From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Mon, 19 Jan 2015 14:02:14 +0000 (+0000)
Subject: Add comdat to thunks.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ba294eb8f9baa1ff747e356e165a682a03a4d4ec;p=clang

Add comdat to thunks.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@226465 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGVTables.cpp b/lib/CodeGen/CGVTables.cpp
index 5416d44167..7724467765 100644
--- a/lib/CodeGen/CGVTables.cpp
+++ b/lib/CodeGen/CGVTables.cpp
@@ -377,7 +377,10 @@ void CodeGenFunction::GenerateThunk(llvm::Function *Fn,
 
   // Set the right linkage.
   CGM.setFunctionLinkage(GD, Fn);
-  
+
+  if (CGM.supportsCOMDAT() && Fn->isWeakForLinker())
+    Fn->setComdat(CGM.getModule().getOrInsertComdat(Fn->getName()));
+
   // Set the right visibility.
   const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
   setThunkVisibility(CGM, MD, Thunk, Fn);
diff --git a/test/CodeGenCXX/microsoft-abi-thunks.cpp b/test/CodeGenCXX/microsoft-abi-thunks.cpp
index 39a6743089..5ca04fe504 100644
--- a/test/CodeGenCXX/microsoft-abi-thunks.cpp
+++ b/test/CodeGenCXX/microsoft-abi-thunks.cpp
@@ -33,10 +33,10 @@ struct C : A, B {
   virtual ~C();
   // MANGLING-DAG: declare {{.*}} @"\01??1C@@UAE@XZ"({{.*}})
   // MANGLING-DAG: define {{.*}} @"\01??_GC@@UAEPAXI@Z"({{.*}})
-  // MANGLING-DAG: define {{.*}} @"\01??_EC@@W3AEPAXI@Z"({{.*}})
+  // MANGLING-DAG: define {{.*}} @"\01??_EC@@W3AEPAXI@Z"({{.*}}) {{.*}} comdat
   // MANGLING-X64-DAG: declare {{.*}} @"\01??1C@@UEAA@XZ"({{.*}})
   // MANGLING-X64-DAG: define {{.*}} @"\01??_GC@@UEAAPEAXI@Z"({{.*}})
-  // MANGLING-X64-DAG: define {{.*}} @"\01??_EC@@W7EAAPEAXI@Z"({{.*}})
+  // MANGLING-X64-DAG: define {{.*}} @"\01??_EC@@W7EAAPEAXI@Z"({{.*}}) {{.*}} comdat
 
   // Overrides public_f() of two subobjects with distinct vfptrs, thus needs a thunk.
   virtual void public_f();
@@ -61,7 +61,7 @@ struct C : A, B {
 
 C::C() {}  // Emits vftable and forces thunk generation.
 
-// CODEGEN-LABEL: define linkonce_odr x86_thiscallcc i8* @"\01??_EC@@W3AEPAXI@Z"(%struct.C* %this, i32 %should_call_delete)
+// CODEGEN-LABEL: define linkonce_odr x86_thiscallcc i8* @"\01??_EC@@W3AEPAXI@Z"(%struct.C* %this, i32 %should_call_delete) {{.*}} comdat
 // CODEGEN:   getelementptr i8* {{.*}}, i32 -4
 // FIXME: should actually call _EC, not _GC.
 // CODEGEN:   call x86_thiscallcc i8* @"\01??_GC@@UAEPAXI@Z"