Merge pull request #448 from stefson/rust-999

dev-lang/rust: add beta channel ebuild

2 files changed, 860 insertions, 0 deletions

diff --git a/dev-lang/rust/files/pr65474.patch b/dev-lang/rust/files/pr65474.patch
new file mode 100644
index 0000000..34cbb4d
--- /dev/null
+++ b/dev-lang/rust/files/pr65474.patch
@@ -0,0 +1,512 @@
+From 3a05616cb6b6df75fc54094de7f3d4b161ed8521 Mon Sep 17 00:00:00 2001
+From: Josh Stone <jistone@redhat.com>
+Date: Thu, 26 Sep 2019 14:44:08 -0700
+Subject: [PATCH 1/3] minimize the rust-std component
+
+This splits out a rustc-dev component with the compiler crates, and
+keeps the status quo of default installed files on nightly. The default
+changing to not install compiler libraries by default is left for a
+future pull request.
+
+However, on stable and beta, this does remove the compiler libraries
+from the set of libraries installed by default, as they are never needed
+there (per our stability story, they "cannot" be used).
+---
+ src/bootstrap/builder.rs             |   1 +
+ src/bootstrap/dist.rs                | 129 ++++++++++++++++++++-------
+ src/tools/build-manifest/src/main.rs |  15 ++++
+ 3 files changed, 112 insertions(+), 33 deletions(-)
+
+diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
+index 0caf2d9b6db5..7e3ae7f2cc90 100644
+--- a/src/bootstrap/builder.rs
++++ b/src/bootstrap/builder.rs
+@@ -443,6 +443,7 @@ impl<'a> Builder<'a> {
+                 dist::Rustc,
+                 dist::DebuggerScripts,
+                 dist::Std,
++                dist::RustcDev,
+                 dist::Analysis,
+                 dist::Src,
+                 dist::PlainSourceTarball,
+diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
+index d9dff77a30e6..e5a43dcb29f6 100644
+--- a/src/bootstrap/dist.rs
++++ b/src/bootstrap/dist.rs
+@@ -637,6 +637,28 @@ impl Step for DebuggerScripts {
+     }
+ }
+ 
++fn skip_host_target_lib(builder: &Builder<'_>, compiler: Compiler) -> bool {
++    // The only true set of target libraries came from the build triple, so
++    // let's reduce redundant work by only producing archives from that host.
++    if compiler.host != builder.config.build {
++        builder.info("\tskipping, not a build host");
++        true
++    } else {
++        false
++    }
++}
++
++/// Copy stamped files into an image's `target/lib` directory.
++fn copy_target_libs(builder: &Builder<'_>, target: &str, image: &Path, stamp: &Path) {
++    let dst = image.join("lib/rustlib").join(target).join("lib");
++    t!(fs::create_dir_all(&dst));
++    for (path, host) in builder.read_stamp_file(stamp) {
++        if !host || builder.config.build == target {
++            builder.copy(&path, &dst.join(path.file_name().unwrap()));
++        }
++    }
++}
++
+ #[derive(Debug, PartialOrd, Ord, Copy, Clone, Hash, PartialEq, Eq)]
+ pub struct Std {
+     pub compiler: Compiler,
+@@ -667,44 +689,19 @@ impl Step for Std {
+         let target = self.target;
+ 
+         let name = pkgname(builder, "rust-std");
+-
+-        // The only true set of target libraries came from the build triple, so
+-        // let's reduce redundant work by only producing archives from that host.
+-        if compiler.host != builder.config.build {
+-            builder.info("\tskipping, not a build host");
+-            return distdir(builder).join(format!("{}-{}.tar.gz", name, target));
++        let archive = distdir(builder).join(format!("{}-{}.tar.gz", name, target));
++        if skip_host_target_lib(builder, compiler) {
++            return archive;
+         }
+ 
+-        // We want to package up as many target libraries as possible
+-        // for the `rust-std` package, so if this is a host target we
+-        // depend on librustc and otherwise we just depend on libtest.
