[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

6 files changed, 20 insertions, 15 deletions

diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index 795c21f08b9..e11eaaa3060 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -1387,8 +1387,9 @@ bool ELFObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
                                                                 InSet, IsPCRel);
 }
 
-MCObjectWriter *
+std::unique_ptr<MCObjectWriter>
 llvm::createELFObjectWriter(std::unique_ptr<MCELFObjectTargetWriter> MOTW,
                             raw_pwrite_stream &OS, bool IsLittleEndian) {
-  return new ELFObjectWriter(std::move(MOTW), OS, IsLittleEndian);
+  return llvm::make_unique<ELFObjectWriter>(std::move(MOTW), OS,
+                                            IsLittleEndian);
 }
diff --git a/llvm/lib/MC/MCELFStreamer.cpp b/llvm/lib/MC/MCELFStreamer.cpp
index 50c1f6e79f8..76976cab466 100644
--- a/llvm/lib/MC/MCELFStreamer.cpp
+++ b/llvm/lib/MC/MCELFStreamer.cpp
@@ -62,12 +62,13 @@ void MCELFStreamer::mergeFragment(MCDataFragment *DF,
     if (RequiredBundlePadding > 0) {
       SmallString<256> Code;
       raw_svector_ostream VecOS(Code);
-      MCObjectWriter *OW = Assembler.getBackend().createObjectWriter(VecOS);
+      {
+        auto OW = Assembler.getBackend().createObjectWriter(VecOS);
 
-      EF->setBundlePadding(static_cast<uint8_t>(RequiredBundlePadding));
+        EF->setBundlePadding(static_cast<uint8_t>(RequiredBundlePadding));
 
-      Assembler.writeFragmentPadding(*EF, FSize, OW);
-      delete OW;
+        Assembler.writeFragmentPadding(*EF, FSize, OW.get());
+      }
 
       DF->getContents().append(Code.begin(), Code.end());
     }
diff --git a/llvm/lib/MC/MCObjectStreamer.cpp b/llvm/lib/MC/MCObjectStreamer.cpp
index 65e5b839cae..46d57265d85 100644
--- a/llvm/lib/MC/MCObjectStreamer.cpp
+++ b/llvm/lib/MC/MCObjectStreamer.cpp
@@ -28,15 +28,14 @@ using namespace llvm;
 MCObjectStreamer::MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB,
                                    raw_pwrite_stream &OS,
                                    MCCodeEmitter *Emitter_)
-    : MCStreamer(Context),
+    : MCStreamer(Context), ObjectWriter(TAB.createObjectWriter(OS)),
       Assembler(llvm::make_unique<MCAssembler>(Context, TAB, *Emitter_,
-                                               *TAB.createObjectWriter(OS))),
+                                               *ObjectWriter)),
       EmitEHFrame(true), EmitDebugFrame(false) {}
 
 MCObjectStreamer::~MCObjectStreamer() {
   delete &Assembler->getBackend();
   delete &Assembler->getEmitter();
-  delete &Assembler->getWriter();
 }
 
 void MCObjectStreamer::flushPendingLabels(MCFragment *F, uint64_t FOffset) {
diff --git a/llvm/lib/MC/MachObjectWriter.cpp b/llvm/lib/MC/MachObjectWriter.cpp
index c2196a77e18..7dbb84e166f 100644
--- a/llvm/lib/MC/MachObjectWriter.cpp
+++ b/llvm/lib/MC/MachObjectWriter.cpp
@@ -994,8 +994,9 @@ void MachObjectWriter::writeObject(MCAssembler &Asm,
   }
 }
 
-MCObjectWriter *
+std::unique_ptr<MCObjectWriter>
 llvm::createMachObjectWriter(std::unique_ptr<MCMachObjectTargetWriter> MOTW,
                              raw_pwrite_stream &OS, bool IsLittleEndian) {
-  return new MachObjectWriter(std::move(MOTW), OS, IsLittleEndian);
+  return llvm::make_unique<MachObjectWriter>(std::move(MOTW), OS,
+                                             IsLittleEndian);
 }
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index 02d8bfbe1de..55e7c93c87e 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -1317,8 +1317,11 @@ void WasmObjectWriter::writeObject(MCAssembler &Asm,
   // TODO: Translate debug sections to the output.
 }
 
-MCObjectWriter *
+std::unique_ptr<MCObjectWriter>
 llvm::createWasmObjectWriter(std::unique_ptr<MCWasmObjectTargetWriter> MOTW,
                              raw_pwrite_stream &OS) {
-  return new WasmObjectWriter(std::move(MOTW), OS);
+  // FIXME: Can't use make_unique<WasmObjectWriter>(...) as WasmObjectWriter's
+  //        destructor is private. Is that necessary?
+  return std::unique_ptr<MCObjectWriter>(
+      new WasmObjectWriter(std::move(MOTW), OS));
 }
diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
index 64f7317cf49..9f1db46939c 100644
--- a/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -1085,7 +1085,7 @@ void MCWinCOFFObjectTargetWriter::anchor() {}
 //------------------------------------------------------------------------------
 // WinCOFFObjectWriter factory function
 
-MCObjectWriter *llvm::createWinCOFFObjectWriter(
+std::unique_ptr<MCObjectWriter> llvm::createWinCOFFObjectWriter(
     std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW, raw_pwrite_stream &OS) {
-  return new WinCOFFObjectWriter(std::move(MOTW), OS);
+  return llvm::make_unique<WinCOFFObjectWriter>(std::move(MOTW), OS);
 }