llvm/lib/InterfaceStub/IFSHandler.cpp - llvm-project - Git at Google

 //===- IFSHandler.cpp -----------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===-----------------------------------------------------------------------===/

 #include "llvm/InterfaceStub/IFSHandler.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/InterfaceStub/IFSStub.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/LineIterator.h"
 #include "llvm/Support/YAMLTraits.h"

 using namespace llvm;
 using namespace llvm::ifs;

 LLVM_YAML_IS_SEQUENCE_VECTOR(IFSSymbol)

 namespace llvm {
 namespace yaml {

 /// YAML traits for ELFSymbolType.
 template <> struct ScalarEnumerationTraits<IFSSymbolType> {
   static void enumeration(IO &IO, IFSSymbolType &SymbolType) {
     IO.enumCase(SymbolType, "NoType", IFSSymbolType::NoType);
     IO.enumCase(SymbolType, "Func", IFSSymbolType::Func);
     IO.enumCase(SymbolType, "Object", IFSSymbolType::Object);
     IO.enumCase(SymbolType, "TLS", IFSSymbolType::TLS);
     IO.enumCase(SymbolType, "Unknown", IFSSymbolType::Unknown);
     // Treat other symbol types as noise, and map to Unknown.
     if (!IO.outputting() && IO.matchEnumFallback())
       SymbolType = IFSSymbolType::Unknown;
   }
 };

 template <> struct ScalarTraits<IFSEndiannessType> {
   static void output(const IFSEndiannessType &Value, void *,
                      llvm::raw_ostream &Out) {
     switch (Value) {
     case IFSEndiannessType::Big:
       Out << "big";
       break;
     case IFSEndiannessType::Little:
       Out << "little";
       break;
     default:
       llvm_unreachable("Unsupported endianness");
     }
   }

   static StringRef input(StringRef Scalar, void *, IFSEndiannessType &Value) {
     Value = StringSwitch<IFSEndiannessType>(Scalar)
                 .Case("big", IFSEndiannessType::Big)
                 .Case("little", IFSEndiannessType::Little)
                 .Default(IFSEndiannessType::Unknown);
     if (Value == IFSEndiannessType::Unknown) {
       return "Unsupported endianness";
     }
     return StringRef();
   }

   static QuotingType mustQuote(StringRef) { return QuotingType::None; }
 };

 template <> struct ScalarTraits<IFSBitWidthType> {
   static void output(const IFSBitWidthType &Value, void *,
                      llvm::raw_ostream &Out) {
     switch (Value) {
     case IFSBitWidthType::IFS32:
       Out << "32";
       break;
     case IFSBitWidthType::IFS64:
       Out << "64";
       break;
     default:
       llvm_unreachable("Unsupported bit width");
     }
   }

   static StringRef input(StringRef Scalar, void *, IFSBitWidthType &Value) {
     Value = StringSwitch<IFSBitWidthType>(Scalar)
                 .Case("32", IFSBitWidthType::IFS32)
                 .Case("64", IFSBitWidthType::IFS64)
                 .Default(IFSBitWidthType::Unknown);
     if (Value == IFSBitWidthType::Unknown) {
       return "Unsupported bit width";
     }
     return StringRef();
   }

   static QuotingType mustQuote(StringRef) { return QuotingType::None; }
 };

 template <> struct MappingTraits<IFSTarget> {
   static void mapping(IO &IO, IFSTarget &Target) {
     IO.mapOptional("ObjectFormat", Target.ObjectFormat);
     IO.mapOptional("Arch", Target.ArchString);
     IO.mapOptional("Endianness", Target.Endianness);
     IO.mapOptional("BitWidth", Target.BitWidth);
   }

   // Compacts symbol information into a single line.
   static const bool flow = true; // NOLINT(readability-identifier-naming)
 };

