diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs index dd3c43ba5ca7c..bf5ac4e503e3f 100644 --- a/compiler/rustc_codegen_llvm/src/consts.rs +++ b/compiler/rustc_codegen_llvm/src/consts.rs @@ -19,6 +19,7 @@ use rustc_middle::mir::mono::MonoItem; use rustc_middle::ty::layout::LayoutOf; use rustc_middle::ty::{self, Instance, Ty}; use rustc_middle::{bug, span_bug}; +use rustc_session::config::Lto; use rustc_target::abi::{ AddressSpace, Align, HasDataLayout, Primitive, Scalar, Size, WrappingRange, }; @@ -303,7 +304,8 @@ impl<'ll> CodegenCx<'ll, '_> { // ThinLTO can't handle this workaround in all cases, so we don't // emit the attrs. Instead we make them unnecessary by disallowing // dynamic linking when linker plugin based LTO is enabled. - !self.tcx.sess.opts.cg.linker_plugin_lto.enabled(); + !self.tcx.sess.opts.cg.linker_plugin_lto.enabled() && + self.tcx.sess.lto() != Lto::Thin; // If this assertion triggers, there's something wrong with commandline // argument validation. diff --git a/src/test/codegen/auxiliary/static_dllimport_aux.rs b/src/test/codegen/auxiliary/static_dllimport_aux.rs new file mode 100644 index 0000000000000..afb0dc42f443a --- /dev/null +++ b/src/test/codegen/auxiliary/static_dllimport_aux.rs @@ -0,0 +1,13 @@ +use std::sync::atomic::{AtomicPtr, Ordering}; + +#[inline(always)] +pub fn memrchr() { + fn detect() {} + + static CROSS_CRATE_STATIC_ITEM: AtomicPtr<()> = AtomicPtr::new(detect as *mut ()); + + unsafe { + let fun = CROSS_CRATE_STATIC_ITEM.load(Ordering::SeqCst); + std::mem::transmute::<*mut (), fn()>(fun)() + } +} diff --git a/src/test/codegen/issue-81408-dllimport-thinlto-windows.rs b/src/test/codegen/issue-81408-dllimport-thinlto-windows.rs new file mode 100644 index 0000000000000..0b6ab4f7ecb3b --- /dev/null +++ b/src/test/codegen/issue-81408-dllimport-thinlto-windows.rs @@ -0,0 +1,15 @@ +// compile-flags: -O -C lto=thin -C prefer-dynamic=no +// only-windows +// aux-build:static_dllimport_aux.rs + +// Test that on Windows, when performing ThinLTO, we do not mark cross-crate static items with +// dllimport because lld does not fix the symbol names for us. + +extern crate static_dllimport_aux; + +// CHECK-LABEL: @{{.+}}CROSS_CRATE_STATIC_ITEM{{.+}} = +// CHECK-SAME: external local_unnamed_addr global %"{{.+}}AtomicPtr + +pub fn main() { + static_dllimport_aux::memrchr(); +}