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.

1 files changed, 4 insertions, 3 deletions

diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 5675a5d9812..0e2c4ddc2a3 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -497,9 +497,10 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             OperandValue::Immediate(self.to_immediate(llval, place.layout))
         } else if let abi::Abi::ScalarPair(ref a, ref b) = place.layout.abi {
             let b_offset = a.value.size(self).align_to(b.value.align(self).abi);
+            let pair_ty = place.layout.llvm_type(self);
 
             let mut load = |i, scalar: &abi::Scalar, align| {
-                let llptr = self.struct_gep(place.llval, i as u64);
+                let llptr = self.struct_gep(pair_ty, place.llval, i as u64);
                 let llty = place.layout.scalar_pair_element_llvm_type(self, i, false);
                 let load = self.load(llty, llptr, align);
                 scalar_load_metadata(self, load, scalar);
@@ -663,9 +664,9 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         }
     }
 
-    fn struct_gep(&mut self, ptr: &'ll Value, idx: u64) -> &'ll Value {
+    fn struct_gep(&mut self, ty: &'ll Type, ptr: &'ll Value, idx: u64) -> &'ll Value {
         assert_eq!(idx as c_uint as u64, idx);
-        unsafe { llvm::LLVMBuildStructGEP(self.llbuilder, ptr, idx as c_uint, UNNAMED) }
+        unsafe { llvm::LLVMBuildStructGEP2(self.llbuilder, ty, ptr, idx as c_uint, UNNAMED) }
     }
 
     /* Casts */