char allow

• 0x09
• 0x11 to 0x13
• 0x20 to 0x23
• 0x25 to 0x3F
• 0x41 to 0x5F
• 0x61 to 0x7E

C Keyword

auto break case char const continue default do double else enum extern float for goto if inline (C99) int long register restrict (C99) return short signed sizeof static struct switch typedef union unsigned void volatile while

C Preprocessor Keyword

if elif else endif

ifdef ifndef define undef

include line error pragma

defined

AST

struct node {
    struct node *parent # +0
    struct node *left;  # +8
    struct node *right; # +16
    int nodetype;       # +24
    void *value;        # +32
};
sizeof(struct node) = 40;

nodeType	type number	value	value is ptr
null	0	null	[ ]
return	1	return code	[x]
function	2	name of function	[x]
int	4	not a node type	[ ]
call	8	name of function	[x]
define variable	16	name of variable defined	[x]
assing variable	32	name of variable	[x]
value of variable	64	value of variable	[x]

Varible list

struct variable {
    struct variable *next; # +0
    char *name;            # +8
    void *value;           # +16 default value
    uint type;              # +24
    uint offset;            # +28
};
sizeof(struct variable) = 32;

variable type	value
void	0
int	1

Link elf using ld

ld -o a.out /lib/crt1.o /lib/crti.o /lib/crtn.o -lc simpleMain.o --dynamic-linker /lib64/ld-linux-x86-64.so.2

TODO

open syscall

File Access Modes

• O_RDONLY: 0 (0000 in octal)
• O_WRONLY: 1 (0001 in octal)
• O_RDWR: 2 (0002 in octal)

File Creation and Status Flags

• O_CREAT: 64 (0100 in octal)
• O_EXCL: 128 (0200 in octal)
• O_NOCTTY: 256 (0400 in octal)
• O_TRUNC: 512 (01000 in octal)

File Status Flags

• O_APPEND: 1024 (02000 in octal)
• O_ASYNC: 8192 (020000 in octal)
• O_DIRECT: 16384 (040000 in octal)
• O_DIRECTORY: 65536 (0200000 in octal)
• O_NOATIME: 262144 (01000000 in octal)
• O_NOFOLLOW: 131072 (0400000 in octal)
• O_NONBLOCK or O_NDELAY: 2048 (04000 in octal)
• O_SYNC: 129024 (04010000 in octal)
• O_DSYNC: 4096 (010000 in octal)
• O_RSYNC: 1052672 (04010000 in octal)
• O_CLOEXEC: 524288 (02000000 in octal)
• O_TMPFILE: 4294967296 (010000000000 in octal)