zig/lib/std / coff.zig

The number that identifies the type of target machine.

const std = @import("std.zig");
const assert = std.debug.assert;
const mem = std.mem;

Header

The number of sections. This indicates the size of the section table, which immediately follows the headers.


pub const Header = extern struct {
    /// The number that identifies the type of target machine.
    machine: IMAGE.FILE.MACHINE,

Flags

The low 32 bits of the number of seconds since 00:00 January 1, 1970 (a C run-time time_t value), which indicates when the file was created.


    /// The number of sections. This indicates the size of the section table, which immediately follows the headers.
    number_of_sections: u16,

IMAGE_NT_OPTIONAL_HDR32_MAGIC

The file offset of the COFF symbol table, or zero if no COFF symbol table is present. This value should be zero for an image because COFF debugging information is deprecated.


    /// The low 32 bits of the number of seconds since 00:00 January 1, 1970 (a C run-time time_t value),
    /// which indicates when the file was created.
    time_date_stamp: u32,

IMAGE_NT_OPTIONAL_HDR64_MAGIC

The number of entries in the symbol table. This data can be used to locate the string table, which immediately follows the symbol table. This value should be zero for an image because COFF debugging information is deprecated.


    /// The file offset of the COFF symbol table, or zero if no COFF symbol table is present.
    /// This value should be zero for an image because COFF debugging information is deprecated.
    pointer_to_symbol_table: u32,

DllFlags

The size of the optional header, which is required for executable files but not for object files. This value should be zero for an object file. For a description of the header format, see Optional Header (Image Only).


    /// The number of entries in the symbol table.
    /// This data can be used to locate the string table, which immediately follows the symbol table.
    /// This value should be zero for an image because COFF debugging information is deprecated.
    number_of_symbols: u32,

Subsystem

The flags that indicate the attributes of the file.


    /// The size of the optional header, which is required for executable files but not for object files.
    /// This value should be zero for an object file. For a description of the header format, see Optional Header (Image Only).
    size_of_optional_header: u16,

OptionalHeader

Image only, Windows CE, and Microsoft Windows NT and later. This indicates that the file does not contain base relocations and must therefore be loaded at its preferred base address. If the base address is not available, the loader reports an error. The default behavior of the linker is to strip base relocations from executable (EXE) files.


    /// The flags that indicate the attributes of the file.
    flags: Header.Flags,

Magic

Image only. This indicates that the image file is valid and can be run. If this flag is not set, it indicates a linker error.


    pub const Flags = packed struct(u16) {
        /// Image only, Windows CE, and Microsoft Windows NT and later.
        /// This indicates that the file does not contain base relocations
        /// and must therefore be loaded at its preferred base address.
        /// If the base address is not available, the loader reports an error.
        /// The default behavior of the linker is to strip base relocations
        /// from executable (EXE) files.
        RELOCS_STRIPPED: bool = false,

PE32

COFF line numbers have been removed. This flag is deprecated and should be zero.


        /// Image only. This indicates that the image file is valid and can be run.
        /// If this flag is not set, it indicates a linker error.
        EXECUTABLE_IMAGE: bool = false,

@"PE32+"

COFF symbol table entries for local symbols have been removed. This flag is deprecated and should be zero.


        /// COFF line numbers have been removed. This flag is deprecated and should be zero.
        LINE_NUMS_STRIPPED: bool = false,

IMAGE_NUMBEROF_DIRECTORY_ENTRIES

Obsolete. Aggressively trim working set. This flag is deprecated for Windows 2000 and later and must be zero.


        /// COFF symbol table entries for local symbols have been removed.
        /// This flag is deprecated and should be zero.
        LOCAL_SYMS_STRIPPED: bool = false,

ImageDataDirectory

Application can handle > 2-GB addresses.


        /// Obsolete. Aggressively trim working set.
        /// This flag is deprecated for Windows 2000 and later and must be zero.
        AGGRESSIVE_WS_TRIM: bool = false,

BaseRelocationDirectoryEntry

This flag is reserved for future use.


        /// Application can handle > 2-GB addresses.
        LARGE_ADDRESS_AWARE: bool = false,

BaseRelocation

Little endian: the least significant bit (LSB) precedes the most significant bit (MSB) in memory. This flag is deprecated and should be zero.


        /// This flag is reserved for future use.
        RESERVED: bool = false,

BaseRelocationType

Machine is based on a 32-bit-word architecture.


        /// Little endian: the least significant bit (LSB) precedes the
        /// most significant bit (MSB) in memory. This flag is deprecated and should be zero.
        BYTES_REVERSED_LO: bool = false,

DebugDirectoryEntry

Debugging information is removed from the image file.


        /// Machine is based on a 32-bit-word architecture.
        @"32BIT_MACHINE": bool = false,

DebugType

If the image is on removable media, fully load it and copy it to the swap file.


        /// Debugging information is removed from the image file.
        DEBUG_STRIPPED: bool = false,

ImportDirectoryEntry

If the image is on network media, fully load it and copy it to the swap file.


        /// If the image is on removable media, fully load it and copy it to the swap file.
        REMOVABLE_RUN_FROM_SWAP: bool = false,

ImportLookupEntry32

The image file is a system file, not a user program.


        /// If the image is on network media, fully load it and copy it to the swap file.
        NET_RUN_FROM_SWAP: bool = false,

ByName

The image file is a dynamic-link library (DLL). Such files are considered executable files for almost all purposes, although they cannot be directly run.


        /// The image file is a system file, not a user program.
        SYSTEM: bool = false,

ByOrdinal

The file should be run only on a uniprocessor machine.


        /// The image file is a dynamic-link library (DLL).
        /// Such files are considered executable files for almost all purposes,
        /// although they cannot be directly run.
        DLL: bool = false,

getImportByName()

Big endian: the MSB precedes the LSB in memory. This flag is deprecated and should be zero.


        /// The file should be run only on a uniprocessor machine.
        UP_SYSTEM_ONLY: bool = false,

getImportByOrdinal()

Image can handle a high entropy 64-bit virtual address space.


        /// Big endian: the MSB precedes the LSB in memory. This flag is deprecated and should be zero.
        BYTES_REVERSED_HI: bool = false,
    };
};

ImportLookupEntry64

DLL can be relocated at load time.


// OptionalHeader.magic values
// see https://msdn.microsoft.com/en-us/library/windows/desktop/ms680339(v=vs.85).aspx
pub const IMAGE_NT_OPTIONAL_HDR32_MAGIC = @intFromEnum(OptionalHeader.Magic.PE32);
pub const IMAGE_NT_OPTIONAL_HDR64_MAGIC = @intFromEnum(OptionalHeader.Magic.@"PE32+");

ByName

Code Integrity checks are enforced.


pub const DllFlags = packed struct(u16) {
    _reserved_0: u5 = 0,

ByOrdinal

Image is NX compatible.


    /// Image can handle a high entropy 64-bit virtual address space.
    HIGH_ENTROPY_VA: bool = false,

getImportByName()

Isolation aware, but do not isolate the image.


    /// DLL can be relocated at load time.
    DYNAMIC_BASE: bool = false,

getImportByOrdinal()

Does not use structured exception (SE) handling. No SE handler may be called in this image.


    /// Code Integrity checks are enforced.
    FORCE_INTEGRITY: bool = false,

ImportHintNameEntry

Do not bind the image.


    /// Image is NX compatible.
    NX_COMPAT: bool = false,

SectionHeader

Image must execute in an AppContainer.


    /// Isolation aware, but do not isolate the image.
    NO_ISOLATION: bool = false,

getName()

A WDM driver.


    /// Does not use structured exception (SE) handling. No SE handler may be called in this image.
    NO_SEH: bool = false,

getNameOffset()

Image supports Control Flow Guard.


    /// Do not bind the image.
    NO_BIND: bool = false,

getAlignment()

Terminal Server aware.


    /// Image must execute in an AppContainer.
    APPCONTAINER: bool = false,

setAlignment()

An unknown subsystem


    /// A WDM driver.
    WDM_DRIVER: bool = false,

isCode()

Device drivers and native Windows processes


    /// Image supports Control Flow Guard.
    GUARD_CF: bool = false,

isComdat()

The Windows graphical user interface (GUI) subsystem


    /// Terminal Server aware.
    TERMINAL_SERVER_AWARE: bool = false,
};

Flags

The Windows character subsystem


pub const Subsystem = enum(u16) {
    /// An unknown subsystem
    UNKNOWN = 0,

Align

The OS/2 character subsystem


    /// Device drivers and native Windows processes
    NATIVE = 1,

toByteUnits()

The Posix character subsystem


    /// The Windows graphical user interface (GUI) subsystem
    WINDOWS_GUI = 2,

fromByteUnits()

Native Win9x driver


    /// The Windows character subsystem
    WINDOWS_CUI = 3,

Symbol

Windows CE


    /// The OS/2 character subsystem
    OS2_CUI = 5,

sizeOf()

An Extensible Firmware Interface (EFI) application


    /// The Posix character subsystem
    POSIX_CUI = 7,

getName()

An EFI driver with boot services


    /// Native Win9x driver
    NATIVE_WINDOWS = 8,

getNameOffset()

An EFI driver with run-time services


    /// Windows CE
    WINDOWS_CE_GUI = 9,

SectionNumber

An EFI ROM image


    /// An Extensible Firmware Interface (EFI) application
    EFI_APPLICATION = 10,

SymType

XBOX


    /// An EFI driver with boot services
    EFI_BOOT_SERVICE_DRIVER = 11,

BaseType

Windows boot application


    /// An EFI driver with run-time services
    EFI_RUNTIME_DRIVER = 12,

ComplexType

The image base plus the page RVA is added to each offset to create the VA where the base relocation must be applied.


    /// An EFI ROM image
    EFI_ROM = 13,

StorageClass

The total number of bytes in the base relocation block, including the Page RVA and Block Size fields and the Type/Offset fields that follow.


    /// XBOX
    XBOX = 14,

FunctionDefinition

Stored in the remaining 12 bits of the WORD, an offset from the starting address that was specified in the Page RVA field for the block. This offset specifies where the base relocation is to be applied.


    /// Windows boot application
    WINDOWS_BOOT_APPLICATION = 16,

SectionDefinition

Stored in the high 4 bits of the WORD, a value that indicates the type of base relocation to be applied.


