
+    ///
+    /// `ptr` has to point to the beginning of an allocated block.
+    fn miri_static_root(ptr: *const u8);
+}
+
 unsafe fn register_dtor(key: Key, dtor: Dtor) {
     let mut node = Box::new(Node { key, dtor, next: ptr::null_mut() });
 
@@ -117,7 +127,12 @@ unsafe fn register_dtor(key: Key, dtor: Dtor) {
     loop {
         node.next = head;
         match DTORS.compare_exchange(head, &mut *node, SeqCst, SeqCst) {
-            Ok(_) => return mem::forget(node),
+            Ok(_) => {
+                #[cfg(miri)]
+                miri_static_root(&*node as *const _ as *const u8);
+
+                return mem::forget(node);
+            }
             Err(cur) => head = cur,
         }
     }