8 files changed, 34 insertions, 13 deletions
diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs
index be539499b56..3731c6bcfe7 100644
--- a/compiler/rustc_codegen_llvm/src/back/lto.rs
+++ b/compiler/rustc_codegen_llvm/src/back/lto.rs
@@ -199,7 +199,7 @@ pub(crate) fn run_thin(
 
 pub(crate) fn prepare_thin(module: ModuleCodegen<ModuleLlvm>) -> (String, ThinBuffer) {
     let name = module.name.clone();
-    let buffer = ThinBuffer::new(module.module_llvm.llmod());
+    let buffer = ThinBuffer::new(module.module_llvm.llmod(), true);
     (name, buffer)
 }
 
@@ -695,9 +695,9 @@ unsafe impl Send for ThinBuffer {}
 unsafe impl Sync for ThinBuffer {}
 
 impl ThinBuffer {
-    pub fn new(m: &llvm::Module) -> ThinBuffer {
+    pub fn new(m: &llvm::Module, is_thin: bool) -> ThinBuffer {
         unsafe {
-            let buffer = llvm::LLVMRustThinLTOBufferCreate(m);
+            let buffer = llvm::LLVMRustThinLTOBufferCreate(m, is_thin);
             ThinBuffer(buffer)
         }
     }
diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index 2b465ce40e7..534d32e8a90 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -790,7 +790,7 @@ pub(crate) unsafe fn codegen(
             let _timer = cgcx
                 .prof
                 .generic_activity_with_arg("LLVM_module_codegen_make_bitcode", &*module.name);
-            let thin = ThinBuffer::new(llmod);
+            let thin = ThinBuffer::new(llmod, config.emit_thin_lto);
             let data = thin.data();
 
             if let Some(bitcode_filename) = bc_out.file_name() {
diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs
index 77cbbf4c6ca..fb4da9a5f33 100644
--- a/compiler/rustc_codegen_llvm/src/common.rs
+++ b/compiler/rustc_codegen_llvm/src/common.rs
@@ -257,6 +257,15 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                         self.get_fn_addr(fn_instance.polymorphize(self.tcx)),
                         self.data_layout().instruction_address_space,
                     ),
+                    GlobalAlloc::VTable(ty, trait_ref) => {
+                        let alloc = self
+                            .tcx
+                            .global_alloc(self.tcx.vtable_allocation((ty, trait_ref)))
+                            .unwrap_memory();
+                        let init = const_alloc_to_llvm(self, alloc);
+                        let value = self.static_addr_of(init, alloc.inner().align, None);
+                        (value, AddressSpace::DATA)
+                    }
                     GlobalAlloc::Static(def_id) => {
                         assert!(self.tcx.is_static(def_id));
                         assert!(!self.tcx.is_thread_local_static(def_id));
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs
index 2b16ae1a88d..18467e37082 100644
--- a/compiler/rustc_codegen_llvm/src/consts.rs
+++ b/compiler/rustc_codegen_llvm/src/consts.rs
@@ -101,7 +101,9 @@ pub fn const_alloc_to_llvm<'ll>(cx: &CodegenCx<'ll, '_>, alloc: ConstAllocation<
 
         let address_space = match cx.tcx.global_alloc(alloc_id) {
             GlobalAlloc::Function(..) => cx.data_layout().instruction_address_space,
-            GlobalAlloc::Static(..) | GlobalAlloc::Memory(..) => AddressSpace::DATA,
+            GlobalAlloc::Static(..) | GlobalAlloc::Memory(..) | GlobalAlloc::VTable(..) => {
+                AddressSpace::DATA
+            }
         };
 
         llvals.push(cx.scalar_to_backend(
@@ -535,10 +537,20 @@ impl<'ll> StaticMethods for CodegenCx<'ll, '_> {
 
