[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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315327 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 34 insertions, 22 deletions

diff --git a/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp b/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
index 733eac7c032..a5cecf03700 100644
--- a/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
@@ -389,7 +389,8 @@ public:
   ELFX86_32AsmBackend(const Target &T, uint8_t OSABI, StringRef CPU)
     : ELFX86AsmBackend(T, OSABI, CPU) {}
 
-  MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+  std::unique_ptr<MCObjectWriter>
+  createObjectWriter(raw_pwrite_stream &OS) const override {
     return createX86ELFObjectWriter(OS, /*IsELF64*/ false, OSABI, ELF::EM_386);
   }
 };
@@ -399,7 +400,8 @@ public:
   ELFX86_X32AsmBackend(const Target &T, uint8_t OSABI, StringRef CPU)
       : ELFX86AsmBackend(T, OSABI, CPU) {}
 
-  MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+  std::unique_ptr<MCObjectWriter>
+  createObjectWriter(raw_pwrite_stream &OS) const override {
     return createX86ELFObjectWriter(OS, /*IsELF64*/ false, OSABI,
                                     ELF::EM_X86_64);
   }
@@ -410,7 +412,8 @@ public:
   ELFX86_IAMCUAsmBackend(const Target &T, uint8_t OSABI, StringRef CPU)
       : ELFX86AsmBackend(T, OSABI, CPU) {}
 
-  MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+  std::unique_ptr<MCObjectWriter>
+  createObjectWriter(raw_pwrite_stream &OS) const override {
     return createX86ELFObjectWriter(OS, /*IsELF64*/ false, OSABI,
                                     ELF::EM_IAMCU);
   }
@@ -421,7 +424,8 @@ public:
   ELFX86_64AsmBackend(const Target &T, uint8_t OSABI, StringRef CPU)
     : ELFX86AsmBackend(T, OSABI, CPU) {}
 
-  MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+  std::unique_ptr<MCObjectWriter>
+  createObjectWriter(raw_pwrite_stream &OS) const override {
     return createX86ELFObjectWriter(OS, /*IsELF64*/ true, OSABI, ELF::EM_X86_64);
   }
 };
@@ -443,7 +447,8 @@ public:
         .Default(MCAsmBackend::getFixupKind(Name));
   }
 
-  MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+  std::unique_ptr<MCObjectWriter>
+  createObjectWriter(raw_pwrite_stream &OS) const override {
     return createX86WinCOFFObjectWriter(OS, Is64Bit);
   }
 };
@@ -804,7 +809,8 @@ public:
                          StringRef CPU)
       : DarwinX86AsmBackend(T, MRI, CPU, false) {}
 
-  MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+  std::unique_ptr<MCObjectWriter>
+  createObjectWriter(raw_pwrite_stream &OS) const override {
     return createX86MachObjectWriter(OS, /*Is64Bit=*/false,
                                      MachO::CPU_TYPE_I386,
                                      MachO::CPU_SUBTYPE_I386_ALL);
@@ -824,7 +830,8 @@ public:
                          StringRef CPU, MachO::CPUSubTypeX86 st)
       : DarwinX86AsmBackend(T, MRI, CPU, true), Subtype(st) {}
 
-  MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+  std::unique_ptr<MCObjectWriter>
+  createObjectWriter(raw_pwrite_stream &OS) const override {
     return createX86MachObjectWriter(OS, /*Is64Bit=*/true,
                                      MachO::CPU_TYPE_X86_64, Subtype);
   }
diff --git a/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp b/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
index 7e79941be34..4cdbae4d0d9 100644
--- a/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
@@ -15,6 +15,7 @@
 #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>
@@ -297,9 +298,9 @@ unsigned X86ELFObjectWriter::getRelocType(MCContext &Ctx, const MCValue &Target,
   return getRelocType32(Ctx, Modifier, getType32(Type), IsPCRel, Kind);
 }
 