 /// YAML traits for ELFSymbol.
 template <> struct MappingTraits<IFSSymbol> {
   static void mapping(IO &IO, IFSSymbol &Symbol) {
     IO.mapRequired("Name", Symbol.Name);
     IO.mapRequired("Type", Symbol.Type);
     // The need for symbol size depends on the symbol type.
     if (Symbol.Type == IFSSymbolType::NoType) {
       IO.mapOptional("Size", Symbol.Size, (uint64_t)0);
     } else if (Symbol.Type == IFSSymbolType::Func) {
       Symbol.Size = 0;
     } else {
       IO.mapRequired("Size", Symbol.Size);
     }
     IO.mapOptional("Undefined", Symbol.Undefined, false);
     IO.mapOptional("Weak", Symbol.Weak, false);
     IO.mapOptional("Warning", Symbol.Warning);
   }

   // Compacts symbol information into a single line.
   static const bool flow = true; // NOLINT(readability-identifier-naming)
 };

 /// YAML traits for ELFStub objects.
 template <> struct MappingTraits<IFSStub> {
   static void mapping(IO &IO, IFSStub &Stub) {
     if (!IO.mapTag("!ifs-v1", true))
       IO.setError("Not a .tbe YAML file.");
     IO.mapRequired("IfsVersion", Stub.IfsVersion);
     IO.mapOptional("SoName", Stub.SoName);
     IO.mapOptional("Target", Stub.Target);
     IO.mapOptional("NeededLibs", Stub.NeededLibs);
     IO.mapRequired("Symbols", Stub.Symbols);
   }
 };

 /// YAML traits for ELFStubTriple objects.
 template <> struct MappingTraits<IFSStubTriple> {
   static void mapping(IO &IO, IFSStubTriple &Stub) {
     if (!IO.mapTag("!ifs-v1", true))
       IO.setError("Not a .tbe YAML file.");
     IO.mapRequired("IfsVersion", Stub.IfsVersion);
     IO.mapOptional("SoName", Stub.SoName);
     IO.mapOptional("Target", Stub.Target.Triple);
     IO.mapOptional("NeededLibs", Stub.NeededLibs);
     IO.mapRequired("Symbols", Stub.Symbols);
   }
 };
 } // end namespace yaml
 } // end namespace llvm

 /// Attempt to determine if a Text stub uses target triple.
 bool usesTriple(StringRef Buf) {
   for (line_iterator I(MemoryBufferRef(Buf, "ELFStub")); !I.is_at_eof(); ++I) {
     StringRef Line = (*I).trim();
     if (Line.startswith("Target:")) {
       if (Line == "Target:" || Line.contains("{")) {
         return false;
       }
     }
   }
   return true;
 }

 Expected<std::unique_ptr<IFSStub>> ifs::readIFSFromBuffer(StringRef Buf) {
   yaml::Input YamlIn(Buf);
   std::unique_ptr<IFSStubTriple> Stub(new IFSStubTriple());
   if (usesTriple(Buf)) {
     YamlIn >> *Stub;
   } else {
     YamlIn >> *static_cast<IFSStub *>(Stub.get());
   }
   if (std::error_code Err = YamlIn.error()) {
     return createStringError(Err, "YAML failed reading as IFS");
   }

   if (Stub->IfsVersion > IFSVersionCurrent)
     return make_error<StringError>(
         "IFS version " + Stub->IfsVersion.getAsString() + " is unsupported.",
         std::make_error_code(std::errc::invalid_argument));
   if (Stub->Target.ArchString) {
     Stub->Target.Arch =
         ELF::convertArchNameToEMachine(Stub->Target.ArchString.getValue());
   }
   return std::move(Stub);
 }

