Stop using xargo for building the sysroot

It is currently broken. (see https://github.com/japaric/xargo/issues/227)

This makes it easier to for example patch whole crates away.

8 files changed, 481 insertions, 0 deletions

diff --git a/build_sysroot/Cargo.toml b/build_sysroot/Cargo.toml
new file mode 100644
index 00000000000..d4873602d4d
--- /dev/null
+++ b/build_sysroot/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+authors = ["bjorn3 <bjorn3@users.noreply.github.com>"]
+name = "sysroot"
+version = "0.0.0"
+
+[dependencies]
+core = { path = "./sysroot_src/src/libcore" }
+compiler_builtins = "0.1"
+alloc = { path = "./sysroot_src/src/liballoc" }
+
+alloc_system = { path = "./alloc_system" }
+
+[patch.crates-io]
+rustc-std-workspace-core = { path = "./sysroot_src/src/tools/rustc-std-workspace-core" }
+compiler_builtins = { path = "./compiler_builtins" }
diff --git a/build_sysroot/alloc_system/Cargo.toml b/build_sysroot/alloc_system/Cargo.toml
new file mode 100644
index 00000000000..221faab32bd
--- /dev/null
+++ b/build_sysroot/alloc_system/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+authors = ["The Rust Project Developers", "bjorn3 (edited to be usable outside the rust source)"]
+name = "alloc_system"
+version = "0.0.0"
+[lib]
+name = "alloc_system"
+path = "lib.rs"
+test = false
+doc = false
+[dependencies]
+core = { path = "../sysroot_src/src/libcore" }
+libc = { version = "0.2.43", features = ['rustc-dep-of-std'], default-features = false }
+compiler_builtins = "0.1"
diff --git a/build_sysroot/alloc_system/lib.rs b/build_sysroot/alloc_system/lib.rs
new file mode 100644
index 00000000000..74b52a6497e
--- /dev/null
+++ b/build_sysroot/alloc_system/lib.rs
@@ -0,0 +1,365 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+#![no_std]
+#![allow(unused_attributes)]
+#![unstable(feature = "alloc_system",
+            reason = "this library is unlikely to be stabilized in its current \
+                      form or name",
+            issue = "32838")]
+#![feature(allocator_api)]
+#![feature(core_intrinsics)]
+#![feature(nll)]
+#![feature(staged_api)]
+#![feature(rustc_attrs)]
+#![cfg_attr(
+    all(target_arch = "wasm32", not(target_os = "emscripten")),
+    feature(integer_atomics, stdsimd)
+)]
+#![cfg_attr(any(unix, target_os = "cloudabi", target_os = "redox"), feature(libc))]
+#![rustc_alloc_kind = "lib"]
+// The minimum alignment guaranteed by the architecture. This value is used to
+// add fast paths for low alignment values.
+#[cfg(all(any(target_arch = "x86",
+              target_arch = "arm",
+              target_arch = "mips",
+              target_arch = "powerpc",
+              target_arch = "powerpc64",
+              target_arch = "asmjs",
+              target_arch = "wasm32")))]
+#[allow(dead_code)]
+const MIN_ALIGN: usize = 8;
+#[cfg(all(any(target_arch = "x86_64",
+              target_arch = "aarch64",
+              target_arch = "mips64",
+              target_arch = "s390x",
+              target_arch = "sparc64")))]
+#[allow(dead_code)]
+const MIN_ALIGN: usize = 16;
+use core::alloc::{Alloc, GlobalAlloc, AllocErr, Layout};
+use core::ptr::NonNull;
+/// The default memory allocator provided by the operating system.
+///
+/// This is based on `malloc` on Unix platforms and `HeapAlloc` on Windows,
+/// plus related functions.
+///
+/// This type can be used in a `static` item
+/// with the `#[global_allocator]` attribute
+/// to force the global allocator to be the system’s one.
+/// (The default is jemalloc for executables, on some platforms.)
