Merging upstream version 1.70.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

11 files changed, 384 insertions, 58 deletions

diff --git a/compiler/rustc_smir/Cargo.toml b/compiler/rustc_smir/Cargo.toml
index 5e0d1f369..fb97ee5be 100644
--- a/compiler/rustc_smir/Cargo.toml
+++ b/compiler/rustc_smir/Cargo.toml
@@ -4,25 +4,12 @@ version = "0.0.0"
 edition = "2021"
 
 [dependencies]
-rustc_borrowck = { path = "../rustc_borrowck", optional = true }
-rustc_driver = { path = "../rustc_driver", optional = true }
-rustc_hir = { path = "../rustc_hir", optional = true }
-rustc_interface = { path = "../rustc_interface", optional = true }
 rustc_middle = { path = "../rustc_middle", optional = true }
-rustc_mir_dataflow = { path = "../rustc_mir_dataflow", optional = true }
-rustc_mir_transform = { path = "../rustc_mir_transform", optional = true }
-rustc_serialize = { path = "../rustc_serialize", optional = true }
-rustc_trait_selection = { path = "../rustc_trait_selection", optional = true }
+rustc_span = { path = "../rustc_span", optional = true }
+tracing = "0.1"
 
 [features]
 default = [
-    "rustc_borrowck",
-    "rustc_driver",
-    "rustc_hir",
-    "rustc_interface",
     "rustc_middle",
-    "rustc_mir_dataflow",
-    "rustc_mir_transform",
-    "rustc_serialize",
-    "rustc_trait_selection",
+    "rustc_span",
 ]
diff --git a/compiler/rustc_smir/README.md b/compiler/rustc_smir/README.md
index ae49098dd..31dee955f 100644
--- a/compiler/rustc_smir/README.md
+++ b/compiler/rustc_smir/README.md
@@ -73,3 +73,40 @@ git subtree pull --prefix=compiler/rustc_smir https://github.com/rust-lang/proje
 Note: only ever sync to rustc from the project-stable-mir's `smir` branch. Do not sync with your own forks.
 
 Then open a PR against rustc just like a regular PR.
+
+## Stable MIR Design
+
+The stable-mir will follow a similar approach to proc-macro2. It’s
+implementation will eventually be broken down into two main crates:
+
+- `stable_mir`: Public crate, to be published on crates.io, which will contain
+the stable data structure as well as proxy APIs to make calls to the
+compiler.
+- `rustc_smir`: The compiler crate that will translate from internal MIR to
+SMIR. This crate will also implement APIs that will be invoked by
+stable-mir to query the compiler for more information.
+
+This will help tools to communicate with the rust compiler via stable APIs. Tools will depend on
+`stable_mir` crate, which will invoke the compiler using APIs defined in `rustc_smir`. I.e.:
+
+```
+    ┌──────────────────────────────────┐           ┌──────────────────────────────────┐
+    │   External Tool     ┌──────────┐ │           │ ┌──────────┐   Rust Compiler     │
+    │                     │          │ │           │ │          │                     │
+    │                     │stable_mir| │           │ │rustc_smir│                     │
+    │                     │          │ ├──────────►| │          │                     │
+    │                     │          │ │◄──────────┤ │          │                     │
+    │                     │          │ │           │ │          │                     │
+    │                     │          │ │           │ │          │                     │
+    │                     └──────────┘ │           │ └──────────┘                     │
+    └──────────────────────────────────┘           └──────────────────────────────────┘
+```
+
+More details can be found here:
+https://hackmd.io/XhnYHKKuR6-LChhobvlT-g?view
+
+For now, the code for these two crates are in separate modules of this crate.
