symbol.h File Reference

#include <stdint.h>

Go to the source code of this file.

Data Structures
struct	C8_InstructionFormat
	Represents a valid instruction format. More...
struct	C8_Instruction
	Represents an instruction. More...
struct	C8_Label
	Represents a label. More...
struct	C8_LabelList
	Represents a list of labels. More...
struct	C8_Symbol
	Represents a symbol with a type, value, and line number. More...
struct	C8_SymbolList
	Represents a symbol with a type, value, and line number. More...

Macros
#define	C8_INSTRUCTION_COUNT   64
	Initial instruction list ceiling.
#define	C8_LABEL_CEILING   64
	Initial label list ceiling.
#define	C8_LABEL_IDENTIFIER_SIZE   20
	Maximum size of label identifier.
#define	C8_SYMBOL_CEILING   64
	Initial symbol list ceiling.
#define	C8_S_CLS   "CLS"
#define	C8_S_RET   "RET"
#define	C8_S_JP   "JP"
#define	C8_S_CALL   "CALL"
#define	C8_S_SE   "SE"
#define	C8_S_SNE   "SNE"
#define	C8_S_LD   "LD"
#define	C8_S_ADD   "ADD"
#define	C8_S_OR   "OR"
#define	C8_S_AND   "AND"
#define	C8_S_SUB   "SUB"
#define	C8_S_SHR   "SHR"
#define	C8_S_SUBN   "SUBN"
#define	C8_S_SHL   "SHL"
#define	C8_S_RND   "RND"
#define	C8_S_DRW   "DRW"
#define	C8_S_SKP   "SKP"
#define	C8_S_SKNP   "SKNP"
#define	C8_S_XOR   "XOR"
#define	C8_S_SCD   "SCD"
#define	C8_S_SCR   "SCR"
#define	C8_S_SCL   "SCL"
#define	C8_S_EXIT   "EXIT"
#define	C8_S_LOW   "LOW"
#define	C8_S_HIGH   "HIGH"
#define	C8_S_JP_V0   "JP V0,"
#define	C8_S_K   "K"
#define	C8_S_F   "F"
#define	C8_S_B   "B"
#define	C8_S_DT   "DT"
#define	C8_S_ST   "ST"
#define	C8_S_I   "I"
#define	C8_S_IP   "[I]"
#define	C8_S_DB   ".DB"
#define	C8_S_DW   ".DW"
#define	C8_S_DS   ".DS"
#define	C8_S_HF   "HF"
#define	C8_S_R   "R"

Enumerations
enum	C8_InstructionIdentifier {   C8_I_NULL = -1 , C8_I_CLS , C8_I_RET , C8_I_JP ,   C8_I_CALL , C8_I_SE , C8_I_SNE , C8_I_LD ,   C8_I_ADD , C8_I_OR , C8_I_AND , C8_I_SUB ,   C8_I_SHR , C8_I_SUBN , C8_I_SHL , C8_I_RND ,   C8_I_DRW , C8_I_SKP , C8_I_SKNP , C8_I_XOR ,   C8_I_SCD , C8_I_SCR , C8_I_SCL , C8_I_EXIT ,   C8_I_LOW , C8_I_HIGH , C8_I_JP_V0 }
	Represents instruction types. More...
enum	C8_SymbolIdentifier {   C8_SYM_NULL , C8_SYM_DT , C8_SYM_ST , C8_SYM_I ,   C8_SYM_IP , C8_SYM_K , C8_SYM_F , C8_SYM_B ,   C8_SYM_DB , C8_SYM_DW , C8_SYM_DS , C8_SYM_HF ,   C8_SYM_R , C8_SYM_LABEL , C8_SYM_INT , C8_SYM_INT4 ,   C8_SYM_INT8 , C8_SYM_INT12 , C8_SYM_STRING , C8_SYM_V ,   C8_SYM_INSTRUCTION , C8_SYM_LABEL_DEFINITION }
	Represents symbol types. More...

