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| 1 | const Zld = @This(); |
| 2 | |
| 3 | const std = @import("std"); |
| 4 | const assert = std.debug.assert; |
| 5 | const dwarf = std.dwarf; |
| 6 | const leb = std.leb; |
| 7 | const mem = std.mem; |
| 8 | const meta = std.meta; |
| 9 | const fs = std.fs; |
| 10 | const macho = std.macho; |
| 11 | const math = std.math; |
| 12 | const log = std.log.scoped(.zld); |
| 13 | |
| 14 | const Allocator = mem.Allocator; |
| 15 | const CodeSignature = @import("CodeSignature.zig"); |
| 16 | const Archive = @import("Archive.zig"); |
| 17 | const Object = @import("Object.zig"); |
| 18 | const Trie = @import("Trie.zig"); |
| 19 | |
| 20 | usingnamespace @import("commands.zig"); |
| 21 | usingnamespace @import("bind.zig"); |
| 22 | usingnamespace @import("reloc.zig"); |
| 23 | |
| 24 | allocator: *Allocator, |
| 25 | |
| 26 | arch: ?std.Target.Cpu.Arch = null, |
| 27 | page_size: ?u16 = null, |
| 28 | file: ?fs.File = null, |
| 29 | out_path: ?[]const u8 = null, |
| 30 | |
| 31 | // TODO Eventually, we will want to keep track of the archives themselves to be able to exclude objects |
| 32 | // contained within from landing in the final artifact. For now however, since we don't optimise the binary |
| 33 | // at all, we just move all objects from the archives into the final artifact. |
| 34 | objects: std.ArrayListUnmanaged(Object) = .{}, |
| 35 | |
| 36 | load_commands: std.ArrayListUnmanaged(LoadCommand) = .{}, |
| 37 | |
| 38 | pagezero_segment_cmd_index: ?u16 = null, |
| 39 | text_segment_cmd_index: ?u16 = null, |
| 40 | data_segment_cmd_index: ?u16 = null, |
| 41 | linkedit_segment_cmd_index: ?u16 = null, |
| 42 | dyld_info_cmd_index: ?u16 = null, |
| 43 | symtab_cmd_index: ?u16 = null, |
| 44 | dysymtab_cmd_index: ?u16 = null, |
| 45 | dylinker_cmd_index: ?u16 = null, |
| 46 | libsystem_cmd_index: ?u16 = null, |
| 47 | data_in_code_cmd_index: ?u16 = null, |
| 48 | function_starts_cmd_index: ?u16 = null, |
| 49 | main_cmd_index: ?u16 = null, |
| 50 | version_min_cmd_index: ?u16 = null, |
| 51 | source_version_cmd_index: ?u16 = null, |
| 52 | uuid_cmd_index: ?u16 = null, |
| 53 | code_signature_cmd_index: ?u16 = null, |
| 54 | |
| 55 | text_section_index: ?u16 = null, |
| 56 | stubs_section_index: ?u16 = null, |
| 57 | stub_helper_section_index: ?u16 = null, |
| 58 | got_section_index: ?u16 = null, |
| 59 | tlv_section_index: ?u16 = null, |
| 60 | la_symbol_ptr_section_index: ?u16 = null, |
| 61 | data_section_index: ?u16 = null, |
| 62 | |
| 63 | locals: std.StringArrayHashMapUnmanaged(macho.nlist_64) = .{}, |
| 64 | exports: std.StringArrayHashMapUnmanaged(macho.nlist_64) = .{}, |
| 65 | nonlazy_imports: std.StringArrayHashMapUnmanaged(Import) = .{}, |
| 66 | lazy_imports: std.StringArrayHashMapUnmanaged(Import) = .{}, |
| 67 | threadlocal_imports: std.StringArrayHashMapUnmanaged(Import) = .{}, |
| 68 | local_rebases: std.ArrayListUnmanaged(Pointer) = .{}, |
| 69 | |
| 70 | strtab: std.ArrayListUnmanaged(u8) = .{}, |
| 71 | |
| 72 | stub_helper_stubs_start_off: ?u64 = null, |
| 73 | |
| 74 | segments_directory: std.AutoHashMapUnmanaged([16]u8, u16) = .{}, |
| 75 | directory: std.AutoHashMapUnmanaged(DirectoryKey, DirectoryEntry) = .{}, |
| 76 | |
| 77 | const DirectoryKey = struct { |
| 78 | segname: [16]u8, |
| 79 | sectname: [16]u8, |
| 80 | }; |
| 81 | |
| 82 | const DirectoryEntry = struct { |
| 83 | seg_index: u16, |
| 84 | sect_index: u16, |
| 85 | }; |
| 86 | |
| 87 | const DebugInfo = struct { |
| 88 | inner: dwarf.DwarfInfo, |
| 89 | debug_info: []u8, |
| 90 | debug_abbrev: []u8, |
| 91 | debug_str: []u8, |
| 92 | debug_line: []u8, |
| 93 | debug_ranges: []u8, |
| 94 | |
| 95 | pub fn parseFromObject(allocator: *Allocator, object: Object) !?DebugInfo { |
| 96 | var debug_info = blk: { |
| 97 | const index = object.dwarf_debug_info_index orelse return null; |
| 98 | break :blk try object.readSection(allocator, index); |
| 99 | }; |
| 100 | var debug_abbrev = blk: { |
| 101 | const index = object.dwarf_debug_abbrev_index orelse return null; |
| 102 | break :blk try object.readSection(allocator, index); |
| 103 | }; |
| 104 | var debug_str = blk: { |
| 105 | const index = object.dwarf_debug_str_index orelse return null; |
| 106 | break :blk try object.readSection(allocator, index); |
| 107 | }; |
| 108 | var debug_line = blk: { |
| 109 | const index = object.dwarf_debug_line_index orelse return null; |
| 110 | break :blk try object.readSection(allocator, index); |
| 111 | }; |
| 112 | var debug_ranges = blk: { |
| 113 | if (object.dwarf_debug_ranges_index) |ind| { |
| 114 | break :blk try object.readSection(allocator, ind); |
| 115 | } |
| 116 | break :blk try allocator.alloc(u8, 0); |
| 117 | }; |
| 118 | |
| 119 | var inner: dwarf.DwarfInfo = .{ |
| 120 | .endian = .Little, |
| 121 | .debug_info = debug_info, |
| 122 | .debug_abbrev = debug_abbrev, |
| 123 | .debug_str = debug_str, |
| 124 | .debug_line = debug_line, |
| 125 | .debug_ranges = debug_ranges, |
| 126 | }; |
| 127 | try dwarf.openDwarfDebugInfo(&inner, allocator); |
| 128 | |
| 129 | return DebugInfo{ |
| 130 | .inner = inner, |
| 131 | .debug_info = debug_info, |
| 132 | .debug_abbrev = debug_abbrev, |
| 133 | .debug_str = debug_str, |
| 134 | .debug_line = debug_line, |
| 135 | .debug_ranges = debug_ranges, |
| 136 | }; |
| 137 | } |
| 138 | |
| 139 | pub fn deinit(self: *DebugInfo, allocator: *Allocator) void { |
| 140 | allocator.free(self.debug_info); |
| 141 | allocator.free(self.debug_abbrev); |
| 142 | allocator.free(self.debug_str); |
| 143 | allocator.free(self.debug_line); |
| 144 | allocator.free(self.debug_ranges); |
| 145 | self.inner.abbrev_table_list.deinit(); |
| 146 | self.inner.compile_unit_list.deinit(); |
| 147 | self.inner.func_list.deinit(); |
| 148 | } |
| 149 | }; |
| 150 | |
| 151 | pub const Import = struct { |
| 152 | /// MachO symbol table entry. |
| 153 | symbol: macho.nlist_64, |
| 154 | |
| 155 | /// Id of the dynamic library where the specified entries can be found. |
| 156 | dylib_ordinal: i64, |
| 157 | |
| 158 | /// Index of this import within the import list. |
| 159 | index: u32, |
| 160 | }; |
| 161 | |
| 162 | /// Default path to dyld |
| 163 | /// TODO instead of hardcoding it, we should probably look through some env vars and search paths |
| 164 | /// instead but this will do for now. |
| 165 | const DEFAULT_DYLD_PATH: [*:0]const u8 = "/usr/lib/dyld"; |
| 166 | |
| 167 | /// Default lib search path |
| 168 | /// TODO instead of hardcoding it, we should probably look through some env vars and search paths |
| 169 | /// instead but this will do for now. |
| 170 | const DEFAULT_LIB_SEARCH_PATH: []const u8 = "/usr/lib"; |
| 171 | |
| 172 | const LIB_SYSTEM_NAME: [*:0]const u8 = "System"; |
| 173 | /// TODO we should search for libSystem and fail if it doesn't exist, instead of hardcoding it |
| 174 | const LIB_SYSTEM_PATH: [*:0]const u8 = DEFAULT_LIB_SEARCH_PATH ++ "/libSystem.B.dylib"; |
| 175 | |
| 176 | pub fn init(allocator: *Allocator) Zld { |
| 177 | return .{ .allocator = allocator }; |
| 178 | } |
| 179 | |
| 180 | pub fn deinit(self: *Zld) void { |
| 181 | self.strtab.deinit(self.allocator); |
| 182 | self.local_rebases.deinit(self.allocator); |
| 183 | for (self.lazy_imports.items()) |*entry| { |
| 184 | self.allocator.free(entry.key); |
| 185 | } |
| 186 | self.lazy_imports.deinit(self.allocator); |
| 187 | for (self.threadlocal_imports.items()) |*entry| { |
| 188 | self.allocator.free(entry.key); |
| 189 | } |
| 190 | self.threadlocal_imports.deinit(self.allocator); |
| 191 | for (self.nonlazy_imports.items()) |*entry| { |
| 192 | self.allocator.free(entry.key); |
| 193 | } |
| 194 | self.nonlazy_imports.deinit(self.allocator); |
| 195 | for (self.exports.items()) |*entry| { |
| 196 | self.allocator.free(entry.key); |
| 197 | } |
| 198 | self.exports.deinit(self.allocator); |
| 199 | for (self.locals.items()) |*entry| { |
| 200 | self.allocator.free(entry.key); |
| 201 | } |
| 202 | self.locals.deinit(self.allocator); |
| 203 | for (self.objects.items) |*object| { |
| 204 | object.deinit(); |
| 205 | } |
| 206 | self.objects.deinit(self.allocator); |
| 207 | for (self.load_commands.items) |*lc| { |
| 208 | lc.deinit(self.allocator); |
| 209 | } |
| 210 | self.load_commands.deinit(self.allocator); |
| 211 | self.segments_directory.deinit(self.allocator); |
| 212 | self.directory.deinit(self.allocator); |
| 213 | if (self.file) |*f| f.close(); |
| 214 | } |
| 215 | |
| 216 | pub fn link(self: *Zld, files: []const []const u8, out_path: []const u8) !void { |
| 217 | if (files.len == 0) return error.NoInputFiles; |
| 218 | if (out_path.len == 0) return error.EmptyOutputPath; |
| 219 | |
| 220 | if (self.arch == null) { |
| 221 | // Try inferring the arch from the object files. |
| 222 | self.arch = blk: { |
| 223 | const file = try fs.cwd().openFile(files[0], .{}); |
| 224 | defer file.close(); |
| 225 | var reader = file.reader(); |
| 226 | const header = try reader.readStruct(macho.mach_header_64); |
| 227 | const arch: std.Target.Cpu.Arch = switch (header.cputype) { |
| 228 | macho.CPU_TYPE_X86_64 => .x86_64, |
| 229 | macho.CPU_TYPE_ARM64 => .aarch64, |
| 230 | else => |value| { |
| 231 | log.err("unsupported cpu architecture 0x{x}", .{value}); |
| 232 | return error.UnsupportedCpuArchitecture; |
| 233 | }, |
| 234 | }; |
| 235 | break :blk arch; |
| 236 | }; |
| 237 | } |
| 238 | |
| 239 | self.page_size = switch (self.arch.?) { |
| 240 | .aarch64 => 0x4000, |
| 241 | .x86_64 => 0x1000, |
| 242 | else => unreachable, |
| 243 | }; |
| 244 | self.out_path = out_path; |
| 245 | self.file = try fs.cwd().createFile(out_path, .{ |
| 246 | .truncate = true, |
| 247 | .read = true, |
| 248 | .mode = if (std.Target.current.os.tag == .windows) 0 else 0o777, |
| 249 | }); |
| 250 | |
