Rollup merge of #71476 - RalfJung:miri-test-sizes, r=kennytm

more compact way to adjust test sizes for Miri

Inspired by @dtolnay

src/liballoc/collections/vec_deque/tests.rs

@@ -386,10 +386,8 @@ fn test_vec_from_vecdeque() {
         assert!(vec.into_iter().eq(vd));
     }
 
-    #[cfg(not(miri))] // Miri is too slow
-    let max_pwr = 7;
-    #[cfg(miri)]
-    let max_pwr = 5;
+    // Miri is too slow
+    let max_pwr = if cfg!(miri) { 5 } else { 7 };
 
     for cap_pwr in 0..max_pwr {
         // Make capacity as a (2^x)-1, so that the ring size is 2^x

src/liballoc/tests/binary_heap.rs

@@ -409,16 +409,14 @@ fn panic_safe() {
     }
     let mut rng = thread_rng();
     const DATASZ: usize = 32;
-    #[cfg(not(miri))] // Miri is too slow
-    const NTEST: usize = 10;
-    #[cfg(miri)]
-    const NTEST: usize = 1;
+    // Miri is too slow
+    let ntest = if cfg!(miri) { 1 } else { 10 };
 
     // don't use 0 in the data -- we want to catch the zeroed-out case.
     let data = (1..=DATASZ).collect::<Vec<_>>();
 
     // since it's a fuzzy test, run several tries.
-    for _ in 0..NTEST {
+    for _ in 0..ntest {
         for i in 1..=DATASZ {
             DROP_COUNTER.store(0, Ordering::SeqCst);
 

src/liballoc/tests/btree/map.rs

@@ -28,10 +28,8 @@ const MIN_INSERTS_HEIGHT_2: usize = NODE_CAPACITY + (NODE_CAPACITY + 1) * NODE_C
 #[test]
 fn test_basic_large() {
     let mut map = BTreeMap::new();
-    #[cfg(not(miri))] // Miri is too slow
-    let size = 10000;
-    #[cfg(miri)]
-    let size = MIN_INSERTS_HEIGHT_2;
+    // Miri is too slow
+    let size = if cfg!(miri) { MIN_INSERTS_HEIGHT_2 } else { 10000 };
     assert_eq!(map.len(), 0);
 
     for i in 0..size {
@@ -155,10 +153,8 @@ fn test_basic_small() {
 
 #[test]
 fn test_iter() {
-    #[cfg(not(miri))] // Miri is too slow
-    let size = 10000;
-    #[cfg(miri)]
-    let size = 200;
+    // Miri is too slow
+    let size = if cfg!(miri) { 200 } else { 10000 };
 
     let mut map: BTreeMap<_, _> = (0..size).map(|i| (i, i)).collect();
 
@@ -180,10 +176,8 @@ fn test_iter() {
 
 #[test]
 fn test_iter_rev() {
-    #[cfg(not(miri))] // Miri is too slow
-    let size = 10000;
-    #[cfg(miri)]
-    let size = 200;
+    // Miri is too slow
+    let size = if cfg!(miri) { 200 } else { 10000 };
 
     let mut map: BTreeMap<_, _> = (0..size).map(|i| (i, i)).collect();
 
@@ -289,10 +283,8 @@ fn test_values_mut() {
 
 #[test]
 fn test_iter_mixed() {
-    #[cfg(not(miri))] // Miri is too slow
-    let size = 10000;
-    #[cfg(miri)]
-    let size = 200;
+    // Miri is too slow
+    let size = if cfg!(miri) { 200 } else { 10000 };
 
     let mut map: BTreeMap<_, _> = (0..size).map(|i| (i, i)).collect();
 
@@ -525,10 +517,8 @@ fn test_range_backwards_4() {
 
 #[test]
 fn test_range_1000() {
-    #[cfg(not(miri))] // Miri is too slow
-    let size = 1000;
-    #[cfg(miri)]
-    let size = MIN_INSERTS_HEIGHT_2 as u32;
+    // Miri is too slow
+    let size = if cfg!(miri) { MIN_INSERTS_HEIGHT_2 as u32 } else { 1000 };
     let map: BTreeMap<_, _> = (0..size).map(|i| (i, i)).collect();
 