 Error ifs::writeIFSToOutputStream(raw_ostream &OS, const IFSStub &Stub) {
   yaml::Output YamlOut(OS, NULL, /*WrapColumn =*/0);
   std::unique_ptr<IFSStubTriple> CopyStub(new IFSStubTriple(Stub));
   if (Stub.Target.Arch) {
     CopyStub->Target.ArchString = std::string(
         ELF::convertEMachineToArchName(Stub.Target.Arch.getValue()));
   }
   IFSTarget Target = Stub.Target;

   if (CopyStub->Target.Triple ||
       (!CopyStub->Target.ArchString && !CopyStub->Target.Endianness &&
        !CopyStub->Target.BitWidth))
     YamlOut << *CopyStub;
   else
     YamlOut << *static_cast<IFSStub *>(CopyStub.get());
   return Error::success();
 }

 Error ifs::overrideIFSTarget(IFSStub &Stub, Optional<IFSArch> OverrideArch,
                              Optional<IFSEndiannessType> OverrideEndianness,
                              Optional<IFSBitWidthType> OverrideBitWidth,
                              Optional<std::string> OverrideTriple) {
   std::error_code OverrideEC(1, std::generic_category());
   if (OverrideArch) {
     if (Stub.Target.Arch &&
         Stub.Target.Arch.getValue() != OverrideArch.getValue()) {
       return make_error<StringError>(
           "Supplied Arch conflicts with the text stub", OverrideEC);
     }
     Stub.Target.Arch = OverrideArch.getValue();
   }
   if (OverrideEndianness) {
     if (Stub.Target.Endianness &&
         Stub.Target.Endianness.getValue() != OverrideEndianness.getValue()) {
       return make_error<StringError>(
           "Supplied Endianness conflicts with the text stub", OverrideEC);
     }
     Stub.Target.Endianness = OverrideEndianness.getValue();
   }
   if (OverrideBitWidth) {
     if (Stub.Target.BitWidth &&
         Stub.Target.BitWidth.getValue() != OverrideBitWidth.getValue()) {
       return make_error<StringError>(
           "Supplied BitWidth conflicts with the text stub", OverrideEC);
     }
     Stub.Target.BitWidth = OverrideBitWidth.getValue();
   }
   if (OverrideTriple) {
     if (Stub.Target.Triple &&
         Stub.Target.Triple.getValue() != OverrideTriple.getValue()) {
       return make_error<StringError>(
           "Supplied Triple conflicts with the text stub", OverrideEC);
     }
     Stub.Target.Triple = OverrideTriple.getValue();
   }
   return Error::success();
 }

 Error ifs::validateIFSTarget(IFSStub &Stub, bool ParseTriple) {
   std::error_code ValidationEC(1, std::generic_category());
   if (Stub.Target.Triple) {
     if (Stub.Target.Arch || Stub.Target.BitWidth || Stub.Target.Endianness ||
         Stub.Target.ObjectFormat) {
       return make_error<StringError>(
           "Target triple cannot be used simultaneously with ELF target format",
           ValidationEC);
     }
     if (ParseTriple) {
       IFSTarget TargetFromTriple = parseTriple(Stub.Target.Triple.getValue());
       Stub.Target.Arch = TargetFromTriple.Arch;
       Stub.Target.BitWidth = TargetFromTriple.BitWidth;
       Stub.Target.Endianness = TargetFromTriple.Endianness;
     }
     return Error::success();
   }
   if (!Stub.Target.Arch || !Stub.Target.BitWidth || !Stub.Target.Endianness) {
     // TODO: unify the error message.
     if (!Stub.Target.Arch) {
       return make_error<StringError>("Arch is not defined in the text stub",
                                      ValidationEC);
     }
     if (!Stub.Target.BitWidth) {
       return make_error<StringError>("BitWidth is not defined in the text stub",
                                      ValidationEC);
     }
     if (!Stub.Target.Endianness) {
       return make_error<StringError>(
           "Endianness is not defined in the text stub", ValidationEC);
     }
   }
   return Error::success();
 }