+-        if builder.hosts.iter().any(|t| t == target) {
+-            builder.ensure(compile::Rustc { compiler, target });
+-        } else {
+-            builder.ensure(compile::Std { compiler, target });
+-        }
++        builder.ensure(compile::Std { compiler, target });
+ 
+         let image = tmpdir(builder).join(format!("{}-{}-image", name, target));
+         let _ = fs::remove_dir_all(&image);
+ 
+-        let dst = image.join("lib/rustlib").join(target);
+-        t!(fs::create_dir_all(&dst));
+-        let mut src = builder.sysroot_libdir(compiler, target).to_path_buf();
+-        src.pop(); // Remove the trailing /lib folder from the sysroot_libdir
+-        builder.cp_filtered(&src, &dst, &|path| {
+-            if let Some(name) = path.file_name().and_then(|s| s.to_str()) {
+-                if name == builder.config.rust_codegen_backends_dir.as_str() {
+-                    return false
+-                }
+-                if name == "bin" {
+-                    return false
+-                }
+-                if name.contains("LLVM") {
+-                    return false
+-                }
+-            }
+-            true
+-        });
++        let compiler_to_use = builder.compiler_for(compiler.stage, compiler.host, target);
++        let stamp = compile::libstd_stamp(builder, compiler_to_use, target);
++        copy_target_libs(builder, &target, &image, &stamp);
+ 
+         let mut cmd = rust_installer(builder);
+         cmd.arg("generate")
+@@ -723,7 +720,73 @@ impl Step for Std {
+         let _time = timeit(builder);
+         builder.run(&mut cmd);
+         builder.remove_dir(&image);
+-        distdir(builder).join(format!("{}-{}.tar.gz", name, target))
++        archive
++    }
++}
++
++#[derive(Debug, PartialOrd, Ord, Copy, Clone, Hash, PartialEq, Eq)]
++pub struct RustcDev {
++    pub compiler: Compiler,
++    pub target: Interned<String>,
++}
++
++impl Step for RustcDev {
++    type Output = PathBuf;
++    const DEFAULT: bool = true;
++    const ONLY_HOSTS: bool = true;
++
++    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
++        run.path("rustc-dev")
++    }
++
++    fn make_run(run: RunConfig<'_>) {
++        run.builder.ensure(RustcDev {
++            compiler: run.builder.compiler_for(
++                run.builder.top_stage,
++                run.builder.config.build,
++                run.target,
++            ),
++            target: run.target,
++        });
++    }
++
++    fn run(self, builder: &Builder<'_>) -> PathBuf {
++        let compiler = self.compiler;
++        let target = self.target;
++
++        let name = pkgname(builder, "rustc-dev");
++        let archive = distdir(builder).join(format!("{}-{}.tar.gz", name, target));
++        if skip_host_target_lib(builder, compiler) {
++            return archive;
++        }
++
++        builder.ensure(compile::Rustc { compiler, target });
++
++        let image = tmpdir(builder).join(format!("{}-{}-image", name, target));
++        let _ = fs::remove_dir_all(&image);
++
++        let compiler_to_use = builder.compiler_for(compiler.stage, compiler.host, target);
++        let stamp = compile::librustc_stamp(builder, compiler_to_use, target);
++        copy_target_libs(builder, &target, &image, &stamp);
++
++        let mut cmd = rust_installer(builder);
++        cmd.arg("generate")
++           .arg("--product-name=Rust")
++           .arg("--rel-manifest-dir=rustlib")
++           .arg("--success-message=Rust-is-ready-to-develop.")
