Initiate the inner usage of cfg_match (Library)

Author: c410-f3r

Cargo.lock

@@ -2676,7 +2676,6 @@ name = "panic_abort"
 version = "0.0.0"
 dependencies = [
  "alloc",
- "cfg-if",
  "compiler_builtins",
  "core",
  "libc",
@@ -5836,7 +5835,6 @@ name = "unwind"
 version = "0.0.0"
 dependencies = [
  "cc",
- "cfg-if",
  "compiler_builtins",
  "core",
  "libc",

library/core/src/ffi/mod.rs

@@ -97,9 +97,9 @@ pub type c_ptrdiff_t = isize;
 pub type c_ssize_t = isize;
 
 mod c_char_definition {
-    cfg_if! {
+    cfg_match! {
         // These are the targets on which c_char is unsigned.
-        if #[cfg(any(
+        cfg(any(
             all(
                 target_os = "linux",
                 any(
@@ -150,10 +150,11 @@ mod c_char_definition {
             ),
             all(target_os = "nto", target_arch = "aarch64"),
             target_os = "horizon"
-        ))] {
+        )) => {
             pub type c_char = u8;
             pub type NonZero_c_char = crate::num::NonZeroU8;
-        } else {
+        }
+        _ => {
             // On every other target, c_char is signed.
             pub type c_char = i8;
             pub type NonZero_c_char = crate::num::NonZeroI8;
@@ -162,13 +163,14 @@ mod c_char_definition {
 }
 
 mod c_int_definition {
-    cfg_if! {
-        if #[cfg(any(target_arch = "avr", target_arch = "msp430"))] {
+    cfg_match! {
+        cfg(any(target_arch = "avr", target_arch = "msp430")) => {
             pub type c_int = i16;
             pub type NonZero_c_int = crate::num::NonZeroI16;
             pub type c_uint = u16;
             pub type NonZero_c_uint = crate::num::NonZeroU16;
-        } else {
+        }
+        _ => {
             pub type c_int = i32;
             pub type NonZero_c_int = crate::num::NonZeroI32;
             pub type c_uint = u32;
@@ -178,13 +180,14 @@ mod c_int_definition {
 }
 
 mod c_long_definition {
-    cfg_if! {
-        if #[cfg(all(target_pointer_width = "64", not(windows)))] {
+    cfg_match! {
+        cfg(all(target_pointer_width = "64", not(windows))) => {
             pub type c_long = i64;
             pub type NonZero_c_long = crate::num::NonZeroI64;
             pub type c_ulong = u64;
             pub type NonZero_c_ulong = crate::num::NonZeroU64;
-        } else {
+        }
+        _ =>{
             // The minimal size of `long` in the C standard is 32 bits
             pub type c_long = i32;
             pub type NonZero_c_long = crate::num::NonZeroI32;

library/core/src/internal_macros.rs

@@ -117,79 +117,3 @@ macro_rules! impl_fn_for_zst {
     }
 }
 
-/// A macro for defining `#[cfg]` if-else statements.
-///
-/// `cfg_if` is similar to the `if/elif` C preprocessor macro by allowing definition of a cascade
-/// of `#[cfg]` cases, emitting the implementation which matches first.
-///
-/// This allows you to conveniently provide a long list `#[cfg]`'d blocks of code without having to
-/// rewrite each clause multiple times.
-///
-/// # Example
-///
-/// ```ignore(cannot-test-this-because-non-exported-macro)
-/// cfg_if! {
-///     if #[cfg(unix)] {
-///         fn foo() { /* unix specific functionality */ }
-///     } else if #[cfg(target_pointer_width = "32")] {
-///         fn foo() { /* non-unix, 32-bit functionality */ }
-///     } else {
-///         fn foo() { /* fallback implementation */ }
-///     }
-/// }
-///
-/// # fn main() {}
-/// ```
-// This is a copy of `cfg_if!` from the `cfg_if` crate.
-// The recursive invocations should use $crate if this is ever exported.
-macro_rules! cfg_if {
-    // match if/else chains with a final `else`
-    (
-        $(
-            if #[cfg( $i_meta:meta )] { $( $i_tokens:tt )* }
-        ) else+
-        else { $( $e_tokens:tt )* }
-    ) => {
-        cfg_if! {
-            @__items () ;
-            $(
-                (( $i_meta ) ( $( $i_tokens )* )) ,
-            )+
-            (() ( $( $e_tokens )* )) ,
-        }
-    };
-
-    // Internal and recursive macro to emit all the items
-    //
-    // Collects all the previous cfgs in a list at the beginning, so they can be
-    // negated. After the semicolon is all the remaining items.
-    (@__items ( $( $_:meta , )* ) ; ) => {};
-    (
-        @__items ( $( $no:meta , )* ) ;
-        (( $( $yes:meta )? ) ( $( $tokens:tt )* )) ,
-        $( $rest:tt , )*
-    ) => {
-        // Emit all items within one block, applying an appropriate #[cfg]. The
-        // #[cfg] will require all `$yes` matchers specified and must also negate
-        // all previous matchers.
-        #[cfg(all(
-            $( $yes , )?
-            not(any( $( $no ),* ))
-        ))]
-        cfg_if! { @__identity $( $tokens )* }
-
-        // Recurse to emit all other items in `$rest`, and when we do so add all
-        // our `$yes` matchers to the list of `$no` matchers as future emissions
-        // will have to negate everything we just matched as well.
-        cfg_if! {
-            @__items ( $( $no , )* $( $yes , )? ) ;
-            $( $rest , )*
-        }
-    };
-
-    // Internal macro to make __apply work out right for different match types,
-    // because of how macros match/expand stuff.
-    (@__identity $( $tokens:tt )* ) => {
-        $( $tokens )*
-    };
-}

