Update rustc to nightly-2021-02-15

prusti-tests/tests/verify/fail/no-annotations/panic-reason.rs

@@ -7,7 +7,8 @@ fn test_assert(x: bool) {
 }
 
 fn test_assert_msg(x: bool) {
-    assert!(false, "msg");  //~ ERROR the asserted expression might not hold
+    // FIXME: see mir_encoder encode_panic_cause
+    assert!(false, "msg");  //~ ERROR panic!(..) statement might be reachable
 }
 
 fn test_debug_assert(x: bool) {
@@ -65,7 +66,8 @@ fn test_inner_assert(x: bool) {
 macro_rules! inner_assert_msg {
     () => {
         {
-            assert!(false, "msg");  //~ ERROR the asserted expression might not hold
+            // FIXME: see mir_encoder encode_panic_cause
+            assert!(false, "msg");  //~ ERROR panic!(..) statement might be reachable
         }
     };
 }

prusti-viper/src/encoder/mir_encoder.rs

@@ -750,13 +750,15 @@ impl<'p, 'v: 'p, 'tcx: 'v> MirEncoder<'p, 'v, 'tcx> {
             .map(|x| x.as_str())
             .collect();
         match &macro_names_str[..] {
-            ["core::macros::panic", "std::unimplemented", ..] => PanicCause::Unimplemented,
-            ["core::macros::panic", "std::unreachable", ..] => PanicCause::Unreachable,
+            ["core::panic::panic_2015", "core::macros::panic", "std::unimplemented"] => PanicCause::Unimplemented,
+            ["core::panic::panic_2015", "core::macros::panic", "std::unreachable"] => PanicCause::Unreachable,
             ["std::assert", "std::debug_assert", ..] => PanicCause::DebugAssert,
             ["std::assert", ..] => PanicCause::Assert,
-            ["std::panic", "std::assert", "std::debug_assert", ..] => PanicCause::DebugAssert,
-            ["std::panic", "std::assert", ..] => PanicCause::Assert,
-            ["std::panic", ..] => PanicCause::Panic,
+            ["std::panic::panic_2015", "std::panic", "std::debug_assert"] => PanicCause::DebugAssert,
+            // TODO: assert!(_, "") currently has the same backtrace as panic!()
+            // see https://github.com/rust-lang/rust/issues/82157
+            //["std::panic::panic_2015", "std::panic", ..] => PanicCause::Assert,
+            ["std::panic::panic_2015", "std::panic", ..] => PanicCause::Panic,
             _ => PanicCause::Generic,
         }
     }

rust-toolchain

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2021-02-01"
+channel = "nightly-2021-02-15"
 components = [ "rustfmt", "rustc-dev", "llvm-tools-preview" ]