| 251 | try self.populateMetadata(); |
| 252 | try self.parseInputFiles(files); |
| 253 | try self.resolveImports(); |
| 254 | self.allocateTextSegment(); |
| 255 | self.allocateDataSegment(); |
| 256 | self.allocateLinkeditSegment(); |
| 257 | try self.writeStubHelperCommon(); |
| 258 | try self.resolveSymbols(); |
| 259 | try self.doRelocs(); |
| 260 | try self.flush(); |
| 261 | } |
| 262 | |
| 263 | fn parseInputFiles(self: *Zld, files: []const []const u8) !void { |
| 264 | for (files) |file_name| { |
| 265 | const file = try fs.cwd().openFile(file_name, .{}); |
| 266 | |
| 267 | try_object: { |
| 268 | var object = Object.initFromFile(self.allocator, self.arch.?, file_name, file) catch |err| switch (err) { |
| 269 | error.NotObject => break :try_object, |
| 270 | else => |e| return e, |
| 271 | }; |
| 272 | const index = self.objects.items.len; |
| 273 | try self.objects.append(self.allocator, object); |
| 274 | const p_object = &self.objects.items[index]; |
| 275 | try self.parseObjectFile(p_object); |
| 276 | continue; |
| 277 | } |
| 278 | |
| 279 | try_archive: { |
| 280 | var archive = Archive.initFromFile(self.allocator, self.arch.?, file_name, file) catch |err| switch (err) { |
| 281 | error.NotArchive => break :try_archive, |
| 282 | else => |e| return e, |
| 283 | }; |
| 284 | defer archive.deinit(); |
| 285 | while (archive.objects.popOrNull()) |object| { |
| 286 | const index = self.objects.items.len; |
| 287 | try self.objects.append(self.allocator, object); |
| 288 | const p_object = &self.objects.items[index]; |
| 289 | try self.parseObjectFile(p_object); |
| 290 | } |
| 291 | continue; |
| 292 | } |
| 293 | |
| 294 | log.err("unexpected file type: expected object '.o' or archive '.a': {s}", .{file_name}); |
| 295 | return error.UnexpectedInputFileType; |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | fn parseObjectFile(self: *Zld, object: *const Object) !void { |
| 300 | const seg_cmd = object.load_commands.items[object.segment_cmd_index.?].Segment; |
| 301 | for (seg_cmd.sections.items) |sect| { |
| 302 | const sectname = parseName(§.sectname); |
| 303 | |
| 304 | const seg_index = self.segments_directory.get(sect.segname) orelse { |
| 305 | log.info("segname {s} not found in the output artifact", .{sect.segname}); |
| 306 | continue; |
| 307 | }; |
| 308 | const seg = &self.load_commands.items[seg_index].Segment; |
| 309 | const res = try self.directory.getOrPut(self.allocator, .{ |
| 310 | .segname = sect.segname, |
| 311 | .sectname = sect.sectname, |
| 312 | }); |
| 313 | if (!res.found_existing) { |
| 314 | const sect_index = @intCast(u16, seg.sections.items.len); |
| 315 | if (mem.eql(u8, sectname, "__thread_vars")) { |
| 316 | self.tlv_section_index = sect_index; |
| 317 | } |
| 318 | try seg.append(self.allocator, .{ |
| 319 | .sectname = makeStaticString(§.sectname), |
| 320 | .segname = makeStaticString(§.segname), |
| 321 | .addr = 0, |
| 322 | .size = 0, |
| 323 | .offset = 0, |
| 324 | .@"align" = sect.@"align", |
| 325 | .reloff = 0, |
| 326 | .nreloc = 0, |
| 327 | .flags = sect.flags, |
| 328 | .reserved1 = 0, |
| 329 | .reserved2 = 0, |
| 330 | .reserved3 = 0, |
| 331 | }); |
| 332 | res.entry.value = .{ |
| 333 | .seg_index = seg_index, |
| 334 | .sect_index = sect_index, |
| 335 | }; |
| 336 | } |
| 337 | const dest_sect = &seg.sections.items[res.entry.value.sect_index]; |
| 338 | dest_sect.size += sect.size; |
| 339 | seg.inner.filesize += sect.size; |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | fn resolveImports(self: *Zld) !void { |
| 344 | var imports = std.StringArrayHashMap(bool).init(self.allocator); |
| 345 | defer imports.deinit(); |
| 346 | |
| 347 | for (self.objects.items) |object| { |
| 348 | for (object.symtab.items) |sym| { |
| 349 | if (isLocal(&sym)) continue; |
| 350 | |
| 351 | const name = object.getString(sym.n_strx); |
| 352 | const res = try imports.getOrPut(name); |
| 353 | if (isExport(&sym)) { |
| 354 | res.entry.value = false; |
| 355 | continue; |
| 356 | } |
| 357 | if (res.found_existing and !res.entry.value) |
| 358 | continue; |
| 359 | res.entry.value = true; |
| 360 | } |
| 361 | } |
| 362 | |
| 363 | for (imports.items()) |entry| { |
| 364 | if (!entry.value) continue; |
| 365 | |
| 366 | const sym_name = entry.key; |
| 367 | const n_strx = try self.makeString(sym_name); |
| 368 | var new_sym: macho.nlist_64 = .{ |
| 369 | .n_strx = n_strx, |
| 370 | .n_type = macho.N_UNDF | macho.N_EXT, |
| 371 | .n_value = 0, |
| 372 | .n_desc = macho.REFERENCE_FLAG_UNDEFINED_NON_LAZY | macho.N_SYMBOL_RESOLVER, |
| 373 | .n_sect = 0, |
| 374 | }; |
| 375 | var key = try self.allocator.dupe(u8, sym_name); |
| 376 | // TODO handle symbol resolution from non-libc dylibs. |
| 377 | const dylib_ordinal = 1; |
| 378 | |
| 379 | // TODO need to rework this. Perhaps should create a set of all possible libc |
| 380 | // symbols which are expected to be nonlazy? |
| 381 | if (mem.eql(u8, sym_name, "___stdoutp") or |
| 382 | mem.eql(u8, sym_name, "___stderrp") or |
| 383 | mem.eql(u8, sym_name, "___stdinp") or |
| 384 | mem.eql(u8, sym_name, "___stack_chk_guard") or |
| 385 | mem.eql(u8, sym_name, "_environ")) |
| 386 | { |
| 387 | log.debug("writing nonlazy symbol '{s}'", .{sym_name}); |
| 388 | const index = @intCast(u32, self.nonlazy_imports.items().len); |
| 389 | try self.nonlazy_imports.putNoClobber(self.allocator, key, .{ |
| 390 | .symbol = new_sym, |
| 391 | .dylib_ordinal = dylib_ordinal, |
| 392 | .index = index, |
| 393 | }); |
| 394 | } else if (mem.eql(u8, sym_name, "__tlv_bootstrap")) { |
| 395 | log.debug("writing threadlocal symbol '{s}'", .{sym_name}); |
| 396 | const index = @intCast(u32, self.threadlocal_imports.items().len); |
| 397 | try self.threadlocal_imports.putNoClobber(self.allocator, key, .{ |
| 398 | .symbol = new_sym, |
| 399 | .dylib_ordinal = dylib_ordinal, |
| 400 | .index = index, |
| 401 | }); |
| 402 | } else { |
| 403 | log.debug("writing lazy symbol '{s}'", .{sym_name}); |
| 404 | const index = @intCast(u32, self.lazy_imports.items().len); |
| 405 | try self.lazy_imports.putNoClobber(self.allocator, key, .{ |
| 406 | .symbol = new_sym, |
| 407 | .dylib_ordinal = dylib_ordinal, |
| 408 | .index = index, |
| 409 | }); |
| 410 | } |
| 411 | } |
| 412 | |
| 413 | const n_strx = try self.makeString("dyld_stub_binder"); |
| 414 | const name = try self.allocator.dupe(u8, "dyld_stub_binder"); |
| 415 | log.debug("writing nonlazy symbol 'dyld_stub_binder'", .{}); |
| 416 | const index = @intCast(u32, self.nonlazy_imports.items().len); |
| 417 | try self.nonlazy_imports.putNoClobber(self.allocator, name, .{ |
| 418 | .symbol = .{ |
| 419 | .n_strx = n_strx, |
| 420 | .n_type = std.macho.N_UNDF | std.macho.N_EXT, |
| 421 | .n_sect = 0, |
| 422 | .n_desc = std.macho.REFERENCE_FLAG_UNDEFINED_NON_LAZY | std.macho.N_SYMBOL_RESOLVER, |
| 423 | .n_value = 0, |
| 424 | }, |
| 425 | .dylib_ordinal = 1, |
| 426 | .index = index, |
| 427 | }); |
| 428 | } |
| 429 | |
| 430 | fn allocateTextSegment(self: *Zld) void { |
| 431 | const seg = &self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 432 | const nexterns = @intCast(u32, self.lazy_imports.items().len); |
| 433 | |
| 434 | // Set stubs and stub_helper sizes |
| 435 | const stubs = &seg.sections.items[self.stubs_section_index.?]; |
| 436 | const stub_helper = &seg.sections.items[self.stub_helper_section_index.?]; |
| 437 | stubs.size += nexterns * stubs.reserved2; |
| 438 | |
| 439 | const stub_size: u4 = switch (self.arch.?) { |
| 440 | .x86_64 => 10, |
| 441 | .aarch64 => 3 * @sizeOf(u32), |
| 442 | else => unreachable, |
| 443 | }; |
| 444 | stub_helper.size += nexterns * stub_size; |
| 445 | |
| 446 | var sizeofcmds: u64 = 0; |
| 447 | for (self.load_commands.items) |lc| { |
| 448 | sizeofcmds += lc.cmdsize(); |
| 449 | } |
| 450 | |
| 451 | self.allocateSegment(self.text_segment_cmd_index.?, 0, sizeofcmds, true); |
| 452 | } |
| 453 | |
| 454 | fn allocateDataSegment(self: *Zld) void { |
| 455 | const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 456 | const nonlazy = @intCast(u32, self.nonlazy_imports.items().len); |
| 457 | const lazy = @intCast(u32, self.lazy_imports.items().len); |
| 458 | |
| 459 | // Set got size |
| 460 | const got = &seg.sections.items[self.got_section_index.?]; |
| 461 | got.size += nonlazy * @sizeOf(u64); |
| 462 | |
| 463 | // Set la_symbol_ptr and data size |
| 464 | const la_symbol_ptr = &seg.sections.items[self.la_symbol_ptr_section_index.?]; |
| 465 | const data = &seg.sections.items[self.data_section_index.?]; |
| 466 | la_symbol_ptr.size += lazy * @sizeOf(u64); |
| 467 | data.size += @sizeOf(u64); // TODO when do we need more? |
| 468 | |
| 469 | const text_seg = self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 470 | const offset = text_seg.inner.fileoff + text_seg.inner.filesize; |
| 471 | self.allocateSegment(self.data_segment_cmd_index.?, offset, 0, false); |
| 472 | } |
| 473 | |
| 474 | fn allocateLinkeditSegment(self: *Zld) void { |
| 475 | const data_seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 476 | const offset = data_seg.inner.fileoff + data_seg.inner.filesize; |
| 477 | self.allocateSegment(self.linkedit_segment_cmd_index.?, offset, 0, false); |
| 478 | } |
| 479 | |
| 480 | fn allocateSegment(self: *Zld, index: u16, offset: u64, start: u64, reverse: bool) void { |
| 481 | const base_vmaddr = self.load_commands.items[self.pagezero_segment_cmd_index.?].Segment.inner.vmsize; |
| 482 | const seg = &self.load_commands.items[index].Segment; |
| 483 | |
| 484 | // Calculate segment size |
| 485 | var total_size = start; |
| 486 | for (seg.sections.items) |sect| { |
| 487 | total_size += sect.size; |
| 488 | } |
| 489 | const aligned_size = mem.alignForwardGeneric(u64, total_size, self.page_size.?); |
| 490 | seg.inner.vmaddr = base_vmaddr + offset; |
