Commit 9c3ebe0216306b5e346ec52959de41d1b4d504d9 | zig

author	Jakub Konka <kubkon@jakubkonka.com> 2021-07-01 10:34:46+02:00
committer	Jakub Konka <kubkon@jakubkonka.com> 2021-07-15 18:49:46+02:00
log	9c3ebe0216306b5e346ec52959de41d1b4d504d9
tree	23dd11a4fdb7a8fadbd2ea3b7c6837ec2baef928
parent	e08f7ba8896ad64a696424cff9b9c0963a7a4a0b

zld: clean up logic for creating mach header

4 files changed, 117 insertions(+), 159 deletions(-)

src
- link
  - MachO.zig
  - MachO
    DebugSymbols.zig
    Zld.zig
    commands.zig

src/link/MachO.zig+45-81

...	...	@@ -41,8 +41,6 @@ d_sym: ?DebugSymbols = null,
41	41	/// For x86_64 that's 4KB, whereas for aarch64, that's 16KB.
42	42	page_size: u16,
43	43
44		/// Mach-O header
45		header: ?macho.mach_header_64 = null,
46	44	/// We commit 0x1000 = 4096 bytes of space to the header and
47	45	/// the table of load commands. This should be plenty for any
48	46	/// potential future extensions.
...	...	@@ -128,7 +126,6 @@ offset_table: std.ArrayListUnmanaged(GOTEntry) = .{},
128	126	error_flags: File.ErrorFlags = File.ErrorFlags{},
129	127
130	128	offset_table_count_dirty: bool = false,
131		header_dirty: bool = false,
132	129	load_commands_dirty: bool = false,
133	130	rebase_info_dirty: bool = false,
134	131	binding_info_dirty: bool = false,
...	...	@@ -497,7 +494,6 @@ pub fn flushModule(self: MachO, comp: Compilation) !void {
497	494	}
498	495
499	496	assert(!self.offset_table_count_dirty);
500		assert(!self.header_dirty);
501	497	assert(!self.load_commands_dirty);
502	498	assert(!self.rebase_info_dirty);
503	499	assert(!self.binding_info_dirty);
...	...	@@ -1488,54 +1484,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1488	1484	.Lib => return error.TODOImplementWritingLibFiles,
1489	1485	}
1490	1486
1491		if (self.header == null) {
1492		var header: macho.mach_header_64 = undefined;
1493		header.magic = macho.MH_MAGIC_64;
1494
1495		const CpuInfo = struct {
1496		cpu_type: macho.cpu_type_t,
1497		cpu_subtype: macho.cpu_subtype_t,
1498		};
1499
1500		const cpu_info: CpuInfo = switch (self.base.options.target.cpu.arch) {
1501		.aarch64 => .{
1502		.cpu_type = macho.CPU_TYPE_ARM64,
1503		.cpu_subtype = macho.CPU_SUBTYPE_ARM_ALL,
1504		},
1505		.x86_64 => .{
1506		.cpu_type = macho.CPU_TYPE_X86_64,
1507		.cpu_subtype = macho.CPU_SUBTYPE_X86_64_ALL,
1508		},
1509		else => return error.UnsupportedMachOArchitecture,
1510		};
1511		header.cputype = cpu_info.cpu_type;
1512		header.cpusubtype = cpu_info.cpu_subtype;
1513
1514		const filetype: u32 = switch (self.base.options.output_mode) {
1515		.Exe => macho.MH_EXECUTE,
1516		.Obj => macho.MH_OBJECT,
1517		.Lib => switch (self.base.options.link_mode) {
1518		.Static => return error.TODOStaticLibMachOType,
1519		.Dynamic => macho.MH_DYLIB,
1520		},
1521		};
1522		header.filetype = filetype;
1523		// These will get populated at the end of flushing the results to file.