+The modules have the same name for simplicity. We also have a third module,
+`rustc_internal` which will expose APIs and definitions that allow users to
+gather information from internal MIR constructs that haven't been exposed in
+the `stable_mir` module.
diff --git a/compiler/rustc_smir/rust-toolchain.toml b/compiler/rustc_smir/rust-toolchain.toml
index 7b696fc1f..157dfd620 100644
--- a/compiler/rustc_smir/rust-toolchain.toml
+++ b/compiler/rustc_smir/rust-toolchain.toml
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2022-06-01"
+channel = "nightly-2023-02-28"
 components = [ "rustfmt", "rustc-dev" ]
diff --git a/compiler/rustc_smir/src/lib.rs b/compiler/rustc_smir/src/lib.rs
index 3e93c6bba..54d474db0 100644
--- a/compiler/rustc_smir/src/lib.rs
+++ b/compiler/rustc_smir/src/lib.rs
@@ -11,9 +11,9 @@
     test(attr(allow(unused_variables), deny(warnings)))
 )]
 #![cfg_attr(not(feature = "default"), feature(rustc_private))]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 
-pub mod mir;
+pub mod rustc_internal;
+pub mod stable_mir;
 
-pub mod very_unstable;
+// Make this module private for now since external users should not call these directly.
+mod rustc_smir;
diff --git a/compiler/rustc_smir/src/mir.rs b/compiler/rustc_smir/src/mir.rs
deleted file mode 100644
index 887e65729..000000000
--- a/compiler/rustc_smir/src/mir.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-pub use crate::very_unstable::hir::ImplicitSelfKind;
-pub use crate::very_unstable::middle::mir::{
-    visit::MutVisitor, AggregateKind, AssertKind, BasicBlock, BasicBlockData, BinOp, BindingForm,
-    BlockTailInfo, Body, BorrowKind, CastKind, ClearCrossCrate, Constant, ConstantKind,
-    CopyNonOverlapping, Coverage, FakeReadCause, Field, GeneratorInfo, InlineAsmOperand, Local,
-    LocalDecl, LocalInfo, LocalKind, Location, MirPhase, MirSource, NullOp, Operand, Place,
-    PlaceRef, ProjectionElem, ProjectionKind, Promoted, RetagKind, Rvalue, Safety, SourceInfo,
-    SourceScope, SourceScopeData, SourceScopeLocalData, Statement, StatementKind, UnOp,
-    UserTypeProjection, UserTypeProjections, VarBindingForm, VarDebugInfo, VarDebugInfoContents,
-};
diff --git a/compiler/rustc_smir/src/rustc_internal/mod.rs b/compiler/rustc_smir/src/rustc_internal/mod.rs
new file mode 100644
index 000000000..5998c8b65
--- /dev/null
+++ b/compiler/rustc_smir/src/rustc_internal/mod.rs
@@ -0,0 +1,32 @@
+//! Module that implements the bridge between Stable MIR and internal compiler MIR.
+//!
+//! For that, we define APIs that will temporarily be public to 3P that exposes rustc internal APIs
+//! until stable MIR is complete.
+
+use std::sync::RwLock;
+
+use crate::stable_mir;
+pub use rustc_span::def_id::{CrateNum, DefId};
+
+static DEF_ID_MAP: RwLock<Vec<DefId>> = RwLock::new(Vec::new());
+
+pub fn item_def_id(item: &stable_mir::CrateItem) -> DefId {
+    DEF_ID_MAP.read().unwrap()[item.0]
+}
+
+pub fn crate_item(did: DefId) -> stable_mir::CrateItem {
+    // FIXME: this becomes inefficient when we have too many ids
+    let mut map = DEF_ID_MAP.write().unwrap();
+    for (i, &d) in map.iter().enumerate() {
+        if d == did {
+            return stable_mir::CrateItem(i);
+        }
+    }
+    let id = map.len();
+    map.push(did);
+    stable_mir::CrateItem(id)
+}
+
+pub fn crate_num(item: &stable_mir::Crate) -> CrateNum {
+    item.id.into()
+}
diff --git a/compiler/rustc_smir/src/rustc_smir/mod.rs b/compiler/rustc_smir/src/rustc_smir/mod.rs
new file mode 100644
index 000000000..4dad3c6bc
--- /dev/null
+++ b/compiler/rustc_smir/src/rustc_smir/mod.rs
@@ -0,0 +1,162 @@
+//! Module that implements what will become the rustc side of Stable MIR.
+//!
+//! This module is responsible for building Stable MIR components from internal components.
+//!
+//! This module is not intended to be invoked directly by users. It will eventually
+//! become the public API of rustc that will be invoked by the `stable_mir` crate.
+//!
+//! For now, we are developing everything inside `rustc`, thus, we keep this module private.
