Handle use side of __objc_exception__ attribute; when using an

exception with this attribute we don't need to emit a weak definition
for the exception type information.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68513 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 19 insertions, 0 deletions

diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index cf2d8da022..f410e213cb 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -5547,6 +5547,14 @@ void CGObjCNonFragileABIMac::EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
   CGF.Builder.ClearInsertionPoint();
 }
 
+static bool hasObjCExceptionAttribute(const ObjCInterfaceDecl *OID) {
+  if (OID->getAttr<ObjCExceptionAttr>())
+    return true;
+  if (const ObjCInterfaceDecl *Super = OID->getSuperClass())
+    return hasObjCExceptionAttribute(Super);
+  return false;
+}
+
 llvm::Value *
 CGObjCNonFragileABIMac::GetInterfaceEHType(const ObjCInterfaceType *IT) {
   const ObjCInterfaceDecl *ID = IT->getDecl();
@@ -5554,6 +5562,17 @@ CGObjCNonFragileABIMac::GetInterfaceEHType(const ObjCInterfaceType *IT) {
   if (Entry)
     return Entry;
 
+  // If this type (or a super class) has the __objc_exception__
+  // attribute, emit an external reference.
+  if (hasObjCExceptionAttribute(IT->getDecl()))
+    return Entry = 
+      new llvm::GlobalVariable(ObjCTypes.EHTypeTy, false,
+                               llvm::GlobalValue::ExternalLinkage,
+                               0, 
+                               (std::string("OBJC_EHTYPE_$_") + 
+                                ID->getIdentifier()->getName()),
+                               &CGM.getModule());
+
   std::string ClassName(getClassSymbolPrefix() + ID->getNameAsString());
   std::string VTableName = "objc_ehtype_vtable";
   llvm::GlobalVariable *VTableGV =