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("bcache_fs_open")
  57         .allowlist_function("bcache_fs_close")
  58         .allowlist_function("bio_.*")
  59         .allowlist_function("derive_passphrase")
  60         .allowlist_function("request_key")
  61         .allowlist_function("add_key")
  62         .allowlist_function("keyctl_search")
  63         .allowlist_function("match_string")
  64         .allowlist_function("printbuf.*")
  65         .blocklist_type("rhash_lock_head")
  66         .blocklist_type("srcu_struct")
  67         .blocklist_type("bch_ioctl_data.*")
  68         .allowlist_var("BCH_.*")
  69         .allowlist_var("KEY_SPEC_.*")
  70         .allowlist_var("Fix753_.*")
  71         .allowlist_var("bch.*")
  72         .allowlist_var("__bch2.*")
  73         .allowlist_var("__BTREE_ITER.*")
  74         .allowlist_var("BTREE_ITER.*")
  75         .blocklist_item("bch2_bkey_ops")
  76         .allowlist_type("bch_.*")
  77         .allowlist_type("fsck_err_opts")
  78         .rustified_enum("fsck_err_opts")
  79         .allowlist_type("nonce")
  80         .no_debug("bch_replicas_padded")
  81         .newtype_enum("bch_kdf_types")
  82         .rustified_enum("bch_key_types")
  83         .opaque_type("gendisk")
  84         .opaque_type("gc_stripe")
  85         .opaque_type("open_bucket.*")
  86         .opaque_type("replicas_delta_list")
  87         .no_copy("btree_trans")
  88         .no_copy("printbuf")
  89         .no_partialeq("bkey")
  90         .no_partialeq("bpos")
  91         .generate_inline_functions(true)
  92         .parse_callbacks(Box::new(Fix753 {}))
  93         .generate()
  94         .expect("BindGen Generation Failiure: [libbcachefs_wrapper]");
  95
  96     std::fs::write(
  97         out_dir.join("bcachefs.rs"),
  98         packed_and_align_fix(bindings.to_string()),
  99     )
 100     .expect("Writing to output file failed for: `bcachefs.rs`");
 101
 102     let keyutils = pkg_config::probe_library("libkeyutils").expect("Failed to find keyutils lib");
 103     let bindings = bindgen::builder()
 104         .header(
 105             top_dir
 106                 .join("src")
 107                 .join("keyutils_wrapper.h")
 108                 .display()
 109                 .to_string(),
 110         )
 111         .clang_args(
 112             keyutils
 113                 .include_paths
 114                 .iter()
 115                 .map(|p| format!("-I{}", p.display())),
 116         )
 117         .generate()
 118         .expect("BindGen Generation Failiure: [Keyutils]");
 119     bindings
 120         .write_to_file(out_dir.join("keyutils.rs"))
 121         .expect("Writing to output file failed for: `keyutils.rs`");
 122 }
 123
 124 // rustc has a limitation where it does not allow structs with a "packed" attribute to contain a
 125 // member with an "align(N)" attribute. There are a few types in bcachefs with this problem. We can
 126 // "fix" these types by stripping off "packed" from the outer type, or "align(N)" from the inner
 127 // type. For all of the affected types, stripping "packed" from the outer type happens to preserve
 128 // the same layout in Rust as in C.
 129 //
 130 // Some types are only affected on attributes on architectures where the natural alignment of u64
 131 // is 4 instead of 8, for example i686 or ppc64: struct bch_csum and struct bch_sb_layout have
 132 // "align(8)" added on such architecutres. These types are included by several "packed" types:
 133 //   - bch_extent_crc128
 134 //   - jset
 135 //   - btree_node_entry
 136 //   - bch_sb
 137 //
 138 // TODO: find a way to conditionally include arch-specific modifications when compiling for that
 139 // target arch. Regular conditional compilation won't work here since build scripts are always
 140 // compiled for the host arch, not the target arch, so that won't work when cross-compiling.
 141 fn packed_and_align_fix(bindings: std::string::String) -> std::string::String {
 142     bindings
 143         .replace(
 144             "#[repr(C, packed(8))]\npub struct btree_node {",
 145             "#[repr(C, align(8))]\npub struct btree_node {",
 146         )
 147         .replace(
 148             "#[repr(C, packed(8))]\n#[derive(Debug, Default, Copy, Clone)]\npub struct bch_extent_crc128 {",
 149             "#[repr(C, align(8))]\n#[derive(Debug, Default, Copy, Clone)]\npub struct bch_extent_crc128 {",
 150         )
 151         .replace(
 152             "#[repr(C, packed(8))]\npub struct jset {",
 153             "#[repr(C, align(8))]\npub struct jset {",
 154         )
 155         .replace(
 156             "#[repr(C, packed(8))]\npub struct btree_node_entry {",
 157             "#[repr(C, align(8))]\npub struct btree_node_entry {",
 158         )
 159         .replace(
 160             "#[repr(C, packed(8))]\npub struct bch_sb {",
 161             "#[repr(C, align(8))]\npub struct bch_sb {",
 162         )
 163 }