++           .arg("--image-dir").arg(&image)
++           .arg("--work-dir").arg(&tmpdir(builder))
++           .arg("--output-dir").arg(&distdir(builder))
++           .arg(format!("--package-name={}-{}", name, target))
++           .arg(format!("--component-name=rustc-dev-{}", target))
++           .arg("--legacy-manifest-dirs=rustlib,cargo");
++
++        builder.info(&format!("Dist rustc-dev stage{} ({} -> {})",
++            compiler.stage, &compiler.host, target));
++        let _time = timeit(builder);
++        builder.run(&mut cmd);
++        builder.remove_dir(&image);
++        archive
+     }
+ }
+ 
+diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
+index f41e7dd17ede..97e758f9b823 100644
+--- a/src/tools/build-manifest/src/main.rs
++++ b/src/tools/build-manifest/src/main.rs
+@@ -399,6 +399,7 @@ impl Builder {
+     fn add_packages_to(&mut self, manifest: &mut Manifest) {
+         let mut package = |name, targets| self.package(name, &mut manifest.pkg, targets);
+         package("rustc", HOSTS);
++        package("rustc-dev", HOSTS);
+         package("cargo", HOSTS);
+         package("rust-mingw", MINGW);
+         package("rust-std", TARGETS);
+@@ -481,6 +482,15 @@ impl Builder {
+             components.push(host_component("rust-mingw"));
+         }
+ 
++        // The compiler libraries are not stable for end users, but `rustc-dev` was only recently
++        // split out of `rust-std`. We'll include it by default as a transition for nightly users,
++        // but ship it as an optional component on the beta and stable channels.
++        if self.rust_release == "nightly" {
++            components.push(host_component("rustc-dev"));
++        } else {
++            extensions.push(host_component("rustc-dev"));
++        }
++
+         // Tools are always present in the manifest,
+         // but might be marked as unavailable if they weren't built.
+         extensions.extend(vec![
+@@ -498,6 +508,11 @@ impl Builder {
+                 .filter(|&&target| target != host)
+                 .map(|target| Component::from_str("rust-std", target))
+         );
++        extensions.extend(
++            HOSTS.iter()
++                .filter(|&&target| target != host)
++                .map(|target| Component::from_str("rustc-dev", target))
++        );
+         extensions.push(Component::from_str("rust-src", "*"));
+ 
+         // If the components/extensions don't actually exist for this
+
+From 4c906dc84ec78fad35405d5c0f2b2d58f9f26288 Mon Sep 17 00:00:00 2001
+From: Josh Stone <jistone@redhat.com>
+Date: Mon, 7 Oct 2019 15:49:51 -0700
+Subject: [PATCH 2/3] Add rustc-dev to nightly default and complete profiles
+
+---
+ src/tools/build-manifest/src/main.rs | 15 +++++++++++++++
+ 1 file changed, 15 insertions(+)
+
+diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
+index 97e758f9b823..c0d2deab2f8b 100644
+--- a/src/tools/build-manifest/src/main.rs
++++ b/src/tools/build-manifest/src/main.rs
+@@ -427,6 +427,13 @@ impl Builder {
+             "rls-preview", "rust-src", "llvm-tools-preview",
+             "lldb-preview", "rust-analysis", "miri-preview"
+         ]);
++
++        // The compiler libraries are not stable for end users, but `rustc-dev` was only recently
++        // split out of `rust-std`. We'll include it by default as a transition for nightly users.
++        if self.rust_release == "nightly" {
++            self.extend_profile("default", &mut manifest.profiles, &["rustc-dev"]);
++            self.extend_profile("complete", &mut manifest.profiles, &["rustc-dev"]);
++        }
+     }
+ 
+     fn add_renames_to(&self, manifest: &mut Manifest) {
+@@ -549,6 +556,14 @@ impl Builder {
+         dst.insert(profile_name.to_owned(), pkgs.iter().map(|s| (*s).to_owned()).collect());
+     }
+ 
++    fn extend_profile(&mut self,
++               profile_name: &str,
++               dst: &mut BTreeMap<String, Vec<String>>,
++               pkgs: &[&str]) {
++        dst.get_mut(profile_name).expect("existing profile")
++            .extend(pkgs.iter().map(|s| (*s).to_owned()));
