#ifdef HAVE_CONFIG_H
# include "config.h"
#endif /* HAVE_CONFIG_H */

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <tcc.h>

#ifdef TCC_MEMORY_DEBUG
# undef tcc_free
# undef tcc_malloc
# undef tcc_mallocz
# undef tcc_realloc
# undef tcc_strdup
#endif /* TCC_MEMORY_DEBUG */

static void *
default_reallocator(void *ptr, size_t size)
{
	void *ptr1;

	if (size == 0)
	{
		free(ptr);
		return (NULL);
	}

	ptr1 = realloc(ptr, size);
	if (ptr1 == NULL)
	{
		fprintf(stderr, "memory full\n");
		exit(EXIT_FAILURE);
	}

	return (ptr1);
}

static TCCReallocFunc *reallocator = default_reallocator;

void
tcc_set_realloc(TCCReallocFunc *my_realloc)
{
	if (my_realloc == NULL)
	{
		reallocator = default_reallocator;
		return;
	}

	reallocator = my_realloc;
}

void
tcc_free(void *ptr)
{
	reallocator(ptr, 0);
}

void *
tcc_malloc(size_t size)
{
	return (reallocator(NULL, size));
}

void *
tcc_mallocz(size_t size)
{
	void *ptr;

	ptr = tcc_malloc(size);
	if (ptr == NULL)
	{
		return (NULL);
	}
	memset(ptr, 0, size);

	return (ptr);
}

void *
tcc_realloc(void *ptr, size_t size)
{
	return (reallocator(ptr, size));
}

char *
tcc_strdup(const char *str)
{
	char *ptr;

	ptr = tcc_malloc(strlen(str) + 1);
	strcpy(ptr, str);

	return (ptr);
}

#ifdef TCC_MEMORY_DEBUG

# define MEMORY_DEBUG_MAGIC1 0xFEEDDEB1
# define MEMORY_DEBUG_MAGIC2 0xFEEDDEB2
# define MEMORY_DEBUG_MAGIC3 0xFEEDDEB3

# define MEMORY_DEBUG_FILE_LEN 40

# define MEMORY_DEBUG_CHECK3(hdr) \
	((MemoryDebugHeader *)((uint8_t *)hdr + header->size))->magic3

# define MEMORY_USER_PTR(hdr) \
	((uint8_t *)header + offsetof(MemoryDebugHeader, magic3))

# define MEMORY_HEADER_PTR(ptr) \
	(MemoryDebugHeader *)((uint8_t *)ptr - offsetof(MemoryDebugHeader, magic3))

typedef struct MemoryDebugHeader {
	uint32_t magic1;
	size_t size;
	struct MemoryDebugHeader *prev;
	struct MemoryDebugHeader *next;
	int linenum;
	char filename[MEMORY_DEBUG_FILE_LEN + 1];
	uint32_t magic2;
	__attribute__((aligned(16))) uint8_t magic3[4];
} MemoryDebugHeader;

TCC_SEM(static mem_sem);
static MemoryDebugHeader *mem_debug_chain;
static size_t mem_cur_size;
size_t mem_max_size;
static int nb_states;

static MemoryDebugHeader *
malloc_check(void *ptr, const char *msg)
{
	MemoryDebugHeader *header;

	header = MEMORY_HEADER_PTR(ptr);
	if (header->magic1 != MEMORY_DEBUG_MAGIC1
		|| header->magic2 != MEMORY_DEBUG_MAGIC2
		|| read32le(MEMORY_DEBUG_CHECK3(header)) != MEMORY_DEBUG_MAGIC3
		|| header->size == (size_t)-1)
	{
		fprintf(stderr, "%s check failed\n", msg);
		if (header->magic1 == MEMORY_DEBUG_MAGIC1)
		{
			fprintf(stderr, "%s:%u: block allocated here.\n",
				header->filename, header->linenum);
		}
		exit(EXIT_FAILURE);
	}

	return (header);
}

void
tcc_free_debug(void *ptr)
{
	MemoryDebugHeader *header;

	if (ptr == NULL)
	{
		return;
	}

	header = malloc_check(ptr, "tcc_free");

