libcore: ignore tests in Miri instead of removing them entirely

src/libcore/tests/num/dec2flt/mod.rs

@@ -53,7 +53,7 @@ fn large() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn subnormals() {
     test_literal!(5e-324);
     test_literal!(91e-324);
@@ -65,7 +65,7 @@ fn subnormals() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn infinity() {
     test_literal!(1e400);
     test_literal!(1e309);

src/libcore/tests/num/flt2dec/mod.rs

@@ -256,7 +256,6 @@ pub fn f32_shortest_sanity_test<F>(mut f: F) where F: FnMut(&Decoded, &mut [u8])
     check_shortest!(f(minf32) => b"1", -44);
 }
 
-#[cfg(not(miri))] // Miri is too slow
 pub fn f32_exact_sanity_test<F>(mut f: F)
         where F: FnMut(&Decoded, &mut [u8], i16) -> (usize, i16) {
     let minf32 = ldexp_f32(1.0, -149);
@@ -362,7 +361,6 @@ pub fn f64_shortest_sanity_test<F>(mut f: F) where F: FnMut(&Decoded, &mut [u8])
     check_shortest!(f(minf64) => b"5", -323);
 }
 
-#[cfg(not(miri))] // Miri is too slow
 pub fn f64_exact_sanity_test<F>(mut f: F)
         where F: FnMut(&Decoded, &mut [u8], i16) -> (usize, i16) {
     let minf64 = ldexp_f64(1.0, -1074);

src/libcore/tests/num/flt2dec/strategy/dragon.rs

@@ -22,7 +22,7 @@ fn shortest_sanity_test() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn exact_sanity_test() {
     // This test ends up running what I can only assume is some corner-ish case
     // of the `exp2` library function, defined in whatever C runtime we're

src/libcore/tests/num/flt2dec/strategy/grisu.rs

@@ -36,7 +36,7 @@ fn shortest_sanity_test() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn exact_sanity_test() {
     // See comments in dragon.rs's exact_sanity_test for why this test is
     // ignored on MSVC

src/libcore/tests/ptr.rs

@@ -291,7 +291,7 @@ fn write_unaligned_drop() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not compute a maximal `mid` for `align_offset`
+#[cfg_attr(miri, ignore)] // Miri does not compute a maximal `mid` for `align_offset`
 fn align_offset_zst() {
     // For pointers of stride = 0, the pointer is already aligned or it cannot be aligned at
     // all, because no amount of elements will align the pointer.
@@ -306,7 +306,7 @@ fn align_offset_zst() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not compute a maximal `mid` for `align_offset`
+#[cfg_attr(miri, ignore)] // Miri does not compute a maximal `mid` for `align_offset`
 fn align_offset_stride1() {
     // For pointers of stride = 1, the pointer can always be aligned. The offset is equal to
     // number of bytes.
@@ -323,7 +323,7 @@ fn align_offset_stride1() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn align_offset_weird_strides() {
     #[repr(packed)]
     struct A3(u16, u8);

src/libcore/tests/slice.rs

@@ -1172,7 +1172,7 @@ fn test_rotate_right() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn brute_force_rotate_test_0() {
     // In case of edge cases involving multiple algorithms
     let n = 300;
@@ -1291,7 +1291,7 @@ fn sort_unstable() {
 
 #[test]
 #[cfg(not(target_arch = "wasm32"))]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn partition_at_index() {
     use core::cmp::Ordering::{Equal, Greater, Less};
     use rand::rngs::StdRng;
@@ -1494,7 +1494,7 @@ pub mod memchr {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not compute a maximal `mid` for `align_offset`
+#[cfg_attr(miri, ignore)] // Miri does not compute a maximal `mid` for `align_offset`
 fn test_align_to_simple() {
     let bytes = [1u8, 2, 3, 4, 5, 6, 7];
     let (prefix, aligned, suffix) = unsafe { bytes.align_to::<u16>() };
@@ -1518,7 +1518,7 @@ fn test_align_to_zst() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not compute a maximal `mid` for `align_offset`
+#[cfg_attr(miri, ignore)] // Miri does not compute a maximal `mid` for `align_offset`
 fn test_align_to_non_trivial() {
     #[repr(align(8))] struct U64(u64, u64);
     #[repr(align(8))] struct U64U64U32(u64, u64, u32);