Bring the PyArray_* allocation functions back conditionally based on the enabled PyO3 features.

Author: adamreichold

Cargo.toml

@@ -21,6 +21,9 @@ num-traits = "0.2"
 ndarray = ">= 0.13, < 0.16"
 pyo3 = { version = "0.16", default-features = false }
 
+[build-dependencies]
+pyo3-build-config = "0.16"
+
 [dev-dependencies]
 pyo3 = { version = "0.16", features = ["auto-initialize"] }
 

build.rs

@@ -0,0 +1,5 @@
+use pyo3_build_config::use_pyo3_cfgs;
+
+fn main() {
+    use_pyo3_cfgs();
+}

src/npyffi/array.rs

@@ -394,6 +394,13 @@ pub unsafe fn PyArray_CheckExact(py: Python, op: *mut PyObject) -> c_int {
     (ffi::Py_TYPE(op) == PY_ARRAY_API.get_type_object(py, NpyTypes::PyArray_Type)) as _
 }
 
+// these are under `#if NPY_USE_PYMEM == 1` which seems to be always defined as 1
+#[cfg(not(Py_LIMITED_API))]
+pub use pyo3::ffi::{
+    PyMem_RawFree as PyArray_free, PyMem_RawMalloc as PyArray_malloc,
+    PyMem_RawRealloc as PyArray_realloc,
+};
+
 #[cfg(test)]
 mod tests {
     use super::PY_ARRAY_API;