statics !!!!!! expect it doesn't work :-(

error[E0493]: destructor of `TargetOptions` cannot be evaluated at compile-time
  --> compiler/rustc_target/src/spec/targets/nvptx64_nvidia_cuda.rs:50:15
   |
50 |             ..TargetOptions::default()
   |               ^^^^^^^^^^^^^^^^^^^^^^^^ the destructor for this type cannot be evaluated in statics
...
53 | };
   | - value is dropped here

error[E0015]: cannot call non-const operator in statics
    --> compiler/rustc_target/src/spec/targets/x86_64_unknown_none.rs:26:31
     |
26   |         supported_sanitizers: SanitizerSet::KCFI | SanitizerSet::KERNELADDRESS,
     |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
note: impl defined here, but it is not `const`
    --> /home/archie/.cargo/registry/src/index.crates.io-6f17d22bba15001f/bitflags-2.4.2/src/public.rs:359:9
     |
317  |   macro_rules! __impl_public_bitflags_ops {
     |   --------------------------------------- in this expansion of `$crate::__impl_public_bitflags_ops!` (#2)
...
359  |           impl $crate::__private::core::ops::BitOr for $PublicBitFlags {
     |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
    ::: /home/archie/.cargo/registry/src/index.crates.io-6f17d22bba15001f/bitflags-2.4.2/src/lib.rs:446:1
     |
446  |   macro_rules! bitflags {
     |   --------------------- in this expansion of `bitflags::bitflags!` (#1)
...
571  | /             $crate::__impl_public_bitflags_ops! {
572  | |                 $BitFlags
573  | |             }
     | |_____________- in this macro invocation (#2)
     |
    ::: compiler/rustc_target/src/spec/mod.rs:1220:1
     |
1220 | / bitflags::bitflags! {
1221 | |     impl SanitizerSet: u16 {
1222 | |         const ADDRESS = 1 << 0;
1223 | |         const LEAK    = 1 << 1;
...    |
1234 | |     }
1235 | | }
     | |_- in this macro invocation (#1)
     = note: calls in statics are limited to constant functions, tuple structs and tuple variants
     = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
     = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell

Author: Urgau

compiler/rustc_target/src/spec/mod.rs

@@ -1382,18 +1382,18 @@ macro_rules! supported_targets {
         /// List of supported targets
         pub const TARGETS: &[&str] = &[$($triple),+];
 
-        fn load_builtin(target: &str) -> Option<Target> {
+        fn load_builtin(target: &str) -> Option<&'static Target> {
             let mut t = match target {
-                $( $triple => targets::$module::target(), )+
+                $( $triple => &targets::$module::TARGET, )+
                 _ => return None,
             };
-            t.is_builtin = true;
+            // TODO: t.is_builtin = true;
             debug!("got builtin target: {:?}", t);
             Some(t)
         }
 
-        fn load_all_builtin() -> impl Iterator<Item = Target> {
-            [$(targets::$module::target, )*].iter().map(|f| f())
+        fn load_all_builtins() -> impl Iterator<Item = &'static Target> {
+            [$(&targets::$module::TARGET, )*].into_iter()
         }
 
         #[cfg(test)]
@@ -3141,7 +3141,7 @@ impl Target {
     }
 
     /// Load a built-in target
-    pub fn expect_builtin(target_triple: &TargetTriple) -> Target {
+    pub fn expect_builtin(target_triple: &TargetTriple) -> &'static Target {
         match *target_triple {
             TargetTriple::TargetTriple(ref target_triple) => {
                 load_builtin(target_triple).expect("built-in target")
@@ -3153,8 +3153,8 @@ impl Target {
     }
 
     /// Load all built-in targets
-    pub fn iter_builtins() -> impl Iterator<Item = Target> {
-        load_all_builtin()
+    pub fn iter_builtins() -> impl Iterator<Item = &'static Target> {
+        load_all_builtins()
     }
 
     /// Search for a JSON file specifying the given target triple.
@@ -3182,9 +3182,11 @@ impl Target {
         match *target_triple {
             TargetTriple::TargetTriple(ref target_triple) => {
                 // check if triple is in list of built-in targets
-                if let Some(t) = load_builtin(target_triple) {
-                    return Ok((t, TargetWarnings::empty()));
-                }
+                // TODO: Make a custom type that either statically borrow a Target
+                // or has a owned Target (a bit like Cow but without the write part)
+                // if let Some(t) = load_builtin(target_triple) {
+                //     return Ok((t, TargetWarnings::empty()));
+                // }
 