++    }
++
+     fn package(&mut self,
+                pkgname: &str,
+                dst: &mut BTreeMap<String, Package>,
+
+From 7ccf492ae616b4d06eab283ab604938fd234415a Mon Sep 17 00:00:00 2001
+From: Jethro Beekman <jethro@fortanix.com>
+Date: Sat, 12 Oct 2019 16:01:59 +0200
+Subject: [PATCH 3/3] Package non-rust objects
+
+---
+ src/bootstrap/check.rs   |  4 +++
+ src/bootstrap/compile.rs | 63 ++++++++++++++++++++++++++--------------
+ src/bootstrap/lib.rs     |  1 +
+ 3 files changed, 46 insertions(+), 22 deletions(-)
+
+diff --git a/src/bootstrap/check.rs b/src/bootstrap/check.rs
+index cadb9a7e441f..df1c72575846 100644
+--- a/src/bootstrap/check.rs
++++ b/src/bootstrap/check.rs
+@@ -55,6 +55,7 @@ impl Step for Std {
+                   cargo,
+                   args(builder.kind),
+                   &libstd_stamp(builder, compiler, target),
++                  vec![],
+                   true);
+ 
+         let libdir = builder.sysroot_libdir(compiler, target);
+@@ -103,6 +104,7 @@ impl Step for Rustc {
+                   cargo,
+                   args(builder.kind),
+                   &librustc_stamp(builder, compiler, target),
++                  vec![],
+                   true);
+ 
+         let libdir = builder.sysroot_libdir(compiler, target);
+@@ -155,6 +157,7 @@ impl Step for CodegenBackend {
+                   cargo,
+                   args(builder.kind),
+                   &codegen_backend_stamp(builder, compiler, target, backend),
++                  vec![],
+                   true);
+     }
+ }
+@@ -199,6 +202,7 @@ impl Step for Rustdoc {
+                   cargo,
+                   args(builder.kind),
+                   &rustdoc_stamp(builder, compiler, target),
++                  vec![],
+                   true);
+ 
+         let libdir = builder.sysroot_libdir(compiler, target);
+diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
+index 6ea32edfb208..d48927f9bf78 100644
+--- a/src/bootstrap/compile.rs
++++ b/src/bootstrap/compile.rs
+@@ -69,7 +69,7 @@ impl Step for Std {
+             return;
+         }
+ 
+-        builder.ensure(StartupObjects { compiler, target });
++        let mut target_deps = builder.ensure(StartupObjects { compiler, target });
+ 
+         let compiler_to_use = builder.compiler_for(compiler.stage, compiler.host, target);
+         if compiler_to_use != compiler {
+@@ -91,7 +91,7 @@ impl Step for Std {
+             return;
+         }
+ 
+-        copy_third_party_objects(builder, &compiler, target);
++        target_deps.extend(copy_third_party_objects(builder, &compiler, target).into_iter());
+ 
+         let mut cargo = builder.cargo(compiler, Mode::Std, target, "build");
+         std_cargo(builder, &compiler, target, &mut cargo);
+@@ -102,6 +102,7 @@ impl Step for Std {
+                   cargo,
+                   vec![],
+                   &libstd_stamp(builder, compiler, target),
++                  target_deps,
+                   false);
+ 
+         builder.ensure(StdLink {
+@@ -113,9 +114,22 @@ impl Step for Std {
+ }
+ 
+ /// Copies third pary objects needed by various targets.
+-fn copy_third_party_objects(builder: &Builder<'_>, compiler: &Compiler, target: Interned<String>) {
++fn copy_third_party_objects(builder: &Builder<'_>, compiler: &Compiler, target: Interned<String>)
++    -> Vec<PathBuf>
++{
+     let libdir = builder.sysroot_libdir(*compiler, target);
+ 
++    let mut target_deps = vec![];
++
++    let mut copy_and_stamp = |sourcedir: &Path, name: &str| {
++        let target = libdir.join(name);
++        builder.copy(
++            &sourcedir.join(name),
++            &target,
++        );
++        target_deps.push(target);
++    };
++
+     // Copies the crt(1,i,n).o startup objects
+     //
+     // Since musl supports fully static linking, we can cross link for it even
+@@ -123,19 +137,13 @@ fn copy_third_party_objects(builder: &Builder<'_>, compiler: &Compiler, target:
+     // files. As those shipped with glibc won't work, copy the ones provided by
+     // musl so we have them on linux-gnu hosts.