| 491 | seg.inner.vmsize = aligned_size; |
| 492 | seg.inner.fileoff = offset; |
| 493 | seg.inner.filesize = aligned_size; |
| 494 | |
| 495 | // Allocate section offsets |
| 496 | if (reverse) { |
| 497 | var end_off: u64 = seg.inner.fileoff + seg.inner.filesize; |
| 498 | var count: usize = seg.sections.items.len; |
| 499 | while (count > 0) : (count -= 1) { |
| 500 | const sec = &seg.sections.items[count - 1]; |
| 501 | end_off -= mem.alignForwardGeneric(u64, sec.size, @sizeOf(u32)); // TODO Should we always align to 4? |
| 502 | sec.offset = @intCast(u32, end_off); |
| 503 | sec.addr = base_vmaddr + end_off; |
| 504 | } |
| 505 | } else { |
| 506 | var next_off: u64 = seg.inner.fileoff; |
| 507 | for (seg.sections.items) |*sect| { |
| 508 | sect.offset = @intCast(u32, next_off); |
| 509 | sect.addr = base_vmaddr + next_off; |
| 510 | next_off += mem.alignForwardGeneric(u64, sect.size, @sizeOf(u32)); // TODO Should we always align to 4? |
| 511 | } |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | fn writeStubHelperCommon(self: *Zld) !void { |
| 516 | const text_segment = &self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 517 | const stub_helper = &text_segment.sections.items[self.stub_helper_section_index.?]; |
| 518 | const data_segment = &self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 519 | const data = &data_segment.sections.items[self.data_section_index.?]; |
| 520 | const la_symbol_ptr = data_segment.sections.items[self.la_symbol_ptr_section_index.?]; |
| 521 | const got = &data_segment.sections.items[self.got_section_index.?]; |
| 522 | |
| 523 | self.stub_helper_stubs_start_off = blk: { |
| 524 | switch (self.arch.?) { |
| 525 | .x86_64 => { |
| 526 | const code_size = 15; |
| 527 | var code: [code_size]u8 = undefined; |
| 528 | // lea %r11, [rip + disp] |
| 529 | code[0] = 0x4c; |
| 530 | code[1] = 0x8d; |
| 531 | code[2] = 0x1d; |
| 532 | { |
| 533 | const target_addr = data.addr + data.size - @sizeOf(u64); |
| 534 | const displacement = try math.cast(u32, target_addr - stub_helper.addr - 7); |
| 535 | mem.writeIntLittle(u32, code[3..7], displacement); |
| 536 | } |
| 537 | // push %r11 |
| 538 | code[7] = 0x41; |
| 539 | code[8] = 0x53; |
| 540 | // jmp [rip + disp] |
| 541 | code[9] = 0xff; |
| 542 | code[10] = 0x25; |
| 543 | { |
| 544 | const dyld_stub_binder = self.nonlazy_imports.get("dyld_stub_binder").?; |
| 545 | const addr = (got.addr + dyld_stub_binder.index * @sizeOf(u64)); |
| 546 | const displacement = try math.cast(u32, addr - stub_helper.addr - code_size); |
| 547 | mem.writeIntLittle(u32, code[11..], displacement); |
| 548 | } |
| 549 | try self.file.?.pwriteAll(&code, stub_helper.offset); |
| 550 | break :blk stub_helper.offset + code_size; |
| 551 | }, |
| 552 | .aarch64 => { |
| 553 | var code: [4 * @sizeOf(u32)]u8 = undefined; |
| 554 | { |
| 555 | const target_addr = data.addr + data.size - @sizeOf(u64); |
| 556 | const displacement = @bitCast(u21, try math.cast(i21, target_addr - stub_helper.addr)); |
| 557 | // adr x17, disp |
| 558 | mem.writeIntLittle(u32, code[0..4], Arm64.adr(17, displacement).toU32()); |
| 559 | } |
| 560 | // stp x16, x17, [sp, #-16]! |
| 561 | code[4] = 0xf0; |
| 562 | code[5] = 0x47; |
| 563 | code[6] = 0xbf; |
| 564 | code[7] = 0xa9; |
| 565 | { |
| 566 | const dyld_stub_binder = self.nonlazy_imports.get("dyld_stub_binder").?; |
| 567 | const addr = (got.addr + dyld_stub_binder.index * @sizeOf(u64)); |
| 568 | const displacement = try math.divExact(u64, addr - stub_helper.addr - 2 * @sizeOf(u32), 4); |
| 569 | const literal = try math.cast(u19, displacement); |
| 570 | // ldr x16, label |
| 571 | mem.writeIntLittle(u32, code[8..12], Arm64.ldr(16, literal, 1).toU32()); |
| 572 | } |
| 573 | // br x16 |
| 574 | code[12] = 0x00; |
| 575 | code[13] = 0x02; |
| 576 | code[14] = 0x1f; |
| 577 | code[15] = 0xd6; |
| 578 | try self.file.?.pwriteAll(&code, stub_helper.offset); |
| 579 | break :blk stub_helper.offset + 4 * @sizeOf(u32); |
| 580 | }, |
| 581 | else => unreachable, |
| 582 | } |
| 583 | }; |
| 584 | |
| 585 | for (self.lazy_imports.items()) |_, i| { |
| 586 | const index = @intCast(u32, i); |
| 587 | try self.writeLazySymbolPointer(index); |
| 588 | try self.writeStub(index); |
| 589 | try self.writeStubInStubHelper(index); |
| 590 | } |
| 591 | } |
| 592 | |
| 593 | fn writeLazySymbolPointer(self: *Zld, index: u32) !void { |
| 594 | const text_segment = self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 595 | const stub_helper = text_segment.sections.items[self.stub_helper_section_index.?]; |
| 596 | const data_segment = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 597 | const la_symbol_ptr = data_segment.sections.items[self.la_symbol_ptr_section_index.?]; |
| 598 | |
| 599 | const stub_size: u4 = switch (self.arch.?) { |
| 600 | .x86_64 => 10, |
| 601 | .aarch64 => 3 * @sizeOf(u32), |
| 602 | else => unreachable, |
| 603 | }; |
| 604 | const stub_off = self.stub_helper_stubs_start_off.? + index * stub_size; |
| 605 | const end = stub_helper.addr + stub_off - stub_helper.offset; |
| 606 | var buf: [@sizeOf(u64)]u8 = undefined; |
| 607 | mem.writeIntLittle(u64, &buf, end); |
| 608 | const off = la_symbol_ptr.offset + index * @sizeOf(u64); |
| 609 | log.debug("writing lazy symbol pointer entry 0x{x} at 0x{x}", .{ end, off }); |
| 610 | try self.file.?.pwriteAll(&buf, off); |
| 611 | } |
| 612 | |
| 613 | fn writeStub(self: *Zld, index: u32) !void { |
| 614 | const text_segment = self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 615 | const stubs = text_segment.sections.items[self.stubs_section_index.?]; |
| 616 | const data_segment = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 617 | const la_symbol_ptr = data_segment.sections.items[self.la_symbol_ptr_section_index.?]; |
| 618 | |
| 619 | const stub_off = stubs.offset + index * stubs.reserved2; |
| 620 | const stub_addr = stubs.addr + index * stubs.reserved2; |
| 621 | const la_ptr_addr = la_symbol_ptr.addr + index * @sizeOf(u64); |
| 622 | log.debug("writing stub at 0x{x}", .{stub_off}); |
| 623 | var code = try self.allocator.alloc(u8, stubs.reserved2); |
| 624 | defer self.allocator.free(code); |
| 625 | switch (self.arch.?) { |
| 626 | .x86_64 => { |
| 627 | assert(la_ptr_addr >= stub_addr + stubs.reserved2); |
| 628 | const displacement = try math.cast(u32, la_ptr_addr - stub_addr - stubs.reserved2); |
| 629 | // jmp |
| 630 | code[0] = 0xff; |
| 631 | code[1] = 0x25; |
| 632 | mem.writeIntLittle(u32, code[2..][0..4], displacement); |
| 633 | }, |
| 634 | .aarch64 => { |
| 635 | assert(la_ptr_addr >= stub_addr); |
| 636 | const displacement = try math.divExact(u64, la_ptr_addr - stub_addr, 4); |
| 637 | const literal = try math.cast(u19, displacement); |
| 638 | // ldr x16, literal |
| 639 | mem.writeIntLittle(u32, code[0..4], Arm64.ldr(16, literal, 1).toU32()); |
| 640 | // br x16 |
| 641 | mem.writeIntLittle(u32, code[4..8], Arm64.br(16).toU32()); |
| 642 | }, |
| 643 | else => unreachable, |
| 644 | } |
| 645 | try self.file.?.pwriteAll(code, stub_off); |
| 646 | } |
| 647 | |
| 648 | fn writeStubInStubHelper(self: *Zld, index: u32) !void { |
| 649 | const text_segment = self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 650 | const stub_helper = text_segment.sections.items[self.stub_helper_section_index.?]; |
| 651 | |
| 652 | const stub_size: u4 = switch (self.arch.?) { |
| 653 | .x86_64 => 10, |
| 654 | .aarch64 => 3 * @sizeOf(u32), |
| 655 | else => unreachable, |
| 656 | }; |
| 657 | const stub_off = self.stub_helper_stubs_start_off.? + index * stub_size; |
| 658 | var code = try self.allocator.alloc(u8, stub_size); |
| 659 | defer self.allocator.free(code); |
| 660 | switch (self.arch.?) { |
| 661 | .x86_64 => { |
| 662 | const displacement = try math.cast( |
| 663 | i32, |
| 664 | @intCast(i64, stub_helper.offset) - @intCast(i64, stub_off) - stub_size, |
| 665 | ); |
| 666 | // pushq |
| 667 | code[0] = 0x68; |
| 668 | mem.writeIntLittle(u32, code[1..][0..4], 0x0); // Just a placeholder populated in `populateLazyBindOffsetsInStubHelper`. |
| 669 | // jmpq |
| 670 | code[5] = 0xe9; |
| 671 | mem.writeIntLittle(u32, code[6..][0..4], @bitCast(u32, displacement)); |
| 672 | }, |
| 673 | .aarch64 => { |
| 674 | const displacement = try math.cast(i28, @intCast(i64, stub_helper.offset) - @intCast(i64, stub_off) - 4); |
| 675 | const literal = @divExact(stub_size - @sizeOf(u32), 4); |
| 676 | // ldr w16, literal |
| 677 | mem.writeIntLittle(u32, code[0..4], Arm64.ldr(16, literal, 0).toU32()); |
| 678 | // b disp |
| 679 | mem.writeIntLittle(u32, code[4..8], Arm64.b(displacement).toU32()); |
| 680 | mem.writeIntLittle(u32, code[8..12], 0x0); // Just a placeholder populated in `populateLazyBindOffsetsInStubHelper`. |
| 681 | }, |
| 682 | else => unreachable, |
| 683 | } |
| 684 | try self.file.?.pwriteAll(code, stub_off); |
| 685 | } |
| 686 | |
| 687 | fn resolveSymbols(self: *Zld) !void { |
| 688 | const Address = struct { |
| 689 | addr: u64, |
| 690 | size: u64, |
| 691 | }; |
| 692 | var next_address = std.AutoHashMap(DirectoryKey, Address).init(self.allocator); |
| 693 | defer next_address.deinit(); |
| 694 | |
| 695 | for (self.objects.items) |object| { |
| 696 | const seg = object.load_commands.items[object.segment_cmd_index.?].Segment; |
| 697 | |
| 698 | for (seg.sections.items) |sect| { |
| 699 | const key: DirectoryKey = .{ |
| 700 | .segname = sect.segname, |
| 701 | .sectname = sect.sectname, |
| 702 | }; |
| 703 | const indices = self.directory.get(key) orelse continue; |
| 704 | const out_seg = self.load_commands.items[indices.seg_index].Segment; |
| 705 | const out_sect = out_seg.sections.items[indices.sect_index]; |
| 706 | |
| 707 | const res = try next_address.getOrPut(key); |
| 708 | const next = &res.entry.value; |
| 709 | if (res.found_existing) { |