+
+use crate::{
+    rustc_internal::{crate_item, item_def_id},
+    stable_mir::{self},
+};
+use rustc_middle::ty::{tls::with, TyCtxt};
+use rustc_span::def_id::{CrateNum, LOCAL_CRATE};
+use tracing::debug;
+
+/// Get information about the local crate.
+pub fn local_crate() -> stable_mir::Crate {
+    with(|tcx| smir_crate(tcx, LOCAL_CRATE))
+}
+
+/// Retrieve a list of all external crates.
+pub fn external_crates() -> Vec<stable_mir::Crate> {
+    with(|tcx| tcx.crates(()).iter().map(|crate_num| smir_crate(tcx, *crate_num)).collect())
+}
+
+/// Find a crate with the given name.
+pub fn find_crate(name: &str) -> Option<stable_mir::Crate> {
+    with(|tcx| {
+        [LOCAL_CRATE].iter().chain(tcx.crates(()).iter()).find_map(|crate_num| {
+            let crate_name = tcx.crate_name(*crate_num).to_string();
+            (name == crate_name).then(|| smir_crate(tcx, *crate_num))
+        })
+    })
+}
+
+/// Retrieve all items of the local crate that have a MIR associated with them.
+pub fn all_local_items() -> stable_mir::CrateItems {
+    with(|tcx| tcx.mir_keys(()).iter().map(|item| crate_item(item.to_def_id())).collect())
+}
+
+pub fn entry_fn() -> Option<stable_mir::CrateItem> {
+    with(|tcx| Some(crate_item(tcx.entry_fn(())?.0)))
+}
+
+/// Build a stable mir crate from a given crate number.
+fn smir_crate(tcx: TyCtxt<'_>, crate_num: CrateNum) -> stable_mir::Crate {
+    let crate_name = tcx.crate_name(crate_num).to_string();
+    let is_local = crate_num == LOCAL_CRATE;
+    debug!(?crate_name, ?crate_num, "smir_crate");
+    stable_mir::Crate { id: crate_num.into(), name: crate_name, is_local }
+}
+
+pub fn mir_body(item: &stable_mir::CrateItem) -> stable_mir::mir::Body {
+    with(|tcx| {
+        let def_id = item_def_id(item);
+        let mir = tcx.optimized_mir(def_id);
+        stable_mir::mir::Body {
+            blocks: mir
+                .basic_blocks
+                .iter()
+                .map(|block| stable_mir::mir::BasicBlock {
+                    terminator: rustc_terminator_to_terminator(block.terminator()),
+                    statements: block.statements.iter().map(rustc_statement_to_statement).collect(),
+                })
+                .collect(),
+        }
+    })
+}
+
+fn rustc_statement_to_statement(
+    s: &rustc_middle::mir::Statement<'_>,
+) -> stable_mir::mir::Statement {
+    use rustc_middle::mir::StatementKind::*;
+    match &s.kind {
+        Assign(assign) => stable_mir::mir::Statement::Assign(
+            rustc_place_to_place(&assign.0),
+            rustc_rvalue_to_rvalue(&assign.1),
+        ),
+        FakeRead(_) => todo!(),
+        SetDiscriminant { .. } => todo!(),
+        Deinit(_) => todo!(),
+        StorageLive(_) => todo!(),
+        StorageDead(_) => todo!(),
+        Retag(_, _) => todo!(),
+        PlaceMention(_) => todo!(),
+        AscribeUserType(_, _) => todo!(),
+        Coverage(_) => todo!(),
+        Intrinsic(_) => todo!(),
+        ConstEvalCounter => todo!(),
+        Nop => stable_mir::mir::Statement::Nop,
+    }
+}
+
+fn rustc_rvalue_to_rvalue(rvalue: &rustc_middle::mir::Rvalue<'_>) -> stable_mir::mir::Operand {
+    use rustc_middle::mir::Rvalue::*;
+    match rvalue {
+        Use(op) => rustc_op_to_op(op),
+        Repeat(_, _) => todo!(),
+        Ref(_, _, _) => todo!(),
+        ThreadLocalRef(_) => todo!(),
+        AddressOf(_, _) => todo!(),
+        Len(_) => todo!(),
+        Cast(_, _, _) => todo!(),
+        BinaryOp(_, _) => todo!(),
+        CheckedBinaryOp(_, _) => todo!(),
+        NullaryOp(_, _) => todo!(),
+        UnaryOp(_, _) => todo!(),
+        Discriminant(_) => todo!(),
+        Aggregate(_, _) => todo!(),
+        ShallowInitBox(_, _) => todo!(),
+        CopyForDeref(_) => todo!(),
+    }
+}
+
+fn rustc_op_to_op(op: &rustc_middle::mir::Operand<'_>) -> stable_mir::mir::Operand {
