rustc-1.39.0-src.patch

# Add mrustc slice length intrinsics
--- src/libcore/intrinsics.rs
+++ src/libcore/intrinsics.rs
@@ -684,6 +684,10 @@ extern "rust-intrinsic" {
     pub fn size_of_val<T: ?Sized>(_: &T) -> usize;
     pub fn min_align_of_val<T: ?Sized>(_: &T) -> usize;
 
+    /// Obtain the length of a slice pointer
+    #[cfg(rust_compiler="mrustc")]
+    pub fn mrustc_slice_len<T>(pointer: *const [T]) -> usize;
+
     /// Gets a static string slice containing the name of a type.
     pub fn type_name<T: ?Sized>() -> &'static str;
 
--- src/libcore/slice/mod.rs
+++ src/libcore/slice/mod.rs
@@ -66,9 +66,12 @@ impl<T> [T] {
     // SAFETY: const sound because we transmute out the length field as a usize (which it must be)
     #[cfg_attr(not(bootstrap), allow_internal_unstable(const_fn_union))]
     pub const fn len(&self) -> usize {
-        unsafe {
-            crate::ptr::Repr { rust: self }.raw.len
-        }
+        #[cfg(not(rust_compiler="mrustc"))]
+        #[cfg_attr(not(bootstrap), allow_internal_unstable(const_fn_union))]
+        const fn len_inner<T>(s: &[T]) -> usize { unsafe { crate::ptr::Repr { rust: s }.raw.len } };
+        #[cfg(rust_compiler="mrustc")]
+        const fn len_inner<T>(s: &[T]) -> usize { unsafe { crate::intrinsics::mrustc_slice_len(s) } }
+        len_inner(self)
     }
 
     /// Returns `true` if the slice has a length of 0.

#
# Static-link rustc_codegen_llvm so the generated rustc is standalone
# > Note: Interacts with `rustc-1.39.0-overrides.toml`
#
--- src/librustc_interface/util.rs
+++ src/librustc_interface/util.rs
@@ -417,6 +417,8 @@ fn sysroot_candidates() -> Vec<PathBuf> {
 }
 
 pub fn get_codegen_sysroot(backend_name: &str) -> fn() -> Box<dyn CodegenBackend> {
+    #[cfg(rust_compiler="mrustc")]
+    { if(backend_name == "llvm") { extern "Rust" { fn __rustc_codegen_backend() -> Box<dyn CodegenBackend>; } return || unsafe { __rustc_codegen_backend() } } }
     // For now we only allow this function to be called once as it'll dlopen a
     // few things, which seems to work best if we only do that once. In
     // general this assertion never trips due to the once guard in `get_codegen_backend`,

--- src/llvm-project/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
+++ src/llvm-project/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
@@ -16,6 +16,8 @@
 #include "llvm/Demangle/DemangleConfig.h"
 #include "llvm/Demangle/StringView.h"
 #include <array>
+#include <cstdint>
+#include <string>
 
 namespace llvm {
 namespace itanium_demangle {

# Disable most architecture intrinsics
--- src/stdarch/crates/std_detect/src/detect/mod.rs
+++ src/stdarch/crates/std_detect/src/detect/mod.rs
@@ -72,6 +72,9 @@ cfg_if! {
         // this run-time detection logic is never called.
         #[path = "os/other.rs"]
         mod os;
+    } else if #[cfg(rust_compiler="mrustc")] {
+        #[path = "os/other.rs"]
+        mod os;
     } else if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
         // On x86/x86_64 no OS specific functionality is required.
         #[path = "os/x86.rs"]

--- vendor/ppv-lite86/src/lib.rs
+++ vendor/ppv-lite86/src/lib.rs
@@ -9,14 +9,14 @@ mod soft;
 mod types;
 pub use self::types::*;
 
-#[cfg(all(feature = "simd", target_arch = "x86_64", not(miri)))]
+#[cfg(all(feature = "simd", target_arch = "x86_64", not(miri), not(rust_compiler="mrustc")))]
 pub mod x86_64;
-#[cfg(all(feature = "simd", target_arch = "x86_64", not(miri)))]
+#[cfg(all(feature = "simd", target_arch = "x86_64", not(miri), not(rust_compiler="mrustc")))]
 use self::x86_64 as arch;
 
-#[cfg(any(miri, not(all(feature = "simd", any(target_arch = "x86_64")))))]
+#[cfg(any(miri, rust_compiler="mrustc", not(all(feature = "simd", any(target_arch = "x86_64")))))]
 pub mod generic;
-#[cfg(any(miri, not(all(feature = "simd", any(target_arch = "x86_64")))))]
+#[cfg(any(miri, rust_compiler="mrustc", not(all(feature = "simd", any(target_arch = "x86_64")))))]
 use self::generic as arch;
 
 pub use self::arch::{vec128_storage, vec256_storage, vec512_storage};