| 710 | next.addr += next.size; |
| 711 | } else { |
| 712 | next.addr = out_sect.addr; |
| 713 | } |
| 714 | next.size = sect.size; |
| 715 | } |
| 716 | |
| 717 | for (object.symtab.items) |sym| { |
| 718 | if (isImport(&sym)) continue; |
| 719 | |
| 720 | const sym_name = object.getString(sym.n_strx); |
| 721 | |
| 722 | if (isLocal(&sym) and self.locals.get(sym_name) != null) { |
| 723 | log.debug("symbol '{s}' already exists; skipping", .{sym_name}); |
| 724 | continue; |
| 725 | } |
| 726 | |
| 727 | const sect = seg.sections.items[sym.n_sect - 1]; |
| 728 | const key: DirectoryKey = .{ |
| 729 | .segname = sect.segname, |
| 730 | .sectname = sect.sectname, |
| 731 | }; |
| 732 | const res = self.directory.get(key) orelse continue; |
| 733 | |
| 734 | const n_strx = try self.makeString(sym_name); |
| 735 | const n_value = sym.n_value - sect.addr + next_address.get(key).?.addr; |
| 736 | |
| 737 | log.debug("resolving '{s}' as local symbol at 0x{x}", .{ sym_name, n_value }); |
| 738 | |
| 739 | var n_sect = res.sect_index + 1; |
| 740 | for (self.load_commands.items) |sseg, i| { |
| 741 | if (i == res.seg_index) { |
| 742 | break; |
| 743 | } |
| 744 | n_sect += @intCast(u16, sseg.Segment.sections.items.len); |
| 745 | } |
| 746 | |
| 747 | var out_name = try self.allocator.dupe(u8, sym_name); |
| 748 | try self.locals.putNoClobber(self.allocator, out_name, .{ |
| 749 | .n_strx = n_strx, |
| 750 | .n_value = n_value, |
| 751 | .n_type = macho.N_SECT, |
| 752 | .n_desc = sym.n_desc, |
| 753 | .n_sect = @intCast(u8, n_sect), |
| 754 | }); |
| 755 | } |
| 756 | } |
| 757 | } |
| 758 | |
| 759 | fn doRelocs(self: *Zld) !void { |
| 760 | const Space = struct { |
| 761 | address: u64, |
| 762 | offset: u64, |
| 763 | size: u64, |
| 764 | }; |
| 765 | var next_space = std.AutoHashMap(DirectoryKey, Space).init(self.allocator); |
| 766 | defer next_space.deinit(); |
| 767 | |
| 768 | for (self.objects.items) |object| { |
| 769 | log.debug("\n\n", .{}); |
| 770 | log.debug("relocating object {s}", .{object.name}); |
| 771 | |
| 772 | const seg = object.load_commands.items[object.segment_cmd_index.?].Segment; |
| 773 | |
| 774 | for (seg.sections.items) |sect| { |
| 775 | const key: DirectoryKey = .{ |
| 776 | .segname = sect.segname, |
| 777 | .sectname = sect.sectname, |
| 778 | }; |
| 779 | const indices = self.directory.get(key) orelse continue; |
| 780 | const out_seg = self.load_commands.items[indices.seg_index].Segment; |
| 781 | const out_sect = out_seg.sections.items[indices.sect_index]; |
| 782 | |
| 783 | const res = try next_space.getOrPut(key); |
| 784 | const next = &res.entry.value; |
| 785 | if (res.found_existing) { |
| 786 | next.offset += next.size; |
| 787 | next.address += next.size; |
| 788 | } else { |
| 789 | next.offset = out_sect.offset; |
| 790 | next.address = out_sect.addr; |
| 791 | } |
| 792 | next.size = sect.size; |
| 793 | } |
| 794 | |
| 795 | for (seg.sections.items) |sect| { |
| 796 | const segname = parseName(§.segname); |
| 797 | const sectname = parseName(§.sectname); |
| 798 | |
| 799 | const key: DirectoryKey = .{ |
| 800 | .segname = sect.segname, |
| 801 | .sectname = sect.sectname, |
| 802 | }; |
| 803 | const next = next_space.get(key) orelse continue; |
| 804 | |
| 805 | var code = try self.allocator.alloc(u8, sect.size); |
| 806 | defer self.allocator.free(code); |
| 807 | _ = try object.file.preadAll(code, sect.offset); |
| 808 | |
| 809 | // Parse relocs (if any) |
| 810 | var raw_relocs = try self.allocator.alloc(u8, @sizeOf(macho.relocation_info) * sect.nreloc); |
| 811 | defer self.allocator.free(raw_relocs); |
| 812 | _ = try object.file.preadAll(raw_relocs, sect.reloff); |
| 813 | const relocs = mem.bytesAsSlice(macho.relocation_info, raw_relocs); |
| 814 | |
| 815 | var addend: ?u64 = null; |
| 816 | var sub: ?i64 = null; |
| 817 | |
| 818 | for (relocs) |rel| { |
| 819 | const off = @intCast(u32, rel.r_address); |
| 820 | const this_addr = next.address + off; |
| 821 | |
| 822 | switch (self.arch.?) { |
| 823 | .aarch64 => { |
| 824 | const rel_type = @intToEnum(macho.reloc_type_arm64, rel.r_type); |
| 825 | log.debug("{s}", .{rel_type}); |
| 826 | log.debug(" | source address 0x{x}", .{this_addr}); |
| 827 | log.debug(" | offset 0x{x}", .{off}); |
| 828 | |
| 829 | if (rel_type == .ARM64_RELOC_ADDEND) { |
| 830 | addend = rel.r_symbolnum; |
| 831 | log.debug(" | calculated addend = 0x{x}", .{addend}); |
| 832 | // TODO followed by either PAGE21 or PAGEOFF12 only. |
| 833 | continue; |
| 834 | } |
| 835 | }, |
| 836 | .x86_64 => { |
| 837 | const rel_type = @intToEnum(macho.reloc_type_x86_64, rel.r_type); |
| 838 | log.debug("{s}", .{rel_type}); |
| 839 | log.debug(" | source address 0x{x}", .{this_addr}); |
| 840 | log.debug(" | offset 0x{x}", .{off}); |
| 841 | }, |
| 842 | else => {}, |
| 843 | } |
| 844 | |
| 845 | const target_addr = try self.relocTargetAddr(object, rel, next_space); |
| 846 | log.debug(" | target address 0x{x}", .{target_addr}); |
| 847 | if (rel.r_extern == 1) { |
| 848 | const target_symname = object.getString(object.symtab.items[rel.r_symbolnum].n_strx); |
| 849 | log.debug(" | target symbol '{s}'", .{target_symname}); |
| 850 | } else { |
| 851 | const target_sectname = seg.sections.items[rel.r_symbolnum - 1].sectname; |
| 852 | log.debug(" | target section '{s}'", .{parseName(&target_sectname)}); |
| 853 | } |
| 854 | |
| 855 | switch (self.arch.?) { |
| 856 | .x86_64 => { |
| 857 | const rel_type = @intToEnum(macho.reloc_type_x86_64, rel.r_type); |
| 858 | |
| 859 | switch (rel_type) { |
| 860 | .X86_64_RELOC_BRANCH, |
| 861 | .X86_64_RELOC_GOT_LOAD, |
| 862 | .X86_64_RELOC_GOT, |
| 863 | => { |
| 864 | assert(rel.r_length == 2); |
| 865 | const inst = code[off..][0..4]; |
| 866 | const displacement = @bitCast(u32, @intCast(i32, @intCast(i64, target_addr) - @intCast(i64, this_addr) - 4)); |
| 867 | mem.writeIntLittle(u32, inst, displacement); |
| 868 | }, |
| 869 | .X86_64_RELOC_TLV => { |
| 870 | assert(rel.r_length == 2); |
| 871 | // We need to rewrite the opcode from movq to leaq. |
| 872 | code[off - 2] = 0x8d; |
| 873 | // Add displacement. |
| 874 | const inst = code[off..][0..4]; |
| 875 | const displacement = @bitCast(u32, @intCast(i32, @intCast(i64, target_addr) - @intCast(i64, this_addr) - 4)); |
| 876 | mem.writeIntLittle(u32, inst, displacement); |
| 877 | }, |
| 878 | .X86_64_RELOC_SIGNED, |
| 879 | .X86_64_RELOC_SIGNED_1, |
| 880 | .X86_64_RELOC_SIGNED_2, |
| 881 | .X86_64_RELOC_SIGNED_4, |
| 882 | => { |
| 883 | assert(rel.r_length == 2); |
| 884 | const inst = code[off..][0..4]; |
| 885 | const offset: i32 = blk: { |
| 886 | if (rel.r_extern == 1) { |
| 887 | break :blk mem.readIntLittle(i32, inst); |
| 888 | } else { |
| 889 | // TODO it might be required here to parse the offset from the instruction placeholder, |
| 890 | // compare the displacement with the original displacement in the .o file, and adjust |
| 891 | // the displacement in the resultant binary file. |
| 892 | const correction: i4 = switch (rel_type) { |
| 893 | .X86_64_RELOC_SIGNED => 0, |
| 894 | .X86_64_RELOC_SIGNED_1 => 1, |
| 895 | .X86_64_RELOC_SIGNED_2 => 2, |
| 896 | .X86_64_RELOC_SIGNED_4 => 4, |
| 897 | else => unreachable, |
| 898 | }; |
| 899 | break :blk correction; |
| 900 | } |
| 901 | }; |
| 902 | log.debug(" | calculated addend 0x{x}", .{offset}); |
| 903 | const result = @intCast(i64, target_addr) - @intCast(i64, this_addr) - 4 + offset; |
| 904 | const displacement = @bitCast(u32, @intCast(i32, result)); |
| 905 | mem.writeIntLittle(u32, inst, displacement); |
| 906 | }, |
| 907 | .X86_64_RELOC_SUBTRACTOR => { |
| 908 | sub = @intCast(i64, target_addr); |
| 909 | }, |
| 910 | .X86_64_RELOC_UNSIGNED => { |
| 911 | switch (rel.r_length) { |
| 912 | 3 => { |
| 913 | const inst = code[off..][0..8]; |
| 914 | const offset = mem.readIntLittle(i64, inst); |
| 915 | log.debug(" | calculated addend 0x{x}", .{offset}); |
| 916 | const result = if (sub) |s| |
| 917 | @intCast(i64, target_addr) - s + offset |
| 918 | else |
| 919 | @intCast(i64, target_addr) + offset; |
| 920 | mem.writeIntLittle(u64, inst, @bitCast(u64, result)); |
| 921 | sub = null; |
| 922 | |
| 923 | // TODO should handle this better. |
| 924 | if (mem.eql(u8, segname, "__DATA")) outer: { |
| 925 | if (!mem.eql(u8, sectname, "__data") and |
| 926 | !mem.eql(u8, sectname, "__const") and |
| 927 | !mem.eql(u8, sectname, "__mod_init_func")) break :outer; |
| 928 | const this_seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 929 | const this_offset = next.address + off - this_seg.inner.vmaddr; |
| 930 | try self.local_rebases.append(self.allocator, .{ |
| 931 | .offset = this_offset, |
| 932 | .segment_id = @intCast(u16, self.data_segment_cmd_index.?), |
| 933 | }); |
| 934 | } |
| 935 | }, |
| 936 | 2 => { |
| 937 | const inst = code[off..][0..4]; |
| 938 | const offset = mem.readIntLittle(i32, inst); |
| 939 | log.debug(" | calculated addend 0x{x}", .{offset}); |
| 940 | const result = if (sub) |s| |
| 941 | @intCast(i64, target_addr) - s + offset |
| 942 | else |
| 943 | @intCast(i64, target_addr) + offset; |
| 944 | mem.writeIntLittle(u32, inst, @truncate(u32, @bitCast(u64, result))); |
| 945 | sub = null; |
| 946 | }, |
| 947 | else => |len| { |
| 948 | log.err("unexpected relocation length 0x{x}", .{len}); |
| 949 | return error.UnexpectedRelocationLength; |
| 950 | }, |
| 951 | } |
| 952 | }, |
| 953 | } |
| 954 | }, |
| 955 | .aarch64 => { |
| 956 | const rel_type = @intToEnum(macho.reloc_type_arm64, rel.r_type); |
| 957 | |
| 958 | switch (rel_type) { |
| 959 | .ARM64_RELOC_BRANCH26 => { |
| 960 | assert(rel.r_length == 2); |
| 961 | const inst = code[off..][0..4]; |
| 962 | const displacement = @intCast(i28, @intCast(i64, target_addr) - @intCast(i64, this_addr)); |
| 963 | var parsed = mem.bytesAsValue(meta.TagPayload(Arm64, Arm64.Branch), inst); |
