From e44ad61a2d8e3bac1d2cbf2467a7202250b8a77e Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Mon, 30 Apr 2018 10:55:24 +0200
Subject: [PATCH 01/12] implement #[panic_implementation]
---
src/libcore/macros.rs | 22 +++++
src/libcore/panic.rs | 6 +-
src/libcore/panicking.rs | 40 ++++++++
src/librustc/middle/dead.rs | 2 +-
src/librustc/middle/lang_items.rs | 5 +-
src/librustc/middle/weak_lang_items.rs | 2 +-
src/librustc_typeck/check/mod.rs | 44 ++++++++-
src/libstd/lib.rs | 2 +
src/libstd/panicking.rs | 97 ++++++++++++++++++-
src/libsyntax/feature_gate.rs | 9 ++
.../compile-fail/duplicate_entry_error.rs | 8 +-
.../feature-gate-panic-implementation.rs | 21 ++++
.../compile-fail/no_owned_box_lang_item.rs | 2 +-
.../panic-implementation-bad-signature-1.rs | 24 +++++
.../panic-implementation-bad-signature-2.rs | 25 +++++
.../panic-implementation-bad-signature-3.rs | 22 +++++
.../panic-implementation-duplicate.rs | 28 ++++++
...anic-implementation-requires-panic-info.rs | 26 +++++
.../auxiliary/panic-runtime-lang-items.rs | 6 +-
src/test/compile-fail/weak-lang-item.rs | 2 +-
src/test/ui/error-codes/E0152.rs | 2 +-
src/test/ui/error-codes/E0152.stderr | 2 +-
22 files changed, 379 insertions(+), 18 deletions(-)
create mode 100644 src/test/compile-fail/feature-gate-panic-implementation.rs
create mode 100644 src/test/compile-fail/panic-implementation-bad-signature-1.rs
create mode 100644 src/test/compile-fail/panic-implementation-bad-signature-2.rs
create mode 100644 src/test/compile-fail/panic-implementation-bad-signature-3.rs
create mode 100644 src/test/compile-fail/panic-implementation-duplicate.rs
create mode 100644 src/test/compile-fail/panic-implementation-requires-panic-info.rs
diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index c830c22ee5f50..f98626d939d10 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -9,6 +9,7 @@
// except according to those terms.
/// Entry point of thread panic, for details, see std::macros
+#[cfg(stage0)]
#[macro_export]
#[allow_internal_unstable]
#[stable(feature = "core", since = "1.6.0")]
@@ -28,6 +29,27 @@ macro_rules! panic {
});
}
+/// Entry point of thread panic, for details, see std::macros
+#[cfg(not(stage0))]
+#[macro_export]
+#[allow_internal_unstable]
+#[stable(feature = "core", since = "1.6.0")]
+macro_rules! panic {
+ () => (
+ panic!("explicit panic")
+ );
+ ($msg:expr) => ({
+ $crate::panicking::panic_payload($msg, &(file!(), line!(), __rust_unstable_column!()))
+ });
+ ($msg:expr,) => (
+ panic!($msg)
+ );
+ ($fmt:expr, $($arg:tt)+) => ({
+ $crate::panicking::panic_fmt(format_args!($fmt, $($arg)*),
+ &(file!(), line!(), __rust_unstable_column!()))
+ });
+}
+
/// Asserts that two expressions are equal to each other (using [`PartialEq`]).
///
/// On panic, this macro will print the values of the expressions with their
diff --git a/src/libcore/panic.rs b/src/libcore/panic.rs
index 27ec4aaac75de..37ae05309af1d 100644
--- a/src/libcore/panic.rs
+++ b/src/libcore/panic.rs
@@ -35,6 +35,7 @@ use fmt;
///
/// panic!("Normal panic");
/// ```
+#[cfg_attr(not(stage0), lang = "panic_info")]
#[stable(feature = "panic_hooks", since = "1.10.0")]
#[derive(Debug)]
pub struct PanicInfo<'a> {
@@ -53,7 +54,8 @@ impl<'a> PanicInfo<'a> {
pub fn internal_constructor(message: Option<&'a fmt::Arguments<'a>>,
location: Location<'a>)
-> Self {
- PanicInfo { payload: &(), location, message }
+ struct NoPayload;
+ PanicInfo { payload: &NoPayload, location, message }
}
#[doc(hidden)]
@@ -121,7 +123,7 @@ impl<'a> PanicInfo<'a> {
#[stable(feature = "panic_hooks", since = "1.10.0")]
pub fn location(&self) -> Option<&Location> {
// NOTE: If this is changed to sometimes return None,
- // deal with that case in std::panicking::default_hook.
+ // deal with that case in std::panicking::default_hook and std::panicking::begin_panic_fmt.
Some(&self.location)
}
}
diff --git a/src/libcore/panicking.rs b/src/libcore/panicking.rs
index 6b3dc75af4633..1470a01e0e6dd 100644
--- a/src/libcore/panicking.rs
+++ b/src/libcore/panicking.rs
@@ -36,7 +36,33 @@
and related macros",
issue = "0")]
+#[cfg(not(stage0))]
+use any::Any;
use fmt;
+#[cfg(not(stage0))]
+use panic::{Location, PanicInfo};
+
+#[cfg(not(stage0))]
+#[allow(improper_ctypes)] // PanicInfo contains a trait object which is not FFI safe
+extern "C" {
+ #[lang = "panic_impl"]
+ fn panic_impl(pi: &PanicInfo) -> !;
+}
+
+#[cfg(not(stage0))]
+#[cold] #[inline(never)]
+pub fn panic_payload<M>(msg: M, file_line_col: &(&'static str, u32, u32)) -> !
+where
+ M: Any + Send,
+{
+ let (file, line, col) = *file_line_col;
+ let mut pi = PanicInfo::internal_constructor(
+ None,
+ Location::internal_constructor(file, line, col),
+ );
+ pi.set_payload(&msg);
+ unsafe { panic_impl(&pi) }
+}
#[cold] #[inline(never)] // this is the slow path, always
#[lang = "panic"]
@@ -59,6 +85,7 @@ fn panic_bounds_check(file_line_col: &(&'static str, u32, u32),
len, index), file_line_col)
}
+#[cfg(stage0)]
#[cold] #[inline(never)]
pub fn panic_fmt(fmt: fmt::Arguments, file_line_col: &(&'static str, u32, u32)) -> ! {
#[allow(improper_ctypes)]
@@ -70,3 +97,16 @@ pub fn panic_fmt(fmt: fmt::Arguments, file_line_col: &(&'static str, u32, u32))
let (file, line, col) = *file_line_col;
unsafe { panic_impl(fmt, file, line, col) }
}
+
+#[cfg(not(stage0))]
+#[cold] #[inline(never)]
+pub fn panic_fmt(fmt: fmt::Arguments, file_line_col: &(&'static str, u32, u32)) -> ! {
+ struct NoPayload;
+
+ let (file, line, col) = *file_line_col;
+ let pi = PanicInfo::internal_constructor(
+ Some(&fmt),
+ Location::internal_constructor(file, line, col),
+ );
+ unsafe { panic_impl(&pi) }
+}
diff --git a/src/librustc/middle/dead.rs b/src/librustc/middle/dead.rs
index e3b2078971439..7ebc0d4a4de5a 100644
--- a/src/librustc/middle/dead.rs
+++ b/src/librustc/middle/dead.rs
@@ -284,7 +284,7 @@ impl<'a, 'tcx> Visitor<'tcx> for MarkSymbolVisitor<'a, 'tcx> {
fn has_allow_dead_code_or_lang_attr(tcx: TyCtxt,
id: ast::NodeId,
attrs: &[ast::Attribute]) -> bool {
- if attr::contains_name(attrs, "lang") {
+ if attr::contains_name(attrs, "lang") || attr::contains_name(attrs, "panic_implementation") {
return true;
}
diff --git a/src/librustc/middle/lang_items.rs b/src/librustc/middle/lang_items.rs
index d70f994e87ba7..fe676919a7d14 100644
--- a/src/librustc/middle/lang_items.rs
+++ b/src/librustc/middle/lang_items.rs
@@ -185,6 +185,8 @@ pub fn extract(attrs: &[ast::Attribute]) -> Option<(Symbol, Span)> {
if let Some(value) = attribute.value_str() {
return Some((value, attribute.span));
}
+ } else if attribute.check_name("panic_implementation") {
+ return Some((Symbol::intern("panic_impl"), attribute.span))
}
}
@@ -299,7 +301,8 @@ language_item_table! {
// lang item, but do not have it defined.
