[Protocol Metadata] Create protocol metadata using WeakAnyLinkage to avoid duplication

Author: alx32

lib/IRGen/GenClass.cpp

@@ -1766,8 +1766,12 @@ namespace {
         return null();
       }
 
-      return buildGlobalVariable(array, "_PROTOCOL_METHOD_TYPES_",
-                                 /*const*/ true);
+      auto *gv_as_const =  buildGlobalVariable(array, "_PROTOCOL_METHOD_TYPES_",
+                               /*const*/ true,
+                               /*likage*/ llvm::GlobalVariable::WeakAnyLinkage);
+      llvm::GlobalValue *gv = (llvm::GlobalValue *)gv_as_const;
+      gv->setVisibility(llvm::GlobalValue::HiddenVisibility);
+      return gv;
     }
 
     void buildExtMethodTypes(ConstantArrayBuilder &array,
@@ -2167,8 +2171,9 @@ namespace {
     /// Build a private global variable as a structure containing the
     /// given fields.
     template <class B>
-    llvm::Constant *buildGlobalVariable(B &fields, StringRef nameBase,
-                                        bool isConst) {
+    llvm::Constant *buildGlobalVariable(B &fields, StringRef nameBase, bool isConst,
+                      llvm::GlobalValue::LinkageTypes linkage =
+                          llvm::GlobalVariable::InternalLinkage) {
       llvm::SmallString<64> nameBuffer;
       auto var =
         fields.finishAndCreateGlobal(Twine(nameBase) 
@@ -2178,7 +2183,7 @@ namespace {
                                            : Twine()),
                                      IGM.getPointerAlignment(),
                                      /*constant*/ true,
-                                     llvm::GlobalVariable::InternalLinkage);
+                                     linkage);
 
       switch (IGM.TargetInfo.OutputObjectFormat) {
       case llvm::Triple::MachO:

test/IRGen/objc_async_metadata.swift

@@ -28,7 +28,7 @@ class MyClass: NSObject {
 // CHECK-SAME: [15 x i8]* [[ENCODE_ASYNC_STRING_PROTO]]
 
 // CHECK: [[ENCODE_ASYNC_STRING_PROTO_TYPE:@.*]] = private unnamed_addr constant [41 x i8] c"v32@0:8@\22NSString\2216@?<v@?@\22NSString\22>24\00"
-// CHECK-LABEL: @_PROTOCOL_METHOD_TYPES__TtP19objc_async_metadata7MyProto_ = internal constant
+// CHECK-LABEL: @_PROTOCOL_METHOD_TYPES__TtP19objc_async_metadata7MyProto_ = weak hidden constant
 // CHECK-SAME: [41 x i8]* [[ENCODE_ASYNC_STRING_PROTO_TYPE]]
 
 @objc protocol MyProto {

test/IRGen/objc_methods.swift

@@ -99,7 +99,7 @@ class ObjcDestructible: NSObject {
 // CHECK: [[ARRAY_SIGNATURE_EXT:@.*]] = private unnamed_addr constant [29 x i8] c"@\22NSArray\2224@0:8@\22NSArray\2216\00"
 // CHECK: [[DICT_SIGNATURE_EXT:@.*]] = private unnamed_addr constant [39 x i8] c"@\22NSDictionary\2224@0:8@\22NSDictionary\2216\00"
 // CHECK: [[SET_SIGNATURE_EXT:@.*]] = private unnamed_addr constant [25 x i8] c"@\22NSSet\2224@0:8@\22NSSet\2216\00"
-// CHECK: @_PROTOCOL_METHOD_TYPES__TtP12objc_methods7Fooable_ = internal constant [6 x i8*] [
+// CHECK: @_PROTOCOL_METHOD_TYPES__TtP12objc_methods7Fooable_ = weak hidden constant [6 x i8*] [
 // CHECK:     i8* getelementptr inbounds ([18 x i8], [18 x i8]* [[BLOCK_SIGNATURE_EXT_1]], i64 0, i64 0)
 // CHECK:     i8* getelementptr inbounds ([19 x i8], [19 x i8]* [[BLOCK_SIGNATURE_EXT_2]], i64 0, i64 0)
 // CHECK:     i8* getelementptr inbounds ([31 x i8], [31 x i8]* [[STRING_SIGNATURE_EXT]], i64 0, i64 0)

test/IRGen/objc_protocol_extended_method_types.swift

@@ -29,7 +29,7 @@ import Foundation
 // CHECK-JIT-DAG: [[TY_ID:@.*]] = private unnamed_addr constant [8 x i8] c"@16@0:8\00"
 // CHECK-JIT-DAG: [[TY_INT_INT:@.*]] = private unnamed_addr constant [11 x i8] c"q24@0:8q16\00"
 