1524		header.ncmds = 0;
1525		header.sizeofcmds = 0;
1526
1527		switch (self.base.options.output_mode) {
1528		.Exe => {
1529		header.flags = macho.MH_NOUNDEFS \| macho.MH_DYLDLINK \| macho.MH_PIE;
1530		},
1531		else => {
1532		header.flags = 0;
1533		},
1534		}
1535		header.reserved = 0;
1536		self.header = header;
1537		self.header_dirty = true;
1538		}
1539	1487	if (self.pagezero_segment_cmd_index == null) {
1540	1488	self.pagezero_segment_cmd_index = @intCast(u16, self.load_commands.items.len);
1541	1489	try self.load_commands.append(self.base.allocator, .{
...	...	@@ -1543,7 +1491,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1543	1491	.vmsize = 0x100000000, // size always set to 4GB
1544	1492	}),
1545	1493	});
1546		self.header_dirty = true;
1547	1494	self.load_commands_dirty = true;
1548	1495	}
1549	1496	if (self.text_segment_cmd_index == null) {
...	...	@@ -1567,7 +1514,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1567	1514	.initprot = initprot,
1568	1515	}),
1569	1516	});
1570		self.header_dirty = true;
1571	1517	self.load_commands_dirty = true;
1572	1518	}
1573	1519	if (self.text_section_index == null) {
...	...	@@ -1592,7 +1538,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1592	1538	.@"align" = alignment,
1593	1539	.flags = flags,
1594	1540	});
1595		self.header_dirty = true;
1596	1541	self.load_commands_dirty = true;
1597	1542	}
1598	1543	if (self.stubs_section_index == null) {
...	...	@@ -1624,7 +1569,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1624	1569	.flags = flags,
1625	1570	.reserved2 = stub_size,
1626	1571	});
1627		self.header_dirty = true;
1628	1572	self.load_commands_dirty = true;
1629	1573	}
1630	1574	if (self.stub_helper_section_index == null) {
...	...	@@ -1650,7 +1594,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1650	1594	.@"align" = alignment,
1651	1595	.flags = flags,
1652	1596	});
1653		self.header_dirty = true;
1654	1597	self.load_commands_dirty = true;
1655	1598	}
1656	1599	if (self.data_const_segment_cmd_index == null) {
...	...	@@ -1674,7 +1617,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1674	1617	.initprot = initprot,
1675	1618	}),
1676	1619	});
1677		self.header_dirty = true;
1678	1620	self.load_commands_dirty = true;
1679	1621	}
1680	1622	if (self.got_section_index == null) {
...	...	@@ -1695,7 +1637,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1695	1637	.@"align" = 3, // 2^3 = @sizeOf(u64)
1696	1638	.flags = flags,
1697	1639	});
1698		self.header_dirty = true;
1699	1640	self.load_commands_dirty = true;
1700	1641	}
1701	1642	if (self.data_segment_cmd_index == null) {
...	...	@@ -1719,7 +1660,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1719	1660	.initprot = initprot,
1720	1661	}),
1721	1662	});
1722		self.header_dirty = true;
1723	1663	self.load_commands_dirty = true;
1724	1664	}
1725	1665	if (self.la_symbol_ptr_section_index == null) {
...	...	@@ -1740,7 +1680,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1740	1680	.@"align" = 3, // 2^3 = @sizeOf(u64)
1741	1681	.flags = flags,
1742	1682	});
1743		self.header_dirty = true;
1744	1683	self.load_commands_dirty = true;
1745	1684	}
1746	1685	if (self.data_section_index == null) {
...	...	@@ -1759,7 +1698,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1759	1698	.offset = @intCast(u32, off),
1760	1699	.@"align" = 3, // 2^3 = @sizeOf(u64)
1761	1700	});
1762		self.header_dirty = true;
1763	1701	self.load_commands_dirty = true;
1764	1702	}
1765	1703	if (self.linkedit_segment_cmd_index == null) {
...	...	@@ -1779,7 +1717,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1779	1717	.initprot = initprot,
1780	1718	}),
1781	1719	});
1782		self.header_dirty = true;
1783	1720	self.load_commands_dirty = true;
1784	1721	}
1785	1722	if (self.dyld_info_cmd_index == null) {
...	...	@@ -1826,7 +1763,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1826	1763	dyld.export_off = @intCast(u32, export_off);
1827	1764	dyld.export_size = expected_size;
1828	1765
1829		self.header_dirty = true;
1830	1766	self.load_commands_dirty = true;
1831	1767	}