+///
+/// ```rust
+/// use std::alloc::System;
+///
+/// #[global_allocator]
+/// static A: System = System;
+///
+/// fn main() {
+///     let a = Box::new(4); // Allocates from the system allocator.
+///     println!("{}", a);
+/// }
+/// ```
+///
+/// It can also be used directly to allocate memory
+/// independently of the standard library’s global allocator.
+#[stable(feature = "alloc_system_type", since = "1.28.0")]
+pub struct System;
+#[unstable(feature = "allocator_api", issue = "32838")]
+unsafe impl Alloc for System {
+    #[inline]
+    unsafe fn alloc(&mut self, layout: Layout) -> Result<NonNull<u8>, AllocErr> {
+        NonNull::new(GlobalAlloc::alloc(self, layout)).ok_or(AllocErr)
+    }
+    #[inline]
+    unsafe fn alloc_zeroed(&mut self, layout: Layout) -> Result<NonNull<u8>, AllocErr> {
+        NonNull::new(GlobalAlloc::alloc_zeroed(self, layout)).ok_or(AllocErr)
+    }
+    #[inline]
+    unsafe fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout) {
+        GlobalAlloc::dealloc(self, ptr.as_ptr(), layout)
+    }
+    #[inline]
+    unsafe fn realloc(&mut self,
+                      ptr: NonNull<u8>,
+                      layout: Layout,
+                      new_size: usize) -> Result<NonNull<u8>, AllocErr> {
+        NonNull::new(GlobalAlloc::realloc(self, ptr.as_ptr(), layout, new_size)).ok_or(AllocErr)
+    }
+}
+#[cfg(any(windows, unix, target_os = "cloudabi", target_os = "redox"))]
+mod realloc_fallback {
+    use core::alloc::{GlobalAlloc, Layout};
+    use core::cmp;
+    use core::ptr;
+    impl super::System {
+        pub(crate) unsafe fn realloc_fallback(&self, ptr: *mut u8, old_layout: Layout,
+                                              new_size: usize) -> *mut u8 {
+            // Docs for GlobalAlloc::realloc require this to be valid:
+            let new_layout = Layout::from_size_align_unchecked(new_size, old_layout.align());
+            let new_ptr = GlobalAlloc::alloc(self, new_layout);
+            if !new_ptr.is_null() {
+                let size = cmp::min(old_layout.size(), new_size);
+                ptr::copy_nonoverlapping(ptr, new_ptr, size);
+                GlobalAlloc::dealloc(self, ptr, old_layout);
+            }
+            new_ptr
+        }
+    }
+}
+#[cfg(any(unix, target_os = "cloudabi", target_os = "redox"))]
+mod platform {
+    extern crate libc;
+    use core::ptr;
+    use MIN_ALIGN;
+    use System;
+    use core::alloc::{GlobalAlloc, Layout};
+    #[stable(feature = "alloc_system_type", since = "1.28.0")]
+    unsafe impl GlobalAlloc for System {
+        #[inline]
+        unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+            if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
+                libc::malloc(layout.size()) as *mut u8
+            } else {
+                #[cfg(target_os = "macos")]
+                {
+                    if layout.align() > (1 << 31) {
+                        return ptr::null_mut()
+                    }
+                }
+                aligned_malloc(&layout)
+            }
+        }
+        #[inline]
+        unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
+            if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
+                libc::calloc(layout.size(), 1) as *mut u8
+            } else {
+                let ptr = self.alloc(layout.clone());
+                if !ptr.is_null() {
+                    ptr::write_bytes(ptr, 0, layout.size());
+                }
+                ptr
+            }
+        }
+        #[inline]
+        unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
+            libc::free(ptr as *mut libc::c_void)
+        }
+        #[inline]
+        unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
+            if layout.align() <= MIN_ALIGN && layout.align() <= new_size {
+                libc::realloc(ptr as *mut libc::c_void, new_size) as *mut u8
+            } else {
+                self.realloc_fallback(ptr, layout, new_size)
+            }
+        }
+    }
+    #[cfg(any(target_os = "android",
+              target_os = "hermit",
+              target_os = "redox",
+              target_os = "solaris"))]
+    #[inline]
+    unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
+        // On android we currently target API level 9 which unfortunately
+        // doesn't have the `posix_memalign` API used below. Instead we use
+        // `memalign`, but this unfortunately has the property on some systems
+        // where the memory returned cannot be deallocated by `free`!