-// CHECK-LABEL: @_PROTOCOL_METHOD_TYPES__TtP35objc_protocol_extended_method_types1P_ = internal constant [16 x i8*] [
+// CHECK-LABEL: @_PROTOCOL_METHOD_TYPES__TtP35objc_protocol_extended_method_types1P_ = weak hidden constant [16 x i8*] [
 // -- required instance methods:
 //   -- requiredInstanceMethod
 // CHECK:         i8* getelementptr inbounds ([31 x i8], [31 x i8]* [[NSNUMBER]], i64 0, i64 0),

test/IRGen/objc_type_encoding.swift

@@ -199,22 +199,22 @@ import gizmo
 // CHECK-macosx: [[ENC2:@.*]] = private unnamed_addr constant [46 x i8] c"v32@0:8@\22Gizmo\2216@?<v@?@\22NSView\22@\22NSSpoon\22>24\00"
 // CHECK-macosx: [[ENC3:@.*]] = private unnamed_addr constant [53 x i8] c"v24@0:8@\22_TtC18objc_type_encoding14MyCustomObject\2216\00"
 // CHECK-macosx: [[ENC4:@.*]] = private unnamed_addr constant [75 x i8] c"v24@0:8@\22_TtC18objc_type_encoding14MyCustomObject<NSFunging><NSRuncing>\2216\00"
-// CHECK-macosx: @_PROTOCOL_METHOD_TYPES__TtP18objc_type_encoding10MyProtocol_ = internal constant [4 x i8*] [i8* getelementptr inbounds ([35 x i8], [35 x i8]* [[ENC1]], i64 0, i64 0), i8* getelementptr inbounds ([46 x i8], [46 x i8]* [[ENC2]], i64 0, i64 0), i8* getelementptr inbounds ([53 x i8], [53 x i8]* [[ENC3]], i64 0, i64 0), i8* getelementptr inbounds ([75 x i8], [75 x i8]* [[ENC4]], i64 0, i64 0)]
+// CHECK-macosx: @_PROTOCOL_METHOD_TYPES__TtP18objc_type_encoding10MyProtocol_ = weak hidden constant [4 x i8*] [i8* getelementptr inbounds ([35 x i8], [35 x i8]* [[ENC1]], i64 0, i64 0), i8* getelementptr inbounds ([46 x i8], [46 x i8]* [[ENC2]], i64 0, i64 0), i8* getelementptr inbounds ([53 x i8], [53 x i8]* [[ENC3]], i64 0, i64 0), i8* getelementptr inbounds ([75 x i8], [75 x i8]* [[ENC4]], i64 0, i64 0)]
 // CHECK-ios: [[ENC1:@.*]] = private unnamed_addr constant [35 x i8] c"v24@0:8@\22<NSFunging><NSRuncing>\2216\00"
 // CHECK-ios: [[ENC2:@.*]] = private unnamed_addr constant [46 x i8] c"v32@0:8@\22Gizmo\2216@?<v@?@\22NSView\22@\22NSSpoon\22>24\00"
 // CHECK-ios: [[ENC3:@.*]] = private unnamed_addr constant [53 x i8] c"v24@0:8@\22_TtC18objc_type_encoding14MyCustomObject\2216\00"
 // CHECK-ios: [[ENC4:@.*]] = private unnamed_addr constant [75 x i8] c"v24@0:8@\22_TtC18objc_type_encoding14MyCustomObject<NSFunging><NSRuncing>\2216\00"
-// CHECK-ios: @_PROTOCOL_METHOD_TYPES__TtP18objc_type_encoding10MyProtocol_ = internal constant [4 x i8*] [i8* getelementptr inbounds ([35 x i8], [35 x i8]* [[ENC1]], i64 0, i64 0), i8* getelementptr inbounds ([46 x i8], [46 x i8]* [[ENC2]], i64 0, i64 0), i8* getelementptr inbounds ([53 x i8], [53 x i8]* [[ENC3]], i64 0, i64 0), i8* getelementptr inbounds ([75 x i8], [75 x i8]* [[ENC4]], i64 0, i64 0)]
+// CHECK-ios: @_PROTOCOL_METHOD_TYPES__TtP18objc_type_encoding10MyProtocol_ = weak hidden constant [4 x i8*] [i8* getelementptr inbounds ([35 x i8], [35 x i8]* [[ENC1]], i64 0, i64 0), i8* getelementptr inbounds ([46 x i8], [46 x i8]* [[ENC2]], i64 0, i64 0), i8* getelementptr inbounds ([53 x i8], [53 x i8]* [[ENC3]], i64 0, i64 0), i8* getelementptr inbounds ([75 x i8], [75 x i8]* [[ENC4]], i64 0, i64 0)]
