include/llvm/IR/DIBuilder.h

//===- DIBuilder.h - Debug Information Builder ------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a DIBuilder that is useful for creating debugging
// information entries in LLVM IR form.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_DIBUILDER_H
#define LLVM_IR_DIBUILDER_H

#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Support/DataTypes.h"

namespace llvm {
  class BasicBlock;
  class Instruction;
  class Function;
  class Module;
  class Value;
  class LLVMContext;
  class MDNode;
  class StringRef;
  class DIBasicType;
  class DICompileUnit;
  class DICompositeType;
  class DIDerivedType;
  class DIDescriptor;
  class DIFile;
  class DIEnumerator;
  class DIType;
  class DIArray;
  class DIGlobalVariable;
  class DIImportedEntity;
  class DINameSpace;
  class DIVariable;
  class DISubrange;
  class DILexicalBlockFile;
  class DILexicalBlock;
  class DIScope;
  class DISubprogram;
  class DITemplateTypeParameter;
  class DITemplateValueParameter;
  class DIObjCProperty;

  class DIBuilder {
    private:
    Module &M;
    LLVMContext &VMContext;

    MDNode *TempEnumTypes;
    MDNode *TempRetainTypes;
    MDNode *TempSubprograms;
    MDNode *TempGVs;
    MDNode *TempImportedModules;

    Function *DeclareFn;     // llvm.dbg.declare
    Function *ValueFn;       // llvm.dbg.value

    SmallVector<Value *, 4> AllEnumTypes;
    /// Use TrackingVH to collect RetainTypes, since they can be updated
    /// later on.
    SmallVector<TrackingVH<MDNode>, 4> AllRetainTypes;
    SmallVector<Value *, 4> AllSubprograms;
    SmallVector<Value *, 4> AllGVs;
    SmallVector<TrackingVH<MDNode>, 4> AllImportedModules;

    // Private use for multiple types of template parameters.
    DITemplateValueParameter
    createTemplateValueParameter(unsigned Tag, DIDescriptor Scope,
                                 StringRef Name, DIType Ty, Value *Val,
                                 MDNode *File = nullptr, unsigned LineNo = 0,
                                 unsigned ColumnNo = 0);

    DIBuilder(const DIBuilder &) LLVM_DELETED_FUNCTION;
    void operator=(const DIBuilder &) LLVM_DELETED_FUNCTION;

    public:
    explicit DIBuilder(Module &M);
    enum ComplexAddrKind { OpPlus=1, OpDeref };
    enum DebugEmissionKind { FullDebug=1, LineTablesOnly };

    /// finalize - Construct any deferred debug info descriptors.
    void finalize();

    /// createCompileUnit - A CompileUnit provides an anchor for all debugging
    /// information generated during this instance of compilation.
    /// @param Lang     Source programming language, eg. dwarf::DW_LANG_C99
    /// @param File     File name
    /// @param Dir      Directory
    /// @param Producer Identify the producer of debugging information and code.
    ///                 Usually this is a compiler version string.
    /// @param isOptimized A boolean flag which indicates whether optimization
    ///                    is ON or not.
    /// @param Flags    This string lists command line options. This string is
    ///                 directly embedded in debug info output which may be used
    ///                 by a tool analyzing generated debugging information.
    /// @param RV       This indicates runtime version for languages like
    ///                 Objective-C.
    /// @param SplitName The name of the file that we'll split debug info out
    ///                  into.
    /// @param Kind     The kind of debug information to generate.
    /// @param EmitDebugInfo   A boolean flag which indicates whether debug
    ///                        information should be written to the final
    ///                        output or not. When this is false, debug
    ///                        information annotations will be present in
    ///                        the IL but they are not written to the final
    ///                        assembly or object file. This supports tracking
    ///                        source location information in the back end
    ///                        without actually changing the output (e.g.,
    ///                        when using optimization remarks).
    DICompileUnit createCompileUnit(unsigned Lang, StringRef File,
                                    StringRef Dir, StringRef Producer,
                                    bool isOptimized, StringRef Flags,
                                    unsigned RV,
                                    StringRef SplitName = StringRef(),
                                    DebugEmissionKind Kind = FullDebug,
                                    bool EmitDebugInfo = true);