 IFSTarget ifs::parseTriple(StringRef TripleStr) {
   Triple IFSTriple(TripleStr);
   IFSTarget RetTarget;
   // TODO: Implement a Triple Arch enum to e_machine map.
   switch (IFSTriple.getArch()) {
   case Triple::ArchType::aarch64:
     RetTarget.Arch = (IFSArch)ELF::EM_AARCH64;
     break;
   case Triple::ArchType::x86_64:
     RetTarget.Arch = (IFSArch)ELF::EM_X86_64;
     break;
   default:
     RetTarget.Arch = (IFSArch)ELF::EM_NONE;
   }
   RetTarget.Endianness = IFSTriple.isLittleEndian() ? IFSEndiannessType::Little
                                                     : IFSEndiannessType::Big;
   RetTarget.BitWidth =
       IFSTriple.isArch64Bit() ? IFSBitWidthType::IFS64 : IFSBitWidthType::IFS32;
   return RetTarget;
 }

 void ifs::stripIFSTarget(IFSStub &Stub, bool StripTriple, bool StripArch,
                          bool StripEndianness, bool StripBitWidth) {
   if (StripTriple || StripArch) {
     Stub.Target.Arch.reset();
     Stub.Target.ArchString.reset();
   }
   if (StripTriple || StripEndianness) {
     Stub.Target.Endianness.reset();
   }
   if (StripTriple || StripBitWidth) {
     Stub.Target.BitWidth.reset();
   }
   if (StripTriple) {
     Stub.Target.Triple.reset();
   }
   if (!Stub.Target.Arch && !Stub.Target.BitWidth && !Stub.Target.Endianness) {
     Stub.Target.ObjectFormat.reset();
   }
 }

 void ifs::stripIFSUndefinedSymbols(IFSStub &Stub) {
   for (auto Iter = Stub.Symbols.begin(); Iter != Stub.Symbols.end();) {
     if (Iter->Undefined) {
       Iter = Stub.Symbols.erase(Iter);
     } else {
       Iter++;
     }
   }
 }
	//===- IFSHandler.cpp -----------------------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===-----------------------------------------------------------------------===/

	#include "llvm/InterfaceStub/IFSHandler.h"
	#include "llvm/ADT/StringRef.h"
	#include "llvm/ADT/StringSwitch.h"
	#include "llvm/ADT/Triple.h"
	#include "llvm/BinaryFormat/ELF.h"
	#include "llvm/InterfaceStub/IFSStub.h"
	#include "llvm/Support/Error.h"
	#include "llvm/Support/LineIterator.h"
	#include "llvm/Support/YAMLTraits.h"

	using namespace llvm;
	using namespace llvm::ifs;

	LLVM_YAML_IS_SEQUENCE_VECTOR(IFSSymbol)

	namespace llvm {
	namespace yaml {

	/// YAML traits for ELFSymbolType.
	template <> struct ScalarEnumerationTraits<IFSSymbolType> {
	static void enumeration(IO &IO, IFSSymbolType &SymbolType) {
	IO.enumCase(SymbolType, "NoType", IFSSymbolType::NoType);
	IO.enumCase(SymbolType, "Func", IFSSymbolType::Func);
	IO.enumCase(SymbolType, "Object", IFSSymbolType::Object);
	IO.enumCase(SymbolType, "TLS", IFSSymbolType::TLS);
	IO.enumCase(SymbolType, "Unknown", IFSSymbolType::Unknown);
	// Treat other symbol types as noise, and map to Unknown.
	if (!IO.outputting() && IO.matchEnumFallback())
	SymbolType = IFSSymbolType::Unknown;
	}
	};

	template <> struct ScalarTraits<IFSEndiannessType> {
	static void output(const IFSEndiannessType &Value, void *,
	llvm::raw_ostream &Out) {
	switch (Value) {
	case IFSEndiannessType::Big:
	Out << "big";
	break;
	case IFSEndiannessType::Little:
	Out << "little";
	break;
	default:
	llvm_unreachable("Unsupported endianness");
	}
	}