 // CHECK-tvos: [[ENC1:@.*]] = private unnamed_addr constant [35 x i8] c"v24@0:8@\22<NSFunging><NSRuncing>\2216\00"
 // CHECK-tvos: [[ENC2:@.*]] = private unnamed_addr constant [46 x i8] c"v32@0:8@\22Gizmo\2216@?<v@?@\22NSView\22@\22NSSpoon\22>24\00"
 // CHECK-tvos: [[ENC3:@.*]] = private unnamed_addr constant [53 x i8] c"v24@0:8@\22_TtC18objc_type_encoding14MyCustomObject\2216\00"
 // CHECK-tvos: [[ENC4:@.*]] = private unnamed_addr constant [75 x i8] c"v24@0:8@\22_TtC18objc_type_encoding14MyCustomObject<NSFunging><NSRuncing>\2216\00"
-// CHECK-tvos: @_PROTOCOL_METHOD_TYPES__TtP18objc_type_encoding10MyProtocol_ = internal constant [4 x i8*] [i8* getelementptr inbounds ([35 x i8], [35 x i8]* [[ENC1]], i64 0, i64 0), i8* getelementptr inbounds ([46 x i8], [46 x i8]* [[ENC2]], i64 0, i64 0), i8* getelementptr inbounds ([53 x i8], [53 x i8]* [[ENC3]], i64 0, i64 0), i8* getelementptr inbounds ([75 x i8], [75 x i8]* [[ENC4]], i64 0, i64 0)]
+// CHECK-tvos: @_PROTOCOL_METHOD_TYPES__TtP18objc_type_encoding10MyProtocol_ = weak hidden constant [4 x i8*] [i8* getelementptr inbounds ([35 x i8], [35 x i8]* [[ENC1]], i64 0, i64 0), i8* getelementptr inbounds ([46 x i8], [46 x i8]* [[ENC2]], i64 0, i64 0), i8* getelementptr inbounds ([53 x i8], [53 x i8]* [[ENC3]], i64 0, i64 0), i8* getelementptr inbounds ([75 x i8], [75 x i8]* [[ENC4]], i64 0, i64 0)]
 // CHECK-watchos: [[ENC1:@.*]] = private unnamed_addr constant [35 x i8] c"v24@0:8@\22<NSFunging><NSRuncing>\2216\00"
 // CHECK-watchos: [[ENC2:@.*]] = private unnamed_addr constant [46 x i8] c"v32@0:8@\22Gizmo\2216@?<v@?@\22NSView\22@\22NSSpoon\22>24\00"
 // CHECK-watchos: [[ENC3:@.*]] = private unnamed_addr constant [53 x i8] c"v24@0:8@\22_TtC18objc_type_encoding14MyCustomObject\2216\00"
 // CHECK-watchos: [[ENC4:@.*]] = private unnamed_addr constant [75 x i8] c"v24@0:8@\22_TtC18objc_type_encoding14MyCustomObject<NSFunging><NSRuncing>\2216\00"
-// CHECK-watchos: @_PROTOCOL_METHOD_TYPES__TtP18objc_type_encoding10MyProtocol_ = internal constant [4 x i8*] [i8* getelementptr inbounds ([35 x i8], [35 x i8]* [[ENC1]], i64 0, i64 0), i8* getelementptr inbounds ([46 x i8], [46 x i8]* [[ENC2]], i64 0, i64 0), i8* getelementptr inbounds ([53 x i8], [53 x i8]* [[ENC3]], i64 0, i64 0), i8* getelementptr inbounds ([75 x i8], [75 x i8]* [[ENC4]], i64 0, i64 0)]
+// CHECK-watchos: @_PROTOCOL_METHOD_TYPES__TtP18objc_type_encoding10MyProtocol_ = weak hidden constant [4 x i8*] [i8* getelementptr inbounds ([35 x i8], [35 x i8]* [[ENC1]], i64 0, i64 0), i8* getelementptr inbounds ([46 x i8], [46 x i8]* [[ENC2]], i64 0, i64 0), i8* getelementptr inbounds ([53 x i8], [53 x i8]* [[ENC3]], i64 0, i64 0), i8* getelementptr inbounds ([75 x i8], [75 x i8]* [[ENC4]], i64 0, i64 0)]
 
 class C: P {
   func stuff() {}