    /// createFile - Create a file descriptor to hold debugging information
    /// for a file.
    DIFile createFile(StringRef Filename, StringRef Directory);

    /// createEnumerator - Create a single enumerator value.
    DIEnumerator createEnumerator(StringRef Name, int64_t Val);

    /// \brief Create a DWARF unspecified type.
    DIBasicType createUnspecifiedType(StringRef Name);

    /// \brief Create C++11 nullptr type.
    DIBasicType createNullPtrType();

    /// createBasicType - Create debugging information entry for a basic
    /// type.
    /// @param Name        Type name.
    /// @param SizeInBits  Size of the type.
    /// @param AlignInBits Type alignment.
    /// @param Encoding    DWARF encoding code, e.g. dwarf::DW_ATE_float.
    DIBasicType createBasicType(StringRef Name, uint64_t SizeInBits,
                                uint64_t AlignInBits, unsigned Encoding);

    /// createQualifiedType - Create debugging information entry for a qualified
    /// type, e.g. 'const int'.
    /// @param Tag         Tag identifing type, e.g. dwarf::TAG_volatile_type
    /// @param FromTy      Base Type.
    DIDerivedType createQualifiedType(unsigned Tag, DIType FromTy);

    /// createPointerType - Create debugging information entry for a pointer.
    /// @param PointeeTy   Type pointed by this pointer.
    /// @param SizeInBits  Size.
    /// @param AlignInBits Alignment. (optional)
    /// @param Name        Pointer type name. (optional)
    DIDerivedType
    createPointerType(DIType PointeeTy, uint64_t SizeInBits,
                      uint64_t AlignInBits = 0, StringRef Name = StringRef());

    /// \brief Create debugging information entry for a pointer to member.
    /// @param PointeeTy Type pointed to by this pointer.
    /// @param Class Type for which this pointer points to members of.
    DIDerivedType createMemberPointerType(DIType PointeeTy, DIType Class);

    /// createReferenceType - Create debugging information entry for a c++
    /// style reference or rvalue reference type.
    DIDerivedType createReferenceType(unsigned Tag, DIType RTy);

    /// createTypedef - Create debugging information entry for a typedef.
    /// @param Ty          Original type.
    /// @param Name        Typedef name.
    /// @param File        File where this type is defined.
    /// @param LineNo      Line number.
    /// @param Context     The surrounding context for the typedef.
    DIDerivedType createTypedef(DIType Ty, StringRef Name, DIFile File,
                                unsigned LineNo, DIDescriptor Context);

    /// createFriend - Create debugging information entry for a 'friend'.
    DIDerivedType createFriend(DIType Ty, DIType FriendTy);

    /// createInheritance - Create debugging information entry to establish
    /// inheritance relationship between two types.
    /// @param Ty           Original type.
    /// @param BaseTy       Base type. Ty is inherits from base.
    /// @param BaseOffset   Base offset.
    /// @param Flags        Flags to describe inheritance attribute,
    ///                     e.g. private
    DIDerivedType createInheritance(DIType Ty, DIType BaseTy,
                                    uint64_t BaseOffset, unsigned Flags);

    /// createMemberType - Create debugging information entry for a member.
    /// @param Scope        Member scope.
    /// @param Name         Member name.
    /// @param File         File where this member is defined.
    /// @param LineNo       Line number.
    /// @param SizeInBits   Member size.
    /// @param AlignInBits  Member alignment.
    /// @param OffsetInBits Member offset.
    /// @param Flags        Flags to encode member attribute, e.g. private
    /// @param Ty           Parent type.
    DIDerivedType
    createMemberType(DIDescriptor Scope, StringRef Name, DIFile File,
                     unsigned LineNo, uint64_t SizeInBits, uint64_t AlignInBits,
                     uint64_t OffsetInBits, unsigned Flags, DIType Ty);

