diff --git a/compiler/rustc_smir/src/rustc_smir/builder.rs b/compiler/rustc_smir/src/rustc_smir/builder.rs index 0762016ef75b3..221224eed0170 100644 --- a/compiler/rustc_smir/src/rustc_smir/builder.rs +++ b/compiler/rustc_smir/src/rustc_smir/builder.rs @@ -4,9 +4,10 @@ //! monomorphic body using internal representation. //! After that, we convert the internal representation into a stable one. use crate::rustc_smir::{Stable, Tables}; +use rustc_hir::def::DefKind; use rustc_middle::mir; use rustc_middle::mir::visit::MutVisitor; -use rustc_middle::ty::{self, GenericArgsRef, Ty, TyCtxt}; +use rustc_middle::ty::{self, TyCtxt}; /// Builds a monomorphic body for a given instance. pub struct BodyBuilder<'tcx> { @@ -16,46 +17,43 @@ pub struct BodyBuilder<'tcx> { impl<'tcx> BodyBuilder<'tcx> { pub fn new(tcx: TyCtxt<'tcx>, instance: ty::Instance<'tcx>) -> Self { + let instance = match instance.def { + // To get the fallback body of an intrinsic, we need to convert it to an item. + ty::InstanceDef::Intrinsic(def_id) => ty::Instance::new(def_id, instance.args), + _ => instance, + }; BodyBuilder { tcx, instance } } /// Build a stable monomorphic body for a given instance based on the MIR body. /// - /// Note that we skip instantiation for static and constants. Trying to do so can cause ICE. - /// - /// We do monomorphize non-generic functions to eval unevaluated constants. + /// All constants are also evaluated. pub fn build(mut self, tables: &mut Tables<'tcx>) -> stable_mir::mir::Body { - let mut body = self.tcx.instance_mir(self.instance.def).clone(); - if self.tcx.def_kind(self.instance.def_id()).is_fn_like() || !self.instance.args.is_empty() + let body = tables.tcx.instance_mir(self.instance.def).clone(); + let mono_body = if !self.instance.args.is_empty() + // Without the `generic_const_exprs` feature gate, anon consts in signatures do not + // get generic parameters. Which is wrong, but also not a problem without + // generic_const_exprs + || self.tcx.def_kind(self.instance.def_id()) != DefKind::AnonConst { - self.visit_body(&mut body); - } - body.stable(tables) - } - - fn monomorphize(&self, value: T) -> T - where - T: ty::TypeFoldable>, - { - self.instance.instantiate_mir_and_normalize_erasing_regions( - self.tcx, - ty::ParamEnv::reveal_all(), - ty::EarlyBinder::bind(value), - ) + let mut mono_body = self.instance.instantiate_mir_and_normalize_erasing_regions( + tables.tcx, + ty::ParamEnv::reveal_all(), + ty::EarlyBinder::bind(body), + ); + self.visit_body(&mut mono_body); + mono_body + } else { + // Already monomorphic. + body + }; + mono_body.stable(tables) } } impl<'tcx> MutVisitor<'tcx> for BodyBuilder<'tcx> { - fn visit_ty_const(&mut self, ct: &mut ty::Const<'tcx>, _location: mir::Location) { - *ct = self.monomorphize(*ct); - } - - fn visit_ty(&mut self, ty: &mut Ty<'tcx>, _: mir::visit::TyContext) { - *ty = self.monomorphize(*ty); - } - fn visit_constant(&mut self, constant: &mut mir::ConstOperand<'tcx>, location: mir::Location) { - let const_ = self.monomorphize(constant.const_); + let const_ = constant.const_; let val = match const_.eval(self.tcx, ty::ParamEnv::reveal_all(), constant.span) { Ok(v) => v, Err(mir::interpret::ErrorHandled::Reported(..)) => return, @@ -68,10 +66,6 @@ impl<'tcx> MutVisitor<'tcx> for BodyBuilder<'tcx> { self.super_constant(constant, location); } - fn visit_args(&mut self, args: &mut GenericArgsRef<'tcx>, _: mir::Location) { - *args = self.monomorphize(*args); - } - fn tcx(&self) -> TyCtxt<'tcx> { self.tcx } diff --git a/compiler/stable_mir/src/mir/mono.rs b/compiler/stable_mir/src/mir/mono.rs index aafa89c03e000..a032a180fcfdd 100644 --- a/compiler/stable_mir/src/mir/mono.rs +++ b/compiler/stable_mir/src/mir/mono.rs @@ -41,13 +41,22 @@ impl Instance { with(|cx| cx.instance_args(self.def)) } - /// Get the body of an Instance. The body will be eagerly monomorphized. + /// Get the body of an Instance. + /// + /// The body will be eagerly monomorphized and all constants will already be evaluated. + /// + /// This method will return the intrinsic fallback body if one was defined. pub fn body(&self) -> Option { with(|context| context.instance_body(self.def)) } /// Check whether this instance has a body available. /// + /// For intrinsics with fallback body, this will