Rollup merge of #67119 - RalfJung:miri-test-libstd, r=alexcrichton

libstd miri tests: avoid warnings

Ignore tests in a way that all the code still gets compiled, to get rid of all the "unused" warnings that otherwise show up when running the test suite in Miri.

Author: tmandry

src/liballoc/alloc/tests.rs

@@ -22,7 +22,7 @@ fn allocate_zeroed() {
 }
 
 #[bench]
-#[cfg(not(miri))] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
 fn alloc_owned_small(b: &mut Bencher) {
     b.iter(|| {
         let _: Box<_> = box 10;

src/liballoc/collections/linked_list/tests.rs

@@ -182,7 +182,7 @@ fn test_insert_prev() {
 
 #[test]
 #[cfg_attr(target_os = "emscripten", ignore)]
-#[cfg(not(miri))] // Miri does not support threads
+#[cfg_attr(miri, ignore)] // Miri does not support threads
 fn test_send() {
     let n = list_from(&[1, 2, 3]);
     thread::spawn(move || {

src/liballoc/collections/vec_deque/tests.rs

@@ -3,7 +3,7 @@ use super::*;
 use ::test;
 
 #[bench]
-#[cfg(not(miri))] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
 fn bench_push_back_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::with_capacity(101);
     b.iter(|| {
@@ -16,7 +16,7 @@ fn bench_push_back_100(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg(not(miri))] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
 fn bench_push_front_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::with_capacity(101);
     b.iter(|| {
@@ -29,7 +29,7 @@ fn bench_push_front_100(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg(not(miri))] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
 fn bench_pop_back_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::<i32>::with_capacity(101);
 
@@ -43,7 +43,7 @@ fn bench_pop_back_100(b: &mut test::Bencher) {
 }
 
 #[bench]
-#[cfg(not(miri))] // Miri does not support benchmarks
+#[cfg_attr(miri, ignore)] // Miri does not support benchmarks
 fn bench_pop_front_100(b: &mut test::Bencher) {
     let mut deq = VecDeque::<i32>::with_capacity(101);
 

src/liballoc/sync/tests.rs

@@ -29,7 +29,7 @@ impl Drop for Canary {
 
 #[test]
 #[cfg_attr(target_os = "emscripten", ignore)]
-#[cfg(not(miri))] // Miri does not support threads
+#[cfg_attr(miri, ignore)] // Miri does not support threads
 fn manually_share_arc() {
     let v = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
     let arc_v = Arc::new(v);
@@ -334,7 +334,7 @@ fn test_ptr_eq() {
 
 #[test]
 #[cfg_attr(target_os = "emscripten", ignore)]
-#[cfg(not(miri))] // Miri does not support threads
+#[cfg_attr(miri, ignore)] // Miri does not support threads
 fn test_weak_count_locked() {
     let mut a = Arc::new(atomic::AtomicBool::new(false));
     let a2 = a.clone();

src/liballoc/tests/slice.rs

@@ -388,7 +388,7 @@ fn test_reverse() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn test_sort() {
     let mut rng = thread_rng();
 
@@ -1610,7 +1610,7 @@ fn panic_safe() {
     let moduli = &[5, 20, 50];
 
     #[cfg(miri)]
-    let lens = (1..13);
+    let lens = 1..13;
     #[cfg(miri)]
     let moduli = &[10];
 

src/liballoc/tests/str.rs

@@ -166,7 +166,7 @@ fn test_join_for_different_lengths_with_long_separator() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn test_unsafe_slice() {
     assert_eq!("ab", unsafe {"abc".get_unchecked(0..2)});
     assert_eq!("bc", unsafe {"abc".get_unchecked(1..3)});
@@ -483,8 +483,8 @@ mod slice_index {
     }
 
     #[test]
-    #[cfg(not(target_os = "emscripten"))] // hits an OOM
-    #[cfg(not(miri))] // Miri is too slow
+    #[cfg_attr(target_os = "emscripten", ignore)] // hits an OOM
+    #[cfg_attr(miri, ignore)] // Miri is too slow
     fn simple_big() {
         fn a_million_letter_x() -> String {
             let mut i = 0;
@@ -1069,7 +1069,7 @@ fn test_rev_iterator() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn test_chars_decoding() {
     let mut bytes = [0; 4];
     for c in (0..0x110000).filter_map(std::char::from_u32) {
@@ -1081,7 +1081,7 @@ fn test_chars_decoding() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn test_chars_rev_decoding() {
     let mut bytes = [0; 4];
     for c in (0..0x110000).filter_map(std::char::from_u32) {
@@ -1380,7 +1380,6 @@ fn test_bool_from_str() {
     assert_eq!("not even a boolean".parse::<bool>().ok(), None);
 }
 