1832	1768	if (self.symtab_cmd_index == null) {
...	...	@@ -1858,7 +1794,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1858	1794	symtab.stroff = @intCast(u32, strtab_off);
1859	1795	symtab.strsize = @intCast(u32, strtab_size);
1860	1796
1861		self.header_dirty = true;
1862	1797	self.load_commands_dirty = true;
1863	1798	self.string_table_dirty = true;
1864	1799	}
...	...	@@ -1895,7 +1830,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1895	1830	.nlocrel = 0,
1896	1831	},
1897	1832	});
1898		self.header_dirty = true;
1899	1833	self.load_commands_dirty = true;
1900	1834	}
1901	1835	if (self.dylinker_cmd_index == null) {
...	...	@@ -1914,7 +1848,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1914	1848	mem.set(u8, dylinker_cmd.data, 0);
1915	1849	mem.copy(u8, dylinker_cmd.data, mem.spanZ(DEFAULT_DYLD_PATH));
1916	1850	try self.load_commands.append(self.base.allocator, .{ .Dylinker = dylinker_cmd });
1917		self.header_dirty = true;
1918	1851	self.load_commands_dirty = true;
1919	1852	}
1920	1853	if (self.libsystem_cmd_index == null) {
...	...	@@ -1925,7 +1858,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1925	1858
1926	1859	try self.load_commands.append(self.base.allocator, .{ .Dylib = dylib_cmd });
1927	1860
1928		self.header_dirty = true;
1929	1861	self.load_commands_dirty = true;
1930	1862	}
1931	1863	if (self.main_cmd_index == null) {
...	...	@@ -1938,7 +1870,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1938	1870	.stacksize = 0,
1939	1871	},
1940	1872	});
1941		self.header_dirty = true;
1942	1873	self.load_commands_dirty = true;
1943	1874	}
1944	1875	if (self.version_min_cmd_index == null) {
...	...	@@ -1960,7 +1891,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1960	1891	.sdk = version,
1961	1892	},
1962	1893	});
1963		self.header_dirty = true;
1964	1894	self.load_commands_dirty = true;
1965	1895	}
1966	1896	if (self.source_version_cmd_index == null) {
...	...	@@ -1972,7 +1902,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1972	1902	.version = 0x0,
1973	1903	},
1974	1904	});
1975		self.header_dirty = true;
1976	1905	self.load_commands_dirty = true;
1977	1906	}
1978	1907	if (self.uuid_cmd_index == null) {
...	...	@@ -1984,7 +1913,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1984	1913	};
1985	1914	std.crypto.random.bytes(&uuid_cmd.uuid);
1986	1915	try self.load_commands.append(self.base.allocator, .{ .Uuid = uuid_cmd });
1987		self.header_dirty = true;
1988	1916	self.load_commands_dirty = true;
1989	1917	}
1990	1918	if (self.code_signature_cmd_index == null) {
...	...	@@ -1997,7 +1925,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
1997	1925	.datasize = 0,
1998	1926	},
1999	1927	});
2000		self.header_dirty = true;
2001	1928	self.load_commands_dirty = true;
2002	1929	}
2003	1930	if (!self.nonlazy_imports.contains("dyld_stub_binder")) {
...	...	@@ -3224,24 +3151,57 @@ fn writeLoadCommands(self: *MachO) !void {
3224	3151	}
3225	3152
3226	3153	const off = @sizeOf(macho.mach_header_64);
	3154
3227	3155	log.debug("writing {} load commands from 0x{x} to 0x{x}", .{ self.load_commands.items.len, off, off + sizeofcmds });
	3156
3228	3157	try self.base.file.?.pwriteAll(buffer, off);
3229	3158	self.load_commands_dirty = false;
3230	3159	}
3231	3160
3232	3161	/// Writes Mach-O file header.
3233	3162	fn writeHeader(self: *MachO) !void {
3234		if (!self.header_dirty) return;
	3163	var header = emptyHeader(.{
	3164	.flags = macho.MH_NOUNDEFS \| macho.MH_DYLDLINK \| macho.MH_PIE \| macho.MH_TWOLEVEL,
	3165	});
	3166
	3167	switch (self.base.options.target.cpu.arch) {
	3168	.aarch64 => {
	3169	header.cputype = macho.CPU_TYPE_ARM64;
	3170	header.cpusubtype = macho.CPU_SUBTYPE_ARM_ALL;
	3171	},
	3172	.x86_64 => {
	3173	header.cputype = macho.CPU_TYPE_X86_64;
	3174	header.cpusubtype = macho.CPU_SUBTYPE_X86_64_ALL;
	3175	},
	3176	else => return error.UnsupportedCpuArchitecture,
	3177	}
	3178
	3179	switch (self.base.options.output_mode) {
	3180	.Exe => {
	3181	header.filetype = macho.MH_EXECUTE;
	3182	},
	3183	.Lib => {
	3184	// By this point, it can only be a dylib.