     fn test(map: &BTreeMap<u32, u32>, size: u32, min: Bound<&u32>, max: Bound<&u32>) {
@@ -566,10 +556,8 @@ fn test_range_borrowed_key() {
 #[test]
 fn test_range() {
     let size = 200;
-    #[cfg(not(miri))] // Miri is too slow
-    let step = 1;
-    #[cfg(miri)]
-    let step = 66;
+    // Miri is too slow
+    let step = if cfg!(miri) { 66 } else { 1 };
     let map: BTreeMap<_, _> = (0..size).map(|i| (i, i)).collect();
 
     for i in (0..size).step_by(step) {
@@ -589,10 +577,8 @@ fn test_range() {
 #[test]
 fn test_range_mut() {
     let size = 200;
-    #[cfg(not(miri))] // Miri is too slow
-    let step = 1;
-    #[cfg(miri)]
-    let step = 66;
+    // Miri is too slow
+    let step = if cfg!(miri) { 66 } else { 1 };
     let mut map: BTreeMap<_, _> = (0..size).map(|i| (i, i)).collect();
 
     for i in (0..size).step_by(step) {
@@ -1263,10 +1249,8 @@ fn test_split_off_empty_left() {
 
 #[test]
 fn test_split_off_large_random_sorted() {
-    #[cfg(not(miri))] // Miri is too slow
-    let mut data = rand_data(1529);
-    #[cfg(miri)]
-    let mut data = rand_data(529);
+    // Miri is too slow
+    let mut data = if cfg!(miri) { rand_data(529) } else { rand_data(1529) };
     // special case with maximum height.
     data.sort();
 

src/liballoc/tests/btree/set.rs

@@ -621,10 +621,8 @@ fn test_split_off_empty_left() {
 
 #[test]
 fn test_split_off_large_random_sorted() {
-    #[cfg(not(miri))] // Miri is too slow
-    let mut data = rand_data(1529);
-    #[cfg(miri)]
-    let mut data = rand_data(529);
+    // Miri is too slow
+    let mut data = if cfg!(miri) { rand_data(529) } else { rand_data(1529) };
     // special case with maximum height.
     data.sort();
 

src/liballoc/tests/slice.rs

@@ -463,15 +463,9 @@ fn test_sort() {
 
 #[test]
 fn test_sort_stability() {
-    #[cfg(not(miri))] // Miri is too slow
-    let large_range = 500..510;
-    #[cfg(not(miri))] // Miri is too slow
-    let rounds = 10;
-
-    #[cfg(miri)]
-    let large_range = 0..0; // empty range
-    #[cfg(miri)]
-    let rounds = 1;
+    // Miri is too slow
+    let large_range = if cfg!(miri) { 0..0 } else { 500..510 };
+    let rounds = if cfg!(miri) { 1 } else { 10 };
 
     for len in (2..25).chain(large_range) {
         for _ in 0..rounds {
@@ -1727,15 +1721,9 @@ fn panic_safe() {
 
     let mut rng = thread_rng();
 
-    #[cfg(not(miri))] // Miri is too slow
-    let lens = (1..20).chain(70..MAX_LEN);
-    #[cfg(not(miri))] // Miri is too slow
-    let moduli = &[5, 20, 50];
-
-    #[cfg(miri)]
-    let lens = 1..10;
-    #[cfg(miri)]
-    let moduli = &[5];
+    // Miri is too slow
+    let lens = if cfg!(miri) { (1..10).chain(20..21) } else { (1..20).chain(70..MAX_LEN) };
+    let moduli: &[u32] = if cfg!(miri) { &[5] } else { &[5, 20, 50] };
 
     for len in lens {
         for &modulus in moduli {

src/liballoc/tests/vec_deque.rs

@@ -954,16 +954,14 @@ fn test_append_permutations() {
         out
     }
 
-    #[cfg(not(miri))] // Miri is too slow
-    const MAX: usize = 5;
-    #[cfg(miri)]
-    const MAX: usize = 3;
+    // Miri is too slow
+    let max = if cfg!(miri) { 3 } else { 5 };
 
     // Many different permutations of both the `VecDeque` getting appended to
     // and the one getting appended are generated to check `append`.
     // This ensures all 6 code paths of `append` are tested.
-    for src_push_back in 0..MAX {
-        for src_push_front in 0..MAX {
+    for src_push_back in 0..max {
+        for src_push_front in 0..max {
             // doesn't pop more values than are pushed
             for src_pop_back in 0..(src_push_back + src_push_front) {
                 for src_pop_front in 0..(src_push_back + src_push_front - src_pop_back) {
@@ -974,8 +972,8 @@ fn test_append_permutations() {
                         src_pop_front,
                     );
 