	static StringRef input(StringRef Scalar, void *, IFSEndiannessType &Value) {
	Value = StringSwitch<IFSEndiannessType>(Scalar)
	.Case("big", IFSEndiannessType::Big)
	.Case("little", IFSEndiannessType::Little)
	.Default(IFSEndiannessType::Unknown);
	if (Value == IFSEndiannessType::Unknown) {
	return "Unsupported endianness";
	}
	return StringRef();
	}

	static QuotingType mustQuote(StringRef) { return QuotingType::None; }
	};

	template <> struct ScalarTraits<IFSBitWidthType> {
	static void output(const IFSBitWidthType &Value, void *,
	llvm::raw_ostream &Out) {
	switch (Value) {
	case IFSBitWidthType::IFS32:
	Out << "32";
	break;
	case IFSBitWidthType::IFS64:
	Out << "64";
	break;
	default:
	llvm_unreachable("Unsupported bit width");
	}
	}

	static StringRef input(StringRef Scalar, void *, IFSBitWidthType &Value) {
	Value = StringSwitch<IFSBitWidthType>(Scalar)
	.Case("32", IFSBitWidthType::IFS32)
	.Case("64", IFSBitWidthType::IFS64)
	.Default(IFSBitWidthType::Unknown);
	if (Value == IFSBitWidthType::Unknown) {
	return "Unsupported bit width";
	}
	return StringRef();
	}

	static QuotingType mustQuote(StringRef) { return QuotingType::None; }
	};

	template <> struct MappingTraits<IFSTarget> {
	static void mapping(IO &IO, IFSTarget &Target) {
	IO.mapOptional("ObjectFormat", Target.ObjectFormat);
	IO.mapOptional("Arch", Target.ArchString);
	IO.mapOptional("Endianness", Target.Endianness);
	IO.mapOptional("BitWidth", Target.BitWidth);
	}

	// Compacts symbol information into a single line.
	static const bool flow = true; // NOLINT(readability-identifier-naming)
	};

	/// YAML traits for ELFSymbol.
	template <> struct MappingTraits<IFSSymbol> {
	static void mapping(IO &IO, IFSSymbol &Symbol) {
	IO.mapRequired("Name", Symbol.Name);
	IO.mapRequired("Type", Symbol.Type);
	// The need for symbol size depends on the symbol type.
	if (Symbol.Type == IFSSymbolType::NoType) {
	IO.mapOptional("Size", Symbol.Size, (uint64_t)0);
	} else if (Symbol.Type == IFSSymbolType::Func) {
	Symbol.Size = 0;
	} else {
	IO.mapRequired("Size", Symbol.Size);
	}
	IO.mapOptional("Undefined", Symbol.Undefined, false);
	IO.mapOptional("Weak", Symbol.Weak, false);
	IO.mapOptional("Warning", Symbol.Warning);
	}

	// Compacts symbol information into a single line.
	static const bool flow = true; // NOLINT(readability-identifier-naming)
	};

	/// YAML traits for ELFStub objects.
	template <> struct MappingTraits<IFSStub> {
	static void mapping(IO &IO, IFSStub &Stub) {
	if (!IO.mapTag("!ifs-v1", true))
	IO.setError("Not a .tbe YAML file.");
	IO.mapRequired("IfsVersion", Stub.IfsVersion);
	IO.mapOptional("SoName", Stub.SoName);
	IO.mapOptional("Target", Stub.Target);
	IO.mapOptional("NeededLibs", Stub.NeededLibs);
	IO.mapRequired("Symbols", Stub.Symbols);
	}
	};

	/// YAML traits for ELFStubTriple objects.
	template <> struct MappingTraits<IFSStubTriple> {
	static void mapping(IO &IO, IFSStubTriple &Stub) {
	if (!IO.mapTag("!ifs-v1", true))
	IO.setError("Not a .tbe YAML file.");
	IO.mapRequired("IfsVersion", Stub.IfsVersion);
	IO.mapOptional("SoName", Stub.SoName);
	IO.mapOptional("Target", Stub.Target.Triple);
	IO.mapOptional("NeededLibs", Stub.NeededLibs);
	IO.mapRequired("Symbols", Stub.Symbols);
	}
	};
	} // end namespace yaml
	} // end namespace llvm

