Merging upstream version 1.74.1+dfsg1.

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

1 files changed, 123 insertions, 30 deletions

diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs
index 4cf358732..5fa65f33c 100644
--- a/compiler/rustc_hir_analysis/src/check/mod.rs
+++ b/compiler/rustc_hir_analysis/src/check/mod.rs
@@ -73,23 +73,31 @@ pub mod wfcheck;
 
 pub use check::check_abi;
 
+use std::num::NonZeroU32;
+
 use check::check_mod_item_types;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{pluralize, struct_span_err, Diagnostic, DiagnosticBuilder};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::Visitor;
 use rustc_index::bit_set::BitSet;
+use rustc_infer::infer::error_reporting::ObligationCauseExt as _;
+use rustc_infer::infer::outlives::env::OutlivesEnvironment;
+use rustc_infer::infer::{self, TyCtxtInferExt as _};
+use rustc_infer::traits::ObligationCause;
 use rustc_middle::query::Providers;
+use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::ty::{GenericArgs, GenericArgsRef};
 use rustc_session::parse::feature_err;
 use rustc_span::source_map::DUMMY_SP;
 use rustc_span::symbol::{kw, Ident};
-use rustc_span::{self, BytePos, Span, Symbol};
+use rustc_span::{self, def_id::CRATE_DEF_ID, BytePos, Span, Symbol};
 use rustc_target::abi::VariantIdx;
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits::error_reporting::suggestions::ReturnsVisitor;
-use std::num::NonZeroU32;
+use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
+use rustc_trait_selection::traits::ObligationCtxt;
 
 use crate::errors;
 use crate::require_c_abi_if_c_variadic;
@@ -289,6 +297,7 @@ fn default_body_is_unstable(
         &tcx.sess.parse_sess,
         feature,
         rustc_feature::GateIssue::Library(issue),
+        false,
     );
 
     err.emit();
@@ -320,41 +329,52 @@ fn bounds_from_generic_predicates<'tcx>(
             _ => {}
         }
     }
-    let generics = if types.is_empty() {
-        "".to_string()
-    } else {
-        format!(
-            "<{}>",
-            types
-                .keys()
-                .filter_map(|t| match t.kind() {
-                    ty::Param(_) => Some(t.to_string()),
-                    // Avoid suggesting the following:
-                    // fn foo<T, <T as Trait>::Bar>(_: T) where T: Trait, <T as Trait>::Bar: Other {}
-                    _ => None,
-                })
-                .collect::<Vec<_>>()
-                .join(", ")
-        )
-    };
+
     let mut where_clauses = vec![];
+    let mut types_str = vec![];
     for (ty, bounds) in types {
-        where_clauses
-            .extend(bounds.into_iter().map(|bound| format!("{}: {}", ty, tcx.def_path_str(bound))));
-    }
-    for projection in &projections {
-        let p = projection.skip_binder();
-        // FIXME: this is not currently supported syntax, we should be looking at the `types` and
-        // insert the associated types where they correspond, but for now let's be "lazy" and
-        // propose this instead of the following valid resugaring:
-        // `T: Trait, Trait::Assoc = K` → `T: Trait<Assoc = K>`
-        where_clauses.push(format!("{} = {}", tcx.def_path_str(p.projection_ty.def_id), p.term));
+        if let ty::Param(_) = ty.kind() {
+            let mut bounds_str = vec![];
+            for bound in bounds {
+                let mut projections_str = vec![];
+                for projection in &projections {
+                    let p = projection.skip_binder();
+                    let alias_ty = p.projection_ty;
+                    if bound == tcx.parent(alias_ty.def_id) && alias_ty.self_ty() == ty {
+                        let name = tcx.item_name(alias_ty.def_id);
+                        projections_str.push(format!("{} = {}", name, p.term));
+                    }
+                }
+                let bound_def_path = tcx.def_path_str(bound);
+                if projections_str.is_empty() {
+                    where_clauses.push(format!("{}: {}", ty, bound_def_path));
+                } else {
+                    bounds_str.push(format!("{}<{}>", bound_def_path, projections_str.join(", ")));
+                }
+            }
+            if bounds_str.is_empty() {
+                types_str.push(ty.to_string());
+            } else {
+                types_str.push(format!("{}: {}", ty, bounds_str.join(" + ")));
+            }
+        } else {
+            // Avoid suggesting the following:
+            // fn foo<T, <T as Trait>::Bar>(_: T) where T: Trait, <T as Trait>::Bar: Other {}
+            where_clauses.extend(
+                bounds.into_iter().map(|bound| format!("{}: {}", ty, tcx.def_path_str(bound))),
+            );
+        }
     }
+
+    let generics =
+        if types_str.is_empty() { "".to_string() } else { format!("<{}>", types_str.join(", ")) };
+
     let where_clauses = if where_clauses.is_empty() {
-        String::new()
+        "".to_string()
     } else {
         format!(" where {}", where_clauses.join(", "))
     };
+
     (generics, where_clauses)
 }
 