PanicFnLangItem, "panic", panic_fn;
PanicBoundsCheckFnLangItem, "panic_bounds_check", panic_bounds_check_fn;
- PanicFmtLangItem, "panic_fmt", panic_fmt;
+ PanicInfoLangItem, "panic_info", panic_info;
+ PanicImplLangItem, "panic_impl", panic_impl;
ExchangeMallocFnLangItem, "exchange_malloc", exchange_malloc_fn;
BoxFreeFnLangItem, "box_free", box_free_fn;
diff --git a/src/librustc/middle/weak_lang_items.rs b/src/librustc/middle/weak_lang_items.rs
index 42e4d3861bae3..3c2ea047218a7 100644
--- a/src/librustc/middle/weak_lang_items.rs
+++ b/src/librustc/middle/weak_lang_items.rs
@@ -148,7 +148,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for Context<'a, 'tcx> {
) }
weak_lang_items! {
- panic_fmt, PanicFmtLangItem, rust_begin_unwind;
+ panic_impl, PanicImplLangItem, rust_begin_unwind;
eh_personality, EhPersonalityLangItem, rust_eh_personality;
eh_unwind_resume, EhUnwindResumeLangItem, rust_eh_unwind_resume;
oom, OomLangItem, rust_oom;
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 90b974fb972c0..5c33eb5f0af12 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -96,7 +96,7 @@ use rustc::middle::region;
use rustc::mir::interpret::{GlobalId};
use rustc::ty::subst::{UnpackedKind, Subst, Substs};
use rustc::traits::{self, ObligationCause, ObligationCauseCode, TraitEngine};
-use rustc::ty::{self, Ty, TyCtxt, GenericParamDefKind, Visibility, ToPredicate};
+use rustc::ty::{self, Ty, TyCtxt, GenericParamDefKind, Visibility, ToPredicate, RegionKind};
use rustc::ty::adjustment::{Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability};
use rustc::ty::fold::TypeFoldable;
use rustc::ty::maps::Providers;
@@ -1129,6 +1129,48 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>,
}
}
+ // Check that a function marked as `#[panic_implementation]` has signature `fn(&PanicInfo) -> !`
+ if let Some(panic_impl_did) = fcx.tcx.lang_items().panic_impl() {
+ if panic_impl_did == fn_hir_id.owner_def_id() {
+ if let Some(panic_info_did) = fcx.tcx.lang_items().panic_info() {
+ if ret_ty.sty != ty::TyNever {
+ fcx.tcx.sess.span_err(
+ decl.output.span(),
+ "return type should be `!`",
+ );
+ }
+
+ let inputs = fn_sig.inputs();
+ let span = fcx.tcx.hir.span(fn_id);
+ if inputs.len() == 1 {
+ let arg_is_panic_info = match inputs[0].sty {
+ ty::TyRef(region, ty::TypeAndMut { ty, mutbl }) => match ty.sty {
+ ty::TyAdt(ref adt, _) => {
+ adt.did == panic_info_did &&
+ mutbl == hir::Mutability::MutImmutable &&
+ *region != RegionKind::ReStatic
+ },
+ _ => false,
+ },
+ _ => false,
+ };
+
+ if !arg_is_panic_info {
+ fcx.tcx.sess.span_err(
+ decl.inputs[0].span,
+ "argument should be `&PanicInfo`",
+ );
+ }
+ } else {
+ fcx.tcx.sess.span_err(span, "function should have one argument");
+ }
+ } else {
+ fcx.tcx.sess.err("language item required, but not found: `panic_info`");
+ }
+ }
+
+ }
+
(fcx, gen_ty)
}
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index f7d06852f2793..c576245edb755 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -317,6 +317,8 @@
#![cfg_attr(windows, feature(used))]
#![feature(doc_alias)]
#![feature(float_internals)]
+#![feature(panic_info_message)]
+#![cfg_attr(not(stage0), feature(panic_implementation))]
#![default_lib_allocator]
diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs
index 403056240bf57..6bb098310de22 100644
--- a/src/libstd/panicking.rs
+++ b/src/libstd/panicking.rs
@@ -186,7 +186,7 @@ fn default_hook(info: &PanicInfo) {
let location = info.location().unwrap(); // The current implementation always returns Some
- let msg = match info.payload().downcast_ref::<&'static str>() {
+ let msg = match info.payload().downcast_ref::<&str>() {
Some(s) => *s,
None => match info.payload().downcast_ref::<String>() {
Some(s) => &s[..],
@@ -319,6 +319,7 @@ pub fn panicking() -> bool {
/// Entry point of panic from the libcore crate.
#[cfg(not(test))]
+#[cfg(stage0)]
#[lang = "panic_fmt"]
#[unwind(allowed)]
pub extern fn rust_begin_panic(msg: fmt::Arguments,
@@ -328,12 +329,22 @@ pub extern fn rust_begin_panic(msg: fmt::Arguments,
begin_panic_fmt(&msg, &(file, line, col))
}
+/// Entry point of panic from the libcore crate.
+#[cfg(not(test))]
+#[cfg(not(stage0))]
+#[panic_implementation]
+#[unwind(allowed)]
+pub fn rust_begin_panic(info: &PanicInfo) -> ! {
+ continue_panic_fmt(&info)
+}
+
/// The entry point for panicking with a formatted message.
///
/// This is designed to reduce the amount of code required at the call
/// site as much as possible (so that `panic!()` has as low an impact
/// on (e.g.) the inlining of other functions as possible), by moving
/// the actual formatting into this shared place.
+#[cfg(stage0)]
#[unstable(feature = "libstd_sys_internals",
reason = "used by the panic! macro",
issue = "0")]
@@ -381,12 +392,92 @@ pub fn begin_panic_fmt(msg: &fmt::Arguments,
}
}
+/// The entry point for panicking with a formatted message.
+///
+/// This is designed to reduce the amount of code required at the call
+/// site as much as possible (so that `panic!()` has as low an impact
+/// on (e.g.) the inlining of other functions as possible), by moving
+/// the actual formatting into this shared place.