    _,
};

FileDefinition

The base relocation is skipped. This type can be used to pad a block.


pub const OptionalHeader = extern struct {
    magic: OptionalHeader.Magic,
    major_linker_version: u8,
    minor_linker_version: u8,
    size_of_code: u32,
    size_of_initialized_data: u32,
    size_of_uninitialized_data: u32,
    address_of_entry_point: u32,
    base_of_code: u32,

getFileName()

The base relocation adds the high 16 bits of the difference to the 16-bit field at offset. The 16-bit field represents the high value of a 32-bit word.


    pub const Magic = enum(u16) {
        PE32 = 0x10b,
        @"PE32+" = 0x20b,
        _,
    };

WeakExternalDefinition

The base relocation adds the low 16 bits of the difference to the 16-bit field at offset. The 16-bit field represents the low half of a 32-bit word.


    pub const PE32 = extern struct {
        standard: OptionalHeader,
        base_of_data: u32,
        image_base: u32,
        section_alignment: u32,
        file_alignment: u32,
        major_operating_system_version: u16,
        minor_operating_system_version: u16,
        major_image_version: u16,
        minor_image_version: u16,
        major_subsystem_version: u16,
        minor_subsystem_version: u16,
        win32_version_value: u32,
        size_of_image: u32,
        size_of_headers: u32,
        checksum: u32,
        subsystem: Subsystem,
        dll_flags: DllFlags,
        size_of_stack_reserve: u32,
        size_of_stack_commit: u32,
        size_of_heap_reserve: u32,
        size_of_heap_commit: u32,
        loader_flags: u32,
        number_of_rva_and_sizes: u32,
    };

sizeOf()

The base relocation applies all 32 bits of the difference to the 32-bit field at offset.


    pub const @"PE32+" = extern struct {
        standard: OptionalHeader,
        image_base: u64,
        section_alignment: u32,
        file_alignment: u32,
        major_operating_system_version: u16,
        minor_operating_system_version: u16,
        major_image_version: u16,
        minor_image_version: u16,
        major_subsystem_version: u16,
        minor_subsystem_version: u16,
        win32_version_value: u32,
        size_of_image: u32,
        size_of_headers: u32,
        checksum: u32,
        subsystem: Subsystem,
        dll_flags: DllFlags,
        size_of_stack_reserve: u64,
        size_of_stack_commit: u64,
        size_of_heap_reserve: u64,
        size_of_heap_commit: u64,
        loader_flags: u32,
        number_of_rva_and_sizes: u32,
    };
};

WeakExternalFlag

The base relocation adds the high 16 bits of the difference to the 16-bit field at offset. The 16-bit field represents the high value of a 32-bit word. The low 16 bits of the 32-bit value are stored in the 16-bit word that follows this base relocation. This means that this base relocation occupies two slots.


pub const IMAGE_NUMBEROF_DIRECTORY_ENTRIES = 16;

ComdatSelection

When the machine type is MIPS, the base relocation applies to a MIPS jump instruction.


pub const ImageDataDirectory = extern struct {
    virtual_address: u32,
    size: u32,
};

DebugInfoDefinition

This relocation is meaningful only when the machine type is ARM or Thumb. The base relocation applies the 32-bit address of a symbol across a consecutive MOVW/MOVT instruction pair.


pub const BaseRelocationDirectoryEntry = extern struct {
    /// The image base plus the page RVA is added to each offset to create the VA where the base relocation must be applied.
    page_rva: u32,

Error

This relocation is only meaningful when the machine type is RISC-V. The base relocation applies to the high 20 bits of a 32-bit absolute address.


    /// The total number of bytes in the base relocation block, including the Page RVA and Block Size fields and the Type/Offset fields that follow.
    block_size: u32,
};

Coff

Reserved, must be zero.


pub const BaseRelocation = packed struct(u16) {
    /// Stored in the remaining 12 bits of the WORD, an offset from the starting address that was specified in the Page RVA field for the block.
    /// This offset specifies where the base relocation is to be applied.
    offset: u12,

init()

This relocation is meaningful only when the machine type is Thumb. The base relocation applies the 32-bit address of a symbol to a consecutive MOVW/MOVT instruction pair.


    /// Stored in the high 4 bits of the WORD, a value that indicates the type of base relocation to be applied.
    type: BaseRelocationType,
};

getPdbPath()

This relocation is only meaningful when the machine type is RISC-V. The base relocation applies to the low 12 bits of a 32-bit absolute address formed in RISC-V I-type instruction format.


pub const BaseRelocationType = enum(u4) {
    /// The base relocation is skipped. This type can be used to pad a block.
    ABSOLUTE = 0,

getHeader()

This relocation is only meaningful when the machine type is RISC-V. The base relocation applies to the low 12 bits of a 32-bit absolute address formed in RISC-V S-type instruction format.


    /// The base relocation adds the high 16 bits of the difference to the 16-bit field at offset. The 16-bit field represents the high value of a 32-bit word.
    HIGH = 1,

getOptionalHeader()

This relocation is only meaningful when the machine type is LoongArch 32-bit. The base relocation applies to a 32-bit absolute address formed in two consecutive instructions.


    /// The base relocation adds the low 16 bits of the difference to the 16-bit field at offset. The 16-bit field represents the low half of a 32-bit word.
    LOW = 2,

getOptionalHeader32()

This relocation is only meaningful when the machine type is LoongArch 64-bit. The base relocation applies to a 64-bit absolute address formed in four consecutive instructions.


    /// The base relocation applies all 32 bits of the difference to the 32-bit field at offset.
    HIGHLOW = 3,

getOptionalHeader64()

The relocation is only meaningful when the machine type is MIPS. The base relocation applies to a MIPS16 jump instruction.


    /// The base relocation adds the high 16 bits of the difference to the 16-bit field at offset.
    /// The 16-bit field represents the high value of a 32-bit word.
    /// The low 16 bits of the 32-bit value are stored in the 16-bit word that follows this base relocation.
    /// This means that this base relocation occupies two slots.
    HIGHADJ = 4,

getImageBase()

The base relocation applies the difference to the 64-bit field at offset.


    /// When the machine type is MIPS, the base relocation applies to a MIPS jump instruction.
    MIPS_JMPADDR = 5,

getNumberOfDataDirectories()

The RVA of the import lookup table. This table contains a name or ordinal for each import. (The name "Characteristics" is used in Winnt.h, but no longer describes this field.)


    /// This relocation is meaningful only when the machine type is ARM or Thumb.
    /// The base relocation applies the 32-bit address of a symbol across a consecutive MOVW/MOVT instruction pair.
    // ARM_MOV32 = 5,

getDataDirectories()

The stamp that is set to zero until the image is bound. After the image is bound, this field is set to the time/data stamp of the DLL.


    /// This relocation is only meaningful when the machine type is RISC-V.
    /// The base relocation applies to the high 20 bits of a 32-bit absolute address.
    // RISCV_HIGH20 = 5,

getSymtab()

The index of the first forwarder reference.


    /// Reserved, must be zero.
    RESERVED = 6,

getStrtab()

The address of an ASCII string that contains the name of the DLL. This address is relative to the image base.


    /// This relocation is meaningful only when the machine type is Thumb.
    /// The base relocation applies the 32-bit address of a symbol to a consecutive MOVW/MOVT instruction pair.
    THUMB_MOV32 = 7,

strtabRequired()

The RVA of the import address table. The contents of this table are identical to the contents of the import lookup table until the image is bound.


    /// This relocation is only meaningful when the machine type is RISC-V.
    /// The base relocation applies to the low 12 bits of a 32-bit absolute address formed in RISC-V I-type instruction format.
    // RISCV_LOW12I = 7,

getSectionHeaders()

Every name ends with a NULL byte. IF the NULL byte does not fall on 2byte boundary, the entry structure is padded to ensure 2byte alignment.


    /// This relocation is only meaningful when the machine type is RISC-V.
    /// The base relocation applies to the low 12 bits of a 32-bit absolute address formed in RISC-V S-type instruction format.
    RISCV_LOW12S = 8,

getSectionHeadersAlloc()

An index into the export name pointer table. A match is attempted first with this value. If it fails, a binary search is performed on the DLL's export name pointer table.


    /// This relocation is only meaningful when the machine type is LoongArch 32-bit.
    /// The base relocation applies to a 32-bit absolute address formed in two consecutive instructions.
    // LOONGARCH32_MARK_LA = 8,

getSectionName()

Pointer to NULL terminated ASCII name. Variable length...


    /// This relocation is only meaningful when the machine type is LoongArch 64-bit.
    /// The base relocation applies to a 64-bit absolute address formed in four consecutive instructions.
    // LOONGARCH64_MARK_LA = 8,

getSectionByName()

Applicable only to section headers in COFF objects.


    /// The relocation is only meaningful when the machine type is MIPS.
    /// The base relocation applies to a MIPS16 jump instruction.
    MIPS_JMPADDR16 = 9,

getSectionData()

The section should not be padded to the next boundary. This flag is obsolete and is replaced by .ALIGN = .@"1BYTES". This is valid only for object files.


    /// The base relocation applies the difference to the 64-bit field at offset.
    DIR64 = 10,

getSectionDataAlloc()

The section contains executable code.


    _,
};

Symtab

The section contains initialized data.


pub const DebugDirectoryEntry = extern struct {
    characteristics: u32,
    time_date_stamp: u32,
    major_version: u16,
    minor_version: u16,
    type: DebugType,
    size_of_data: u32,
    address_of_raw_data: u32,
    pointer_to_raw_data: u32,
};

len()

The section contains uninitialized data.


pub const DebugType = enum(u32) {
    UNKNOWN = 0,
    COFF = 1,
    CODEVIEW = 2,
    FPO = 3,
    MISC = 4,
    EXCEPTION = 5,
    FIXUP = 6,
    OMAP_TO_SRC = 7,
    OMAP_FROM_SRC = 8,
    BORLAND = 9,
    RESERVED10 = 10,
    VC_FEATURE = 12,
    POGO = 13,
    ILTCG = 14,
    MPX = 15,
    REPRO = 16,
    EX_DLLCHARACTERISTICS = 20,

Tag

Reserved for future use.


    _,
};

Record

The section contains comments or other information. The .drectve section has this type. This is valid for object files only.


pub const ImportDirectoryEntry = extern struct {
    /// The RVA of the import lookup table.
    /// This table contains a name or ordinal for each import.
    /// (The name "Characteristics" is used in Winnt.h, but no longer describes this field.)
    import_lookup_table_rva: u32,

at()

The section will not become part of the image. This is valid only for object files.