Functions
int	c8_build_instruction (C8_Instruction *, C8_SymbolList *, int)
	Build an instruction from symbols beginning at idx.
int	c8_is_comment (const char *)
	Check if the given string is a comment.
int	c8_is_db (const char *)
	Check if given string is a DB identifier.
int	c8_is_ds (const char *)
	Check if given string is a DS identifier.
int	c8_is_dw (const char *)
	Check if given string is a DW identifier.
int	c8_is_instruction (const char *)
	Check if the given string is an instruction.
int	c8_is_label_definition (const char *)
	Check if the given string is a label definition.
int	c8_is_label (const char *, const C8_LabelList *)
	Check if given string is a label reference.
int	c8_is_register (const char *)
	Check if the given string represents a V register.
int	c8_is_reserved_identifier (const char *)
	Check if given string is a reserved identifier.
C8_Symbol *	c8_next_symbol (C8_SymbolList *)
	Get the next symbol.
int	c8_populate_labels (C8_LabelList *)
	Populate label list from lines.
int	c8_resolve_labels (C8_SymbolList *, C8_LabelList *)
	Get byte indexes of label definitions from completed symbol table.
int	c8_shift (uint16_t)
	Find the bits needed to shift to OR a parameter into an instruction.
int	c8_substitute_labels (C8_SymbolList *, C8_LabelList *)
	Substitute label symbols with their corresponding int value.

Variables
const char *	c8_instructionStrings []
const char *	c8_identifierStrings []
C8_InstructionFormat	c8_formats []

Detailed Description

Note

NOT EXPORTED

Stuff for parsing symbols and instructions for encoding CHIP-8 "assembly".

Macro Definition Documentation

C8_INSTRUCTION_COUNT

#define C8_INSTRUCTION_COUNT   64

Initial instruction list ceiling.

C8_LABEL_CEILING

#define C8_LABEL_CEILING   64

Initial label list ceiling.

C8_LABEL_IDENTIFIER_SIZE

#define C8_LABEL_IDENTIFIER_SIZE   20

Maximum size of label identifier.

C8_S_ADD

#define C8_S_ADD   "ADD"

C8_S_AND

#define C8_S_AND   "AND"

C8_S_B

#define C8_S_B   "B"

C8_S_CALL

#define C8_S_CALL   "CALL"

C8_S_CLS

#define C8_S_CLS   "CLS"

C8_S_DB

#define C8_S_DB   ".DB"

C8_S_DRW

#define C8_S_DRW   "DRW"

C8_S_DS

#define C8_S_DS   ".DS"

C8_S_DT

#define C8_S_DT   "DT"

C8_S_DW

#define C8_S_DW   ".DW"

C8_S_EXIT

#define C8_S_EXIT   "EXIT"

C8_S_F

#define C8_S_F   "F"

C8_S_HF

#define C8_S_HF   "HF"

C8_S_HIGH

#define C8_S_HIGH   "HIGH"

C8_S_I

#define C8_S_I   "I"

C8_S_IP

#define C8_S_IP   "[I]"

C8_S_JP

#define C8_S_JP   "JP"

C8_S_JP_V0

#define C8_S_JP_V0   "JP V0,"

C8_S_K

#define C8_S_K   "K"

C8_S_LD

#define C8_S_LD   "LD"

C8_S_LOW

#define C8_S_LOW   "LOW"

C8_S_OR

#define C8_S_OR   "OR"

C8_S_R

#define C8_S_R   "R"

C8_S_RET

#define C8_S_RET   "RET"

C8_S_RND

#define C8_S_RND   "RND"

C8_S_SCD

#define C8_S_SCD   "SCD"

C8_S_SCL

#define C8_S_SCL   "SCL"

C8_S_SCR

#define C8_S_SCR   "SCR"

C8_S_SE

#define C8_S_SE   "SE"

C8_S_SHL

#define C8_S_SHL   "SHL"

C8_S_SHR

#define C8_S_SHR   "SHR"

C8_S_SKNP

#define C8_S_SKNP   "SKNP"

C8_S_SKP

#define C8_S_SKP   "SKP"

C8_S_SNE

#define C8_S_SNE   "SNE"

C8_S_ST

#define C8_S_ST   "ST"

C8_S_SUB

#define C8_S_SUB   "SUB"

C8_S_SUBN

#define C8_S_SUBN   "SUBN"

C8_S_XOR

#define C8_S_XOR   "XOR"

C8_SYMBOL_CEILING

#define C8_SYMBOL_CEILING   64

Initial symbol list ceiling.

