Handle @export_file on arrays only available in Godot 4.3+

Also adjust error when #[export(file)] is used on arrays in older versions

Author: Bromeon

godot-bindings/src/lib.rs

@@ -217,20 +217,16 @@ pub fn remove_dir_all_reliable(path: &Path) {
     }
 }
 
-// Duplicates code from `make_gdext_build_struct` in `godot-codegen/generator/gdext_build_struct.rs`.
+/// Concrete check against an API level, not runtime level.
+///
+/// Necessary in `build.rs`, which doesn't itself have the cfgs.
 pub fn before_api(major_minor: &str) -> bool {
-    let mut parts = major_minor.split('.');
-    let queried_major = parts
-        .next()
-        .unwrap()
-        .parse::<u8>()
-        .expect("invalid major version");
-    let queried_minor = parts
-        .next()
-        .unwrap()
-        .parse::<u8>()
-        .expect("invalid minor version");
-    assert_eq!(queried_major, 4, "major version must be 4");
+    let queried_minor = major_minor
+        .strip_prefix("4.")
+        .expect("major version must be 4");
+
+    let queried_minor = queried_minor.parse::<u8>().expect("invalid minor version");
+
     let godot_version = get_godot_version();
     godot_version.minor < queried_minor
 }

godot-core/src/registry/property.rs

@@ -449,7 +449,9 @@ pub mod export_info_functions {
 
             // Array<GString> or PackedStringArray field:
             // { "type": 28, "hint": 23, "hint_string": "4/13:*.png" }
+            #[cfg(since_api = "4.3")]
             VariantType::PACKED_STRING_ARRAY => to_string_array_hint(hint, filter),
+            #[cfg(since_api = "4.3")]
             VariantType::ARRAY if field_ty.is_array_of_elem::<GString>() => {
                 to_string_array_hint(hint, filter)
             }
@@ -460,10 +462,17 @@ pub mod export_info_functions {
 
                 // TODO nicer error handling.
                 // Compile time may be difficult (at least without extra traits... maybe const fn?). But at least more context info, field name etc.
+                #[cfg(since_api = "4.3")]
                 panic!(
                     "#[export({attribute_name})] only supports GString, Array<String> or PackedStringArray field types\n\
                     encountered: {field_ty:?}"
                 );
+
+                #[cfg(before_api = "4.3")]
+                panic!(
+                    "#[export({attribute_name})] only supports GString type prior to Godot 4.3\n\
+                    encountered: {field_ty:?}"
+                );
             }
         }
     }

itest/rust/build.rs

@@ -150,6 +150,7 @@ fn collect_inputs() -> Vec<Input> {
     push!(inputs; PackedStringArray, PackedStringArray, PackedStringArray(), PackedStringArray::new());
     push!(inputs; PackedVector2Array, PackedVector2Array, PackedVector2Array(), PackedVector2Array::new());
     push!(inputs; PackedVector3Array, PackedVector3Array, PackedVector3Array(), PackedVector3Array::new());
+
     // This is being run in a build script at the same time as other build-scripts, so the `rustc-cfg` directives haven't been run for this
     // build-script. This means that `#[cfg(since_api = "4.3")]` wouldn't do anything.
     if godot_bindings::since_api("4.3") {
@@ -214,6 +215,7 @@ fn main() {
         rust: rust_property_tests,
         gdscript: gdscript_property_tests,
     } = generate_property_template(&inputs);
+
     let extras = inputs.iter().map(|input| &input.extra);
 
     let rust_tokens = quote::quote! {
@@ -465,49 +467,63 @@ fn generate_property_template(inputs: &[Input]) -> PropertyTests {
         }
     }
 
-    let rust = quote! {
-        #[derive(GodotClass)]
-        #[class(base = Node, init)]
-        pub struct PropertyTestsRust {
-            #(#rust,)*
-
-            // All the @export_file/dir variants, with GString, Array<GString> and PackedStringArray.
-            #[export(file)]
-            export_file: GString,
+    // Only available in Godot 4.3+.
+    let rust_exports_4_3 = if godot_bindings::before_api("4.3") {
+        TokenStream::new()
+    } else {
+        quote! {
             #[export(file)]
             export_file_array: Array<GString>,
             #[export(file)]
             export_file_parray: PackedStringArray,
-            #[export(file = "*.txt")]
-            export_file_wildcard: GString,
+
             #[export(file = "*.txt")]
             export_file_wildcard_array: Array<GString>,
             #[export(file = "*.txt")]
             export_file_wildcard_parray: PackedStringArray,
-            #[export(global_file)]
-            export_global_file: GString,
+
             #[export(global_file)]
             export_global_file_array: Array<GString>,
             #[export(global_file)]
             export_global_file_parray: PackedStringArray,
-            #[export(global_file = "*.png")]
-            export_global_file_wildcard: GString,
+
             #[export(global_file = "*.png")]
             export_global_file_wildcard_array: Array<GString>,
             #[export(global_file = "*.png")]
             export_global_file_wildcard_parray: PackedStringArray,
-            #[export(dir)]
-            export_dir: GString,
+
             #[export(dir)]
             export_dir_array: Array<GString>,
             #[export(dir)]
             export_dir_parray: PackedStringArray,
-            #[export(global_dir)]
-            export_global_dir: GString,
+
             #[export(global_dir)]
             export_global_dir_array: Array<GString>,
             #[export(global_dir)]
             export_global_dir_parray: PackedStringArray,
+        }
+    };
+
+    let rust = quote! {
+        #[derive(GodotClass)]
+        #[class(base = Node, init)]
+        pub struct PropertyTestsRust {
+            #(#rust,)*
+            #rust_exports_4_3
+
+            // All the @export_file/dir variants, with GString, Array<GString> and PackedStringArray.
+            #[export(file)]
+            export_file: GString,
+            #[export(file = "*.txt")]
+            export_file_wildcard: GString,
+            #[export(global_file)]
+            export_global_file: GString,
+            #[export(global_file = "*.png")]
+            export_global_file_wildcard: GString,
+            #[export(dir)]
+            export_dir: GString,
+            #[export(global_dir)]
+            export_global_dir: GString,
 