| 964 | parsed.disp = @truncate(u26, @bitCast(u28, displacement) >> 2); |
| 965 | }, |
| 966 | .ARM64_RELOC_PAGE21, |
| 967 | .ARM64_RELOC_GOT_LOAD_PAGE21, |
| 968 | .ARM64_RELOC_TLVP_LOAD_PAGE21, |
| 969 | => { |
| 970 | assert(rel.r_length == 2); |
| 971 | const inst = code[off..][0..4]; |
| 972 | const ta = if (addend) |a| target_addr + a else target_addr; |
| 973 | const this_page = @intCast(i32, this_addr >> 12); |
| 974 | const target_page = @intCast(i32, ta >> 12); |
| 975 | const pages = @bitCast(u21, @intCast(i21, target_page - this_page)); |
| 976 | log.debug(" | moving by {} pages", .{pages}); |
| 977 | var parsed = mem.bytesAsValue(meta.TagPayload(Arm64, Arm64.Address), inst); |
| 978 | parsed.immhi = @truncate(u19, pages >> 2); |
| 979 | parsed.immlo = @truncate(u2, pages); |
| 980 | addend = null; |
| 981 | }, |
| 982 | .ARM64_RELOC_PAGEOFF12, |
| 983 | .ARM64_RELOC_GOT_LOAD_PAGEOFF12, |
| 984 | => { |
| 985 | const inst = code[off..][0..4]; |
| 986 | if (Arm64.isArithmetic(inst)) { |
| 987 | log.debug(" | detected ADD opcode", .{}); |
| 988 | // add |
| 989 | var parsed = mem.bytesAsValue(meta.TagPayload(Arm64, Arm64.Add), inst); |
| 990 | const ta = if (addend) |a| target_addr + a else target_addr; |
| 991 | const narrowed = @truncate(u12, ta); |
| 992 | parsed.offset = narrowed; |
| 993 | } else { |
| 994 | log.debug(" | detected LDR/STR opcode", .{}); |
| 995 | // ldr/str |
| 996 | var parsed = mem.bytesAsValue(meta.TagPayload(Arm64, Arm64.LoadRegister), inst); |
| 997 | const ta = if (addend) |a| target_addr + a else target_addr; |
| 998 | const narrowed = @truncate(u12, ta); |
| 999 | const offset = if (parsed.size == 1) @divExact(narrowed, 8) else @divExact(narrowed, 4); |
| 1000 | parsed.offset = @truncate(u12, offset); |
| 1001 | } |
| 1002 | addend = null; |
| 1003 | }, |
| 1004 | .ARM64_RELOC_TLVP_LOAD_PAGEOFF12 => { |
| 1005 | // TODO why is this necessary? |
| 1006 | const RegInfo = struct { |
| 1007 | rt: u5, |
| 1008 | rn: u5, |
| 1009 | size: u1, |
| 1010 | }; |
| 1011 | const inst = code[off..][0..4]; |
| 1012 | const parsed: RegInfo = blk: { |
| 1013 | if (Arm64.isArithmetic(inst)) { |
| 1014 | const curr = mem.bytesAsValue(meta.TagPayload(Arm64, Arm64.Add), inst); |
| 1015 | break :blk .{ .rt = curr.rt, .rn = curr.rn, .size = curr.size }; |
| 1016 | } else { |
| 1017 | const curr = mem.bytesAsValue(meta.TagPayload(Arm64, Arm64.LoadRegister), inst); |
| 1018 | break :blk .{ .rt = curr.rt, .rn = curr.rn, .size = curr.size }; |
| 1019 | } |
| 1020 | }; |
| 1021 | const ta = if (addend) |a| target_addr + a else target_addr; |
| 1022 | const narrowed = @truncate(u12, ta); |
| 1023 | log.debug(" | rewriting TLV access to ADD opcode", .{}); |
| 1024 | // For TLV, we always generate an add instruction. |
| 1025 | mem.writeIntLittle(u32, inst, Arm64.add(parsed.rt, parsed.rn, narrowed, parsed.size).toU32()); |
| 1026 | }, |
| 1027 | .ARM64_RELOC_SUBTRACTOR => { |
| 1028 | sub = @intCast(i64, target_addr); |
| 1029 | }, |
| 1030 | .ARM64_RELOC_UNSIGNED => { |
| 1031 | switch (rel.r_length) { |
| 1032 | 3 => { |
| 1033 | const inst = code[off..][0..8]; |
| 1034 | const offset = mem.readIntLittle(i64, inst); |
| 1035 | log.debug(" | calculated addend 0x{x}", .{offset}); |
| 1036 | const result = if (sub) |s| |
| 1037 | @intCast(i64, target_addr) - s + offset |
| 1038 | else |
| 1039 | @intCast(i64, target_addr) + offset; |
| 1040 | mem.writeIntLittle(u64, inst, @bitCast(u64, result)); |
| 1041 | sub = null; |
| 1042 | |
| 1043 | // TODO should handle this better. |
| 1044 | if (mem.eql(u8, segname, "__DATA")) outer: { |
| 1045 | if (!mem.eql(u8, sectname, "__data") and |
| 1046 | !mem.eql(u8, sectname, "__const") and |
| 1047 | !mem.eql(u8, sectname, "__mod_init_func")) break :outer; |
| 1048 | const this_seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1049 | const this_offset = next.address + off - this_seg.inner.vmaddr; |
| 1050 | try self.local_rebases.append(self.allocator, .{ |
| 1051 | .offset = this_offset, |
| 1052 | .segment_id = @intCast(u16, self.data_segment_cmd_index.?), |
| 1053 | }); |
| 1054 | } |
| 1055 | }, |
| 1056 | 2 => { |
| 1057 | const inst = code[off..][0..4]; |
| 1058 | const offset = mem.readIntLittle(i32, inst); |
| 1059 | log.debug(" | calculated addend 0x{x}", .{offset}); |
| 1060 | const result = if (sub) |s| |
| 1061 | @intCast(i64, target_addr) - s + offset |
| 1062 | else |
| 1063 | @intCast(i64, target_addr) + offset; |
| 1064 | mem.writeIntLittle(u32, inst, @truncate(u32, @bitCast(u64, result))); |
| 1065 | sub = null; |
| 1066 | }, |
| 1067 | else => |len| { |
| 1068 | log.err("unexpected relocation length 0x{x}", .{len}); |
| 1069 | return error.UnexpectedRelocationLength; |
| 1070 | }, |
| 1071 | } |
| 1072 | }, |
| 1073 | .ARM64_RELOC_POINTER_TO_GOT => return error.TODOArm64RelocPointerToGot, |
| 1074 | else => unreachable, |
| 1075 | } |
| 1076 | }, |
| 1077 | else => unreachable, |
| 1078 | } |
| 1079 | } |
| 1080 | |
| 1081 | log.debug("writing contents of '{s},{s}' section from '{s}' from 0x{x} to 0x{x}", .{ |
| 1082 | segname, |
| 1083 | sectname, |
| 1084 | object.name, |
| 1085 | next.offset, |
| 1086 | next.offset + next.size, |
| 1087 | }); |
| 1088 | |
| 1089 | if (mem.eql(u8, sectname, "__bss") or |
| 1090 | mem.eql(u8, sectname, "__thread_bss") or |
| 1091 | mem.eql(u8, sectname, "__thread_vars")) |
| 1092 | { |
| 1093 | // Zero-out the space |
| 1094 | var zeroes = try self.allocator.alloc(u8, next.size); |
| 1095 | defer self.allocator.free(zeroes); |
| 1096 | mem.set(u8, zeroes, 0); |
| 1097 | try self.file.?.pwriteAll(zeroes, next.offset); |
| 1098 | } else { |
| 1099 | try self.file.?.pwriteAll(code, next.offset); |
| 1100 | } |
| 1101 | } |
| 1102 | } |
| 1103 | } |
| 1104 | |
| 1105 | fn relocTargetAddr(self: *Zld, object: Object, rel: macho.relocation_info, next_space: anytype) !u64 { |
| 1106 | const seg = object.load_commands.items[object.segment_cmd_index.?].Segment; |
| 1107 | const target_addr = blk: { |
| 1108 | if (rel.r_extern == 1) { |
| 1109 | const sym = object.symtab.items[rel.r_symbolnum]; |
| 1110 | if (isLocal(&sym) or isExport(&sym)) { |
| 1111 | // Relocate using section offsets only. |
| 1112 | const source_sect = seg.sections.items[sym.n_sect - 1]; |
| 1113 | const target_space = next_space.get(.{ |
| 1114 | .segname = source_sect.segname, |
| 1115 | .sectname = source_sect.sectname, |
| 1116 | }).?; |
| 1117 | break :blk target_space.address + sym.n_value - source_sect.addr; |
| 1118 | } else if (isImport(&sym)) { |
| 1119 | // Relocate to either the artifact's local symbol, or an import from |
| 1120 | // shared library. |
| 1121 | const sym_name = object.getString(sym.n_strx); |
| 1122 | if (self.locals.get(sym_name)) |loc| { |
| 1123 | break :blk loc.n_value; |
| 1124 | } else if (self.lazy_imports.get(sym_name)) |ext| { |
| 1125 | const segment = self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 1126 | const stubs = segment.sections.items[self.stubs_section_index.?]; |
| 1127 | break :blk stubs.addr + ext.index * stubs.reserved2; |
| 1128 | } else if (self.nonlazy_imports.get(sym_name)) |ext| { |
| 1129 | const segment = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1130 | const got = segment.sections.items[self.got_section_index.?]; |
| 1131 | break :blk got.addr + ext.index * @sizeOf(u64); |
| 1132 | } else if (self.threadlocal_imports.get(sym_name)) |ext| { |
| 1133 | const segment = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1134 | const tlv = segment.sections.items[self.tlv_section_index.?]; |
| 1135 | break :blk tlv.addr + ext.index * @sizeOf(u64); |
| 1136 | } else { |
| 1137 | log.err("failed to resolve symbol '{s}' as a relocation target", .{sym_name}); |
| 1138 | return error.FailedToResolveRelocationTarget; |
| 1139 | } |
| 1140 | } else { |
| 1141 | log.err("unexpected symbol {}, {s}", .{ sym, object.getString(sym.n_strx) }); |
| 1142 | return error.UnexpectedSymbolWhenRelocating; |
| 1143 | } |
| 1144 | } else { |
| 1145 | // TODO I think we need to reparse the relocation_info as scattered_relocation_info |
| 1146 | // here to get the actual section plus offset into that section of the relocated |
| 1147 | // symbol. Unless the fine-grained location is encoded within the cell in the code |
| 1148 | // buffer? |
| 1149 | const source_sectname = seg.sections.items[rel.r_symbolnum - 1]; |
| 1150 | const target_space = next_space.get(.{ |
| 1151 | .segname = source_sectname.segname, |
| 1152 | .sectname = source_sectname.sectname, |
| 1153 | }).?; |
| 1154 | break :blk target_space.address; |
| 1155 | } |
| 1156 | }; |
| 1157 | return target_addr; |
| 1158 | } |
| 1159 | |
| 1160 | fn populateMetadata(self: *Zld) !void { |
| 1161 | if (self.pagezero_segment_cmd_index == null) { |
| 1162 | self.pagezero_segment_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1163 | try self.load_commands.append(self.allocator, .{ |
| 1164 | .Segment = SegmentCommand.empty(.{ |
| 1165 | .cmd = macho.LC_SEGMENT_64, |
| 1166 | .cmdsize = @sizeOf(macho.segment_command_64), |
| 1167 | .segname = makeStaticString("__PAGEZERO"), |
| 1168 | .vmaddr = 0, |
| 1169 | .vmsize = 0x100000000, // size always set to 4GB |
| 1170 | .fileoff = 0, |
| 1171 | .filesize = 0, |
| 1172 | .maxprot = 0, |
| 1173 | .initprot = 0, |
| 1174 | .nsects = 0, |
| 1175 | .flags = 0, |
| 1176 | }), |
| 1177 | }); |
| 1178 | try self.addSegmentToDir(0); |
| 1179 | } |
| 1180 | |
| 1181 | if (self.text_segment_cmd_index == null) { |
| 1182 | self.text_segment_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1183 | try self.load_commands.append(self.allocator, .{ |
| 1184 | .Segment = SegmentCommand.empty(.{ |
| 1185 | .cmd = macho.LC_SEGMENT_64, |
| 1186 | .cmdsize = @sizeOf(macho.segment_command_64), |