    /// The stamp that is set to zero until the image is bound.
    /// After the image is bound, this field is set to the time/data stamp of the DLL.
    time_date_stamp: u32,

Slice

The section contains COMDAT data. For more information, see COMDAT Sections (Object Only). This is valid only for object files.


    /// The index of the first forwarder reference.
    forwarder_chain: u32,

next()

The section contains data referenced through the global pointer (GP).


    /// The address of an ASCII string that contains the name of the DLL.
    /// This address is relative to the image base.
    name_rva: u32,

slice()

Reserved for future use.


    /// The RVA of the import address table.
    /// The contents of this table are identical to the contents of the import lookup table until the image is bound.
    import_address_table_rva: u32,
};

Strtab

Reserved for future use.


pub const ImportLookupEntry32 = struct {
    pub const ByName = packed struct(u32) {
        name_table_rva: u31,
        flag: u1 = 0,
    };

get()

The section contains extended relocations.


    pub const ByOrdinal = packed struct(u32) {
        ordinal_number: u16,
        unused: u15 = 0,
        flag: u1 = 1,
    };

ImportHeader

The section can be discarded as needed.


    const mask = 0x80000000;

ImportType

The section cannot be cached.


    pub fn getImportByName(raw: u32) ?ByName {
        if (mask & raw != 0) return null;
        return @as(ByName, @bitCast(raw));
    }

ImportNameType

The section is not pageable.


    pub fn getImportByOrdinal(raw: u32) ?ByOrdinal {
        if (mask & raw == 0) return null;
        return @as(ByOrdinal, @bitCast(raw));
    }
};

Relocation

The section can be shared in memory.


pub const ImportLookupEntry64 = struct {
    pub const ByName = packed struct(u64) {
        name_table_rva: u31,
        unused: u32 = 0,
        flag: u1 = 0,
    };

IMAGE

The section can be executed as code.


    pub const ByOrdinal = packed struct(u64) {
        ordinal_number: u16,
        unused: u47 = 0,
        flag: u1 = 1,
    };

DIRECTORY_ENTRY

The section can be read.


    const mask = 0x8000000000000000;

len

The section can be written to.


    pub fn getImportByName(raw: u64) ?ByName {
        if (mask & raw != 0) return null;
        return @as(ByName, @bitCast(raw));
    }

FILE

The symbol record is not yet assigned a section. A value of zero indicates that a reference to an external symbol is defined elsewhere. A value of non-zero is a common symbol with a size that is specified by the value.


    pub fn getImportByOrdinal(raw: u64) ?ByOrdinal {
        if (mask & raw == 0) return null;
        return @as(ByOrdinal, @bitCast(raw));
    }
};

MACHINE

The symbol has an absolute (non-relocatable) value and is not an address.


/// Every name ends with a NULL byte. IF the NULL byte does not fall on
/// 2byte boundary, the entry structure is padded to ensure 2byte alignment.
pub const ImportHintNameEntry = extern struct {
    /// An index into the export name pointer table.
    /// A match is attempted first with this value. If it fails, a binary search is performed on the DLL's export name pointer table.
    hint: u16,

AXP64:

The symbol provides general type or debugging information but does not correspond to a section. Microsoft tools use this setting along with .file records (storage class FILE).


    /// Pointer to NULL terminated ASCII name.
    /// Variable length...
    name: [1]u8,
};

REL

No type information or unknown base type. Microsoft tools use this setting


pub const SectionHeader = extern struct {
    name: [8]u8,
    virtual_size: u32,
    virtual_address: u32,
    size_of_raw_data: u32,
    pointer_to_raw_data: u32,
    pointer_to_relocations: u32,
    pointer_to_linenumbers: u32,
    number_of_relocations: u16,
    number_of_linenumbers: u16,
    flags: SectionHeader.Flags,

AMD64

No valid type; used with void pointers and functions


    pub fn getName(self: *align(1) const SectionHeader) ?[]const u8 {
        if (self.name[0] == '/') return null;
        const len = std.mem.indexOfScalar(u8, &self.name, @as(u8, 0)) orelse self.name.len;
        return self.name[0..len];
    }

ARM

A character (signed byte)


    pub fn getNameOffset(self: SectionHeader) ?u32 {
        if (self.name[0] != '/') return null;
        const len = std.mem.indexOfScalar(u8, &self.name, @as(u8, 0)) orelse self.name.len;
        const offset = std.fmt.parseInt(u32, self.name[1..len], 10) catch unreachable;
        return offset;
    }

ARM64

A 2-byte signed integer


    /// Applicable only to section headers in COFF objects.
    pub fn getAlignment(self: SectionHeader) ?u16 {
        return self.flags.ALIGN.toByteUnits();
    }

SH

A natural integer type (normally 4 bytes in Windows)


    pub fn setAlignment(self: *SectionHeader, new_alignment: u16) void {
        self.flags.ALIGN = .fromByteUnits(new_alignment);
    }

PPC

A 4-byte signed integer


    pub fn isCode(self: SectionHeader) bool {
        return self.flags.CNT_CODE;
    }

I386

A 4-byte floating-point number


    pub fn isComdat(self: SectionHeader) bool {
        return self.flags.LNK_COMDAT;
    }

IA64

An 8-byte floating-point number


    pub const Flags = packed struct(u32) {
        SCALE_INDEX: bool = false,

MIPS

A structure


        unused1: u2 = 0,

M32R

A union


        /// The section should not be padded to the next boundary.
        /// This flag is obsolete and is replaced by `.ALIGN = .@"1BYTES"`.
        /// This is valid only for object files.
        TYPE_NO_PAD: bool = false,

        unused4: u1 = 0,

        /// The section contains executable code.
        CNT_CODE: bool = false,

        /// The section contains initialized data.
        CNT_INITIALIZED_DATA: bool = false,

        /// The section contains uninitialized data.
        CNT_UNINITIALIZED_DATA: bool = false,

        /// Reserved for future use.
        LNK_OTHER: bool = false,

        /// The section contains comments or other information.
        /// The .drectve section has this type.
        /// This is valid for object files only.
        LNK_INFO: bool = false,

        unused10: u1 = 0,

        /// The section will not become part of the image.
        /// This is valid only for object files.
        LNK_REMOVE: bool = false,

        /// The section contains COMDAT data.
        /// For more information, see COMDAT Sections (Object Only).
        /// This is valid only for object files.
        LNK_COMDAT: bool = false,

        unused13: u2 = 0,

        union14: packed union {
            mask: u1,
            /// The section contains data referenced through the global pointer (GP).
            GPREL: bool,
            MEM_FARDATA: bool,
        } = .{ .mask = 0 },

        unused15: u1 = 0,

        union16: packed union {
            mask: u1,
            MEM_PURGEABLE: bool,
            MEM_16BIT: bool,
        } = .{ .mask = 0 },

        /// Reserved for future use.
        MEM_LOCKED: bool = false,

        /// Reserved for future use.
        MEM_PRELOAD: bool = false,

        ALIGN: SectionHeader.Flags.Align = .NONE,

        /// The section contains extended relocations.
        LNK_NRELOC_OVFL: bool = false,

        /// The section can be discarded as needed.
        MEM_DISCARDABLE: bool = false,

        /// The section cannot be cached.
        MEM_NOT_CACHED: bool = false,

        /// The section is not pageable.
        MEM_NOT_PAGED: bool = false,

        /// The section can be shared in memory.
        MEM_SHARED: bool = false,

        /// The section can be executed as code.
        MEM_EXECUTE: bool = false,

        /// The section can be read.
        MEM_READ: bool = false,

        /// The section can be written to.
        MEM_WRITE: bool = false,

        pub const Align = enum(u4) {
            NONE = 0,
            @"1BYTES" = 1,
            @"2BYTES" = 2,
            @"4BYTES" = 3,
            @"8BYTES" = 4,
            @"16BYTES" = 5,
            @"32BYTES" = 6,
            @"64BYTES" = 7,
            @"128BYTES" = 8,
            @"256BYTES" = 9,
            @"512BYTES" = 10,
            @"1024BYTES" = 11,
            @"2048BYTES" = 12,
            @"4096BYTES" = 13,
            @"8192BYTES" = 14,
            _,

            pub fn toByteUnits(a: Align) ?u16 {
                if (a == .NONE) return null;
                return @as(u16, 1) << (@intFromEnum(a) - 1);
            }

            pub fn fromByteUnits(n: u16) Align {
                std.debug.assert(std.math.isPowerOfTwo(n));
                return @enumFromInt(@ctz(n) + 1);
            }
        };
    };
};

pub const Symbol = struct {
    name: [8]u8,
    value: u32,
    section_number: SectionNumber,
    type: SymType,
    storage_class: StorageClass,
    number_of_aux_symbols: u8,

    pub fn sizeOf() usize {
        return 18;
    }

    pub fn getName(self: *const Symbol) ?[]const u8 {
        if (std.mem.eql(u8, self.name[0..4], "\x00\x00\x00\x00")) return null;
        const len = std.mem.indexOfScalar(u8, &self.name, @as(u8, 0)) orelse self.name.len;
        return self.name[0..len];
    }

    pub fn getNameOffset(self: Symbol) ?u32 {
        if (!std.mem.eql(u8, self.name[0..4], "\x00\x00\x00\x00")) return null;
        const offset = std.mem.readInt(u32, self.name[4..8], .little);
        return offset;
    }
};

pub const SectionNumber = enum(u16) {
    /// The symbol record is not yet assigned a section.
    /// A value of zero indicates that a reference to an external symbol is defined elsewhere.
    /// A value of non-zero is a common symbol with a size that is specified by the value.
    UNDEFINED = 0,

    /// The symbol has an absolute (non-relocatable) value and is not an address.
    ABSOLUTE = 0xffff,

    /// The symbol provides general type or debugging information but does not correspond to a section.
    /// Microsoft tools use this setting along with .file records (storage class FILE).
    DEBUG = 0xfffe,
    _,
};

pub const SymType = packed struct(u16) {
    complex_type: ComplexType,
    base_type: BaseType,
};

pub const BaseType = enum(u8) {
    /// No type information or unknown base type. Microsoft tools use this setting
    NULL = 0,

