share some code between panic intrinsics, and fix the message

Author: RalfJung

src/shims/intrinsics.rs

@@ -444,35 +444,20 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 this.write_scalar(result_ptr, dest)?;
             }
 
-            "panic_if_uninhabited" => {
+            "panic_if_uninhabited" |
+            "panic_if_zero_invalid" |
+            "panic_if_any_invalid" => {
                 let ty = substs.type_at(0);
                 let layout = this.layout_of(ty)?;
                 if layout.abi.is_uninhabited() {
                     // Return here because we paniced instead of returning normally from the intrinsic.
-                    return this.start_panic(&format!("attempted to instantiate uninhabited type {}", ty), unwind);
+                    return this.start_panic(&format!("attempted to instantiate uninhabited type `{}`", ty), unwind);
                 }
-            }
-
-            "panic_if_zero_invalid" => {
-                let ty = substs.type_at(0);
-                let layout = this.layout_of(ty)?;
-                // Check if it permits zeroed raw initialization
-                if !layout.might_permit_raw_init(this, /*zero:*/ true).unwrap() {
+                if intrinsic_name == "panic_if_zero_invalid" && !layout.might_permit_raw_init(this, /*zero:*/ true).unwrap() {
                     // Return here because we paniced instead of returning normally from the intrinsic.
                     return this.start_panic(&format!("attempted to zero-initialize type `{}`, which is invalid", ty), unwind);
                 }
-            }
-
-            "panic_if_any_invalid" => {
-                let ty = substs.type_at(0);
-                let layout = this.layout_of(ty)?;
-                // rustc handles all these in a single function, but we don't so we need to make sure `mem::uninitialized::<!>()` returns the right error.
-                // So we check for `is_uninhabited` here too.
-                if layout.abi.is_uninhabited() {
-                    return this.start_panic(&format!("attempted to instantiate uninhabited type {}", ty), unwind);
-                }
-                // Check if it permits any raw initialization
-                if !layout.might_permit_raw_init(this, /*zero:*/ false).unwrap() {
+                if intrinsic_name == "panic_if_any_invalid" && !layout.might_permit_raw_init(this, /*zero:*/ false).unwrap() {
                     // Return here because we paniced instead of returning normally from the intrinsic.
                     return this.start_panic(&format!("attempted to leave type `{}` uninitialized, which is invalid", ty), unwind);
                 }

tests/run-pass/panic/catch_panic.rs

@@ -71,11 +71,11 @@ fn main() {
     #[allow(deprecated, invalid_value)]
     {
         test(
-            Some("attempted to instantiate uninhabited type !"),
+            Some("attempted to instantiate uninhabited type `!`"),
             |_old_val| unsafe { std::mem::uninitialized::<!>() },
         );
         test(
-            Some("attempted to zero-initialize type `!`, which is invalid"),
+            Some("attempted to instantiate uninhabited type `!`"),
             |_old_val| unsafe { std::mem::zeroed::<!>() },
         );
         test(

tests/run-pass/panic/catch_panic.stderr

@@ -16,10 +16,10 @@ 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 zero-initialize type `!`, which is invalid', $LOC
-Caught panic message (String): attempted to zero-initialize type `!`, which is invalid
+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