                 // The semantics of #[used] in Rust only require the symbol to make it into the
                 // object file. It is explicitly allowed for the linker to strip the symbol if it
-                // is dead. As such, use llvm.compiler.used instead of llvm.used.
+                // is dead, which means we are allowed use `llvm.compiler.used` instead of
+                // `llvm.used` here.
+                //
                 // Additionally, https://reviews.llvm.org/D97448 in LLVM 13 started emitting unique
                 // sections with SHF_GNU_RETAIN flag for llvm.used symbols, which may trigger bugs
-                // in some versions of the gold linker.
+                // in the handling of `.init_array` (the static constructor list) in versions of
+                // the gold linker (prior to the one released with binutils 2.36).
+                //
+                // That said, we only ever emit these when compiling for ELF targets, unless
+                // `#[used(compiler)]` is explicitly requested. This is to avoid similar breakage
+                // on other targets, in particular MachO targets have *their* static constructor
+                // lists broken if `llvm.compiler.used` is emitted rather than llvm.used. However,
+                // that check happens when assigning the `CodegenFnAttrFlags` in `rustc_typeck`,
+                // so we don't need to take care of it here.
                 self.add_compiler_used_global(g);
             }
             if attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER) {
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs
index 5186aee57fb..80fd9726fc7 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs
@@ -55,7 +55,7 @@ pub fn get_or_insert_gdb_debug_scripts_section_global<'ll>(cx: &CodegenCx<'ll, '
             // The initial byte `4` instructs GDB that the following pretty printer
             // is defined inline as opposed to in a standalone file.
             section_contents.extend_from_slice(b"\x04");
-            let vis_name = format!("pretty-printer-{}-{}\n", crate_name.as_str(), index);
+            let vis_name = format!("pretty-printer-{}-{}\n", crate_name, index);
             section_contents.extend_from_slice(vis_name.as_bytes());
             section_contents.extend_from_slice(&visualizer.src);
 
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index f8bd2d234f3..bd84100e0e8 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -1420,7 +1420,7 @@ fn build_vtable_type_di_node<'ll, 'tcx>(
         cx,
         type_map::stub(
             cx,
-            Stub::VtableTy { vtable_holder },
+            Stub::VTableTy { vtable_holder },
             unique_type_id,
             &vtable_type_name,
             (size, pointer_align),
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs
index 8fc8118849b..ce2f419c4ac 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs
@@ -146,7 +146,7 @@ impl<'ll> DINodeCreationResult<'ll> {
 pub enum Stub<'ll> {
     Struct,
     Union,
-    VtableTy { vtable_holder: &'ll DIType },
+    VTableTy { vtable_holder: &'ll DIType },
 }
 
 pub struct StubInfo<'ll, 'tcx> {
@@ -180,9 +180,9 @@ pub(super) fn stub<'ll, 'tcx>(
     let unique_type_id_str = unique_type_id.generate_unique_id_string(cx.tcx);
 
     let metadata = match kind {
-        Stub::Struct | Stub::VtableTy { .. } => {
+        Stub::Struct | Stub::VTableTy { .. } => {
             let vtable_holder = match kind {
-                Stub::VtableTy { vtable_holder } => Some(vtable_holder),
+                Stub::VTableTy { vtable_holder } => Some(vtable_holder),
                 _ => None,
             };
             unsafe {
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 73cedb59349..624ce8d9369 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -2470,7 +2470,7 @@ extern "C" {
     pub fn LLVMRustModuleBufferFree(p: &'static mut ModuleBuffer);
     pub fn LLVMRustModuleCost(M: &Module) -> u64;
 
-    pub fn LLVMRustThinLTOBufferCreate(M: &Module) -> &'static mut ThinLTOBuffer;
+    pub fn LLVMRustThinLTOBufferCreate(M: &Module, is_thin: bool) -> &'static mut ThinLTOBuffer;
     pub fn LLVMRustThinLTOBufferFree(M: &'static mut ThinLTOBuffer);
     pub fn LLVMRustThinLTOBufferPtr(M: &ThinLTOBuffer) -> *const c_char;
     pub fn LLVMRustThinLTOBufferLen(M: &ThinLTOBuffer) -> size_t;