CodeGen: handle missed case of COMDAT handling

When Protocol references are constructed, we need to add the reference
symbol to a COMDAT group on non-MachO object file formats (MachO handles
this by having a coalesced attribute).  This adds the missing case.

llvm-svn: 306622

Author: compnerd

clang/lib/CodeGen/CGObjCMac.cpp

@@ -6381,16 +6381,15 @@ llvm::Value *CGObjCNonFragileABIMac::GenerateProtocolRef(CodeGenFunction &CGF,
   llvm::GlobalVariable *PTGV = CGM.getModule().getGlobalVariable(ProtocolName);
   if (PTGV)
     return CGF.Builder.CreateAlignedLoad(PTGV, Align);
-  PTGV = new llvm::GlobalVariable(
-    CGM.getModule(),
-    Init->getType(), false,
-    llvm::GlobalValue::WeakAnyLinkage,
-    Init,
-    ProtocolName);
+  PTGV = new llvm::GlobalVariable(CGM.getModule(), Init->getType(), false,
+                                  llvm::GlobalValue::WeakAnyLinkage, Init,
+                                  ProtocolName);
   PTGV->setSection(GetSectionName("__objc_protorefs",
                                   "coalesced,no_dead_strip"));
   PTGV->setVisibility(llvm::GlobalValue::HiddenVisibility);
   PTGV->setAlignment(Align.getQuantity());
+  if (!CGM.getTriple().isOSBinFormatMachO())
+    PTGV->setComdat(CGM.getModule().getOrInsertComdat(ProtocolName));
   CGM.addCompilerUsedGlobal(PTGV);
   return CGF.Builder.CreateAlignedLoad(PTGV, Align);
 }

clang/test/CodeGenObjC/protocol-comdat.m

@@ -4,16 +4,24 @@ @protocol P
 - (void) method;
 @end
 
+@protocol Q;
+@protocol R;
+
 @interface I<P>
 @end
 
 @implementation I
 - (void) method { }
 @end
 
+_Bool f(void) {
+  return @protocol(Q) == @protocol(R);
+}
 
 // CHECK: $"\01l_OBJC_PROTOCOL_$_P" = comdat any
 // CHECK: $"\01l_OBJC_LABEL_PROTOCOL_$_P" = comdat any
+// CHECK: $"\01l_OBJC_PROTOCOL_REFERENCE_$_Q" = comdat any
+// CHECK: $"\01l_OBJC_PROTOCOL_REFERENCE_$_R" = comdat any
 
 // CHECK: @"\01l_OBJC_PROTOCOL_$_P" = {{.*}}, comdat
 // CHECK: @"\01l_OBJC_LABEL_PROTOCOL_$_P" = {{.*}}, comdat