| 1187 | .segname = makeStaticString("__TEXT"), |
| 1188 | .vmaddr = 0x100000000, // always starts at 4GB |
| 1189 | .vmsize = 0, |
| 1190 | .fileoff = 0, |
| 1191 | .filesize = 0, |
| 1192 | .maxprot = macho.VM_PROT_READ | macho.VM_PROT_EXECUTE, |
| 1193 | .initprot = macho.VM_PROT_READ | macho.VM_PROT_EXECUTE, |
| 1194 | .nsects = 0, |
| 1195 | .flags = 0, |
| 1196 | }), |
| 1197 | }); |
| 1198 | try self.addSegmentToDir(self.text_segment_cmd_index.?); |
| 1199 | } |
| 1200 | |
| 1201 | if (self.text_section_index == null) { |
| 1202 | const text_seg = &self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 1203 | self.text_section_index = @intCast(u16, text_seg.sections.items.len); |
| 1204 | const alignment: u2 = switch (self.arch.?) { |
| 1205 | .x86_64 => 0, |
| 1206 | .aarch64 => 2, |
| 1207 | else => unreachable, // unhandled architecture type |
| 1208 | }; |
| 1209 | try text_seg.append(self.allocator, .{ |
| 1210 | .sectname = makeStaticString("__text"), |
| 1211 | .segname = makeStaticString("__TEXT"), |
| 1212 | .addr = 0, |
| 1213 | .size = 0, |
| 1214 | .offset = 0, |
| 1215 | .@"align" = alignment, |
| 1216 | .reloff = 0, |
| 1217 | .nreloc = 0, |
| 1218 | .flags = macho.S_REGULAR | macho.S_ATTR_PURE_INSTRUCTIONS | macho.S_ATTR_SOME_INSTRUCTIONS, |
| 1219 | .reserved1 = 0, |
| 1220 | .reserved2 = 0, |
| 1221 | .reserved3 = 0, |
| 1222 | }); |
| 1223 | try self.addSectionToDir(.{ |
| 1224 | .seg_index = self.text_segment_cmd_index.?, |
| 1225 | .sect_index = self.text_section_index.?, |
| 1226 | }); |
| 1227 | } |
| 1228 | |
| 1229 | if (self.stubs_section_index == null) { |
| 1230 | const text_seg = &self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 1231 | self.stubs_section_index = @intCast(u16, text_seg.sections.items.len); |
| 1232 | const alignment: u2 = switch (self.arch.?) { |
| 1233 | .x86_64 => 0, |
| 1234 | .aarch64 => 2, |
| 1235 | else => unreachable, // unhandled architecture type |
| 1236 | }; |
| 1237 | const stub_size: u4 = switch (self.arch.?) { |
| 1238 | .x86_64 => 6, |
| 1239 | .aarch64 => 2 * @sizeOf(u32), |
| 1240 | else => unreachable, // unhandled architecture type |
| 1241 | }; |
| 1242 | try text_seg.append(self.allocator, .{ |
| 1243 | .sectname = makeStaticString("__stubs"), |
| 1244 | .segname = makeStaticString("__TEXT"), |
| 1245 | .addr = 0, |
| 1246 | .size = 0, |
| 1247 | .offset = 0, |
| 1248 | .@"align" = alignment, |
| 1249 | .reloff = 0, |
| 1250 | .nreloc = 0, |
| 1251 | .flags = macho.S_SYMBOL_STUBS | macho.S_ATTR_PURE_INSTRUCTIONS | macho.S_ATTR_SOME_INSTRUCTIONS, |
| 1252 | .reserved1 = 0, |
| 1253 | .reserved2 = stub_size, |
| 1254 | .reserved3 = 0, |
| 1255 | }); |
| 1256 | try self.addSectionToDir(.{ |
| 1257 | .seg_index = self.text_segment_cmd_index.?, |
| 1258 | .sect_index = self.stubs_section_index.?, |
| 1259 | }); |
| 1260 | } |
| 1261 | |
| 1262 | if (self.stub_helper_section_index == null) { |
| 1263 | const text_seg = &self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 1264 | self.stub_helper_section_index = @intCast(u16, text_seg.sections.items.len); |
| 1265 | const alignment: u2 = switch (self.arch.?) { |
| 1266 | .x86_64 => 0, |
| 1267 | .aarch64 => 2, |
| 1268 | else => unreachable, // unhandled architecture type |
| 1269 | }; |
| 1270 | const stub_helper_size: u5 = switch (self.arch.?) { |
| 1271 | .x86_64 => 15, |
| 1272 | .aarch64 => 6 * @sizeOf(u32), |
| 1273 | else => unreachable, |
| 1274 | }; |
| 1275 | try text_seg.append(self.allocator, .{ |
| 1276 | .sectname = makeStaticString("__stub_helper"), |
| 1277 | .segname = makeStaticString("__TEXT"), |
| 1278 | .addr = 0, |
| 1279 | .size = stub_helper_size, |
| 1280 | .offset = 0, |
| 1281 | .@"align" = alignment, |
| 1282 | .reloff = 0, |
| 1283 | .nreloc = 0, |
| 1284 | .flags = macho.S_REGULAR | macho.S_ATTR_PURE_INSTRUCTIONS | macho.S_ATTR_SOME_INSTRUCTIONS, |
| 1285 | .reserved1 = 0, |
| 1286 | .reserved2 = 0, |
| 1287 | .reserved3 = 0, |
| 1288 | }); |
| 1289 | try self.addSectionToDir(.{ |
| 1290 | .seg_index = self.text_segment_cmd_index.?, |
| 1291 | .sect_index = self.stub_helper_section_index.?, |
| 1292 | }); |
| 1293 | } |
| 1294 | |
| 1295 | if (self.data_segment_cmd_index == null) { |
| 1296 | self.data_segment_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1297 | try self.load_commands.append(self.allocator, .{ |
| 1298 | .Segment = SegmentCommand.empty(.{ |
| 1299 | .cmd = macho.LC_SEGMENT_64, |
| 1300 | .cmdsize = @sizeOf(macho.segment_command_64), |
| 1301 | .segname = makeStaticString("__DATA"), |
| 1302 | .vmaddr = 0, |
| 1303 | .vmsize = 0, |
| 1304 | .fileoff = 0, |
| 1305 | .filesize = 0, |
| 1306 | .maxprot = macho.VM_PROT_READ | macho.VM_PROT_WRITE, |
| 1307 | .initprot = macho.VM_PROT_READ | macho.VM_PROT_WRITE, |
| 1308 | .nsects = 0, |
| 1309 | .flags = 0, |
| 1310 | }), |
| 1311 | }); |
| 1312 | try self.addSegmentToDir(self.data_segment_cmd_index.?); |
| 1313 | } |
| 1314 | |
| 1315 | if (self.got_section_index == null) { |
| 1316 | const data_seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1317 | self.got_section_index = @intCast(u16, data_seg.sections.items.len); |
| 1318 | try data_seg.append(self.allocator, .{ |
| 1319 | .sectname = makeStaticString("__got"), |
| 1320 | .segname = makeStaticString("__DATA"), |
| 1321 | .addr = 0, |
| 1322 | .size = 0, |
| 1323 | .offset = 0, |
| 1324 | .@"align" = 3, // 2^3 = @sizeOf(u64) |
| 1325 | .reloff = 0, |
| 1326 | .nreloc = 0, |
| 1327 | .flags = macho.S_NON_LAZY_SYMBOL_POINTERS, |
| 1328 | .reserved1 = 0, |
| 1329 | .reserved2 = 0, |
| 1330 | .reserved3 = 0, |
| 1331 | }); |
| 1332 | try self.addSectionToDir(.{ |
| 1333 | .seg_index = self.data_segment_cmd_index.?, |
| 1334 | .sect_index = self.got_section_index.?, |
| 1335 | }); |
| 1336 | } |
| 1337 | |
| 1338 | if (self.la_symbol_ptr_section_index == null) { |
| 1339 | const data_seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1340 | self.la_symbol_ptr_section_index = @intCast(u16, data_seg.sections.items.len); |
| 1341 | try data_seg.append(self.allocator, .{ |
| 1342 | .sectname = makeStaticString("__la_symbol_ptr"), |
| 1343 | .segname = makeStaticString("__DATA"), |
| 1344 | .addr = 0, |
| 1345 | .size = 0, |
| 1346 | .offset = 0, |
| 1347 | .@"align" = 3, // 2^3 = @sizeOf(u64) |
| 1348 | .reloff = 0, |
| 1349 | .nreloc = 0, |
| 1350 | .flags = macho.S_LAZY_SYMBOL_POINTERS, |
| 1351 | .reserved1 = 0, |
| 1352 | .reserved2 = 0, |
| 1353 | .reserved3 = 0, |
| 1354 | }); |
| 1355 | try self.addSectionToDir(.{ |
| 1356 | .seg_index = self.data_segment_cmd_index.?, |
| 1357 | .sect_index = self.la_symbol_ptr_section_index.?, |
| 1358 | }); |
| 1359 | } |
| 1360 | |
| 1361 | if (self.data_section_index == null) { |
| 1362 | const data_seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1363 | self.data_section_index = @intCast(u16, data_seg.sections.items.len); |
| 1364 | try data_seg.append(self.allocator, .{ |
| 1365 | .sectname = makeStaticString("__data"), |
| 1366 | .segname = makeStaticString("__DATA"), |
| 1367 | .addr = 0, |
| 1368 | .size = 0, |
| 1369 | .offset = 0, |
| 1370 | .@"align" = 3, // 2^3 = @sizeOf(u64) |
| 1371 | .reloff = 0, |
| 1372 | .nreloc = 0, |
| 1373 | .flags = macho.S_REGULAR, |
| 1374 | .reserved1 = 0, |
| 1375 | .reserved2 = 0, |
| 1376 | .reserved3 = 0, |
| 1377 | }); |
| 1378 | try self.addSectionToDir(.{ |
| 1379 | .seg_index = self.data_segment_cmd_index.?, |
| 1380 | .sect_index = self.data_section_index.?, |
| 1381 | }); |
| 1382 | } |
| 1383 | |
| 1384 | if (self.linkedit_segment_cmd_index == null) { |
| 1385 | self.linkedit_segment_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1386 | try self.load_commands.append(self.allocator, .{ |
| 1387 | .Segment = SegmentCommand.empty(.{ |
| 1388 | .cmd = macho.LC_SEGMENT_64, |
| 1389 | .cmdsize = @sizeOf(macho.segment_command_64), |
| 1390 | .segname = makeStaticString("__LINKEDIT"), |
| 1391 | .vmaddr = 0, |
| 1392 | .vmsize = 0, |
| 1393 | .fileoff = 0, |
| 1394 | .filesize = 0, |
| 1395 | .maxprot = macho.VM_PROT_READ, |
| 1396 | .initprot = macho.VM_PROT_READ, |
| 1397 | .nsects = 0, |
| 1398 | .flags = 0, |
| 1399 | }), |
| 1400 | }); |
| 1401 | try self.addSegmentToDir(self.linkedit_segment_cmd_index.?); |
| 1402 | } |
| 1403 | |
| 1404 | if (self.dyld_info_cmd_index == null) { |
| 1405 | self.dyld_info_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1406 | try self.load_commands.append(self.allocator, .{ |
| 1407 | .DyldInfoOnly = .{ |
| 1408 | .cmd = macho.LC_DYLD_INFO_ONLY, |
| 1409 | .cmdsize = @sizeOf(macho.dyld_info_command), |
| 1410 | .rebase_off = 0, |
| 1411 | .rebase_size = 0, |
| 1412 | .bind_off = 0, |
| 1413 | .bind_size = 0, |
| 1414 | .weak_bind_off = 0, |
| 1415 | .weak_bind_size = 0, |
| 1416 | .lazy_bind_off = 0, |
| 1417 | .lazy_bind_size = 0, |
| 1418 | .export_off = 0, |
| 1419 | .export_size = 0, |
| 1420 | }, |
| 1421 | }); |
| 1422 | } |
| 1423 | |
| 1424 | if (self.symtab_cmd_index == null) { |
| 1425 | self.symtab_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1426 | try self.load_commands.append(self.allocator, .{ |
| 1427 | .Symtab = .{ |
| 1428 | .cmd = macho.LC_SYMTAB, |
| 1429 | .cmdsize = @sizeOf(macho.symtab_command), |
| 1430 | .symoff = 0, |
| 1431 | .nsyms = 0, |
| 1432 | .stroff = 0, |
| 1433 | .strsize = 0, |
| 1434 | }, |
| 1435 | }); |
| 1436 | try self.strtab.append(self.allocator, 0); |
| 1437 | } |
| 1438 | |
| 1439 | if (self.dysymtab_cmd_index == null) { |
| 1440 | self.dysymtab_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1441 | try self.load_commands.append(self.allocator, .{ |
| 1442 | .Dysymtab = .{ |
| 1443 | .cmd = macho.LC_DYSYMTAB, |
| 1444 | .cmdsize = @sizeOf(macho.dysymtab_command), |
| 1445 | .ilocalsym = 0, |
| 1446 | .nlocalsym = 0, |
| 1447 | .iextdefsym = 0, |
| 1448 | .nextdefsym = 0, |
| 1449 | .iundefsym = 0, |