Enumeration Type Documentation

C8_InstructionIdentifier

enum C8_InstructionIdentifier

Represents instruction types.

This enumeration defines all possible CHIP-8 instructions.

NOTE: values to be kept in same order as instructionStrings

Enumerator
C8_I_NULL
C8_I_CLS
C8_I_RET
C8_I_JP
C8_I_CALL
C8_I_SE
C8_I_SNE
C8_I_LD
C8_I_ADD
C8_I_OR
C8_I_AND
C8_I_SUB
C8_I_SHR
C8_I_SUBN
C8_I_SHL
C8_I_RND
C8_I_DRW
C8_I_SKP
C8_I_SKNP
C8_I_XOR
C8_I_SCD
C8_I_SCR
C8_I_SCL
C8_I_EXIT
C8_I_LOW
C8_I_HIGH
C8_I_JP_V0

C8_SymbolIdentifier

enum C8_SymbolIdentifier

Represents symbol types.

This enumeration defines all symbol types found during the first assembler pass.

NOTE: Values before label need to be kept in same order as identifierStrings

Enumerator
C8_SYM_NULL
C8_SYM_DT
C8_SYM_ST
C8_SYM_I
C8_SYM_IP
C8_SYM_K
C8_SYM_F
C8_SYM_B
C8_SYM_DB
C8_SYM_DW
C8_SYM_DS
C8_SYM_HF
C8_SYM_R
C8_SYM_LABEL
C8_SYM_INT
C8_SYM_INT4
C8_SYM_INT8
C8_SYM_INT12
C8_SYM_STRING
C8_SYM_V
C8_SYM_INSTRUCTION
C8_SYM_LABEL_DEFINITION

Function Documentation

c8_build_instruction()

int c8_build_instruction	(	C8_Instruction *	ins,
		C8_SymbolList *	symbols,
		int	idx
	)

Build an instruction from symbols beginning at idx.

This function builds an instruction from a completely parsed set of symbols (with labels expanded).

Parameters

ins	instruction_t to store instruction contents
symbols	symbol list
idx	symbols index of start of instruction

Returns

instruction bytecode

c8_is_comment()

int c8_is_comment

(

const char *

s

)

Check if the given string is a comment.

Parameters

s	the string to check

Returns

1 if true, 0 if false

c8_is_db()

int c8_is_db

(

const char *

s

)

Check if given string is a DB identifier.

Returns

1 if true, 0 if false

c8_is_ds()

int c8_is_ds

(

const char *

s

)

Check if given string is a DS identifier.

Returns

1 if true, 0 if false

c8_is_dw()

int c8_is_dw

(

const char *

s

)

Check if given string is a DW identifier.

Returns

1 if true, 0 if false

c8_is_instruction()

int c8_is_instruction

(

const char *

s

)

Check if the given string is an instruction.

Parameters

s	the string to check

Returns

instruction enumerator if true, -1 if false

c8_is_label()

int c8_is_label	(	const char *	s,
		const C8_LabelList *	labels
	)

Check if given string is a label reference.

This function checks if the given string is a label reference by comparing it against the label list. It returns the index of the label in the label list if it is found, or -1 if it is not.

This function assumes that the label list has been populated (e.g. populate_labels() has been called).

Parameters

s	string to check
labels	label list to check from

Returns

label index if true, -1 otherwise

c8_is_label_definition()

int c8_is_label_definition

(

const char *

s

)

Check if the given string is a label definition.

