add externally_initialized to OBJC_SELECTOR_REFERENCES_

Author: jbatez

compiler/rustc_codegen_llvm/src/consts.rs

@@ -680,6 +680,7 @@ impl<'ll> CodegenCx<'ll, '_> {
         });
         set_global_alignment(self, selref_g, self.tcx.data_layout.pointer_align().abi);
         llvm::set_initializer(selref_g, selref_llval);
+        llvm::set_externally_initialized(selref_g, true);
         if is_x86_32_macos {
             llvm::set_linkage(selref_g, llvm::Linkage::PrivateLinkage);
             llvm::set_section(selref_g, c"__OBJC,__message_refs,literal_pointers,no_dead_strip");

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -1189,6 +1189,7 @@ unsafe extern "C" {
     pub(crate) safe fn LLVMSetGlobalConstant(GlobalVar: &Value, IsConstant: Bool);
     pub(crate) safe fn LLVMSetTailCall(CallInst: &Value, IsTailCall: Bool);
     pub(crate) safe fn LLVMSetTailCallKind(CallInst: &Value, kind: TailCallKind);
+    pub(crate) safe fn LLVMSetExternallyInitialized(GlobalVar: &Value, IsExtInit: Bool);
 
     // Operations on attributes
     pub(crate) fn LLVMCreateStringAttribute(

compiler/rustc_codegen_llvm/src/llvm/mod.rs

@@ -248,6 +248,10 @@ pub(crate) fn set_alignment(llglobal: &Value, align: Align) {
     }
 }
 
+pub(crate) fn set_externally_initialized(llglobal: &Value, is_ext_init: bool) {
+    LLVMSetExternallyInitialized(llglobal, if is_ext_init { ffi::True } else { ffi::False });
+}
+
 /// Get the `name`d comdat from `llmod` and assign it to `llglobal`.
 ///
 /// Inserts the comdat into `llmod` if it does not exist.

tests/codegen-llvm/darwin-objc-32bit-x86-macos.rs

@@ -35,7 +35,7 @@ pub fn get_selector() -> *mut () {
 // CHECK: @OBJC_CLASS_REFERENCES_.{{[0-9]+}} = private global ptr @OBJC_CLASS_NAME_.{{[0-9]+}}, section "__OBJC,__cls_refs,literal_pointers,no_dead_strip", align 4
 
 // CHECK: @OBJC_METH_VAR_NAME_.{{[0-9]+}} = private unnamed_addr constant [9 x i8] c"myMethod\00", section "__TEXT,__cstring,cstring_literals", align 1
-// CHECK: @OBJC_SELECTOR_REFERENCES_.{{[0-9]+}} = private global ptr @OBJC_METH_VAR_NAME_.{{[0-9]+}}, section "__OBJC,__message_refs,literal_pointers,no_dead_strip", align 4
+// CHECK: @OBJC_SELECTOR_REFERENCES_.{{[0-9]+}} = private externally_initialized global ptr @OBJC_METH_VAR_NAME_.{{[0-9]+}}, section "__OBJC,__message_refs,literal_pointers,no_dead_strip", align 4
 
 // CHECK: @OBJC_CLASS_NAME_.{{[0-9]+}} = private unnamed_addr constant [1 x i8] zeroinitializer, section "__TEXT,__cstring,cstring_literals", align 1
 // CHECK: @OBJC_MODULES = private global %struct._objc_module { i32 7, i32 16, ptr @OBJC_CLASS_NAME_.{{[0-9]+}}, ptr null }, section "__OBJC,__module_info,regular,no_dead_strip", align 4

tests/codegen-llvm/darwin-objc.rs

@@ -59,7 +59,7 @@ pub fn get_selector() -> *mut () {
 // aarch64_ios_sim-SAME: align 8
 
 // CHECK: @OBJC_METH_VAR_NAME_.{{[0-9]+}} = private unnamed_addr constant [9 x i8] c"myMethod\00", section "__TEXT,__objc_methname,cstring_literals", align 1
-// CHECK: @OBJC_SELECTOR_REFERENCES_.{{[0-9]+}} = internal global ptr @OBJC_METH_VAR_NAME_.{{[0-9]+}}, section "__DATA,__objc_selrefs,literal_pointers,no_dead_strip",
+// CHECK: @OBJC_SELECTOR_REFERENCES_.{{[0-9]+}} = internal externally_initialized global ptr @OBJC_METH_VAR_NAME_.{{[0-9]+}}, section "__DATA,__objc_selrefs,literal_pointers,no_dead_strip",
 // x86_64_macos-SAME: align 8
 // aarch64_macos-SAME: align 8
 // i386_ios-SAME: align 4