/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
 *               2018, 2019
 *   Jonathan Schleifer <js@heap.zone>
 *
 * All rights reserved.
 *
 * This file is part of ObjFW. It may be distributed under the terms of the
 * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
 * the packaging of this file.
 *
 * Alternatively, it may be distributed under the terms of the GNU General
 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"

#import "ObjFWRT.h"
#import "private.h"

#include <exec/libraries.h>
#include <exec/nodes.h>
#include <exec/resident.h>
#include <proto/exec.h>

#define CONCAT_VERSION2(major, minor) #major "." #minor
#define CONCAT_VERSION(major, minor) CONCAT_VERSION2(major, minor)
#define VERSION_STRING CONCAT_VERSION(OBJFWRT_LIB_MAJOR, OBJFWRT_LIB_MINOR)

#if defined(OF_AMIGAOS_M68K)
# define DATA_OFFSET 0x7FFE
#elif defined(OF_MORPHOS)
# define DATA_OFFSET 0x8000
#endif

#ifdef OF_AMIGAOS_M68K
# define OBJC_M68K_REG(reg) __asm__(#reg)
#else
# define OBJC_M68K_REG(reg)
#endif

/* This always needs to be the first thing in the file. */
int
_start()
{
	return -1;
}

struct ObjFWRTBase {
	struct Library library;
	void *segList;
	struct ObjFWRTBase *parent;
	char *dataSeg;
	bool initialized;
};

#ifdef OF_AMIGAOS_M68K
extern uintptr_t __CTOR_LIST__[];
extern const void *_EH_FRAME_BEGINS__;
extern void *_EH_FRAME_OBJECTS__;
#endif

extern bool objc_init_m68k(void);
extern void __objc_exec_class_m68k(void);
extern IMP _Nonnull objc_msg_lookup_m68k(void);
extern IMP _Nonnull objc_msg_lookup_stret_m68k(void);
extern IMP _Nonnull objc_msg_lookup_super_m68k(void);
extern IMP _Nonnull objc_msg_lookup_super_stret_m68k(void);
extern Class _Nullable objc_lookUpClass_m68k(void);
extern Class _Nullable objc_getClass_m68k(void);
extern Class _Nonnull objc_getRequiredClass_m68k(void);
extern Class _Nullable objc_lookup_class_m68k(void);
extern Class _Nonnull objc_get_class_m68k(void);
extern void objc_exception_throw_m68k(void);
extern int objc_sync_enter_m68k(void);
extern int objc_sync_exit_m68k(void);
extern id _Nullable objc_getProperty_m68k(void);
extern void objc_setProperty_m68k(void);
extern void objc_getPropertyStruct_m68k(void);
extern void objc_setPropertyStruct_m68k(void);
extern void objc_enumerationMutation_m68k(void);
extern int __gnu_objc_personality_sj0_m68k(void);
extern int __gnu_objc_personality_v0_m68k(void);
extern id _Nullable objc_retain_m68k(void);
extern id _Nullable objc_retainBlock_m68k(void);
extern id _Nullable objc_retainAutorelease_m68k(void);
extern void objc_release_m68k(void);
extern id _Nullable objc_autorelease_m68k(void);
extern id _Nullable objc_autoreleaseReturnValue_m68k(void);
extern id _Nullable objc_retainAutoreleaseReturnValue_m68k(void);
extern id _Nullable objc_retainAutoreleasedReturnValue_m68k(void);
extern id _Nullable objc_storeStrong_m68k(void);
extern id _Nullable objc_storeWeak_m68k(void);
extern id _Nullable objc_loadWeakRetained_m68k(void);
extern id _Nullable objc_initWeak_m68k(void);
extern void objc_destroyWeak_m68k(void);
extern id _Nullable objc_loadWeak_m68k(void);
extern void objc_copyWeak_m68k(void);
extern void objc_moveWeak_m68k(void);
extern SEL _Nonnull sel_registerName_m68k(void);
extern const char *_Nonnull sel_getName_m68k(void);
extern bool sel_isEqual_m68k(void);
extern Class _Nonnull objc_allocateClassPair_m68k(void);
extern void objc_registerClassPair_m68k(void);
extern unsigned int objc_getClassList_m68k(void);
extern Class _Nonnull *_Nonnull objc_copyClassList_m68k(void);
extern bool class_isMetaClass_m68k(void);
extern const char *_Nullable class_getName_m68k(void);
extern Class _Nullable class_getSuperclass_m68k(void);
extern unsigned long class_getInstanceSize_m68k(void);
extern bool class_respondsToSelector_m68k(void);
extern bool class_conformsToProtocol_m68k(void);
extern IMP _Nullable class_getMethodImplementation_m68k(void);
extern IMP _Nullable class_getMethodImplementation_stret_m68k(void);
extern const char *_Nullable class_getMethodTypeEncoding_m68k(void);
extern bool class_addMethod_m68k(void);
extern IMP _Nullable class_replaceMethod_m68k(void);
extern Class _Nullable object_getClass_m68k(void);
extern Class _Nullable object_setClass_m68k(void);
extern const char *_Nullable object_getClassName_m68k(void);
extern const char *_Nonnull protocol_getName_m68k(void);
extern bool protocol_isEqual_m68k(void);
extern bool protocol_conformsToProtocol_m68k(void);
extern void objc_exit_m68k(void);
extern _Nullable objc_uncaught_exception_handler_t
    objc_setUncaughtExceptionHandler_m68k(void);
extern void objc_setForwardHandler_m68k(void);
extern void objc_setEnumerationMutationHandler_m68k(void);
extern void objc_zero_weak_references_m68k(void);

