Auto merge of #150523 - Kivooeo:add-check-for-u8, r=BoxyUwU

add check for `u8`s in `lit_to_const`

Fixes #131052

r? BoxyUwU

Author: bors

compiler/rustc_mir_build/src/thir/constant.rs

@@ -1,5 +1,5 @@
 use rustc_abi::Size;
-use rustc_ast::{self as ast};
+use rustc_ast::{self as ast, UintTy};
 use rustc_hir::LangItem;
 use rustc_middle::bug;
 use rustc_middle::mir::interpret::LitToConstInput;
@@ -44,12 +44,14 @@ pub(crate) fn lit_to_const<'tcx>(
             ty::ValTree::from_raw_bytes(tcx, str_bytes)
         }
         (ast::LitKind::ByteStr(byte_sym, _), ty::Ref(_, inner_ty, _))
-            if matches!(inner_ty.kind(), ty::Slice(_) | ty::Array(..)) =>
+            if let ty::Slice(ty) | ty::Array(ty, _) = inner_ty.kind()
+                && let ty::Uint(UintTy::U8) = ty.kind() =>
         {
             ty::ValTree::from_raw_bytes(tcx, byte_sym.as_byte_str())
         }
-        (ast::LitKind::ByteStr(byte_sym, _), ty::Slice(_) | ty::Array(..))
-            if tcx.features().deref_patterns() =>
+        (ast::LitKind::ByteStr(byte_sym, _), ty::Slice(inner_ty) | ty::Array(inner_ty, _))
+            if tcx.features().deref_patterns()
+                && let ty::Uint(UintTy::U8) = inner_ty.kind() =>
         {
             // Byte string literal patterns may have type `[u8]` or `[u8; N]` if `deref_patterns` is
             // enabled, in order to allow, e.g., `deref!(b"..."): Vec<u8>`.

tests/ui/const-generics/adt_const_params/byte-string-u8-validation.rs

@@ -0,0 +1,18 @@
+// Check that a byte string literal to a const parameter with a non-u8
+// element type isn't lowered to a ValTree with an incorrect type
+
+#![feature(adt_const_params)]
+#![feature(rustc_attrs)]
+
+#[rustc_dump_predicates]
+struct ConstBytes<const T: &'static [*mut u8; 3]>
+//~^ ERROR rustc_dump_predicates
+//~| NOTE Binder { value: ConstArgHasType(T/#0, &'static [*mut u8; 3_usize]), bound_vars: [] }
+//~| NOTE Binder { value: TraitPredicate(<ConstBytes<{const error}> as std::marker::Sized>, polarity:Positive), bound_vars: [] }
+where
+    ConstBytes<b"AAA">: Sized;
+//~^ ERROR mismatched types
+//~| NOTE expected `&[*mut u8; 3]`, found `&[u8; 3]`
+//~| NOTE expected reference `&'static [*mut u8; 3]`
+
+fn main() {}

tests/ui/const-generics/adt_const_params/byte-string-u8-validation.stderr

@@ -0,0 +1,21 @@
+error: rustc_dump_predicates
+  --> $DIR/byte-string-u8-validation.rs:8:1
+   |
+LL | struct ConstBytes<const T: &'static [*mut u8; 3]>
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: Binder { value: ConstArgHasType(T/#0, &'static [*mut u8; 3_usize]), bound_vars: [] }
+   = note: Binder { value: TraitPredicate(<ConstBytes<{const error}> as std::marker::Sized>, polarity:Positive), bound_vars: [] }
+
+error[E0308]: mismatched types
+  --> $DIR/byte-string-u8-validation.rs:13:16
+   |
+LL |     ConstBytes<b"AAA">: Sized;
+   |                ^^^^^^ expected `&[*mut u8; 3]`, found `&[u8; 3]`
+   |
+   = note: expected reference `&'static [*mut u8; 3]`
+              found reference `&'static [u8; 3]`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.

tests/ui/const-generics/adt_const_params/mismatch-raw-ptr-in-adt.rs

@@ -9,5 +9,4 @@ pub fn main() {
     let _: ConstBytes<b"AAA"> = ConstBytes::<b"BBB">;
     //~^ ERROR mismatched types
     //~| ERROR mismatched types
-    //~| ERROR mismatched types
 }

tests/ui/const-generics/adt_const_params/mismatch-raw-ptr-in-adt.stderr

@@ -7,17 +7,6 @@ LL | struct ConstBytes<const T: &'static [*mut u8; 3]>;
    = note: `*mut u8` must implement `ConstParamTy_`, but it does not
    = note: `[*mut u8; 3]` must implement `ConstParamTy_`, but it does not
 
-error[E0308]: mismatched types
-  --> $DIR/mismatch-raw-ptr-in-adt.rs:9:33
-   |
-LL |     let _: ConstBytes<b"AAA"> = ConstBytes::<b"BBB">;
-   |            ------------------   ^^^^^^^^^^^^^^^^^^^^ expected `&[65, 65, 65]`, found `&[66, 66, 66]`
-   |            |
-   |            expected due to this
-   |
-   = note: expected struct `ConstBytes<&[65, 65, 65]>`
-              found struct `ConstBytes<&[66, 66, 66]>`
-
 error[E0308]: mismatched types
   --> $DIR/mismatch-raw-ptr-in-adt.rs:9:46
    |
@@ -36,7 +25,7 @@ LL |     let _: ConstBytes<b"AAA"> = ConstBytes::<b"BBB">;
    = note: expected reference `&'static [*mut u8; 3]`
               found reference `&'static [u8; 3]`
 
-error: aborting due to 4 previous errors
+error: aborting due to 3 previous errors
 
 Some errors have detailed explanations: E0308, E0741.
 For more information about an error, try `rustc --explain E0308`.