avoid unwrap in Miri's adjust_global_allocation

Author: Strophox

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

@@ -358,11 +358,11 @@ impl Allocation {
     pub fn adjust_from_tcx<Prov: Provenance, Bytes: AllocBytes, Err>(
         &self,
         cx: &impl HasDataLayout,
-        mut alloc_bytes: impl FnMut(&[u8], Align) -> Bytes,
+        mut alloc_bytes: impl FnMut(&[u8], Align) -> Result<Bytes, Err>,
         mut adjust_ptr: impl FnMut(Pointer<CtfeProvenance>) -> Result<Pointer<Prov>, Err>,
     ) -> Result<Allocation<Prov, (), Bytes>, Err> {
         // Copy the data.
-        let mut bytes = alloc_bytes(&*self.bytes, self.align);
+        let mut bytes = alloc_bytes(&*self.bytes, self.align)?;
         // Adjust provenance of pointers stored in this allocation.
         let mut new_provenance = Vec::with_capacity(self.provenance.ptrs().len());
         let ptr_size = cx.data_layout().pointer_size.bytes_usize();

src/tools/miri/src/alloc_addresses/mod.rs

@@ -357,12 +357,11 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let ecx = self.eval_context_ref();
         // This additional call ensures that some `MiriAllocBytes` are prepared.
         ecx.addr_from_alloc_id(id, kind)?;
-        // TODO: Better debug message?
         let mut global_state = ecx.machine.alloc_addresses.borrow_mut();
         let prepared_alloc_bytes = global_state
             .prepared_alloc_bytes
             .remove(&id)
-            .expect("alloc bytes for {id:?} has not been prepared");
+            .unwrap_or_else(|| panic!("alloc bytes for {id:?} has not been prepared"));
         Ok(prepared_alloc_bytes)
     }
 

src/tools/miri/src/concurrency/thread.rs

@@ -887,7 +887,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             let alloc = this.ctfe_query(|tcx| tcx.eval_static_initializer(def_id))?;
             // We make a full copy of this allocation.
             let mut alloc =
-                alloc.inner().adjust_from_tcx(&this.tcx, |bytes, align| MiriAllocBytes::from_bytes(std::borrow::Cow::Borrowed(bytes), align), |ptr| this.global_root_pointer(ptr))?;
+                alloc.inner().adjust_from_tcx(&this.tcx, |bytes, align| Ok(MiriAllocBytes::from_bytes(std::borrow::Cow::Borrowed(bytes), align)), |ptr| this.global_root_pointer(ptr))?;
             // This allocation will be deallocated when the thread dies, so it is not in read-only memory.
             alloc.mutability = Mutability::Mut;
             // Create a fresh allocation with this content.

src/tools/miri/src/machine.rs

@@ -1249,12 +1249,11 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
         let alloc = alloc.adjust_from_tcx(&ecx.tcx, |bytes, align| {
                 assert_eq!(alloc.align, align);
                 let kind = Self::GLOBAL_KIND.unwrap().into();
-                // TODO: is this unwrap warranted?
-                let mut alloc_bytes = ecx.take_prepared_alloc_bytes(id, kind).unwrap();
+                let mut alloc_bytes = ecx.take_prepared_alloc_bytes(id, kind)?;
                 assert_eq!(alloc_bytes.len(), bytes.len());
                 // SAFETY: `alloc_bytes` and `bytes` span the same number of bytes.
                 unsafe { alloc_bytes.as_mut_ptr().copy_from(bytes.as_ptr(), bytes.len()) };
-                alloc_bytes
+                Ok(alloc_bytes)
             }, 
             |ptr| ecx.global_root_pointer(ptr),
         )?;