	/// Attempt to determine if a Text stub uses target triple.
	bool usesTriple(StringRef Buf) {
	for (line_iterator I(MemoryBufferRef(Buf, "ELFStub")); !I.is_at_eof(); ++I) {
	StringRef Line = (*I).trim();
	if (Line.startswith("Target:")) {
	if (Line == "Target:" \|\| Line.contains("{")) {
	return false;
	}
	}
	}
	return true;
	}

	Expected<std::unique_ptr<IFSStub>> ifs::readIFSFromBuffer(StringRef Buf) {
	yaml::Input YamlIn(Buf);
	std::unique_ptr<IFSStubTriple> Stub(new IFSStubTriple());
	if (usesTriple(Buf)) {
	YamlIn >> *Stub;
	} else {
	YamlIn >> static_cast<IFSStub >(Stub.get());
	}
	if (std::error_code Err = YamlIn.error()) {
	return createStringError(Err, "YAML failed reading as IFS");
	}

	if (Stub->IfsVersion > IFSVersionCurrent)
	return make_error<StringError>(
	"IFS version " + Stub->IfsVersion.getAsString() + " is unsupported.",
	std::make_error_code(std::errc::invalid_argument));
	if (Stub->Target.ArchString) {
	Stub->Target.Arch =
	ELF::convertArchNameToEMachine(Stub->Target.ArchString.getValue());
	}
	return std::move(Stub);
	}

	Error ifs::writeIFSToOutputStream(raw_ostream &OS, const IFSStub &Stub) {
	yaml::Output YamlOut(OS, NULL, /WrapColumn =/0);
	std::unique_ptr<IFSStubTriple> CopyStub(new IFSStubTriple(Stub));
	if (Stub.Target.Arch) {
	CopyStub->Target.ArchString = std::string(
	ELF::convertEMachineToArchName(Stub.Target.Arch.getValue()));
	}
	IFSTarget Target = Stub.Target;

	if (CopyStub->Target.Triple \|\|
	(!CopyStub->Target.ArchString && !CopyStub->Target.Endianness &&
	!CopyStub->Target.BitWidth))
	YamlOut << *CopyStub;
	else
	YamlOut << static_cast<IFSStub >(CopyStub.get());
	return Error::success();
	}

	Error ifs::overrideIFSTarget(IFSStub &Stub, Optional<IFSArch> OverrideArch,
	Optional<IFSEndiannessType> OverrideEndianness,
	Optional<IFSBitWidthType> OverrideBitWidth,
	Optional<std::string> OverrideTriple) {
	std::error_code OverrideEC(1, std::generic_category());
	if (OverrideArch) {
	if (Stub.Target.Arch &&
	Stub.Target.Arch.getValue() != OverrideArch.getValue()) {
	return make_error<StringError>(
	"Supplied Arch conflicts with the text stub", OverrideEC);
	}
	Stub.Target.Arch = OverrideArch.getValue();
	}
	if (OverrideEndianness) {
	if (Stub.Target.Endianness &&
	Stub.Target.Endianness.getValue() != OverrideEndianness.getValue()) {
	return make_error<StringError>(
	"Supplied Endianness conflicts with the text stub", OverrideEC);
	}
	Stub.Target.Endianness = OverrideEndianness.getValue();
	}
	if (OverrideBitWidth) {
	if (Stub.Target.BitWidth &&
	Stub.Target.BitWidth.getValue() != OverrideBitWidth.getValue()) {
	return make_error<StringError>(
	"Supplied BitWidth conflicts with the text stub", OverrideEC);
	}
	Stub.Target.BitWidth = OverrideBitWidth.getValue();
	}
	if (OverrideTriple) {
	if (Stub.Target.Triple &&
	Stub.Target.Triple.getValue() != OverrideTriple.getValue()) {
	return make_error<StringError>(
	"Supplied Triple conflicts with the text stub", OverrideEC);
	}
	Stub.Target.Triple = OverrideTriple.getValue();
	}
	return Error::success();
	}