Parameters

s	the string to check

Returns

1 if true, 0 if false

c8_is_register()

int c8_is_register

(

const char *

s

)

Check if the given string represents a V register.

This function checks if the given string starts with 'V' or 'v' and is followed by a valid hexadecimal digit (0-9, A-F, a-f). It returns the register number if it is a valid V register, or -1 if it is not.

Parameters

s	string to check

Returns

V register number if true, -1 otherwise

c8_is_reserved_identifier()

int c8_is_reserved_identifier

(

const char *

s

)

Check if given string is a reserved identifier.

This function checks if the given string is one of the reserved identifiers defined in c8_identifierStrings. It returns the index of the identifier if it is found, or -1 if it is not.

Parameters

s	string to check

Returns

type of identifier if true, -1 otherwise

c8_next_symbol()

C8_Symbol * c8_next_symbol

(

C8_SymbolList *

symbols

)

Get the next symbol.

This function retrieves the next available symbol in the symbol list. If the symbol list is empty, it initializes the first symbol. If the symbol list is full, it reallocates the symbol list to accommodate more symbols.

If symbols is NULL or the symbol list is NULL, it returns NULL.

Parameters

symbols

symbol list to get next symbol from

Returns

first empty symbol in symbol table

c8_populate_labels()

int c8_populate_labels

(

C8_LabelList *

labels

)

Populate label list from lines.

This function scans through the lines of code and identifies label definitions. It checks each line for a label definition (ending with a colon) and adds it to the label list.

If a duplicate label definition is found, it throws a C8_DUPLICATE_LABEL_EXCEPTION.

If too many labels are defined, it throws a C8_TOO_MANY_LABELS_EXCEPTION.

Parameters

labels

label list to populate

Returns

1 if success, 0 or error code otherwise

c8_resolve_labels()

int c8_resolve_labels	(	C8_SymbolList *	symbols,
		C8_LabelList *	labels
	)

Get byte indexes of label definitions from completed symbol table.

This function resolves label definitions in the symbol list and populates the label list with the byte index of each label definition. It iterates through the symbols, keeping track of the current byte position in the program. When it encounters a label definition, it records the current byte position in the label list. It also increments the byte position based on the type of symbol encountered (e.g., SYM_DB increments by 1, SYM_INSTRUCTION and SYM_DW increment by 2).

This function assumes that the symbol list has been populated and that the symbols have been parsed correctly. It also assumes that the label list has been initialized.

This function will return 1 if all labels were resolved successfully, or 0 if there was a failure (e.g., if the label list is not fully populated).

Parameters

symbols	list of symbols
labels	list of labels

Returns

1 if success, 0 if failure

c8_shift()

int c8_shift

(

uint16_t

fmt

)

Find the bits needed to shift to OR a parameter into an instruction.

This function finds the bits needed to shift to OR a parameter into an instruction. It is used to determine the position of parameters in the instruction bytecode.

This is a workaround for the fact that the instruction formats are not defined in a way that allows for easy bit manipulation.

Parameters

fmt	C8_InstructionFormat pformat to check

Returns

number of bits to shift

c8_substitute_labels()

int c8_substitute_labels	(	C8_SymbolList *	symbols,
		C8_LabelList *	labels
	)

Substitute label symbols with their corresponding int value.

This function replaces all symbols of type C8_SYM_LABEL in the symbol list with their corresponding byte value from the label list. It checks if the label exists and throws an C8_INVALID_SYMBOL_EXCEPTION if it does not.

This function assumes that the label list has been populated and that their byte values have been set correctly.

Parameters

symbols	symbols to search
labels	labels to search

Variable Documentation

c8_formats

C8_InstructionFormat c8_formats[]

extern

All valid instruction formats

c8_identifierStrings

const char* c8_identifierStrings[]

extern

Reserved identifier strings. Has to match Symbol.

c8_instructionStrings

const char* c8_instructionStrings[]

extern

Instruction strings. Has to match Instruction.