From c997c6d8224c544632ba86ab849721758330de48 Mon Sep 17 00:00:00 2001 From: "Celina G. Val" Date: Fri, 1 Dec 2023 16:20:35 -0800 Subject: [PATCH] Add more information to stable Instance - Retrieve `FnSig`. - Implement CrateDef for InstanceDef. - Add VTable index for Virtual instances. --- compiler/rustc_smir/src/rustc_smir/context.rs | 24 ++++++++++- .../rustc_smir/src/rustc_smir/convert/ty.rs | 4 +- compiler/stable_mir/src/compiler_interface.rs | 17 ++++++-- compiler/stable_mir/src/mir/mono.rs | 43 +++++++++++++++---- compiler/stable_mir/src/ty.rs | 38 ++++++++++++++-- tests/ui-fulldeps/stable-mir/check_defs.rs | 28 +++++++++++- 6 files changed, 134 insertions(+), 20 deletions(-) diff --git a/compiler/rustc_smir/src/rustc_smir/context.rs b/compiler/rustc_smir/src/rustc_smir/context.rs index 3449176f72937..0bd640ee1e3b0 100644 --- a/compiler/rustc_smir/src/rustc_smir/context.rs +++ b/compiler/rustc_smir/src/rustc_smir/context.rs @@ -3,6 +3,7 @@ //! This trait is currently the main interface between the Rust compiler, //! and the `stable_mir` crate. +use rustc_middle::ty; use rustc_middle::ty::print::{with_forced_trimmed_paths, with_no_trimmed_paths}; use rustc_middle::ty::{GenericPredicates, Instance, ParamEnv, ScalarInt, ValTree}; use rustc_span::def_id::LOCAL_CRATE; @@ -12,9 +13,9 @@ use stable_mir::mir::mono::{InstanceDef, StaticDef}; use stable_mir::mir::Body; use stable_mir::ty::{ AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, Const, FnDef, GenericArgs, LineInfo, - RigidTy, Span, TyKind, + PolyFnSig, RigidTy, Span, TyKind, }; -use stable_mir::{self, Crate, CrateItem, Error, Filename, ItemKind, Symbol}; +use stable_mir::{self, Crate, CrateItem, DefId, Error, Filename, ItemKind, Symbol}; use std::cell::RefCell; use crate::rustc_internal::{internal, RustcInternal}; @@ -39,6 +40,12 @@ impl<'tcx> Context for TablesWrapper<'tcx> { tables.tcx.instance_mir(rustc_middle::ty::InstanceDef::Item(def_id)).stable(&mut tables) } + fn has_body(&self, def: DefId) -> bool { + let tables = self.0.borrow(); + let def_id = tables[def]; + tables.tcx.is_mir_available(def_id) + } + fn all_trait_decls(&self) -> stable_mir::TraitDecls { let mut tables = self.0.borrow_mut(); tables @@ -195,6 +202,13 @@ impl<'tcx> Context for TablesWrapper<'tcx> { def.internal(&mut *tables).is_box() } + fn fn_sig(&self, def: FnDef, args: &GenericArgs) -> PolyFnSig { + let mut tables = self.0.borrow_mut(); + let def_id = def.0.internal(&mut *tables); + let sig = tables.tcx.fn_sig(def_id).instantiate(tables.tcx, args.internal(&mut *tables)); + sig.stable(&mut *tables) + } + fn eval_target_usize(&self, cnst: &Const) -> Result { let mut tables = self.0.borrow_mut(); let mir_const = cnst.internal(&mut *tables); @@ -266,6 +280,12 @@ impl<'tcx> Context for TablesWrapper<'tcx> { tables.tcx.symbol_name(instance).name.to_string() } + fn is_empty_drop_shim(&self, def: InstanceDef) -> bool { + let tables = self.0.borrow_mut(); + let instance = tables.instances[def]; + matches!