+     if target.contains("musl") {
++        let srcdir = builder.musl_root(target).unwrap().join("lib");
+         for &obj in &["crt1.o", "crti.o", "crtn.o"] {
+-            builder.copy(
+-                &builder.musl_root(target).unwrap().join("lib").join(obj),
+-                &libdir.join(obj),
+-            );
++            copy_and_stamp(&srcdir, obj);
+         }
+     } else if target.ends_with("-wasi") {
+-        for &obj in &["crt1.o"] {
+-            builder.copy(
+-                &builder.wasi_root(target).unwrap().join("lib/wasm32-wasi").join(obj),
+-                &libdir.join(obj),
+-            );
+-        }
++        let srcdir = builder.wasi_root(target).unwrap().join("lib/wasm32-wasi");
++        copy_and_stamp(&srcdir, "crt1.o");
+     }
+ 
+     // Copies libunwind.a compiled to be linked wit x86_64-fortanix-unknown-sgx.
+@@ -145,11 +153,11 @@ fn copy_third_party_objects(builder: &Builder<'_>, compiler: &Compiler, target:
+     // which is provided by std for this target.
+     if target == "x86_64-fortanix-unknown-sgx" {
+         let src_path_env = "X86_FORTANIX_SGX_LIBS";
+-        let obj = "libunwind.a";
+         let src = env::var(src_path_env).expect(&format!("{} not found in env", src_path_env));
+-        let src = Path::new(&src).join(obj);
+-        builder.copy(&src, &libdir.join(obj));
++        copy_and_stamp(Path::new(&src), "libunwind.a");
+     }
++
++    target_deps
+ }
+ 
+ /// Configure cargo to compile the standard library, adding appropriate env vars
+@@ -307,7 +315,7 @@ pub struct StartupObjects {
+ }
+ 
+ impl Step for StartupObjects {
+-    type Output = ();
++    type Output = Vec<PathBuf>;
+ 
+     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+         run.path("src/rtstartup")
+@@ -326,13 +334,15 @@ impl Step for StartupObjects {
+     /// They don't require any library support as they're just plain old object
+     /// files, so we just use the nightly snapshot compiler to always build them (as
+     /// no other compilers are guaranteed to be available).
+-    fn run(self, builder: &Builder<'_>) {
++    fn run(self, builder: &Builder<'_>) -> Vec<PathBuf> {
+         let for_compiler = self.compiler;
+         let target = self.target;
+         if !target.contains("windows-gnu") {
+-            return
++            return vec![]
+         }
+ 
++        let mut target_deps = vec![];
++
+         let src_dir = &builder.src.join("src/rtstartup");
+         let dst_dir = &builder.native_dir(target).join("rtstartup");
+         let sysroot_dir = &builder.sysroot_libdir(for_compiler, target);
+@@ -351,7 +361,9 @@ impl Step for StartupObjects {
+                             .arg(src_file));
+             }
+ 
+-            builder.copy(dst_file, &sysroot_dir.join(file.to_string() + ".o"));
++            let target = sysroot_dir.join(file.to_string() + ".o");
++            builder.copy(dst_file, &target);
++            target_deps.push(target);
+         }
+ 
+         for obj in ["crt2.o", "dllcrt2.o"].iter() {
+@@ -359,8 +371,12 @@ impl Step for StartupObjects {
+                                     builder.cc(target),
+                                     target,
+                                     obj);
+-            builder.copy(&src, &sysroot_dir.join(obj));
++            let target = sysroot_dir.join(obj);
++            builder.copy(&src, &target);
++            target_deps.push(target);
+         }
++
++        target_deps