#ifdef OF_MORPHOS
const ULONG __abox__ = 1;
#endif
struct ExecBase *SysBase;
struct objc_libc libc;
FILE *stdout;
FILE *stderr;

#if defined(OF_AMIGAOS_M68K)
__asm__ (
    ".text\n"
    ".globl ___restore_a4\n"
    ".align 1\n"
    "___restore_a4:\n"
    "	movea.l	42(a6), a4\n"
    "	rts"
);
#elif defined(OF_MORPHOS)
__asm__ (
    ".section .text\n"
    ".globl __restore_r13\n"
    ".align 2\n"
    "__restore_r13:\n"
    "	lwz	%r13, 56(%r2)\n"
    "	lwz	%r13, 44(%r13)\n"
    "	blr\n"
    ".type __restore_r13, @function\n"
    ".size __restore_r13, .-__restore_r13"
);
#endif

static OF_INLINE char *
getDataSeg(void)
{
	char *dataSeg;

#if defined(OF_AMIGAOS_M68K)
	__asm__ (
	    "move.l	#___a4_init, %0"
	    : "=r"(dataSeg)
	);
#elif defined(OF_MORPHOS)
	__asm__ (
	    "lis	%0, __r13_init@ha\n\t"
	    "la		%0, __r13_init@l(%0)"
	    : "=r"(dataSeg)
	);
#endif

	return dataSeg;
}

static OF_INLINE size_t
getDataSize(void)
{
	size_t dataSize;

#if defined(OF_AMIGAOS_M68K)
	__asm__ (
	    "move.l	#___data_size, %0"
	    : "=r"(dataSize)
	);
#elif defined(OF_MORPHOS)
	__asm__ (
	    "lis	%0, __sdata_size@ha\n\t"
	    "la		%0, __sdata_size@l(%0)\n\t"
	    "lis	%%r9, __sbss_size@ha\n\t"
	    "la		%%r9, __sbss_size@l(%%r9)\n\t"
	    "add	%0, %0, %%r9"
	    : "=r"(dataSize)
	    :: "r9"
	);
#endif

	return dataSize;
}

static OF_INLINE size_t *
getDataDataRelocs(void)
{
	size_t *dataDataRelocs;

#if defined(OF_AMIGAOS_M68K)
	__asm__ (
	    "move.l	#___datadata_relocs, %0"
	    : "=r"(dataDataRelocs)
	);
#elif defined(OF_MORPHOS)
	__asm__ (
	    "lis	%0, __datadata_relocs@ha\n\t"
	    "la		%0, __datadata_relocs@l(%0)\n\t"
	    : "=r"(dataDataRelocs)
	);
#endif

	return dataDataRelocs;
}

static struct Library *
lib_init(struct ObjFWRTBase *base OBJC_M68K_REG(d0),
    void *segList OBJC_M68K_REG(a0), struct ExecBase *sysBase OBJC_M68K_REG(a6))
{
#if defined(OF_AMIGAOS_M68K)
	__asm__ __volatile__ (
	    "move.l	a6, _SysBase"
	    :: "a"(sysBase)
	);
#elif defined(OF_MORPHOS)
	__asm__ __volatile__ (
	    "lis	%%r9, SysBase@ha\n\t"
	    "stw	%0, SysBase@l(%%r9)"
	    :: "r"(sysBase) : "r9"
	);
#endif

	base->segList = segList;
	base->parent = NULL;
	base->dataSeg = getDataSeg();

	return &base->library;
}

struct Library *__saveds
lib_open(void)
{
	OBJC_M68K_ARG(struct ObjFWRTBase *, base, a6)

	struct ObjFWRTBase *child;
	size_t dataSize, *dataDataRelocs;
	ptrdiff_t displacement;

	if (base->parent != NULL)
		return NULL;

	base->library.lib_OpenCnt++;
	base->library.lib_Flags &= ~LIBF_DELEXP;

