Rollup merge of #153564 - RalfJung:oom-is-not-ice, r=oli-obk

rendering interpreter OOM as OOM instead of ICE

Fixes #149643.
Alternative to #153481.

Author: JonathanBrouwer

compiler/rustc_middle/src/mir/interpret/allocation.rs

@@ -3,6 +3,7 @@
 mod init_mask;
 mod provenance_map;
 
+use std::alloc::{self, Layout};
 use std::borrow::Cow;
 use std::hash::Hash;
 use std::ops::{Deref, DerefMut, Range};
@@ -434,7 +435,7 @@ impl<Prov: Provenance, Bytes: AllocBytes> Allocation<Prov, (), Bytes> {
         // available to the compiler can change between runs. Normally queries are always
         // deterministic. However, we can be non-deterministic here because all uses of const
         // evaluation (including ConstProp!) will make compilation fail (via hard error
-        // or ICE) upon encountering a `MemoryExhausted` error.
+        // or OOM) upon encountering a `MemoryExhausted` error.
         let bytes = Bytes::zeroed(size, align, params).ok_or_else(fail)?;
 
         Ok(Allocation {
@@ -468,7 +469,7 @@ impl<Prov: Provenance, Bytes: AllocBytes> Allocation<Prov, (), Bytes> {
         .into()
     }
 
-    /// Try to create an Allocation of `size` bytes, panics if there is not enough memory
+    /// Try to create an Allocation of `size` bytes. Aborts if there is not enough memory
     /// available to the compiler to do so.
     ///
     /// Example use case: To obtain an Allocation filled with specific data,
@@ -480,10 +481,15 @@ impl<Prov: Provenance, Bytes: AllocBytes> Allocation<Prov, (), Bytes> {
         params: <Bytes as AllocBytes>::AllocParams,
     ) -> Self {
         match Self::new_inner(size, align, init, params, || {
-            panic!(
-                "interpreter ran out of memory: cannot create allocation of {} bytes",
-                size.bytes()
-            );
+            // `size` may actually be bigger than isize::MAX since it is a *target* size.
+            // Clamp it to isize::MAX to still give a somewhat reasonable error message.
+            alloc::handle_alloc_error(
+                Layout::from_size_align(
+                    size.bytes().min(isize::MAX as u64) as usize,
+                    align.bytes_usize(),
+                )
+                .unwrap(),
+            )
         }) {
             Ok(x) => x,
             Err(x) => x,