[MC] Thread unique_ptr<MCObjectWriter> through the create.*ObjectWriter

functions.

This makes the ownership of the resulting MCObjectWriter clear, and allows us
to remove one instance of MCObjectStreamer's bizarre "holding ownership via
someone else's reference" trick.

llvm-svn: 315327

3 files changed, 9 insertions, 4 deletions

diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
index 51ac410a9c8..e035c3b87a4 100644
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
@@ -66,7 +66,8 @@ public:
     llvm_unreachable("SystemZ does do not have assembler relaxation");
   }
   bool writeNopData(uint64_t Count, MCObjectWriter *OW) const override;
-  MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+  std::unique_ptr<MCObjectWriter>
+  createObjectWriter(raw_pwrite_stream &OS) const override {
     return createSystemZObjectWriter(OS, OSABI);
   }
 };
diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
index 166a3f0e1aa..238926d6c8e 100644
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCObjectWriter.cpp
@@ -13,6 +13,7 @@
 #include "llvm/MC/MCELFObjectWriter.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCFixup.h"
+#include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <cassert>
@@ -160,8 +161,8 @@ unsigned SystemZObjectWriter::getRelocType(MCContext &Ctx,
   }
 }
 
-MCObjectWriter *llvm::createSystemZObjectWriter(raw_pwrite_stream &OS,
-                                                uint8_t OSABI) {
+std::unique_ptr<MCObjectWriter>
+llvm::createSystemZObjectWriter(raw_pwrite_stream &OS, uint8_t OSABI) {
   return createELFObjectWriter(llvm::make_unique<SystemZObjectWriter>(OSABI),
                                OS, /*IsLittleEndian=*/false);
 }
diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.h b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.h
index dbca3485290..99b157e3727 100644
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.h
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.h
@@ -12,6 +12,8 @@
 
 #include "llvm/Support/DataTypes.h"
 
+#include <memory>
+
 namespace llvm {
 
 class MCAsmBackend;
@@ -91,7 +93,8 @@ MCAsmBackend *createSystemZMCAsmBackend(const Target &T,
                                         const Triple &TT, StringRef CPU,
                                         const MCTargetOptions &Options);
 
-MCObjectWriter *createSystemZObjectWriter(raw_pwrite_stream &OS, uint8_t OSABI);
+std::unique_ptr<MCObjectWriter> createSystemZObjectWriter(raw_pwrite_stream &OS,
+                                                          uint8_t OSABI);
 } // end namespace llvm
 
 // Defines symbolic names for SystemZ registers.