             #[export(multiline)]
             export_multiline: GString,
@@ -548,27 +564,16 @@ fn generate_property_template(inputs: &[Input]) -> PropertyTests {
         }
     };
 
-    let gdscript = format!(
-        r#"
-{}
+    // `extends`, basic `var` and `@export var` declarations
+    let basic_exports = gdscript.join("\n");
+
+    let advanced_exports = r#"
 @export_file var export_file: String
-@export_file var export_file_array: Array[String]
-@export_file var export_file_parray: PackedStringArray
 @export_file("*.txt") var export_file_wildcard: String
-@export_file("*.txt") var export_file_wildcard_array: Array[String]
-@export_file("*.txt") var export_file_wildcard_parray: PackedStringArray
 @export_global_file var export_global_file: String
-@export_global_file var export_global_file_array: Array[String]
-@export_global_file var export_global_file_parray: PackedStringArray
 @export_global_file("*.png") var export_global_file_wildcard: String
-@export_global_file("*.png") var export_global_file_wildcard_array: Array[String]
-@export_global_file("*.png") var export_global_file_wildcard_parray: PackedStringArray
 @export_dir var export_dir: String
-@export_dir var export_dir_array: Array[String]
-@export_dir var export_dir_parray: PackedStringArray
 @export_global_dir var export_global_dir: String
-@export_global_dir var export_global_dir_array: Array[String]
-@export_global_dir var export_global_dir_parray: PackedStringArray
 
 @export_multiline var export_multiline: String
 @export_range(0, 20) var export_range_float_0_20: float
@@ -588,9 +593,29 @@ fn generate_property_template(inputs: &[Input]) -> PropertyTests {
 @export_enum("Warrior", "Magician", "Thief") var export_enum_int_warrior_magician_thief: int
 @export_enum("Slow:30", "Average:60", "VeryFast:200") var export_enum_int_slow_30_average_60_very_fast_200: int
 @export_enum("Rebecca", "Mary", "Leah") var export_enum_string_rebecca_mary_leah: String
-"#,
-        gdscript.join("\n")
-    );
+"#;
+
+    // Only available in Godot 4.3+.
+    let advanced_exports_4_3 = r#"
+@export_file var export_file_array: Array[String]
+@export_file var export_file_parray: PackedStringArray
+@export_file("*.txt") var export_file_wildcard_array: Array[String]
+@export_file("*.txt") var export_file_wildcard_parray: PackedStringArray
+@export_global_file var export_global_file_array: Array[String]
+@export_global_file var export_global_file_parray: PackedStringArray
+@export_global_file("*.png") var export_global_file_wildcard_array: Array[String]
+@export_global_file("*.png") var export_global_file_wildcard_parray: PackedStringArray
+@export_dir var export_dir_array: Array[String]
+@export_dir var export_dir_parray: PackedStringArray
+@export_global_dir var export_global_dir_array: Array[String]
+@export_global_dir var export_global_dir_parray: PackedStringArray
+    "#;
+
+    let mut gdscript = format!("{basic_exports}\n{advanced_exports}");
+    if godot_bindings::since_api("4.3") {
+        gdscript.push('\n');
+        gdscript.push_str(advanced_exports_4_3);
+    }
 
     PropertyTests { rust, gdscript }
 }

itest/rust/src/object_tests/property_template_test.rs

@@ -44,6 +44,16 @@ fn property_template_test(ctx: &TestContext) {
             continue;
         }
 
+        // Skip @export_file and similar properties for Array<GString> and PackedStringArray (only supported in Godot 4.3+).
+        // Here, we use API and not runtime level, because inclusion/exclusion of GDScript code is determined at build time in godot-bindings.
+        //
+        // Name can start in `export_file`, `export_global_file`, `export_dir`, `export_global_dir`.
+        // Can end in either `_array` or `_parray`.
+        #[cfg(before_api = "4.3")]
+        if (name.contains("_file_") || name.contains("_dir_")) && name.ends_with("array") {
+            continue;
+        }
+
         if name.starts_with("var_") || name.starts_with("export_") {
             properties.insert(name, property);
         }