    /// createStaticMemberType - Create debugging information entry for a
    /// C++ static data member.
    /// @param Scope      Member scope.
    /// @param Name       Member name.
    /// @param File       File where this member is declared.
    /// @param LineNo     Line number.
    /// @param Ty         Type of the static member.
    /// @param Flags      Flags to encode member attribute, e.g. private.
    /// @param Val        Const initializer of the member.
    DIDerivedType
    createStaticMemberType(DIDescriptor Scope, StringRef Name,
                           DIFile File, unsigned LineNo, DIType Ty,
                           unsigned Flags, llvm::Value *Val);

    /// createObjCIVar - Create debugging information entry for Objective-C
    /// instance variable.
    /// @param Name         Member name.
    /// @param File         File where this member is defined.
    /// @param LineNo       Line number.
    /// @param SizeInBits   Member size.
    /// @param AlignInBits  Member alignment.
    /// @param OffsetInBits Member offset.
    /// @param Flags        Flags to encode member attribute, e.g. private
    /// @param Ty           Parent type.
    /// @param PropertyName Name of the Objective C property associated with
    ///                     this ivar.
    /// @param PropertyGetterName Name of the Objective C property getter
    ///                           selector.
    /// @param PropertySetterName Name of the Objective C property setter
    ///                           selector.
    /// @param PropertyAttributes Objective C property attributes.
    DIDerivedType createObjCIVar(StringRef Name, DIFile File,
                                 unsigned LineNo, uint64_t SizeInBits,
                                 uint64_t AlignInBits, uint64_t OffsetInBits,
                                 unsigned Flags, DIType Ty,
                                 StringRef PropertyName = StringRef(),
                                 StringRef PropertyGetterName = StringRef(),
                                 StringRef PropertySetterName = StringRef(),
                                 unsigned PropertyAttributes = 0);

    /// createObjCIVar - Create debugging information entry for Objective-C
    /// instance variable.
    /// @param Name         Member name.
    /// @param File         File where this member is defined.
    /// @param LineNo       Line number.
    /// @param SizeInBits   Member size.
    /// @param AlignInBits  Member alignment.
    /// @param OffsetInBits Member offset.
    /// @param Flags        Flags to encode member attribute, e.g. private
    /// @param Ty           Parent type.
    /// @param PropertyNode Property associated with this ivar.
    DIDerivedType createObjCIVar(StringRef Name, DIFile File,
                                 unsigned LineNo, uint64_t SizeInBits,
                                 uint64_t AlignInBits, uint64_t OffsetInBits,
                                 unsigned Flags, DIType Ty,
                                 MDNode *PropertyNode);

    /// createObjCProperty - Create debugging information entry for Objective-C
    /// property.
    /// @param Name         Property name.
    /// @param File         File where this property is defined.
    /// @param LineNumber   Line number.
    /// @param GetterName   Name of the Objective C property getter selector.
    /// @param SetterName   Name of the Objective C property setter selector.
    /// @param PropertyAttributes Objective C property attributes.
    /// @param Ty           Type.
    DIObjCProperty createObjCProperty(StringRef Name,
                                      DIFile File, unsigned LineNumber,
                                      StringRef GetterName,
                                      StringRef SetterName,
                                      unsigned PropertyAttributes,
                                      DIType Ty);

    /// createClassType - Create debugging information entry for a class.
    /// @param Scope        Scope in which this class is defined.
    /// @param Name         class name.
    /// @param File         File where this member is defined.
    /// @param LineNumber   Line number.
    /// @param SizeInBits   Member size.
    /// @param AlignInBits  Member alignment.
    /// @param OffsetInBits Member offset.
    /// @param Flags        Flags to encode member attribute, e.g. private
    /// @param Elements     class members.
    /// @param VTableHolder Debug info of the base class that contains vtable
    ///                     for this type. This is used in
    ///                     DW_AT_containing_type. See DWARF documentation
    ///                     for more info.
    /// @param TemplateParms Template type parameters.
    /// @param UniqueIdentifier A unique identifier for the class.
    DICompositeType createClassType(DIDescriptor Scope, StringRef Name,
                                    DIFile File, unsigned LineNumber,
                                    uint64_t SizeInBits, uint64_t AlignInBits,
                                    uint64_t OffsetInBits, unsigned Flags,
                                    DIType DerivedFrom, DIArray Elements,
                                    DIType VTableHolder = DIType(),
                                    MDNode *TemplateParms = nullptr,
                                    StringRef UniqueIdentifier = StringRef());

