Remove bindgen dependency; generate all FFI types from JSON

gdextension_interface.rs is now fully produced by godot-codegen from
gdextension_interface.json, eliminating the C header and bindgen entirely.

Author: Bromeon

Cargo.toml

@@ -24,7 +24,7 @@ rust-version = "1.94"
 # regular dependencies. Sort alphabetically within each section; comments about a dependency come on the section header.
 [workspace.dependencies]
 # Related to godot-rust.
-gdextension-api = { version = "0.3.3", git = "https://github.com/godot-rust/godot4-prebuilt", branch = "release-v0.3" }
+gdextension-api = { version = "0.5.0", git = "https://github.com/godot-rust/godot4-prebuilt", branch = "release-v0.5" }
 
 # Main library features.
 glam = { version = "0.32", features = ["debug-glam-assert"] }
@@ -34,7 +34,6 @@ serde_json = "1"
 # Related to tooling/build setup.
 # * regex: not used for unicode parsing -> features unicode-bool + unicode-gencat are enabled instead of unicode-perl.
 #          'unicode-gencat' needed for \d, see https://docs.rs/regex/latest/regex/#unicode-features.
-bindgen = { version = "0.72.1", default-features = false, features = ["runtime"] }
 libc = "0.2.183"
 regex = { version = "1.12", default-features = false, features = ["std", "unicode-bool", "unicode-gencat"] }
 which = "8"

godot-bindings/Cargo.toml

@@ -28,8 +28,8 @@ api-4-6 = []
 
 default = []
 
-api-custom = ["dep:bindgen", "dep:regex", "dep:which"]
-api-custom-json = ["dep:nanoserde", "dep:bindgen", "dep:regex", "dep:which"]
+api-custom = ["dep:regex", "dep:which"]
+api-custom-json = ["dep:nanoserde", "dep:which"]
 api-custom-extheader = []
 
 # Safeguard levels (see godot/lib.rs for detailed documentation).
@@ -39,7 +39,6 @@ safeguards-release-disengaged = []
 [dependencies]
 gdextension-api = { workspace = true }
 
-bindgen = { workspace = true, optional = true }
 regex = { workspace = true, optional = true }
 which = { workspace = true, optional = true }
 # Required by `api-custom-json` to parse the extension API JSON (to get the Godot version).

godot-bindings/src/godot_exe.rs

@@ -12,10 +12,7 @@ use std::path::{Path, PathBuf};
 use std::process::{Command, Output};
 use std::sync::Once;
 
-use regex::Regex;
-
 use crate::godot_version::{parse_godot_version, validate_godot_version};
-use crate::header_gen::generate_rust_binding;
 use crate::watch::StopWatch;
 use crate::{GodotVersion, env_var_or_deprecated};
 
@@ -51,41 +48,6 @@ pub fn load_gdextension_json(watch: &mut StopWatch) -> String {
     result
 }
 
-pub fn write_gdextension_headers(
-    inout_h_path: &Path,
-    out_rs_path: &Path,
-    is_h_provided: bool,
-    watch: &mut StopWatch,
-) {
-    // Use Godot binary to dump GDExtension headers if they weren't provided by the user.
-    if !is_h_provided {
-        // No external C header file: Godot binary is present, we use it to dump C header
-        let godot_bin = locate_godot_binary();
-        rerun_on_changed(&godot_bin);
-        watch.record("locate_godot");
-
-        // Regenerate API JSON if first time or Godot version is different.
-        // Note: read_godot_version() already panics if 4.0 is still in use; no need to check again.
-        // This also validates whether we run a Debug build.
-        let _version = read_godot_version(&godot_bin);
-
-        // if !c_header_path.exists() || has_version_changed(&version) {
-        dump_header_file(&godot_bin, inout_h_path);
-        // update_version_file(&version);
-        watch.record("dump_header_h");
-        // }
-    };
-
-    // Listening to changes on files that are generated by this build step cause an infinite loop with cargo watch of
-    // build -> detect change -> rebuild -> detect change -> ...
-    // rerun_on_changed(inout_h_path);
-    patch_c_header(inout_h_path, inout_h_path);
-    watch.record("patch_header_h");
-
-    generate_rust_binding(inout_h_path, out_rs_path);
-    watch.record("generate_header_rs");
-}
-
 /*
 fn has_version_changed(current_version: &str) -> bool {
     let version_path = Path::new(GODOT_VERSION_PATH);
@@ -161,67 +123,6 @@ fn dump_extension_api(godot_bin: &Path, out_file: &Path) {
     println!("Generated {}/extension_api.json.", cwd.display());
 }
 