    /// No valid type; used with void pointers and functions
    VOID = 1,

    /// A character (signed byte)
    CHAR = 2,

    /// A 2-byte signed integer
    SHORT = 3,

    /// A natural integer type (normally 4 bytes in Windows)
    INT = 4,

    /// A 4-byte signed integer
    LONG = 5,

    /// A 4-byte floating-point number
    FLOAT = 6,

    /// An 8-byte floating-point number
    DOUBLE = 7,

    /// A structure
    STRUCT = 8,

    /// A union
    UNION = 9,

    /// An enumerated type
    ENUM = 10,

    /// A member of enumeration (a specified value)
    MOE = 11,

    /// A byte; unsigned 1-byte integer
    BYTE = 12,

    /// A word; unsigned 2-byte integer
    WORD = 13,

    /// An unsigned integer of natural size (normally, 4 bytes)
    UINT = 14,

    /// An unsigned 4-byte integer
    DWORD = 15,

    _,
};

pub const ComplexType = enum(u8) {
    /// No derived type; the symbol is a simple scalar variable.
    NULL = 0,

    /// The symbol is a pointer to base type.
    POINTER = 16,

    /// The symbol is a function that returns a base type.
    FUNCTION = 32,

    /// The symbol is an array of base type.
    ARRAY = 48,

    _,
};

pub const StorageClass = enum(u8) {
    /// A special symbol that represents the end of function, for debugging purposes.
    END_OF_FUNCTION = 0xff,

    /// No assigned storage class.
    NULL = 0,

    /// The automatic (stack) variable. The Value field specifies the stack frame offset.
    AUTOMATIC = 1,

    /// A value that Microsoft tools use for external symbols.
    /// The Value field indicates the size if the section number is IMAGE_SYM_UNDEFINED (0).
    /// If the section number is not zero, then the Value field specifies the offset within the section.
    EXTERNAL = 2,

    /// The offset of the symbol within the section.
    /// If the Value field is zero, then the symbol represents a section name.
    STATIC = 3,

    /// A register variable.
    /// The Value field specifies the register number.
    REGISTER = 4,

    /// A symbol that is defined externally.
    EXTERNAL_DEF = 5,

    /// A code label that is defined within the module.
    /// The Value field specifies the offset of the symbol within the section.
    LABEL = 6,

    /// A reference to a code label that is not defined.
    UNDEFINED_LABEL = 7,

    /// The structure member. The Value field specifies the n th member.
    MEMBER_OF_STRUCT = 8,

    /// A formal argument (parameter) of a function. The Value field specifies the n th argument.
    ARGUMENT = 9,

    /// The structure tag-name entry.
    STRUCT_TAG = 10,

    /// A union member. The Value field specifies the n th member.
    MEMBER_OF_UNION = 11,

    /// The Union tag-name entry.
    UNION_TAG = 12,

    /// A Typedef entry.
    TYPE_DEFINITION = 13,

    /// A static data declaration.
    UNDEFINED_STATIC = 14,

    /// An enumerated type tagname entry.
    ENUM_TAG = 15,

    /// A member of an enumeration. The Value field specifies the n th member.
    MEMBER_OF_ENUM = 16,

    /// A register parameter.
    REGISTER_PARAM = 17,

    /// A bit-field reference. The Value field specifies the n th bit in the bit field.
    BIT_FIELD = 18,

    /// A .bb (beginning of block) or .eb (end of block) record.
    /// The Value field is the relocatable address of the code location.
    BLOCK = 100,

    /// A value that Microsoft tools use for symbol records that define the extent of a function: begin function (.bf ), end function ( .ef ), and lines in function ( .lf ).
    /// For .lf records, the Value field gives the number of source lines in the function.
    /// For .ef records, the Value field gives the size of the function code.
    FUNCTION = 101,

    /// An end-of-structure entry.
    END_OF_STRUCT = 102,

    /// A value that Microsoft tools, as well as traditional COFF format, use for the source-file symbol record.
    /// The symbol is followed by auxiliary records that name the file.
    FILE = 103,

    /// A definition of a section (Microsoft tools use STATIC storage class instead).
    SECTION = 104,

    /// A weak external. For more information, see Auxiliary Format 3: Weak Externals.
    WEAK_EXTERNAL = 105,

    /// A CLR token symbol. The name is an ASCII string that consists of the hexadecimal value of the token.
    /// For more information, see CLR Token Definition (Object Only).
    CLR_TOKEN = 107,

    _,
};

pub const FunctionDefinition = struct {
    /// The symbol-table index of the corresponding .bf (begin function) symbol record.
    tag_index: u32,

    /// The size of the executable code for the function itself.
    /// If the function is in its own section, the SizeOfRawData in the section header is greater or equal to this field,
    /// depending on alignment considerations.
    total_size: u32,

    /// The file offset of the first COFF line-number entry for the function, or zero if none exists.
    pointer_to_linenumber: u32,

    /// The symbol-table index of the record for the next function.
    /// If the function is the last in the symbol table, this field is set to zero.
    pointer_to_next_function: u32,

    unused: [2]u8,
};

pub const SectionDefinition = struct {
    /// The size of section data; the same as SizeOfRawData in the section header.
    length: u32,

    /// The number of relocation entries for the section.
    number_of_relocations: u16,

    /// The number of line-number entries for the section.
    number_of_linenumbers: u16,

    /// The checksum for communal data. It is applicable if the IMAGE_SCN_LNK_COMDAT flag is set in the section header.
    checksum: u32,

    /// One-based index into the section table for the associated section. This is used when the COMDAT selection setting is 5.
    number: u16,

    /// The COMDAT selection number. This is applicable if the section is a COMDAT section.
    selection: ComdatSelection,

    unused: [3]u8,
};

pub const FileDefinition = struct {
    /// An ANSI string that gives the name of the source file.
    /// This is padded with nulls if it is less than the maximum length.
    file_name: [18]u8,

    pub fn getFileName(self: *const FileDefinition) []const u8 {
        const len = std.mem.indexOfScalar(u8, &self.file_name, @as(u8, 0)) orelse self.file_name.len;
        return self.file_name[0..len];
    }
};

pub const WeakExternalDefinition = struct {
    /// The symbol-table index of sym2, the symbol to be linked if sym1 is not found.
    tag_index: u32,

    /// A value of IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY indicates that no library search for sym1 should be performed.
    /// A value of IMAGE_WEAK_EXTERN_SEARCH_LIBRARY indicates that a library search for sym1 should be performed.
    /// A value of IMAGE_WEAK_EXTERN_SEARCH_ALIAS indicates that sym1 is an alias for sym2.
    flag: WeakExternalFlag,

    unused: [10]u8,

    pub fn sizeOf() usize {
        return 18;
    }
};

// https://github.com/tpn/winsdk-10/blob/master/Include/10.0.16299.0/km/ntimage.h
pub const WeakExternalFlag = enum(u32) {
    SEARCH_NOLIBRARY = 1,
    SEARCH_LIBRARY = 2,
    SEARCH_ALIAS = 3,
    ANTI_DEPENDENCY = 4,
    _,
};

pub const ComdatSelection = enum(u8) {
    /// Not a COMDAT section.
    NONE = 0,

    /// If this symbol is already defined, the linker issues a "multiply defined symbol" error.
    NODUPLICATES = 1,

    /// Any section that defines the same COMDAT symbol can be linked; the rest are removed.
    ANY = 2,

    /// The linker chooses an arbitrary section among the definitions for this symbol.
    /// If all definitions are not the same size, a "multiply defined symbol" error is issued.
    SAME_SIZE = 3,

    /// The linker chooses an arbitrary section among the definitions for this symbol.
    /// If all definitions do not match exactly, a "multiply defined symbol" error is issued.
    EXACT_MATCH = 4,

    /// The section is linked if a certain other COMDAT section is linked.
    /// This other section is indicated by the Number field of the auxiliary symbol record for the section definition.
    /// This setting is useful for definitions that have components in multiple sections
    /// (for example, code in one and data in another), but where all must be linked or discarded as a set.
    /// The other section this section is associated with must be a COMDAT section, which can be another
    /// associative COMDAT section. An associative COMDAT section's section association chain can't form a loop.
    /// The section association chain must eventually come to a COMDAT section that doesn't have IMAGE_COMDAT_SELECT_ASSOCIATIVE set.
    ASSOCIATIVE = 5,

    /// The linker chooses the largest definition from among all of the definitions for this symbol.
    /// If multiple definitions have this size, the choice between them is arbitrary.
    LARGEST = 6,

    _,
};

pub const DebugInfoDefinition = struct {
    unused_1: [4]u8,

    /// The actual ordinal line number (1, 2, 3, and so on) within the source file, corresponding to the .bf or .ef record.
    linenumber: u16,

    unused_2: [6]u8,

    /// The symbol-table index of the next .bf symbol record.
    /// If the function is the last in the symbol table, this field is set to zero.
    /// It is not used for .ef records.
    pointer_to_next_function: u32,

    unused_3: [2]u8,
};

pub const Error = error{
    InvalidPEMagic,
    InvalidPEHeader,
    InvalidMachine,
    MissingPEHeader,
    MissingCoffSection,
    MissingStringTable,
};

// Official documentation of the format: https://docs.microsoft.com/en-us/windows/win32/debug/pe-format
pub const Coff = struct {
    data: []const u8,
    // Set if `data` is backed by the image as loaded by the loader
    is_loaded: bool,
    is_image: bool,
    coff_header_offset: usize,

    guid: [16]u8 = undefined,
    age: u32 = undefined,

    // The lifetime of `data` must be longer than the lifetime of the returned Coff
    pub fn init(data: []const u8, is_loaded: bool) error{ EndOfStream, MissingPEHeader }!Coff {
        const pe_pointer_offset = 0x3C;
        const pe_magic = "PE\x00\x00";

        if (data.len < pe_pointer_offset + 4) return error.EndOfStream;
        const header_offset = mem.readInt(u32, data[pe_pointer_offset..][0..4], .little);
        if (data.len < header_offset + 4) return error.EndOfStream;
        const is_image = mem.eql(u8, data[header_offset..][0..4], pe_magic);

        const coff: Coff = .{
            .data = data,
            .is_image = is_image,
            .is_loaded = is_loaded,
            .coff_header_offset = o: {
                if (is_image) break :o header_offset + 4;
                break :o header_offset;
            },
        };

        // Do some basic validation upfront
        if (is_image) {
            const coff_header = coff.getHeader();
            if (coff_header.size_of_optional_header == 0) return error.MissingPEHeader;
        }

        // JK: we used to check for architecture here and throw an error if not x86 or derivative.
        // However I am willing to take a leap of faith and let aarch64 have a shot also.

