Draft: Allows to introspect Python modules from cdylib

pyo3-macros-backend/src/introspection.rs

@@ -91,21 +91,14 @@ pub fn function_introspection_code(pyo3_crate_path: &PyO3CratePath, name: &str)
 }
 
 fn stub_section(content: impl ToTokens) -> TokenStream {
-    if cfg!(target_family = "wasm") {
-        // Sadly WASM only supports in custom sections only static values without references.
-        return quote!();
-    }
-    let section_name = if cfg!(any(target_os = "macos", target_os = "ios")) {
-        "__TEXT,__pyo3i0"
-    } else {
-        ".pyo3i0"
-    };
     let static_name = format_ident!("PYO3_INTRS_{}", unique_element_id());
     // #[no_mangle] is required to make sure some linkers like Linux ones do not mangle the section name too.
     quote! {
         const _: () = {
             #[used]
-            #[link_section = #section_name]
+            #[cfg(not(target_family = "wasm"))]
+            #[cfg_attr(any(target_os = "macos", target_os = "ios", target_os = "tvos", target_os = "watchos"), link_section = "__TEXT,__pyo3i0")]
+            #[cfg_attr(not(any(target_os = "macos", target_os = "ios", target_os = "tvos", target_os = "watchos")), link_section = ".pyo3i0")]
             #[no_mangle]
             static #static_name: &'static str = #content;
         };