Support for Harvey. Harvey is Plan 9 with GPL.

src/librustc_target/spec/harvey_base.rs

@@ -0,0 +1,33 @@
+use crate::spec::{LinkArgs, LinkerFlavor, RelroLevel, TargetOptions};
+
+pub fn opts() -> TargetOptions {
+    let mut args = LinkArgs::new();
+    args.insert(
+        LinkerFlavor::Gcc,
+        vec![
+            // We want to be able to strip as much executable code as possible
+            // from the linker command line, and this flag indicates to the
+            // linker that it can avoid linking in dynamic libraries that don't
+            // actually satisfy any symbols up to that point (as with many other
+            // resolutions the linker does). This option only applies to all
+            // following libraries so we're sure to pass it as one of the first
+            // arguments.
+            "-Wl,--as-needed".to_string(),
+            // Always enable NX protection when it is available
+            "-Wl,-z,noexecstack".to_string(),
+        ],
+    );
+
+    TargetOptions {
+        dynamic_linking: false,
+        executables: true,
+        target_family: Some("unix".to_string()),
+        linker_is_gnu: true,
+        has_rpath: true,
+        pre_link_args: args,
+        position_independent_executables: true,
+        relro_level: RelroLevel::Full,
+        has_elf_tls: false,
+        ..Default::default()
+    }
+}

src/librustc_target/spec/mod.rs

@@ -57,6 +57,7 @@ mod freebsd_base;
 mod freestanding_base;
 mod fuchsia_base;
 mod haiku_base;
+mod harvey_base;
 mod hermit_base;
 mod hermit_kernel_base;
 mod illumos_base;
@@ -574,6 +575,8 @@ supported_targets! {
     ("i686-unknown-haiku", i686_unknown_haiku),
     ("x86_64-unknown-haiku", x86_64_unknown_haiku),
 
+    ("x86_64-unknown-harvey", x86_64_unknown_harvey),
+
     ("x86_64-apple-darwin", x86_64_apple_darwin),
     ("i686-apple-darwin", i686_apple_darwin),
 

src/librustc_target/spec/x86_64_harvey.rs

@@ -0,0 +1,32 @@
+// This defines the x86_64 target for the Harvey Kernel. See the harvey-kernel-base module for
+// generic Harvey kernel options. Note that in Harvey, as in Plan 9 and Go, we call x86_64
+// amd64.
+
+use crate::spec::{CodeModel, LinkerFlavor, Target, TargetResult};
+
+pub fn target() -> TargetResult {
+    let mut base = super::harvey_kernel_base::opts();
+    base.cpu = "x86-64".to_string();
+    base.max_atomic_width = Some(64);
+    base.features =
+        "-mmx,-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-3dnow,-3dnowa,-avx,-avx2,+soft-float"
+            .to_string();
+    base.code_model = Some(CodeModel::Kernel);
+    base.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap().push("-m64".to_string());
+
+    Ok(Target {
+        llvm_target: "x86_64-elf".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
+        data_layout: "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+            .to_string(),
+        target_os: "none".to_string(),
+        target_env: "gnu".to_string(),
+        target_vendor: "unknown".to_string(),
+        arch: "x86_64".to_string(),
+        linker_flavor: LinkerFlavor::Gcc,
+
+        options: base,
+    })
+}

src/librustc_target/spec/x86_64_unknown_harvey.rs

@@ -0,0 +1,24 @@
+use crate::spec::{LinkerFlavor, Target, TargetResult};
+
+pub fn target() -> TargetResult {
+    let mut base = super::harvey_base::opts();
+    base.cpu = "x86-64".to_string();
+    base.max_atomic_width = Some(64);
+    base.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap().push("-m64".to_string());
+    base.stack_probes = true;
+
+    Ok(Target {
+        llvm_target: "x86_64-unknown-harvey-gnu".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
+        data_layout: "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+            .to_string(),
+        arch: "x86_64".to_string(),
+        target_os: "harvey".to_string(),
+        target_env: "gnu".to_string(),
+        target_vendor: "unknown".to_string(),
+        linker_flavor: LinkerFlavor::Gcc,
+        options: base,
+    })
+}