Port fuzzer changes from PR #737 to v1

.github/workflows/fuzzing.yml

@@ -23,10 +23,7 @@ jobs:
       - name: fuzz
         run: |
           cargo install cargo-fuzz
-          set -e
-          for i in {1..6}; do
-            cargo fuzz run main -- -max_total_time=300 -rss_limit_mb=4096
-          done
+          cargo fuzz run main -- -max_total_time=1800 -rss_limit_mb=4096
       - name: minimize corpus
         if: always()
         run: cargo fuzz cmin main

fuzz/fuzz_targets/main.rs

@@ -4,6 +4,9 @@
 
 use {arbitrary::Arbitrary, libfuzzer_sys::fuzz_target, smallvec::SmallVec, std::fmt::Debug};
 
+// Upper bound on the harness's test vectors's capacity.
+const MAX_CAP: usize = 1024;
+
 /// A generic wrapper that bounds data generated via `arbitrary`.
 /// Default cap is 255.
 #[derive(Debug, Clone)]
@@ -47,8 +50,8 @@ enum Op {
     New,
     WithCapacity(Bounded<usize>),
     FromVec,
-    FromSlice(Bounded<Vec<usize>>),
-    Push(usize),
+    FromSlice(Bounded<Vec<u64>>),
+    Push(u64),
     Pop,
     Grow(Bounded<usize>),
     Reserve(Bounded<usize>),
@@ -58,12 +61,12 @@ enum Op {
     SwapRemove,
     Clear,
     Remove,
-    Insert(usize),
+    Insert(u64),
     Drain,
     RetainEven,
     Dedup,
-    ExtendFromSlice(Bounded<Vec<usize>>),
-    Resize(Bounded<usize>, usize),
+    ExtendFromSlice(Bounded<Vec<u64>>),
+    Resize(Bounded<usize>, u64),
 }
 
 /// Helper to assert equivalence of all structural invariants of `SmallVec`
@@ -135,12 +138,12 @@ fn test_with_inline_cap<const N: usize>(
     u: &mut arbitrary::Unstructured,
     ops: &[Op],
 ) -> arbitrary::Result<()> {
-    // We let `T` be `usize` instead of `u8` because, albeit less efficient,
+    // We let `T` be `u64` instead of `u8` because, albeit less efficient,
     // this incurs potential memory misalignment which should be properly
     // handled by the library.
 
-    let mut small_vec = SmallVec::<[usize; N]>::new();
-    let mut std_vec = Vec::<usize>::new();
+    let mut small_vec = SmallVec::<[u64; N]>::new();
+    let mut std_vec = Vec::<u64>::new();
 
     for op in ops {
         match op {
@@ -251,6 +254,13 @@ fn test_with_inline_cap<const N: usize>(
             }
         }
 
+        if small_vec.capacity() > MAX_CAP {
+            small_vec.truncate(MAX_CAP);
+            std_vec.truncate(MAX_CAP);
+            small_vec.shrink_to_fit();
+            std_vec.shrink_to_fit();
+        }
+
         assert_invariants(&mut small_vec, &mut std_vec);
     }
 
@@ -261,7 +271,7 @@ fn run_test(mut u: arbitrary::Unstructured) -> arbitrary::Result<()> {
     let ops = Vec::<Op>::arbitrary(&mut u)?;
     let dynamic_entropy = u.take_rest();
 
-    let run_test = |test_func: fn(&mut arbitrary::Unstructured, &[Op]) -> arbitrary::Result<()>| {
+    let run_test = |test_func: fn(&mut arbitrary::Unstructured, &[Op]) -> _| {
         test_func(&mut arbitrary::Unstructured::new(dynamic_entropy), &ops)
     };