////////////////////////////////
// Context Cracking

// untangle compiler, os, & architecture
#if defined(__clang__)
# define COMPILER_CLANG 1

# if defined(_WIN32)
#  define OS_WINDOWS 1
# elif defined(__gnu_linux__)
#  define OS_LINUX 1
# elif defined(__APPLE__) && defined(__MACH__)
#  define OS_MAC 1
# else
#  error missing OS detection
# endif

# if defined(__amd64__)
#  define ARCH_X64 1
// TODO(allen): verify this works on clang
# elif defined(__i386__)
#  define ARCH_X86 1
// TODO(allen): verify this works on clang
# elif defined(__arm__)
#  define ARCH_ARM 1
// TODO(allen): verify this works on clang
# elif defined(__aarch64__)
#  define ARCH_ARM64 1
# else
#  error missing ARCH detection
# endif

#elif defined(_MSC_VER)
# define COMPILER_CL 1

# if defined(_WIN32)
#  define OS_WINDOWS 1
# else
#  error missing OS detection
# endif

# if defined(_M_AMD64)
#  define ARCH_X64 1
# elif defined(_M_I86)
#  define ARCH_X86 1
# elif defined(_M_ARM)
#  define ARCH_ARM 1
// TODO(allen): ARM64?
# else
#  error missing ARCH detection
# endif

#elif defined(__GNUC__)
# define COMPILER_GCC 1

# if defined(_WIN32)
#  define OS_WINDOWS 1
# elif defined(__gnu_linux__)
#  define OS_LINUX 1
# elif defined(__APPLE__) && defined(__MACH__)
#  define OS_MAC 1
# else
#  error missing OS detection
# endif

# if defined(__amd64__)
#  define ARCH_X64 1
# elif defined(__i386__)
#  define ARCH_X86 1
# elif defined(__arm__)
#  define ARCH_ARM 1
# elif defined(__aarch64__)
#  define ARCH_ARM64 1
# else
#  error missing ARCH detection
# endif

#else
# error no context cracking for this compiler
#endif

#if !defined(COMPILER_CL)
# define COMPILER_CL 0
#endif
#if !defined(COMPILER_CLANG)
# define COMPILER_CLANG 0
#endif
#if !defined(COMPILER_GCC)
# define COMPILER_GCC 0
#endif
#if !defined(OS_WINDOWS)
# define OS_WINDOWS 0
#endif
#if !defined(OS_LINUX)
# define OS_LINUX 0
#endif
#if !defined(OS_MAC)
# define OS_MAC 0
#endif
#if !defined(ARCH_X64)
# define ARCH_X64 0
#endif
#if !defined(ARCH_X86)
# define ARCH_X86 0
#endif
#if !defined(ARCH_ARM)
# define ARCH_ARM 0
#endif
#if !defined(ARCH_ARM64)
# define ARCH_ARM64 0
#endif


// language
#if defined(__cplusplus)
# define LANG_CXX 1
#else
# define LANG_C 1
#endif

#if !defined(LANG_CXX)
# define LANG_CXX 0
#endif
#if !defined(LANG_C)
# define LANG_C 0
#endif


////////////////////////////////
// GLUE(a,b) STRIFY(s)

#define GLUE__(a,b) a##b
#define GLUE_(a,b)  GLUE__(a,b)
#define GLUE(a,b)   GLUE_(a,b)

#define STRIFY__(s) #s
#define STRIFY_(s)  STRIFY__(s)
#define STRIFY(s)   STRIFY_(s)


////////////////////////////////
// SECTION(<section-name>) <Decl>

#if COMPILER_CLANG || COMPILER_GCC
# define SECTION(N) __attribute__((__section__(N)))
#elif COMPILER_CL
# define SECTION(N) __declspec(allocate(N))
#else
# error SECTION not defined for this compiler
#endif

// for CL users: #pragma section(<section>,read,write)


////////////////////////////////
// BEFORE_MAIN(){ <...> }

#if OS_WINDOWS

# pragma section(".CRT$XCU", read)

# if LANG_CXX

#  define BEFORE_MAIN_NAMED(n)                 \
static void n(void);                          \
__declspec(allocate(".CRT$XCU"))              \
__pragma(comment(linker,"/include:" #n "__")) \
extern "C" void (*n##__)(void);               \
void (*n##__)(void) = n;                      \
static void n(void)

# else

#  define BEFORE_MAIN_NAMED(n)                 \
static void n(void);                          \
__declspec(allocate(".CRT$XCU"))              \
__pragma(comment(linker,"/include:" #n "__")) \
void (*n##__)(void) = n;                      \
static void n(void)

# endif

#elif OS_LINUX

# define BEFORE_MAIN_NAMED(n) \
__attribute__((constructor)) static void n(void)

#else
# error BEFORE_MAIN missing for this OS
#endif

#define BEFORE_MAIN_(n) BEFORE_MAIN_NAMED(n)
#define BEFORE_MAIN()   BEFORE_MAIN_(GLUE(beforemain,__COUNTER__))


////////////////////////////////
// DO_NOT_ELIMINATE

#if OS_WINDOWS
# define DO_NOT_ELIMINATE__S0(N) __pragma(comment(linker,"/include:" #N))
# define DO_NOT_ELIMINATE__S1(N) DO_NOT_ELIMINATE__S0(N)
# define DO_NOT_ELIMINATE(N)     DO_NOT_ELIMINATE__S1(N)
#else

# define DO_NOT_ELIMINATE(N)

#endif


////////////////////////////////
// Types

#include <stdint.h>

typedef int8_t   S8;
typedef int16_t  S16;
typedef int32_t  S32;
typedef int64_t  S64;
typedef uint8_t  U8;
typedef uint16_t U16;
typedef uint32_t U32;
typedef uint64_t U64;
typedef S8  B8;
typedef S16 B16;
typedef S32 B32;
typedef S64 B64;
typedef float  F32;
typedef double F64;

typedef struct RangePtr{
  U8 *first;
  U8 *opl;
} RangePtr;

typedef struct String8{
  U8 *str;
  U64 size;
} String8;

#define str8_lit(str) str8((U8*)(str), sizeof(str) - 1)
#define str8_lit_const(str) { (U8*)(str), sizeof(str) - 1 }
#define str8_expand(s) ((int)((s).size)), ((s).str)

////////////////////////////////
// Functions

static String8  str8(U8 *str, U64 size);
static B32      str8_match(String8 a, String8 b, U32 flags);

static void* os_this_image(void);

static RangePtr self_img_get_section(void *image, String8 name);