| 1450 | .nundefsym = 0, |
| 1451 | .tocoff = 0, |
| 1452 | .ntoc = 0, |
| 1453 | .modtaboff = 0, |
| 1454 | .nmodtab = 0, |
| 1455 | .extrefsymoff = 0, |
| 1456 | .nextrefsyms = 0, |
| 1457 | .indirectsymoff = 0, |
| 1458 | .nindirectsyms = 0, |
| 1459 | .extreloff = 0, |
| 1460 | .nextrel = 0, |
| 1461 | .locreloff = 0, |
| 1462 | .nlocrel = 0, |
| 1463 | }, |
| 1464 | }); |
| 1465 | } |
| 1466 | |
| 1467 | if (self.dylinker_cmd_index == null) { |
| 1468 | self.dylinker_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1469 | const cmdsize = @intCast(u32, mem.alignForwardGeneric( |
| 1470 | u64, |
| 1471 | @sizeOf(macho.dylinker_command) + mem.lenZ(DEFAULT_DYLD_PATH), |
| 1472 | @sizeOf(u64), |
| 1473 | )); |
| 1474 | var dylinker_cmd = emptyGenericCommandWithData(macho.dylinker_command{ |
| 1475 | .cmd = macho.LC_LOAD_DYLINKER, |
| 1476 | .cmdsize = cmdsize, |
| 1477 | .name = @sizeOf(macho.dylinker_command), |
| 1478 | }); |
| 1479 | dylinker_cmd.data = try self.allocator.alloc(u8, cmdsize - dylinker_cmd.inner.name); |
| 1480 | mem.set(u8, dylinker_cmd.data, 0); |
| 1481 | mem.copy(u8, dylinker_cmd.data, mem.spanZ(DEFAULT_DYLD_PATH)); |
| 1482 | try self.load_commands.append(self.allocator, .{ .Dylinker = dylinker_cmd }); |
| 1483 | } |
| 1484 | |
| 1485 | if (self.libsystem_cmd_index == null) { |
| 1486 | self.libsystem_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1487 | const cmdsize = @intCast(u32, mem.alignForwardGeneric( |
| 1488 | u64, |
| 1489 | @sizeOf(macho.dylib_command) + mem.lenZ(LIB_SYSTEM_PATH), |
| 1490 | @sizeOf(u64), |
| 1491 | )); |
| 1492 | // TODO Find a way to work out runtime version from the OS version triple stored in std.Target. |
| 1493 | // In the meantime, we're gonna hardcode to the minimum compatibility version of 0.0.0. |
| 1494 | const min_version = 0x0; |
| 1495 | var dylib_cmd = emptyGenericCommandWithData(macho.dylib_command{ |
| 1496 | .cmd = macho.LC_LOAD_DYLIB, |
| 1497 | .cmdsize = cmdsize, |
| 1498 | .dylib = .{ |
| 1499 | .name = @sizeOf(macho.dylib_command), |
| 1500 | .timestamp = 2, // not sure why not simply 0; this is reverse engineered from Mach-O files |
| 1501 | .current_version = min_version, |
| 1502 | .compatibility_version = min_version, |
| 1503 | }, |
| 1504 | }); |
| 1505 | dylib_cmd.data = try self.allocator.alloc(u8, cmdsize - dylib_cmd.inner.dylib.name); |
| 1506 | mem.set(u8, dylib_cmd.data, 0); |
| 1507 | mem.copy(u8, dylib_cmd.data, mem.spanZ(LIB_SYSTEM_PATH)); |
| 1508 | try self.load_commands.append(self.allocator, .{ .Dylib = dylib_cmd }); |
| 1509 | } |
| 1510 | |
| 1511 | if (self.main_cmd_index == null) { |
| 1512 | self.main_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1513 | try self.load_commands.append(self.allocator, .{ |
| 1514 | .Main = .{ |
| 1515 | .cmd = macho.LC_MAIN, |
| 1516 | .cmdsize = @sizeOf(macho.entry_point_command), |
| 1517 | .entryoff = 0x0, |
| 1518 | .stacksize = 0, |
| 1519 | }, |
| 1520 | }); |
| 1521 | } |
| 1522 | |
| 1523 | if (self.source_version_cmd_index == null) { |
| 1524 | self.source_version_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1525 | try self.load_commands.append(self.allocator, .{ |
| 1526 | .SourceVersion = .{ |
| 1527 | .cmd = macho.LC_SOURCE_VERSION, |
| 1528 | .cmdsize = @sizeOf(macho.source_version_command), |
| 1529 | .version = 0x0, |
| 1530 | }, |
| 1531 | }); |
| 1532 | } |
| 1533 | |
| 1534 | if (self.uuid_cmd_index == null) { |
| 1535 | self.uuid_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1536 | var uuid_cmd: macho.uuid_command = .{ |
| 1537 | .cmd = macho.LC_UUID, |
| 1538 | .cmdsize = @sizeOf(macho.uuid_command), |
| 1539 | .uuid = undefined, |
| 1540 | }; |
| 1541 | std.crypto.random.bytes(&uuid_cmd.uuid); |
| 1542 | try self.load_commands.append(self.allocator, .{ .Uuid = uuid_cmd }); |
| 1543 | } |
| 1544 | |
| 1545 | if (self.code_signature_cmd_index == null and self.arch.? == .aarch64) { |
| 1546 | self.code_signature_cmd_index = @intCast(u16, self.load_commands.items.len); |
| 1547 | try self.load_commands.append(self.allocator, .{ |
| 1548 | .LinkeditData = .{ |
| 1549 | .cmd = macho.LC_CODE_SIGNATURE, |
| 1550 | .cmdsize = @sizeOf(macho.linkedit_data_command), |
| 1551 | .dataoff = 0, |
| 1552 | .datasize = 0, |
| 1553 | }, |
| 1554 | }); |
| 1555 | } |
| 1556 | } |
| 1557 | |
| 1558 | fn flush(self: *Zld) !void { |
| 1559 | { |
| 1560 | const seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1561 | for (seg.sections.items) |*sect| { |
| 1562 | const sectname = parseName(§.sectname); |
| 1563 | if (mem.eql(u8, sectname, "__bss") or mem.eql(u8, sectname, "__thread_bss")) { |
| 1564 | sect.offset = 0; |
| 1565 | } |
| 1566 | } |
| 1567 | } |
| 1568 | { |
| 1569 | const seg = &self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 1570 | for (seg.sections.items) |*sect| { |
| 1571 | if (mem.eql(u8, parseName(§.sectname), "__eh_frame")) { |
| 1572 | sect.flags = 0; |
| 1573 | } |
| 1574 | } |
| 1575 | } |
| 1576 | try self.setEntryPoint(); |
| 1577 | try self.writeRebaseInfoTable(); |
| 1578 | try self.writeBindInfoTable(); |
| 1579 | try self.writeLazyBindInfoTable(); |
| 1580 | try self.writeExportInfo(); |
| 1581 | |
| 1582 | { |
| 1583 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 1584 | const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab; |
| 1585 | symtab.symoff = @intCast(u32, seg.inner.fileoff + seg.inner.filesize); |
| 1586 | } |
| 1587 | |
| 1588 | try self.writeDebugInfo(); |
| 1589 | try self.writeSymbolTable(); |
| 1590 | try self.writeDynamicSymbolTable(); |
| 1591 | try self.writeStringTable(); |
| 1592 | |
| 1593 | { |
| 1594 | // Seal __LINKEDIT size |
| 1595 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 1596 | seg.inner.vmsize = mem.alignForwardGeneric(u64, seg.inner.filesize, self.page_size.?); |
| 1597 | } |
| 1598 | |
| 1599 | if (self.arch.? == .aarch64) { |
| 1600 | try self.writeCodeSignaturePadding(); |
| 1601 | } |
| 1602 | |
| 1603 | try self.writeLoadCommands(); |
| 1604 | try self.writeHeader(); |
| 1605 | |
| 1606 | if (self.arch.? == .aarch64) { |
| 1607 | try self.writeCodeSignature(); |
| 1608 | } |
| 1609 | |
| 1610 | if (comptime std.Target.current.isDarwin() and std.Target.current.cpu.arch == .aarch64) { |
| 1611 | try fs.cwd().copyFile(self.out_path.?, fs.cwd(), self.out_path.?, .{}); |
| 1612 | } |
| 1613 | } |
| 1614 | |
| 1615 | fn setEntryPoint(self: *Zld) !void { |
| 1616 | // TODO we should respect the -entry flag passed in by the user to set a custom |
| 1617 | // entrypoint. For now, assume default of `_main`. |
| 1618 | const seg = self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 1619 | const text = seg.sections.items[self.text_section_index.?]; |
| 1620 | const entry_sym = self.locals.get("_main") orelse return error.MissingMainEntrypoint; |
| 1621 | |
| 1622 | const name = try self.allocator.dupe(u8, "_main"); |
| 1623 | try self.exports.putNoClobber(self.allocator, name, .{ |
| 1624 | .n_strx = entry_sym.n_strx, |
| 1625 | .n_value = entry_sym.n_value, |
| 1626 | .n_type = macho.N_SECT | macho.N_EXT, |
| 1627 | .n_desc = entry_sym.n_desc, |
| 1628 | .n_sect = entry_sym.n_sect, |
| 1629 | }); |
| 1630 | |
| 1631 | const ec = &self.load_commands.items[self.main_cmd_index.?].Main; |
| 1632 | ec.entryoff = @intCast(u32, entry_sym.n_value - seg.inner.vmaddr); |
| 1633 | } |
| 1634 | |
| 1635 | fn writeRebaseInfoTable(self: *Zld) !void { |
| 1636 | const data_seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1637 | |
| 1638 | var pointers = std.ArrayList(Pointer).init(self.allocator); |
| 1639 | defer pointers.deinit(); |
| 1640 | try pointers.ensureCapacity(self.lazy_imports.items().len); |
| 1641 | |
| 1642 | if (self.la_symbol_ptr_section_index) |idx| { |
| 1643 | const sect = data_seg.sections.items[idx]; |
| 1644 | const base_offset = sect.addr - data_seg.inner.vmaddr; |
| 1645 | const segment_id = @intCast(u16, self.data_segment_cmd_index.?); |
| 1646 | for (self.lazy_imports.items()) |entry| { |
| 1647 | pointers.appendAssumeCapacity(.{ |
| 1648 | .offset = base_offset + entry.value.index * @sizeOf(u64), |
| 1649 | .segment_id = segment_id, |
| 1650 | }); |
| 1651 | } |
| 1652 | } |
| 1653 | |
| 1654 | try pointers.ensureCapacity(pointers.items.len + self.local_rebases.items.len); |
| 1655 | |
| 1656 | const nlocals = self.local_rebases.items.len; |
| 1657 | var i = nlocals; |
| 1658 | while (i > 0) : (i -= 1) { |
| 1659 | pointers.appendAssumeCapacity(self.local_rebases.items[i - 1]); |
| 1660 | } |
| 1661 | |
| 1662 | const size = try rebaseInfoSize(pointers.items); |
| 1663 | var buffer = try self.allocator.alloc(u8, @intCast(usize, size)); |
| 1664 | defer self.allocator.free(buffer); |
| 1665 | |
| 1666 | var stream = std.io.fixedBufferStream(buffer); |
| 1667 | try writeRebaseInfo(pointers.items, stream.writer()); |
| 1668 | |
| 1669 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 1670 | const dyld_info = &self.load_commands.items[self.dyld_info_cmd_index.?].DyldInfoOnly; |
| 1671 | dyld_info.rebase_off = @intCast(u32, seg.inner.fileoff); |
| 1672 | dyld_info.rebase_size = @intCast(u32, mem.alignForwardGeneric(u64, buffer.len, @sizeOf(u64))); |
| 1673 | seg.inner.filesize += dyld_info.rebase_size; |
| 1674 | |
| 1675 | log.debug("writing rebase info from 0x{x} to 0x{x}", .{ dyld_info.rebase_off, dyld_info.rebase_off + dyld_info.rebase_size }); |
| 1676 | |
| 1677 | try self.file.?.pwriteAll(buffer, dyld_info.rebase_off); |
| 1678 | } |
| 1679 | |
| 1680 | fn writeBindInfoTable(self: *Zld) !void { |
| 1681 | const data_seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1682 | |
| 1683 | var pointers = std.ArrayList(Pointer).init(self.allocator); |
| 1684 | defer pointers.deinit(); |
| 1685 | try pointers.ensureCapacity(self.nonlazy_imports.items().len + self.threadlocal_imports.items().len); |