-                    for dst_push_back in 0..MAX {
-                        for dst_push_front in 0..MAX {
+                    for dst_push_back in 0..max {
+                        for dst_push_front in 0..max {
                             for dst_pop_back in 0..(dst_push_back + dst_push_front) {
                                 for dst_pop_front in
                                     0..(dst_push_back + dst_push_front - dst_pop_back)

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

@@ -52,12 +52,10 @@ fn test_estimate_scaling_factor() {
     assert_almost_eq!(estimate_scaling_factor(1, -1074), -323);
     assert_almost_eq!(estimate_scaling_factor(0x1fffffffffffff, 971), 309);
 
-    #[cfg(not(miri))] // Miri is too slow
-    let iter = -1074..972;
-    #[cfg(miri)]
-    let iter = (-1074..972).step_by(37);
+    // Miri is too slow
+    let step = if cfg!(miri) { 37 } else { 1 };
 
-    for i in iter {
+    for i in (-1074..972).step_by(step) {
         let expected = super::ldexp_f64(1.0, i).log10().ceil();
         assert_almost_eq!(estimate_scaling_factor(1, i as i16), expected as i16);
     }

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

@@ -138,13 +138,11 @@ where
 #[test]
 fn shortest_random_equivalence_test() {
     use core::num::flt2dec::strategy::dragon::format_shortest as fallback;
-    #[cfg(not(miri))] // Miri is too slow
-    const N: usize = 10_000;
-    #[cfg(miri)]
-    const N: usize = 10;
+    // Miri is too slow
+    let n = if cfg!(miri) { 10 } else { 10_000 };
 
-    f64_random_equivalence_test(format_shortest_opt, fallback, MAX_SIG_DIGITS, N);
-    f32_random_equivalence_test(format_shortest_opt, fallback, MAX_SIG_DIGITS, N);
+    f64_random_equivalence_test(format_shortest_opt, fallback, MAX_SIG_DIGITS, n);
+    f32_random_equivalence_test(format_shortest_opt, fallback, MAX_SIG_DIGITS, n);
 }
 
 #[test]
@@ -173,35 +171,31 @@ fn shortest_f64_hard_random_equivalence_test() {
 #[test]
 fn exact_f32_random_equivalence_test() {
     use core::num::flt2dec::strategy::dragon::format_exact as fallback;
-    #[cfg(not(miri))] // Miri is too slow
-    const N: usize = 1_000;
-    #[cfg(miri)]
-    const N: usize = 3;
+    // Miri is too slow
+    let n = if cfg!(miri) { 3 } else { 1_000 };
 
     for k in 1..21 {
         f32_random_equivalence_test(
             |d, buf| format_exact_opt(d, buf, i16::MIN),
             |d, buf| fallback(d, buf, i16::MIN),
             k,
-            N,
+            n,
         );
     }
 }
 
 #[test]
 fn exact_f64_random_equivalence_test() {
     use core::num::flt2dec::strategy::dragon::format_exact as fallback;
-    #[cfg(not(miri))] // Miri is too slow
-    const N: usize = 1_000;
-    #[cfg(miri)]
-    const N: usize = 3;
+    // Miri is too slow
+    let n = if cfg!(miri) { 3 } else { 1_000 };
 
     for k in 1..21 {
         f64_random_equivalence_test(
             |d, buf| format_exact_opt(d, buf, i16::MIN),
             |d, buf| fallback(d, buf, i16::MIN),
             k,
-            N,
+            n,
         );
     }
 }

src/libcore/tests/slice.rs

@@ -1227,15 +1227,9 @@ fn sort_unstable() {
     use core::slice::heapsort;
     use rand::{rngs::StdRng, seq::SliceRandom, Rng, SeedableRng};
 
-    #[cfg(not(miri))] // Miri is too slow
-    let large_range = 500..510;
-    #[cfg(not(miri))] // Miri is too slow
-    let rounds = 100;
-
-    #[cfg(miri)]
-    let large_range = 0..0; // empty range
-    #[cfg(miri)]
-    let rounds = 1;
+    // Miri is too slow
+    let large_range = if cfg!(miri) { 0..0 } else { 500..510 };
+    let rounds = if cfg!(miri) { 1 } else { 100 };
 
     let mut v = [0; 600];
     let mut tmp = [0; 600];