diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs index 8efe3eb868b94..dacd8f7c12cfd 100644 --- a/compiler/rustc_const_eval/src/const_eval/machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/machine.rs @@ -30,34 +30,25 @@ impl<'mir, 'tcx> InterpCx<'mir, 'tcx, CompileTimeInterpreter<'mir, 'tcx>> { &mut self, instance: ty::Instance<'tcx>, args: &[OpTy<'tcx>], - is_const_fn: bool, ) -> InterpResult<'tcx, Option>> { - // The list of functions we handle here must be in sync with - // `is_lang_special_const_fn` in `transform/check_consts/mod.rs`. + // All `#[rustc_do_not_const_check]` functions should be hooked here. let def_id = instance.def_id(); - if is_const_fn { - if Some(def_id) == self.tcx.lang_items().const_eval_select() { - // redirect to const_eval_select_ct - if let Some(const_eval_select) = self.tcx.lang_items().const_eval_select_ct() { - return Ok(Some( - ty::Instance::resolve( - *self.tcx, - ty::ParamEnv::reveal_all(), - const_eval_select, - instance.substs, - ) - .unwrap() - .unwrap(), - )); - } + if Some(def_id) == self.tcx.lang_items().const_eval_select() { + // redirect to const_eval_select_ct + if let Some(const_eval_select) = self.tcx.lang_items().const_eval_select_ct() { + return Ok(Some( + ty::Instance::resolve( + *self.tcx, + ty::ParamEnv::reveal_all(), + const_eval_select, + instance.substs, + ) + .unwrap() + .unwrap(), + )); } - return Ok(None); - } - - if Some(def_id) == self.tcx.lang_items().panic_fn() - || Some(def_id) == self.tcx.lang_items().panic_str() - || Some(def_id) == self.tcx.lang_items().panic_display() + } else if Some(def_id) == self.tcx.lang_items().panic_display() || Some(def_id) == self.tcx.lang_items().begin_panic_fn() { // &str or &&str @@ -274,31 +265,22 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir, // Only check non-glue functions if let ty::InstanceDef::Item(def) = instance.def { - let mut is_const_fn = true; - // Execution might have wandered off into other crates, so we cannot do a stability- // sensitive check here. But we can at least rule out functions that are not const // at all. if !ecx.tcx.is_const_fn_raw(def.did) { // allow calling functions marked with #[default_method_body_is_const]. if !ecx.tcx.has_attr(def.did, sym::default_method_body_is_const) { - is_const_fn = false; + // We certainly do *not* want to actually call the fn + // though, so be sure we return here. + throw_unsup_format!("calling non-const function `{}`", instance) } } - // Some functions we support even if they are non-const -- but avoid testing - // that for const fn! - // `const_eval_select` is a const fn because it must use const trait bounds. - if let Some(new_instance) = ecx.hook_special_const_fn(instance, args, is_const_fn)? { + if let Some(new_instance) = ecx.hook_special_const_fn(instance, args)? { // We call another const fn instead. return Self::find_mir_or_eval_fn(ecx, new_instance, _abi, args, _ret, _unwind); } - - if !is_const_fn { - // We certainly do *not* want to actually call the fn - // though, so be sure we return here. - throw_unsup_format!("calling non-const function `{}`", instance) - } } // This is a const fn. Call it. Ok(Some(ecx.load_mir(instance.def, None)?)) diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs index 85f37c813d85d..a3f685fb747c7 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs @@ -24,7 +24,7 @@ use std::ops::Deref; use super::ops::{self, NonConstOp, Status}; use super::qualifs::{self, CustomEq, HasMutInterior, NeedsDrop, NeedsNonConstDrop}; use super::resolver::FlowSensitiveAnalysis; -use super::{is_lang_panic_fn, is_lang_special_const_fn, ConstCx, Qualif}; +use super::{ConstCx, Qualif}; use crate::const_eval::is_unstable_const_fn; // We are using `MaybeMutBorrowedLocals` as a proxy for whether