	3185	header.filetype = macho.MH_DYLIB;
	3186	header.flags \|= macho.MH_NO_REEXPORTED_DYLIBS;
	3187	},
	3188	else => unreachable,
	3189	}
	3190
	3191	if (self.hasTlvDescriptors()) {
	3192	header.flags \|= macho.MH_HAS_TLV_DESCRIPTORS;
	3193	}
	3194
	3195	header.ncmds = @intCast(u32, self.load_commands.items.len);
	3196	header.sizeofcmds = 0;
3235	3197
3236		self.header.?.ncmds = @intCast(u32, self.load_commands.items.len);
3237		var sizeofcmds: u32 = 0;
3238	3198	for (self.load_commands.items) \|cmd\| {
3239		sizeofcmds += cmd.cmdsize();
	3199	header.sizeofcmds += cmd.cmdsize();
3240	3200	}
3241		self.header.?.sizeofcmds = sizeofcmds;
3242		log.debug("writing Mach-O header {}", .{self.header.?});
3243		try self.base.file.?.pwriteAll(mem.asBytes(&self.header.?), 0);
3244		self.header_dirty = false;
	3201
	3202	log.debug("writing Mach-O header {}", .{header});
	3203
	3204	try self.base.file.?.pwriteAll(mem.asBytes(&header), 0);
3245	3205	}
3246	3206
3247	3207	pub fn padToIdeal(actual_size: anytype) @TypeOf(actual_size) {
...	...	@@ -3249,3 +3209,7 @@ pub fn padToIdeal(actual_size: anytype) @TypeOf(actual_size) {
3249	3209	return std.math.add(@TypeOf(actual_size), actual_size, actual_size / ideal_factor) catch
3250	3210	std.math.maxInt(@TypeOf(actual_size));
3251	3211	}
	3212
	3213	fn hasTlvDescriptors(_: *MachO) bool {
	3214	return false;
	3215	}

src/link/MachO/DebugSymbols.zig+35-53

...	...	@@ -3,7 +3,7 @@ const DebugSymbols = @This();
3	3	const std = @import("std");
4	4	const assert = std.debug.assert;
5	5	const fs = std.fs;
6		const log = std.log.scoped(.link);
	6	const log = std.log.scoped(.dsym);
7	7	const macho = std.macho;
8	8	const mem = std.mem;
9	9	const DW = std.dwarf;
...	...	@@ -27,9 +27,6 @@ const page_size: u16 = 0x1000;
27	27	base: *MachO,
28	28	file: fs.File,
29	29
30		/// Mach header
31		header: ?macho.mach_header_64 = null,
32
33	30	/// Table of all load commands
34	31	load_commands: std.ArrayListUnmanaged(LoadCommand) = .{},
35	32	/// __PAGEZERO segment
...	...	@@ -78,7 +75,6 @@ dbg_info_decl_last: ?*TextBlock = null,
78	75	/// Table of debug symbol names aka the debug string table.
79	76	debug_string_table: std.ArrayListUnmanaged(u8) = .{},
80	77
81		header_dirty: bool = false,
82	78	load_commands_dirty: bool = false,
83	79	string_table_dirty: bool = false,
84	80	debug_string_table_dirty: bool = false,
...	...	@@ -106,26 +102,10 @@ const min_nop_size = 2;
106	102	/// You must call this function after `MachO.populateMissingMetadata()`
107	103	/// has been called to get a viable debug symbols output.
108	104	pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void {
109		if (self.header == null) {
110		const base_header = self.base.header.?;
111		var header: macho.mach_header_64 = undefined;
112		header.magic = macho.MH_MAGIC_64;
113		header.cputype = base_header.cputype;
114		header.cpusubtype = base_header.cpusubtype;
115		header.filetype = macho.MH_DSYM;
116		// These will get populated at the end of flushing the results to file.