+    use rustc_middle::mir::Operand::*;
+    match op {
+        Copy(place) => stable_mir::mir::Operand::Copy(rustc_place_to_place(place)),
+        Move(place) => stable_mir::mir::Operand::Move(rustc_place_to_place(place)),
+        Constant(c) => stable_mir::mir::Operand::Constant(c.to_string()),
+    }
+}
+
+fn rustc_place_to_place(place: &rustc_middle::mir::Place<'_>) -> stable_mir::mir::Place {
+    assert_eq!(&place.projection[..], &[]);
+    stable_mir::mir::Place { local: place.local.as_usize() }
+}
+
+fn rustc_terminator_to_terminator(
+    terminator: &rustc_middle::mir::Terminator<'_>,
+) -> stable_mir::mir::Terminator {
+    use rustc_middle::mir::TerminatorKind::*;
+    use stable_mir::mir::Terminator;
+    match &terminator.kind {
+        Goto { target } => Terminator::Goto { target: target.as_usize() },
+        SwitchInt { discr, targets } => Terminator::SwitchInt {
+            discr: rustc_op_to_op(discr),
+            targets: targets
+                .iter()
+                .map(|(value, target)| stable_mir::mir::SwitchTarget {
+                    value,
+                    target: target.as_usize(),
+                })
+                .collect(),
+            otherwise: targets.otherwise().as_usize(),
+        },
+        Resume => Terminator::Resume,
+        Terminate => Terminator::Abort,
+        Return => Terminator::Return,
+        Unreachable => Terminator::Unreachable,
+        Drop { .. } => todo!(),
+        Call { .. } => todo!(),
+        Assert { .. } => todo!(),
+        Yield { .. } => todo!(),
+        GeneratorDrop => todo!(),
+        FalseEdge { .. } => todo!(),
+        FalseUnwind { .. } => todo!(),
+        InlineAsm { .. } => todo!(),
+    }
+}
diff --git a/compiler/rustc_smir/src/stable_mir/mir.rs b/compiler/rustc_smir/src/stable_mir/mir.rs
new file mode 100644
index 000000000..a9dbc3463
--- /dev/null
+++ b/compiler/rustc_smir/src/stable_mir/mir.rs
@@ -0,0 +1,3 @@
+mod body;
+
+pub use body::*;
diff --git a/compiler/rustc_smir/src/stable_mir/mir/body.rs b/compiler/rustc_smir/src/stable_mir/mir/body.rs
new file mode 100644
index 000000000..c504065c9
--- /dev/null
+++ b/compiler/rustc_smir/src/stable_mir/mir/body.rs
@@ -0,0 +1,69 @@
+#[derive(Clone, Debug)]
+pub struct Body {
+    pub blocks: Vec<BasicBlock>,
+}
+
+#[derive(Clone, Debug)]
+pub struct BasicBlock {
+    pub statements: Vec<Statement>,
+    pub terminator: Terminator,
+}
+
+#[derive(Clone, Debug)]
+pub enum Terminator {
+    Goto {
+        target: usize,
+    },
+    SwitchInt {
+        discr: Operand,
+        targets: Vec<SwitchTarget>,
+        otherwise: usize,
+    },
+    Resume,
+    Abort,
+    Return,
+    Unreachable,
+    Drop {
+        place: Place,
+        target: usize,
+        unwind: Option<usize>,
+    },
+    Call {
+        func: Operand,
+        args: Vec<Operand>,
+        destination: Place,
+        target: Option<usize>,
+        cleanup: Option<usize>,
+    },
+    Assert {
+        cond: Operand,
+        expected: bool,
+        msg: String,
+        target: usize,
+        cleanup: Option<usize>,
+    },
+}
+
+#[derive(Clone, Debug)]
+pub enum Statement {
+    Assign(Place, Operand),
+    Nop,
+}
+
+#[derive(Clone, Debug)]
+pub enum Operand {
+    Copy(Place),
+    Move(Place),
+    Constant(String),
+}
+
+#[derive(Clone, Debug)]
+pub struct Place {
+    pub local: usize,
+}
+
+#[derive(Clone, Debug)]
+pub struct SwitchTarget {
+    pub value: u128,
+    pub target: usize,
+}
diff --git a/compiler/rustc_smir/src/stable_mir/mod.rs b/compiler/rustc_smir/src/stable_mir/mod.rs
new file mode 100644
index 000000000..1d2efb5ea
--- /dev/null
+++ b/compiler/rustc_smir/src/stable_mir/mod.rs
@@ -0,0 +1,73 @@
+//! Module that implements the public interface to the Stable MIR.