        return coff;
    }

    pub fn getPdbPath(self: *Coff) !?[]const u8 {
        assert(self.is_image);

        const data_dirs = self.getDataDirectories();
        if (@intFromEnum(IMAGE.DIRECTORY_ENTRY.DEBUG) >= data_dirs.len) return null;

        const debug_dir = data_dirs[@intFromEnum(IMAGE.DIRECTORY_ENTRY.DEBUG)];
        var reader: std.Io.Reader = .fixed(self.data);

        if (self.is_loaded) {
            reader.seek = debug_dir.virtual_address;
        } else {
            // Find what section the debug_dir is in, in order to convert the RVA to a file offset
            for (self.getSectionHeaders()) |*sect| {
                if (debug_dir.virtual_address >= sect.virtual_address and debug_dir.virtual_address < sect.virtual_address + sect.virtual_size) {
                    reader.seek = sect.pointer_to_raw_data + (debug_dir.virtual_address - sect.virtual_address);
                    break;
                }
            } else return error.InvalidDebugDirectory;
        }

        // Find the correct DebugDirectoryEntry, and where its data is stored.
        // It can be in any section.
        const debug_dir_entry_count = debug_dir.size / @sizeOf(DebugDirectoryEntry);
        var i: u32 = 0;
        while (i < debug_dir_entry_count) : (i += 1) {
            const debug_dir_entry = try reader.takeStruct(DebugDirectoryEntry, .little);
            if (debug_dir_entry.type == .CODEVIEW) {
                const dir_offset = if (self.is_loaded) debug_dir_entry.address_of_raw_data else debug_dir_entry.pointer_to_raw_data;
                reader.seek = dir_offset;
                break;
            }
        } else return null;

        const code_view_signature = try reader.takeArray(4);
        // 'RSDS' indicates PDB70 format, used by lld.
        if (!mem.eql(u8, code_view_signature, "RSDS"))
            return error.InvalidPEMagic;
        try reader.readSliceAll(self.guid[0..]);
        self.age = try reader.takeInt(u32, .little);

        // Finally read the null-terminated string.
        const start = reader.seek;
        const len = std.mem.indexOfScalar(u8, self.data[start..], 0) orelse return null;
        return self.data[start .. start + len];
    }

    pub fn getHeader(self: Coff) Header {
        return @as(*align(1) const Header, @ptrCast(self.data[self.coff_header_offset..][0..@sizeOf(Header)])).*;
    }

    pub fn getOptionalHeader(self: Coff) OptionalHeader {
        assert(self.is_image);
        const offset = self.coff_header_offset + @sizeOf(Header);
        return @as(*align(1) const OptionalHeader, @ptrCast(self.data[offset..][0..@sizeOf(OptionalHeader)])).*;
    }

    pub fn getOptionalHeader32(self: Coff) OptionalHeader.PE32 {
        assert(self.is_image);
        const offset = self.coff_header_offset + @sizeOf(Header);
        return @as(*align(1) const OptionalHeader.PE32, @ptrCast(self.data[offset..][0..@sizeOf(OptionalHeader.PE32)])).*;
    }

    pub fn getOptionalHeader64(self: Coff) OptionalHeader.@"PE32+" {
        assert(self.is_image);
        const offset = self.coff_header_offset + @sizeOf(Header);
        return @as(*align(1) const OptionalHeader.@"PE32+", @ptrCast(self.data[offset..][0..@sizeOf(OptionalHeader.@"PE32+")])).*;
    }

    pub fn getImageBase(self: Coff) u64 {
        const hdr = self.getOptionalHeader();
        return switch (@intFromEnum(hdr.magic)) {
            IMAGE_NT_OPTIONAL_HDR32_MAGIC => self.getOptionalHeader32().image_base,
            IMAGE_NT_OPTIONAL_HDR64_MAGIC => self.getOptionalHeader64().image_base,
            else => unreachable, // We assume we have validated the header already
        };
    }

    pub fn getNumberOfDataDirectories(self: Coff) u32 {
        const hdr = self.getOptionalHeader();
        return switch (@intFromEnum(hdr.magic)) {
            IMAGE_NT_OPTIONAL_HDR32_MAGIC => self.getOptionalHeader32().number_of_rva_and_sizes,
            IMAGE_NT_OPTIONAL_HDR64_MAGIC => self.getOptionalHeader64().number_of_rva_and_sizes,
            else => unreachable, // We assume we have validated the header already
        };
    }

    pub fn getDataDirectories(self: *const Coff) []align(1) const ImageDataDirectory {
        const hdr = self.getOptionalHeader();
        const size: usize = switch (@intFromEnum(hdr.magic)) {
            IMAGE_NT_OPTIONAL_HDR32_MAGIC => @sizeOf(OptionalHeader.PE32),
            IMAGE_NT_OPTIONAL_HDR64_MAGIC => @sizeOf(OptionalHeader.@"PE32+"),
            else => unreachable, // We assume we have validated the header already
        };
        const offset = self.coff_header_offset + @sizeOf(Header) + size;
        return @as([*]align(1) const ImageDataDirectory, @ptrCast(self.data[offset..]))[0..self.getNumberOfDataDirectories()];
    }

    pub fn getSymtab(self: *const Coff) ?Symtab {
        const coff_header = self.getHeader();
        if (coff_header.pointer_to_symbol_table == 0) return null;

        const offset = coff_header.pointer_to_symbol_table;
        const size = coff_header.number_of_symbols * Symbol.sizeOf();
        return .{ .buffer = self.data[offset..][0..size] };
    }

    pub fn getStrtab(self: *const Coff) error{InvalidStrtabSize}!?Strtab {
        const coff_header = self.getHeader();
        if (coff_header.pointer_to_symbol_table == 0) return null;

        const offset = coff_header.pointer_to_symbol_table + Symbol.sizeOf() * coff_header.number_of_symbols;
        const size = mem.readInt(u32, self.data[offset..][0..4], .little);
        if ((offset + size) > self.data.len) return error.InvalidStrtabSize;

        return Strtab{ .buffer = self.data[offset..][0..size] };
    }

    pub fn strtabRequired(self: *const Coff) bool {
        for (self.getSectionHeaders()) |*sect_hdr| if (sect_hdr.getName() == null) return true;
        return false;
    }

    pub fn getSectionHeaders(self: *const Coff) []align(1) const SectionHeader {
        const coff_header = self.getHeader();
        const offset = self.coff_header_offset + @sizeOf(Header) + coff_header.size_of_optional_header;
        return @as([*]align(1) const SectionHeader, @ptrCast(self.data.ptr + offset))[0..coff_header.number_of_sections];
    }

    pub fn getSectionHeadersAlloc(self: *const Coff, allocator: mem.Allocator) ![]SectionHeader {
        const section_headers = self.getSectionHeaders();
        const out_buff = try allocator.alloc(SectionHeader, section_headers.len);
        for (out_buff, 0..) |*section_header, i| {
            section_header.* = section_headers[i];
        }

        return out_buff;
    }

    pub fn getSectionName(self: *const Coff, sect_hdr: *align(1) const SectionHeader) error{InvalidStrtabSize}![]const u8 {
        const name = sect_hdr.getName() orelse blk: {
            const strtab = (try self.getStrtab()).?;
            const name_offset = sect_hdr.getNameOffset().?;
            break :blk strtab.get(name_offset);
        };
        return name;
    }

    pub fn getSectionByName(self: *const Coff, comptime name: []const u8) ?*align(1) const SectionHeader {
        for (self.getSectionHeaders()) |*sect| {
            const section_name = self.getSectionName(sect) catch |e| switch (e) {
                error.InvalidStrtabSize => continue, //ignore invalid(?) strtab entries - see also GitHub issue #15238
            };
            if (mem.eql(u8, section_name, name)) {
                return sect;
            }
        }
        return null;
    }

    pub fn getSectionData(self: *const Coff, sec: *align(1) const SectionHeader) []const u8 {
        const offset = if (self.is_loaded) sec.virtual_address else sec.pointer_to_raw_data;
        return self.data[offset..][0..sec.virtual_size];
    }

    pub fn getSectionDataAlloc(self: *const Coff, sec: *align(1) const SectionHeader, allocator: mem.Allocator) ![]u8 {
        const section_data = self.getSectionData(sec);
        return allocator.dupe(u8, section_data);
    }
};

pub const Symtab = struct {
    buffer: []const u8,

    pub fn len(self: Symtab) usize {
        return @divExact(self.buffer.len, Symbol.sizeOf());
    }

    pub const Tag = enum {
        symbol,
        debug_info,
        func_def,
        weak_ext,
        file_def,
        sect_def,
    };

    pub const Record = union(Tag) {
        symbol: Symbol,
        debug_info: DebugInfoDefinition,
        func_def: FunctionDefinition,
        weak_ext: WeakExternalDefinition,
        file_def: FileDefinition,
        sect_def: SectionDefinition,
    };

    /// Lives as long as Symtab instance.
    pub fn at(self: Symtab, index: usize, tag: Tag) Record {
        const offset = index * Symbol.sizeOf();
        const raw = self.buffer[offset..][0..Symbol.sizeOf()];
        return switch (tag) {
            .symbol => .{ .symbol = asSymbol(raw) },
            .debug_info => .{ .debug_info = asDebugInfo(raw) },
            .func_def => .{ .func_def = asFuncDef(raw) },
            .weak_ext => .{ .weak_ext = asWeakExtDef(raw) },
            .file_def => .{ .file_def = asFileDef(raw) },
            .sect_def => .{ .sect_def = asSectDef(raw) },
        };
    }

    fn asSymbol(raw: []const u8) Symbol {
        return .{
            .name = raw[0..8].*,
            .value = mem.readInt(u32, raw[8..12], .little),
            .section_number = @as(SectionNumber, @enumFromInt(mem.readInt(u16, raw[12..14], .little))),
            .type = @as(SymType, @bitCast(mem.readInt(u16, raw[14..16], .little))),
            .storage_class = @as(StorageClass, @enumFromInt(raw[16])),
            .number_of_aux_symbols = raw[17],
        };
    }

    fn asDebugInfo(raw: []const u8) DebugInfoDefinition {
        return .{
            .unused_1 = raw[0..4].*,
            .linenumber = mem.readInt(u16, raw[4..6], .little),
            .unused_2 = raw[6..12].*,
            .pointer_to_next_function = mem.readInt(u32, raw[12..16], .little),
            .unused_3 = raw[16..18].*,
        };
    }

    fn asFuncDef(raw: []const u8) FunctionDefinition {
        return .{
            .tag_index = mem.readInt(u32, raw[0..4], .little),
            .total_size = mem.readInt(u32, raw[4..8], .little),
            .pointer_to_linenumber = mem.readInt(u32, raw[8..12], .little),
            .pointer_to_next_function = mem.readInt(u32, raw[12..16], .little),
            .unused = raw[16..18].*,
        };
    }

    fn asWeakExtDef(raw: []const u8) WeakExternalDefinition {
        return .{
            .tag_index = mem.readInt(u32, raw[0..4], .little),
            .flag = @as(WeakExternalFlag, @enumFromInt(mem.readInt(u32, raw[4..8], .little))),
            .unused = raw[8..18].*,
        };
    }

    fn asFileDef(raw: []const u8) FileDefinition {
        return .{
            .file_name = raw[0..18].*,
        };
    }

    fn asSectDef(raw: []const u8) SectionDefinition {
        return .{
            .length = mem.readInt(u32, raw[0..4], .little),
            .number_of_relocations = mem.readInt(u16, raw[4..6], .little),
            .number_of_linenumbers = mem.readInt(u16, raw[6..8], .little),
            .checksum = mem.readInt(u32, raw[8..12], .little),
            .number = mem.readInt(u16, raw[12..14], .little),
            .selection = @as(ComdatSelection, @enumFromInt(raw[14])),
            .unused = raw[15..18].*,
        };
    }

    pub const Slice = struct {
        buffer: []const u8,
        num: usize,
        count: usize = 0,

