Remove cfg hacks for old MSRV

Author: JohnTitor

Cargo.toml

@@ -14,6 +14,7 @@ exclude = ["/ci/*", "/.github/*", "/.cirrus.yml", "/triagebot.toml"]
 description = """
 Raw FFI bindings to platform libraries like libc.
 """
+rust-version = "1.71.0"
 
 [package.metadata.docs.rs]
 features = ["const-extern-fn", "extra_traits"]

README.md

@@ -51,21 +51,9 @@ libc = "0.2"
 
 ## Rust version support
 
-The minimum supported Rust toolchain version is currently **Rust 1.13.0**.
+The minimum supported Rust toolchain version is currently **Rust 1.71.0**
 (libc does not currently have any policy regarding changes to the minimum
-supported Rust version; such policy is a work in progress.) APIs requiring
-newer Rust features are only available on newer Rust toolchains:
-
-| Feature              | Version |
-|----------------------|---------|
-| `union`              |  1.19.0 |
-| `const mem::size_of` |  1.24.0 |
-| `repr(align)`        |  1.25.0 |
-| `extra_traits`       |  1.25.0 |
-| `core::ffi::c_void`  |  1.30.0 |
-| `repr(packed(N))`    |  1.33.0 |
-| `cfg(target_vendor)` |  1.33.0 |
-| `const-extern-fn`    |  1.62.0 |
+supported Rust version; such policy is a work in progress).
 
 ## Platform support
 

build.rs

@@ -14,22 +14,8 @@ const ALLOWED_CFGS: &'static [&'static str] = &[
     "freebsd13",
     "freebsd14",
     "freebsd15",
-    "libc_align",
-    "libc_cfg_target_vendor",
-    "libc_const_extern_fn",
-    "libc_const_extern_fn_unstable",
-    "libc_const_size_of",
-    "libc_core_cvoid",
     "libc_deny_warnings",
-    "libc_int128",
-    "libc_long_array",
-    "libc_non_exhaustive",
-    "libc_packedN",
-    "libc_priv_mod_use",
-    "libc_ptr_addr_of",
     "libc_thread_local",
-    "libc_underscore_const_names",
-    "libc_union",
 ];
 
 // Extra values to allow for check-cfg.
@@ -46,10 +32,8 @@ fn main() {
     // Avoid unnecessary re-building.
     println!("cargo:rerun-if-changed=build.rs");
 
-    let (rustc_minor_ver, is_nightly) = rustc_minor_nightly();
+    let (rustc_minor_ver, _) = rustc_minor_nightly();
     let rustc_dep_of_std = env::var("CARGO_FEATURE_RUSTC_DEP_OF_STD").is_ok();
-    let align_cargo_feature = env::var("CARGO_FEATURE_ALIGN").is_ok();
-    let const_extern_fn_cargo_feature = env::var("CARGO_FEATURE_CONST_EXTERN_FN").is_ok();
     let libc_ci = env::var("LIBC_CI").is_ok();
     let libc_check_cfg = env::var("LIBC_CHECK_CFG").is_ok();
 
@@ -86,82 +70,11 @@ fn main() {
         set_cfg("libc_deny_warnings");
     }
 
-    // Rust >= 1.15 supports private module use:
-    if rustc_minor_ver >= 15 || rustc_dep_of_std {
-        set_cfg("libc_priv_mod_use");
-    }
-
-    // Rust >= 1.19 supports unions:
-    if rustc_minor_ver >= 19 || rustc_dep_of_std {
-        set_cfg("libc_union");
-    }
-
-    // Rust >= 1.24 supports const mem::size_of:
-    if rustc_minor_ver >= 24 || rustc_dep_of_std {
-        set_cfg("libc_const_size_of");
-    }
-
-    // Rust >= 1.25 supports repr(align):
-    if rustc_minor_ver >= 25 || rustc_dep_of_std || align_cargo_feature {
-        set_cfg("libc_align");
-    }
-
-    // Rust >= 1.26 supports i128 and u128:
-    if rustc_minor_ver >= 26 || rustc_dep_of_std {
-        set_cfg("libc_int128");
-    }
-
-    // Rust >= 1.30 supports `core::ffi::c_void`, so libc can just re-export it.
-    // Otherwise, it defines an incompatible type to retaining
-    // backwards-compatibility.
-    if rustc_minor_ver >= 30 || rustc_dep_of_std {
-        set_cfg("libc_core_cvoid");
-    }
-
-    // Rust >= 1.33 supports repr(packed(N)) and cfg(target_vendor).
-    if rustc_minor_ver >= 33 || rustc_dep_of_std {
-        set_cfg("libc_packedN");
-        set_cfg("libc_cfg_target_vendor");
-    }
-
-    // Rust >= 1.40 supports #[non_exhaustive].
-    if rustc_minor_ver >= 40 || rustc_dep_of_std {
-        set_cfg("libc_non_exhaustive");
-    }
-
-    // Rust >= 1.47 supports long array:
-    if rustc_minor_ver >= 47 || rustc_dep_of_std {
-        set_cfg("libc_long_array");
-    }
-
-    if rustc_minor_ver >= 51 || rustc_dep_of_std {
-        set_cfg("libc_ptr_addr_of");
-    }
-
-    // Rust >= 1.37.0 allows underscores as anonymous constant names.
-    if rustc_minor_ver >= 37 || rustc_dep_of_std {
-        set_cfg("libc_underscore_const_names");
-    }
-
     // #[thread_local] is currently unstable
     if rustc_dep_of_std {
         set_cfg("libc_thread_local");
     }
 