    /// createStructType - Create debugging information entry for a struct.
    /// @param Scope        Scope in which this struct is defined.
    /// @param Name         Struct name.
    /// @param File         File where this member is defined.
    /// @param LineNumber   Line number.
    /// @param SizeInBits   Member size.
    /// @param AlignInBits  Member alignment.
    /// @param Flags        Flags to encode member attribute, e.g. private
    /// @param Elements     Struct elements.
    /// @param RunTimeLang  Optional parameter, Objective-C runtime version.
    /// @param UniqueIdentifier A unique identifier for the struct.
    DICompositeType createStructType(DIDescriptor Scope, StringRef Name,
                                     DIFile File, unsigned LineNumber,
                                     uint64_t SizeInBits, uint64_t AlignInBits,
                                     unsigned Flags, DIType DerivedFrom,
                                     DIArray Elements, unsigned RunTimeLang = 0,
                                     DIType VTableHolder = DIType(),
                                     StringRef UniqueIdentifier = StringRef());

    /// createUnionType - Create debugging information entry for an union.
    /// @param Scope        Scope in which this union is defined.
    /// @param Name         Union name.
    /// @param File         File where this member is defined.
    /// @param LineNumber   Line number.
    /// @param SizeInBits   Member size.
    /// @param AlignInBits  Member alignment.
    /// @param Flags        Flags to encode member attribute, e.g. private
    /// @param Elements     Union elements.
    /// @param RunTimeLang  Optional parameter, Objective-C runtime version.
    /// @param UniqueIdentifier A unique identifier for the union.
    DICompositeType createUnionType(
        DIDescriptor Scope, StringRef Name, DIFile File, unsigned LineNumber,
        uint64_t SizeInBits, uint64_t AlignInBits, unsigned Flags,
        DIArray Elements, unsigned RunTimeLang = 0,
        StringRef UniqueIdentifier = StringRef());

    /// createTemplateTypeParameter - Create debugging information for template
    /// type parameter.
    /// @param Scope        Scope in which this type is defined.
    /// @param Name         Type parameter name.
    /// @param Ty           Parameter type.
    /// @param File         File where this type parameter is defined.
    /// @param LineNo       Line number.
    /// @param ColumnNo     Column Number.
    DITemplateTypeParameter
    createTemplateTypeParameter(DIDescriptor Scope, StringRef Name, DIType Ty,
                                MDNode *File = nullptr, unsigned LineNo = 0,
                                unsigned ColumnNo = 0);

    /// createTemplateValueParameter - Create debugging information for template
    /// value parameter.
    /// @param Scope        Scope in which this type is defined.
    /// @param Name         Value parameter name.
    /// @param Ty           Parameter type.
    /// @param Val          Constant parameter value.
    /// @param File         File where this type parameter is defined.
    /// @param LineNo       Line number.
    /// @param ColumnNo     Column Number.
    DITemplateValueParameter
    createTemplateValueParameter(DIDescriptor Scope, StringRef Name,
                                 DIType Ty, Value *Val, MDNode *File = nullptr,
                                 unsigned LineNo = 0, unsigned ColumnNo = 0);