	/*
	 * We cannot use malloc here, as that depends on the libc passed from
	 * the application.
	 */
	if ((child = AllocMem(base->library.lib_NegSize +
	    base->library.lib_PosSize, MEMF_ANY)) == NULL) {
		base->library.lib_OpenCnt--;
		return NULL;
	}

	memcpy(child, (char *)base - base->library.lib_NegSize,
	    base->library.lib_NegSize + base->library.lib_PosSize);

	child = (struct ObjFWRTBase *)
	    ((char *)child + base->library.lib_NegSize);
	child->library.lib_OpenCnt = 1;
	child->parent = base;

	dataSize = getDataSize();

	if ((child->dataSeg = AllocMem(dataSize, MEMF_ANY)) == NULL) {
		FreeMem((char *)child - child->library.lib_NegSize,
		    child->library.lib_NegSize + child->library.lib_PosSize);
		base->library.lib_OpenCnt--;
		return NULL;
	}

	memcpy(child->dataSeg, base->dataSeg - DATA_OFFSET, dataSize);

	dataDataRelocs = getDataDataRelocs();
	displacement = child->dataSeg - (base->dataSeg - DATA_OFFSET);

	for (size_t i = 1; i <= dataDataRelocs[0]; i++)
		*(long *)(child->dataSeg + dataDataRelocs[i]) += displacement;

	child->dataSeg += DATA_OFFSET;

	return &child->library;
}

static void *
expunge(struct ObjFWRTBase *base)
{
	void *segList;

	if (base->parent != NULL) {
		base->parent->library.lib_Flags |= LIBF_DELEXP;
		return 0;
	}

	if (base->library.lib_OpenCnt > 0) {
		base->library.lib_Flags |= LIBF_DELEXP;
		return 0;
	}

	segList = base->segList;

	Remove(&base->library.lib_Node);
	FreeMem((char *)base - base->library.lib_NegSize,
	    base->library.lib_NegSize + base->library.lib_PosSize);

	return segList;
}

static void *__saveds
lib_expunge(void)
{
	OBJC_M68K_ARG(struct ObjFWRTBase *, base, a6)

	return expunge(base);
}

static void *__saveds
lib_close(void)
{
	OBJC_M68K_ARG(struct ObjFWRTBase *, base, a6)

	if (base->parent != NULL) {
		struct ObjFWRTBase *parent;

#ifdef OF_AMIGAOS_M68K
		if (base->initialized)
			for (size_t i = 1; i <= (size_t)_EH_FRAME_BEGINS__; i++)
				libc.__deregister_frame_info(
				    (&_EH_FRAME_BEGINS__)[i]);
#endif

		parent = base->parent;

		FreeMem(base->dataSeg - DATA_OFFSET, getDataSize());
		FreeMem((char *)base - base->library.lib_NegSize,
		    base->library.lib_NegSize + base->library.lib_PosSize);

		base = parent;
	}

	if (--base->library.lib_OpenCnt == 0 &&
	    (base->library.lib_Flags & LIBF_DELEXP))
		return expunge(base);

	return NULL;
}

static void *
lib_null(void)
{
	return NULL;
}

bool
objc_init(void)
{
	OBJC_M68K_ARG(struct ObjFWRTBase *, base, a6)
	OBJC_M68K_ARG(unsigned int, version, d0)
	OBJC_M68K_ARG(struct objc_libc *, libc_, a0)
	OBJC_M68K_ARG(FILE *, stdout_, a1)
	OBJC_M68K_ARG(FILE *, stderr_, a2)

	uintptr_t *iter, *iter0;

	if (version > 1)
		return false;

	memcpy(&libc, libc_, sizeof(libc));
	stdout = stdout_;
	stderr = stderr_;