+#[cfg(not(stage0))]
+#[unstable(feature = "libstd_sys_internals",
+ reason = "used by the panic! macro",
+ issue = "0")]
+#[inline(never)] #[cold]
+pub fn begin_panic_fmt(msg: &fmt::Arguments,
+ file_line_col: &(&'static str, u32, u32)) -> ! {
+ let (file, line, col) = *file_line_col;
+ let info = PanicInfo::internal_constructor(
+ Some(msg),
+ Location::internal_constructor(file, line, col),
+ );
+ continue_panic_fmt(&info)
+}
+
+#[cfg(not(stage0))]
+fn continue_panic_fmt(info: &PanicInfo) -> ! {
+ use fmt::Write;
+
+ // We do two allocations here, unfortunately. But (a) they're
+ // required with the current scheme, and (b) we don't handle
+ // panic + OOM properly anyway (see comment in begin_panic
+ // below).
+
+ let loc = info.location().unwrap(); // The current implementation always returns Some
+ let file_line_col = (loc.file(), loc.line(), loc.column());
+ rust_panic_with_hook(
+ &mut PanicPayload::new(info.payload(), info.message()),
+ info.message(),
+ &file_line_col);
+
+ struct PanicPayload<'a> {
+ payload: &'a (Any + Send),
+ msg: Option<&'a fmt::Arguments<'a>>,
+ string: Option<String>,
+ }
+
+ impl<'a> PanicPayload<'a> {
+ fn new(payload: &'a (Any + Send), msg: Option<&'a fmt::Arguments<'a>>) -> PanicPayload<'a> {
+ PanicPayload { payload, msg, string: None }
+ }
+
+
+ fn fill(&mut self) -> Option<&mut String> {
+ if let Some(msg) = self.msg.take() {
+ Some(self.string.get_or_insert_with(|| {
+ let mut s = String::new();
+ drop(s.write_fmt(*msg));
+ s
+ }))
+ } else {
+ None
+ }
+ }
+ }
+
+ unsafe impl<'a> BoxMeUp for PanicPayload<'a> {
+ fn box_me_up(&mut self) -> *mut (Any + Send) {
+ if let Some(string) = self.fill() {
+ let contents = mem::replace(string, String::new());
+ Box::into_raw(Box::new(contents))
+ } else {
+ // We can't go from &(Any+Send) to Box<Any+Send> so the payload is lost here
+ struct NoPayload;
+ Box::into_raw(Box::new(NoPayload))
+ }
+ }
+
+ fn get(&mut self) -> &(Any + Send) {
+ self.payload
+ }
+ }
+}
+
/// This is the entry point of panicking for panic!() and assert!().
#[unstable(feature = "libstd_sys_internals",
reason = "used by the panic! macro",
issue = "0")]
#[inline(never)] #[cold] // avoid code bloat at the call sites as much as possible
-pub fn begin_panic<M: Any + Send>(msg: M, file_line_col: &(&'static str, u32, u32)) -> ! {
+pub fn begin_panic<M: Any + Send>(msg: M, file_line_col: &(&str, u32, u32)) -> ! {
// Note that this should be the only allocation performed in this code path.
// Currently this means that panic!() on OOM will invoke this code path,
// but then again we're not really ready for panic on OOM anyway. If
@@ -431,7 +522,7 @@ pub fn begin_panic<M: Any + Send>(msg: M, file_line_col: &(&'static str, u32, u3
/// abort or unwind.
fn rust_panic_with_hook(payload: &mut BoxMeUp,
message: Option<&fmt::Arguments>,
- file_line_col: &(&'static str, u32, u32)) -> ! {
+ file_line_col: &(&str, u32, u32)) -> ! {
let (file, line, col) = *file_line_col;
let panics = update_panic_count(1);
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 9b84713b0f90f..7349745fefea1 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -475,6 +475,9 @@ declare_features! (
// 'a: { break 'a; }
(active, label_break_value, "1.28.0", Some(48594), None),
+
+ // #[panic_implementation]
+ (active, panic_implementation, "1.28.0", Some(44489), None),
);
declare_features! (
@@ -1069,6 +1072,12 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
"attribute is currently unstable",
cfg_fn!(wasm_custom_section))),
+ // RFC 2070
+ ("panic_implementation", Normal, Gated(Stability::Unstable,
+ "panic_implementation",
+ "#[panic_implementation] is an unstable feature",
+ cfg_fn!(panic_implementation))),
+
// Crate level attributes
("crate_name", CrateLevel, Ungated),
("crate_type", CrateLevel, Ungated),
diff --git a/src/test/compile-fail/duplicate_entry_error.rs b/src/test/compile-fail/duplicate_entry_error.rs
index 485519e8c3d7e..176aa7cca5357 100644
--- a/src/test/compile-fail/duplicate_entry_error.rs
+++ b/src/test/compile-fail/duplicate_entry_error.rs
@@ -14,9 +14,11 @@
#![feature(lang_items)]
-#[lang = "panic_fmt"]
-fn panic_fmt() -> ! {
-//~^ ERROR: duplicate lang item found: `panic_fmt`.
+use std::panic::PanicInfo;
+
+#[lang = "panic_impl"]
+fn panic_impl(info: &PanicInfo) -> ! {
+//~^ ERROR: duplicate lang item found: `panic_impl`.
loop {}
}
diff --git a/src/test/compile-fail/feature-gate-panic-implementation.rs b/src/test/compile-fail/feature-gate-panic-implementation.rs
new file mode 100644
index 0000000000000..ae9fbc7b13bd5
--- /dev/null
+++ b/src/test/compile-fail/feature-gate-panic-implementation.rs
@@ -0,0 +1,21 @@
+// Copyright 2018 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 panic=abort
+
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation] //~ ERROR #[panic_implementation] is an unstable feature (see issue #44489)
+fn panic(info: &PanicInfo) -> ! {
+ loop {}
+}
diff --git a/src/test/compile-fail/no_owned_box_lang_item.rs b/src/test/compile-fail/no_owned_box_lang_item.rs
index 72eb687adc602..1c2bf1573dcc1 100644
--- a/src/test/compile-fail/no_owned_box_lang_item.rs
+++ b/src/test/compile-fail/no_owned_box_lang_item.rs
@@ -21,4 +21,4 @@ fn main() {
#[lang = "eh_personality"] extern fn eh_personality() {}
#[lang = "eh_unwind_resume"] extern fn eh_unwind_resume() {}
-#[lang = "panic_fmt"] fn panic_fmt() -> ! { loop {} }
+#[lang = "panic_impl"] fn panic_impl() -> ! { loop {} }
diff --git a/src/test/compile-fail/panic-implementation-bad-signature-1.rs b/src/test/compile-fail/panic-implementation-bad-signature-1.rs
new file mode 100644
index 0000000000000..fec11fdbd7ba1
--- /dev/null
+++ b/src/test/compile-fail/panic-implementation-bad-signature-1.rs
@@ -0,0 +1,24 @@
+// Copyright 2018 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 panic=abort
+
+#![feature(panic_implementation)]
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic(
+ info: PanicInfo, //~ ERROR argument should be `&PanicInfo`
+) -> () //~ ERROR return type should be `!`
+{
+}
diff --git a/src/test/compile-fail/panic-implementation-bad-signature-2.rs b/src/test/compile-fail/panic-implementation-bad-signature-2.rs
new file mode 100644
index 0000000000000..2a628c05699cc
--- /dev/null
+++ b/src/test/compile-fail/panic-implementation-bad-signature-2.rs
@@ -0,0 +1,25 @@
+// Copyright 2018 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 panic=abort
+
+#![feature(panic_implementation)]
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic(
+ info: &'static PanicInfo, //~ ERROR argument should be `&PanicInfo`
+) -> !