    /// \brief Create debugging information for a template template parameter.
    /// @param Scope        Scope in which this type is defined.
    /// @param Name         Value parameter name.
    /// @param Ty           Parameter type.
    /// @param Val          The fully qualified name of the template.
    /// @param File         File where this type parameter is defined.
    /// @param LineNo       Line number.
    /// @param ColumnNo     Column Number.
    DITemplateValueParameter
    createTemplateTemplateParameter(DIDescriptor Scope, StringRef Name,
                                    DIType Ty, StringRef Val,
                                    MDNode *File = nullptr, unsigned LineNo = 0,
                                    unsigned ColumnNo = 0);

    /// \brief Create debugging information for a template parameter pack.
    /// @param Scope        Scope in which this type is defined.
    /// @param Name         Value parameter name.
    /// @param Ty           Parameter type.
    /// @param Val          An array of types in the pack.
    /// @param File         File where this type parameter is defined.
    /// @param LineNo       Line number.
    /// @param ColumnNo     Column Number.
    DITemplateValueParameter
    createTemplateParameterPack(DIDescriptor Scope, StringRef Name,
                                DIType Ty, DIArray Val, MDNode *File = nullptr,
                                unsigned LineNo = 0, unsigned ColumnNo = 0);

    /// createArrayType - Create debugging information entry for an array.
    /// @param Size         Array size.
    /// @param AlignInBits  Alignment.
    /// @param Ty           Element type.
    /// @param Subscripts   Subscripts.
    DICompositeType createArrayType(uint64_t Size, uint64_t AlignInBits,
                                    DIType Ty, DIArray Subscripts);

    /// createVectorType - Create debugging information entry for a vector type.
    /// @param Size         Array size.
    /// @param AlignInBits  Alignment.
    /// @param Ty           Element type.
    /// @param Subscripts   Subscripts.
    DICompositeType createVectorType(uint64_t Size, uint64_t AlignInBits,
                                     DIType Ty, DIArray Subscripts);

    /// createEnumerationType - Create debugging information entry for an
    /// enumeration.
    /// @param Scope          Scope in which this enumeration is defined.
    /// @param Name           Union name.
    /// @param File           File where this member is defined.
    /// @param LineNumber     Line number.
    /// @param SizeInBits     Member size.
    /// @param AlignInBits    Member alignment.
    /// @param Elements       Enumeration elements.
    /// @param UnderlyingType Underlying type of a C++11/ObjC fixed enum.
    /// @param UniqueIdentifier A unique identifier for the enum.
    DICompositeType createEnumerationType(DIDescriptor Scope, StringRef Name,
        DIFile File, unsigned LineNumber, uint64_t SizeInBits,
        uint64_t AlignInBits, DIArray Elements, DIType UnderlyingType,
        StringRef UniqueIdentifier = StringRef());

    /// createSubroutineType - Create subroutine type.
    /// @param File            File in which this subroutine is defined.
    /// @param ParameterTypes  An array of subroutine parameter types. This
    ///                        includes return type at 0th index.
    /// @param Flags           E.g.: LValueReference.
    ///                        These flags are used to emit dwarf attributes.
    DICompositeType createSubroutineType(DIFile File, DIArray ParameterTypes,
                                         unsigned Flags = 0);

    /// createArtificialType - Create a new DIType with "artificial" flag set.
    DIType createArtificialType(DIType Ty);

    /// createObjectPointerType - Create a new DIType with the "object pointer"
    /// flag set.
    DIType createObjectPointerType(DIType Ty);

    /// \brief Create a permanent forward-declared type.
    DICompositeType createForwardDecl(unsigned Tag, StringRef Name,
                                      DIDescriptor Scope, DIFile F,
                                      unsigned Line, unsigned RuntimeLang = 0,
                                      uint64_t SizeInBits = 0,
                                      uint64_t AlignInBits = 0,
                                      StringRef UniqueIdentifier = StringRef());

    /// \brief Create a temporary forward-declared type.
    DICompositeType createReplaceableForwardDecl(
        unsigned Tag, StringRef Name, DIDescriptor Scope, DIFile F,
        unsigned Line, unsigned RuntimeLang = 0, uint64_t SizeInBits = 0,
        uint64_t AlignInBits = 0, StringRef UniqueIdentifier = StringRef());