117		header.ncmds = 0;
118		header.sizeofcmds = 0;
119		header.flags = 0;
120		header.reserved = 0;
121		self.header = header;
122		self.header_dirty = true;
123		}
124	105	if (self.uuid_cmd_index == null) {
125	106	const base_cmd = self.base.load_commands.items[self.base.uuid_cmd_index.?];
126	107	self.uuid_cmd_index = @intCast(u16, self.load_commands.items.len);
127	108	try self.load_commands.append(allocator, base_cmd);
128		self.header_dirty = true;
129	109	self.load_commands_dirty = true;
130	110	}
131	111	if (self.symtab_cmd_index == null) {
...	...	@@ -134,11 +114,11 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
134	114	const symtab_size = base_cmd.nsyms * @sizeOf(macho.nlist_64);
135	115	const symtab_off = self.findFreeSpaceLinkedit(symtab_size, @sizeOf(macho.nlist_64));
136	116
137		log.debug("found dSym symbol table free space 0x{x} to 0x{x}", .{ symtab_off, symtab_off + symtab_size });
	117	log.debug("found symbol table free space 0x{x} to 0x{x}", .{ symtab_off, symtab_off + symtab_size });
138	118
139	119	const strtab_off = self.findFreeSpaceLinkedit(base_cmd.strsize, 1);
140	120
141		log.debug("found dSym string table free space 0x{x} to 0x{x}", .{ strtab_off, strtab_off + base_cmd.strsize });
	121	log.debug("found string table free space 0x{x} to 0x{x}", .{ strtab_off, strtab_off + base_cmd.strsize });
142	122
143	123	try self.load_commands.append(allocator, .{
144	124	.Symtab = .{
...	...	@@ -150,7 +130,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
150	130	.strsize = base_cmd.strsize,
151	131	},
152	132	});
153		self.header_dirty = true;
154	133	self.load_commands_dirty = true;
155	134	self.string_table_dirty = true;
156	135	}
...	...	@@ -159,7 +138,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
159	138	const base_cmd = self.base.load_commands.items[self.base.pagezero_segment_cmd_index.?].Segment;
160	139	const cmd = try self.copySegmentCommand(allocator, base_cmd);
161	140	try self.load_commands.append(allocator, .{ .Segment = cmd });
162		self.header_dirty = true;
163	141	self.load_commands_dirty = true;
164	142	}
165	143	if (self.text_segment_cmd_index == null) {
...	...	@@ -167,7 +145,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
167	145	const base_cmd = self.base.load_commands.items[self.base.text_segment_cmd_index.?].Segment;
168	146	const cmd = try self.copySegmentCommand(allocator, base_cmd);
169	147	try self.load_commands.append(allocator, .{ .Segment = cmd });
170		self.header_dirty = true;
171	148	self.load_commands_dirty = true;
172	149	}
173	150	if (self.data_const_segment_cmd_index == null) outer: {
...	...	@@ -176,7 +153,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
176	153	const base_cmd = self.base.load_commands.items[self.base.data_const_segment_cmd_index.?].Segment;
177	154	const cmd = try self.copySegmentCommand(allocator, base_cmd);
178	155	try self.load_commands.append(allocator, .{ .Segment = cmd });
179		self.header_dirty = true;
180	156	self.load_commands_dirty = true;
181	157	}
182	158	if (self.data_segment_cmd_index == null) outer: {
...	...	@@ -185,7 +161,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
185	161	const base_cmd = self.base.load_commands.items[self.base.data_segment_cmd_index.?].Segment;
186	162	const cmd = try self.copySegmentCommand(allocator, base_cmd);
187	163	try self.load_commands.append(allocator, .{ .Segment = cmd });
188		self.header_dirty = true;
189	164	self.load_commands_dirty = true;
190	165	}
191	166	if (self.linkedit_segment_cmd_index == null) {
...	...	@@ -196,7 +171,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
196	171	cmd.inner.fileoff = self.linkedit_off;
197	172	cmd.inner.filesize = self.linkedit_size;
198	173	try self.load_commands.append(allocator, .{ .Segment = cmd });
199		self.header_dirty = true;
200	174	self.load_commands_dirty = true;