+        //
+        // Upon closer inspection, however, this appears to work just fine with
+        // Android, so for this platform we should be fine to call `memalign`
+        // (which is present in API level 9). Some helpful references could
+        // possibly be chromium using memalign [1], attempts at documenting that
+        // memalign + free is ok [2] [3], or the current source of chromium
+        // which still uses memalign on android [4].
+        //
+        // [1]: https://codereview.chromium.org/10796020/
+        // [2]: https://code.google.com/p/android/issues/detail?id=35391
+        // [3]: https://bugs.chromium.org/p/chromium/issues/detail?id=138579
+        // [4]: https://chromium.googlesource.com/chromium/src/base/+/master/
+        //                                       /memory/aligned_memory.cc
+        libc::memalign(layout.align(), layout.size()) as *mut u8
+    }
+    #[cfg(not(any(target_os = "android",
+                  target_os = "hermit",
+                  target_os = "redox",
+                  target_os = "solaris")))]
+    #[inline]
+    unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
+        let mut out = ptr::null_mut();
+        let ret = libc::posix_memalign(&mut out, layout.align(), layout.size());
+        if ret != 0 {
+            ptr::null_mut()
+        } else {
+            out as *mut u8
+        }
+    }
+}
+#[cfg(windows)]
+#[allow(nonstandard_style)]
+mod platform {
+    use MIN_ALIGN;
+    use System;
+    use core::alloc::{GlobalAlloc, Layout};
+    type LPVOID = *mut u8;
+    type HANDLE = LPVOID;
+    type SIZE_T = usize;
+    type DWORD = u32;
+    type BOOL = i32;
+    extern "system" {
+        fn GetProcessHeap() -> HANDLE;
+        fn HeapAlloc(hHeap: HANDLE, dwFlags: DWORD, dwBytes: SIZE_T) -> LPVOID;
+        fn HeapReAlloc(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID, dwBytes: SIZE_T) -> LPVOID;
+        fn HeapFree(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID) -> BOOL;
+        fn GetLastError() -> DWORD;
+    }
+    #[repr(C)]
+    struct Header(*mut u8);
+    const HEAP_ZERO_MEMORY: DWORD = 0x00000008;
+    unsafe fn get_header<'a>(ptr: *mut u8) -> &'a mut Header {
+        &mut *(ptr as *mut Header).offset(-1)
+    }
+    unsafe fn align_ptr(ptr: *mut u8, align: usize) -> *mut u8 {
+        let aligned = ptr.add(align - (ptr as usize & (align - 1)));
+        *get_header(aligned) = Header(ptr);
+        aligned
+    }
+    #[inline]
+    unsafe fn allocate_with_flags(layout: Layout, flags: DWORD) -> *mut u8 {
+        let ptr = if layout.align() <= MIN_ALIGN {
+            HeapAlloc(GetProcessHeap(), flags, layout.size())
+        } else {
+            let size = layout.size() + layout.align();
+            let ptr = HeapAlloc(GetProcessHeap(), flags, size);
+            if ptr.is_null() {
+                ptr
+            } else {
+                align_ptr(ptr, layout.align())
+            }
+        };
+        ptr as *mut u8
+    }
+    #[stable(feature = "alloc_system_type", since = "1.28.0")]
+    unsafe impl GlobalAlloc for System {
+        #[inline]
+        unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+            allocate_with_flags(layout, 0)
+        }
+        #[inline]
+        unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
+            allocate_with_flags(layout, HEAP_ZERO_MEMORY)
+        }
+        #[inline]
+        unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+            if layout.align() <= MIN_ALIGN {
+                let err = HeapFree(GetProcessHeap(), 0, ptr as LPVOID);
+                debug_assert!(err != 0, "Failed to free heap memory: {}",
+                              GetLastError());
+            } else {
+                let header = get_header(ptr);
+                let err = HeapFree(GetProcessHeap(), 0, header.0 as LPVOID);
+                debug_assert!(err != 0, "Failed to free heap memory: {}",
+                              GetLastError());
+            }
+        }
+        #[inline]
+        unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
+            if layout.align() <= MIN_ALIGN {
+                HeapReAlloc(GetProcessHeap(), 0, ptr as LPVOID, new_size) as *mut u8
+            } else {
+                self.realloc_fallback(ptr, layout, new_size)
+            }
+        }
+    }
+}
+// This is an implementation of a global allocator on the wasm32 platform when
+// emscripten is not in use. In that situation there's no actual runtime for us
+// to lean on for allocation, so instead we provide our own!