    /// retainType - Retain DIType in a module even if it is not referenced
    /// through debug info anchors.
    void retainType(DIType T);

    /// createUnspecifiedParameter - Create unspecified type descriptor
    /// for a subroutine type.
    DIDescriptor createUnspecifiedParameter();

    /// getOrCreateArray - Get a DIArray, create one if required.
    DIArray getOrCreateArray(ArrayRef<Value *> Elements);

    /// getOrCreateSubrange - Create a descriptor for a value range.  This
    /// implicitly uniques the values returned.
    DISubrange getOrCreateSubrange(int64_t Lo, int64_t Count);

    /// createGlobalVariable - Create a new descriptor for the specified global.
    /// @param Name        Name of the variable.
    /// @param File        File where this variable is defined.
    /// @param LineNo      Line number.
    /// @param Ty          Variable Type.
    /// @param isLocalToUnit Boolean flag indicate whether this variable is
    ///                      externally visible or not.
    /// @param Val         llvm::Value of the variable.
    DIGlobalVariable
    createGlobalVariable(StringRef Name, DIFile File, unsigned LineNo,
                         DITypeRef Ty, bool isLocalToUnit, llvm::Value *Val);

    /// \brief Create a new descriptor for the specified global.
    /// @param Name        Name of the variable.
    /// @param LinkageName Mangled variable name.
    /// @param File        File where this variable is defined.
    /// @param LineNo      Line number.
    /// @param Ty          Variable Type.
    /// @param isLocalToUnit Boolean flag indicate whether this variable is
    ///                      externally visible or not.
    /// @param Val         llvm::Value of the variable.
    DIGlobalVariable
    createGlobalVariable(StringRef Name, StringRef LinkageName, DIFile File,
                         unsigned LineNo, DITypeRef Ty, bool isLocalToUnit,
                         llvm::Value *Val);

    /// createStaticVariable - Create a new descriptor for the specified
    /// variable.
    /// @param Context     Variable scope.
    /// @param Name        Name of the variable.
    /// @param LinkageName Mangled  name of the variable.
    /// @param File        File where this variable is defined.
    /// @param LineNo      Line number.
    /// @param Ty          Variable Type.
    /// @param isLocalToUnit Boolean flag indicate whether this variable is
    ///                      externally visible or not.
    /// @param Val         llvm::Value of the variable.
    /// @param Decl        Reference to the corresponding declaration.
    DIGlobalVariable
    createStaticVariable(DIDescriptor Context, StringRef Name,
                         StringRef LinkageName, DIFile File, unsigned LineNo,
                         DITypeRef Ty, bool isLocalToUnit, llvm::Value *Val,
                         MDNode *Decl = nullptr);


    /// createLocalVariable - Create a new descriptor for the specified
    /// local variable.
    /// @param Tag         Dwarf TAG. Usually DW_TAG_auto_variable or
    ///                    DW_TAG_arg_variable.
    /// @param Scope       Variable scope.
    /// @param Name        Variable name.
    /// @param File        File where this variable is defined.
    /// @param LineNo      Line number.
    /// @param Ty          Variable Type
    /// @param AlwaysPreserve Boolean. Set to true if debug info for this
    ///                       variable should be preserved in optimized build.
    /// @param Flags       Flags, e.g. artificial variable.
    /// @param ArgNo       If this variable is an argument then this argument's
    ///                    number. 1 indicates 1st argument.
    DIVariable createLocalVariable(unsigned Tag, DIDescriptor Scope,
                                   StringRef Name,
                                   DIFile File, unsigned LineNo,
                                   DITypeRef Ty, bool AlwaysPreserve = false,
                                   unsigned Flags = 0,
                                   unsigned ArgNo = 0);