+     }
+ }
+ 
+@@ -438,6 +454,7 @@ impl Step for Rustc {
+                   cargo,
+                   vec![],
+                   &librustc_stamp(builder, compiler, target),
++                  vec![],
+                   false);
+ 
+         builder.ensure(RustcLink {
+@@ -586,7 +603,7 @@ impl Step for CodegenBackend {
+ 
+         let tmp_stamp = out_dir.join(".tmp.stamp");
+ 
+-        let files = run_cargo(builder, cargo, vec![], &tmp_stamp, false);
++        let files = run_cargo(builder, cargo, vec![], &tmp_stamp, vec![], false);
+         if builder.config.dry_run {
+             return;
+         }
+@@ -954,6 +971,7 @@ pub fn run_cargo(builder: &Builder<'_>,
+                  cargo: Cargo,
+                  tail_args: Vec<String>,
+                  stamp: &Path,
++                 additional_target_deps: Vec<PathBuf>,
+                  is_check: bool)
+     -> Vec<PathBuf>
+ {
+@@ -1070,6 +1088,7 @@ pub fn run_cargo(builder: &Builder<'_>,
+         deps.push((path_to_add.into(), false));
+     }
+ 
++    deps.extend(additional_target_deps.into_iter().map(|d| (d, false)));
+     deps.sort();
+     let mut new_contents = Vec::new();
+     for (dep, proc_macro) in deps.iter() {
+diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
+index 9203a558f646..ad0bdd0f425f 100644
+--- a/src/bootstrap/lib.rs
++++ b/src/bootstrap/lib.rs
+@@ -1144,6 +1144,7 @@ impl Build {
+     pub fn copy(&self, src: &Path, dst: &Path) {
+         if self.config.dry_run { return; }
+         self.verbose_than(1, &format!("Copy {:?} to {:?}", src, dst));
++        if src == dst { return; }
+         let _ = fs::remove_file(&dst);
+         let metadata = t!(src.symlink_metadata());
+         if metadata.file_type().is_symlink() {
diff --git a/dev-lang/rust/rust-999.ebuild b/dev-lang/rust/rust-999.ebuild
new file mode 100644
index 0000000..1e20a71
--- /dev/null
+++ b/dev-lang/rust/rust-999.ebuild
@@ -0,0 +1,348 @@
+# Copyright 1999-2019 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+PYTHON_COMPAT=( python2_7 python3_{5,6,7} pypy )
+
+inherit check-reqs estack flag-o-matic llvm multiprocessing multilib-build python-any-r1 rust-toolchain toolchain-funcs git-r3
+
+SLOT="beta"
+MY_P="rust-beta"
+EGIT_REPO_URI="https://github.com/rust-lang/rust.git"
+EGIT_BRANCH="beta"
+
+EGIT_CHECKOUT_DIR="${MY_P}-src"
+KEYWORDS=""
+
+CHOST_amd64=x86_64-unknown-linux-gnu
+CHOST_x86=i686-unknown-linux-gnu
+CHOST_arm64=aarch64-unknown-linux-gnu
+CHOST_arm=armv7-unknown-linux-gnu
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+RESTRICT="network-sandbox"
+
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARM BPF Hexagon Lanai Mips MSP430
+	NVPTX PowerPC Sparc SystemZ WebAssembly X86 XCore )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD-1 BSD-2 BSD-4 UoI-NCSA"
+
+IUSE="clippy cpu_flags_x86_sse2 debug doc libressl rls rustfmt system-llvm wasm sanitize miri zsh-completion ${ALL_LLVM_TARGETS[*]}"
+
+# Please keep the LLVM dependency block separate. Since LLVM is slotted,
+# we need to *really* make sure we're not pulling one than more slot
+# simultaneously.
+
+# How to use it:
+# 1. List all the working slots (with min versions) in ||, newest first.
+# 2. Update the := to specify *max* version, e.g. < 9.
+# 3. Specify LLVM_MAX_SLOT, e.g. 8.
+LLVM_DEPEND="
+	|| (
+		sys-devel/llvm:9[llvm_targets_WebAssembly?]
+		wasm? ( >=sys-devel/lld-9 )
+	)
+	(
+		sys-devel/llvm:8[llvm_targets_WebAssembly?]
