Handle diagnotics emitted in runtime initialization

Author: saethlin

src/eval.rs

@@ -168,6 +168,12 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
         param_env,
         Evaluator::new(config, layout_cx),
     );
+
+    // Capture the current interpreter stack state (which should be empty) so that we can emit
+    // allocation-tracking and tag-tracking diagnostics for allocations which are part of the
+    // runtime.
+    let info = ecx.preprocess_diagnostics();
+
     // Some parts of initialization require a full `InterpCx`.
     Evaluator::late_init(&mut ecx, config)?;
 
@@ -287,6 +293,10 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
         }
     }
 
+    // Emit any diagnostics related to the setup process for the runtime, so that when the
+    // interpreter loop starts there are no unprocessed diagnostics.
+    ecx.process_diagnostics(info);
+
     Ok((ecx, ret_place))
 }
 

tests/run-pass/track-alloc-1.rs

@@ -0,0 +1,5 @@
+// Ensure that tracking early allocations doesn't ICE Miri.
+// Early allocations are probably part of the runtime and therefore uninteresting, but they
+// shouldn't cause a crash.
+// compile-flags: -Zmiri-track-alloc-id=1
+fn main() {}

tests/run-pass/track-alloc-1.stderr

@@ -0,0 +1,5 @@
+note: tracking was triggered
+  |
+  = note: created allocation with id 1
+  = note: (no span available)
+