Mark all extern functions as nounwind

Unwinding across an FFI boundary is undefined behaviour, so we can mark
all external function as nounwind. The obvious exception are those
functions that actually perform the unwinding.

diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 78a467e365799125b2d5c3dde848bd61d2d133af..94408072932ea5d6a5ad1690602d1331b8eaaba9 100644 (file)
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -79,6 +79,7 @@
 #![feature(optin_builtin_traits)]
 #![feature(reflect)]
 #![feature(rustc_attrs)]
+#![feature(unwind_attributes)]
 #![cfg_attr(stage0, feature(simd))]
 #![cfg_attr(not(stage0), feature(repr_simd, platform_intrinsics))]
 #![feature(staged_api)]

diff --git a/src/libcore/panicking.rs b/src/libcore/panicking.rs
index b443ae0636faa979a9319b1636f4800098ff3feb..93ddfa72f63ca78f65413726246f5a2a538365e4 100644 (file)
--- a/src/libcore/panicking.rs
+++ b/src/libcore/panicking.rs
@@ -62,6 +62,7 @@ pub fn panic_fmt(fmt: fmt::Arguments, file_line: &(&'static str, u32)) -> ! {
     #[allow(improper_ctypes)]
     extern {
         #[lang = "panic_fmt"]
+        #[unwind]
         fn panic_impl(fmt: fmt::Arguments, file: &'static str, line: u32) -> !;
     }
     let (file, line) = *file_line;

diff --git a/src/librustc_trans/trans/foreign.rs b/src/librustc_trans/trans/foreign.rs
index 9a561249594929d0c9d96149c0abc427b22e0a3c..cbb092aa4eb33b3ada7e399e4a1e2b3faaf451d9 100644 (file)
--- a/src/librustc_trans/trans/foreign.rs
+++ b/src/librustc_trans/trans/foreign.rs
@@ -211,6 +211,7 @@ pub fn register_foreign_item_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
     let llfn_ty = lltype_for_fn_from_foreign_types(ccx, &tys);
 
     let llfn = get_extern_fn(ccx, &mut *ccx.externs().borrow_mut(), name, cc, llfn_ty, fty);
+    attributes::unwind(llfn, false);
     add_argument_attributes(&tys, llfn);
     attributes::from_fn_attrs(ccx, attrs, llfn);
     llfn

diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index fca4c66112eb6c89e3ad878ef0f442abbb6cf1e2..dc370d8382a4d4ada3b378bcf2f498d5786e15c4 100644 (file)
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -243,6 +243,7 @@
 #![feature(unique)]
 #![feature(unsafe_no_drop_flag, filling_drop)]
 #![feature(decode_utf16)]
+#![feature(unwind_attributes)]
 #![feature(vec_push_all)]
 #![feature(vec_resize)]
 #![feature(wrapping)]

diff --git a/src/libstd/sys/common/libunwind.rs b/src/libstd/sys/common/libunwind.rs
index fde612014e9921f3b3f32b807d172b76894ca12d..c6bffb0f733eeab4223110db1017b4cd39f51921 100644 (file)
--- a/src/libstd/sys/common/libunwind.rs
+++ b/src/libstd/sys/common/libunwind.rs
@@ -124,10 +124,12 @@ pub enum _Unwind_Context {}
     // iOS on armv7 uses SjLj exceptions and requires to link
     // against corresponding routine (..._SjLj_...)
     #[cfg(not(all(target_os = "ios", target_arch = "arm")))]
+    #[unwind]
     pub fn _Unwind_RaiseException(exception: *mut _Unwind_Exception)
                                   -> _Unwind_Reason_Code;
 
     #[cfg(all(target_os = "ios", target_arch = "arm"))]
+    #[unwind]
     fn _Unwind_SjLj_RaiseException(e: *mut _Unwind_Exception)
                                    -> _Unwind_Reason_Code;
 

diff --git a/src/libstd/sys/common/unwind/mod.rs b/src/libstd/sys/common/unwind/mod.rs
index ff93d0526b7efaea749dfbd756adf3f69d7c8ab8..738681c3cfed7469023d2e39cb74d44743c57ab4 100644 (file)
--- a/src/libstd/sys/common/unwind/mod.rs
+++ b/src/libstd/sys/common/unwind/mod.rs
@@ -192,6 +192,7 @@ fn rust_panic(cause: Box<Any + Send + 'static>) -> ! {
 #[cfg(not(test))]
 /// Entry point of panic from the libcore crate.
 #[lang = "panic_fmt"]
+#[unwind]
 pub extern fn rust_begin_unwind(msg: fmt::Arguments,
                                 file: &'static str, line: u32) -> ! {
     begin_unwind_fmt(msg, &(file, line))

diff --git a/src/libstd/sys/common/unwind/seh.rs b/src/libstd/sys/common/unwind/seh.rs
index a201e406a23ead19324a66bf5a6c6221a6035080..a89e8b499acceae3d84c1fa2c8853621d26d775c 100644 (file)
--- a/src/libstd/sys/common/unwind/seh.rs
+++ b/src/libstd/sys/common/unwind/seh.rs
@@ -62,6 +62,7 @@
 
 // This function is provided by kernel32.dll
 extern "system" {
+    #[unwind]
     fn RaiseException(dwExceptionCode: DWORD,
                       dwExceptionFlags: DWORD,
                       nNumberOfArguments: DWORD,

diff --git a/src/libstd/sys/common/unwind/seh64_gnu.rs b/src/libstd/sys/common/unwind/seh64_gnu.rs
index 4d23794de244525ddb4b05bf969534858ad15f60..9478678fda995eee75c746ba7ad031169967aa03 100644 (file)
--- a/src/libstd/sys/common/unwind/seh64_gnu.rs
+++ b/src/libstd/sys/common/unwind/seh64_gnu.rs
@@ -93,6 +93,7 @@ pub enum EXCEPTION_DISPOSITION {
 
 // From kernel32.dll
 extern "system" {
+    #[unwind]
     fn RaiseException(dwExceptionCode: DWORD,
                       dwExceptionFlags: DWORD,
                       nNumberOfArguments: DWORD,
@@ -198,6 +199,7 @@ pub unsafe fn cleanup(ptr: *mut u8) -> Box<Any + Send + 'static> {
 
 #[lang = "eh_unwind_resume"]
 #[cfg(not(test))]
+#[unwind]
 unsafe extern fn rust_eh_unwind_resume(panic_ctx: LPVOID) {
     let params = [panic_ctx as ULONG_PTR];
     RaiseException(RUST_PANIC,

diff --git a/src/test/codegen/extern-functions.rs b/src/test/codegen/extern-functions.rs
new file mode 100644 (file)
index 0000000..4c30b5c
--- /dev/null
+++ b/src/test/codegen/extern-functions.rs
@@ -0,0 +1,23 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-flags: -C no-prepopulate-passes
+
+#![feature(unwind_attributes)]
+
+extern {
+// CHECK: Function Attrs: nounwind
+// CHECK-NEXT: declare void @extern_fn
+    fn extern_fn();
+// CHECK-NOT: Function Attrs: nounwind
+// CHECK: declare void @unwinding_extern_fn
+    #[unwind]
+    fn unwinding_extern_fn();
+}