201	175	}
202	176	if (self.dwarf_segment_cmd_index == null) {
...	...	@@ -208,7 +182,7 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
208	182	const off = linkedit.inner.fileoff + linkedit.inner.filesize;
209	183	const vmaddr = linkedit.inner.vmaddr + linkedit.inner.vmsize;
210	184
211		log.debug("found dSym __DWARF segment free space 0x{x} to 0x{x}", .{ off, off + needed_size });
	185	log.debug("found __DWARF segment free space 0x{x} to 0x{x}", .{ off, off + needed_size });
212	186
213	187	try self.load_commands.append(allocator, .{
214	188	.Segment = SegmentCommand.empty("__DWARF", .{
...	...	@@ -218,7 +192,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
218	192	.filesize = needed_size,
219	193	}),
220	194	});
221		self.header_dirty = true;
222	195	self.load_commands_dirty = true;
223	196	}
224	197	if (self.debug_str_section_index == null) {
...	...	@@ -232,7 +205,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
232	205	.offset = @intCast(u32, dwarf_segment.inner.fileoff),
233	206	.@"align" = 1,
234	207	});
235		self.header_dirty = true;
236	208	self.load_commands_dirty = true;
237	209	self.debug_string_table_dirty = true;
238	210	}
...	...	@@ -244,7 +216,7 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
244	216	const p_align = 1;
245	217	const off = dwarf_segment.findFreeSpace(file_size_hint, p_align, null);
246	218
247		log.debug("found dSym __debug_info free space 0x{x} to 0x{x}", .{ off, off + file_size_hint });
	219	log.debug("found __debug_info free space 0x{x} to 0x{x}", .{ off, off + file_size_hint });
248	220
249	221	try dwarf_segment.addSection(allocator, "__debug_info", .{
250	222	.addr = dwarf_segment.inner.vmaddr + off - dwarf_segment.inner.fileoff,
...	...	@@ -252,7 +224,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
252	224	.offset = @intCast(u32, off),
253	225	.@"align" = p_align,
254	226	});
255		self.header_dirty = true;
256	227	self.load_commands_dirty = true;
257	228	self.debug_info_header_dirty = true;
258	229	}
...	...	@@ -264,7 +235,7 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
264	235	const p_align = 1;
265	236	const off = dwarf_segment.findFreeSpace(file_size_hint, p_align, null);
266	237
267		log.debug("found dSym __debug_abbrev free space 0x{x} to 0x{x}", .{ off, off + file_size_hint });
	238	log.debug("found __debug_abbrev free space 0x{x} to 0x{x}", .{ off, off + file_size_hint });
268	239
269	240	try dwarf_segment.addSection(allocator, "__debug_abbrev", .{
270	241	.addr = dwarf_segment.inner.vmaddr + off - dwarf_segment.inner.fileoff,
...	...	@@ -272,7 +243,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
272	243	.offset = @intCast(u32, off),
273	244	.@"align" = p_align,
274	245	});
275		self.header_dirty = true;
276	246	self.load_commands_dirty = true;
277	247	self.debug_abbrev_section_dirty = true;
278	248	}
...	...	@@ -284,7 +254,7 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
284	254	const p_align = 16;
285	255	const off = dwarf_segment.findFreeSpace(file_size_hint, p_align, null);
286	256
287		log.debug("found dSym __debug_aranges free space 0x{x} to 0x{x}", .{ off, off + file_size_hint });
	257	log.debug("found __debug_aranges free space 0x{x} to 0x{x}", .{ off, off + file_size_hint });
288	258
289	259	try dwarf_segment.addSection(allocator, "__debug_aranges", .{
290	260	.addr = dwarf_segment.inner.vmaddr + off - dwarf_segment.inner.fileoff,
...	...	@@ -292,7 +262,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
292	262	.offset = @intCast(u32, off),
293	263	.@"align" = p_align,
294	264	});
295		self.header_dirty = true;
296	265	self.load_commands_dirty = true;
297	266	self.debug_aranges_section_dirty = true;
298	267	}
...	...	@@ -304,7 +273,7 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
304	273	const p_align = 1;
305	274	const off = dwarf_segment.findFreeSpace(file_size_hint, p_align, null);