an item may have been mutated @@ -918,31 +918,27 @@ impl Visitor<'tcx> for Checker<'mir, 'tcx> { } // At this point, we are calling a function, `callee`, whose `DefId` is known... - if is_lang_special_const_fn(tcx, callee) { - // `begin_panic` and `panic_display` are generic functions that accept - // types other than str. Check to enforce that only str can be used in - // const-eval. - - // const-eval of the `begin_panic` fn assumes the argument is `&str` - if Some(callee) == tcx.lang_items().begin_panic_fn() { - match args[0].ty(&self.ccx.body.local_decls, tcx).kind() { - ty::Ref(_, ty, _) if ty.is_str() => (), - _ => self.check_op(ops::PanicNonStr), - } - } - // const-eval of the `panic_display` fn assumes the argument is `&&str` - if Some(callee) == tcx.lang_items().panic_display() { - match args[0].ty(&self.ccx.body.local_decls, tcx).kind() { - ty::Ref(_, ty, _) if matches!(ty.kind(), ty::Ref(_, ty, _) if ty.is_str()) => - {} - _ => self.check_op(ops::PanicNonStr), - } + // `begin_panic` and `panic_display` are generic functions that accept + // types other than str. Check to enforce that only str can be used in + // const-eval. + + // const-eval of the `begin_panic` fn assumes the argument is `&str` + if Some(callee) == tcx.lang_items().begin_panic_fn() { + match args[0].ty(&self.ccx.body.local_decls, tcx).kind() { + ty::Ref(_, ty, _) if ty.is_str() => return, + _ => self.check_op(ops::PanicNonStr), } + } - if is_lang_panic_fn(tcx, callee) { - // run stability check on non-panic special const fns. - return; + // const-eval of the `panic_display` fn assumes the argument is `&&str` + if Some(callee) == tcx.lang_items().panic_display() { + match args[0].ty(&self.ccx.body.local_decls, tcx).kind() { + ty::Ref(_, ty, _) if matches!(ty.kind(), ty::Ref(_, ty, _) if ty.is_str()) => + { + return; + } + _ => self.check_op(ops::PanicNonStr), } } diff --git a/compiler/rustc_const_eval/src/transform/check_consts/mod.rs b/compiler/rustc_const_eval/src/transform/check_consts/mod.rs index 58d0f1a3ad88e..dc44409d500a0 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/mod.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/mod.rs @@ -72,24 +72,6 @@ impl ConstCx<'mir, 'tcx> { } } -/// Returns `true` if this `DefId` points to one of the official `panic` lang items. -pub fn is_lang_panic_fn(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool { - Some(def_id) == tcx.lang_items().panic_fn() - || Some(def_id) == tcx.lang_items().panic_str() - || Some(def_id) == tcx.lang_items().panic_display() - || Some(def_id) == tcx.lang_items().begin_panic_fn() - || Some(def_id) == tcx.lang_items().panic_fmt() -} - -/// Returns `true` if this `DefId` points to one of the lang items that will be handled differently -/// in const_eval. -pub fn is_lang_special_const_fn(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool { - // We can allow calls to these functions because `hook_special_const_fn` in - // `const_eval/machine.rs` ensures the calls are handled specially. - // Keep in sync with what that function handles! - is_lang_panic_fn(tcx, def_id) || Some(def_id) == tcx.lang_items().const_eval_select() -} - pub fn rustc_allow_const_fn_unstable( tcx: TyCtxt<'tcx>, def_id: DefId, diff --git a/compiler/rustc_const_eval/src/transform/promote_consts.rs b/compiler/rustc_const_eval/src/transform/promote_consts.rs index ebcc8213c604b..67664d2ede1dd 100644 --- a/compiler/rustc_const_eval/src/transform/promote_consts.rs +++ b/compiler/rustc_const_eval/src/transform/promote_consts.rs @@ -26,7 +26,7 @@ use rustc_index::vec::{Idx, IndexVec}; use std::cell::Cell; use std::{cmp, iter, mem}; -use crate::transform::check_consts::{is_lang_special_const_fn, qualifs, ConstCx}; +use crate::transform::check_consts::{qualifs, ConstCx}; use