(instance.def, ty::InstanceDef::DropGlue(_, None)) + } + fn mono_instance(&self, item: stable_mir::CrateItem) -> stable_mir::mir::mono::Instance { let mut tables = self.0.borrow_mut(); let def_id = tables[item.0]; diff --git a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs index 32ee928ddd406..f837f28e11ed2 100644 --- a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs +++ b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs @@ -777,7 +777,9 @@ impl<'tcx> Stable<'tcx> for ty::Instance<'tcx> { let kind = match self.def { ty::InstanceDef::Item(..) => stable_mir::mir::mono::InstanceKind::Item, ty::InstanceDef::Intrinsic(..) => stable_mir::mir::mono::InstanceKind::Intrinsic, - ty::InstanceDef::Virtual(..) => stable_mir::mir::mono::InstanceKind::Virtual, + ty::InstanceDef::Virtual(_def_id, idx) => { + stable_mir::mir::mono::InstanceKind::Virtual { idx } + } ty::InstanceDef::VTableShim(..) | ty::InstanceDef::ReifyShim(..) | ty::InstanceDef::FnPtrAddrShim(..) diff --git a/compiler/stable_mir/src/compiler_interface.rs b/compiler/stable_mir/src/compiler_interface.rs index 827418a643259..daf4465963edd 100644 --- a/compiler/stable_mir/src/compiler_interface.rs +++ b/compiler/stable_mir/src/compiler_interface.rs @@ -10,8 +10,8 @@ use crate::mir::mono::{Instance, InstanceDef, StaticDef}; use crate::mir::Body; use crate::ty::{ AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, Const, FnDef, GenericArgs, - GenericPredicates, Generics, ImplDef, ImplTrait, LineInfo, RigidTy, Span, TraitDecl, TraitDef, - Ty, TyKind, + GenericPredicates, Generics, ImplDef, ImplTrait, LineInfo, PolyFnSig, RigidTy, Span, TraitDecl, + TraitDef, Ty, TyKind, }; use crate::{ mir, Crate, CrateItem, CrateItems, DefId, Error, Filename, ImplTraitDecls, ItemKind, Symbol, @@ -24,7 +24,11 @@ pub trait Context { fn entry_fn(&self) -> Option; /// Retrieve all items of the local crate that have a MIR associated with them. fn all_local_items(&self) -> CrateItems; + /// Retrieve the body of a function. + /// This function will panic if the body is not available. fn mir_body(&self, item: DefId) -> mir::Body; + /// Check whether the body of a function is available. + fn has_body(&self, item: DefId) -> bool; fn all_trait_decls(&self) -> TraitDecls; fn trait_decl(&self, trait_def: &TraitDef) -> TraitDecl; fn all_trait_impls(&self) -> ImplTraitDecls; @@ -64,6 +68,9 @@ pub trait Context { /// Returns if the ADT is a box. fn adt_is_box(&self, def: AdtDef) -> bool; + /// Retrieve the function signature for the given generic arguments. + fn fn_sig(&self, def: FnDef, args: &GenericArgs) -> PolyFnSig; + /// Evaluate constant as a target usize. fn eval_target_usize(&self, cnst: &Const) -> Result; @@ -85,8 +92,7 @@ pub trait Context { /// Obtain the representation of a type. fn ty_kind(&self, ty: Ty) -> TyKind; - /// Get the body of an Instance. - /// FIXME: Monomorphize the body. + /// Get the body of an Instance which is already monomorphized. fn instance_body(&self, instance: InstanceDef) -> Option; /// Get the instance type with generic substitutions applied and lifetimes erased. @@ -98,6 +104,9 @@ pub trait Context { /// Get the instance mangled name. fn instance_mangled_name(&self, instance: InstanceDef) -> Symbol; + /// Check if this is an empty DropGlue shim. + fn is_empty_drop_shim(&self, def: InstanceDef) -> bool; + /// Convert a non-generic crate item into an instance. /// This function will panic if the item is generic. fn mono_instance(&self, item: CrateItem) -> Instance; diff --git a/compiler/stable_mir/src/mir/mono.rs b/compiler/stable_mir/src/mir/mono.rs index 9f9af5d630904..10270c82e6323 100644 --- a/compiler/stable_mir/src/mir/mono.rs +++ b/compiler/stable_mir/src/mir/mono.rs @@ -1,6 +1,6 @@ use crate::crate_def::CrateDef; use crate::mir::Body; -use crate::ty::{Allocation, ClosureDef, ClosureKind, FnDef, GenericArgs, IndexedVal, Ty}; +use crate::ty::{Allocation, ClosureDef, ClosureKind, FnDef, FnSig, GenericArgs, IndexedVal, Ty}; use crate::{with, CrateItem, DefId, Error, ItemKind, Opaque, Symbol}; use std::fmt::{Debug, Formatter}; @@ -27,7 +27,8 @@ pub enum InstanceKind { /// A compiler intrinsic function. Intrinsic, /// A virtual function definition stored in a VTable. - Virtual, + /// The `idx` field indicates the position in the VTable for this instance. + Virtual { idx: usize }, /// A compiler generated shim. Shim, } @@ -106,6 +107,24 @@ impl Instance { }) }) } + + /// Get this function signature with all types already instantiated. + pub fn fn_sig(&self) -> FnSig { + self.ty().kind().fn_sig().unwrap().skip_binder() + } + + /// Check whether this instance is an empty shim. + /// + /// Allow users to check if this shim can be ignored when called directly. + /// + /// We have decided not to export different types of Shims to StableMIR users, however, this + /// is a query that can be very helpful for users when processing DropGlue. + /// + /// When generating code for a Drop terminator, users can ignore an empty drop glue. + /// These shims are only needed to generate a valid Drop call done via VTable. + pub fn is_empty_shim(&self) -> bool { + self.kind == InstanceKind::Shim && with(|cx| cx.is_empty_drop_shim(self.def)) + } } impl Debug for Instance { @@ -124,8 +143,6 @@ impl TryFrom for Instance { fn try_from(item: CrateItem) -> Result { with(|context| { - // FIXME(celinval): - // - Return `Err` if instance does not have a body. if !context.requires_monomorphization(item.0) { Ok(context.mono_instance(item)) } else { @@ -141,11 +158,13 @@ impl TryFrom for CrateItem { type Error = crate::Error; fn try_from(value: Instance) -> Result { - if value.kind == InstanceKind::Item { - Ok(CrateItem(with(|context| context.instance_def_id(value.def)))) - } else { - Err(Error::new(format!("Item kind `{:?}` cannot be converted", value.kind))) - } + with(|context| { + if value.kind == InstanceKind::Item && context.has_body(value.def.def_id()) { + Ok(CrateItem(context.instance_def_id(value.def))) + } else { + Err(Error::new(format!("Item kind `{:?}` cannot be converted", value.kind))) + } + }) } } @@ -170,6 +189,12 @@ impl From for CrateItem { #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)] pub struct InstanceDef(usize); +impl CrateDef for InstanceDef { + fn def_id(&self) -> DefId { + with(|context| context.instance_def_id(*self)) + } +} + crate_def! { /// Holds information about a static variable definition. pub StaticDef; diff --git a/compiler/stable_mir/src/ty.rs b/compiler/stable_mir/src/ty.rs index 80558657debe3..6c4fb4a775352 100644 --- a/compiler/stable_mir/src/ty.rs +++ b/compiler/stable_mir/src/ty.rs @@ -168,7 +168,11 @@ impl TyKind { } pub fn is_unit(&self) -> bool { - matches!(self, TyKind::RigidTy(RigidTy::Tuple(data)) if data.len() == 0) + matches!(self, TyKind::RigidTy(RigidTy::Tuple(data)) if data.is_empty()) + } + + pub fn is_bool(&self) -> bool { + matches!(self, TyKind::RigidTy(RigidTy::Bool)) } pub fn is_trait(&self) -> bool { @@ -187,6 +191,14 @@ impl TyKind { matches!(self, TyKind::RigidTy(RigidTy::Adt(def, _)) if def.kind() == AdtKind::Union) } + pub fn is_fn(&self) -> bool { + matches!