Auto merge of #123982 - compiler-errors:rollup-m2v4epp, r=compiler-errors

Rollup of 4 pull requests

Successful merges:

 - #123900 (Stop using `PolyTraitRef` for closure/coroutine predicates already instantiated w placeholders)
 - #123924 (Fix various bugs in `ty_kind_suggestion`)
 - #123943 (Use the rustc_private libc less in tests)
 - #123970 (zkvm: fix references to `os_str` module)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -671,68 +671,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         err
     }
 
-    fn ty_kind_suggestion(&self, ty: Ty<'tcx>) -> Option<String> {
-        // Keep in sync with `rustc_hir_analysis/src/check/mod.rs:ty_kind_suggestion`.
-        // FIXME: deduplicate the above.
-        let tcx = self.infcx.tcx;
-        let implements_default = |ty| {
-            let Some(default_trait) = tcx.get_diagnostic_item(sym::Default) else {
-                return false;
-            };
-            self.infcx
-                .type_implements_trait(default_trait, [ty], self.param_env)
-                .must_apply_modulo_regions()
-        };
-
-        Some(match ty.kind() {
-            ty::Never | ty::Error(_) => return None,
-            ty::Bool => "false".to_string(),
-            ty::Char => "\'x\'".to_string(),
-            ty::Int(_) | ty::Uint(_) => "42".into(),
-            ty::Float(_) => "3.14159".into(),
-            ty::Slice(_) => "[]".to_string(),
-            ty::Adt(def, _) if Some(def.did()) == tcx.get_diagnostic_item(sym::Vec) => {
-                "vec![]".to_string()
-            }
-            ty::Adt(def, _) if Some(def.did()) == tcx.get_diagnostic_item(sym::String) => {
-                "String::new()".to_string()
-            }
-            ty::Adt(def, args) if def.is_box() => {
-                format!("Box::new({})", self.ty_kind_suggestion(args[0].expect_ty())?)
-            }
-            ty::Adt(def, _) if Some(def.did()) == tcx.get_diagnostic_item(sym::Option) => {
-                "None".to_string()
-            }
-            ty::Adt(def, args) if Some(def.did()) == tcx.get_diagnostic_item(sym::Result) => {
-                format!("Ok({})", self.ty_kind_suggestion(args[0].expect_ty())?)
-            }
-            ty::Adt(_, _) if implements_default(ty) => "Default::default()".to_string(),
-            ty::Ref(_, ty, mutability) => {
-                if let (ty::Str, hir::Mutability::Not) = (ty.kind(), mutability) {
-                    "\"\"".to_string()
-                } else {
-                    let Some(ty) = self.ty_kind_suggestion(*ty) else {
-                        return None;
-                    };
-                    format!("&{}{ty}", mutability.prefix_str())
-                }
-            }
-            ty::Array(ty, len) => format!(
-                "[{}; {}]",
-                self.ty_kind_suggestion(*ty)?,
-                len.eval_target_usize(tcx, ty::ParamEnv::reveal_all()),
-            ),
-            ty::Tuple(tys) => format!(
-                "({})",
-                tys.iter()
-                    .map(|ty| self.ty_kind_suggestion(ty))
-                    .collect::<Option<Vec<String>>>()?
-                    .join(", ")
-            ),
-            _ => "value".to_string(),
-        })
-    }
-
     fn suggest_assign_value(
         &self,
         err: &mut Diag<'_>,
@@ -742,7 +680,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         let ty = moved_place.ty(self.body, self.infcx.tcx).ty;
         debug!("ty: {:?}, kind: {:?}", ty, ty.kind());
 
-        let Some(assign_value) = self.ty_kind_suggestion(ty) else {
+        let Some(assign_value) = self.infcx.err_ctxt().ty_kind_suggestion(self.param_env, ty)
+        else {
             return;
         };
 

Diff for: compiler/rustc_hir_analysis/src/check/mod.rs

@@ -81,7 +81,6 @@ use rustc_errors::ErrorGuaranteed;
 use rustc_errors::{pluralize, struct_span_code_err, Diag};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::Visitor;
-use rustc_hir::Mutability;
 use rustc_index::bit_set::BitSet;
 use rustc_infer::infer::error_reporting::ObligationCauseExt as _;
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
@@ -96,8 +95,9 @@ use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::{def_id::CRATE_DEF_ID, BytePos, Span, Symbol, DUMMY_SP};
 use rustc_target::abi::VariantIdx;
 use rustc_target::spec::abi::Abi;
-use rustc_trait_selection::infer::InferCtxtExt;
-use rustc_trait_selection::traits::error_reporting::suggestions::ReturnsVisitor;
+use rustc_trait_selection::traits::error_reporting::suggestions::{
+    ReturnsVisitor, TypeErrCtxtExt as _,
+};
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
 use rustc_trait_selection::traits::ObligationCtxt;
 
