From 0ec321f7b541fcbfbf20286beb497e6d9d3352b2 Mon Sep 17 00:00:00 2001 From: Alex Crichton Date: Fri, 8 Apr 2016 16:18:40 -0700 Subject: rustc: Implement custom panic runtimes This commit is an implementation of [RFC 1513] which allows applications to alter the behavior of panics at compile time. A new compiler flag, `-C panic`, is added and accepts the values `unwind` or `panic`, with the default being `unwind`. This model affects how code is generated for the local crate, skipping generation of landing pads with `-C panic=abort`. [RFC 1513]: https://github.com/rust-lang/rfcs/blob/master/text/1513-less-unwinding.md Panic implementations are then provided by crates tagged with `#![panic_runtime]` and lazily required by crates with `#![needs_panic_runtime]`. The panic strategy (`-C panic` value) of the panic runtime must match the final product, and if the panic strategy is not `abort` then the entire DAG must have the same panic strategy. With the `-C panic=abort` strategy, users can expect a stable method to disable generation of landing pads, improving optimization in niche scenarios, decreasing compile time, and decreasing output binary size. With the `-C panic=unwind` strategy users can expect the existing ability to isolate failure in Rust code from the outside world. Organizationally, this commit dismantles the `sys_common::unwind` module in favor of some bits moving part of it to `libpanic_unwind` and the rest into the `panicking` module in libstd. The custom panic runtime support is pretty similar to the custom allocator support with the only major difference being how the panic runtime is injected (takes the `-C panic` flag into account). --- src/test/codegen/lto-removes-invokes.rs | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 src/test/codegen/lto-removes-invokes.rs (limited to 'src/test/codegen') diff --git a/src/test/codegen/lto-removes-invokes.rs b/src/test/codegen/lto-removes-invokes.rs new file mode 100644 index 00000000000..b2f43489523 --- /dev/null +++ b/src/test/codegen/lto-removes-invokes.rs @@ -0,0 +1,31 @@ +// Copyright 2016 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 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// compile-flags: -C lto -C panic=abort -O +// no-prefer-dynamic + +fn main() { + foo(); +} + +#[no_mangle] +#[inline(never)] +fn foo() { + let _a = Box::new(3); + bar(); +// CHECK-LABEL: foo +// CHECK: call {{.*}} void @bar +} + +#[inline(never)] +#[no_mangle] +fn bar() { + println!("hello!"); +} -- cgit 1.4.1-3-g733a5