#ifdef OF_AMIGAOS_M68K
	if ((size_t)_EH_FRAME_BEGINS__ != (size_t)_EH_FRAME_OBJECTS__)
		return false;

	for (size_t i = 1; i <= (size_t)_EH_FRAME_BEGINS__; i++)
		libc.__register_frame_info((&_EH_FRAME_BEGINS__)[i],
		    (&_EH_FRAME_OBJECTS__)[i]);

	iter0 = &__CTOR_LIST__[1];
#elif defined(OF_MORPHOS)
	__asm__ (
	    "lis	%0, ctors+4@ha\n\t"
	    "la		%0, ctors+4@l(%0)\n\t"
	    : "=r"(iter0)
	);
#endif

	for (iter = iter0; *iter != 0; iter++);

	while (iter > iter0) {
		void (*ctor)(void) = (void (*)(void))*--iter;
		ctor();
	}

	base->initialized = true;

	return true;
}

void *
malloc(size_t size)
{
	return libc.malloc(size);
}

void *
calloc(size_t count, size_t size)
{
	return libc.calloc(count, size);
}

void *
realloc(void *ptr, size_t size)
{
	return libc.realloc(ptr, size);
}

void
free(void *ptr)
{
	libc.free(ptr);
}

int
fprintf(FILE *restrict stream, const char *restrict fmt, ...)
{
	int ret;
	va_list args;

	va_start(args, fmt);
	ret = libc.vfprintf(stream, fmt, args);
	va_end(args);

	return ret;
}

int
fflush(FILE *restrict stream)
{
	return libc.fflush(stream);
}

void
abort(void)
{
	libc.abort();

	OF_UNREACHABLE
}

#ifdef HAVE_SJLJ_EXCEPTIONS
int
_Unwind_SjLj_RaiseException(void *ex)
{
	return libc._Unwind_SjLj_RaiseException(ex);
}
#else
int
_Unwind_RaiseException(void *ex)
{
	return libc._Unwind_RaiseException(ex);
}
#endif

void
_Unwind_DeleteException(void *ex)
{
	libc._Unwind_DeleteException(ex);
}

void *
_Unwind_GetLanguageSpecificData(void *ctx)
{
	return libc._Unwind_GetLanguageSpecificData(ctx);
}

uintptr_t
_Unwind_GetRegionStart(void *ctx)
{
	return libc._Unwind_GetRegionStart(ctx);
}

uintptr_t
_Unwind_GetDataRelBase(void *ctx)
{
	return libc._Unwind_GetDataRelBase(ctx);
}

uintptr_t
_Unwind_GetTextRelBase(void *ctx)
{
	return libc._Unwind_GetTextRelBase(ctx);
}

uintptr_t
_Unwind_GetIP(void *ctx)
{
	return libc._Unwind_GetIP(ctx);
}

uintptr_t
_Unwind_GetGR(void *ctx, int gr)
{
	return libc._Unwind_GetGR(ctx, gr);
}

void
_Unwind_SetIP(void *ctx, uintptr_t ip)
{
	libc._Unwind_SetIP(ctx, ip);
}

void
_Unwind_SetGR(void *ctx, int gr, uintptr_t value)
{
	libc._Unwind_SetGR(ctx, gr, value);
}

#ifdef HAVE_SJLJ_EXCEPTIONS
void
_Unwind_SjLj_Resume(void *ex)
{
	libc._Unwind_SjLj_Resume(ex);
}
#else
void
_Unwind_Resume(void *ex)
{
	libc._Unwind_Resume(ex);
}
#endif