@@ -467,67 +467,6 @@ fn fn_sig_suggestion<'tcx>(
     )
 }
 
-pub fn ty_kind_suggestion<'tcx>(ty: Ty<'tcx>, tcx: TyCtxt<'tcx>) -> Option<String> {
-    // Keep in sync with `rustc_borrowck/src/diagnostics/conflict_errors.rs:ty_kind_suggestion`.
-    // FIXME: deduplicate the above.
-    let implements_default = |ty| {
-        let Some(default_trait) = tcx.get_diagnostic_item(sym::Default) else {
-            return false;
-        };
-        let infcx = tcx.infer_ctxt().build();
-        infcx
-            .type_implements_trait(default_trait, [ty], ty::ParamEnv::reveal_all())
-            .must_apply_modulo_regions()
-    };
-    Some(match ty.kind() {
-        ty::Never | ty::Error(_) => return None,
-        ty::Bool => "false".to_string(),
-        ty::Char => "\'x\'".to_string(),
-        ty::Int(_) | ty::Uint(_) => "42".into(),
-        ty::Float(_) => "3.14159".into(),
-        ty::Slice(_) => "[]".to_string(),
-        ty::Adt(def, _) if Some(def.did()) == tcx.get_diagnostic_item(sym::Vec) => {
-            "vec![]".to_string()
-        }
-        ty::Adt(def, _) if Some(def.did()) == tcx.get_diagnostic_item(sym::String) => {
-            "String::new()".to_string()
-        }
-        ty::Adt(def, args) if def.is_box() => {
-            format!("Box::new({})", ty_kind_suggestion(args[0].expect_ty(), tcx)?)
-        }
-        ty::Adt(def, _) if Some(def.did()) == tcx.get_diagnostic_item(sym::Option) => {
-            "None".to_string()
-        }
-        ty::Adt(def, args) if Some(def.did()) == tcx.get_diagnostic_item(sym::Result) => {
-            format!("Ok({})", ty_kind_suggestion(args[0].expect_ty(), tcx)?)
-        }
-        ty::Adt(_, _) if implements_default(ty) => "Default::default()".to_string(),
-        ty::Ref(_, ty, mutability) => {
-            if let (ty::Str, Mutability::Not) = (ty.kind(), mutability) {
-                "\"\"".to_string()
-            } else {
-                let Some(ty) = ty_kind_suggestion(*ty, tcx) else {
-                    return None;
-                };
-                format!("&{}{ty}", mutability.prefix_str())
-            }
-        }
-        ty::Array(ty, len) => format!(
-            "[{}; {}]",
-            ty_kind_suggestion(*ty, tcx)?,
-            len.eval_target_usize(tcx, ty::ParamEnv::reveal_all()),
-        ),
-        ty::Tuple(tys) => format!(
-            "({})",
-            tys.iter()
-                .map(|ty| ty_kind_suggestion(ty, tcx))
-                .collect::<Option<Vec<String>>>()?
-                .join(", ")
-        ),
-        _ => "value".to_string(),
-    })
-}
-
 /// Return placeholder code for the given associated item.
 /// Similar to `ty::AssocItem::suggestion`, but appropriate for use as the code snippet of a
 /// structured suggestion.
@@ -562,7 +501,12 @@ fn suggestion_signature<'tcx>(
         }
         ty::AssocKind::Const => {
             let ty = tcx.type_of(assoc.def_id).instantiate_identity();
-            let val = ty_kind_suggestion(ty, tcx).unwrap_or_else(|| "value".to_string());
+            let val = tcx
+                .infer_ctxt()
+                .build()
+                .err_ctxt()
+                .ty_kind_suggestion(tcx.param_env(assoc.def_id), ty)
+                .unwrap_or_else(|| "value".to_string());
             format!("const {}: {} = {};", assoc.name, ty, val)
         }
     }