+{
+ loop {}
+}
diff --git a/src/test/compile-fail/panic-implementation-bad-signature-3.rs b/src/test/compile-fail/panic-implementation-bad-signature-3.rs
new file mode 100644
index 0000000000000..29337025b7076
--- /dev/null
+++ b/src/test/compile-fail/panic-implementation-bad-signature-3.rs
@@ -0,0 +1,22 @@
+// Copyright 2018 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 panic=abort
+
+#![feature(panic_implementation)]
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic() -> ! { //~ ERROR function should have one argument
+ loop {}
+}
diff --git a/src/test/compile-fail/panic-implementation-duplicate.rs b/src/test/compile-fail/panic-implementation-duplicate.rs
new file mode 100644
index 0000000000000..017113af409bb
--- /dev/null
+++ b/src/test/compile-fail/panic-implementation-duplicate.rs
@@ -0,0 +1,28 @@
+// Copyright 2018 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 panic=abort
+
+#![feature(lang_items)]
+#![feature(panic_implementation)]
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic(info: &PanicInfo) -> ! {
+ loop {}
+}
+
+#[lang = "panic_impl"]
+fn panic2(info: &PanicInfo) -> ! { //~ ERROR duplicate lang item found: `panic_impl`.
+ loop {}
+}
diff --git a/src/test/compile-fail/panic-implementation-requires-panic-info.rs b/src/test/compile-fail/panic-implementation-requires-panic-info.rs
new file mode 100644
index 0000000000000..597f44d98326d
--- /dev/null
+++ b/src/test/compile-fail/panic-implementation-requires-panic-info.rs
@@ -0,0 +1,26 @@
+// Copyright 2018 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 panic=abort
+// error-pattern: language item required, but not found: `panic_info`
+
+#![feature(lang_items)]
+#![feature(no_core)]
+#![feature(panic_implementation)]
+#![no_core]
+#![no_main]
+
+#[panic_implementation]
+fn panic() -> ! {
+ loop {}
+}
+
+#[lang = "sized"]
+trait Sized {}
diff --git a/src/test/compile-fail/panic-runtime/auxiliary/panic-runtime-lang-items.rs b/src/test/compile-fail/panic-runtime/auxiliary/panic-runtime-lang-items.rs
index fbf70b3d3fefe..d9848a554aba5 100644
--- a/src/test/compile-fail/panic-runtime/auxiliary/panic-runtime-lang-items.rs
+++ b/src/test/compile-fail/panic-runtime/auxiliary/panic-runtime-lang-items.rs
@@ -15,8 +15,10 @@
#![no_std]
#![feature(lang_items)]
-#[lang = "panic_fmt"]
-fn panic_fmt() {}
+use core::panic::PanicInfo;
+
+#[lang = "panic_impl"]
+fn panic_impl(info: &PanicInfo) -> ! { loop {} }
#[lang = "eh_personality"]
fn eh_personality() {}
#[lang = "eh_unwind_resume"]
diff --git a/src/test/compile-fail/weak-lang-item.rs b/src/test/compile-fail/weak-lang-item.rs
index 8579611b9380a..7b988c3595f5e 100644
--- a/src/test/compile-fail/weak-lang-item.rs
+++ b/src/test/compile-fail/weak-lang-item.rs
@@ -9,7 +9,7 @@
// except according to those terms.
// aux-build:weak-lang-items.rs
-// error-pattern: language item required, but not found: `panic_fmt`
+// error-pattern: language item required, but not found: `panic_impl`
// error-pattern: language item required, but not found: `eh_personality`
// ignore-wasm32-bare compiled with panic=abort, personality not required
diff --git a/src/test/ui/error-codes/E0152.rs b/src/test/ui/error-codes/E0152.rs
index ae501b94e3f05..8fbad7b3ff301 100644
--- a/src/test/ui/error-codes/E0152.rs
+++ b/src/test/ui/error-codes/E0152.rs
@@ -10,7 +10,7 @@
#![feature(lang_items)]
-#[lang = "panic_fmt"]
+#[lang = "panic_impl"]
struct Foo; //~ ERROR E0152
fn main() {
diff --git a/src/test/ui/error-codes/E0152.stderr b/src/test/ui/error-codes/E0152.stderr
index f67022bd6d3f9..c7f5f362efb28 100644
--- a/src/test/ui/error-codes/E0152.stderr
+++ b/src/test/ui/error-codes/E0152.stderr
@@ -1,4 +1,4 @@
-error[E0152]: duplicate lang item found: `panic_fmt`.
+error[E0152]: duplicate lang item found: `panic_impl`.
--> $DIR/E0152.rs:14:1
|
LL | struct Foo; //~ ERROR E0152
From 63f18e108af98be931465fa0d2e7e998c5542aab Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Mon, 30 Apr 2018 10:57:11 +0200
Subject: [PATCH 02/12] s/panic_fmt/panic_impl/g in docs
---
.../src/language-features/lang-items.md | 25 ++++++++-----------
.../src/language-features/used.md | 10 +++++---
src/libcore/lib.rs | 2 +-
src/librustc/diagnostics.rs | 6 ++---
4 files changed, 22 insertions(+), 21 deletions(-)
diff --git a/src/doc/unstable-book/src/language-features/lang-items.md b/src/doc/unstable-book/src/language-features/lang-items.md
index 6a7aea7f1c27e..bac619fd4a30d 100644
--- a/src/doc/unstable-book/src/language-features/lang-items.md
+++ b/src/doc/unstable-book/src/language-features/lang-items.md
@@ -19,6 +19,7 @@ sugar for dynamic allocations via `malloc` and `free`:
#![feature(lang_items, box_syntax, start, libc, core_intrinsics)]
#![no_std]
use core::intrinsics;
+use core::panic::PanicInfo;
extern crate libc;
@@ -50,7 +51,7 @@ fn main(_argc: isize, _argv: *const *const u8) -> isize {
}
#[lang = "eh_personality"] extern fn rust_eh_personality() {}
-#[lang = "panic_fmt"] extern fn rust_begin_panic() -> ! { unsafe { intrinsics::abort() } }
+#[lang = "panic_impl"] extern fn rust_begin_panic(info: &PanicInfo) -> ! { unsafe { intrinsics::abort() } }
#[lang = "eh_unwind_resume"] extern fn rust_eh_unwind_resume() {}
#[no_mangle] pub extern fn rust_eh_register_frames () {}
#[no_mangle] pub extern fn rust_eh_unregister_frames () {}
@@ -110,6 +111,7 @@ in the same format as C:
#![feature(start)]
#![no_std]
use core::intrinsics;
+use core::panic::PanicInfo;
// Pull in the system libc library for what crt0.o likely requires.
extern crate libc;
@@ -134,12 +136,9 @@ pub extern fn rust_eh_personality() {
pub extern fn rust_eh_unwind_resume() {
}
-#[lang = "panic_fmt"]
+#[lang = "panic_impl"]
#[no_mangle]
-pub extern fn rust_begin_panic(_msg: core::fmt::Arguments,
- _file: &'static str,
- _line: u32,
- _column: u32) -> ! {
+pub extern fn rust_begin_panic(info: &PanicInfo) -> ! {
unsafe { intrinsics::abort() }
}
```
@@ -155,6 +154,7 @@ compiler's name mangling too:
#![no_std]
#![no_main]
use core::intrinsics;
+use core::panic::PanicInfo;
// Pull in the system libc library for what crt0.o likely requires.
extern crate libc;
@@ -179,12 +179,9 @@ pub extern fn rust_eh_personality() {
pub extern fn rust_eh_unwind_resume() {
}
-#[lang = "panic_fmt"]
+#[lang = "panic_impl"]
#[no_mangle]
-pub extern fn rust_begin_panic(_msg: core::fmt::Arguments,
- _file: &'static str,
- _line: u32,
- _column: u32) -> ! {
+pub extern fn rust_begin_panic(info: &PanicInfo) -> ! {
unsafe { intrinsics::abort() }
}
```
@@ -215,7 +212,7 @@ called. The language item's name is `eh_personality`.
