Bitcode: Don't create comdats when autoupgrading macho bitcode

Don't infer COMDAT groups from older bitcode if the target is macho,
it doesn't have COMDATs.

llvm-svn: 226546

3 files changed, 20 insertions, 2 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index f8625e1034f..9e27225df79 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -11,6 +11,7 @@
 #include "BitcodeReader.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Triple.h"
 #include "llvm/Bitcode/LLVMBitCodes.h"
 #include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/Constants.h"
@@ -1106,6 +1107,8 @@ std::error_code BitcodeReader::ParseValueSymbolTable() {
 
   SmallVector<uint64_t, 64> Record;
 
+  Triple TT(TheModule->getTargetTriple());
+
   // Read all the records for this value table.
   SmallString<128> ValueName;
   while (1) {
@@ -1137,8 +1140,12 @@ std::error_code BitcodeReader::ParseValueSymbolTable() {
 
       V->setName(StringRef(ValueName.data(), ValueName.size()));
       if (auto *GO = dyn_cast<GlobalObject>(V)) {
-        if (GO->getComdat() == reinterpret_cast<Comdat *>(1))
-          GO->setComdat(TheModule->getOrInsertComdat(V->getName()));
+        if (GO->getComdat() == reinterpret_cast<Comdat *>(1)) {
+          if (TT.isOSBinFormatMachO())
+            GO->setComdat(nullptr);
+          else
+            GO->setComdat(TheModule->getOrInsertComdat(V->getName()));
+        }
       }
       ValueName.clear();
       break;
diff --git a/llvm/test/Bitcode/weak-macho-3.5.ll b/llvm/test/Bitcode/weak-macho-3.5.ll
new file mode 100644
index 00000000000..0c09fe4cd9d
--- /dev/null
+++ b/llvm/test/Bitcode/weak-macho-3.5.ll
@@ -0,0 +1,11 @@
+; RUN:  llvm-dis < %s.bc| FileCheck %s
+
+; weak-macho-3.5.ll.bc was generated by passing this file to llvm-as-3.5
+; The test checks that LLVM does not place weak GlobalVariables into Comdats for
+; macho object files, they don't support it.
+
+target triple = "x86_64-apple-macosx10.9.0"
+; CHECK: target triple = "x86_64-apple-macosx10.9.0"
+
+@x = weak global i32 0
+; CHECK: @x = weak global i32 0{{$}}
diff --git a/llvm/test/Bitcode/weak-macho-3.5.ll.bc b/llvm/test/Bitcode/weak-macho-3.5.ll.bc
new file mode 100644
index 00000000000..ee660723577
--- /dev/null
+++ b/llvm/test/Bitcode/weak-macho-3.5.ll.bc