-#[cfg(not(miri))] // Miri is too slow
 fn check_contains_all_substrings(s: &str) {
     assert!(s.contains(""));
     for i in 0..s.len() {
@@ -1391,7 +1390,7 @@ fn check_contains_all_substrings(s: &str) {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn strslice_issue_16589() {
     assert!("bananas".contains("nana"));
 
@@ -1408,7 +1407,7 @@ fn strslice_issue_16878() {
 
 
 #[test]
-#[cfg(not(miri))] // Miri is too slow
+#[cfg_attr(miri, ignore)] // Miri is too slow
 fn test_strslice_contains() {
     let x = "There are moments, Jeeves, when one asks oneself, 'Do trousers matter?'";
     check_contains_all_substrings(x);

src/liballoc/tests/string.rs

@@ -523,7 +523,7 @@ fn test_reserve_exact() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not support signalling OOM
+#[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
 fn test_try_reserve() {
 
     // These are the interesting cases:
@@ -601,7 +601,7 @@ fn test_try_reserve() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not support signalling OOM
+#[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
 fn test_try_reserve_exact() {
 
     // This is exactly the same as test_try_reserve with the method changed.

src/liballoc/tests/vec.rs

@@ -1080,7 +1080,7 @@ fn test_reserve_exact() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not support signalling OOM
+#[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
 fn test_try_reserve() {
 
     // These are the interesting cases:
@@ -1183,7 +1183,7 @@ fn test_try_reserve() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not support signalling OOM
+#[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
 fn test_try_reserve_exact() {
 
     // This is exactly the same as test_try_reserve with the method changed.

src/liballoc/tests/vec_deque.rs

@@ -1100,7 +1100,7 @@ fn test_reserve_exact_2() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not support signalling OOM
+#[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
 fn test_try_reserve() {
     // These are the interesting cases:
     // * exactly isize::MAX should never trigger a CapacityOverflow (can be OOM)
@@ -1214,7 +1214,7 @@ fn test_try_reserve() {
 }
 
 #[test]
-#[cfg(not(miri))] // Miri does not support signalling OOM
+#[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
 fn test_try_reserve_exact() {
     // This is exactly the same as test_try_reserve with the method changed.
     // See that test for comments.

src/libcore/tests/hash/mod.rs

@@ -71,14 +71,16 @@ fn test_writer_hasher() {
     let ptr = 5_usize as *mut i32;
     assert_eq!(hash(&ptr), 5);
 
+    if cfg!(miri) { // Miri cannot hash pointers
+        return;
+    }
+
     let cs: &mut [u8] = &mut [1, 2, 3];
     let ptr = cs.as_ptr();
     let slice_ptr = cs as *const [u8];
-    #[cfg(not(miri))] // Miri cannot hash pointers
     assert_eq!(hash(&slice_ptr), hash(&ptr) + cs.len() as u64);
 
     let slice_ptr = cs as *mut [u8];
-    #[cfg(not(miri))] // Miri cannot hash pointers
     assert_eq!(hash(&slice_ptr), hash(&ptr) + cs.len() as u64);
 }
 

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

@@ -31,7 +31,11 @@ fn ordinary() {
     test_literal!(0.1);
     test_literal!(12345.);
     test_literal!(0.9999999);
-    #[cfg(not(miri))] // Miri is too slow
+
+    if cfg!(miri) { // Miri is too slow
+        return;
+    }
+
     test_literal!(2.2250738585072014e-308);
 }
 
@@ -53,7 +57,7 @@ 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 +69,7 @@ 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);
@@ -77,9 +81,12 @@ fn infinity() {
 fn zero() {
     test_literal!(0.0);
     test_literal!(1e-325);
-    #[cfg(not(miri))] // Miri is too slow
+
+    if cfg!(miri) { // Miri is too slow
+        return;
+    }
+
     test_literal!(1e-326);
-    #[cfg(not(miri))] // Miri is too slow
     test_literal!(1e-500);
 }
 

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

@@ -41,7 +41,7 @@ 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

@@ -289,7 +289,7 @@ 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.
@@ -304,7 +304,7 @@ 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.
@@ -326,7 +326,7 @@ 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

@@ -1183,7 +1183,7 @@ 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;
@@ -1302,7 +1302,7 @@ 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;
@@ -1505,7 +1505,7 @@ 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>() };
@@ -1535,7 +1535,7 @@ 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);