    /// createComplexVariable - Create a new descriptor for the specified
    /// variable which has a complex address expression for its address.
    /// @param Tag         Dwarf TAG. Usually DW_TAG_auto_variable or
    ///                    DW_TAG_arg_variable.
    /// @param Scope       Variable scope.
    /// @param Name        Variable name.
    /// @param F           File where this variable is defined.
    /// @param LineNo      Line number.
    /// @param Ty          Variable Type
    /// @param Addr        An array of complex address operations.
    /// @param ArgNo       If this variable is an argument then this argument's
    ///                    number. 1 indicates 1st argument.
    DIVariable createComplexVariable(unsigned Tag, DIDescriptor Scope,
                                     StringRef Name, DIFile F, unsigned LineNo,
                                     DITypeRef Ty, ArrayRef<Value *> Addr,
                                     unsigned ArgNo = 0);

    /// createFunction - Create a new descriptor for the specified subprogram.
    /// See comments in DISubprogram for descriptions of these fields.
    /// @param Scope         Function scope.
    /// @param Name          Function name.
    /// @param LinkageName   Mangled function name.
    /// @param File          File where this variable is defined.
    /// @param LineNo        Line number.
    /// @param Ty            Function type.
    /// @param isLocalToUnit True if this function is not externally visible.
    /// @param isDefinition  True if this is a function definition.
    /// @param ScopeLine     Set to the beginning of the scope this starts
    /// @param Flags         e.g. is this function prototyped or not.
    ///                      These flags are used to emit dwarf attributes.
    /// @param isOptimized   True if optimization is ON.
    /// @param Fn            llvm::Function pointer.
    /// @param TParam        Function template parameters.
    DISubprogram createFunction(DIDescriptor Scope, StringRef Name,
                                StringRef LinkageName,
                                DIFile File, unsigned LineNo,
                                DICompositeType Ty, bool isLocalToUnit,
                                bool isDefinition,
                                unsigned ScopeLine,
                                unsigned Flags = 0,
                                bool isOptimized = false,
                                Function *Fn = nullptr,
                                MDNode *TParam = nullptr,
                                MDNode *Decl = nullptr);

    /// FIXME: this is added for dragonegg. Once we update dragonegg
    /// to call resolve function, this will be removed.
    DISubprogram createFunction(DIScopeRef Scope, StringRef Name,
                                StringRef LinkageName,
                                DIFile File, unsigned LineNo,
                                DICompositeType Ty, bool isLocalToUnit,
                                bool isDefinition,
                                unsigned ScopeLine,
                                unsigned Flags = 0,
                                bool isOptimized = false,
                                Function *Fn = nullptr,
                                MDNode *TParam = nullptr,
                                MDNode *Decl = nullptr);

    /// createMethod - Create a new descriptor for the specified C++ method.
    /// See comments in DISubprogram for descriptions of these fields.
    /// @param Scope         Function scope.
    /// @param Name          Function name.
    /// @param LinkageName   Mangled function name.
    /// @param File          File where this variable is defined.
    /// @param LineNo        Line number.
    /// @param Ty            Function type.
    /// @param isLocalToUnit True if this function is not externally visible..
    /// @param isDefinition  True if this is a function definition.
    /// @param Virtuality    Attributes describing virtualness. e.g. pure
    ///                      virtual function.
    /// @param VTableIndex   Index no of this method in virtual table.
    /// @param VTableHolder  Type that holds vtable.
    /// @param Flags         e.g. is this function prototyped or not.
    ///                      This flags are used to emit dwarf attributes.
    /// @param isOptimized   True if optimization is ON.
    /// @param Fn            llvm::Function pointer.
    /// @param TParam        Function template parameters.
    DISubprogram createMethod(DIDescriptor Scope, StringRef Name,
                              StringRef LinkageName,
                              DIFile File, unsigned LineNo,
                              DICompositeType Ty, bool isLocalToUnit,
                              bool isDefinition,
                              unsigned Virtuality = 0, unsigned VTableIndex = 0,
                              DIType VTableHolder = DIType(),
                              unsigned Flags = 0,
                              bool isOptimized = false,
                              Function *Fn = nullptr,
                              MDNode *TParam = nullptr);

