/*++

Copyright (c) 2024, Quinn Stephens.
Provided under the BSD 3-Clause license.

Module Name:

   ntdef.h

Abstract:

   Provides basic NT definitions.

--*/

#ifndef _NTDEF_H
#define _NTDEF_H

#include <string.h>

#ifndef IN
#define IN
#endif

#ifndef OUT
#define OUT
#endif

#ifndef OPTIONAL
#define OPTIONAL
#endif

#ifndef VOID
#define VOID void
#endif

#ifndef CONST
#define CONST const
#endif

#ifndef ANYSIZE_ARRAY
#define ANYSIZE_ARRAY 1
#endif

#ifndef NULL
#if defined(__cplusplus)
#define NULL 0
#else
#define NULL ((VOID *)0)
#endif
#endif

#ifndef FORCEINLINE
#if defined(_MSC_EXTENSIONS)
#define FORCEINLINE __forceinline
#else
#define FORCEINLINE static inline
#endif
#endif

#ifndef FASTCALL
#if defined(_M_IX86)
#define FASTCALL __fastcall
#else
#define FASTCALL
#endif
#endif

#ifndef NTAPI
#if !defined(_M_AMD64)
#define NTAPI __stdcall
#else
#define NTAPI
#endif
#endif

//
// Basic types.
//
typedef char CHAR;
typedef short SHORT;
typedef long LONG;
typedef unsigned char UCHAR;
typedef unsigned short USHORT;
typedef unsigned long ULONG;

//
// Minimum/maximum values of basic types.
//
#define MINCHAR   0x80
#define MAXCHAR   0x7f
#define MINSHORT  0x8000
#define MAXSHORT  0x7fff
#define MINLONG   0x80000000
#define MAXLONG   0x7fffffff
#define MAXUCHAR  0xff
#define MAXUSHORT 0xffff
#define MAXULONG  0xffffffff

//
// Long long types.
//
#if defined(_MSC_EXTENSIONS)
typedef __int64 LONGLONG;
typedef unsigned __int64 ULONGLONG;
#elif defined(UNIX_LP64)
typedef long LONGLONG;
typedef unsigned long ULONGLONG;
#else
typedef long long LONGLONG;
typedef unsigned long long ULONGLONG;
#endif

typedef LONGLONG *PLONGLONG;
typedef ULONGLONG *PULONGLONG;

#define MAXLONGLONG  0x7fffffffffffffff
#define MAXULONGLONG 0xffffffffffffffff

//
// Logical/boolean value types.
//
typedef ULONG LOGICAL;
typedef ULONG *PLOGICAL;
typedef int BOOL;
typedef BOOL *PBOOL;
typedef UCHAR BOOLEAN;
typedef BOOLEAN *PBOOLEAN;

#define TRUE  1
#define FALSE 0

//
// Basic pointer types.
//
typedef VOID *PVOID;
typedef CHAR *PCHAR;
typedef SHORT *PSHORT;
typedef UCHAR *PUCHAR;
typedef USHORT *PUSHORT;
typedef ULONG *PULONG;

//
// Numeric pointer types.
//
#ifdef _WIN64
typedef LONGLONG LONG_PTR;
typedef ULONGLONG ULONG_PTR;
#else
typedef LONG LONG_PTR;
typedef ULONG ULONG_PTR;
#endif

//
// String types.
//
typedef CHAR *PSTR, *LPSTR;
typedef CONST CHAR *PCSTR, *LPCSTR;

//
// Wide character/string types.
//
typedef USHORT WCHAR;
typedef WCHAR *PWCHAR, *PWSTR, *LPWSTR;
typedef CONST WCHAR *PCWSTR, *LPCWSTR;

//
// Handle types.
//
typedef PVOID HANDLE;
typedef HANDLE *PHANDLE;

#define INVALID_HANDLE_VALUE ((HANDLE)(LONG_PTR)-1)

//
// Status code types.
//
typedef LONG NTSTATUS;
typedef NTSTATUS *PNTSTATUS;

//
// Status code utilities.
//
#define NT_SUCCESS(Status)     ((NTSTATUS)(Status) >= 0)
#define NT_INFORMATION(Status) ((ULONG)(Status) >> 30 == 1)
#define NT_WARNING(Status)     ((ULONG)(Status) >> 30 == 2)
#define NT_ERROR(Status)       ((ULONG)(Status) >> 30 == 3)

//
// Struct field offset helper.
//
#if defined(__clang__) || defined(__GNUC__)
#define FIELD_OFFSET(type, field) ((ULONG)__builtin_offsetof(type, field))
#else
#define FIELD_OFFSET(type, field) ((ULONG)&(((type *)0)->field))
#endif

//
// Alignment helpers.
//
#define ALIGN_DOWN(x, a) ((x) & ~((a) - 1))
#define ALIGN_UP(x, a)   ALIGN_DOWN((x) + (a) - 1, a)

//
// Large (64-bit) integer value.
//
typedef union LARGE_INTEGER {
    struct {
        ULONG LowPart;
        LONG HighPart;
    };

    LONGLONG QuadPart;
} LARGE_INTEGER, *PLARGE_INTEGER;

//
// Large (64-bit) unsigned integer value.
//
typedef union ULARGE_INTEGER {
    struct {
        ULONG LowPart;
        ULONG HighPart;
    };

    ULONGLONG QuadPart;
} ULARGE_INTEGER, *PULARGE_INTEGER;

//
// Doubly-linked list entry.
//
typedef struct _LIST_ENTRY {
    struct _LIST_ENTRY *Flink;
    struct _LIST_ENTRY *Blink;
} LIST_ENTRY, *PLIST_ENTRY;

FORCEINLINE
VOID
InitializeListHead (
    IN PLIST_ENTRY Head
    )

/*++

Routine Description:

    Initializes a list head.

Arguments:

    Head - the list head.

Return Value:

    None.

--*/

{
    Head->Blink = Head;
    Head->Flink = Head;
}

FORCEINLINE
BOOLEAN
RemoveEntryList (
    IN PLIST_ENTRY Entry
    )

/*++

Routine Description:

    Removes a list entry from a list.

Arguments:

    Entry - the entry to remove.

Return Value:

    True if the list is now empty,
    False if the list still has at least one entry.

--*/

{
    PLIST_ENTRY Blink, Flink;

    Blink = Entry->Blink;
    Flink = Entry->Flink;
    Blink->Flink = Flink;
    Flink->Blink = Blink;

    return (BOOLEAN)(Flink == Blink);
}

//
// Unicode string.
//
typedef struct _UNICODE_STRING {
    USHORT Length;
    USHORT MaximumLength;
    PWSTR Buffer;
} UNICODE_STRING, *PUNICODE_STRING;
typedef CONST UNICODE_STRING *PCUNICODE_STRING;

#define UNICODE_NULL ((WCHAR) 0)

#define MAX_USTRING ALIGN_DOWN(MAXUSHORT, sizeof(WCHAR))

#include <guiddef.h>

#endif /* !_NTDEF_H */