Always error on SizeOverflow during mir evaluation

src/librustc/mir/interpret/error.rs

@@ -137,17 +137,17 @@ impl<'tcx> ConstEvalErr<'tcx> {
         message: &str,
         lint_root: Option<hir::HirId>,
     ) -> Result<DiagnosticBuilder<'tcx>, ErrorHandled> {
-        match self.error {
+        let must_error = 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(_))) => true,
+            _ => false,
+        };
         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()
@@ -160,6 +160,8 @@ impl<'tcx> ConstEvalErr<'tcx> {
                 tcx.span,
                 message,
             )
+        } else if must_error {
+            struct_error(tcx, &self.error.to_string())
         } else {
             struct_error(tcx, message)
         };
@@ -335,7 +337,7 @@ 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/librustc_codegen_llvm/context.rs

@@ -30,6 +30,7 @@ use std::iter;
 use std::str;
 use std::sync::Arc;
 use syntax::symbol::LocalInternedString;
+use syntax::source_map::Span;
 use crate::abi::Abi;
 
 /// There is one `CodegenCx` per compilation unit. Each one has its own LLVM
@@ -860,9 +861,16 @@ impl LayoutOf for CodegenCx<'ll, 'tcx> {
     type TyLayout = TyLayout<'tcx>;
 
     fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyLayout {
+        self.spanned_layout_of(ty, None)
+    }
+
+    fn spanned_layout_of(&self, ty: Ty<'tcx>, span: Option<Span>) -> Self::TyLayout {
         self.tcx.layout_of(ty::ParamEnv::reveal_all().and(ty))
             .unwrap_or_else(|e| if let LayoutError::SizeOverflow(_) = e {
-                self.sess().fatal(&e.to_string())
+                match span {
+                    Some(span) => self.sess().span_fatal(span, &e.to_string()),
+                    None => self.sess().fatal(&e.to_string()),
+                }
             } else {
                 bug!("failed to get layout for `{}`: {}", ty, e)
             })

src/librustc_codegen_ssa/mir/analyze.rs

@@ -182,13 +182,19 @@ impl<'mir, 'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> Visitor<'tcx>
                     rvalue: &mir::Rvalue<'tcx>,
                     location: Location) {
         debug!("visit_assign(place={:?}, rvalue={:?})", place, rvalue);
+        let mut decl_span = None;
+        if let mir::PlaceBase::Local(local) = &place.base {
+            if let Some(decl) = self.fx.mir.local_decls.get(*local) {
+                decl_span = Some(decl.source_info.span);
+            }
+        }
 
         if let mir::Place {
             base: mir::PlaceBase::Local(index),
             projection: None,
         } = *place {
             self.assign(index, location);
-            if !self.fx.rvalue_creates_operand(rvalue) {
+            if !self.fx.rvalue_creates_operand(rvalue, decl_span) {
                 self.not_ssa(index);
             }
         } else {

src/librustc_codegen_ssa/mir/rvalue.rs

@@ -6,6 +6,7 @@ use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 use rustc_apfloat::{ieee, Float, Status, Round};
 use std::{u128, i128};
 use syntax::symbol::sym;
+use syntax::source_map::Span;
 
 use crate::base;
 use crate::MemFlags;
@@ -136,7 +137,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             }
 
             _ => {
-                assert!(self.rvalue_creates_operand(rvalue));
+                assert!(self.rvalue_creates_operand(rvalue, None));
                 let (mut bx, temp) = self.codegen_rvalue_operand(bx, rvalue);
                 temp.val.store(&mut bx, dest);
                 bx
@@ -169,7 +170,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         mut bx: Bx,
         rvalue: &mir::Rvalue<'tcx>
     ) -> (Bx, OperandRef<'tcx, Bx::Value>) {
-        assert!(self.rvalue_creates_operand(rvalue), "cannot codegen {:?} to operand", rvalue);
+        assert!(
+            self.rvalue_creates_operand(rvalue, None),
+            "cannot codegen {:?} to operand",
+            rvalue,
+        );
 
         match *rvalue {
             mir::Rvalue::Cast(ref kind, ref source, mir_cast_ty) => {
@@ -691,7 +696,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 }
 
 impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
-    pub fn rvalue_creates_operand(&self, rvalue: &mir::Rvalue<'tcx>) -> bool {
+    pub fn rvalue_creates_operand(&self, rvalue: &mir::Rvalue<'tcx>, span: Option<Span>) -> bool {
         match *rvalue {
             mir::Rvalue::Ref(..) |
             mir::Rvalue::Len(..) |
@@ -707,7 +712,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             mir::Rvalue::Aggregate(..) => {
                 let ty = rvalue.ty(self.mir, self.cx.tcx());
                 let ty = self.monomorphize(&ty);
-                self.cx.layout_of(ty).is_zst()
+                self.cx.spanned_layout_of(ty, span).is_zst()
             }
         }
 

src/librustc_mir/interpret/eval_context.rs

@@ -506,7 +506,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     pub fn push_stack_frame(
         &mut self,
         instance: ty::Instance<'tcx>,
-        span: source_map::Span,
+        span: Span,
         body: &'mir mir::Body<'tcx>,
         return_place: Option<PlaceTy<'tcx, M::PointerTag>>,
         return_to_block: StackPopCleanup,

src/librustc_target/abi/mod.rs

@@ -9,6 +9,7 @@ use std::ops::{Add, Deref, Sub, Mul, AddAssign, Range, RangeInclusive};
 use rustc_data_structures::newtype_index;
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
 use syntax_pos::symbol::{sym, Symbol};
+use syntax_pos::Span;
 
 pub mod call;
 
@@ -1012,6 +1013,9 @@ pub trait LayoutOf {
     type TyLayout;
 
     fn layout_of(&self, ty: Self::Ty) -> Self::TyLayout;
+    fn spanned_layout_of(&self, ty: Self::Ty, _span: Option<Span>) -> Self::TyLayout {
+        self.layout_of(ty)
+    }
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]

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

@@ -0,0 +1,4 @@
+// error-pattern: the type `[u8; 18446744073709551615]` is too big for the current architecture
+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]: the type `[u8; 18446744073709551615]` is too big for the current architecture
+  --> $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/huge-array-simple.stderr

@@ -1,4 +1,8 @@
 error: the type `[u8; N]` is too big for the current architecture
+  --> $DIR/huge-array-simple.rs:12:9
+   |
+LL |     let _fat : [u8; (1<<61)+(1<<31)] =
+   |         ^^^^
 
 error: aborting due to previous error
 

src/test/ui/huge-array.rs

@@ -1,11 +1,10 @@
-// error-pattern:; 1518600000
-
 // FIXME https://github.com/rust-lang/rust/issues/59774
 // normalize-stderr-test "thread.*panicked.*Metadata module not compiled.*\n" -> ""
 // normalize-stderr-test "note:.*RUST_BACKTRACE=1.*\n" -> ""
 
 fn generic<T: Copy>(t: T) {
     let s: [T; 1518600000] = [t; 1518600000];
+    //~^ ERROR the type `[[u8; 1518599999]; 1518600000]` is too big for the current architecture
 }
 
 fn main() {

src/test/ui/huge-array.stderr

@@ -1,4 +1,8 @@
 error: the type `[[u8; 1518599999]; 1518600000]` is too big for the current architecture
+  --> $DIR/huge-array.rs:6:9
+   |
+LL |     let s: [T; 1518600000] = [t; 1518600000];
+   |         ^
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-15919.stderr

@@ -1,4 +1,8 @@
 error: the type `[usize; N]` is too big for the current architecture
+  --> $DIR/issue-15919.rs:15:9
+   |
+LL |     let x = [0usize; 0xffff_ffff_ffff_ffff];
+   |         ^
 
 error: aborting due to previous error
 

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

@@ -17,6 +17,8 @@ impl TooBigArray {
 }
 
 static MY_TOO_BIG_ARRAY_1: TooBigArray = TooBigArray::new();
+//~^ ERROR the type `[u8; 2305843009213693951]` is too big for the current architecture
 static MY_TOO_BIG_ARRAY_2: [u8; HUGE_SIZE] = [0x00; HUGE_SIZE];
+//~^ ERROR the type `[u8; 2305843009213693951]` is too big for the current architecture
 
 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]: the type `[u8; 2305843009213693951]` is too big for the current architecture
+  --> $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]: the type `[u8; 2305843009213693951]` is too big for the current architecture
+  --> $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`.