Auto merge of #1239 - elichai:2020-03-abort-intrinsics, r=RalfJung

Abort instead of panic on asserting intrinsics

This fixes #1222
replacing the panic with an abort and a corresponding message.
the stack trace is already printed, this just adds an optional message the caller can pass, and I just pass the same message we passed to the panic but now to the abort instead.

r? @RalfJung

src/diagnostics.rs

@@ -20,7 +20,8 @@ pub fn report_diagnostic<'tcx, 'mir>(
             let info = info.downcast_ref::<TerminationInfo>().expect("invalid MachineStop payload");
             match info {
                 TerminationInfo::Exit(code) => return Some(*code),
-                TerminationInfo::Abort => format!("the evaluated program aborted execution"),
+                TerminationInfo::Abort(None) => format!("the evaluated program aborted execution"),
+                TerminationInfo::Abort(Some(msg)) => format!("the evaluated program aborted execution: {}", msg),
             }
         }
         err_unsup!(NoMirFor(..)) => format!(

src/eval.rs

@@ -54,7 +54,7 @@ impl Default for MiriConfig {
 /// Details of premature program termination.
 pub enum TerminationInfo {
     Exit(i64),
-    Abort,
+    Abort(Option<String>),
 }
 
 /// Returns a freshly created `InterpCx`, along with an `MPlaceTy` representing

src/machine.rs

@@ -273,7 +273,7 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'tcx> {
 
     #[inline(always)]
     fn abort(_ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx, !> {
-        throw_machine_stop!(TerminationInfo::Abort)
+        throw_machine_stop!(TerminationInfo::Abort(None))
     }
 
     #[inline(always)]

src/shims/intrinsics.rs

@@ -410,15 +410,15 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             "assert_uninit_valid" => {
                 let ty = substs.type_at(0);
                 let layout = this.layout_of(ty)?;
-                // Return here because we panicked instead of returning normally from the intrinsic.
+                // Abort here because the caller might not be panic safe.
                 if layout.abi.is_uninhabited() {
-                    return this.start_panic(&format!("attempted to instantiate uninhabited type `{}`", ty), unwind);
+                    throw_machine_stop!(TerminationInfo::Abort(Some(format!("attempted to instantiate uninhabited type `{}`", ty))))
                 }
                 if intrinsic_name == "assert_zero_valid" && !layout.might_permit_raw_init(this, /*zero:*/ true).unwrap() {
-                    return this.start_panic(&format!("attempted to zero-initialize type `{}`, which is invalid", ty), unwind);
+                    throw_machine_stop!(TerminationInfo::Abort(Some(format!("attempted to zero-initialize type `{}`, which is invalid", ty))))
                 }
                 if intrinsic_name == "assert_uninit_valid" && !layout.might_permit_raw_init(this, /*zero:*/ false).unwrap() {
-                    return this.start_panic(&format!("attempted to leave type `{}` uninitialized, which is invalid", ty), unwind);
+                    throw_machine_stop!(TerminationInfo::Abort(Some(format!("attempted to leave type `{}` uninitialized, which is invalid", ty))))
                 }
             }
 

tests/compile-fail/invalid_zero_init.rs

@@ -0,0 +1,6 @@
+ // error-pattern: the evaluated program aborted execution: attempted to zero-initialize type `fn()`, which is invalid
+
+#[allow(deprecated, invalid_value)]
+fn main() {
+    unsafe { std::mem::zeroed::<fn()>() };
+}

tests/compile-fail/uninit_uninhabited_type.rs

@@ -0,0 +1,7 @@
+ // error-pattern: the evaluated program aborted execution: attempted to instantiate uninhabited type `!`
+#![feature(never_type)]
+
+#[allow(deprecated, invalid_value)]
+fn main() {
+    unsafe { std::mem::uninitialized::<!>() };
+}

tests/run-pass/panic/catch_panic.rs

@@ -67,43 +67,6 @@ fn main() {
         |_old_val| { let _val = 1/0; loop {} },
     );
 