return `true`. It is up to the user to decide + /// whether to specialize the intrinsic or to use its fallback body. + /// + /// For more information on fallback body, see . + /// /// This call is much cheaper than `instance.body().is_some()`, since it doesn't try to build /// the StableMIR body. pub fn has_body(&self) -> bool { diff --git a/tests/ui-fulldeps/stable-mir/check_intrinsics.rs b/tests/ui-fulldeps/stable-mir/check_intrinsics.rs new file mode 100644 index 0000000000000..171850b89bb5e --- /dev/null +++ b/tests/ui-fulldeps/stable-mir/check_intrinsics.rs @@ -0,0 +1,115 @@ +//@ run-pass +//! Test information regarding intrinsics and ensure we can retrieve the fallback body if it exists. +//! +//! This tests relies on the intrinsics implementation, and requires one intrinsic with and one +//! without a body. It doesn't matter which intrinsic is called here, and feel free to update that +//! if needed. + +//@ ignore-stage1 +//@ ignore-cross-compile +//@ ignore-remote +//@ ignore-windows-gnu mingw has troubles with linking https://github.com/rust-lang/rust/pull/116837 + +#![feature(rustc_private)] + +extern crate rustc_hir; +#[macro_use] +extern crate rustc_smir; +extern crate rustc_driver; +extern crate rustc_interface; +extern crate stable_mir; + +use rustc_smir::rustc_internal; +use stable_mir::mir::mono::{Instance, InstanceKind}; +use stable_mir::mir::visit::{Location, MirVisitor}; +use stable_mir::mir::{LocalDecl, Terminator, TerminatorKind}; +use stable_mir::ty::{RigidTy, TyKind}; +use std::collections::HashSet; +use std::convert::TryFrom; +use std::io::Write; +use std::ops::ControlFlow; + +/// This function tests that we can correctly get type information from binary operations. +fn test_intrinsics() -> ControlFlow<()> { + // Find items in the local crate. + let main_def = stable_mir::all_local_items()[0]; + let main_instance = Instance::try_from(main_def).unwrap(); + let main_body = main_instance.body().unwrap(); + let mut visitor = CallsVisitor { locals: main_body.locals(), calls: Default::default() }; + visitor.visit_body(&main_body); + + let calls = visitor.calls; + assert_eq!(calls.len(), 2, "Expected 2 calls, but found: {calls:?}"); + for intrinsic in &calls { + check_intrinsic(intrinsic) + } + + ControlFlow::Continue(()) +} + +/// This check is unfortunately tight to the implementation of intrinsics. +/// +/// We want to ensure that StableMIR can handle intrinsics with and without fallback body. +/// +/// If by any chance this test breaks because you changed how an intrinsic is implemented, please +/// update the test to invoke a different intrinsic. +fn check_intrinsic(intrinsic: &Instance) { + assert_eq!(intrinsic.kind, InstanceKind::Intrinsic); + let name = intrinsic.intrinsic_name().unwrap(); + if intrinsic.has_body() { + let Some(body) = intrinsic.body() else { unreachable!("Expected a body") }; + assert!(!body.blocks.is_empty()); + assert_eq!(&name, "likely"); + } else { + assert!(intrinsic.body().is_none()); + assert_eq!(&name, "size_of_val"); + } +} + +struct CallsVisitor<'a> { + locals: &'a [LocalDecl], + calls: HashSet, +} + +impl<'a> MirVisitor for CallsVisitor<'a> { + fn visit_terminator(&mut self, term: &Terminator, _loc: Location) { + match &term.kind { + TerminatorKind::Call { func, .. } => { + let TyKind::RigidTy(RigidTy::FnDef(def, args)) = + func.ty(self.locals).unwrap().kind() + else { + return; + }; + self.calls.insert(Instance::resolve(def, &args).unwrap()); + } + _ => {} + } + } +} + +/// This test will generate and analyze a dummy crate using the stable mir. +/// For that, it will first write the dummy crate into a file. +/// Then it will create a `StableMir` using custom arguments and then +/// it will run the compiler. +fn main() { + let path = "binop_input.rs"; + generate_input(&path).unwrap(); + let args = vec!["rustc".to_string(), "--crate-type=lib".to_string(), path.to_string()]; + run!(args, test_intrinsics).unwrap(); +} + +fn generate_input(path: &str) -> std::io::Result<()> { + let mut file = std::fs::File::create(path)?; + write!( + file, + r#" + #![feature(core_intrinsics)] + use std::intrinsics::*; + pub fn use_intrinsics(init: bool) -> bool {{ + let sz = unsafe {{ size_of_val("hi") }}; + likely(init && sz == 2) + }} + "# + )?; + Ok(()) +}