        /// Lives as long as Symtab instance.
        pub fn next(self: *Slice) ?Symbol {
            if (self.count >= self.num) return null;
            const sym = asSymbol(self.buffer[0..Symbol.sizeOf()]);
            self.count += 1;
            self.buffer = self.buffer[Symbol.sizeOf()..];
            return sym;
        }
    };

    pub fn slice(self: Symtab, start: usize, end: ?usize) Slice {
        const offset = start * Symbol.sizeOf();
        const llen = if (end) |e| e * Symbol.sizeOf() else self.buffer.len;
        const num = @divExact(llen - offset, Symbol.sizeOf());
        return Slice{ .buffer = self.buffer[offset..][0..llen], .num = num };
    }
};

pub const Strtab = struct {
    buffer: []const u8,

    pub fn get(self: Strtab, off: u32) []const u8 {
        assert(off < self.buffer.len);
        return mem.sliceTo(@as([*:0]const u8, @ptrCast(self.buffer.ptr + off)), 0);
    }
};

pub const ImportHeader = extern struct {
    /// Must be IMAGE_FILE_MACHINE_UNKNOWN
    sig1: IMAGE.FILE.MACHINE = .UNKNOWN,
    /// Must be 0xFFFF
    sig2: u16 = 0xFFFF,
    version: u16,
    machine: IMAGE.FILE.MACHINE,
    time_date_stamp: u32,
    size_of_data: u32,
    hint: u16,
    types: packed struct(u16) {
        type: ImportType,
        name_type: ImportNameType,
        reserved: u11,
    },
};

pub const ImportType = enum(u2) {
    /// Executable code.
    CODE = 0,
    /// Data.
    DATA = 1,
    /// Specified as CONST in .def file.
    CONST = 2,
    _,
};

pub const ImportNameType = enum(u3) {
    /// The import is by ordinal. This indicates that the value in the Ordinal/Hint
    /// field of the import header is the import's ordinal. If this constant is not
    /// specified, then the Ordinal/Hint field should always be interpreted as the import's hint.
    ORDINAL = 0,
    /// The import name is identical to the public symbol name.
    NAME = 1,
    /// The import name is the public symbol name, but skipping the leading ?, @, or optionally _.
    NAME_NOPREFIX = 2,
    /// The import name is the public symbol name, but skipping the leading ?, @, or optionally _,
    /// and truncating at the first @.
    NAME_UNDECORATE = 3,
    /// https://github.com/llvm/llvm-project/pull/83211
    NAME_EXPORTAS = 4,
    _,
};

pub const Relocation = extern struct {
    virtual_address: u32,
    symbol_table_index: u32,
    type: u16,
};

pub const IMAGE = struct {
    pub const DIRECTORY_ENTRY = enum(u32) {
        /// Export Directory
        EXPORT = 0,
        /// Import Directory
        IMPORT = 1,
        /// Resource Directory
        RESOURCE = 2,
        /// Exception Directory
        EXCEPTION = 3,
        /// Security Directory
        SECURITY = 4,
        /// Base Relocation Table
        BASERELOC = 5,
        /// Debug Directory
        DEBUG = 6,
        /// Architecture Specific Data
        ARCHITECTURE = 7,
        /// RVA of GP
        GLOBALPTR = 8,
        /// TLS Directory
        TLS = 9,
        /// Load Configuration Directory
        LOAD_CONFIG = 10,
        /// Bound Import Directory in headers
        BOUND_IMPORT = 11,
        /// Import Address Table
        IAT = 12,
        /// Delay Load Import Descriptors
        DELAY_IMPORT = 13,
        /// COM Runtime descriptor
        COM_DESCRIPTOR = 14,
        /// must be zero
        RESERVED = 15,
        _,

        pub const len = @typeInfo(IMAGE.DIRECTORY_ENTRY).@"enum".fields.len;
    };

    pub const FILE = struct {
        /// Machine Types
        /// The Machine field has one of the following values, which specify the CPU type.
        /// An image file can be run only on the specified machine or on a system that emulates the specified machine.
        pub const MACHINE = enum(u16) {
            /// The content of this field is assumed to be applicable to any machine type
            UNKNOWN = 0x0,
            /// Alpha AXP, 32-bit address space
            ALPHA = 0x184,
            /// Alpha 64, 64-bit address space
            ALPHA64 = 0x284,
            /// Matsushita AM33
            AM33 = 0x1d3,
            /// x64
            AMD64 = 0x8664,
            /// ARM little endian
            ARM = 0x1c0,
            /// ARM64 little endian
            ARM64 = 0xaa64,
            /// ABI that enables interoperability between native ARM64 and emulated x64 code.
            ARM64EC = 0xA641,
            /// Binary format that allows both native ARM64 and ARM64EC code to coexist in the same file.
            ARM64X = 0xA64E,
            /// ARM Thumb-2 little endian
            ARMNT = 0x1c4,
            /// EFI byte code
            EBC = 0xebc,
            /// Intel 386 or later processors and compatible processors
            I386 = 0x14c,
            /// Intel Itanium processor family
            IA64 = 0x200,
            /// LoongArch 32-bit processor family
            LOONGARCH32 = 0x6232,
            /// LoongArch 64-bit processor family
            LOONGARCH64 = 0x6264,
            /// Mitsubishi M32R little endian
            M32R = 0x9041,
            /// MIPS16
            MIPS16 = 0x266,
            /// MIPS with FPU
            MIPSFPU = 0x366,
            /// MIPS16 with FPU
            MIPSFPU16 = 0x466,
            /// Power PC little endian
            POWERPC = 0x1f0,
            /// Power PC with floating point support
            POWERPCFP = 0x1f1,
            /// MIPS I compatible 32-bit big endian
            R3000BE = 0x160,
            /// MIPS I compatible 32-bit little endian
            R3000 = 0x162,
            /// MIPS III compatible 64-bit little endian
            R4000 = 0x166,
            /// MIPS IV compatible 64-bit little endian
            R10000 = 0x168,
            /// RISC-V 32-bit address space
            RISCV32 = 0x5032,
            /// RISC-V 64-bit address space
            RISCV64 = 0x5064,
            /// RISC-V 128-bit address space
            RISCV128 = 0x5128,
            /// Hitachi SH3
            SH3 = 0x1a2,
            /// Hitachi SH3 DSP
            SH3DSP = 0x1a3,
            /// Hitachi SH4
            SH4 = 0x1a6,
            /// Hitachi SH5
            SH5 = 0x1a8,
            /// Thumb
            THUMB = 0x1c2,
            /// MIPS little-endian WCE v2
            WCEMIPSV2 = 0x169,
            _,
            /// AXP 64 (Same as Alpha 64)
            pub const AXP64: IMAGE.FILE.MACHINE = .ALPHA64;
        };
    };

    pub const REL = struct {
        /// x64 Processors
        /// The following relocation type indicators are defined for x64 and compatible processors.
        pub const AMD64 = enum(u16) {
            /// The relocation is ignored.
            ABSOLUTE = 0x0000,
            /// The 64-bit VA of the relocation target.
            ADDR64 = 0x0001,
            /// The 32-bit VA of the relocation target.
            ADDR32 = 0x0002,
            /// The 32-bit address without an image base (RVA).
            ADDR32NB = 0x0003,
            /// The 32-bit relative address from the byte following the relocation.
            REL32 = 0x0004,
            /// The 32-bit address relative to byte distance 1 from the relocation.
            REL32_1 = 0x0005,
            /// The 32-bit address relative to byte distance 2 from the relocation.
            REL32_2 = 0x0006,
            /// The 32-bit address relative to byte distance 3 from the relocation.
            REL32_3 = 0x0007,
            /// The 32-bit address relative to byte distance 4 from the relocation.
            REL32_4 = 0x0008,
            /// The 32-bit address relative to byte distance 5 from the relocation.
            REL32_5 = 0x0009,
            /// The 16-bit section index of the section that contains the target.
            /// This is used to support debugging information.
            SECTION = 0x000A,
            /// The 32-bit offset of the target from the beginning of its section.
            /// This is used to support debugging information and static thread local storage.
            SECREL = 0x000B,
            /// A 7-bit unsigned offset from the base of the section that contains the target.
            SECREL7 = 0x000C,
            /// CLR tokens.
            TOKEN = 0x000D,
            /// A 32-bit signed span-dependent value emitted into the object.
            SREL32 = 0x000E,
            /// A pair that must immediately follow every span-dependent value.
            PAIR = 0x000F,
            /// A 32-bit signed span-dependent value that is applied at link time.
            SSPAN32 = 0x0010,
            _,
        };