crate::transform::MirPass; /// A `MirPass` for promotion. @@ -656,9 +656,7 @@ impl<'tcx> Validator<'_, 'tcx> { } let is_const_fn = match *fn_ty.kind() { - ty::FnDef(def_id, _) => { - self.tcx.is_const_fn_raw(def_id) || is_lang_special_const_fn(self.tcx, def_id) - } + ty::FnDef(def_id, _) => self.tcx.is_const_fn_raw(def_id), _ => false, }; if !is_const_fn { diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs index 9a4e54d826c5b..36496193d0370 100644 --- a/library/core/src/lib.rs +++ b/library/core/src/lib.rs @@ -107,6 +107,7 @@ #![feature(const_discriminant)] #![feature(const_float_bits_conv)] #![feature(const_float_classify)] +#![feature(const_fmt_arguments_new)] #![feature(const_heap)] #![feature(const_inherent_unchecked_arith)] #![feature(const_int_unchecked_arith)] diff --git a/library/core/src/panicking.rs b/library/core/src/panicking.rs index 087d2348ace08..29124c87e1bc5 100644 --- a/library/core/src/panicking.rs +++ b/library/core/src/panicking.rs @@ -34,13 +34,10 @@ use crate::panic::{Location, PanicInfo}; // never inline unless panic_immediate_abort to avoid code // bloat at the call sites as much as possible #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))] +#[cfg_attr(feature = "panic_immediate_abort", inline)] #[track_caller] #[lang = "panic"] // needed by codegen for panic on overflow and other `Assert` MIR terminators -pub fn panic(expr: &'static str) -> ! { - if cfg!(feature = "panic_immediate_abort") { - super::intrinsics::abort() - } - +pub const fn panic(expr: &'static str) -> ! { // Use Arguments::new_v1 instead of format_args!("{}", expr) to potentially // reduce size overhead. The format_args! macro uses str's Display trait to // write expr, which calls Formatter::pad, which must accommodate string @@ -52,15 +49,16 @@ pub fn panic(expr: &'static str) -> ! { #[inline] #[track_caller] -#[lang = "panic_str"] // needed for const-evaluated panics -pub fn panic_str(expr: &str) -> ! { - panic_fmt(format_args!("{}", expr)); +#[lang = "panic_str"] // needed for `non-fmt-panics` lint +pub const fn panic_str(expr: &str) -> ! { + panic_display(&expr); } #[inline] #[track_caller] #[lang = "panic_display"] // needed for const-evaluated panics -pub fn panic_display(x: &T) -> ! { +#[rustc_do_not_const_check] // hooked by const-eval +pub const fn panic_display(x: &T) -> ! { panic_fmt(format_args!("{}", *x)); } @@ -89,7 +87,8 @@ fn panic_bounds_check(index: usize, len: usize) -> ! { #[cfg_attr(feature = "panic_immediate_abort", inline)] #[track_caller] #[lang = "panic_fmt"] // needed for const-evaluated panics -pub fn panic_fmt(fmt: fmt::Arguments<'_>) -> ! { +#[rustc_do_not_const_check] // hooked by const-eval +pub const fn panic_fmt(fmt: fmt::Arguments<'_>) -> ! { if cfg!(feature = "panic_immediate_abort") { super::intrinsics::abort() } diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs index 335e0e072f3d9..0e7fb14439659 100644 --- a/library/std/src/lib.rs +++ b/library/std/src/lib.rs @@ -257,6 +257,7 @@ #![feature(const_cstr_unchecked)] #![feature(const_fn_floating_point_arithmetic)] #![feature(const_fn_fn_ptr_basics)] +#![feature(const_fn_trait_bound)] #![feature(const_format_args)] #![feature(const_io_structs)] #![feature(const_ip)] diff --git a/library/std/src/panicking.rs b/library/std/src/panicking.rs index 56646b72dd54f..437fcbb317601 100644 --- a/library/std/src/panicking.rs +++ b/library/std/src/panicking.rs @@ -512,7 +512,8 @@ pub fn begin_panic_handler(info: &PanicInfo<'_>) -> ! { #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))] #[cold] #[track_caller] -pub fn begin_panic(msg: M) -> ! { +#[rustc_do_not_const_check] // hooked by const-eval +pub const fn begin_panic(msg: M) -> ! { if cfg!(feature = "panic_immediate_abort") { intrinsics::abort() }