The second function, `rust_begin_panic`, is also used by the failure mechanisms of the
compiler. When a panic happens, this controls the message that's displayed on
-the screen. While the language item's name is `panic_fmt`, the symbol name is
+the screen. While the language item's name is `panic_impl`, the symbol name is
`rust_begin_panic`.
A third function, `rust_eh_unwind_resume`, is also needed if the `custom_unwind_resume`
@@ -259,8 +256,8 @@ the source code.
- `msvc_try_filter`: `libpanic_unwind/seh.rs` (SEH)
- `panic`: `libcore/panicking.rs`
- `panic_bounds_check`: `libcore/panicking.rs`
- - `panic_fmt`: `libcore/panicking.rs`
- - `panic_fmt`: `libstd/panicking.rs`
+ - `panic_impl`: `libcore/panicking.rs`
+ - `panic_impl`: `libstd/panicking.rs`
- Allocations
- `owned_box`: `liballoc/boxed.rs`
- `exchange_malloc`: `liballoc/heap.rs`
diff --git a/src/doc/unstable-book/src/language-features/used.md b/src/doc/unstable-book/src/language-features/used.md
index 75a8b2774f422..c3b7f2e41e15b 100644
--- a/src/doc/unstable-book/src/language-features/used.md
+++ b/src/doc/unstable-book/src/language-features/used.md
@@ -87,11 +87,13 @@ This condition can be met using `#[used]` and `#[link_section]` plus a linker
script.
``` rust,ignore
-#![feature(lang_items)]
+#![feature(panic_implementation)]
#![feature(used)]
#![no_main]
#![no_std]
+use core::panic::PanicInfo;
+
extern "C" fn reset_handler() -> ! {
loop {}
}
@@ -100,8 +102,10 @@ extern "C" fn reset_handler() -> ! {
#[used]
static RESET_HANDLER: extern "C" fn() -> ! = reset_handler;
-#[lang = "panic_fmt"]
-fn panic_fmt() {}
+#[panic_implementation]
+fn panic_impl(info: &PanicInfo) -> ! {
+ loop {}
+}
```
``` text
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 32cf31231c301..e6ab64a331272 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -41,7 +41,7 @@
//! dictate the panic message, the file at which panic was invoked, and the
//! line and column inside the file. It is up to consumers of this core
//! library to define this panic function; it is only required to never
-//! return. This requires a `lang` attribute named `panic_fmt`.
+//! return. This requires a `lang` attribute named `panic_impl`.
//!
//! * `rust_eh_personality` - is used by the failure mechanisms of the
//! compiler. This is often mapped to GCC's personality function, but crates
diff --git a/src/librustc/diagnostics.rs b/src/librustc/diagnostics.rs
index 2662e70999196..61f05ca347358 100644
--- a/src/librustc/diagnostics.rs
+++ b/src/librustc/diagnostics.rs
@@ -637,8 +637,8 @@ Erroneous code example:
```compile_fail,E0152
#![feature(lang_items)]
-#[lang = "panic_fmt"]
-struct Foo; // error: duplicate lang item found: `panic_fmt`
+#[lang = "panic_impl"]
+struct Foo; // error: duplicate lang item found: `panic_impl`
```
Lang items are already implemented in the standard library. Unless you are
@@ -824,7 +824,7 @@ A list of available external lang items is available in
#![feature(lang_items)]
extern "C" {
- #[lang = "panic_fmt"] // ok!
+ #[lang = "panic_impl"] // ok!
fn cake();
}
```
From eaef110890837283a1504eb200cab1eba03650ea Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Tue, 1 May 2018 03:02:39 +0200
Subject: [PATCH 03/12] format payload if possible instead of returning
"Box<Any>"
---
src/libstd/panicking.rs | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs
index 6bb098310de22..1f80fb6f738bd 100644
--- a/src/libstd/panicking.rs
+++ b/src/libstd/panicking.rs
@@ -440,12 +440,11 @@ fn continue_panic_fmt(info: &PanicInfo) -> ! {
PanicPayload { payload, msg, string: None }
}
-
fn fill(&mut self) -> Option<&mut String> {
- if let Some(msg) = self.msg.take() {
+ if let Some(msg) = self.msg.cloned() {
Some(self.string.get_or_insert_with(|| {
let mut s = String::new();
- drop(s.write_fmt(*msg));
+ drop(s.write_fmt(msg));
s
}))
} else {
@@ -459,6 +458,10 @@ fn continue_panic_fmt(info: &PanicInfo) -> ! {
if let Some(string) = self.fill() {
let contents = mem::replace(string, String::new());
Box::into_raw(Box::new(contents))
+ } else if let Some(s) = self.payload.downcast_ref::<&str>() {
+ Box::into_raw(Box::new(s.to_owned()))
+ } else if let Some(s) = self.payload.downcast_ref::<String>() {
+ Box::into_raw(Box::new(s.clone()))
} else {
// We can't go from &(Any+Send) to Box<Any+Send> so the payload is lost here
struct NoPayload;
@@ -467,7 +470,11 @@ fn continue_panic_fmt(info: &PanicInfo) -> ! {
}
fn get(&mut self) -> &(Any + Send) {
- self.payload
+ if let Some(s) = self.fill() {
+ s
+ } else {
+ self.payload
+ }
}
}
}
From b442348d53ca37b6d22cd6e40c305d89f7782538 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Tue, 1 May 2018 03:03:20 +0200
Subject: [PATCH 04/12] remove unused `struct NoPayload`
---
src/libcore/panicking.rs | 2 --
1 file changed, 2 deletions(-)
diff --git a/src/libcore/panicking.rs b/src/libcore/panicking.rs
index 1470a01e0e6dd..71a1eb2f7a4e6 100644
--- a/src/libcore/panicking.rs
+++ b/src/libcore/panicking.rs
@@ -101,8 +101,6 @@ pub fn panic_fmt(fmt: fmt::Arguments, file_line_col: &(&'static str, u32, u32))
#[cfg(not(stage0))]
#[cold] #[inline(never)]
pub fn panic_fmt(fmt: fmt::Arguments, file_line_col: &(&'static str, u32, u32)) -> ! {
- struct NoPayload;
-
let (file, line, col) = *file_line_col;
let pi = PanicInfo::internal_constructor(
Some(&fmt),
From eb1936141611afa8ad9034c4093e1539df36548c Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Tue, 1 May 2018 03:04:42 +0200
Subject: [PATCH 05/12] document that `panic_impl` never passes the FFI
boundary
---
src/libcore/panicking.rs | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/src/libcore/panicking.rs b/src/libcore/panicking.rs
index 71a1eb2f7a4e6..4b4fa73c47810 100644
--- a/src/libcore/panicking.rs
+++ b/src/libcore/panicking.rs
@@ -42,9 +42,10 @@ use fmt;
#[cfg(not(stage0))]
use panic::{Location, PanicInfo};
+// NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call
#[cfg(not(stage0))]
#[allow(improper_ctypes)] // PanicInfo contains a trait object which is not FFI safe
-extern "C" {
+extern "Rust" {
#[lang = "panic_impl"]
fn panic_impl(pi: &PanicInfo) -> !;
}
From 430ad769008c0aaa40949a1d98a6f0e18e35ec65 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Wed, 16 May 2018 14:07:58 +0200
Subject: [PATCH 06/12] undo payload in core::panic! changes
---
src/libcore/macros.rs | 22 --------
src/libcore/panicking.rs | 32 +++---------
src/libstd/panicking.rs | 109 +++++++++++----------------------------
3 files changed, 37 insertions(+), 126 deletions(-)
diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index f98626d939d10..c830c22ee5f50 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -9,7 +9,6 @@
// except according to those terms.