                 // search for a file named `target_triple`.json in RUST_TARGET_PATH
                 let path = {

compiler/rustc_target/src/spec/targets/aarch64_apple_darwin.rs

@@ -4,7 +4,7 @@ use std::sync::LazyLock;
 use crate::spec::base::apple::{macos_llvm_target, opts, pre_link_args, Arch};
 use crate::spec::{FramePointer, SanitizerSet, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     const ARCH: Arch = Arch::Arm64;
     const OS: &'static str = "macos";
 
@@ -31,4 +31,4 @@ pub fn target() -> Target {
             ..base
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_apple_ios.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{FramePointer, SanitizerSet, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let arch = Arch::Arm64;
     let mut base = opts("ios", arch);
     base.supported_sanitizers = SanitizerSet::ADDRESS | SanitizerSet::THREAD;
@@ -24,4 +24,4 @@ pub fn target() -> Target {
             ..base
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_apple_ios_macabi.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{FramePointer, SanitizerSet, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let arch = Arch::Arm64_macabi;
     let mut base = opts("ios", arch);
     base.supported_sanitizers = SanitizerSet::ADDRESS | SanitizerSet::LEAK | SanitizerSet::THREAD;
@@ -20,4 +20,4 @@ pub fn target() -> Target {
             ..base
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_apple_ios_sim.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{FramePointer, SanitizerSet, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let arch = Arch::Arm64_sim;
     let mut base = opts("ios", arch);
     base.supported_sanitizers = SanitizerSet::ADDRESS | SanitizerSet::THREAD;
@@ -24,4 +24,4 @@ pub fn target() -> Target {
             ..base
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_apple_tvos.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{FramePointer, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let arch = Arch::Arm64;
     Target {
         llvm_target: tvos_llvm_target(arch).into(),
@@ -17,4 +17,4 @@ pub fn target() -> Target {
             ..opts("tvos", arch)
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_apple_tvos_sim.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{FramePointer, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let arch = Arch::Arm64_sim;
     Target {
         llvm_target: tvos_sim_llvm_target(arch).into(),
@@ -17,4 +17,4 @@ pub fn target() -> Target {
             ..opts("tvos", arch)
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_apple_watchos.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let base = opts("watchos", Arch::Arm64);
     Target {
         llvm_target: cow!("aarch64-apple-watchos"),
@@ -18,4 +18,4 @@ pub fn target() -> Target {
             ..base
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_apple_watchos_sim.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{FramePointer, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let arch = Arch::Arm64_sim;
     Target {
         // Clang automatically chooses a more specific target based on
@@ -21,4 +21,4 @@ pub fn target() -> Target {
             ..opts("watchos", arch)
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{base, StackProbeType, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     Target {
         llvm_target: cow!("aarch64_be-unknown-linux-gnu"),
         pointer_width: 64,
@@ -18,4 +18,4 @@ pub fn target() -> Target {
             ..base::linux_gnu::opts()
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu_ilp32.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{base, StackProbeType, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let mut base = base::linux_gnu::opts();
     base.max_atomic_width = Some(128);
 
@@ -21,4 +21,4 @@ pub fn target() -> Target {
             ..base
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_be_unknown_netbsd.rs

@@ -3,7 +3,7 @@ use crate::spec::cow;
 
 use crate::spec::{base, StackProbeType, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     Target {
         llvm_target: cow!("aarch64_be-unknown-netbsd"),
         pointer_width: 64,
@@ -17,4 +17,4 @@ pub fn target() -> Target {
             ..base::netbsd::opts()
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_fuchsia.rs

@@ -1 +1 @@
-pub use crate::spec::targets::aarch64_unknown_fuchsia::target;
+pub use crate::spec::targets::aarch64_unknown_fuchsia::TARGET;

compiler/rustc_target/src/spec/targets/aarch64_kmc_solid_asp3.rs

@@ -1,7 +1,7 @@
 use crate::spec::cow;
 use crate::spec::{base, RelocModel, StackProbeType, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let base = base::solid::opts("asp3");
     Target {
         llvm_target: cow!("aarch64-unknown-none"),
@@ -18,4 +18,4 @@ pub fn target() -> Target {
             ..base
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_linux_android.rs

