Merge branch 'main' of github.com:roc-lang/roc into glue-getters-rtfeldman

crates/compiler/test_gen/src/gen_list.rs

@@ -3493,6 +3493,53 @@ fn reserve_unchanged() {
     );
 }
 
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+fn release_excess_capacity() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            List.reserve [] 15
+            |> List.releaseExcessCapacity
+            "#
+        ),
+        (0, RocList::empty()),
+        RocList<u64>,
+        |value: RocList<u64>| (value.capacity(), value)
+    );
+}
+
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+fn release_excess_capacity_with_len() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            List.reserve [1] 50
+            |> List.releaseExcessCapacity
+            "#
+        ),
+        (1, RocList::from_slice(&[1])),
+        RocList<u64>,
+        |value: RocList<u64>| (value.capacity(), value)
+    );
+}
+
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+fn release_excess_capacity_empty() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            List.releaseExcessCapacity []
+            "#
+        ),
+        (0, RocList::empty()),
+        RocList<u64>,
+        |value: RocList<u64>| (value.capacity(), value)
+    );
+}
+
 #[test]
 #[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
 fn call_function_in_empty_list() {

crates/compiler/test_gen/src/gen_str.rs

@@ -2035,3 +2035,51 @@ fn destructure_pattern_assigned_from_thunk_tag() {
         RocStr
     );
 }
+
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+fn release_excess_capacity() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            Str.reserve "" 50
+            |> Str.releaseExcessCapacity
+            "#
+        ),
+        (RocStr::empty().capacity(), RocStr::empty()),
+        RocStr,
+        |value: RocStr| (value.capacity(), value)
+    );
+}
+
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+fn release_excess_capacity_with_len() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            "123456789012345678901234567890"
+            |> Str.reserve 50
+            |> Str.releaseExcessCapacity
+            "#
+        ),
+        (30, "123456789012345678901234567890".into()),
+        RocStr,
+        |value: RocStr| (value.capacity(), value)
+    );
+}
+
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+fn release_excess_capacity_empty() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            Str.releaseExcessCapacity ""
+            "#
+        ),
+        (RocStr::empty().capacity(), RocStr::empty()),
+        RocStr,
+        |value: RocStr| (value.capacity(), value)
+    );
+}

crates/compiler/test_gen/src/helpers/from_wasm32_memory.rs

@@ -60,7 +60,10 @@ impl FromWasm32Memory for RocStr {
         let str_words: &[u32; 3] = unsafe { std::mem::transmute(&str_bytes) };
 
         let big_elem_ptr = str_words[Builtin::WRAPPER_PTR as usize] as usize;
-        let big_length = str_words[Builtin::WRAPPER_LEN as usize] as usize;
+        // If the str is a seamless slice, it's highest bit will be set to 1.
+        // We need to remove that bit or we will get an incorrect negative length.
+        // Since wasm length is 32bits, and with i32::MAX (0 followed by all 1s in 32 bit).
+        let big_length = str_words[Builtin::WRAPPER_LEN as usize] as usize & (i32::MAX as usize);
         let big_capacity = str_words[Builtin::WRAPPER_CAPACITY as usize] as usize;
 
         let last_byte = str_bytes[11];