1 files changed, 52 insertions, 5 deletions

diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 91283a5944e..79381f35a3c 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -1,11 +1,13 @@
 use std::borrow::Borrow;
 use std::cell::{Cell, RefCell};
 use std::ffi::{CStr, c_char, c_uint};
+use std::ops::Deref;
 use std::str;
 
 use rustc_abi::{HasDataLayout, TargetDataLayout, VariantIdx};
 use rustc_codegen_ssa::back::versioned_llvm_target;
 use rustc_codegen_ssa::base::{wants_msvc_seh, wants_wasm_eh};
+use rustc_codegen_ssa::common::TypeKind;
 use rustc_codegen_ssa::errors as ssa_errors;
 use rustc_codegen_ssa::traits::*;
 use rustc_data_structures::base_n::{ALPHANUMERIC_ONLY, ToBaseN};
@@ -30,23 +32,46 @@ use smallvec::SmallVec;
 
 use crate::back::write::to_llvm_code_model;
 use crate::callee::get_fn;
-use crate::common::AsCCharPtr;
+use crate::common::{self, AsCCharPtr};
 use crate::debuginfo::metadata::apply_vcall_visibility_metadata;
 use crate::llvm::{Metadata, MetadataType};
 use crate::type_::Type;
 use crate::value::Value;
 use crate::{attributes, coverageinfo, debuginfo, llvm, llvm_util};
 
+/// `TyCtxt` (and related cache datastructures) can't be move between threads.
+/// However, there are various cx related functions which we want to be available to the builder and
+/// other compiler pieces. Here we define a small subset which has enough information and can be
+/// moved around more freely.
+pub(crate) struct SimpleCx<'ll> {
+    pub llmod: &'ll llvm::Module,
+    pub llcx: &'ll llvm::Context,
+}
+
+impl<'ll> Borrow<SimpleCx<'ll>> for CodegenCx<'ll, '_> {
+    fn borrow(&self) -> &SimpleCx<'ll> {
+        &self.scx
+    }
+}
+
+impl<'ll, 'tcx> Deref for CodegenCx<'ll, 'tcx> {
+    type Target = SimpleCx<'ll>;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        &self.scx
+    }
+}
+
 /// There is one `CodegenCx` per codegen unit. Each one has its own LLVM
 /// `llvm::Context` so that several codegen units may be processed in parallel.
 /// All other LLVM data structures in the `CodegenCx` are tied to that `llvm::Context`.
 pub(crate) struct CodegenCx<'ll, 'tcx> {
     pub tcx: TyCtxt<'tcx>,
+    pub scx: SimpleCx<'ll>,
     pub use_dll_storage_attrs: bool,
     pub tls_model: llvm::ThreadLocalMode,
 
-    pub llmod: &'ll llvm::Module,
-    pub llcx: &'ll llvm::Context,
     pub codegen_unit: &'tcx CodegenUnit<'tcx>,
 
     /// Cache instances of monomorphic and polymorphic items
@@ -553,10 +578,9 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
 
         CodegenCx {
             tcx,
+            scx: SimpleCx { llcx, llmod },
             use_dll_storage_attrs,
             tls_model,
-            llmod,
-            llcx,
             codegen_unit,
             instances: Default::default(),
             vtables: Default::default(),
@@ -600,6 +624,11 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
             llvm::set_section(g, c"llvm.metadata");
         }
     }
+}
+impl<'ll> SimpleCx<'ll> {
+    pub(crate) fn val_ty(&self, v: &'ll Value) -> &'ll Type {
+        common::val_ty(v)
+    }
 
     pub(crate) fn get_metadata_value(&self, metadata: &'ll Metadata) -> &'ll Value {
         unsafe { llvm::LLVMMetadataAsValue(self.llcx, metadata) }
@@ -625,6 +654,10 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
             llvm::LLVMMDStringInContext2(self.llcx, name.as_ptr() as *const c_char, name.len())
         })
     }
+
+    pub(crate) fn type_kind(&self, ty: &'ll Type) -> TypeKind {
+        unsafe { llvm::LLVMRustGetTypeKind(ty).to_generic() }
+    }
 }
 
 impl<'ll, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
@@ -1178,6 +1211,20 @@ impl CodegenCx<'_, '_> {
     }
 }
 
+// This is a duplication of the set_metadata function above. However, so far it's the only one
+// shared between both contexts, so it doesn't seem worth it to make the Cx generic like we did it
+// for the Builder.
+impl SimpleCx<'_> {
+    #[allow(unused)]
+    /// A wrapper for [`llvm::LLVMSetMetadata`], but it takes `Metadata` as a parameter instead of `Value`.
+    pub(crate) fn set_metadata<'a>(&self, val: &'a Value, kind_id: MetadataType, md: &'a Metadata) {
+        unsafe {
+            let node = llvm::LLVMMetadataAsValue(&self.llcx, md);
+            llvm::LLVMSetMetadata(val, kind_id as c_uint, node);
+        }
+    }
+}
+
 impl HasDataLayout for CodegenCx<'_, '_> {
     #[inline]
     fn data_layout(&self) -> &TargetDataLayout {