Initial project import

tools/v/vlib/v3/gen/arm64/macho.v

@@ -0,0 +1,297 @@
+// Copyright (c) 2026 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module arm64
+
+// Mach-O Constants for ARM64
+const mh_magic_64 = u32(0xfeedfacf)
+const cpu_type_arm64 = 0x0100000c
+const cpu_subtype_arm64_all = 0
+
+const lc_segment_64 = 0x19
+const lc_symtab = 0x2
+
+const arm64_reloc_branch26 = 2
+const arm64_reloc_page21 = 3
+const arm64_reloc_pageoff12 = 4
+const arm64_reloc_got_load_page21 = 5
+const arm64_reloc_got_load_pageoff12 = 6
+
+pub struct MachOObject {
+pub mut:
+	text_data []u8
+	str_data  []u8
+	data_data []u8
+
+	relocs      []RelocationInfo
+	symbols     []Symbol
+	str_table   []u8
+	sym_by_name map[string]int // symbol name → index in symbols
+}
+
+struct RelocationInfo {
+	addr    int
+	sym_idx int
+	pcrel   bool
+	length  int
+	extern  bool
+	type_   int
+}
+
+struct Symbol {
+mut:
+	name     string
+	type_    u8
+	sect     u8
+	desc     u16
+	value    u64
+	name_off int
+}
+
+pub fn MachOObject.new() &MachOObject {
+	mut m := &MachOObject{
+		text_data:   []u8{}
+		str_data:    []u8{}
+		data_data:   []u8{}
+		relocs:      []RelocationInfo{}
+		symbols:     []Symbol{}
+		str_table:   [u8(0)]
+		sym_by_name: map[string]int{}
+	}
+	return m
+}
+
+pub fn (mut m MachOObject) add_symbol(name string, addr u64, is_ext bool, sect u8) int {
+	typ := if is_ext { u8(0x0f) } else { u8(0x0e) } // N_SECT | N_EXT : N_SECT
+
+	// Check if symbol already exists (e.g., was added as undefined earlier)
+	if i := m.sym_by_name[name] {
+		mut s := &m.symbols[i]
+		s.type_ = typ
+		s.sect = sect
+		s.value = addr
+		return i
+	}
+
+	// Add new symbol
+	idx := m.symbols.len
+	name_off := m.str_table.len
+	unsafe { m.str_table.push_many(name.str, name.len) }
+	m.str_table << 0
+
+	m.symbols << Symbol{
+		name:     name
+		type_:    typ
+		sect:     sect
+		desc:     0
+		value:    addr
+		name_off: name_off
+	}
+	m.sym_by_name[name] = idx
+	return idx
+}
+
+pub fn (mut m MachOObject) add_undefined(name string) int {
+	// Check for any existing symbol with this name (defined or undefined)
+	if i := m.sym_by_name[name] {
+		return i
+	}
+
+	idx := m.symbols.len
+	name_off := m.str_table.len
+	unsafe { m.str_table.push_many(name.str, name.len) }
+	m.str_table << 0
+
+	m.symbols << Symbol{
+		name:     name
+		type_:    0x01 // N_UNDF | N_EXT
+		sect:     0
+		desc:     0
+		value:    0
+		name_off: name_off
+	}
+	m.sym_by_name[name] = idx
+	return idx
+}
+
+pub fn (mut m MachOObject) add_reloc(addr int, sym_idx int, typ int, pcrel bool) {
+	m.relocs << RelocationInfo{
+		addr:    addr
+		sym_idx: sym_idx // 0-based symbol table index
+		type_:   typ
+		pcrel:   pcrel
+		length:  2
+		extern:  true
+	}
+}
+
+pub fn (mut m MachOObject) write(path string) {
+	mut buf := []u8{}
+
+	n_sects := 3
+	header_size := 32
+	seg_cmd_size := 72 + (80 * n_sects)
+	symtab_cmd_size := 24
+	load_cmds_size := seg_cmd_size + symtab_cmd_size
+
+	text_off := header_size + load_cmds_size
+	text_len := m.text_data.len
+	cstring_off := text_off + text_len
+	cstring_len := m.str_data.len
+	data_off := cstring_off + cstring_len
+	data_len := m.data_data.len
+
+	reloc_off := data_off + data_len
+	sym_off := reloc_off + (m.relocs.len * 8)
+	sym_len := m.symbols.len * 16
+	str_off := sym_off + sym_len
+	str_size := m.str_table.len
+
+	// 1. Header
+	write_mh_magic_64(mut buf)
+	write_u32_le(mut buf, u32(cpu_type_arm64))