	Error ifs::validateIFSTarget(IFSStub &Stub, bool ParseTriple) {
	std::error_code ValidationEC(1, std::generic_category());
	if (Stub.Target.Triple) {
	if (Stub.Target.Arch \|\| Stub.Target.BitWidth \|\| Stub.Target.Endianness \|\|
	Stub.Target.ObjectFormat) {
	return make_error<StringError>(
	"Target triple cannot be used simultaneously with ELF target format",
	ValidationEC);
	}
	if (ParseTriple) {
	IFSTarget TargetFromTriple = parseTriple(Stub.Target.Triple.getValue());
	Stub.Target.Arch = TargetFromTriple.Arch;
	Stub.Target.BitWidth = TargetFromTriple.BitWidth;
	Stub.Target.Endianness = TargetFromTriple.Endianness;
	}
	return Error::success();
	}
	if (!Stub.Target.Arch \|\| !Stub.Target.BitWidth \|\| !Stub.Target.Endianness) {
	// TODO: unify the error message.
	if (!Stub.Target.Arch) {
	return make_error<StringError>("Arch is not defined in the text stub",
	ValidationEC);
	}
	if (!Stub.Target.BitWidth) {
	return make_error<StringError>("BitWidth is not defined in the text stub",
	ValidationEC);
	}
	if (!Stub.Target.Endianness) {
	return make_error<StringError>(
	"Endianness is not defined in the text stub", ValidationEC);
	}
	}
	return Error::success();
	}

	IFSTarget ifs::parseTriple(StringRef TripleStr) {
	Triple IFSTriple(TripleStr);
	IFSTarget RetTarget;
	// TODO: Implement a Triple Arch enum to e_machine map.
	switch (IFSTriple.getArch()) {
	case Triple::ArchType::aarch64:
	RetTarget.Arch = (IFSArch)ELF::EM_AARCH64;
	break;
	case Triple::ArchType::x86_64:
	RetTarget.Arch = (IFSArch)ELF::EM_X86_64;
	break;
	default:
	RetTarget.Arch = (IFSArch)ELF::EM_NONE;
	}
	RetTarget.Endianness = IFSTriple.isLittleEndian() ? IFSEndiannessType::Little
	: IFSEndiannessType::Big;
	RetTarget.BitWidth =
	IFSTriple.isArch64Bit() ? IFSBitWidthType::IFS64 : IFSBitWidthType::IFS32;
	return RetTarget;
	}

	void ifs::stripIFSTarget(IFSStub &Stub, bool StripTriple, bool StripArch,
	bool StripEndianness, bool StripBitWidth) {
	if (StripTriple \|\| StripArch) {
	Stub.Target.Arch.reset();
	Stub.Target.ArchString.reset();
	}
	if (StripTriple \|\| StripEndianness) {
	Stub.Target.Endianness.reset();
	}
	if (StripTriple \|\| StripBitWidth) {
	Stub.Target.BitWidth.reset();
	}
	if (StripTriple) {
	Stub.Target.Triple.reset();
	}
	if (!Stub.Target.Arch && !Stub.Target.BitWidth && !Stub.Target.Endianness) {
	Stub.Target.ObjectFormat.reset();
	}
	}

	void ifs::stripIFSUndefinedSymbols(IFSStub &Stub) {
	for (auto Iter = Stub.Symbols.begin(); Iter != Stub.Symbols.end();) {
	if (Iter->Undefined) {
	Iter = Stub.Symbols.erase(Iter);
	} else {
	Iter++;
	}
	}
	}