-    // Rust >= 1.62.0 allows to use `const_extern_fn` for "Rust" and "C".
-    if rustc_minor_ver >= 62 {
-        set_cfg("libc_const_extern_fn");
-    } else {
-        // Rust < 1.62.0 requires a crate feature and feature gate.
-        if const_extern_fn_cargo_feature {
-            if !is_nightly || rustc_minor_ver < 40 {
-                panic!("const-extern-fn requires a nightly compiler >= 1.40");
-            }
-            set_cfg("libc_const_extern_fn_unstable");
-            set_cfg("libc_const_extern_fn");
-        }
-    }
-
     // check-cfg is a nightly cargo/rustc feature to warn when unknown cfgs are used across the
     // codebase. libc can configure it if the appropriate environment variable is passed. Since
     // rust-lang/rust enforces it, this is useful when using a custom libc fork there.

libc-test/build.rs

@@ -68,15 +68,7 @@ fn do_ctest() {
 
 fn ctest_cfg() -> ctest::TestGenerator {
     let mut cfg = ctest::TestGenerator::new();
-    let libc_cfgs = [
-        "libc_priv_mod_use",
-        "libc_union",
-        "libc_const_size_of",
-        "libc_align",
-        "libc_core_cvoid",
-        "libc_packedN",
-        "libc_thread_local",
-    ];
+    let libc_cfgs = ["libc_thread_local"];
     for f in &libc_cfgs {
         cfg.cfg(f, None);
     }

src/fixed_width_ints.rs

@@ -20,7 +20,7 @@ pub type uint32_t = u32;
 pub type uint64_t = u64;
 
 cfg_if! {
-    if #[cfg(all(libc_int128, target_arch = "aarch64", not(target_os = "windows")))] {
+    if #[cfg(all(target_arch = "aarch64", not(target_os = "windows")))] {
         // This introduces partial support for FFI with __int128 and
         // equivalent types on platforms where Rust's definition is validated
         // to match the standard C ABI of that platform.
@@ -59,41 +59,37 @@ cfg_if! {
         /// C __uint128_t (alternate name for [__uint128][])
         pub type __uint128_t = u128;
 
-        cfg_if! {
-            if #[cfg(libc_underscore_const_names)] {
-                macro_rules! static_assert_eq {
-                    ($a:expr, $b:expr) => {
-                        const _: [(); $a] = [(); $b];
-                    };
-                }
+        macro_rules! static_assert_eq {
+            ($a:expr, $b:expr) => {
+                const _: [(); $a] = [(); $b];
+            };
+        }
 
-                // NOTE: if you add more platforms to here, you may need to cfg
-                // these consts. They should always match the platform's values
-                // for `sizeof(__int128)` and `_Alignof(__int128)`.
-                const _SIZE_128: usize = 16;
-                const _ALIGN_128: usize = 16;
+        // NOTE: if you add more platforms to here, you may need to cfg
+        // these consts. They should always match the platform's values
+        // for `sizeof(__int128)` and `_Alignof(__int128)`.
+        const _SIZE_128: usize = 16;
+        const _ALIGN_128: usize = 16;
 