@@ -545,3 +565,76 @@ fn bad_non_zero_sized_fields<'tcx>(
 pub fn potentially_plural_count(count: usize, word: &str) -> String {
     format!("{} {}{}", count, word, pluralize!(count))
 }
+
+pub fn check_function_signature<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    mut cause: ObligationCause<'tcx>,
+    fn_id: DefId,
+    expected_sig: ty::PolyFnSig<'tcx>,
+) {
+    let local_id = fn_id.as_local().unwrap_or(CRATE_DEF_ID);
+
+    let param_env = ty::ParamEnv::empty();
+
+    let infcx = &tcx.infer_ctxt().build();
+    let ocx = ObligationCtxt::new(infcx);
+
+    let actual_sig = tcx.fn_sig(fn_id).instantiate_identity();
+
+    let norm_cause = ObligationCause::misc(cause.span, local_id);
+    let actual_sig = ocx.normalize(&norm_cause, param_env, actual_sig);
+
+    match ocx.eq(&cause, param_env, expected_sig, actual_sig) {
+        Ok(()) => {
+            let errors = ocx.select_all_or_error();
+            if !errors.is_empty() {
+                infcx.err_ctxt().report_fulfillment_errors(&errors);
+                return;
+            }
+        }
+        Err(err) => {
+            let err_ctxt = infcx.err_ctxt();
+            if fn_id.is_local() {
+                cause.span = extract_span_for_error_reporting(tcx, err, &cause, local_id);
+            }
+            let failure_code = cause.as_failure_code_diag(err, cause.span, vec![]);
+            let mut diag = tcx.sess.create_err(failure_code);
+            err_ctxt.note_type_err(
+                &mut diag,
+                &cause,
+                None,
+                Some(infer::ValuePairs::PolySigs(ExpectedFound {
+                    expected: expected_sig,
+                    found: actual_sig,
+                })),
+                err,
+                false,
+                false,
+            );
+            diag.emit();
+            return;
+        }
+    }
+
+    let outlives_env = OutlivesEnvironment::new(param_env);
+    let _ = ocx.resolve_regions_and_report_errors(local_id, &outlives_env);
+
+    fn extract_span_for_error_reporting<'tcx>(
+        tcx: TyCtxt<'tcx>,
+        err: TypeError<'_>,
+        cause: &ObligationCause<'tcx>,
+        fn_id: LocalDefId,
+    ) -> rustc_span::Span {
+        let mut args = {
+            let node = tcx.hir().expect_owner(fn_id);
+            let decl = node.fn_decl().unwrap_or_else(|| bug!("expected fn decl, found {:?}", node));
+            decl.inputs.iter().map(|t| t.span).chain(std::iter::once(decl.output.span()))
+        };
+
+        match err {
+            TypeError::ArgumentMutability(i)
+            | TypeError::ArgumentSorts(ExpectedFound { .. }, i) => args.nth(i).unwrap(),
+            _ => cause.span(),
+        }
+    }
+}