From 46164fd07624e11cd0e2afb31901643b8c84493f Mon Sep 17 00:00:00 2001
From: Oliver Scherer <github35764891676564198441@oli-obk.de>
Date: Fri, 16 Nov 2018 10:32:32 +0100
Subject: [PATCH] Support panics across stack growth boundaries

---
 src/lib.rs              |  7 +++++--
 tests/panic_handling.rs | 27 +++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)
 create mode 100644 tests/panic_handling.rs

diff --git a/src/lib.rs b/src/lib.rs
index 9420627..833fc8e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -86,10 +86,13 @@ fn grow_the_stack<R, F: FnOnce() -> R>(stack_size: usize, f: F) -> R {
     let mut ret = None;
     unsafe {
         _grow_the_stack(stack_size, &mut || {
-            ret = Some(f.take().unwrap()());
+            ret = Some(std::panic::catch_unwind(std::panic::AssertUnwindSafe(f.take().unwrap())));
         });
     }
-    ret.unwrap()
+    match ret.unwrap() {
+        Ok(ret) => ret,
+        Err(payload) => std::panic::resume_unwind(payload),
+    }
 }
 
 unsafe fn _grow_the_stack(stack_size: usize, mut f: &mut FnMut()) {
diff --git a/tests/panic_handling.rs b/tests/panic_handling.rs
new file mode 100644
index 0000000..045fa28
--- /dev/null
+++ b/tests/panic_handling.rs
@@ -0,0 +1,27 @@
+extern crate stacker;
+
+const RED_ZONE: usize = 100*1024; // 100k
+const STACK_PER_RECURSION: usize = 1 * 1024 * 1024; // 1MB
+
+pub fn ensure_sufficient_stack<R, F: FnOnce() -> R + std::panic::UnwindSafe>(
+    f: F
+) -> R {
+    stacker::maybe_grow(RED_ZONE, STACK_PER_RECURSION, f)
+}
+
+#[inline(never)]
+fn recurse(n: usize) {
+    let x = [42u8; 50000];
+    if n == 0 {
+        panic!("an inconvenient time");
+    } else {
+        ensure_sufficient_stack(|| recurse(n - 1));
+    }
+    drop(x);
+}
+
+#[test]
+#[should_panic]
+fn foo() {
+    recurse(10000);
+}
\ No newline at end of file