-                // Since Rust doesn't officially guarantee that these types
-                // have compatible ABIs, we const assert that these values have the
-                // known size/align of the target platform's libc. If rustc ever
-                // tries to regress things, it will cause a compilation error.
-                //
-                // This isn't a bullet-proof solution because e.g. it doesn't
-                // catch the fact that llvm and gcc disagree on how x64 __int128
-                // is actually *passed* on the stack (clang underaligns it for
-                // the same reason that rustc *never* properly aligns it).
-                static_assert_eq!(core::mem::size_of::<__int128>(), _SIZE_128);
-                static_assert_eq!(core::mem::align_of::<__int128>(), _ALIGN_128);
+        // Since Rust doesn't officially guarantee that these types
+        // have compatible ABIs, we const assert that these values have the
+        // known size/align of the target platform's libc. If rustc ever
+        // tries to regress things, it will cause a compilation error.
+        //
+        // This isn't a bullet-proof solution because e.g. it doesn't
+        // catch the fact that llvm and gcc disagree on how x64 __int128
+        // is actually *passed* on the stack (clang underaligns it for
+        // the same reason that rustc *never* properly aligns it).
+        static_assert_eq!(core::mem::size_of::<__int128>(), _SIZE_128);
+        static_assert_eq!(core::mem::align_of::<__int128>(), _ALIGN_128);
 
-                static_assert_eq!(core::mem::size_of::<__uint128>(), _SIZE_128);
-                static_assert_eq!(core::mem::align_of::<__uint128>(), _ALIGN_128);
+        static_assert_eq!(core::mem::size_of::<__uint128>(), _SIZE_128);
+        static_assert_eq!(core::mem::align_of::<__uint128>(), _ALIGN_128);
 
-                static_assert_eq!(core::mem::size_of::<__int128_t>(), _SIZE_128);
-                static_assert_eq!(core::mem::align_of::<__int128_t>(), _ALIGN_128);
+        static_assert_eq!(core::mem::size_of::<__int128_t>(), _SIZE_128);
+        static_assert_eq!(core::mem::align_of::<__int128_t>(), _ALIGN_128);
 
-                static_assert_eq!(core::mem::size_of::<__uint128_t>(), _SIZE_128);
-                static_assert_eq!(core::mem::align_of::<__uint128_t>(), _ALIGN_128);
-            }
-        }
+        static_assert_eq!(core::mem::size_of::<__uint128_t>(), _SIZE_128);
+        static_assert_eq!(core::mem::align_of::<__uint128_t>(), _ALIGN_128);
     }
 }

src/fuchsia/mod.rs

@@ -2315,17 +2315,15 @@ pub const RTLD_NOW: ::c_int = 0x2;
 
 pub const TCP_MD5SIG: ::c_int = 14;
 
-align_const! {
-    pub const PTHREAD_MUTEX_INITIALIZER: pthread_mutex_t = pthread_mutex_t {
-        size: [0; __SIZEOF_PTHREAD_MUTEX_T],
-    };
-    pub const PTHREAD_COND_INITIALIZER: pthread_cond_t = pthread_cond_t {
-        size: [0; __SIZEOF_PTHREAD_COND_T],
-    };
-    pub const PTHREAD_RWLOCK_INITIALIZER: pthread_rwlock_t = pthread_rwlock_t {
-        size: [0; __SIZEOF_PTHREAD_RWLOCK_T],
-    };
-}
+pub const PTHREAD_MUTEX_INITIALIZER: pthread_mutex_t = pthread_mutex_t {
+    size: [0; __SIZEOF_PTHREAD_MUTEX_T],
+};
+pub const PTHREAD_COND_INITIALIZER: pthread_cond_t = pthread_cond_t {
+    size: [0; __SIZEOF_PTHREAD_COND_T],
+};
+pub const PTHREAD_RWLOCK_INITIALIZER: pthread_rwlock_t = pthread_rwlock_t {
+    size: [0; __SIZEOF_PTHREAD_RWLOCK_T],
+};
 pub const PTHREAD_MUTEX_NORMAL: ::c_int = 0;
 pub const PTHREAD_MUTEX_RECURSIVE: ::c_int = 1;
 pub const PTHREAD_MUTEX_ERRORCHECK: ::c_int = 2;
@@ -4361,33 +4359,9 @@ cfg_if! {
     }
 }
 
-cfg_if! {
-    if #[cfg(libc_align)] {
-        #[macro_use]
-        mod align;
-    } else {
-        #[macro_use]
-        mod no_align;
-    }
-}
+#[macro_use]
+mod align;
+
 expand_align!();
 
-cfg_if! {
-    if #[cfg(libc_core_cvoid)] {
-        pub use ::ffi::c_void;
-    } else {
-        // Use repr(u8) as LLVM expects `void*` to be the same as `i8*` to help
-        // enable more optimization opportunities around it recognizing things
-        // like malloc/free.
-        #[repr(u8)]
-        #[allow(missing_copy_implementations)]
-        #[allow(missing_debug_implementations)]
-        pub enum c_void {
-            // Two dummy variants so the #[repr] attribute can be used.
-            #[doc(hidden)]
-            __variant1,
-            #[doc(hidden)]
-            __variant2,
-        }
-    }
-}
+pub use ffi::c_void;