Add const_str_ptr and mut_str_ptr lang items

These items allow to make inherent impls for `*const str` and `*mut str`.

Author: WaffleLapkin

compiler/rustc_hir/src/lang_items.rs

@@ -184,7 +184,9 @@ language_item_table! {
     ConstPtr,                sym::const_ptr,           const_ptr_impl,             Target::Impl,           GenericRequirement::None;
     MutPtr,                  sym::mut_ptr,             mut_ptr_impl,               Target::Impl,           GenericRequirement::None;
     ConstSlicePtr,           sym::const_slice_ptr,     const_slice_ptr_impl,       Target::Impl,           GenericRequirement::None;
+    ConstStrPtr,             sym::const_str_ptr,       const_str_ptr_impl,         Target::Impl,           GenericRequirement::None;
     MutSlicePtr,             sym::mut_slice_ptr,       mut_slice_ptr_impl,         Target::Impl,           GenericRequirement::None;
+    MutStrPtr,               sym::mut_str_ptr,         mut_str_ptr_impl,           Target::Impl,           GenericRequirement::None;
     I8,                      sym::i8,                  i8_impl,                    Target::Impl,           GenericRequirement::None;
     I16,                     sym::i16,                 i16_impl,                   Target::Impl,           GenericRequirement::None;
     I32,                     sym::i32,                 i32_impl,                   Target::Impl,           GenericRequirement::None;

compiler/rustc_span/src/symbol.rs

@@ -458,6 +458,7 @@ symbols! {
         const_raw_ptr_to_usize_cast,
         const_refs_to_cell,
         const_slice_ptr,
+        const_str_ptr,
         const_trait_bound_opt_out,
         const_trait_impl,
         const_transmute,
@@ -839,6 +840,7 @@ symbols! {
         must_use,
         mut_ptr,
         mut_slice_ptr,
+        mut_str_ptr,
         naked,
         naked_functions,
         name,

compiler/rustc_typeck/src/check/method/probe.rs

@@ -680,16 +680,21 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                 self.assemble_inherent_impl_for_primitive(lang_def_id);
             }
             ty::RawPtr(ty::TypeAndMut { ty: _, mutbl }) => {
-                let (lang_def_id1, lang_def_id2) = match mutbl {
-                    hir::Mutability::Not => {
-                        (lang_items.const_ptr_impl(), lang_items.const_slice_ptr_impl())
-                    }
-                    hir::Mutability::Mut => {
-                        (lang_items.mut_ptr_impl(), lang_items.mut_slice_ptr_impl())
-                    }
+                let (lang_def_id1, lang_def_id2, lang_def_id3) = match mutbl {
+                    hir::Mutability::Not => (
+                        lang_items.const_ptr_impl(),
+                        lang_items.const_slice_ptr_impl(),
+                        lang_items.const_str_ptr_impl(),
+                    ),
+                    hir::Mutability::Mut => (
+                        lang_items.mut_ptr_impl(),
+                        lang_items.mut_slice_ptr_impl(),
+                        lang_items.mut_str_ptr_impl(),
+                    ),
                 };
                 self.assemble_inherent_impl_for_primitive(lang_def_id1);
                 self.assemble_inherent_impl_for_primitive(lang_def_id2);
+                self.assemble_inherent_impl_for_primitive(lang_def_id3);
             }
             ty::Int(i) => {
                 let lang_def_id = match i {

compiler/rustc_typeck/src/coherence/inherent_impls.rs

@@ -150,6 +150,19 @@ impl ItemLikeVisitor<'v> for InherentCollect<'tcx> {
                     assoc_items,
                 );
             }
+            ty::RawPtr(ty::TypeAndMut { ty: inner, mutbl: hir::Mutability::Not })
+                if matches!(inner.kind(), ty::Str) =>
+            {
+                self.check_primitive_impl(
+                    item.def_id,
+                    lang_items.const_str_ptr_impl(),
+                    None,
+                    "const_str_ptr",
+                    "*const str",
+                    item.span,
+                    assoc_items,
+                );
+            }
             ty::RawPtr(ty::TypeAndMut { ty: inner, mutbl: hir::Mutability::Mut })
                 if matches!(inner.kind(), ty::Slice(_)) =>
             {
@@ -163,6 +176,19 @@ impl ItemLikeVisitor<'v> for InherentCollect<'tcx> {
                     assoc_items,
                 );
             }
+            ty::RawPtr(ty::TypeAndMut { ty: inner, mutbl: hir::Mutability::Mut })
+                if matches!(inner.kind(), ty::Str) =>
+            {
+                self.check_primitive_impl(
+                    item.def_id,
+                    lang_items.mut_str_ptr_impl(),
+                    None,
+                    "mut_str_ptr",
+                    "*mut str",
+                    item.span,
+                    assoc_items,
+                );
+            }
             ty::RawPtr(ty::TypeAndMut { ty: _, mutbl: hir::Mutability::Not }) => {
                 self.check_primitive_impl(
                     item.def_id,