(self, TyKind::RigidTy(RigidTy::FnDef(..))) + } + + pub fn is_fn_ptr(&self) -> bool { + matches!(self, TyKind::RigidTy(RigidTy::FnPtr(..))) + } + pub fn trait_principal(&self) -> Option> { if let TyKind::RigidTy(RigidTy::Dynamic(predicates, _, _)) = self { if let Some(Binder { value: ExistentialPredicate::Trait(trait_ref), bound_vars }) = @@ -227,6 +239,15 @@ impl TyKind { _ => None, } } + + /// Get the function signature for function like types (Fn, FnPtr, Closure, Coroutine) + pub fn fn_sig(&self) -> Option { + match self { + TyKind::RigidTy(RigidTy::FnDef(def, args)) => Some(with(|cx| cx.fn_sig(*def, args))), + TyKind::RigidTy(RigidTy::FnPtr(sig)) => Some(sig.clone()), + _ => None, + } + } } pub struct TypeAndMut { @@ -307,8 +328,9 @@ crate_def! { } impl FnDef { - pub fn body(&self) -> Body { - with(|ctx| ctx.mir_body(self.0)) + // Get the function body if available. + pub fn body(&self) -> Option { + with(|ctx| ctx.has_body(self.0).then(|| ctx.mir_body(self.0))) } } @@ -488,6 +510,16 @@ pub struct FnSig { pub abi: Abi, } +impl FnSig { + pub fn output(&self) -> Ty { + self.inputs_and_output[self.inputs_and_output.len() - 1] + } + + pub fn inputs(&self) -> &[Ty] { + &self.inputs_and_output[..self.inputs_and_output.len() - 1] + } +} + #[derive(Clone, PartialEq, Eq, Debug)] pub enum Abi { Rust, diff --git a/tests/ui-fulldeps/stable-mir/check_defs.rs b/tests/ui-fulldeps/stable-mir/check_defs.rs index bbb4959628888..d311be5982d2d 100644 --- a/tests/ui-fulldeps/stable-mir/check_defs.rs +++ b/tests/ui-fulldeps/stable-mir/check_defs.rs @@ -18,10 +18,11 @@ extern crate rustc_driver; extern crate rustc_interface; extern crate stable_mir; +use std::assert_matches::assert_matches; use mir::{mono::Instance, TerminatorKind::*}; use rustc_middle::ty::TyCtxt; use rustc_smir::rustc_internal; -use stable_mir::ty::{RigidTy, TyKind}; +use stable_mir::ty::{RigidTy, TyKind, Ty, UintTy}; use stable_mir::*; use std::io::Write; use std::ops::ControlFlow; @@ -39,6 +40,7 @@ fn test_stable_mir(_tcx: TyCtxt<'_>) -> ControlFlow<()> { assert_eq!(instances.len(), 2); test_fn(instances[0], "from_u32", "std::char::from_u32", "core"); test_fn(instances[1], "Vec::::new", "std::vec::Vec::::new", "alloc"); + test_vec_new(instances[1]); ControlFlow::Continue(()) } @@ -56,6 +58,30 @@ fn test_fn(instance: Instance, expected_trimmed: &str, expected_qualified: &str, assert_eq!(&item.krate().name, krate); } +fn extract_elem_ty(ty: Ty) -> Ty { + match ty.kind() { + TyKind::RigidTy(RigidTy::Adt(_, args)) => { + *args.0[0].expect_ty() + } + _ => unreachable!("Expected Vec ADT, but found: {ty:?}") + } +} + +/// Check signature and type of `Vec::::new` and its generic version. +fn test_vec_new(instance: mir::mono::Instance) { + let sig = instance.fn_sig(); + assert_matches!(sig.inputs(), &[]); + let elem_ty = extract_elem_ty(sig.output()); + assert_matches!(elem_ty.kind(), TyKind::RigidTy(RigidTy::Uint(UintTy::U8))); + + // Get the signature for Vec::::new. + let item = CrateItem::try_from(instance).unwrap(); + let ty = item.ty(); + let gen_sig = ty.kind().fn_sig().unwrap().skip_binder(); + let gen_ty = extract_elem_ty(gen_sig.output()); + assert_matches!(gen_ty.kind(), TyKind::Param(_)); +} + /// Inspect the instance body fn get_instances(body: mir::Body) -> Vec { body.blocks.iter().filter_map(|bb| {