-MCObjectWriter *llvm::createX86ELFObjectWriter(raw_pwrite_stream &OS,
-                                               bool IsELF64, uint8_t OSABI,
-                                               uint16_t EMachine) {
+std::unique_ptr<MCObjectWriter>
+llvm::createX86ELFObjectWriter(raw_pwrite_stream &OS, bool IsELF64,
+                               uint8_t OSABI, uint16_t EMachine) {
   auto MOTW = llvm::make_unique<X86ELFObjectWriter>(IsELF64, OSABI, EMachine);
   return createELFObjectWriter(std::move(MOTW), OS, /*IsLittleEndian=*/true);
 }
diff --git a/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.h b/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.h
index f73e734b9b0..82e70119ca5 100644
--- a/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.h
+++ b/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.h
@@ -86,16 +86,19 @@ MCStreamer *createX86WinCOFFStreamer(MCContext &C, MCAsmBackend &AB,
                                      bool RelaxAll, bool IncrementalLinkerCompatible);
 
 /// Construct an X86 Mach-O object writer.
-MCObjectWriter *createX86MachObjectWriter(raw_pwrite_stream &OS, bool Is64Bit,
-                                          uint32_t CPUType,
-                                          uint32_t CPUSubtype);
+std::unique_ptr<MCObjectWriter> createX86MachObjectWriter(raw_pwrite_stream &OS,
+                                                          bool Is64Bit,
+                                                          uint32_t CPUType,
+                                                          uint32_t CPUSubtype);
 
 /// Construct an X86 ELF object writer.
-MCObjectWriter *createX86ELFObjectWriter(raw_pwrite_stream &OS, bool IsELF64,
-                                         uint8_t OSABI, uint16_t EMachine);
+std::unique_ptr<MCObjectWriter> createX86ELFObjectWriter(raw_pwrite_stream &OS,
+                                                         bool IsELF64,
+                                                         uint8_t OSABI,
+                                                         uint16_t EMachine);
 /// Construct an X86 Win COFF object writer.
-MCObjectWriter *createX86WinCOFFObjectWriter(raw_pwrite_stream &OS,
-                                             bool Is64Bit);
+std::unique_ptr<MCObjectWriter>
+createX86WinCOFFObjectWriter(raw_pwrite_stream &OS, bool Is64Bit);
 
 /// Returns the sub or super register of a specific X86 register.
 /// e.g. getX86SubSuperRegister(X86::EAX, 16) returns X86::AX.
diff --git a/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp b/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
index 3b8d90ea36c..965f7de809b 100644
--- a/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
@@ -597,9 +597,9 @@ void X86MachObjectWriter::RecordX86Relocation(MachObjectWriter *Writer,
   Writer->addRelocation(RelSymbol, Fragment->getParent(), MRE);
 }
 
-MCObjectWriter *llvm::createX86MachObjectWriter(raw_pwrite_stream &OS,
-                                                bool Is64Bit, uint32_t CPUType,
-                                                uint32_t CPUSubtype) {
+std::unique_ptr<MCObjectWriter>
+llvm::createX86MachObjectWriter(raw_pwrite_stream &OS, bool Is64Bit,
+                                uint32_t CPUType, uint32_t CPUSubtype) {
   return createMachObjectWriter(
       llvm::make_unique<X86MachObjectWriter>(Is64Bit, CPUType, CPUSubtype), OS,
       /*IsLittleEndian=*/true);
diff --git a/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp b/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp
index d138bdc8d39..5139bb46b56 100644
--- a/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp
@@ -13,6 +13,7 @@
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCFixup.h"
+#include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/MC/MCWinCOFFObjectWriter.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -104,8 +105,8 @@ unsigned X86WinCOFFObjectWriter::getRelocType(MCContext &Ctx,
     llvm_unreachable("Unsupported COFF machine type.");
 }
 
-MCObjectWriter *llvm::createX86WinCOFFObjectWriter(raw_pwrite_stream &OS,
-                                                   bool Is64Bit) {
+std::unique_ptr<MCObjectWriter>
+llvm::createX86WinCOFFObjectWriter(raw_pwrite_stream &OS, bool Is64Bit) {
   auto MOTW = llvm::make_unique<X86WinCOFFObjectWriter>(Is64Bit);
   return createWinCOFFObjectWriter(std::move(MOTW), OS);
 }