git.sesse.net Git - bcachefs-tools-debian/blob - bch_bindgen/build.rs

   1 #[derive(Debug)]
   2 pub struct Fix753 {}
   3 impl bindgen::callbacks::ParseCallbacks for Fix753 {
   4     fn item_name(&self, original_item_name: &str) -> Option<String> {
   5         Some(original_item_name.trim_start_matches("Fix753_").to_owned())
   6     }
   7 }
   8
   9 fn main() {
  10     use std::path::PathBuf;
  11
  12     println!("cargo:rerun-if-changed=src/libbcachefs_wrapper.h");
  13
  14     let out_dir: PathBuf = std::env::var_os("OUT_DIR")
  15         .expect("ENV Var 'OUT_DIR' Expected")
  16         .into();
  17     let top_dir: PathBuf = std::env::var_os("CARGO_MANIFEST_DIR")
  18         .expect("ENV Var 'CARGO_MANIFEST_DIR' Expected")
  19         .into();
  20
  21     let urcu = pkg_config::probe_library("liburcu").expect("Failed to find urcu lib");
  22     let bindings = bindgen::builder()
  23         .formatter(bindgen::Formatter::Prettyplease)
  24         .header(
  25             top_dir
  26                 .join("src")
  27                 .join("libbcachefs_wrapper.h")
  28                 .display()
  29                 .to_string(),
  30         )
  31         .clang_args(
  32             urcu
  33                 .include_paths
  34                 .iter()
  35                 .map(|p| format!("-I{}", p.display())),
  36         )
  37         .clang_arg("-I..")
  38         .clang_arg("-I../c_src")
  39         .clang_arg("-I../include")
  40         .clang_arg("-DZSTD_STATIC_LINKING_ONLY")
  41         .clang_arg("-DNO_BCACHEFS_FS")
  42         .clang_arg("-D_GNU_SOURCE")
  43         .clang_arg("-DRUST_BINDGEN")
  44         .clang_arg("-fkeep-inline-functions")
  45         .derive_debug(true)
  46         .derive_default(true)
  47         .layout_tests(true)
  48         .default_enum_style(bindgen::EnumVariation::Rust {
  49             non_exhaustive: true,
  50         })
  51         .allowlist_function("bcachefs_usage")
  52         .allowlist_function("raid_init")
  53         .allowlist_function("cmd_.*")
  54         .allowlist_function(".*_cmds")
  55         .allowlist_function(".*bch2_.*")
  56         .allowlist_function("bio_.*")
  57         .allowlist_function("derive_passphrase")
  58         .allowlist_function("request_key")
  59         .allowlist_function("add_key")
  60         .allowlist_function("keyctl_search")
  61         .allowlist_function("match_string")
  62         .allowlist_function("printbuf.*")
  63         .blocklist_type("rhash_lock_head")
  64         .blocklist_type("srcu_struct")
  65         .allowlist_var("BCH_.*")
  66         .allowlist_var("KEY_SPEC_.*")
  67         .allowlist_var("Fix753_.*")
  68         .allowlist_var("bch.*")
  69         .allowlist_var("__bch2.*")
  70         .allowlist_var("__BTREE_ITER.*")
  71         .allowlist_var("BTREE_ITER.*")
  72         .blocklist_item("bch2_bkey_ops")
  73         .allowlist_type("bch_.*")
  74         .allowlist_type("fsck_err_opts")
  75         .rustified_enum("fsck_err_opts")
  76         .allowlist_type("nonce")
  77         .no_debug("bch_replicas_padded")
  78         .newtype_enum("bch_kdf_types")
  79         .rustified_enum("bch_key_types")
  80         .opaque_type("gendisk")
  81         .opaque_type("gc_stripe")
  82         .opaque_type("open_bucket.*")
  83         .opaque_type("replicas_delta_list")
  84         .no_copy("btree_trans")
  85         .no_copy("printbuf")
  86         .no_partialeq("bkey")
  87         .no_partialeq("bpos")
  88         .generate_inline_functions(true)
  89         .parse_callbacks(Box::new(Fix753 {}))
  90         .generate()
  91         .expect("BindGen Generation Failiure: [libbcachefs_wrapper]");
  92
  93     std::fs::write(
  94         out_dir.join("bcachefs.rs"),
  95         packed_and_align_fix(bindings.to_string()),
  96     )
  97     .expect("Writing to output file failed for: `bcachefs.rs`");
  98
  99     let keyutils = pkg_config::probe_library("libkeyutils").expect("Failed to find keyutils lib");
 100     let bindings = bindgen::builder()
 101         .header(
 102             top_dir
 103                 .join("src")
 104                 .join("keyutils_wrapper.h")
 105                 .display()
 106                 .to_string(),
 107         )
 108         .clang_args(
 109             keyutils
 110                 .include_paths
 111                 .iter()
 112                 .map(|p| format!("-I{}", p.display())),
 113         )
 114         .generate()
 115         .expect("BindGen Generation Failiure: [Keyutils]");
 116     bindings
 117         .write_to_file(out_dir.join("keyutils.rs"))
 118         .expect("Writing to output file failed for: `keyutils.rs`");
 119 }
 120
 121 // rustc has a limitation where it does not allow structs to have both a "packed" and "align"
 122 // attribute. This means that bindgen cannot copy all attributes from some C types, like struct
 123 // bkey, that are both packed and aligned.
 124 //
 125 // bindgen tries to handle this situation smartly and for many types it will only apply a
 126 // "packed(N)" attribute if that is good enough. However, there are a few types where bindgen
 127 // does end up generating both a packed(N) and align(N) attribute. These types can't be compiled
 128 // by rustc.
 129 //
 130 // To work around this, we can remove either the "packed" or "align" attribute. It happens that
 131 // for all the types with this problem in bcachefs, removing the "packed" attribute and keeping
 132 // the "align" attribute results in a type with the correct ABI.
 133 //
 134 // This function applies that transformation to the following bcachefs types that need it:
 135 //   - bkey
 136 //   - bch_extent_crc32
 137 //   - bch_extent_ptr
 138 //   - btree_node
 139 fn packed_and_align_fix(bindings: std::string::String) -> std::string::String {
 140     bindings
 141         .replace(
 142             "#[repr(C, packed(8))]\n#[repr(align(8))]\n#[derive(Debug, Default, Copy, Clone)]\npub struct bkey {",
 143             "#[repr(C, align(8))]\n#[derive(Debug, Default, Copy, Clone)]\npub struct bkey {",
 144         )
 145         .replace(
 146             "#[repr(C, packed(8))]\n#[repr(align(8))]\n#[derive(Debug, Default, Copy, Clone)]\npub struct bch_extent_crc32 {",
 147             "#[repr(C, align(8))]\n#[derive(Debug, Default, Copy, Clone)]\npub struct bch_extent_crc32 {",
 148         )
 149         .replace(
 150             "#[repr(C, packed(8))]\n#[repr(align(8))]\n#[derive(Debug, Default, Copy, Clone)]\npub struct bch_extent_ptr {",
 151             "#[repr(C, align(8))]\n#[derive(Debug, Default, Copy, Clone)]\npub struct bch_extent_ptr {",
 152         )
 153         .replace(
 154             "#[repr(C, packed(8))]\npub struct btree_node {",
 155             "#[repr(C, align(8))]\npub struct btree_node {",
 156         )
 157 }