Merge pull request #58 from RalfJung/abort_on_panic

avoid abort_on_panic dependency

libffi-rs/Cargo.toml

@@ -12,7 +12,6 @@ edition = "2018"
 
 [dependencies]
 libffi-sys = { path = "../libffi-sys-rs", version = "^2.0"}
-abort_on_panic = "2.0.0"
 libc = "0.2.65"
 
 [features]

libffi-rs/src/high/mod.rs

@@ -68,8 +68,6 @@
 //!
 //! Invoking the closure a second time will panic.
 
-use abort_on_panic::abort_on_panic;
-
 pub use crate::middle::{ffi_abi_FFI_DEFAULT_ABI, FfiAbi};
 
 pub mod types;
@@ -78,6 +76,27 @@ pub use types::{CType, Type};
 pub mod call;
 pub use call::*;
 
+macro_rules! abort_on_panic {
+    ($msg:literal, $body:expr) => {{
+        // Aborts when dropped (which will only happen due to an unwinding panic).
+        struct Bomb;
+        impl Drop for Bomb {
+            fn drop(&mut self) {
+                // We do our best to ignore errors that occur during printing.
+                // If this panics anyway, that'll still just be a double-panic which leads to abort.
+                let _ = writeln!(std::io::stderr(), $msg);
+                std::process::abort();
+            }
+        }
+
+        let b = Bomb;
+        // If this panics, `b` will be dropped, triggering the bomb.
+        $body;
+        // Defuse the bomb.
+        std::mem::forget(b);
+    }};
+}
+
 macro_rules! define_closure_mod {
     (
         $module:ident $cif:ident $fnptr:ident