Always error on SizeOverflow during mir evaluation

src/librustc/mir/interpret/error.rs

@@ -137,17 +137,18 @@ impl<'tcx> ConstEvalErr<'tcx> {
         message: &str,
         lint_root: Option<hir::HirId>,
     ) -> Result<DiagnosticBuilder<'tcx>, ErrorHandled> {
+        let mut must_error = false;
         match self.error {
             err_inval!(Layout(LayoutError::Unknown(_))) |
             err_inval!(TooGeneric) =>
                 return Err(ErrorHandled::TooGeneric),
-            err_inval!(Layout(LayoutError::SizeOverflow(_))) |
             err_inval!(TypeckError) =>
                 return Err(ErrorHandled::Reported),
+            err_inval!(Layout(LayoutError::SizeOverflow(_))) => must_error = true,
             _ => {},
         }
         trace!("reporting const eval failure at {:?}", self.span);
-        let mut err = if let Some(lint_root) = lint_root {
+        let mut err = if let (Some(lint_root), false) = (lint_root, must_error) {
             let hir_id = self.stacktrace
                 .iter()
                 .rev()
@@ -335,7 +336,7 @@ impl fmt::Debug for InvalidProgramInfo<'tcx> {
             TypeckError =>
                 write!(f, "encountered constants with type errors, stopping evaluation"),
             Layout(ref err) =>
-                write!(f, "rustc layout computation failed: {:?}", err),
+                write!(f, "{}", err),
         }
     }
 }

src/test/ui/consts/issue-55878.rs

@@ -0,0 +1,4 @@
+// error-pattern: reaching this expression at runtime will panic or abort
+fn main() {
+    println!("Size: {}", std::mem::size_of::<[u8; std::u64::MAX as usize]>());
+}

src/test/ui/consts/issue-55878.stderr

@@ -0,0 +1,14 @@
+error[E0080]: reaching this expression at runtime will panic or abort
+  --> $SRC_DIR/libcore/mem/mod.rs:LL:COL
+   |
+LL |     intrinsics::size_of::<T>()
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ the type `[u8; 18446744073709551615]` is too big for the current architecture
+   | 
+  ::: $DIR/issue-55878.rs:3:26
+   |
+LL |     println!("Size: {}", std::mem::size_of::<[u8; std::u64::MAX as usize]>());
+   |                          ---------------------------------------------------
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0080`.

src/test/ui/issues/issue-56762.rs

@@ -17,6 +17,8 @@ impl TooBigArray {
 }
 
 static MY_TOO_BIG_ARRAY_1: TooBigArray = TooBigArray::new();
+//~^ ERROR could not evaluate static initializer
 static MY_TOO_BIG_ARRAY_2: [u8; HUGE_SIZE] = [0x00; HUGE_SIZE];
+//~^ ERROR could not evaluate static initializer
 
 fn main() { }

src/test/ui/issues/issue-56762.stderr

@@ -1,4 +1,15 @@
-error: the type `[u8; 2305843009213693951]` is too big for the current architecture
+error[E0080]: could not evaluate static initializer
+  --> $DIR/issue-56762.rs:19:1
+   |
+LL | static MY_TOO_BIG_ARRAY_1: TooBigArray = TooBigArray::new();
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the type `[u8; 2305843009213693951]` is too big for the current architecture
 
-error: aborting due to previous error
+error[E0080]: could not evaluate static initializer
+  --> $DIR/issue-56762.rs:21:1
+   |
+LL | static MY_TOO_BIG_ARRAY_2: [u8; HUGE_SIZE] = [0x00; HUGE_SIZE];
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the type `[u8; 2305843009213693951]` is too big for the current architecture
 
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0080`.