-    // libcore panics from shims.
-    #[allow(deprecated, invalid_value)]
-    {
-        test(
-            Some("attempted to instantiate uninhabited type `!`"),
-            |_old_val| unsafe { std::mem::uninitialized::<!>() },
-        );
-        test(
-            Some("attempted to instantiate uninhabited type `!`"),
-            |_old_val| unsafe { std::mem::zeroed::<!>() },
-        );
-        test(
-            Some("attempted to leave type `fn()` uninitialized, which is invalid"),
-            |_old_val| unsafe { std::mem::uninitialized::<fn()>(); loop {} },
-        );
-        test(
-            Some("attempted to zero-initialize type `fn()`, which is invalid"),
-            |_old_val| unsafe { std::mem::zeroed::<fn()>(); loop {} },
-        );
-        test(
-            Some("attempted to leave type `*const dyn std::marker::Sync` uninitialized, which is invalid"),
-            |_old_val| unsafe { std::mem::uninitialized::<*const dyn Sync>(); loop {} },
-        );
-        test(
-            Some("attempted to zero-initialize type `*mut dyn std::marker::Sync`, which is invalid"),
-            |_old_val| unsafe { std::mem::zeroed::<*mut dyn Sync>(); loop {} },
-        );
-        test(
-            Some("attempted to leave type `&u8` uninitialized, which is invalid"),
-            |_old_val| unsafe { std::mem::uninitialized::<&u8>(); loop {} },
-        );
-        test(
-            Some("attempted to zero-initialize type `&u8`, which is invalid"),
-            |_old_val| unsafe { std::mem::zeroed::<&u8>(); loop {} },
-        );
-    }
-
     test(
         Some("align_offset: align is not a power-of-two"),
         |_old_val| { (0usize as *const u8).align_offset(3); loop {} },

tests/run-pass/panic/catch_panic.stderr

@@ -16,27 +16,11 @@ thread 'main' panicked at 'index out of bounds: the len is 3 but the index is 4'
 Caught panic message (String): index out of bounds: the len is 3 but the index is 4
 thread 'main' panicked at 'attempt to divide by zero', $DIR/catch_panic.rs:67:33
 Caught panic message (String): attempt to divide by zero
-thread 'main' panicked at 'attempted to instantiate uninhabited type `!`', $LOC
-Caught panic message (String): attempted to instantiate uninhabited type `!`
-thread 'main' panicked at 'attempted to instantiate uninhabited type `!`', $LOC
-Caught panic message (String): attempted to instantiate uninhabited type `!`
-thread 'main' panicked at 'attempted to leave type `fn()` uninitialized, which is invalid', $LOC
-Caught panic message (String): attempted to leave type `fn()` uninitialized, which is invalid
-thread 'main' panicked at 'attempted to zero-initialize type `fn()`, which is invalid', $LOC
-Caught panic message (String): attempted to zero-initialize type `fn()`, which is invalid
-thread 'main' panicked at 'attempted to leave type `*const dyn std::marker::Sync` uninitialized, which is invalid', $LOC
-Caught panic message (String): attempted to leave type `*const dyn std::marker::Sync` uninitialized, which is invalid
-thread 'main' panicked at 'attempted to zero-initialize type `*mut dyn std::marker::Sync`, which is invalid', $LOC
-Caught panic message (String): attempted to zero-initialize type `*mut dyn std::marker::Sync`, which is invalid
-thread 'main' panicked at 'attempted to leave type `&u8` uninitialized, which is invalid', $LOC
-Caught panic message (String): attempted to leave type `&u8` uninitialized, which is invalid
-thread 'main' panicked at 'attempted to zero-initialize type `&u8`, which is invalid', $LOC
-Caught panic message (String): attempted to zero-initialize type `&u8`, which is invalid
 thread 'main' panicked at 'align_offset: align is not a power-of-two', $LOC
 Caught panic message (String): align_offset: align is not a power-of-two
-thread 'main' panicked at 'assertion failed: false', $DIR/catch_panic.rs:113:29
+thread 'main' panicked at 'assertion failed: false', $DIR/catch_panic.rs:76:29
 Caught panic message (&str): assertion failed: false
-thread 'main' panicked at 'assertion failed: false', $DIR/catch_panic.rs:114:29
+thread 'main' panicked at 'assertion failed: false', $DIR/catch_panic.rs:77:29
 Caught panic message (&str): assertion failed: false
 thread 'main' panicked at 'attempt to copy from unaligned or null pointer', $LOC
 Caught panic message (String): attempt to copy from unaligned or null pointer