package core:rexcode/isa

Source

Branch_Target :: struct {
	inst_idx: u32,
	// which decoded instruction has the branch
	op_idx:   u8,
	// which operand of that instruction is the target
	target:   u32,
}

Error :: struct #packed {
	inst_idx: u32,
	// Which instruction failed (or byte offset for decode)
	code:     Error_Code,
	_:        [3]u8,
}

Error_Code :: enum u8 {
	NONE                   = 0, 
	// Shared encoding errors
	INVALID_MNEMONIC, 
	NO_MATCHING_ENCODING, 
	OPERAND_MISMATCH, 
	IMMEDIATE_OUT_OF_RANGE, 
	BUFFER_OVERFLOW, 
	LABEL_OUT_OF_RANGE, 
	INVALID_OPERAND_COUNT,      // operand_count > 4 or doesn't match operands
	// Shared decoding errors
	BUFFER_TOO_SHORT, 
	INVALID_OPCODE, 
	// x86-specific decoding errors
	INVALID_MODRM, 
	INVALID_SIB, 
	INVALID_PREFIX, 
	INVALID_VEX, 
	INVALID_EVEX, 
	TOO_MANY_PREFIXES, 
}

Label_Definition :: distinct u32

Label_Map :: struct {
	labels: [dynamic]Label_Definition,
	names:  map[string]u32,
}

Print_Options :: struct {
	uppercase:         bool,
	// uppercase mnemonics/registers
	hex_prefix:        string,
	// hex prefix (default "0x")
	hex_lowercase:     bool,
	label_prefix:      string,
	// default ".L"
	show_offsets:      bool,
	// show byte offsets before each instruction
	indent:            string,
	// default "    "
	separator:         string,
	// default "\n"
	space_after_comma: bool,
}

Print_Result :: struct {
	text:   string,
	// formatted disassembly text
	tokens: []Token,
}

Token :: struct {
	offset:            u32,
	// byte offset in output string
	length:            u16,
	// length in bytes
	kind:              Token_Kind,
	instruction_index: u16,
}

Token_Kind :: enum u8 {
	WHITESPACE,      // spaces, tabs, indentation
	NEWLINE,         // line breaks
	LABEL_DEF,       // label definition (e.g., ".L1:")
	LABEL_REF,       // label reference in operand
	OFFSET,          // byte offset prefix (e.g., "0x10:")
	MNEMONIC,        // instruction mnemonic
	REGISTER,        // register name
	IMMEDIATE,       // immediate value
	MEMORY_BRACKET,  // '[' or ']'
	MEMORY_OPERATOR, // '+', '-', '*' in memory operands
	MEMORY_DISP,     // displacement in memory operand
	MEMORY_SCALE,    // scale factor in memory operand
	PUNCTUATION,     // comma separator, colon
	COMMENT, 
}

DEFAULT_PRINT_OPTIONS :: Print_Options{uppercase = false, hex_prefix = "0x", hex_lowercase = true, label_prefix = ".L", show_offsets = false, indent = "    ", separator = "\n", space_after_comma = true}

LABEL_UNDEFINED :: Label_Definition(0xFFFFFFFF)

infer_labels_from_branches :: proc(branches: []Branch_Target, decoded_end: u32, label_defs: ^[dynamic]Label_Definition, relocs: []$R) {…}

label :: proc(labels: ^[dynamic]Label_Definition, instructions: ^[dynamic]$T) -> u32 {…}

label_forward :: proc(labels: ^[dynamic]Label_Definition) -> u32 {…}

label_map_destroy :: proc(lm: ^Label_Map) {…}

label_map_init :: proc(lm: ^Label_Map, allocator := context.allocator) {…}

label_named :: proc(lm: ^Label_Map, name: string, instructions: ^[dynamic]$T) -> u32 {…}

label_reserve :: proc(lm: ^Label_Map, name: string) -> u32 {…}

label_set :: proc(lm: ^Label_Map, name: string, instructions: ^[dynamic]$T) {…}

label_set_at :: proc(labels: ^[dynamic]Label_Definition, id: u32, instructions: ^[dynamic]$T) {…}

print_decimal :: proc(sb: ^strings.Builder, value: u32) {…}

print_hex :: proc(sb: ^strings.Builder, value: u64, options: ^Print_Options) {…}

print_hex_digits :: proc(sb: ^strings.Builder, value: u64, options: ^Print_Options) {…}

rewrite_label_defs_to_offsets :: proc(label_defs: []Label_Definition, inst_offsets: []u32) {…}

token_kind_to_string :: proc(k: Token_Kind) -> string {…}