@@ -4,7 +4,7 @@ use crate::spec::{base, SanitizerSet, StackProbeType, Target, TargetOptions};
 // See https://developer.android.com/ndk/guides/abis.html#arm64-v8a
 // for target ABI requirements.
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     Target {
         llvm_target: cow!("aarch64-linux-android"),
         pointer_width: 64,
@@ -25,4 +25,4 @@ pub fn target() -> Target {
             ..base::android::opts()
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_nintendo_switch_freestanding.rs

@@ -6,7 +6,7 @@ use crate::spec::{
 const LINKER_SCRIPT: &str = include_str!("./aarch64_nintendo_switch_freestanding_linker_script.ld");
 
 /// A base target for Nintendo Switch devices using a pure LLVM toolchain.
-pub fn target() -> Target {
+pub static TARGET: Target = {
     Target {
         llvm_target: cow!("aarch64-unknown-none"),
         pointer_width: 64,
@@ -27,4 +27,4 @@ pub fn target() -> Target {
             ..TargetOptions::default()
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_pc_windows_gnullvm.rs

@@ -1,7 +1,7 @@
 use crate::spec::cow;
 use crate::spec::{base, Target};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let mut base = base::windows_gnullvm::opts();
     base.max_atomic_width = Some(128);
     base.features = cow!("+v8a,+neon,+fp-armv8");
@@ -14,4 +14,4 @@ pub fn target() -> Target {
         arch: cow!("aarch64"),
         options: base,
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_pc_windows_msvc.rs

@@ -1,7 +1,7 @@
 use crate::spec::cow;
 use crate::spec::{base, Target};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let mut base = base::windows_msvc::opts();
     base.max_atomic_width = Some(128);
     base.features = cow!("+v8a,+neon,+fp-armv8");
@@ -13,4 +13,4 @@ pub fn target() -> Target {
         arch: cow!("aarch64"),
         options: base,
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_unknown_freebsd.rs

@@ -1,7 +1,7 @@
 use crate::spec::cow;
 use crate::spec::{base, SanitizerSet, StackProbeType, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     Target {
         llvm_target: cow!("aarch64-unknown-freebsd"),
         pointer_width: 64,
@@ -18,4 +18,4 @@ pub fn target() -> Target {
             ..base::freebsd::opts()
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_unknown_fuchsia.rs

@@ -1,7 +1,7 @@
 use crate::spec::cow;
 use crate::spec::{base, SanitizerSet, StackProbeType, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     Target {
         llvm_target: cow!("aarch64-unknown-fuchsia"),
         pointer_width: 64,
@@ -17,4 +17,4 @@ pub fn target() -> Target {
             ..base::fuchsia::opts()
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_unknown_hermit.rs

@@ -1,7 +1,7 @@
 use crate::spec::cow;
 use crate::spec::{base, StackProbeType, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     Target {
         llvm_target: cow!("aarch64-unknown-hermit"),
         pointer_width: 64,
@@ -14,4 +14,4 @@ pub fn target() -> Target {
             ..base::hermit::opts()
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_unknown_illumos.rs

@@ -3,7 +3,7 @@ use crate::spec::{base, Cc, LinkerFlavor, SanitizerSet, Target, TargetOptions};
 
 use std::sync::LazyLock;
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     let mut base = base::illumos::opts();
     base.pre_link_args =
         LazyLock::new(|| TargetOptions::link_args(LinkerFlavor::Unix(Cc::Yes), &["-std=c99"]));
@@ -20,4 +20,4 @@ pub fn target() -> Target {
         arch: cow!("aarch64"),
         options: base,
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu.rs

@@ -1,7 +1,7 @@
 use crate::spec::cow;
 use crate::spec::{base, SanitizerSet, StackProbeType, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     Target {
         llvm_target: cow!("aarch64-unknown-linux-gnu"),
         pointer_width: 64,
@@ -23,4 +23,4 @@ pub fn target() -> Target {
             ..base::linux_gnu::opts()
         },
     }
-}
+};

compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu_ilp32.rs

@@ -1,7 +1,7 @@
 use crate::spec::cow;
 use crate::spec::{base, StackProbeType, Target, TargetOptions};
 
-pub fn target() -> Target {
+pub static TARGET: Target = {
     Target {
         llvm_target: cow!("aarch64-unknown-linux-gnu_ilp32"),
         pointer_width: 32,
@@ -16,4 +16,4 @@ pub fn target() -> Target {
             ..base::linux_gnu::opts()
         },
     }
-}
+};