+	write_u32_le(mut buf, u32(cpu_subtype_arm64_all))
+	write_u32_le(mut buf, 1) // MH_OBJECT
+	write_u32_le(mut buf, 2) // ncmds
+	write_u32_le(mut buf, u32(load_cmds_size))
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+
+	// 2. LC_SEGMENT_64
+	write_u32_le(mut buf, u32(lc_segment_64))
+	write_u32_le(mut buf, u32(seg_cmd_size))
+	for _ in 0 .. 16 {
+		buf << 0
+	}
+	write_u64_le(mut buf, 0)
+	write_u64_le(mut buf, u64(text_len + cstring_len + data_len))
+	write_u64_le(mut buf, u64(text_off))
+	write_u64_le(mut buf, u64(text_len + cstring_len + data_len))
+	write_u32_le(mut buf, 7)
+	write_u32_le(mut buf, 7)
+	write_u32_le(mut buf, u32(n_sects))
+	write_u32_le(mut buf, 0)
+
+	// Section 1: __text
+	write_string_fixed(mut buf, '__text', 16)
+	write_string_fixed(mut buf, '__TEXT', 16)
+	write_u64_le(mut buf, 0) // Addr 0
+	write_u64_le(mut buf, u64(text_len))
+	write_u32_le(mut buf, u32(text_off))
+	write_u32_le(mut buf, 4)
+	write_u32_le(mut buf, u32(reloc_off))
+	write_u32_le(mut buf, u32(m.relocs.len))
+	write_u32_le(mut buf, u32(0x80000400))
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+
+	// Section 2: __cstring
+	write_string_fixed(mut buf, '__cstring', 16)
+	write_string_fixed(mut buf, '__TEXT', 16)
+	write_u64_le(mut buf, u64(text_len)) // Addr = text_len
+	write_u64_le(mut buf, u64(cstring_len))
+	write_u32_le(mut buf, u32(cstring_off))
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 2) // S_CSTRING_LITERALS
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+
+	// Section 3: __data
+	write_string_fixed(mut buf, '__data', 16)
+	write_string_fixed(mut buf, '__DATA', 16)
+	write_u64_le(mut buf, u64(text_len + cstring_len)) // Addr = text_len + cstring_len
+	write_u64_le(mut buf, u64(data_len))
+	write_u32_le(mut buf, u32(data_off))
+	write_u32_le(mut buf, 3) // align 8
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+	write_u32_le(mut buf, 0)
+
+	// 3. LC_SYMTAB
+	write_u32_le(mut buf, u32(lc_symtab))
+	write_u32_le(mut buf, u32(symtab_cmd_size))
+	write_u32_le(mut buf, u32(sym_off))
+	write_u32_le(mut buf, u32(m.symbols.len))
+	write_u32_le(mut buf, u32(str_off))
+	write_u32_le(mut buf, u32(str_size))
+
+	buf << m.text_data
+	buf << m.str_data
+	buf << m.data_data
+
+	for r in m.relocs {
+		write_u32_le(mut buf, u32(r.addr))
+		mut info := u32(r.sym_idx)
+		if r.pcrel {
+			info |= (1 << 24)
+		}
+		info |= (u32(r.length) << 25)
+		if r.extern {
+			info |= (1 << 27)
+		}
+		info |= (u32(r.type_) << 28)
+		write_u32_le(mut buf, info)
+	}
+
+	for s in m.symbols {
+		write_u32_le(mut buf, u32(s.name_off))
+		buf << s.type_
+		buf << s.sect
+		write_u16_le(mut buf, s.desc)
+		write_u64_le(mut buf, s.value)
+	}
+
+	buf << m.str_table
+
+	if !write_file_array_raw(path, buf) {
+		panic('failed to write Mach-O object')
+	}
+}
+
+fn write_u32_le(mut b []u8, v u32) {
+	b << u8(v)
+	b << u8(v >> 8)
+	b << u8(v >> 16)
+	b << u8(v >> 24)
+}
+
+fn write_mh_magic_64(mut b []u8) {
+	b << u8(0xcf)
+	b << u8(0xfa)
+	b << u8(0xed)
+	b << u8(0xfe)
+}
+
+fn write_u64_le(mut b []u8, v u64) {
+	b << u8(v)
+	b << u8(v >> 8)
+	b << u8(v >> 16)
+	b << u8(v >> 24)
+	b << u8(v >> 32)
+	b << u8(v >> 40)
+	b << u8(v >> 48)
+	b << u8(v >> 56)
+}
+
+fn write_u16_le(mut b []u8, v u16) {
+	b << u8(v)
+	b << u8(v >> 8)
+}
+
+fn write_string_fixed(mut b []u8, s string, len int) {
+	mut bytes := s.bytes()
+	for bytes.len < len {
+		bytes << 0
+	}
+	for i in 0 .. len {
+		b << bytes[i]
+	}
+}