/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
 *               2018
 *   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 "ObjFW_RT.h"
#import "private.h"
#import "platform.h"

#ifdef OF_AMIGAOS3
# define INTUITION_CLASSES_H
#endif

#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(OBJFW_RT_LIB_MAJOR, OBJFW_RT_LIB_MINOR)

#define DATA_OFFSET 0x7FFE

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

struct ObjFWRTBase {
	struct Library library;
	void *seg_list;
	struct ObjFWRTBase *parent;
	char *data_seg;
	bool initialized;
	struct objc_libc libc;
};

extern uintptr_t __CTOR_LIST__[], __DTOR_LIST__[];
extern const void *_EH_FRAME_BEGINS__;
extern void *_EH_FRAME_OBJECTS__;
extern void *__a4_init, *__data_size;

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

__asm__ (
    ".text\n"
    ".globl ___restore_a4\n"
    ".align 1\n"
    "___restore_a4:\n"
    "	movea.l	42(a6), a4\n"
    "	rts"
);

static OF_INLINE char *
get_data_seg(void)
{
	char *data_seg;

	__asm__ __volatile__ (
	    "move.l	#___a4_init, %0" : "=r"(data_seg)
	);

	return data_seg;
}

static OF_INLINE size_t *
get_datadata_relocs(void)
{
	size_t *datadata_relocs;

	__asm__ __volatile__ (
	    "move.l	#___datadata_relocs, %0" : "=r"(datadata_relocs)
	);

	return datadata_relocs;
}

static struct Library *
lib_init(struct ExecBase *sys_base OBJC_M68K_REG("a6"),
    void *seg_list OBJC_M68K_REG("a0"),
    struct ObjFWRTBase *base OBJC_M68K_REG("d0"))
{
	__asm__ __volatile__ (
	    "move.l	a6, _SysBase" :: "a"(sys_base)
	);

	base->seg_list = seg_list;
	base->parent = NULL;
	base->data_seg = get_data_seg();

	return &base->library;
}

struct Library *__saveds
OBJC_M68K_FUNC(lib_open, struct ObjFWRTBase *base OBJC_M68K_REG("a6"))
{
	OBJC_M68K_ARG(struct ObjFWRTBase *, base, REG_A6)
	struct ObjFWRTBase *child;
	size_t data_size, *datadata_relocs;
	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;

	data_size = (uintptr_t)&__data_size -
	    ((uintptr_t)&__a4_init - DATA_OFFSET);

	if ((child->data_seg = AllocMem(data_size, 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->data_seg, base->data_seg - DATA_OFFSET, data_size);

	datadata_relocs = get_datadata_relocs();
	displacement = child->data_seg - (base->data_seg - DATA_OFFSET);

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

	child->data_seg += DATA_OFFSET;

	return &child->library;
}

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

	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;
	}

	seg_list = base->seg_list;

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

	return seg_list;
}

static void *__saveds
OBJC_M68K_FUNC(lib_expunge, struct ObjFWRTBase *base OBJC_M68K_REG("a6"))
{
	OBJC_M68K_ARG(struct ObjFWRTBase *, base, REG_A6)

	return expunge(base);
}

static void *__saveds
OBJC_M68K_FUNC(lib_close, struct ObjFWRTBase *base OBJC_M68K_REG("a6"))
{
	OBJC_M68K_ARG(struct ObjFWRTBase *, base, REG_A6)

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

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

		parent = base->parent;

		FreeMem(base->data_seg - DATA_OFFSET, (uintptr_t)&__data_size -
		    ((uintptr_t)&__a4_init - DATA_OFFSET));
		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 0;
}

static void *
lib_null(void)
{
	return 0;
}

static bool __saveds
objc_init(unsigned int version OBJC_M68K_REG("d0"),
    struct objc_libc *libc OBJC_M68K_REG("a0"),
    FILE *stdout_ OBJC_M68K_REG("a1"), FILE *stderr_ OBJC_M68K_REG("a2"))
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");
	uintptr_t *iter, *iter0;

	if (version > 1)
		return false;

	memcpy(&base->libc, libc, sizeof(base->libc));

	stdout = stdout_;
	stderr = stderr_;

