fix handling of unsized types in validation; validate str to be UTF-8

2 files changed, 80 insertions, 25 deletions

diff --git a/src/test/ui/union-ub-fat-ptr.rs b/src/test/ui/union-ub-fat-ptr.rs
index ffa824fc6af..0c42d28eb00 100644
--- a/src/test/ui/union-ub-fat-ptr.rs
+++ b/src/test/ui/union-ub-fat-ptr.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unused)]
+
 // normalize-stderr-test "alignment \d+" -> "alignment N"
 // normalize-stderr-test "offset \d+" -> "offset N"
 // normalize-stderr-test "allocation \d+" -> "allocation N"
@@ -37,7 +39,8 @@ union SliceTransmute {
     bad: BadSliceRepr,
     slice: &'static [u8],
     str: &'static str,
-    my_str: &'static Str,
+    my_str: &'static MyStr,
+    my_slice: &'static MySliceBool,
 }
 
 #[repr(C)]
@@ -71,7 +74,12 @@ union DynTransmute {
 trait Trait {}
 impl Trait for bool {}
 
-struct Str(str);
+// custom unsized type
+struct MyStr(str);
+
+// custom unsized type with sized fields
+struct MySlice<T: ?Sized>(bool, T);
+type MySliceBool = MySlice<[bool]>;
 
 // OK
 const A: &str = unsafe { SliceTransmute { repr: SliceRepr { ptr: &42, len: 1 } }.str};
@@ -81,8 +89,8 @@ const B: &str = unsafe { SliceTransmute { repr: SliceRepr { ptr: &42, len: 999 }
 // bad str
 const C: &str = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.str};
 //~^ ERROR this constant likely exhibits undefined behavior
-// bad str in Str
-const C2: &Str = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.my_str};
+// bad str in user-defined unsized type
+const C2: &MyStr = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.my_str};
 //~^ ERROR this constant likely exhibits undefined behavior
 
 // OK
@@ -107,10 +115,25 @@ const F: &Trait = unsafe { DynTransmute { bad: BadDynRepr { ptr: &92, vtable: 3
 // bad data *inside* the trait object
 const G: &Trait = &unsafe { BoolTransmute { val: 3 }.bl };
 //~^ ERROR this constant likely exhibits undefined behavior
-
 // bad data *inside* the slice
 const H: &[bool] = &[unsafe { BoolTransmute { val: 3 }.bl }];
 //~^ ERROR this constant likely exhibits undefined behavior
 