library/core/src/lib.rs

@@ -112,6 +112,7 @@
 // tidy-alphabetical-start
 #![cfg_attr(bootstrap, feature(no_coverage))] // rust-lang/rust#84605
 #![cfg_attr(not(bootstrap), feature(coverage_attribute))] // rust-lang/rust#84605
+#![feature(cfg_match)]
 #![feature(char_indices_offset)]
 #![feature(const_align_of_val)]
 #![feature(const_align_of_val_raw)]

library/panic_abort/Cargo.toml

@@ -13,7 +13,6 @@ doc = false
 
 [dependencies]
 alloc = { path = "../alloc" }
-cfg-if = { version = "1.0", features = ['rustc-dep-of-std'] }
 core = { path = "../core" }
 libc = { version = "0.2", default-features = false }
 compiler_builtins = "0.1.0"

library/panic_abort/src/lib.rs

@@ -8,6 +8,7 @@
 #![doc(issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/")]
 #![panic_runtime]
 #![allow(unused_features)]
+#![feature(cfg_match)]
 #![feature(core_intrinsics)]
 #![feature(panic_runtime)]
 #![feature(std_internals)]
@@ -37,24 +38,26 @@ pub unsafe fn __rust_start_panic(_payload: &mut dyn PanicPayload) -> u32 {
 
     abort();
 
-    cfg_if::cfg_if! {
-        if #[cfg(any(unix, target_os = "solid_asp3"))] {
+    cfg_match! {
+        cfg(any(unix, target_os = "solid_asp3")) => {
             unsafe fn abort() -> ! {
                 libc::abort();
             }
-        } else if #[cfg(any(target_os = "hermit",
-                            all(target_vendor = "fortanix", target_env = "sgx"),
-                            target_os = "xous",
-                            target_os = "uefi",
-        ))] {
+        }
+        cfg(any(target_os = "hermit",
+            all(target_vendor = "fortanix", target_env = "sgx"),
+            target_os = "xous",
+            target_os = "uefi",
+        )) => {
             unsafe fn abort() -> ! {
                 // call std::sys::abort_internal
                 extern "C" {
                     pub fn __rust_abort() -> !;
                 }
                 __rust_abort();
             }
-        } else if #[cfg(all(windows, not(miri)))] {
+        }
+        cfg(all(windows, not(miri))) => {
             // On Windows, use the processor-specific __fastfail mechanism. In Windows 8
             // and later, this will terminate the process immediately without running any
             // in-process exception handlers. In earlier versions of Windows, this
@@ -68,20 +71,24 @@ pub unsafe fn __rust_start_panic(_payload: &mut dyn PanicPayload) -> u32 {
             unsafe fn abort() -> ! {
                 #[allow(unused)]
                 const FAST_FAIL_FATAL_APP_EXIT: usize = 7;
-                cfg_if::cfg_if! {
-                    if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
+                cfg_match! {
+                    cfg(any(target_arch = "x86", target_arch = "x86_64")) => {
                         core::arch::asm!("int $$0x29", in("ecx") FAST_FAIL_FATAL_APP_EXIT);
-                    } else if #[cfg(all(target_arch = "arm", target_feature = "thumb-mode"))] {
+                    }
+                    cfg(all(target_arch = "arm", target_feature = "thumb-mode")) => {
                         core::arch::asm!(".inst 0xDEFB", in("r0") FAST_FAIL_FATAL_APP_EXIT);
-                    } else if #[cfg(target_arch = "aarch64")] {
+                    }
+                    cfg(target_arch = "aarch64") => {
                         core::arch::asm!("brk 0xF003", in("x0") FAST_FAIL_FATAL_APP_EXIT);
-                    } else {
+                    }
+                    _ => {
                         core::intrinsics::abort();
                     }
                 }
                 core::intrinsics::unreachable();
             }
-        } else {
+        }
+        _ => {
             unsafe fn abort() -> ! {
                 core::intrinsics::abort();
             }

