Rollup of 6 pull requests

.gitignore

@@ -21,6 +21,7 @@ Session.vim
 .project
 .favorites.json
 .settings/
+.vs/
 
 ## Tool
 .valgrindrc

Cargo.lock

@@ -4669,15 +4669,9 @@ dependencies = [
 name = "rustc_smir"
 version = "0.0.0"
 dependencies = [
- "rustc_borrowck",
- "rustc_driver",
- "rustc_hir",
- "rustc_interface",
  "rustc_middle",
- "rustc_mir_dataflow",
- "rustc_mir_transform",
- "rustc_serialize",
- "rustc_trait_selection",
+ "rustc_span",
+ "tracing",
 ]
 
 [[package]]

compiler/rustc_builtin_macros/src/test.rs

@@ -8,7 +8,7 @@ use rustc_errors::Applicability;
 use rustc_expand::base::*;
 use rustc_session::Session;
 use rustc_span::symbol::{sym, Ident, Symbol};
-use rustc_span::Span;
+use rustc_span::{FileNameDisplayPreference, Span};
 use std::iter;
 use thin_vec::{thin_vec, ThinVec};
 
@@ -231,6 +231,8 @@ pub fn expand_test_or_bench(
         &item.ident,
     ));
 
+    let location_info = get_location_info(cx, &item);
+
     let mut test_const = cx.item(
         sp,
         Ident::new(item.ident.name, sp),
@@ -280,6 +282,16 @@ pub fn expand_test_or_bench(
                                             cx.expr_none(sp)
                                         },
                                     ),
+                                    // source_file: <relative_path_of_source_file>
+                                    field("source_file", cx.expr_str(sp, location_info.0)),
+                                    // start_line: start line of the test fn identifier.
+                                    field("start_line", cx.expr_usize(sp, location_info.1)),
+                                    // start_col: start column of the test fn identifier.
+                                    field("start_col", cx.expr_usize(sp, location_info.2)),
+                                    // end_line: end line of the test fn identifier.
+                                    field("end_line", cx.expr_usize(sp, location_info.3)),
+                                    // end_col: end column of the test fn identifier.
+                                    field("end_col", cx.expr_usize(sp, location_info.4)),
                                     // compile_fail: true | false
                                     field("compile_fail", cx.expr_bool(sp, false)),
                                     // no_run: true | false
@@ -364,6 +376,19 @@ pub fn expand_test_or_bench(
     }
 }
 
+fn get_location_info(cx: &ExtCtxt<'_>, item: &ast::Item) -> (Symbol, usize, usize, usize, usize) {
+    let span = item.ident.span;
+    let (source_file, lo_line, lo_col, hi_line, hi_col) =
+        cx.sess.source_map().span_to_location_info(span);
+
+    let file_name = match source_file {
+        Some(sf) => sf.name.display(FileNameDisplayPreference::Local).to_string(),
+        None => "no-location".to_string(),
+    };
+
+    (Symbol::intern(&file_name), lo_line, lo_col, hi_line, hi_col)
+}
+
 fn item_path(mod_path: &[Ident], item_ident: &Ident) -> String {
     mod_path
         .iter()

compiler/rustc_hir_analysis/locales/en-US.ftl

@@ -163,3 +163,10 @@ hir_analysis_pass_to_variadic_function = can't pass `{$ty}` to variadic function
     .help = cast the value to `{$cast_ty}`
 
 hir_analysis_cast_thin_pointer_to_fat_pointer = cannot cast thin pointer `{$expr_ty}` to fat pointer `{$cast_ty}`
+
+hir_analysis_invalid_union_field =
+    field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be used in a union
+    .note = union fields must not have drop side-effects, which is currently enforced via either `Copy` or `ManuallyDrop<...>`
+
+hir_analysis_invalid_union_field_sugg =
+    wrap the field type in `ManuallyDrop<...>`

compiler/rustc_hir_analysis/src/check/check.rs

@@ -1,5 +1,5 @@
 use crate::check::intrinsicck::InlineAsmCtxt;
-use crate::errors::LinkageType;
+use crate::errors::{self, LinkageType};
 