/// Entry point of thread panic, for details, see std::macros
-#[cfg(stage0)]
#[macro_export]
#[allow_internal_unstable]
#[stable(feature = "core", since = "1.6.0")]
@@ -29,27 +28,6 @@ macro_rules! panic {
});
}
-/// Entry point of thread panic, for details, see std::macros
-#[cfg(not(stage0))]
-#[macro_export]
-#[allow_internal_unstable]
-#[stable(feature = "core", since = "1.6.0")]
-macro_rules! panic {
- () => (
- panic!("explicit panic")
- );
- ($msg:expr) => ({
- $crate::panicking::panic_payload($msg, &(file!(), line!(), __rust_unstable_column!()))
- });
- ($msg:expr,) => (
- panic!($msg)
- );
- ($fmt:expr, $($arg:tt)+) => ({
- $crate::panicking::panic_fmt(format_args!($fmt, $($arg)*),
- &(file!(), line!(), __rust_unstable_column!()))
- });
-}
-
/// Asserts that two expressions are equal to each other (using [`PartialEq`]).
///
/// On panic, this macro will print the values of the expressions with their
diff --git a/src/libcore/panicking.rs b/src/libcore/panicking.rs
index 4b4fa73c47810..0d4f8d1141e73 100644
--- a/src/libcore/panicking.rs
+++ b/src/libcore/panicking.rs
@@ -36,35 +36,10 @@
and related macros",
issue = "0")]
-#[cfg(not(stage0))]
-use any::Any;
use fmt;
#[cfg(not(stage0))]
use panic::{Location, PanicInfo};
-// NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call
-#[cfg(not(stage0))]
-#[allow(improper_ctypes)] // PanicInfo contains a trait object which is not FFI safe
-extern "Rust" {
- #[lang = "panic_impl"]
- fn panic_impl(pi: &PanicInfo) -> !;
-}
-
-#[cfg(not(stage0))]
-#[cold] #[inline(never)]
-pub fn panic_payload<M>(msg: M, file_line_col: &(&'static str, u32, u32)) -> !
-where
- M: Any + Send,
-{
- let (file, line, col) = *file_line_col;
- let mut pi = PanicInfo::internal_constructor(
- None,
- Location::internal_constructor(file, line, col),
- );
- pi.set_payload(&msg);
- unsafe { panic_impl(&pi) }
-}
-
#[cold] #[inline(never)] // this is the slow path, always
#[lang = "panic"]
pub fn panic(expr_file_line_col: &(&'static str, &'static str, u32, u32)) -> ! {
@@ -102,6 +77,13 @@ pub fn panic_fmt(fmt: fmt::Arguments, file_line_col: &(&'static str, u32, u32))
#[cfg(not(stage0))]
#[cold] #[inline(never)]
pub fn panic_fmt(fmt: fmt::Arguments, file_line_col: &(&'static str, u32, u32)) -> ! {
+ // NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call
+ #[allow(improper_ctypes)] // PanicInfo contains a trait object which is not FFI safe
+ extern "Rust" {
+ #[lang = "panic_impl"]
+ fn panic_impl(pi: &PanicInfo) -> !;
+ }
+
let (file, line, col) = *file_line_col;
let pi = PanicInfo::internal_constructor(
Some(&fmt),
diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs
index 1f80fb6f738bd..9d8052143b98e 100644
--- a/src/libstd/panicking.rs
+++ b/src/libstd/panicking.rs
@@ -186,7 +186,7 @@ fn default_hook(info: &PanicInfo) {
let location = info.location().unwrap(); // The current implementation always returns Some
- let msg = match info.payload().downcast_ref::<&str>() {
+ let msg = match info.payload().downcast_ref::<&'static str>() {
Some(s) => *s,
None => match info.payload().downcast_ref::<String>() {
Some(s) => &s[..],
@@ -351,44 +351,45 @@ pub fn rust_begin_panic(info: &PanicInfo) -> ! {
#[inline(never)] #[cold]
pub fn begin_panic_fmt(msg: &fmt::Arguments,
file_line_col: &(&'static str, u32, u32)) -> ! {
- use fmt::Write;
-
// We do two allocations here, unfortunately. But (a) they're
// required with the current scheme, and (b) we don't handle
// panic + OOM properly anyway (see comment in begin_panic
// below).
rust_panic_with_hook(&mut PanicPayload::new(msg), Some(msg), file_line_col);
+}
+
+// NOTE(stage0) move into `continue_panic_fmt` on next stage0 update
+struct PanicPayload<'a> {
+ inner: &'a fmt::Arguments<'a>,
+ string: Option<String>,
+}
- struct PanicPayload<'a> {
- inner: &'a fmt::Arguments<'a>,
- string: Option<String>,
+impl<'a> PanicPayload<'a> {
+ fn new(inner: &'a fmt::Arguments<'a>) -> PanicPayload<'a> {
+ PanicPayload { inner, string: None }
}
- impl<'a> PanicPayload<'a> {
- fn new(inner: &'a fmt::Arguments<'a>) -> PanicPayload<'a> {
- PanicPayload { inner, string: None }
- }
+ fn fill(&mut self) -> &mut String {
+ use fmt::Write;
- fn fill(&mut self) -> &mut String {
- let inner = self.inner;
- self.string.get_or_insert_with(|| {
- let mut s = String::new();
- drop(s.write_fmt(*inner));
- s
- })
- }
+ let inner = self.inner;
+ self.string.get_or_insert_with(|| {
+ let mut s = String::new();
+ drop(s.write_fmt(*inner));
+ s
+ })
}
+}
- unsafe impl<'a> BoxMeUp for PanicPayload<'a> {
- fn box_me_up(&mut self) -> *mut (Any + Send) {
- let contents = mem::replace(self.fill(), String::new());
- Box::into_raw(Box::new(contents))
- }
+unsafe impl<'a> BoxMeUp for PanicPayload<'a> {
+ fn box_me_up(&mut self) -> *mut (Any + Send) {
+ let contents = mem::replace(self.fill(), String::new());
+ Box::into_raw(Box::new(contents))
+ }
- fn get(&mut self) -> &(Any + Send) {
- self.fill()
- }
+ fn get(&mut self) -> &(Any + Send) {
+ self.fill()
}
}
@@ -415,68 +416,18 @@ pub fn begin_panic_fmt(msg: &fmt::Arguments,
#[cfg(not(stage0))]
fn continue_panic_fmt(info: &PanicInfo) -> ! {
- use fmt::Write;
-
// We do two allocations here, unfortunately. But (a) they're
// required with the current scheme, and (b) we don't handle
// panic + OOM properly anyway (see comment in begin_panic
// below).