	WAIT_SEM(&mem_sem);

	mem_cur_size -= header->size;
	header->size = (size_t)-1;
	if (header->next)
	{
		header->next->prev = header->prev;
	}
	if (header->prev)
	{
		header->prev->next = header->next;
	}
	if (header == mem_debug_chain)
	{
		mem_debug_chain = header->next;
	}

	POST_SEM(&mem_sem);

	tcc_free(header);
}

void *
tcc_malloc_debug(size_t size, const char *file, int line)
{
	int ofs;
	MemoryDebugHeader *header;

	if (size == 0)
	{
		return (NULL);
	}
	header = tcc_malloc(sizeof(MemoryDebugHeader) + size);
	header->magic1 = MEMORY_DEBUG_MAGIC1;
	header->magic2 = MEMORY_DEBUG_MAGIC2;
	header->size = size;
	write32le(MEMORY_DEBUG_CHECK3(header), MEMORY_DEBUG_MAGIC3);
	header->linenum = line;
	ofs = strlen(file) - MEMORY_DEBUG_FILE_LEN;
	strncpy(header->filename, file + (ofs > 0 ? ofs : 0), MEMORY_DEBUG_FILE_LEN);
	header->filename[MEMORY_DEBUG_FILE_LEN] = 0;

	WAIT_SEM(&mem_sem);

	header->next = mem_debug_chain;
	header->prev = NULL;
	if (header->next)
	{
		header->next->prev = header;
	}
	mem_debug_chain = header;
	mem_cur_size += size;
	if (mem_cur_size > mem_max_size)
	{
		mem_max_size = mem_cur_size;
	}

	POST_SEM(&mem_sem);

	return (MEMORY_USER_PTR(header));
}

void *
tcc_mallocz_debug(size_t size, const char *file, int line)
{
	void *ptr;

	ptr = tcc_malloc_debug(size, file, line);
	if (ptr == NULL)
	{
		return (NULL);
	}

	memset(ptr, 0, size);

	return (ptr);
}

void *
tcc_realloc_debug(void *ptr, size_t size, const char *file, int line)
{
	MemoryDebugHeader *header;
	int mem_debug_chain_update;

	mem_debug_chain_update = 0;

	if (ptr == NULL)
	{
		return (tcc_malloc_debug(size, file, line));
	}
	if (size == 0)
	{
		tcc_free_debug(ptr);
		return (NULL);
	}

	header = malloc_check(ptr, "tcc_realloc");

	WAIT_SEM(&mem_sem);

	mem_cur_size -= header->size;
	mem_debug_chain_update = (header == mem_debug_chain);
	header = tcc_realloc(header, sizeof(MemoryDebugHeader) + size);
	header->size = size;
	write32le(MEMORY_DEBUG_CHECK3(header), MEMORY_DEBUG_MAGIC3);
	if (header->next)
	{
		header->next->prev = header;
	}
	if (header->prev)
	{
		header->prev->next = header;
	}
	if (mem_debug_chain_update)
	{
		mem_debug_chain = header;
	}
	mem_cur_size += size;
	if (mem_cur_size > mem_max_size)
	{
		mem_max_size = mem_cur_size;
	}

	POST_SEM(&mem_sem);

	return (MEMORY_USER_PTR(header));
}

char *
tcc_strdup_debug(const char *str, const char *file, int line)
{
	char *ptr;

	ptr = tcc_malloc_debug(strlen(str) + 1, file, line);
	strcpy(ptr, str);

	return (ptr);
}

void
tcc_memcheck(int d)
{
	MemoryDebugHeader *header;

	WAIT_SEM(&mem_sem);

	nb_states += d;
	if (0 == nb_states && mem_cur_size)
	{
		header = mem_debug_chain;
		fflush(stdout);
		fprintf(stderr, "MEM_DEBUG: mem_leak= %d bytes, mem_max_size= %d bytes\n",
			mem_cur_size, mem_max_size);
		while (header)
		{
			fprintf(stderr, "%s:%u: error: %u bytes leaked\n",
				header->filename, header->linenum, header->size);
			header = header->next;
		}
		fflush(stderr);
		mem_cur_size = 0;
		mem_max_size = 0;
		mem_debug_chain = NULL;
#if TCC_MEMORY_DEBUG-0 == 2
		exit(2);
#endif /* TCC_MEMORY_DEBUG == 2 */
	}

	POST_SEM(&mem_sem);
}

#endif /* TCC_MEMORY_DEBUG */