Fix leaks in LLVMCreateDisasmCPUFeatures

[scott.linder]

Summary

Construct the unique_ptr's in LLVMCreateDisasmCPUFeatures to avoid leaks if it fails.

lib/MC/MCDisassembler/Disassembler.h

private:
   // The CPU string.
   std::string CPU;
 
 public:
   // Comment stream and backing vector.
   SmallString<128> CommentsToEmit;
   raw_svector_ostream CommentStream;
 
-  LLVMDisasmContext(std::string tripleName, void *disInfo, int tagType,
-                    LLVMOpInfoCallback getOpInfo,
-                    LLVMSymbolLookupCallback symbolLookUp,
-                    const Target *theTarget, const MCAsmInfo *mAI,
-                    const MCRegisterInfo *mRI, const MCSubtargetInfo *mSI,
-                    const MCInstrInfo *mII, llvm::MCContext *ctx,
-                    const MCDisassembler *disAsm, MCInstPrinter *iP)
-      : TripleName(std::move(tripleName)), DisInfo(disInfo), TagType(tagType),
-        GetOpInfo(getOpInfo), SymbolLookUp(symbolLookUp), TheTarget(theTarget),
-        Options(0), CommentStream(CommentsToEmit) {
-    MAI.reset(mAI);
-    MRI.reset(mRI);
-    MSI.reset(mSI);
-    MII.reset(mII);
-    Ctx.reset(ctx);
-    DisAsm.reset(disAsm);
-    IP.reset(iP);
-  }
+  LLVMDisasmContext(std::string TripleName, void *DisInfo, int TagType,
+                    LLVMOpInfoCallback GetOpInfo,
+                    LLVMSymbolLookupCallback SymbolLookUp,
+                    const Target *TheTarget,
+                    std::unique_ptr<const MCAsmInfo> &&MAI,
+                    std::unique_ptr<const MCRegisterInfo> &&MRI,
+                    std::unique_ptr<const MCSubtargetInfo> &&MSI,
+                    std::unique_ptr<const MCInstrInfo> &&MII,
+                    std::unique_ptr<const llvm::MCContext> &&Ctx,
+                    std::unique_ptr<const MCDisassembler> &&DisAsm,
+                    std::unique_ptr<MCInstPrinter> &&IP)
+      : TripleName(std::move(TripleName)), DisInfo(DisInfo), TagType(TagType),
+        GetOpInfo(GetOpInfo), SymbolLookUp(SymbolLookUp), TheTarget(TheTarget),
+        MAI(std::move(MAI)), MRI(std::move(MRI)), MSI(std::move(MSI)),
+        MII(std::move(MII)), Ctx(std::move(Ctx)), DisAsm(std::move(DisAsm)),
+        IP(std::move(IP)), Options(0), CommentStream(CommentsToEmit) {}
   const std::string &getTripleName() const { return TripleName; }
   void *getDisInfo() const { return DisInfo; }
   int getTagType() const { return TagType; }
   LLVMOpInfoCallback getGetOpInfo() const { return GetOpInfo; }
   LLVMSymbolLookupCallback getSymbolLookupCallback() const {
     return SymbolLookUp;
   }
   const Target *getTarget() const { return TheTarget; }

lib/MC/MCDisassembler/Disassembler.cpp

LLVMCreateDisasmCPUFeatures(const char *TT, const char *CPU,
                             LLVMOpInfoCallback GetOpInfo,
                             LLVMSymbolLookupCallback SymbolLookUp) {
   // Get the target.
   std::string Error;
   const Target *TheTarget = TargetRegistry::lookupTarget(TT, Error);
   if (!TheTarget)
     return nullptr;
 
-  const MCRegisterInfo *MRI = TheTarget->createMCRegInfo(TT);
+  std::unique_ptr<const MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TT));
   if (!MRI)
     return nullptr;
 
   // Get the assembler info needed to setup the MCContext.
-  const MCAsmInfo *MAI = TheTarget->createMCAsmInfo(*MRI, TT);
+  std::unique_ptr<const MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, TT));
   if (!MAI)
     return nullptr;
 
-  const MCInstrInfo *MII = TheTarget->createMCInstrInfo();
+  std::unique_ptr<const MCInstrInfo> MII(TheTarget->createMCInstrInfo());
   if (!MII)
     return nullptr;
 
-  const MCSubtargetInfo *STI =
-      TheTarget->createMCSubtargetInfo(TT, CPU, Features);
+  std::unique_ptr<const MCSubtargetInfo> STI(
+      TheTarget->createMCSubtargetInfo(TT, CPU, Features));
   if (!STI)
     return nullptr;
 
   // Set up the MCContext for creating symbols and MCExpr's.
-  MCContext *Ctx = new MCContext(MAI, MRI, nullptr);
+  std::unique_ptr<MCContext> Ctx(new MCContext(MAI.get(), MRI.get(), nullptr));
   if (!Ctx)
     return nullptr;
 
   // Set up disassembler.
-  MCDisassembler *DisAsm = TheTarget->createMCDisassembler(*STI, *Ctx);
+  std::unique_ptr<MCDisassembler> DisAsm(
+      TheTarget->createMCDisassembler(*STI, *Ctx));
   if (!DisAsm)
     return nullptr;
 
   std::unique_ptr<MCRelocationInfo> RelInfo(
       TheTarget->createMCRelocationInfo(TT, *Ctx));
   if (!RelInfo)
     return nullptr;
 
   std::unique_ptr<MCSymbolizer> Symbolizer(TheTarget->createMCSymbolizer(
-      TT, GetOpInfo, SymbolLookUp, DisInfo, Ctx, std::move(RelInfo)));
+      TT, GetOpInfo, SymbolLookUp, DisInfo, Ctx.get(), std::move(RelInfo)));
   DisAsm->setSymbolizer(std::move(Symbolizer));
 
   // Set up the instruction printer.
   int AsmPrinterVariant = MAI->getAssemblerDialect();
-  MCInstPrinter *IP = TheTarget->createMCInstPrinter(
-      Triple(TT), AsmPrinterVariant, *MAI, *MII, *MRI);
+  std::unique_ptr<MCInstPrinter> IP(TheTarget->createMCInstPrinter(
+      Triple(TT), AsmPrinterVariant, *MAI, *MII, *MRI));
   if (!IP)
     return nullptr;
 
-  LLVMDisasmContext *DC =
-      new LLVMDisasmContext(TT, DisInfo, TagType, GetOpInfo, SymbolLookUp,
-                            TheTarget, MAI, MRI, STI, MII, Ctx, DisAsm, IP);
+  LLVMDisasmContext *DC = new LLVMDisasmContext(
+      TT, DisInfo, TagType, GetOpInfo, SymbolLookUp, TheTarget, std::move(MAI),
+      std::move(MRI), std::move(STI), std::move(MII), std::move(Ctx),
+      std::move(DisAsm), std::move(IP));
   if (!DC)
     return nullptr;
 
   DC->setCPU(CPU);
   return DC;
 }
 
 LLVMDisasmContextRef