+		wasm? ( >=sys-devel/lld-8 )
+	)
+	<sys-devel/llvm-10:=
+"
+LLVM_MAX_SLOT=9
+
+COMMON_DEPEND="
+	sys-libs/zlib
+	!libressl? ( dev-libs/openssl:0= )
+	libressl? ( dev-libs/libressl:0= )
+	net-libs/libssh2
+	net-libs/http-parser:=
+	net-misc/curl[ssl]
+	system-llvm? (
+		${LLVM_DEPEND}
+	)
+"
+
+DEPEND="${COMMON_DEPEND}
+	${PYTHON_DEPS}
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	dev-util/cmake
+"
+
+RDEPEND="${COMMON_DEPEND}
+	>=app-eselect/eselect-rust-20190311
+	!dev-util/cargo
+	rustfmt? ( !dev-util/rustfmt )
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+	?? ( system-llvm sanitize )
+"
+
+PATCHES=( 
+	"${FILESDIR}"/pr65474.patch
+	)
+
+S="${WORKDIR}/${MY_P}-src"
+
+toml_usex() {
+	usex "$1" true false
+}
+
+pre_build_checks() {
+	CHECKREQS_DISK_BUILD="7G"
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		CHECKREQS_DISK_BUILD="10G"
+	fi
+	eshopts_pop
+	check-reqs_pkg_setup
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	unset SUDO_USER
+
+	pre_build_checks
+	python-any-r1_pkg_setup
+	if use system-llvm; then
+		EGIT_SUBMODULES=( "*" "-src/llvm-project" )
+		llvm_pkg_setup
+	fi
+}
+
+src_prepare() {
+	local rust_stage0_root="${WORKDIR}"/rust-stage0
+
+	default
+}
+
+src_unpack() {
+	git-r3_src_unpack
+}
+
+src_configure() {
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets="${rust_targets},\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets="${rust_targets},\"wasm32-unknown-unknown\""
+	fi
+	rust_targets="${rust_targets#,}"
+
+	local extended="true" tools="\"cargo\","
+	if use clippy; then
+		tools="\"clippy\",$tools"
+	fi
+	if use rls; then
+		tools="\"rls\",\"analysis\",\"src\",$tools"
+	fi
+	if use rustfmt; then
+		tools="\"rustfmt\",$tools"
+	fi
+	if use miri; then
+		tools="\"miri\",$tools"
+	fi
+
+	local rust_stage0_root="${WORKDIR}"/rust-stage0
+
+	rust_target="$(rust_abi)"
+
+	cat <<- EOF > "${S}"/config.toml
+		[llvm]
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		[build]
+		build = "${rust_target}"
+		host = ["${rust_target}"]
+		target = [${rust_targets}]
+		docs = $(toml_usex doc)
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = false
+		sanitizers = $(toml_usex sanitize)
+		extended = ${extended}
+		tools = [${tools}]
+		verbose = 2
+		[install]
+		prefix = "${EPREFIX}/usr"
+		libdir = "$(get_libdir)/${P}"
+		docdir = "share/doc/${P}"
+		mandir = "share/${P}/man"
+		[rust]
+		optimize = $(toml_usex !debug)
+		debuginfo-level = $(usex debug 2 0)
+		debug-assertions = $(toml_usex debug)
+		default-linker = "$(tc-getCC)"
+		rpath = false
+		ignore-git = false
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		llvm-tools = $(usex system-llvm false true)
+	EOF
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		cat <<- EOF >> "${S}"/config.env
+			CFLAGS_${rust_target}=${arch_cflags}
+		EOF
+
+		cat <<- EOF >> "${S}"/config.toml
+			[target.${rust_target}]
+			cc = "$(tc-getBUILD_CC)"
+			cxx = "$(tc-getBUILD_CXX)"
+			linker = "$(tc-getCC)"
+			ar = "$(tc-getAR)"
+		EOF
+		if use system-llvm; then
+			cat <<- EOF >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix "${LLVM_MAX_SLOT}")/bin/llvm-config"
+			EOF
+		fi
+	done
+
+	if use wasm; then
+		cat <<- EOF >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+		EOF
+	fi
+}
+
+src_compile() {
+	env $(cat "${S}"/config.env)\