library/panic_unwind/src/lib.rs

@@ -14,6 +14,7 @@
 #![no_std]
 #![unstable(feature = "panic_unwind", issue = "32837")]
 #![doc(issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/")]
+#![feature(cfg_match)]
 #![feature(core_intrinsics)]
 #![feature(lang_items)]
 #![feature(panic_unwind)]
@@ -31,31 +32,36 @@ use alloc::boxed::Box;
 use core::any::Any;
 use core::panic::PanicPayload;
 
-cfg_if::cfg_if! {
-    if #[cfg(target_os = "emscripten")] {
+cfg_match! {
+    cfg(target_os = "emscripten") => {
         #[path = "emcc.rs"]
         mod real_imp;
-    } else if #[cfg(target_os = "hermit")] {
+    } 
+    cfg(target_os = "hermit") => {
         #[path = "hermit.rs"]
         mod real_imp;
-    } else if #[cfg(target_os = "l4re")] {
+    } 
+    cfg(target_os = "l4re") => {
         // L4Re is unix family but does not yet support unwinding.
         #[path = "dummy.rs"]
         mod real_imp;
-    } else if #[cfg(all(target_env = "msvc", not(target_arch = "arm")))] {
+    } 
+    cfg(all(target_env = "msvc", not(target_arch = "arm"))) => {
         // LLVM does not support unwinding on 32 bit ARM msvc (thumbv7a-pc-windows-msvc)
         #[path = "seh.rs"]
         mod real_imp;
-    } else if #[cfg(any(
+    }
+    cfg(any(
         all(target_family = "windows", target_env = "gnu"),
         target_os = "psp",
         target_os = "solid_asp3",
         all(target_family = "unix", not(target_os = "espidf")),
         all(target_vendor = "fortanix", target_env = "sgx"),
-    ))] {
+    )) => {
         #[path = "gcc.rs"]
         mod real_imp;
-    } else {
+    }
+    _ => {
         // Targets that don't support unwinding.
         // - family=wasm
         // - os=none ("bare metal" targets)
@@ -68,14 +74,15 @@ cfg_if::cfg_if! {
     }
 }
 
-cfg_if::cfg_if! {
-    if #[cfg(miri)] {
+cfg_match! {
+    cfg(miri) => {
         // Use the Miri runtime.
         // We still need to also load the normal runtime above, as rustc expects certain lang
         // items from there to be defined.
         #[path = "miri.rs"]
         mod imp;
-    } else {
+    }
+    _ => {
         // Use the real runtime.
         use real_imp as imp;
     }

library/panic_unwind/src/seh.rs

@@ -253,10 +253,11 @@ macro_rules! define_cleanup {
         }
     }
 }
-cfg_if::cfg_if! {
-   if #[cfg(target_arch = "x86")] {
+cfg_match! {
+   cfg(target_arch = "x86") => {
        define_cleanup!("thiscall" "thiscall-unwind");
-   } else {
+   }
+   _ => {
        define_cleanup!("C" "C-unwind");
    }
 }

library/std/src/lib.rs

@@ -305,6 +305,7 @@
 //
 // Library features (core):
 // tidy-alphabetical-start
+#![feature(cfg_match)]
 #![feature(char_internals)]
 #![feature(core_intrinsics)]
 #![feature(duration_constants)]

library/std/src/os/unix/process.rs

@@ -12,19 +12,19 @@ use crate::sealed::Sealed;
 use crate::sys;
 use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 
-use cfg_if::cfg_if;
-
-cfg_if! {
-    if #[cfg(any(target_os = "vxworks", target_os = "espidf", target_os = "horizon", target_os = "vita"))] {
+cfg_match! {
+    cfg(any(target_os = "vxworks", target_os = "espidf", target_os = "horizon", target_os = "vita")) => {
         type UserId = u16;
         type GroupId = u16;
-    } else if #[cfg(target_os = "nto")] {
+    } 
+    cfg(target_os = "nto") => {
         // Both IDs are signed, see `sys/target_nto.h` of the QNX Neutrino SDP.
         // Only positive values should be used, see e.g.
         // https://www.qnx.com/developers/docs/7.1/#com.qnx.doc.neutrino.lib_ref/topic/s/setuid.html
         type UserId = i32;
         type GroupId = i32;
-    } else {
+    }
+    _ => {
         type UserId = u32;
         type GroupId = u32;
     }