Auto merge of #136318 - matthiaskrgr:rollup-a159mzo, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #135026 (Cast global variables to default address space)
 - #135475 (uefi: Implement path)
 - #135852 (Add `AsyncFn*` to `core` prelude)
 - #136004 (tests: Skip const OOM tests on aarch64-unknown-linux-gnu)
 - #136157 (override build profile for bootstrap tests)
 - #136180 (Introduce a wrapper for "typed valtrees" and properly check the type before extracting the value)
 - #136256 (Add release notes for 1.84.1)
 - #136271 (Remove minor future footgun in `impl Debug for MaybeUninit`)
 - #136288 (Improve documentation for file locking)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 25 insertions, 0 deletions

diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index 2a1a12f3ce5..6eae16d8be6 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -1487,6 +1487,26 @@ fn build_vtable_type_di_node<'ll, 'tcx>(
     .di_node
 }
 
+/// Get the global variable for the vtable.
+///
+/// When using global variables, we may have created an addrspacecast to get a pointer to the
+/// default address space if global variables are created in a different address space.
+/// For modifying the vtable, we need the real global variable. This function accepts either a
+/// global variable (which is simply returned), or an addrspacecast constant expression.
+/// If the given value is an addrspacecast, the cast is removed and the global variable behind
+/// the cast is returned.
+fn find_vtable_behind_cast<'ll>(vtable: &'ll Value) -> &'ll Value {
+    // The vtable is a global variable, which may be behind an addrspacecast.
+    unsafe {
+        if let Some(c) = llvm::LLVMIsAConstantExpr(vtable) {
+            if llvm::LLVMGetConstOpcode(c) == llvm::Opcode::AddrSpaceCast {
+                return llvm::LLVMGetOperand(c, 0).unwrap();
+            }
+        }
+    }
+    vtable
+}
+
 pub(crate) fn apply_vcall_visibility_metadata<'ll, 'tcx>(
     cx: &CodegenCx<'ll, 'tcx>,
     ty: Ty<'tcx>,
@@ -1507,6 +1527,8 @@ pub(crate) fn apply_vcall_visibility_metadata<'ll, 'tcx>(
 
     let Some(trait_ref) = trait_ref else { return };
 
+    // Unwrap potential addrspacecast
+    let vtable = find_vtable_behind_cast(vtable);
     let trait_ref_self = trait_ref.with_self_ty(cx.tcx, ty);
     let trait_ref_self = cx.tcx.erase_regions(trait_ref_self);
     let trait_def_id = trait_ref_self.def_id();
@@ -1580,6 +1602,9 @@ pub(crate) fn create_vtable_di_node<'ll, 'tcx>(
         return;
     }
 
+    // Unwrap potential addrspacecast
+    let vtable = find_vtable_behind_cast(vtable);
+
     // When full debuginfo is enabled, we want to try and prevent vtables from being
     // merged. Otherwise debuggers will have a hard time mapping from dyn pointer
     // to concrete type.