306	275
307		log.debug("found dSym __debug_line free space 0x{x} to 0x{x}", .{ off, off + file_size_hint });
	276	log.debug("found __debug_line free space 0x{x} to 0x{x}", .{ off, off + file_size_hint });
308	277
309	278	try dwarf_segment.addSection(allocator, "__debug_line", .{
310	279	.addr = dwarf_segment.inner.vmaddr + off - dwarf_segment.inner.fileoff,
...	...	@@ -312,7 +281,6 @@ pub fn populateMissingMetadata(self: DebugSymbols, allocator: Allocator) !void
312	281	.offset = @intCast(u32, off),
313	282	.@"align" = p_align,
314	283	});
315		self.header_dirty = true;
316	284	self.load_commands_dirty = true;
317	285	self.debug_line_header_dirty = true;
318	286	}
...	...	@@ -624,7 +592,6 @@ pub fn flushModule(self: DebugSymbols, allocator: Allocator, options: link.Opt
624	592	try self.writeLoadCommands(allocator);
625	593	try self.writeHeader();
626	594
627		assert(!self.header_dirty);
628	595	assert(!self.load_commands_dirty);
629	596	assert(!self.string_table_dirty);
630	597	assert(!self.debug_abbrev_section_dirty);
...	...	@@ -716,23 +683,38 @@ fn writeLoadCommands(self: DebugSymbols, allocator: Allocator) !void {
716	683	}
717	684
718	685	const off = @sizeOf(macho.mach_header_64);
719		log.debug("writing {} dSym load commands from 0x{x} to 0x{x}", .{ self.load_commands.items.len, off, off + sizeofcmds });
	686	log.debug("writing {} load commands from 0x{x} to 0x{x}", .{ self.load_commands.items.len, off, off + sizeofcmds });
720	687	try self.file.pwriteAll(buffer, off);
721	688	self.load_commands_dirty = false;
722	689	}
723	690
724	691	fn writeHeader(self: *DebugSymbols) !void {
725		if (!self.header_dirty) return;
	692	var header = emptyHeader(.{
	693	.filetype = macho.MH_DSYM,
	694	});
	695
	696	switch (self.base.base.options.target.cpu.arch) {
	697	.aarch64 => {
	698	header.cputype = macho.CPU_TYPE_ARM64;
	699	header.cpusubtype = macho.CPU_SUBTYPE_ARM_ALL;
	700	},
	701	.x86_64 => {
	702	header.cputype = macho.CPU_TYPE_X86_64;
	703	header.cpusubtype = macho.CPU_SUBTYPE_X86_64_ALL;
	704	},
	705	else => return error.UnsupportedCpuArchitecture,
	706	}
	707
	708	header.ncmds = @intCast(u32, self.load_commands.items.len);
	709	header.sizeofcmds = 0;
726	710
727		self.header.?.ncmds = @intCast(u32, self.load_commands.items.len);
728		var sizeofcmds: u32 = 0;
729	711	for (self.load_commands.items) \|cmd\| {
730		sizeofcmds += cmd.cmdsize();
	712	header.sizeofcmds += cmd.cmdsize();
731	713	}
732		self.header.?.sizeofcmds = sizeofcmds;
733		log.debug("writing Mach-O dSym header {}", .{self.header.?});
734		try self.file.pwriteAll(mem.asBytes(&self.header.?), 0);
735		self.header_dirty = false;
	714
	715	log.debug("writing Mach-O header {}", .{header});
	716
	717	try self.file.pwriteAll(mem.asBytes(&header), 0);
736	718	}
737	719
738	720	fn allocatedSizeLinkedit(self: *DebugSymbols, start: u64) u64 {
...	...	@@ -798,7 +780,7 @@ fn relocateSymbolTable(self: *DebugSymbols) !void {
798	780	const existing_size = symtab.nsyms * @sizeOf(macho.nlist_64);
799	781
800	782	assert(new_symoff + existing_size <= self.linkedit_off + self.linkedit_size); // TODO expand LINKEDIT segment.
801		log.debug("relocating dSym symbol table from 0x{x}-0x{x} to 0x{x}-0x{x}", .{
	783	log.debug("relocating symbol table from 0x{x}-0x{x} to 0x{x}-0x{x}", .{
802	784	symtab.symoff,
803	785	symtab.symoff + existing_size,
804	786	new_symoff,
...	...	@@ -820,7 +802,7 @@ pub fn writeLocalSymbol(self: *DebugSymbols, index: usize) !void {
820	802	try self.relocateSymbolTable();
821	803	const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
822	804	const off = symtab.symoff + @sizeOf(macho.nlist_64) * index;
823		log.debug("writing dSym local symbol {} at 0x{x}", .{ index, off });
	805	log.debug("writing local symbol {} at 0x{x}", .{ index, off });