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic"
static CONST_APTR functionTable[] = {
#ifdef OF_MORPHOS
	(CONST_APTR)FUNCARRAY_BEGIN,
	(CONST_APTR)FUNCARRAY_32BIT_NATIVE,
#endif
	(CONST_APTR)lib_open,
	(CONST_APTR)lib_close,
	(CONST_APTR)lib_expunge,
	(CONST_APTR)lib_null,
	(CONST_APTR)objc_init_m68k,
	(CONST_APTR)__objc_exec_class_m68k,
	(CONST_APTR)objc_msg_lookup_m68k,
	(CONST_APTR)objc_msg_lookup_stret_m68k,
	(CONST_APTR)objc_msg_lookup_super_m68k,
	(CONST_APTR)objc_msg_lookup_super_stret_m68k,
	(CONST_APTR)objc_lookUpClass_m68k,
	(CONST_APTR)objc_getClass_m68k,
	(CONST_APTR)objc_getRequiredClass_m68k,
	(CONST_APTR)objc_lookup_class_m68k,
	(CONST_APTR)objc_get_class_m68k,
	(CONST_APTR)objc_exception_throw_m68k,
	(CONST_APTR)objc_sync_enter_m68k,
	(CONST_APTR)objc_sync_exit_m68k,
	(CONST_APTR)objc_getProperty_m68k,
	(CONST_APTR)objc_setProperty_m68k,
	(CONST_APTR)objc_getPropertyStruct_m68k,
	(CONST_APTR)objc_setPropertyStruct_m68k,
	(CONST_APTR)objc_enumerationMutation_m68k,
	(CONST_APTR)__gnu_objc_personality_v0_m68k,
	(CONST_APTR)objc_retain_m68k,
	(CONST_APTR)objc_retainBlock_m68k,
	(CONST_APTR)objc_retainAutorelease_m68k,
	(CONST_APTR)objc_release_m68k,
	(CONST_APTR)objc_autorelease_m68k,
	(CONST_APTR)objc_autoreleaseReturnValue_m68k,
	(CONST_APTR)objc_retainAutoreleaseReturnValue_m68k,
	(CONST_APTR)objc_retainAutoreleasedReturnValue_m68k,
	(CONST_APTR)objc_storeStrong_m68k,
	(CONST_APTR)objc_storeWeak_m68k,
	(CONST_APTR)objc_loadWeakRetained_m68k,
	(CONST_APTR)objc_initWeak_m68k,
	(CONST_APTR)objc_destroyWeak_m68k,
	(CONST_APTR)objc_loadWeak_m68k,
	(CONST_APTR)objc_copyWeak_m68k,
	(CONST_APTR)objc_moveWeak_m68k,
	(CONST_APTR)sel_registerName_m68k,
	(CONST_APTR)sel_getName_m68k,
	(CONST_APTR)sel_isEqual_m68k,
	(CONST_APTR)objc_allocateClassPair_m68k,
	(CONST_APTR)objc_registerClassPair_m68k,
	(CONST_APTR)objc_getClassList_m68k,
	(CONST_APTR)objc_copyClassList_m68k,
	(CONST_APTR)class_isMetaClass_m68k,
	(CONST_APTR)class_getName_m68k,
	(CONST_APTR)class_getSuperclass_m68k,
	(CONST_APTR)class_getInstanceSize_m68k,
	(CONST_APTR)class_respondsToSelector_m68k,
	(CONST_APTR)class_conformsToProtocol_m68k,
	(CONST_APTR)class_getMethodImplementation_m68k,
	(CONST_APTR)class_getMethodImplementation_stret_m68k,
	(CONST_APTR)class_getMethodTypeEncoding_m68k,
	(CONST_APTR)class_addMethod_m68k,
	(CONST_APTR)class_replaceMethod_m68k,
	(CONST_APTR)object_getClass_m68k,
	(CONST_APTR)object_setClass_m68k,
	(CONST_APTR)object_getClassName_m68k,
	(CONST_APTR)protocol_getName_m68k,
	(CONST_APTR)protocol_isEqual_m68k,
	(CONST_APTR)protocol_conformsToProtocol_m68k,
	(CONST_APTR)objc_exit_m68k,
	(CONST_APTR)objc_setUncaughtExceptionHandler_m68k,
	(CONST_APTR)objc_setForwardHandler_m68k,
	(CONST_APTR)objc_setEnumerationMutationHandler_m68k,
	(CONST_APTR)objc_zero_weak_references_m68k,
	(CONST_APTR)-1,
#ifdef OF_MORPHOS
	(CONST_APTR)FUNCARRAY_END
#endif
};
#pragma GCC diagnostic pop

static struct {
	ULONG dataSize;
	CONST_APTR *functionTable;
	ULONG *dataTable;
	struct Library *(*initFunc)(
	    struct ObjFWRTBase *base OBJC_M68K_REG(d0),
	    void *segList OBJC_M68K_REG(a0),
	    struct ExecBase *execBase OBJC_M68K_REG(a6));
} init_table = {
	sizeof(struct ObjFWRTBase),
	functionTable,
	NULL,
	lib_init
};

struct Resident resident = {
	.rt_MatchWord = RTC_MATCHWORD,
	.rt_MatchTag = &resident,
	.rt_EndSkip = &resident + 1,
	.rt_Flags = RTF_AUTOINIT
#ifdef OF_MORPHOS
	    | RTF_PPC | RTF_EXTENDED
#endif
	    ,
	.rt_Version = OBJFWRT_LIB_MAJOR,
	.rt_Type = NT_LIBRARY,
	.rt_Pri = 0,
	.rt_Name = (char *)OBJFWRT_AMIGA_LIB,
	.rt_IdString = (char *)"ObjFWRT " VERSION_STRING
	    " \xA9 2008-2019 Jonathan Schleifer",
	.rt_Init = &init_table,
#ifdef OF_MORPHOS
	.rt_Revision = OBJFWRT_LIB_MINOR,
	.rt_Tags = NULL,
#endif
};

#ifdef OF_MORPHOS
__asm__ (
    ".section .ctors, \"aw\", @progbits\n"
    "ctors:\n"
    "	.long -1\n"
    ".section .text"
);
#endif