+//!
+//! This module shall contain all type definitions and APIs that we expect 3P tools to invoke to
+//! interact with the compiler.
+//!
+//! The goal is to eventually move this module to its own crate which shall be published on
+//! [crates.io](https://crates.io).
+//!
+//! ## Note:
+//!
+//! There shouldn't be any direct references to internal compiler constructs in this module.
+//! If you need an internal construct, consider using `rustc_internal` or `rustc_smir`.
+
+pub mod mir;
+
+/// Use String for now but we should replace it.
+pub type Symbol = String;
+
+/// The number that identifies a crate.
+pub type CrateNum = usize;
+
+/// A unique identification number for each item accessible for the current compilation unit.
+pub type DefId = usize;
+
+/// A list of crate items.
+pub type CrateItems = Vec<CrateItem>;
+
+/// Holds information about a crate.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct Crate {
+    pub(crate) id: CrateNum,
+    pub name: Symbol,
+    pub is_local: bool,
+}
+
+/// Holds information about an item in the crate.
+/// For now, it only stores the item DefId. Use functions inside `rustc_internal` module to
+/// use this item.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct CrateItem(pub(crate) DefId);
+
+impl CrateItem {
+    pub fn body(&self) -> mir::Body {
+        crate::rustc_smir::mir_body(self)
+    }
+}
+
+/// Return the function where execution starts if the current
+/// crate defines that. This is usually `main`, but could be
+/// `start` if the crate is a no-std crate.
+pub fn entry_fn() -> Option<CrateItem> {
+    crate::rustc_smir::entry_fn()
+}
+
+/// Access to the local crate.
+pub fn local_crate() -> Crate {
+    crate::rustc_smir::local_crate()
+}
+
+/// Try to find a crate with the given name.
+pub fn find_crate(name: &str) -> Option<Crate> {
+    crate::rustc_smir::find_crate(name)
+}
+
+/// Try to find a crate with the given name.
+pub fn external_crates() -> Vec<Crate> {
+    crate::rustc_smir::external_crates()
+}
+
+/// Retrieve all items in the local crate that have a MIR associated with them.
+pub fn all_local_items() -> CrateItems {
+    crate::rustc_smir::all_local_items()
+}
diff --git a/compiler/rustc_smir/src/very_unstable.rs b/compiler/rustc_smir/src/very_unstable.rs
deleted file mode 100644
index 12ba133db..000000000
--- a/compiler/rustc_smir/src/very_unstable.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-//! This module reexports various crates and modules from unstable rustc APIs.
-//! Add anything you need here and it will get slowly transferred to a stable API.
-//! Only use rustc_smir in your dependencies and use the reexports here instead of
-//! directly referring to the unstable crates.
-
-macro_rules! crates {
-    ($($rustc_name:ident -> $name:ident,)*) => {
-        $(
-            #[cfg(not(feature = "default"))]
-            pub extern crate $rustc_name as $name;
-            #[cfg(feature = "default")]
-            pub use $rustc_name as $name;
-        )*
-    }
-}
-
-crates! {
-    rustc_borrowck -> borrowck,
-    rustc_driver -> driver,
-    rustc_hir -> hir,
-    rustc_interface -> interface,
-    rustc_middle -> middle,
-    rustc_mir_dataflow -> dataflow,
-    rustc_mir_transform -> transform,
-    rustc_serialize -> serialize,
-    rustc_trait_selection -> trait_selection,
-}