        /// ARM Processors
        /// The following relocation type indicators are defined for ARM processors.
        pub const ARM = enum(u16) {
            /// The relocation is ignored.
            ABSOLUTE = 0x0000,
            /// The 32-bit VA of the target.
            ADDR32 = 0x0001,
            /// The 32-bit RVA of the target.
            ADDR32NB = 0x0002,
            /// The 24-bit relative displacement to the target.
            BRANCH24 = 0x0003,
            /// The reference to a subroutine call.
            /// The reference consists of two 16-bit instructions with 11-bit offsets.
            BRANCH11 = 0x0004,
            /// The 32-bit relative address from the byte following the relocation.
            REL32 = 0x000A,
            /// The 16-bit section index of the section that contains the target.
            /// This is used to support debugging information.
            SECTION = 0x000E,
            /// The 32-bit offset of the target from the beginning of its section.
            /// This is used to support debugging information and static thread local storage.
            SECREL = 0x000F,
            /// The 32-bit VA of the target.
            /// This relocation is applied using a MOVW instruction for the low 16 bits followed by a MOVT for the high 16 bits.
            MOV32 = 0x0010,
            /// The 32-bit VA of the target.
            /// This relocation is applied using a MOVW instruction for the low 16 bits followed by a MOVT for the high 16 bits.
            THUMB_MOV32 = 0x0011,
            /// The instruction is fixed up with the 21-bit relative displacement to the 2-byte aligned target.
            /// The least significant bit of the displacement is always zero and is not stored.
            /// This relocation corresponds to a Thumb-2 32-bit conditional B instruction.
            THUMB_BRANCH20 = 0x0012,
            Unused = 0x0013,
            /// The instruction is fixed up with the 25-bit relative displacement to the 2-byte aligned target.
            /// The least significant bit of the displacement is zero and is not stored.This relocation corresponds to a Thumb-2 B instruction.
            THUMB_BRANCH24 = 0x0014,
            /// The instruction is fixed up with the 25-bit relative displacement to the 4-byte aligned target.
            /// The low 2 bits of the displacement are zero and are not stored.
            /// This relocation corresponds to a Thumb-2 BLX instruction.
            THUMB_BLX23 = 0x0015,
            /// The relocation is valid only when it immediately follows a ARM_REFHI or THUMB_REFHI.
            /// Its SymbolTableIndex contains a displacement and not an index into the symbol table.
            PAIR = 0x0016,
            _,
        };

        /// ARM64 Processors
        /// The following relocation type indicators are defined for ARM64 processors.
        pub const ARM64 = enum(u16) {
            /// The relocation is ignored.
            ABSOLUTE = 0x0000,
            /// The 32-bit VA of the target.
            ADDR32 = 0x0001,
            /// The 32-bit RVA of the target.
            ADDR32NB = 0x0002,
            /// The 26-bit relative displacement to the target, for B and BL instructions.
            BRANCH26 = 0x0003,
            /// The page base of the target, for ADRP instruction.
            PAGEBASE_REL21 = 0x0004,
            /// The 12-bit relative displacement to the target, for instruction ADR
            REL21 = 0x0005,
            /// The 12-bit page offset of the target, for instructions ADD/ADDS (immediate) with zero shift.
            PAGEOFFSET_12A = 0x0006,
            /// The 12-bit page offset of the target, for instruction LDR (indexed, unsigned immediate).
            PAGEOFFSET_12L = 0x0007,
            /// The 32-bit offset of the target from the beginning of its section.
            /// This is used to support debugging information and static thread local storage.
            SECREL = 0x0008,
            /// Bit 0:11 of section offset of the target, for instructions ADD/ADDS (immediate) with zero shift.
            SECREL_LOW12A = 0x0009,
            /// Bit 12:23 of section offset of the target, for instructions ADD/ADDS (immediate) with zero shift.
            SECREL_HIGH12A = 0x000A,
            /// Bit 0:11 of section offset of the target, for instruction LDR (indexed, unsigned immediate).
            SECREL_LOW12L = 0x000B,
            /// CLR token.
            TOKEN = 0x000C,
            /// The 16-bit section index of the section that contains the target.
            /// This is used to support debugging information.
            SECTION = 0x000D,
            /// The 64-bit VA of the relocation target.
            ADDR64 = 0x000E,
            /// The 19-bit offset to the relocation target, for conditional B instruction.
            BRANCH19 = 0x000F,
            /// The 14-bit offset to the relocation target, for instructions TBZ and TBNZ.
            BRANCH14 = 0x0010,
            /// The 32-bit relative address from the byte following the relocation.
            REL32 = 0x0011,
            _,
        };

        /// Hitachi SuperH Processors
        /// The following relocation type indicators are defined for SH3 and SH4 processors.
        /// SH5-specific relocations are noted as SHM (SH Media).
        pub const SH = enum(u16) {
            /// The relocation is ignored.
            @"3_ABSOLUTE" = 0x0000,
            /// A reference to the 16-bit location that contains the VA of the target symbol.
            @"3_DIRECT16" = 0x0001,
            /// The 32-bit VA of the target symbol.
            @"3_DIRECT32" = 0x0002,
            /// A reference to the 8-bit location that contains the VA of the target symbol.
            @"3_DIRECT8" = 0x0003,
            /// A reference to the 8-bit instruction that contains the effective 16-bit VA of the target symbol.
            @"3_DIRECT8_WORD" = 0x0004,
            /// A reference to the 8-bit instruction that contains the effective 32-bit VA of the target symbol.
            @"3_DIRECT8_LONG" = 0x0005,
            /// A reference to the 8-bit location whose low 4 bits contain the VA of the target symbol.
            @"3_DIRECT4" = 0x0006,
            /// A reference to the 8-bit instruction whose low 4 bits contain the effective 16-bit VA of the target symbol.
            @"3_DIRECT4_WORD" = 0x0007,
            /// A reference to the 8-bit instruction whose low 4 bits contain the effective 32-bit VA of the target symbol.
            @"3_DIRECT4_LONG" = 0x0008,
            /// A reference to the 8-bit instruction that contains the effective 16-bit relative offset of the target symbol.
            @"3_PCREL8_WORD" = 0x0009,
            /// A reference to the 8-bit instruction that contains the effective 32-bit relative offset of the target symbol.
            @"3_PCREL8_LONG" = 0x000A,
            /// A reference to the 16-bit instruction whose low 12 bits contain the effective 16-bit relative offset of the target symbol.
            @"3_PCREL12_WORD" = 0x000B,
            /// A reference to a 32-bit location that is the VA of the section that contains the target symbol.
            @"3_STARTOF_SECTION" = 0x000C,
            /// A reference to the 32-bit location that is the size of the section that contains the target symbol.
            @"3_SIZEOF_SECTION" = 0x000D,
            /// The 16-bit section index of the section that contains the target.
            /// This is used to support debugging information.
            @"3_SECTION" = 0x000E,
            /// The 32-bit offset of the target from the beginning of its section.
            /// This is used to support debugging information and static thread local storage.
            @"3_SECREL" = 0x000F,
            /// The 32-bit RVA of the target symbol.
            @"3_DIRECT32_NB" = 0x0010,
            /// GP relative.
            @"3_GPREL4_LONG" = 0x0011,
            /// CLR token.
            @"3_TOKEN" = 0x0012,
            /// The offset from the current instruction in longwords.
            /// If the NOMODE bit is not set, insert the inverse of the low bit at bit 32 to select PTA or PTB.
            M_PCRELPT = 0x0013,
            /// The low 16 bits of the 32-bit address.
            M_REFLO = 0x0014,
            /// The high 16 bits of the 32-bit address.
            M_REFHALF = 0x0015,
            /// The low 16 bits of the relative address.
            M_RELLO = 0x0016,
            /// The high 16 bits of the relative address.
            M_RELHALF = 0x0017,
            /// The relocation is valid only when it immediately follows a REFHALF, RELHALF, or RELLO relocation.
            /// The SymbolTableIndex field of the relocation contains a displacement and not an index into the symbol table.
            M_PAIR = 0x0018,
            /// The relocation ignores section mode.
            M_NOMODE = 0x8000,
            _,
        };

        /// IBM PowerPC Processors
        /// The following relocation type indicators are defined for PowerPC processors.
        pub const PPC = enum(u16) {
            /// The relocation is ignored.
            ABSOLUTE = 0x0000,
            /// The 64-bit VA of the target.
            ADDR64 = 0x0001,
            /// The 32-bit VA of the target.
            ADDR32 = 0x0002,
            /// The low 24 bits of the VA of the target.
            /// This is valid only when the target symbol is absolute and can be sign-extended to its original value.
            ADDR24 = 0x0003,
            /// The low 16 bits of the target's VA.
            ADDR16 = 0x0004,
            /// The low 14 bits of the target's VA.
            /// This is valid only when the target symbol is absolute and can be sign-extended to its original value.
            ADDR14 = 0x0005,
            /// A 24-bit PC-relative offset to the symbol's location.
            REL24 = 0x0006,
            /// A 14-bit PC-relative offset to the symbol's location.
            REL14 = 0x0007,
            /// The 32-bit RVA of the target.
            ADDR32NB = 0x000A,
            /// The 32-bit offset of the target from the beginning of its section.
            /// This is used to support debugging information and static thread local storage.
            SECREL = 0x000B,
            /// The 16-bit section index of the section that contains the target.
            /// This is used to support debugging information.
            SECTION = 0x000C,
            /// The 16-bit offset of the target from the beginning of its section.
            /// This is used to support debugging information and static thread local storage.
            SECREL16 = 0x000F,
            /// The high 16 bits of the target's 32-bit VA.
            /// This is used for the first instruction in a two-instruction sequence that loads a full address.
            /// This relocation must be immediately followed by a PAIR relocation whose SymbolTableIndex contains a signed 16-bit displacement that is added to the upper 16 bits that was taken from the location that is being relocated.
            REFHI = 0x0010,
            /// The low 16 bits of the target's VA.
            REFLO = 0x0011,
            /// A relocation that is valid only when it immediately follows a REFHI or SECRELHI relocation.
            /// Its SymbolTableIndex contains a displacement and not an index into the symbol table.
            PAIR = 0x0012,
            /// The low 16 bits of the 32-bit offset of the target from the beginning of its section.
            SECRELLO = 0x0013,
            /// The 16-bit signed displacement of the target relative to the GP register.
            GPREL = 0x0015,
            /// The CLR token.
            TOKEN = 0x0016,
            _,
        };

        /// Intel 386 Processors
        /// The following relocation type indicators are defined for Intel 386 and compatible processors.
        pub const I386 = enum(u16) {
            /// The relocation is ignored.
            ABSOLUTE = 0x0000,
            /// Not supported.
            DIR16 = 0x0001,
            /// Not supported.
            REL16 = 0x0002,
            /// The target's 32-bit VA.
            DIR32 = 0x0006,
            /// The target's 32-bit RVA.
            DIR32NB = 0x0007,
            /// Not supported.
            SEG12 = 0x0009,
            /// The 16-bit section index of the section that contains the target.
            /// This is used to support debugging information.
            SECTION = 0x000A,
            /// The 32-bit offset of the target from the beginning of its section.
            /// This is used to support debugging information and static thread local storage.
            SECREL = 0x000B,
            /// The CLR token.
            TOKEN = 0x000C,
            /// A 7-bit offset from the base of the section that contains the target.
            SECREL7 = 0x000D,
            /// The 32-bit relative displacement to the target.
            /// This supports the x86 relative branch and call instructions.
            REL32 = 0x0014,
            _,
        };