let loc = info.location().unwrap(); // The current implementation always returns Some
+ let msg = info.message().unwrap(); // The current implementation always returns Some
let file_line_col = (loc.file(), loc.line(), loc.column());
rust_panic_with_hook(
- &mut PanicPayload::new(info.payload(), info.message()),
+ &mut PanicPayload::new(msg),
info.message(),
&file_line_col);
-
- struct PanicPayload<'a> {
- payload: &'a (Any + Send),
- msg: Option<&'a fmt::Arguments<'a>>,
- string: Option<String>,
- }
-
- impl<'a> PanicPayload<'a> {
- fn new(payload: &'a (Any + Send), msg: Option<&'a fmt::Arguments<'a>>) -> PanicPayload<'a> {
- PanicPayload { payload, msg, string: None }
- }
-
- fn fill(&mut self) -> Option<&mut String> {
- if let Some(msg) = self.msg.cloned() {
- Some(self.string.get_or_insert_with(|| {
- let mut s = String::new();
- drop(s.write_fmt(msg));
- s
- }))
- } else {
- None
- }
- }
- }
-
- unsafe impl<'a> BoxMeUp for PanicPayload<'a> {
- fn box_me_up(&mut self) -> *mut (Any + Send) {
- if let Some(string) = self.fill() {
- let contents = mem::replace(string, String::new());
- Box::into_raw(Box::new(contents))
- } else if let Some(s) = self.payload.downcast_ref::<&str>() {
- Box::into_raw(Box::new(s.to_owned()))
- } else if let Some(s) = self.payload.downcast_ref::<String>() {
- Box::into_raw(Box::new(s.clone()))
- } else {
- // We can't go from &(Any+Send) to Box<Any+Send> so the payload is lost here
- struct NoPayload;
- Box::into_raw(Box::new(NoPayload))
- }
- }
-
- fn get(&mut self) -> &(Any + Send) {
- if let Some(s) = self.fill() {
- s
- } else {
- self.payload
- }
- }
- }
}
/// This is the entry point of panicking for panic!() and assert!().
@@ -484,7 +435,7 @@ fn continue_panic_fmt(info: &PanicInfo) -> ! {
reason = "used by the panic! macro",
issue = "0")]
#[inline(never)] #[cold] // avoid code bloat at the call sites as much as possible
-pub fn begin_panic<M: Any + Send>(msg: M, file_line_col: &(&str, u32, u32)) -> ! {
+pub fn begin_panic<M: Any + Send>(msg: M, file_line_col: &(&'static str, u32, u32)) -> ! {
// Note that this should be the only allocation performed in this code path.
// Currently this means that panic!() on OOM will invoke this code path,
// but then again we're not really ready for panic on OOM anyway. If
From 86a07696219fecfe4444aeb727d02ad8a4ebcda0 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Wed, 16 May 2018 19:55:57 +0200
Subject: [PATCH 07/12] fix after rebase
---
src/librustc_typeck/check/mod.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 5c33eb5f0af12..23ebf418195f2 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -1144,7 +1144,7 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>,
let span = fcx.tcx.hir.span(fn_id);
if inputs.len() == 1 {
let arg_is_panic_info = match inputs[0].sty {
- ty::TyRef(region, ty::TypeAndMut { ty, mutbl }) => match ty.sty {
+ ty::TyRef(region, ty, mutbl) => match ty.sty {
ty::TyAdt(ref adt, _) => {
adt.did == panic_info_did &&
mutbl == hir::Mutability::MutImmutable &&
From 4c84d382ed87521a5b98b30f508366111dbbc7d5 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Wed, 16 May 2018 19:56:24 +0200
Subject: [PATCH 08/12] remove #[unwind(allowed)]
not required because this is a Rust function
---
src/libstd/panicking.rs | 1 -
1 file changed, 1 deletion(-)
diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs
index 9d8052143b98e..0808efa2ecea5 100644
--- a/src/libstd/panicking.rs
+++ b/src/libstd/panicking.rs
@@ -321,7 +321,6 @@ pub fn panicking() -> bool {
#[cfg(not(test))]
#[cfg(stage0)]
#[lang = "panic_fmt"]
-#[unwind(allowed)]
pub extern fn rust_begin_panic(msg: fmt::Arguments,
file: &'static str,
line: u32,
From da2ee5dcb29b3675cb342c9bc240a22eea9cc2b7 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Tue, 29 May 2018 11:23:00 +0200
Subject: [PATCH 09/12] reject `fn panic_impl<T>(_: &PanicInfo) -> !`
---
src/librustc_typeck/check/mod.rs | 15 ++++++++++--
.../panic-implementation-bad-signature-4.rs | 23 +++++++++++++++++++
2 files changed, 36 insertions(+), 2 deletions(-)
create mode 100644 src/test/compile-fail/panic-implementation-bad-signature-4.rs
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 23ebf418195f2..d54f29e6b9980 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -130,7 +130,7 @@ use syntax_pos::{self, BytePos, Span, MultiSpan};
use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
use rustc::hir::itemlikevisit::ItemLikeVisitor;
use rustc::hir::map::Node;
-use rustc::hir::{self, PatKind};
+use rustc::hir::{self, PatKind, Item_};
use rustc::middle::lang_items;
mod autoderef;
@@ -1133,7 +1133,7 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>,
if let Some(panic_impl_did) = fcx.tcx.lang_items().panic_impl() {
if panic_impl_did == fn_hir_id.owner_def_id() {
if let Some(panic_info_did) = fcx.tcx.lang_items().panic_info() {
- if ret_ty.sty != ty::TyNever {
+ if declared_ret_ty.sty != ty::TyNever {
fcx.tcx.sess.span_err(
decl.output.span(),
"return type should be `!`",
@@ -1161,6 +1161,17 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>,
"argument should be `&PanicInfo`",
);
}
+
+ if let Node::NodeItem(item) = fcx.tcx.hir.get(fn_id) {
+ if let Item_::ItemFn(_, _, _, _, ref generics, _) = item.node {
+ if !generics.params.is_empty() {
+ fcx.tcx.sess.span_err(
+ span,
+ "`#[panic_implementation]` function should have no type parameters",
+ );
+ }
+ }
+ }
} else {
fcx.tcx.sess.span_err(span, "function should have one argument");
}
diff --git a/src/test/compile-fail/panic-implementation-bad-signature-4.rs b/src/test/compile-fail/panic-implementation-bad-signature-4.rs
new file mode 100644
index 0000000000000..d5f942ba2d62f
--- /dev/null
+++ b/src/test/compile-fail/panic-implementation-bad-signature-4.rs
@@ -0,0 +1,23 @@
+// Copyright 2018 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 panic=abort
+
+#![feature(panic_implementation)]
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic<T>(pi: &PanicInfo) -> ! {
+ //~^ ERROR `#[panic_implementation]` function should have no type parameters
+ loop {}
+}
From a174f2ab7c061ece4529ffa9b897236761298717 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Tue, 29 May 2018 12:33:11 +0200
Subject: [PATCH 10/12] add more tests
---
.../compile-fail/auxiliary/some-panic-impl.rs | 22 ++++++++++++++
.../compile-fail/panic-implementation-std.rs | 22 ++++++++++++++
.../panic-implementation-twice.rs | 29 +++++++++++++++++++
.../run-make/panic-impl-transitive/Makefile | 7 +++++
.../panic-impl-consumer.rs | 15 ++++++++++
.../panic-impl-provider.rs | 20 +++++++++++++
6 files changed, 115 insertions(+)
create mode 100644 src/test/compile-fail/auxiliary/some-panic-impl.rs
create mode 100644 src/test/compile-fail/panic-implementation-std.rs
create mode 100644 src/test/compile-fail/panic-implementation-twice.rs
create mode 100644 src/test/run-make/panic-impl-transitive/Makefile
create mode 100644 src/test/run-make/panic-impl-transitive/panic-impl-consumer.rs
create mode 100644 src/test/run-make/panic-impl-transitive/panic-impl-provider.rs
diff --git a/src/test/compile-fail/auxiliary/some-panic-impl.rs b/src/test/compile-fail/auxiliary/some-panic-impl.rs
new file mode 100644
index 0000000000000..db16ac325ac59
--- /dev/null
+++ b/src/test/compile-fail/auxiliary/some-panic-impl.rs
@@ -0,0 +1,22 @@
+// Copyright 2018 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.
