Prepare struct_gep for opaque pointers

Imlement struct_gep using LLVMBuildStructGEP2 which takes an explicit
type argument instead of deriving it from a pointer type.

3 files changed, 10 insertions, 5 deletions

diff --git a/compiler/rustc_codegen_ssa/src/mir/operand.rs b/compiler/rustc_codegen_ssa/src/mir/operand.rs
index 3e8386bc88f..cfb2befdf91 100644
--- a/compiler/rustc_codegen_ssa/src/mir/operand.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/operand.rs
@@ -311,14 +311,15 @@ impl<'a, 'tcx, V: CodegenObject> OperandValue<V> {
                     Abi::ScalarPair(ref a, ref b) => (a, b),
                     _ => bug!("store_with_flags: invalid ScalarPair layout: {:#?}", dest.layout),
                 };
+                let ty = bx.backend_type(dest.layout);
                 let b_offset = a_scalar.value.size(bx).align_to(b_scalar.value.align(bx).abi);
 
-                let llptr = bx.struct_gep(dest.llval, 0);
+                let llptr = bx.struct_gep(ty, dest.llval, 0);
                 let val = bx.from_immediate(a);
                 let align = dest.align;
                 bx.store_with_flags(val, llptr, align, flags);
 
-                let llptr = bx.struct_gep(dest.llval, 1);
+                let llptr = bx.struct_gep(ty, dest.llval, 1);
                 let val = bx.from_immediate(b);
                 let align = dest.align.restrict_for_offset(b_offset);
                 bx.store_with_flags(val, llptr, align, flags);
diff --git a/compiler/rustc_codegen_ssa/src/mir/place.rs b/compiler/rustc_codegen_ssa/src/mir/place.rs
index 66d9d1a1e0c..b8940245400 100644
--- a/compiler/rustc_codegen_ssa/src/mir/place.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/place.rs
@@ -103,7 +103,8 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
                     if offset == a.value.size(bx.cx()).align_to(b.value.align(bx.cx()).abi) =>
                 {
                     // Offset matches second field.
-                    bx.struct_gep(self.llval, 1)
+                    let ty = bx.backend_type(self.layout);
+                    bx.struct_gep(ty, self.llval, 1)
                 }
                 Abi::Scalar(_) | Abi::ScalarPair(..) | Abi::Vector { .. } if field.is_zst() => {
                     // ZST fields are not included in Scalar, ScalarPair, and Vector layouts, so manually offset the pointer.
@@ -119,7 +120,10 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
                         self.layout
                     );
                 }
-                _ => bx.struct_gep(self.llval, bx.cx().backend_field_index(self.layout, ix)),
+                _ => {
+                    let ty = bx.backend_type(self.layout);
+                    bx.struct_gep(ty, self.llval, bx.cx().backend_field_index(self.layout, ix))
+                }
             };
             PlaceRef {
                 // HACK(eddyb): have to bitcast pointers until LLVM removes pointee types.
diff --git a/compiler/rustc_codegen_ssa/src/traits/builder.rs b/compiler/rustc_codegen_ssa/src/traits/builder.rs
index f0c232a97bc..6c3f52b1b19 100644
--- a/compiler/rustc_codegen_ssa/src/traits/builder.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/builder.rs
@@ -178,7 +178,7 @@ pub trait BuilderMethods<'a, 'tcx>:
 
     fn gep(&mut self, ptr: Self::Value, indices: &[Self::Value]) -> Self::Value;
     fn inbounds_gep(&mut self, ptr: Self::Value, indices: &[Self::Value]) -> Self::Value;
-    fn struct_gep(&mut self, ptr: Self::Value, idx: u64) -> Self::Value;
+    fn struct_gep(&mut self, ty: Self::Type, ptr: Self::Value, idx: u64) -> Self::Value;
 
     fn trunc(&mut self, val: Self::Value, dest_ty: Self::Type) -> Self::Value;
     fn sext(&mut self, val: Self::Value, dest_ty: Self::Type) -> Self::Value;