        /// Intel Itanium Processor Family (IPF)
        /// The following relocation type indicators are defined for the Intel Itanium processor family and compatible processors.
        /// Note that relocations on instructions use the bundle's offset and slot number for the relocation offset.
        pub const IA64 = enum(u16) {
            /// The relocation is ignored.
            ABSOLUTE = 0x0000,
            /// The instruction relocation can be followed by an ADDEND relocation whose value is added to the target address before it is inserted into the specified slot in the IMM14 bundle.
            /// The relocation target must be absolute or the image must be fixed.
            IMM14 = 0x0001,
            /// The instruction relocation can be followed by an ADDEND relocation whose value is added to the target address before it is inserted into the specified slot in the IMM22 bundle.
            /// The relocation target must be absolute or the image must be fixed.
            IMM22 = 0x0002,
            /// The slot number of this relocation must be one (1).
            /// The relocation can be followed by an ADDEND relocation whose value is added to the target address before it is stored in all three slots of the IMM64 bundle.
            IMM64 = 0x0003,
            /// The target's 32-bit VA.
            /// This is supported only for /LARGEADDRESSAWARE:NO images.
            DIR32 = 0x0004,
            /// The target's 64-bit VA.
            DIR64 = 0x0005,
            /// The instruction is fixed up with the 25-bit relative displacement to the 16-bit aligned target.
            /// The low 4 bits of the displacement are zero and are not stored.
            PCREL21B = 0x0006,
            /// The instruction is fixed up with the 25-bit relative displacement to the 16-bit aligned target.
            /// The low 4 bits of the displacement, which are zero, are not stored.
            PCREL21M = 0x0007,
            /// The LSBs of this relocation's offset must contain the slot number whereas the rest is the bundle address.
            /// The bundle is fixed up with the 25-bit relative displacement to the 16-bit aligned target.
            /// The low 4 bits of the displacement are zero and are not stored.
            PCREL21F = 0x0008,
            /// The instruction relocation can be followed by an ADDEND relocation whose value is added to the target address and then a 22-bit GP-relative offset that is calculated and applied to the GPREL22 bundle.
            GPREL22 = 0x0009,
            /// The instruction is fixed up with the 22-bit GP-relative offset to the target symbol's literal table entry.
            /// The linker creates this literal table entry based on this relocation and the ADDEND relocation that might follow.
            LTOFF22 = 0x000A,
            /// The 16-bit section index of the section contains the target.
            /// This is used to support debugging information.
            SECTION = 0x000B,
            /// The instruction is fixed up with the 22-bit offset of the target from the beginning of its section.
            /// This relocation can be followed immediately by an ADDEND relocation, whose Value field contains the 32-bit unsigned offset of the target from the beginning of the section.
            SECREL22 = 0x000C,
            /// The slot number for this relocation must be one (1).
            /// The instruction is fixed up with the 64-bit offset of the target from the beginning of its section.
            /// This relocation can be followed immediately by an ADDEND relocation whose Value field contains the 32-bit unsigned offset of the target from the beginning of the section.
            SECREL64I = 0x000D,
            /// The address of data to be fixed up with the 32-bit offset of the target from the beginning of its section.
            SECREL32 = 0x000E,
            /// The target's 32-bit RVA.
            DIR32NB = 0x0010,
            /// This is applied to a signed 14-bit immediate that contains the difference between two relocatable targets.
            /// This is a declarative field for the linker that indicates that the compiler has already emitted this value.
            SREL14 = 0x0011,
            /// This is applied to a signed 22-bit immediate that contains the difference between two relocatable targets.
            /// This is a declarative field for the linker that indicates that the compiler has already emitted this value.
            SREL22 = 0x0012,
            /// This is applied to a signed 32-bit immediate that contains the difference between two relocatable values.
            /// This is a declarative field for the linker that indicates that the compiler has already emitted this value.
            SREL32 = 0x0013,
            /// This is applied to an unsigned 32-bit immediate that contains the difference between two relocatable values.
            /// This is a declarative field for the linker that indicates that the compiler has already emitted this value.
            UREL32 = 0x0014,
            /// A 60-bit PC-relative fixup that always stays as a BRL instruction of an MLX bundle.
            PCREL60X = 0x0015,
            /// A 60-bit PC-relative fixup.
            /// If the target displacement fits in a signed 25-bit field, convert the entire bundle to an MBB bundle with NOP.B in slot 1 and a 25-bit BR instruction (with the 4 lowest bits all zero and dropped) in slot 2.
            PCREL60B = 0x0016,
            /// A 60-bit PC-relative fixup.
            /// If the target displacement fits in a signed 25-bit field, convert the entire bundle to an MFB bundle with NOP.F in slot 1 and a 25-bit (4 lowest bits all zero and dropped) BR instruction in slot 2.
            PCREL60F = 0x0017,
            /// A 60-bit PC-relative fixup.
            /// If the target displacement fits in a signed 25-bit field, convert the entire bundle to an MIB bundle with NOP.I in slot 1 and a 25-bit (4 lowest bits all zero and dropped) BR instruction in slot 2.
            PCREL60I = 0x0018,
            /// A 60-bit PC-relative fixup.
            /// If the target displacement fits in a signed 25-bit field, convert the entire bundle to an MMB bundle with NOP.M in slot 1 and a 25-bit (4 lowest bits all zero and dropped) BR instruction in slot 2.
            PCREL60M = 0x0019,
            /// A 64-bit GP-relative fixup.
            IMMGPREL64 = 0x001a,
            /// A CLR token.
            TOKEN = 0x001b,
            /// A 32-bit GP-relative fixup.
            GPREL32 = 0x001c,
            /// The relocation is valid only when it immediately follows one of the following relocations: IMM14, IMM22, IMM64, GPREL22, LTOFF22, LTOFF64, SECREL22, SECREL64I, or SECREL32.
            /// Its value contains the addend to apply to instructions within a bundle, not for data.
            ADDEND = 0x001F,
            _,
        };

        /// MIPS Processors
        /// The following relocation type indicators are defined for MIPS processors.
        pub const MIPS = enum(u16) {
            /// The relocation is ignored.
            ABSOLUTE = 0x0000,
            /// The high 16 bits of the target's 32-bit VA.
            REFHALF = 0x0001,
            /// The target's 32-bit VA.
            REFWORD = 0x0002,
            /// The low 26 bits of the target's VA.
            /// This supports the MIPS J and JAL instructions.
            JMPADDR = 0x0003,
            /// The high 16 bits of the target's 32-bit VA.
            /// This is used for the first instruction in a two-instruction sequence that loads a full address.
            /// This relocation must be immediately followed by a PAIR relocation whose SymbolTableIndex contains a signed 16-bit displacement that is added to the upper 16 bits that are taken from the location that is being relocated.
            REFHI = 0x0004,
            /// The low 16 bits of the target's VA.
            REFLO = 0x0005,
            /// A 16-bit signed displacement of the target relative to the GP register.
            GPREL = 0x0006,
            /// The same as IMAGE_REL_MIPS_GPREL.
            LITERAL = 0x0007,
            /// The 16-bit section index of the section contains the target.
            /// This is used to support debugging information.
            SECTION = 0x000A,
            /// The 32-bit offset of the target from the beginning of its section.
            /// This is used to support debugging information and static thread local storage.
            SECREL = 0x000B,
            /// The low 16 bits of the 32-bit offset of the target from the beginning of its section.
            SECRELLO = 0x000C,
            /// The high 16 bits of the 32-bit offset of the target from the beginning of its section.
            /// An IMAGE_REL_MIPS_PAIR relocation must immediately follow this one.
            /// The SymbolTableIndex of the PAIR relocation contains a signed 16-bit displacement that is added to the upper 16 bits that are taken from the location that is being relocated.
            SECRELHI = 0x000D,
            /// The low 26 bits of the target's VA.
            /// This supports the MIPS16 JAL instruction.
            JMPADDR16 = 0x0010,
            /// The target's 32-bit RVA.
            REFWORDNB = 0x0022,
            /// The relocation is valid only when it immediately follows a REFHI or SECRELHI relocation.
            /// Its SymbolTableIndex contains a displacement and not an index into the symbol table.
            PAIR = 0x0025,
            _,
        };

        /// Mitsubishi M32R
        /// The following relocation type indicators are defined for the Mitsubishi M32R processors.
        pub const M32R = enum(u16) {
            /// The relocation is ignored.
            ABSOLUTE = 0x0000,
            /// The target's 32-bit VA.
            ADDR32 = 0x0001,
            /// The target's 32-bit RVA.
            ADDR32NB = 0x0002,
            /// The target's 24-bit VA.
            ADDR24 = 0x0003,
            /// The target's 16-bit offset from the GP register.
            GPREL16 = 0x0004,
            /// The target's 24-bit offset from the program counter (PC), shifted left by 2 bits and sign-extended
            PCREL24 = 0x0005,
            /// The target's 16-bit offset from the PC, shifted left by 2 bits and sign-extended
            PCREL16 = 0x0006,
            /// The target's 8-bit offset from the PC, shifted left by 2 bits and sign-extended
            PCREL8 = 0x0007,
            /// The 16 MSBs of the target VA.
            REFHALF = 0x0008,
            /// The 16 MSBs of the target VA, adjusted for LSB sign extension.
            /// This is used for the first instruction in a two-instruction sequence that loads a full 32-bit address.
            /// This relocation must be immediately followed by a PAIR relocation whose SymbolTableIndex contains a signed 16-bit displacement that is added to the upper 16 bits that are taken from the location that is being relocated.
            REFHI = 0x0009,
            /// The 16 LSBs of the target VA.
            REFLO = 0x000A,
            /// The relocation must follow the REFHI relocation.
            /// Its SymbolTableIndex contains a displacement and not an index into the symbol table.
            PAIR = 0x000B,
            /// The 16-bit section index of the section that contains the target.
            /// This is used to support debugging information.
            SECTION = 0x000C,
            /// The 32-bit offset of the target from the beginning of its section.
            /// This is used to support debugging information and static thread local storage.
            SECREL = 0x000D,
            /// The CLR token.
            TOKEN = 0x000E,
            _,
        };
    };
};