    /// createNameSpace - This creates new descriptor for a namespace
    /// with the specified parent scope.
    /// @param Scope       Namespace scope
    /// @param Name        Name of this namespace
    /// @param File        Source file
    /// @param LineNo      Line number
    DINameSpace createNameSpace(DIDescriptor Scope, StringRef Name,
                                DIFile File, unsigned LineNo);


    /// createLexicalBlockFile - This creates a descriptor for a lexical
    /// block with a new file attached. This merely extends the existing
    /// lexical block as it crosses a file.
    /// @param Scope       Lexical block.
    /// @param File        Source file.
    DILexicalBlockFile createLexicalBlockFile(DIDescriptor Scope,
                                              DIFile File);

    /// createLexicalBlock - This creates a descriptor for a lexical block
    /// with the specified parent context.
    /// @param Scope         Parent lexical scope.
    /// @param File          Source file.
    /// @param Line          Line number.
    /// @param Col           Column number.
    /// @param Discriminator DWARF path discriminator value.
    DILexicalBlock createLexicalBlock(DIDescriptor Scope, DIFile File,
                                      unsigned Line, unsigned Col,
                                      unsigned Discriminator);

    /// \brief Create a descriptor for an imported module.
    /// @param Context The scope this module is imported into
    /// @param NS The namespace being imported here
    /// @param Line Line number
    DIImportedEntity createImportedModule(DIScope Context, DINameSpace NS,
                                          unsigned Line);

    /// \brief Create a descriptor for an imported module.
    /// @param Context The scope this module is imported into
    /// @param NS An aliased namespace
    /// @param Line Line number
    DIImportedEntity createImportedModule(DIScope Context, DIImportedEntity NS,
                                          unsigned Line);

    /// \brief Create a descriptor for an imported function.
    /// @param Context The scope this module is imported into
    /// @param Decl The declaration (or definition) of a function, type, or
    ///             variable
    /// @param Line Line number
    DIImportedEntity createImportedDeclaration(DIScope Context, DIScope Decl,
                                               unsigned Line,
                                               StringRef Name = StringRef());
    DIImportedEntity createImportedDeclaration(DIScope Context,
                                               DIImportedEntity NS,
                                               unsigned Line,
                                               StringRef Name = StringRef());

    /// insertDeclare - Insert a new llvm.dbg.declare intrinsic call.
    /// @param Storage     llvm::Value of the variable
    /// @param VarInfo     Variable's debug info descriptor.
    /// @param InsertAtEnd Location for the new intrinsic.
    Instruction *insertDeclare(llvm::Value *Storage, DIVariable VarInfo,
                               BasicBlock *InsertAtEnd);

    /// insertDeclare - Insert a new llvm.dbg.declare intrinsic call.
    /// @param Storage      llvm::Value of the variable
    /// @param VarInfo      Variable's debug info descriptor.
    /// @param InsertBefore Location for the new intrinsic.
    Instruction *insertDeclare(llvm::Value *Storage, DIVariable VarInfo,
                               Instruction *InsertBefore);


    /// insertDbgValueIntrinsic - Insert a new llvm.dbg.value intrinsic call.
    /// @param Val          llvm::Value of the variable
    /// @param Offset       Offset
    /// @param VarInfo      Variable's debug info descriptor.
    /// @param InsertAtEnd Location for the new intrinsic.
    Instruction *insertDbgValueIntrinsic(llvm::Value *Val, uint64_t Offset,
                                         DIVariable VarInfo,
                                         BasicBlock *InsertAtEnd);

    /// insertDbgValueIntrinsic - Insert a new llvm.dbg.value intrinsic call.
    /// @param Val          llvm::Value of the variable
    /// @param Offset       Offset
    /// @param VarInfo      Variable's debug info descriptor.
    /// @param InsertBefore Location for the new intrinsic.
    Instruction *insertDbgValueIntrinsic(llvm::Value *Val, uint64_t Offset,
                                         DIVariable VarInfo,
                                         Instruction *InsertBefore);

  };
} // end namespace llvm

#endif