+//
+// The wasm32 instruction set has two instructions for getting the current
+// amount of memory and growing the amount of memory. These instructions are the
+// foundation on which we're able to build an allocator, so we do so! Note that
+// the instructions are also pretty "global" and this is the "global" allocator
+// after all!
+//
+// The current allocator here is the `dlmalloc` crate which we've got included
+// in the rust-lang/rust repository as a submodule. The crate is a port of
+// dlmalloc.c from C to Rust and is basically just so we can have "pure Rust"
+// for now which is currently technically required (can't link with C yet).
+//
+// The crate itself provides a global allocator which on wasm has no
+// synchronization as there are no threads!
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
+mod platform {
+    extern crate dlmalloc;
+    use core::alloc::{GlobalAlloc, Layout};
+    use System;
+    static mut DLMALLOC: dlmalloc::Dlmalloc = dlmalloc::DLMALLOC_INIT;
+    #[stable(feature = "alloc_system_type", since = "1.28.0")]
+    unsafe impl GlobalAlloc for System {
+        #[inline]
+        unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+            let _lock = lock::lock();
+            DLMALLOC.malloc(layout.size(), layout.align())
+        }
+        #[inline]
+        unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
+            let _lock = lock::lock();
+            DLMALLOC.calloc(layout.size(), layout.align())
+        }
+        #[inline]
+        unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+            let _lock = lock::lock();
+            DLMALLOC.free(ptr, layout.size(), layout.align())
+        }
+        #[inline]
+        unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
+            let _lock = lock::lock();
+            DLMALLOC.realloc(ptr, layout.size(), layout.align(), new_size)
+        }
+    }
+    #[cfg(target_feature = "atomics")]
+    mod lock {
+        use core::arch::wasm32;
+        use core::sync::atomic::{AtomicI32, Ordering::SeqCst};
+        static LOCKED: AtomicI32 = AtomicI32::new(0);
+        pub struct DropLock;
+        pub fn lock() -> DropLock {
+            loop {
+                if LOCKED.swap(1, SeqCst) == 0 {
+                    return DropLock
+                }
+                unsafe {
+                    let r = wasm32::atomic::wait_i32(
+                        &LOCKED as *const AtomicI32 as *mut i32,
+                        1,  // expected value
+                        -1, // timeout
+                    );
+                    debug_assert!(r == 0 || r == 1);
+                }
+            }
+        }
+        impl Drop for DropLock {
+            fn drop(&mut self) {
+                let r = LOCKED.swap(0, SeqCst);
+                debug_assert_eq!(r, 1);
+                unsafe {
+                    wasm32::atomic::wake(
+                        &LOCKED as *const AtomicI32 as *mut i32,
+                        1, // only one thread
+                    );
+                }
+            }
+        }
+    }
+    #[cfg(not(target_feature = "atomics"))]
+    mod lock {
+        #[inline]
+        pub fn lock() {} // no atomics, no threads, that's easy!