	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++)
		base->libc.__register_frame_info((&_EH_FRAME_BEGINS__)[i],
		    (&_EH_FRAME_OBJECTS__)[i]);

	iter0 = &__CTOR_LIST__[1];
	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)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc.malloc(size);
}

void *
calloc(size_t count, size_t size)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc.calloc(count, size);
}

void *
realloc(void *ptr, size_t size)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc.realloc(ptr, size);
}

void
free(void *ptr)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	base->libc.free(ptr);
}

int
fprintf(FILE *restrict stream, const char *restrict fmt, ...)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");
	int ret;
	va_list args;

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

	return ret;
}

int
fflush(FILE *restrict stream)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc.fflush(stream);
}

void
exit(int status)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	base->libc.exit(status);
}

void
abort(void)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	base->libc.abort();
}

int
_Unwind_RaiseException(void *ex)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc._Unwind_RaiseException(ex);
}

void
_Unwind_DeleteException(void *ex)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	base->libc._Unwind_DeleteException(ex);
}

void *
_Unwind_GetLanguageSpecificData(void *ctx)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc._Unwind_GetLanguageSpecificData(ctx);
}

uintptr_t
_Unwind_GetRegionStart(void *ctx)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc._Unwind_GetRegionStart(ctx);
}

uintptr_t
_Unwind_GetDataRelBase(void *ctx)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc._Unwind_GetDataRelBase(ctx);
}

uintptr_t
_Unwind_GetTextRelBase(void *ctx)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc._Unwind_GetTextRelBase(ctx);
}

uintptr_t
_Unwind_GetIP(void *ctx)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc._Unwind_GetIP(ctx);
}

uintptr_t
_Unwind_GetGR(void *ctx, int gr)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	return base->libc._Unwind_GetGR(ctx, gr);
}

void
_Unwind_SetIP(void *ctx, uintptr_t ip)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	base->libc._Unwind_SetIP(ctx, ip);
}

void
_Unwind_SetGR(void *ctx, int gr, uintptr_t value)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	base->libc._Unwind_SetGR(ctx, gr, value);
}

void
_Unwind_Resume(void *ex)
{
	register struct ObjFWRTBase *base OBJC_M68K_REG("a6");

	base->libc._Unwind_Resume(ex);
}

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic"
static CONST_APTR function_table[] = {
	(CONST_APTR)lib_open,
	(CONST_APTR)lib_close,
	(CONST_APTR)lib_expunge,
	(CONST_APTR)lib_null,
#include "amiga-library-functable.inc"
	(CONST_APTR)-1,
};
#pragma GCC diagnostic pop

static struct {
	ULONG data_size;
	CONST_APTR *function_table;
	ULONG *data_table;
	struct Library *(*init_func)(
	    struct ExecBase *exec_base OBJC_M68K_REG("a6"),
	    void *seg_list OBJC_M68K_REG("a0"),
	    struct ObjFWRTBase *base OBJC_M68K_REG("d0"));
} init_table = {
	sizeof(struct ObjFWRTBase),
	function_table,
	NULL,
	lib_init
};

static struct Resident resident = {
	.rt_MatchWord = RTC_MATCHWORD,
	.rt_MatchTag = &resident,
	.rt_EndSkip = &resident + 1,
	.rt_Flags = RTF_AUTOINIT
#ifndef OF_AMIGAOS3
	    | RTF_PPC
#endif
	    ,
	.rt_Version = OBJFW_RT_LIB_MAJOR,
	.rt_Type = NT_LIBRARY,
	.rt_Pri = 0,
	.rt_Name = (char *)"objfw_rt.library",
	.rt_IdString = (char *)"ObjFW_RT " VERSION_STRING
	    " \xA9 2008-2018 Jonathan Schleifer",
	.rt_Init = &init_table
};