+// good MySliceBool
+const I1: &MySliceBool = &MySlice(true, [false]);
+// bad: sized field is not okay
+const I2: &MySliceBool = &MySlice(unsafe { BoolTransmute { val: 3 }.bl }, [false]);
+//~^ ERROR this constant likely exhibits undefined behavior
+// bad: unsized part is not okay
+const I3: &MySliceBool = &MySlice(true, [unsafe { BoolTransmute { val: 3 }.bl }]);
+//~^ ERROR this constant likely exhibits undefined behavior
+
+// invalid UTF-8
+const J1: &str = unsafe { SliceTransmute { slice: &[0xFF] }.str };
+//~^ ERROR this constant likely exhibits undefined behavior
+// invalid UTF-8 in user-defined str-like
+const J2: &MyStr = unsafe { SliceTransmute { slice: &[0xFF] }.my_str };
+//~^ ERROR this constant likely exhibits undefined behavior
+
 fn main() {
 }
diff --git a/src/test/ui/union-ub-fat-ptr.stderr b/src/test/ui/union-ub-fat-ptr.stderr
index cc22422304d..5d817dce205 100644
--- a/src/test/ui/union-ub-fat-ptr.stderr
+++ b/src/test/ui/union-ub-fat-ptr.stderr
@@ -1,69 +1,69 @@
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:79:1
+  --> $DIR/union-ub-fat-ptr.rs:87:1
    |
 LL | const B: &str = unsafe { SliceTransmute { repr: SliceRepr { ptr: &42, len: 999 } }.str};
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ memory access at offset N, outside bounds of allocation N which has size N
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized or out-of-bounds memory at .<deref>
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:82:1
+  --> $DIR/union-ub-fat-ptr.rs:90:1
    |
 LL | const C: &str = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.str};
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered fat pointer length is not a valid integer
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered non-integer slice length in fat pointer
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:85:1
+  --> $DIR/union-ub-fat-ptr.rs:93:1
    |
-LL | const C2: &Str = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.my_str};
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered fat pointer length is not a valid integer
+LL | const C2: &MyStr = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.my_str};
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered non-integer slice length in fat pointer
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:91:1
+  --> $DIR/union-ub-fat-ptr.rs:99:1
    |
 LL | const B2: &[u8] = unsafe { SliceTransmute { repr: SliceRepr { ptr: &42, len: 999 } }.slice};
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ memory access at offset N, outside bounds of allocation N which has size N
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized or out-of-bounds memory at .<deref>[1]
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:94:1
+  --> $DIR/union-ub-fat-ptr.rs:102:1
    |
 LL | const C3: &[u8] = unsafe { SliceTransmute { bad: BadSliceRepr { ptr: &42, len: &3 } }.slice};
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered fat pointer length is not a valid integer
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered non-integer slice length in fat pointer
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:98:1
+  --> $DIR/union-ub-fat-ptr.rs:106:1
    |
 LL | const D: &Trait = unsafe { DynTransmute { repr: DynRepr { ptr: &92, vtable: &3 } }.rust};
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ tried to access memory with alignment N, but alignment N is required
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered invalid vtable in fat pointer at .<deref>
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:101:1
+  --> $DIR/union-ub-fat-ptr.rs:109:1
    |
 LL | const E: &Trait = unsafe { DynTransmute { repr2: DynRepr2 { ptr: &92, vtable: &3 } }.rust};
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ a memory access tried to interpret some bytes as a pointer
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered invalid vtable in fat pointer at .<deref>
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:104:1
+  --> $DIR/union-ub-fat-ptr.rs:112:1
    |
 LL | const F: &Trait = unsafe { DynTransmute { bad: BadDynRepr { ptr: &92, vtable: 3 } }.rust};
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered fat pointer vtable is not a valid pointer
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered non-pointer vtable in fat pointer
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:108:1
+  --> $DIR/union-ub-fat-ptr.rs:116:1
    |
 LL | const G: &Trait = &unsafe { BoolTransmute { val: 3 }.bl };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at .<deref>, but expected something in the range 0..=1
@@ -71,13 +71,45 @@ LL | const G: &Trait = &unsafe { BoolTransmute { val: 3 }.bl };
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: this constant likely exhibits undefined behavior
-  --> $DIR/union-ub-fat-ptr.rs:112:1
+  --> $DIR/union-ub-fat-ptr.rs:119:1
    |
 LL | const H: &[bool] = &[unsafe { BoolTransmute { val: 3 }.bl }];
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at .<deref>[0], but expected something in the range 0..=1
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
-error: aborting due to 10 previous errors
+error[E0080]: this constant likely exhibits undefined behavior
+  --> $DIR/union-ub-fat-ptr.rs:125:1
+   |
+LL | const I2: &MySliceBool = &MySlice(unsafe { BoolTransmute { val: 3 }.bl }, [false]);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at .<deref>.0, but expected something in the range 0..=1
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
+
+error[E0080]: this constant likely exhibits undefined behavior
+  --> $DIR/union-ub-fat-ptr.rs:128:1
+   |
+LL | const I3: &MySliceBool = &MySlice(true, [unsafe { BoolTransmute { val: 3 }.bl }]);
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 3 at .<deref>.1[0], but expected something in the range 0..=1
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
+
+error[E0080]: this constant likely exhibits undefined behavior
+  --> $DIR/union-ub-fat-ptr.rs:132:1
+   |
+LL | const J1: &str = unsafe { SliceTransmute { slice: &[0xFF] }.str };
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered non-UTF-8 data in str at .<deref>
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
+
+error[E0080]: this constant likely exhibits undefined behavior
+  --> $DIR/union-ub-fat-ptr.rs:135:1
+   |
+LL | const J2: &MyStr = unsafe { SliceTransmute { slice: &[0xFF] }.my_str };
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered non-UTF-8 data in str at .<deref>.0
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
+
+error: aborting due to 14 previous errors
 
 For more information about this error, try `rustc --explain E0080`.