+		"${EPYTHON}" ./x.py build -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_install() {
+	local rust_target abi_libdir
+
+	env DESTDIR="${D}" "${EPYTHON}" ./x.py install -vv -j$(makeopts_jobs) --config="${S}"/config.toml || die
+
+	mv "${ED}/usr/bin/rustc" "${ED}/usr/bin/rustc-${PV}" || die
+	mv "${ED}/usr/bin/rustdoc" "${ED}/usr/bin/rustdoc-${PV}" || die
+	mv "${ED}/usr/bin/rust-gdb" "${ED}/usr/bin/rust-gdb-${PV}" || die
+	mv "${ED}/usr/bin/rust-gdbgui" "${ED}/usr/bin/rust-gdbgui-${PV}" || die
+	mv "${ED}/usr/bin/rust-lldb" "${ED}/usr/bin/rust-lldb-${PV}" || die
+	mv "${ED}/usr/bin/cargo" "${ED}/usr/bin/cargo-${PV}" || die
+	if use clippy; then
+		mv "${ED}/usr/bin/clippy-driver" "${ED}/usr/bin/clippy-driver-${PV}" || die
+		mv "${ED}/usr/bin/cargo-clippy" "${ED}/usr/bin/cargo-clippy-${PV}" || die
+	fi
+	if use rls; then
+		mv "${ED}/usr/bin/rls" "${ED}/usr/bin/rls-${PV}" || die
+	fi
+	if use rustfmt; then
+		mv "${ED}/usr/bin/rustfmt" "${ED}/usr/bin/rustfmt-${PV}" || die
+		mv "${ED}/usr/bin/cargo-fmt" "${ED}/usr/bin/cargo-fmt-${PV}" || die
+	fi
+	if use miri; then
+		mv "${ED}/usr/bin/miri" "${ED}/usr/bin/miri-${PV}" || die
+		mv "${ED}/usr/bin/cargo-miri" "${ED}/usr/bin/cargo-miri-${PV}" || die
+	fi
+	if ! use zsh-completion; then
+		rm "${ED}/usr/share/zsh/site-functions/_cargo" # fix https://bugs.gentoo.org/675026
+	fi
+
+	# Copy shared library versions of standard libraries for all targets
+	# into the system's abi-dependent lib directories because the rust
+	# installer only does so for the native ABI.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		if [ ${v##*.} = ${DEFAULT_ABI} ]; then
+			continue
+		fi
+		abi_libdir=$(get_abi_LIBDIR ${v##*.})
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		mkdir -p "${ED}/usr/${abi_libdir}/${P}"
+		cp "${ED}/usr/$(get_libdir)/${P}/rustlib/${rust_target}/lib"/*.so \
+		   "${ED}/usr/${abi_libdir}/${P}" || die
+	done
+
+	dodoc COPYRIGHT
+
+	cat <<-EOF > "${T}"/50${P}
+		LDPATH="${EPREFIX}/usr/$(get_libdir)/${P}"
+		MANPATH="${EPREFIX}/usr/share/${P}/man"
+	EOF
+	if use rls; then
+		cat <<-EOF >> "${T}"/50${P}
+		RUST_SRC_PATH="${EPREFIX}/usr/$(get_libdir)/${P}/rustlib/src/rust/src/"
+		EOF
+	fi
+	doenvd "${T}"/50${P}
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-EOF > "${T}/provider-${P}"
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+	EOF
+	echo /usr/bin/cargo >> "${T}/provider-${P}"
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use rls; then
+		echo /usr/bin/rls >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	dodir /etc/env.d/rust
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+}
+
+pkg_postinst() {
+	eselect rust update --if-unset
+
+	elog "Rust installs a helper script for calling GDB and LLDB,"
+	elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+
+	ewarn "cargo is now installed from dev-lang/rust{,-bin} instead of dev-util/cargo."
+	ewarn "This might have resulted in a dangling symlink for /usr/bin/cargo on some"
+	ewarn "systems. This can be resolved by calling 'sudo eselect rust set ${P}'."
+
+	if has_version app-editors/emacs || has_version app-editors/emacs-vcs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+
+	if has_version 'app-shells/zsh'; then
+		elog "install app-shells/rust-zshcomp to get zsh completion for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}