r354678 - CodeGen: use COMDAT for block copy/destroy helpers

[Saleem Abdulrasool via cfe-commits]

Author: compnerd
Date: Fri Feb 22 08:29:50 2019
New Revision: 354678

URL: http://llvm.org/viewvc/llvm-project?rev=354678&view=rev
Log:
CodeGen: use COMDAT for block copy/destroy helpers

SVN r339438 added support to deduplicate the helpers by using a consistent
naming scheme and using LinkOnceODR semantics.  This works on ELF by means of
weak linking semantics, and entirely does not work on PE/COFF where you end up
with multiply defined strong symbols, which is a strong error on PE/COFF.
Assign the functions a COMDAT group so that they can be uniqued by the linker.
This fixes the use of blocks in CoreFoundation on Windows.

Modified:
    cfe/trunk/lib/CodeGen/CGBlocks.cpp
    cfe/trunk/test/CodeGen/blocks-1.c

Modified: cfe/trunk/lib/CodeGen/CGBlocks.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGBlocks.cpp?rev=354678&r1=354677&r2=354678&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGBlocks.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGBlocks.cpp Fri Feb 22 08:29:50 2019
@@ -2016,6 +2016,8 @@ CodeGenFunction::GenerateCopyHelperFunct
   llvm::Function *Fn =
     llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
                            FuncName, &CGM.getModule());
+  if (CGM.supportsCOMDAT())
+    Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
 
   IdentifierInfo *II = &C.Idents.get(FuncName);
 
@@ -2207,6 +2209,8 @@ CodeGenFunction::GenerateDestroyHelperFu
   llvm::Function *Fn =
     llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
                            FuncName, &CGM.getModule());
+  if (CGM.supportsCOMDAT())
+    Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
 
   IdentifierInfo *II = &C.Idents.get(FuncName);
 

Modified: cfe/trunk/test/CodeGen/blocks-1.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/blocks-1.c?rev=354678&r1=354677&r2=354678&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/blocks-1.c (original)
+++ cfe/trunk/test/CodeGen/blocks-1.c Fri Feb 22 08:29:50 2019
@@ -1,10 +1,19 @@
-// RUN: %clang_cc1 %s -emit-llvm -o %t -fblocks
+// RUN: %clang_cc1 -triple thumbv7-apple-ios %s -emit-llvm -o %t -fblocks
 // RUN: grep "_Block_object_dispose" %t | count 12
 // RUN: grep "__copy_helper_block_" %t | count 9
 // RUN: grep "__destroy_helper_block_" %t | count 9
 // RUN: grep "__Block_byref_object_copy_" %t | count 2
 // RUN: grep "__Block_byref_object_dispose_" %t | count 2
 // RUN: grep "i32 135)" %t | count 2
+// RUN: grep "_Block_object_assign" %t | count 5
+
+// RUN: %clang_cc1 -triple thumbv7-unknown-windows %s -emit-llvm -o %t -fblocks
+// RUN: grep "_Block_object_dispose" %t | count 12
+// RUN: grep "__copy_helper_block_" %t | count 11
+// RUN: grep "__destroy_helper_block_" %t | count 11
+// RUN: grep "__Block_byref_object_copy_" %t | count 2
+// RUN: grep "__Block_byref_object_dispose_" %t | count 2
+// RUN: grep "i32 135)" %t | count 2
 // RUN: grep "_Block_object_assign" %t | count 5
 
 int printf(const char *, ...);