2 files changed, 18 insertions, 17 deletions
diff --git a/compiler/rustc_codegen_llvm/src/callee.rs b/compiler/rustc_codegen_llvm/src/callee.rs
index 949fd1bc124..db4e1bae942 100644
--- a/compiler/rustc_codegen_llvm/src/callee.rs
+++ b/compiler/rustc_codegen_llvm/src/callee.rs
@@ -49,6 +49,22 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
         let llfn = if tcx.sess.target.arch == "x86"
             && let Some(dllimport) = crate::common::get_dllimport(tcx, instance_def_id, sym)
         {
+            // When calling functions in generated import libraries, MSVC needs
+            // the fully decorated name (as would have been in the declaring
+            // object file), but MinGW wants the name as exported (as would be
+            // in the def file) which may be missing decorations.
+            let mingw_gnu_toolchain = common::is_mingw_gnu_toolchain(&tcx.sess.target);
+            let llfn = cx.declare_fn(
+                &common::i686_decorated_name(
+                    dllimport,
+                    mingw_gnu_toolchain,
+                    true,
+                    !mingw_gnu_toolchain,
+                ),
+                fn_abi,
+                Some(instance),
+            );
+
             // Fix for https://github.com/rust-lang/rust/issues/104453
             // On x86 Windows, LLVM uses 'L' as the prefix for any private
             // global symbols, so when we create an undecorated function symbol
@@ -60,15 +76,6 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
             // LLVM will prefix the name with `__imp_`. Ideally, we'd like the
             // existing logic below to set the Storage Class, but it has an
             // exemption for MinGW for backwards compatibility.
-            let llfn = cx.declare_fn(
-                &common::i686_decorated_name(
-                    dllimport,
-                    common::is_mingw_gnu_toolchain(&tcx.sess.target),
-                    true,
-                ),
-                fn_abi,
-                Some(instance),
-            );
             unsafe {
                 llvm::LLVMSetDLLStorageClass(llfn, llvm::DLLStorageClass::DllImport);
             }
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs
index c3b1676f77e..dc86ef22e37 100644
--- a/compiler/rustc_codegen_llvm/src/consts.rs
+++ b/compiler/rustc_codegen_llvm/src/consts.rs
@@ -196,16 +196,10 @@ fn check_and_apply_linkage<'ll, 'tcx>(
             g2
         }
     } else if cx.tcx.sess.target.arch == "x86"
+        && common::is_mingw_gnu_toolchain(&cx.tcx.sess.target)
         && let Some(dllimport) = crate::common::get_dllimport(cx.tcx, def_id, sym)
     {
-        cx.declare_global(
-            &common::i686_decorated_name(
-                dllimport,
-                common::is_mingw_gnu_toolchain(&cx.tcx.sess.target),
-                true,
-            ),
-            llty,
-        )
+        cx.declare_global(&common::i686_decorated_name(dllimport, true, true, false), llty)
     } else {
         // Generate an external declaration.
         // FIXME(nagisa): investigate whether it can be changed into define_global