+
+// no-prefer-dynamic
+
+#![crate_type = "rlib"]
+#![feature(panic_implementation)]
+#![no_std]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic(info: &PanicInfo) -> ! {
+ loop {}
+}
diff --git a/src/test/compile-fail/panic-implementation-std.rs b/src/test/compile-fail/panic-implementation-std.rs
new file mode 100644
index 0000000000000..f25cd3605c1dd
--- /dev/null
+++ b/src/test/compile-fail/panic-implementation-std.rs
@@ -0,0 +1,22 @@
+// Copyright 2018 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.
+
+// error-pattern: duplicate lang item found: `panic_impl`.
+
+#![feature(panic_implementation)]
+
+use std::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic(info: PanicInfo) -> ! {
+ loop {}
+}
+
+fn main() {}
diff --git a/src/test/compile-fail/panic-implementation-twice.rs b/src/test/compile-fail/panic-implementation-twice.rs
new file mode 100644
index 0000000000000..78dc545c036f8
--- /dev/null
+++ b/src/test/compile-fail/panic-implementation-twice.rs
@@ -0,0 +1,29 @@
+// Copyright 2018 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.
+
+// aux-build:some-panic-impl.rs
+
+#![feature(panic_implementation)]
+#![feature(lang_items)]
+#![no_std]
+#![no_main]
+
+extern crate some_panic_impl;
+
+use core::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic(info: &PanicInfo) -> ! {
+ //~^ error duplicate lang item found: `panic_impl`
+ loop {}
+}
+
+#[lang = "eh_personality"]
+fn eh() {}
diff --git a/src/test/run-make/panic-impl-transitive/Makefile b/src/test/run-make/panic-impl-transitive/Makefile
new file mode 100644
index 0000000000000..1714578b2ba28
--- /dev/null
+++ b/src/test/run-make/panic-impl-transitive/Makefile
@@ -0,0 +1,7 @@
+-include ../../run-make-fulldeps/tools.mk
+
+# NOTE we use --emit=llvm-ir to avoid running the linker (linking will fail because there's no main
+# in this crate)
+all:
+ $(RUSTC) panic-impl-provider.rs
+ $(RUSTC) panic-impl-consumer.rs -C panic=abort --emit=llvm-ir -L $(TMPDIR)
diff --git a/src/test/run-make/panic-impl-transitive/panic-impl-consumer.rs b/src/test/run-make/panic-impl-transitive/panic-impl-consumer.rs
new file mode 100644
index 0000000000000..592fab8be85ec
--- /dev/null
+++ b/src/test/run-make/panic-impl-transitive/panic-impl-consumer.rs
@@ -0,0 +1,15 @@
+// Copyright 2018 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.
+
+#![no_std]
+#![no_main]
+
+// this crate provides the `panic_impl` lang item so we don't need to define it here
+extern crate panic_impl_provider;
diff --git a/src/test/run-make/panic-impl-transitive/panic-impl-provider.rs b/src/test/run-make/panic-impl-transitive/panic-impl-provider.rs
new file mode 100644
index 0000000000000..46cdf2e2fa55e
--- /dev/null
+++ b/src/test/run-make/panic-impl-transitive/panic-impl-provider.rs
@@ -0,0 +1,20 @@
+// Copyright 2018 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.
+
+#![crate_type = "rlib"]
+#![feature(panic_implementation)]
+#![no_std]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation]
+fn panic(info: &PanicInfo) -> ! {
+ loop {}
+}
From 948ed24a091a569595de6a417f54dbb252f34cd7 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Tue, 29 May 2018 14:25:35 +0200
Subject: [PATCH 11/12] fix tidy error
---
src/librustc_typeck/check/mod.rs | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index d54f29e6b9980..c2c71d90f0674 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -1167,7 +1167,8 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>,
if !generics.params.is_empty() {
fcx.tcx.sess.span_err(
span,
- "`#[panic_implementation]` function should have no type parameters",
+ "`#[panic_implementation]` function should have no type \
+ parameters",
);
}
}
From 8ad15dea3f9ac9b0fcfad4a61a70aa47ecc4d938 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Sun, 3 Jun 2018 19:57:49 +0200
Subject: [PATCH 12/12] turn run-make test into a run-make-fulldeps test
---
.../panic-impl-transitive/Makefile | 0
.../panic-impl-transitive/panic-impl-consumer.rs | 0
.../panic-impl-transitive/panic-impl-provider.rs | 0
3 files changed, 0 insertions(+), 0 deletions(-)
rename src/test/{run-make => run-make-fulldeps}/panic-impl-transitive/Makefile (100%)
rename src/test/{run-make => run-make-fulldeps}/panic-impl-transitive/panic-impl-consumer.rs (100%)
rename src/test/{run-make => run-make-fulldeps}/panic-impl-transitive/panic-impl-provider.rs (100%)
diff --git a/src/test/run-make/panic-impl-transitive/Makefile b/src/test/run-make-fulldeps/panic-impl-transitive/Makefile
similarity index 100%
rename from src/test/run-make/panic-impl-transitive/Makefile
rename to src/test/run-make-fulldeps/panic-impl-transitive/Makefile
diff --git a/src/test/run-make/panic-impl-transitive/panic-impl-consumer.rs b/src/test/run-make-fulldeps/panic-impl-transitive/panic-impl-consumer.rs
similarity index 100%
rename from src/test/run-make/panic-impl-transitive/panic-impl-consumer.rs
rename to src/test/run-make-fulldeps/panic-impl-transitive/panic-impl-consumer.rs
diff --git a/src/test/run-make/panic-impl-transitive/panic-impl-provider.rs b/src/test/run-make-fulldeps/panic-impl-transitive/panic-impl-provider.rs
similarity index 100%
rename from src/test/run-make/panic-impl-transitive/panic-impl-provider.rs
rename to src/test/run-make-fulldeps/panic-impl-transitive/panic-impl-provider.rs