 use super::compare_impl_item::check_type_bounds;
 use super::compare_impl_item::{compare_impl_method, compare_impl_ty};
@@ -114,9 +114,11 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
                     allowed_union_field(*elem, tcx, param_env)
                 }
                 _ => {
-                    // Fallback case: allow `ManuallyDrop` and things that are `Copy`.
+                    // Fallback case: allow `ManuallyDrop` and things that are `Copy`,
+                    // also no need to report an error if the type is unresolved.
                     ty.ty_adt_def().is_some_and(|adt_def| adt_def.is_manually_drop())
                         || ty.is_copy_modulo_regions(tcx, param_env)
+                        || ty.references_error()
                 }
             }
         }
@@ -131,26 +133,14 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
                     Some(Node::Field(field)) => (field.span, field.ty.span),
                     _ => unreachable!("mir field has to correspond to hir field"),
                 };
-                struct_span_err!(
-                    tcx.sess,
+                tcx.sess.emit_err(errors::InvalidUnionField {
                     field_span,
-                    E0740,
-                    "unions cannot contain fields that may need dropping"
-                )
-                .note(
-                    "a type is guaranteed not to need dropping \
-                    when it implements `Copy`, or when it is the special `ManuallyDrop<_>` type",
-                )
-                .multipart_suggestion_verbose(
-                    "when the type does not implement `Copy`, \
-                    wrap it inside a `ManuallyDrop<_>` and ensure it is manually dropped",
-                    vec![
-                        (ty_span.shrink_to_lo(), "std::mem::ManuallyDrop<".into()),
-                        (ty_span.shrink_to_hi(), ">".into()),
-                    ],
-                    Applicability::MaybeIncorrect,
-                )
-                .emit();
+                    sugg: errors::InvalidUnionFieldSuggestion {
+                        lo: ty_span.shrink_to_lo(),
+                        hi: ty_span.shrink_to_hi(),
+                    },
+                    note: (),
+                });
                 return false;
             } else if field_ty.needs_drop(tcx, param_env) {
                 // This should never happen. But we can get here e.g. in case of name resolution errors.

compiler/rustc_hir_analysis/src/errors.rs

@@ -5,7 +5,7 @@ use rustc_errors::{
     error_code, Applicability, DiagnosticBuilder, ErrorGuaranteed, Handler, IntoDiagnostic,
     MultiSpan,
 };
-use rustc_macros::Diagnostic;
+use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::{symbol::Ident, Span, Symbol};
 
@@ -430,3 +430,23 @@ pub(crate) struct CastThinPointerToFatPointer<'tcx> {
     pub expr_ty: Ty<'tcx>,
     pub cast_ty: String,
 }
+
+#[derive(Diagnostic)]
+#[diag(hir_analysis_invalid_union_field, code = "E0740")]
+pub(crate) struct InvalidUnionField {
+    #[primary_span]
+    pub field_span: Span,
+    #[subdiagnostic]
+    pub sugg: InvalidUnionFieldSuggestion,
+    #[note]
+    pub note: (),
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(hir_analysis_invalid_union_field_sugg, applicability = "machine-applicable")]
+pub(crate) struct InvalidUnionFieldSuggestion {
+    #[suggestion_part(code = "std::mem::ManuallyDrop<")]
+    pub lo: Span,
+    #[suggestion_part(code = ">")]
+    pub hi: Span,
+}

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",
 ]

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.

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" ]

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;

compiler/rustc_smir/src/rustc_internal/mod.rs

@@ -0,0 +1,15 @@
+//! 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 crate::stable_mir;
+pub use rustc_span::def_id::{CrateNum, DefId};
+
+pub fn item_def_id(item: &stable_mir::CrateItem) -> DefId {
+    item.0
+}
+
+pub fn crate_num(item: &stable_mir::Crate) -> CrateNum {
+    item.id.into()
+}

compiler/rustc_smir/src/rustc_smir/mod.rs

@@ -0,0 +1,48 @@
+//! 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::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| stable_mir::CrateItem(item.to_def_id())).collect()
+    })
+}
+
+/// 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 }
+}