-fn dump_header_file(godot_bin: &Path, out_file: &Path) {
-    let cwd = out_file.parent().unwrap();
-    fs::create_dir_all(cwd).unwrap_or_else(|_| panic!("create directory '{}'", cwd.display()));
-    println!("Dump GDExtension header file to dir '{}'...", cwd.display());
-
-    let mut cmd = Command::new(godot_bin);
-    cmd.current_dir(cwd)
-        .arg("--headless")
-        .arg("--dump-gdextension-interface");
-
-    execute(cmd, "dump Godot header file");
-    println!("Generated {}/gdextension_interface.h.", cwd.display());
-}
-
-pub(crate) fn patch_c_header(in_h_path: &Path, out_h_path: &Path) {
-    // The C header path *must* be passed in by the invoking crate, as the path cannot be relative to this crate.
-    // Otherwise, it can be something like `/home/runner/.cargo/git/checkouts/gdext-76630c89719e160c/efd3b94/godot-bindings`.
-
-    println!("Patch C header '{}'...", in_h_path.display());
-
-    let mut c = fs::read_to_string(in_h_path)
-        .unwrap_or_else(|_| panic!("failed to read C header file {}", in_h_path.display()));
-
-    // Detect whether header is legacy (4.0) format. This should generally already be checked outside.
-    assert!(
-        c.contains("GDExtensionInterfaceGetProcAddress"),
-        "C header file '{}' seems to be GDExtension version 4.0, which is no longer support by godot-rust.",
-        in_h_path.display()
-    );
-
-    // Patch for variant converters and type constructors.
-    c = c.replace(
-        "typedef void (*GDExtensionVariantFromTypeConstructorFunc)(GDExtensionVariantPtr, GDExtensionTypePtr);",
-        "typedef void (*GDExtensionVariantFromTypeConstructorFunc)(GDExtensionUninitializedVariantPtr, GDExtensionTypePtr);"
-    )
-    .replace(
-        "typedef void (*GDExtensionTypeFromVariantConstructorFunc)(GDExtensionTypePtr, GDExtensionVariantPtr);",
-        "typedef void (*GDExtensionTypeFromVariantConstructorFunc)(GDExtensionUninitializedTypePtr, GDExtensionVariantPtr);"
-    )
-    .replace(
-        "typedef void (*GDExtensionPtrConstructor)(GDExtensionTypePtr p_base, const GDExtensionConstTypePtr *p_args);",
-        "typedef void (*GDExtensionPtrConstructor)(GDExtensionUninitializedTypePtr p_base, const GDExtensionConstTypePtr *p_args);"
-    );
-
-    // Use single regex with independent "const"/"Const", as there are definitions like this:
-    // typedef const void *GDExtensionMethodBindPtr;
-    let c = Regex::new(r"typedef (const )?void \*GDExtension(Const)?([a-zA-Z0-9]+?)Ptr;") //
-        .expect("regex for mut typedef")
-        .replace_all(&c, "typedef ${1}struct __Gdext$3 *GDExtension${2}${3}Ptr;");
-
-    // println!("Patched contents:\n\n{}\n\n", c.as_ref());
-
-    // Write the modified contents back to the file
-    fs::write(out_h_path, c.as_ref()).unwrap_or_else(|_| {
-        panic!(
-            "failed to write patched C header file {}",
-            out_h_path.display()
-        )
-    });
-}
-
 pub(crate) fn locate_godot_binary() -> PathBuf {
     static WARN_ONCE: Once = Once::new();
     let env_var = env_var_or_deprecated(&WARN_ONCE, "GDRUST_GODOT_BIN", "GODOT4_BIN");

godot-bindings/src/godot_json.rs

@@ -20,18 +20,8 @@ use std::sync::Once;
 
 use nanoserde::DeJson;
 
-use crate::depend_on_custom_json::header_gen::generate_rust_binding;
 use crate::godot_version::validate_godot_version;
-use crate::{GodotVersion, StopWatch, env_var_or_deprecated};
-
-#[rustfmt::skip] // Do not reorder.
-// GDExtension headers are backward compatible (new incremental changes in general are exposed as additions to the existing API) while godot-rust simply ignores extra declarations in header file.
-// Therefore, latest headers should work fine for all the past and future Godot versions – as long as the engine remains unchanged.
-// [version-sync] [[
-//  [include] current.minor
-//  [line] use gdextension_api::version_$snakeVersion::load_gdextension_header_h as load_latest_gdextension_headers;
-use gdextension_api::version_4_6::load_gdextension_header_h as load_latest_gdextension_headers;
-// ]]
+use crate::{GodotVersion, env_var_or_deprecated};
 
 /// A minimal version of deserialized JsonExtensionApi that includes only the header.
 #[derive(DeJson)]
@@ -97,17 +87,3 @@ pub(crate) fn read_godot_version() -> GodotVersion {
 
     version
 }
-
-pub(crate) fn write_gdextension_headers(
-    out_h_path: &Path,
-    out_rs_path: &Path,
-    watch: &mut StopWatch,
-) {
-    let h_contents = load_latest_gdextension_headers();
-    fs::write(out_h_path, h_contents.as_ref())
-        .unwrap_or_else(|e| panic!("failed to write gdextension_interface.h: {e}"));
-    watch.record("write_header_h");
-
-    generate_rust_binding(out_h_path, out_rs_path);
-    watch.record("generate_header_rs");
-}