824	806	try self.file.pwriteAll(mem.asBytes(&self.base.locals.items[index]), off);
825	807	}
826	808
...	...	@@ -839,7 +821,7 @@ fn writeStringTable(self: *DebugSymbols) !void {
839	821	symtab.stroff = @intCast(u32, self.findFreeSpaceLinkedit(needed_size, 1));
840	822	}
841	823	symtab.strsize = @intCast(u32, needed_size);
842		log.debug("writing dSym string table from 0x{x} to 0x{x}", .{ symtab.stroff, symtab.stroff + symtab.strsize });
	824	log.debug("writing string table from 0x{x} to 0x{x}", .{ symtab.stroff, symtab.stroff + symtab.strsize });
843	825
844	826	try self.file.pwriteAll(self.base.string_table.items, symtab.stroff);
845	827	self.load_commands_dirty = true;

src/link/MachO/Zld.zig+15-25

...	...	@@ -3132,54 +3132,44 @@ fn writeLoadCommands(self: *Zld) !void {
3132	3132	}
3133	3133
3134	3134	fn writeHeader(self: *Zld) !void {
3135		var header: macho.mach_header_64 = undefined;
3136		header.magic = macho.MH_MAGIC_64;
3137
3138		const CpuInfo = struct {
3139		cpu_type: macho.cpu_type_t,
3140		cpu_subtype: macho.cpu_subtype_t,
3141		};
	3135	var header = emptyHeader(.{
	3136	.flags = macho.MH_NOUNDEFS \| macho.MH_DYLDLINK \| macho.MH_PIE \| macho.MH_TWOLEVEL,
	3137	});
3142	3138
3143		const cpu_info: CpuInfo = switch (self.target.?.cpu.arch) {
3144		.aarch64 => .{
3145		.cpu_type = macho.CPU_TYPE_ARM64,
3146		.cpu_subtype = macho.CPU_SUBTYPE_ARM_ALL,
	3139	switch (self.target.?.cpu.arch) {
	3140	.aarch64 => {
	3141	header.cputype = macho.CPU_TYPE_ARM64;
	3142	header.cpusubtype = macho.CPU_SUBTYPE_ARM_ALL;
3147	3143	},
3148		.x86_64 => .{
3149		.cpu_type = macho.CPU_TYPE_X86_64,
3150		.cpu_subtype = macho.CPU_SUBTYPE_X86_64_ALL,
	3144	.x86_64 => {
	3145	header.cputype = macho.CPU_TYPE_X86_64;
	3146	header.cpusubtype = macho.CPU_SUBTYPE_X86_64_ALL;
3151	3147	},
3152	3148	else => return error.UnsupportedCpuArchitecture,
3153		};
3154		header.cputype = cpu_info.cpu_type;
3155		header.cpusubtype = cpu_info.cpu_subtype;
	3149	}
3156	3150
3157	3151	switch (self.output.?.tag) {
3158	3152	.exe => {
3159	3153	header.filetype = macho.MH_EXECUTE;
3160		header.flags = macho.MH_NOUNDEFS \| macho.MH_DYLDLINK \| macho.MH_PIE \| macho.MH_TWOLEVEL;
3161	3154	},
3162	3155	.dylib => {
3163	3156	header.filetype = macho.MH_DYLIB;
3164		header.flags = macho.MH_NOUNDEFS \|
3165		macho.MH_DYLDLINK \|
3166		macho.MH_PIE \|
3167		macho.MH_TWOLEVEL \|
3168		macho.MH_NO_REEXPORTED_DYLIBS;
	3157	header.flags \|= macho.MH_NO_REEXPORTED_DYLIBS;
3169	3158	},
3170	3159	}
3171	3160
3172		header.reserved = 0;
3173
3174	3161	if (self.tlv_section_index) \|_\|
3175	3162	header.flags \|= macho.MH_HAS_TLV_DESCRIPTORS;
3176	3163
3177	3164	header.ncmds = @intCast(u32, self.load_commands.items.len);
3178	3165	header.sizeofcmds = 0;
	3166
3179	3167	for (self.load_commands.items) \|cmd\| {
3180	3168	header.sizeofcmds += cmd.cmdsize();
3181	3169	}
	3170
3182	3171	log.debug("writing Mach-O header {}", .{header});
	3172
3183	3173	try self.file.?.pwriteAll(mem.asBytes(&header), 0);
3184	3174	}
3185	3175

src/link/MachO/commands.zig+22

...	...	@@ -11,6 +11,28 @@ const Allocator = std.mem.Allocator;
11	11	const MachO = @import("../MachO.zig");
12	12	const padToIdeal = MachO.padToIdeal;
13	13
	14	pub const HeaderArgs = struct {
	15	magic: u32 = macho.MH_MAGIC_64,
	16	cputype: macho.cpu_type_t = 0,
	17	cpusubtype: macho.cpu_subtype_t = 0,
	18	filetype: u32 = 0,
	19	flags: u32 = 0,
	20	reserved: u32 = 0,
	21	};
	22
	23	pub fn emptyHeader(args: HeaderArgs) macho.mach_header_64 {
	24	return .{
	25	.magic = args.magic,
	26	.cputype = args.cputype,
	27	.cpusubtype = args.cpusubtype,
	28	.filetype = args.filetype,
	29	.ncmds = 0,
	30	.sizeofcmds = 0,
	31	.flags = args.flags,
	32	.reserved = args.reserved,
	33	};
	34	}
	35
14	36	pub const LoadCommand = union(enum) {
15	37	Segment: SegmentCommand,
16	38	DyldInfoOnly: macho.dyld_info_command,