+    }
+}
diff --git a/build_sysroot/build_sysroot.sh b/build_sysroot/build_sysroot.sh
new file mode 100755
index 00000000000..38608e02163
--- /dev/null
+++ b/build_sysroot/build_sysroot.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+set -e
+cd $(dirname "$0")
+
+# Cleanup for previous run
+cargo clean
+rm Cargo.lock 2>/dev/null || true
+rm -r sysroot 2>/dev/null || true
+
+# FIXME find a better way to get the target triple
+unamestr=`uname`
+if [[ "$unamestr" == 'Linux' ]]; then
+   TARGET_TRIPLE='x86_64-unknown-linux-gnu'
+elif [[ "$unamestr" == 'Darwin' ]]; then
+   TARGET_TRIPLE='x86_64-apple-darwin'
+else
+   echo "Unsupported os"
+   exit 1
+fi
+
+# Build libs
+export RUSTFLAGS="$RUSTFLAGS -Z force-unstable-if-unmarked --sysroot ../"
+if [[ "$1" == "--release" ]]; then
+    channel='release'
+    RUSTFLAGS="$RUSTFLAGS -Zmir-opt-level=3" cargo build --target $TARGET_TRIPLE --release
+else
+    channel='debug'
+    cargo build --target $TARGET_TRIPLE
+fi
+
+# Copy files to sysroot
+mkdir -p sysroot/lib/rustlib/$TARGET_TRIPLE/lib/
+cp target/$TARGET_TRIPLE/$channel/deps/*.rlib sysroot/lib/rustlib/$TARGET_TRIPLE/lib/
diff --git a/build_sysroot/compiler_builtins/Cargo.toml b/build_sysroot/compiler_builtins/Cargo.toml
new file mode 100644
index 00000000000..724a637a201
--- /dev/null
+++ b/build_sysroot/compiler_builtins/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "compiler_builtins"
+# Make sure the `compiler_builtins` from crates.io doesn't take precedence over this
+# replacement by specifying a higher version than the one on crates.io.
+version = "0.1.100"
+authors = ["bjorn3 <bjorn3@users.noreply.github.com>"]
+edition = "2018"
+
+[lib]
+name = "compiler_builtins"
+path = "lib.rs"
+test = false
+doc = false
+
+[dependencies]
+core = { path = "../sysroot_src/src/libcore" }
+
+[features]
+rustc-dep-of-std = []
+c = []
diff --git a/build_sysroot/compiler_builtins/lib.rs b/build_sysroot/compiler_builtins/lib.rs
new file mode 100644
index 00000000000..90a118deeef
--- /dev/null
+++ b/build_sysroot/compiler_builtins/lib.rs
@@ -0,0 +1,3 @@
+#![feature(compiler_builtins)]
+#![compiler_builtins]
+#![no_std]
diff --git a/build_sysroot/prepare_sysroot_src.sh b/build_sysroot/prepare_sysroot_src.sh
new file mode 100755
index 00000000000..fceccdb4dea
--- /dev/null
+++ b/build_sysroot/prepare_sysroot_src.sh
@@ -0,0 +1,31 @@
+#!/bin/bash
+set -e
+cd $(dirname "$0")
+
+SRC_DIR=$(dirname $(rustup which rustc))"/../lib/rustlib/src/rust/"
+DST_DIR="sysroot_src"
+
+if [ ! -e $SRC_DIR ]; then
+    echo "Please install rust-src component"
+    exit 1
+fi
+
+rm -rf $DST_DIR
+mkdir -p $DST_DIR/src
+cp -r $SRC_DIR/src $DST_DIR/
+
+pushd $DST_DIR
+echo "[GIT] init"
+git init
+echo "[GIT] add"
+git add .
+echo "[GIT] commit"
+git commit -m "Initial commit" -q
+for file in $(ls ../../patches/ | grep -v patcha); do
+echo "[GIT] apply" $file
+git apply ../../patches/$file
+git commit -am "Patch $file"
+done
+popd
+
+echo "Successfully prepared libcore for building"
diff --git a/build_sysroot/src/lib.rs b/build_sysroot/src/lib.rs
new file mode 100644
index 00000000000..0c9ac1ac8e4
--- /dev/null
+++ b/build_sysroot/src/lib.rs
@@ -0,0 +1 @@
+#![no_std]