| 1686 | |
| 1687 | if (self.got_section_index) |idx| { |
| 1688 | const sect = data_seg.sections.items[idx]; |
| 1689 | const base_offset = sect.addr - data_seg.inner.vmaddr; |
| 1690 | const segment_id = @intCast(u16, self.data_segment_cmd_index.?); |
| 1691 | for (self.nonlazy_imports.items()) |entry| { |
| 1692 | pointers.appendAssumeCapacity(.{ |
| 1693 | .offset = base_offset + entry.value.index * @sizeOf(u64), |
| 1694 | .segment_id = segment_id, |
| 1695 | .dylib_ordinal = entry.value.dylib_ordinal, |
| 1696 | .name = entry.key, |
| 1697 | }); |
| 1698 | } |
| 1699 | } |
| 1700 | |
| 1701 | if (self.tlv_section_index) |idx| { |
| 1702 | const sect = data_seg.sections.items[idx]; |
| 1703 | const base_offset = sect.addr - data_seg.inner.vmaddr; |
| 1704 | const segment_id = @intCast(u16, self.data_segment_cmd_index.?); |
| 1705 | for (self.threadlocal_imports.items()) |entry| { |
| 1706 | pointers.appendAssumeCapacity(.{ |
| 1707 | .offset = base_offset + entry.value.index * @sizeOf(u64), |
| 1708 | .segment_id = segment_id, |
| 1709 | .dylib_ordinal = entry.value.dylib_ordinal, |
| 1710 | .name = entry.key, |
| 1711 | }); |
| 1712 | } |
| 1713 | } |
| 1714 | |
| 1715 | const size = try bindInfoSize(pointers.items); |
| 1716 | var buffer = try self.allocator.alloc(u8, @intCast(usize, size)); |
| 1717 | defer self.allocator.free(buffer); |
| 1718 | |
| 1719 | var stream = std.io.fixedBufferStream(buffer); |
| 1720 | try writeBindInfo(pointers.items, stream.writer()); |
| 1721 | |
| 1722 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 1723 | const dyld_info = &self.load_commands.items[self.dyld_info_cmd_index.?].DyldInfoOnly; |
| 1724 | dyld_info.bind_off = @intCast(u32, seg.inner.fileoff + seg.inner.filesize); |
| 1725 | dyld_info.bind_size = @intCast(u32, mem.alignForwardGeneric(u64, buffer.len, @alignOf(u64))); |
| 1726 | seg.inner.filesize += dyld_info.bind_size; |
| 1727 | |
| 1728 | log.debug("writing binding info from 0x{x} to 0x{x}", .{ dyld_info.bind_off, dyld_info.bind_off + dyld_info.bind_size }); |
| 1729 | |
| 1730 | try self.file.?.pwriteAll(buffer, dyld_info.bind_off); |
| 1731 | } |
| 1732 | |
| 1733 | fn writeLazyBindInfoTable(self: *Zld) !void { |
| 1734 | const data_seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 1735 | |
| 1736 | var pointers = std.ArrayList(Pointer).init(self.allocator); |
| 1737 | defer pointers.deinit(); |
| 1738 | try pointers.ensureCapacity(self.lazy_imports.items().len); |
| 1739 | |
| 1740 | if (self.la_symbol_ptr_section_index) |idx| { |
| 1741 | const sect = data_seg.sections.items[idx]; |
| 1742 | const base_offset = sect.addr - data_seg.inner.vmaddr; |
| 1743 | const segment_id = @intCast(u16, self.data_segment_cmd_index.?); |
| 1744 | for (self.lazy_imports.items()) |entry| { |
| 1745 | pointers.appendAssumeCapacity(.{ |
| 1746 | .offset = base_offset + entry.value.index * @sizeOf(u64), |
| 1747 | .segment_id = segment_id, |
| 1748 | .dylib_ordinal = entry.value.dylib_ordinal, |
| 1749 | .name = entry.key, |
| 1750 | }); |
| 1751 | } |
| 1752 | } |
| 1753 | |
| 1754 | const size = try lazyBindInfoSize(pointers.items); |
| 1755 | var buffer = try self.allocator.alloc(u8, @intCast(usize, size)); |
| 1756 | defer self.allocator.free(buffer); |
| 1757 | |
| 1758 | var stream = std.io.fixedBufferStream(buffer); |
| 1759 | try writeLazyBindInfo(pointers.items, stream.writer()); |
| 1760 | |
| 1761 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 1762 | const dyld_info = &self.load_commands.items[self.dyld_info_cmd_index.?].DyldInfoOnly; |
| 1763 | dyld_info.lazy_bind_off = @intCast(u32, seg.inner.fileoff + seg.inner.filesize); |
| 1764 | dyld_info.lazy_bind_size = @intCast(u32, mem.alignForwardGeneric(u64, buffer.len, @alignOf(u64))); |
| 1765 | seg.inner.filesize += dyld_info.lazy_bind_size; |
| 1766 | |
| 1767 | log.debug("writing lazy binding info from 0x{x} to 0x{x}", .{ dyld_info.lazy_bind_off, dyld_info.lazy_bind_off + dyld_info.lazy_bind_size }); |
| 1768 | |
| 1769 | try self.file.?.pwriteAll(buffer, dyld_info.lazy_bind_off); |
| 1770 | try self.populateLazyBindOffsetsInStubHelper(buffer); |
| 1771 | } |
| 1772 | |
| 1773 | fn populateLazyBindOffsetsInStubHelper(self: *Zld, buffer: []const u8) !void { |
| 1774 | var stream = std.io.fixedBufferStream(buffer); |
| 1775 | var reader = stream.reader(); |
| 1776 | var offsets = std.ArrayList(u32).init(self.allocator); |
| 1777 | try offsets.append(0); |
| 1778 | defer offsets.deinit(); |
| 1779 | var valid_block = false; |
| 1780 | |
| 1781 | while (true) { |
| 1782 | const inst = reader.readByte() catch |err| switch (err) { |
| 1783 | error.EndOfStream => break, |
| 1784 | else => return err, |
| 1785 | }; |
| 1786 | const imm: u8 = inst & macho.BIND_IMMEDIATE_MASK; |
| 1787 | const opcode: u8 = inst & macho.BIND_OPCODE_MASK; |
| 1788 | |
| 1789 | switch (opcode) { |
| 1790 | macho.BIND_OPCODE_DO_BIND => { |
| 1791 | valid_block = true; |
| 1792 | }, |
| 1793 | macho.BIND_OPCODE_DONE => { |
| 1794 | if (valid_block) { |
| 1795 | const offset = try stream.getPos(); |
| 1796 | try offsets.append(@intCast(u32, offset)); |
| 1797 | } |
| 1798 | valid_block = false; |
| 1799 | }, |
| 1800 | macho.BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM => { |
| 1801 | var next = try reader.readByte(); |
| 1802 | while (next != @as(u8, 0)) { |
| 1803 | next = try reader.readByte(); |
| 1804 | } |
| 1805 | }, |
| 1806 | macho.BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB => { |
| 1807 | _ = try leb.readULEB128(u64, reader); |
| 1808 | }, |
| 1809 | macho.BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB => { |
| 1810 | _ = try leb.readULEB128(u64, reader); |
| 1811 | }, |
| 1812 | macho.BIND_OPCODE_SET_ADDEND_SLEB => { |
| 1813 | _ = try leb.readILEB128(i64, reader); |
| 1814 | }, |
| 1815 | else => {}, |
| 1816 | } |
| 1817 | } |
| 1818 | assert(self.lazy_imports.items().len <= offsets.items.len); |
| 1819 | |
| 1820 | const stub_size: u4 = switch (self.arch.?) { |
| 1821 | .x86_64 => 10, |
| 1822 | .aarch64 => 3 * @sizeOf(u32), |
| 1823 | else => unreachable, |
| 1824 | }; |
| 1825 | const off: u4 = switch (self.arch.?) { |
| 1826 | .x86_64 => 1, |
| 1827 | .aarch64 => 2 * @sizeOf(u32), |
| 1828 | else => unreachable, |
| 1829 | }; |
| 1830 | var buf: [@sizeOf(u32)]u8 = undefined; |
| 1831 | for (self.lazy_imports.items()) |entry| { |
| 1832 | const symbol = entry.value; |
| 1833 | const placeholder_off = self.stub_helper_stubs_start_off.? + symbol.index * stub_size + off; |
| 1834 | mem.writeIntLittle(u32, &buf, offsets.items[symbol.index]); |
| 1835 | try self.file.?.pwriteAll(&buf, placeholder_off); |
| 1836 | } |
| 1837 | } |
| 1838 | |
| 1839 | fn writeExportInfo(self: *Zld) !void { |
| 1840 | var trie = Trie.init(self.allocator); |
| 1841 | defer trie.deinit(); |
| 1842 | |
| 1843 | const text_segment = self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 1844 | for (self.exports.items()) |entry| { |
| 1845 | const name = entry.key; |
| 1846 | const symbol = entry.value; |
| 1847 | // TODO figure out if we should put all exports into the export trie |
| 1848 | assert(symbol.n_value >= text_segment.inner.vmaddr); |
| 1849 | try trie.put(.{ |
| 1850 | .name = name, |
| 1851 | .vmaddr_offset = symbol.n_value - text_segment.inner.vmaddr, |
| 1852 | .export_flags = macho.EXPORT_SYMBOL_FLAGS_KIND_REGULAR, |
| 1853 | }); |
| 1854 | } |
| 1855 | |
| 1856 | try trie.finalize(); |
| 1857 | var buffer = try self.allocator.alloc(u8, @intCast(usize, trie.size)); |
| 1858 | defer self.allocator.free(buffer); |
| 1859 | var stream = std.io.fixedBufferStream(buffer); |
| 1860 | const nwritten = try trie.write(stream.writer()); |
| 1861 | assert(nwritten == trie.size); |
| 1862 | |
| 1863 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 1864 | const dyld_info = &self.load_commands.items[self.dyld_info_cmd_index.?].DyldInfoOnly; |
| 1865 | dyld_info.export_off = @intCast(u32, seg.inner.fileoff + seg.inner.filesize); |
| 1866 | dyld_info.export_size = @intCast(u32, mem.alignForwardGeneric(u64, buffer.len, @alignOf(u64))); |
| 1867 | seg.inner.filesize += dyld_info.export_size; |
| 1868 | |
| 1869 | log.debug("writing export info from 0x{x} to 0x{x}", .{ dyld_info.export_off, dyld_info.export_off + dyld_info.export_size }); |
| 1870 | |
| 1871 | try self.file.?.pwriteAll(buffer, dyld_info.export_off); |
| 1872 | } |
| 1873 | |
| 1874 | fn writeDebugInfo(self: *Zld) !void { |
| 1875 | var stabs = std.ArrayList(macho.nlist_64).init(self.allocator); |
| 1876 | defer stabs.deinit(); |
| 1877 | |
| 1878 | for (self.objects.items) |object| { |
| 1879 | var debug_info = blk: { |
| 1880 | var di = try DebugInfo.parseFromObject(self.allocator, object); |
| 1881 | break :blk di orelse continue; |
| 1882 | }; |
| 1883 | defer debug_info.deinit(self.allocator); |
| 1884 | |
| 1885 | const compile_unit = try debug_info.inner.findCompileUnit(0x0); // We assume there is only one CU. |
| 1886 | const name = try compile_unit.die.getAttrString(&debug_info.inner, dwarf.AT_name); |
| 1887 | const comp_dir = try compile_unit.die.getAttrString(&debug_info.inner, dwarf.AT_comp_dir); |
| 1888 | |
| 1889 | { |
| 1890 | const tu_path = try std.fs.path.join(self.allocator, &[_][]const u8{ comp_dir, name }); |
| 1891 | defer self.allocator.free(tu_path); |
| 1892 | const dirname = std.fs.path.dirname(tu_path) orelse "./"; |
| 1893 | // Current dir |
| 1894 | try stabs.append(.{ |
| 1895 | .n_strx = try self.makeString(tu_path[0 .. dirname.len + 1]), |
| 1896 | .n_type = macho.N_SO, |
| 1897 | .n_sect = 0, |
| 1898 | .n_desc = 0, |
| 1899 | .n_value = 0, |
| 1900 | }); |
| 1901 | // Artifact name |
| 1902 | try stabs.append(.{ |
| 1903 | .n_strx = try self.makeString(tu_path[dirname.len + 1 ..]), |
| 1904 | .n_type = macho.N_SO, |
| 1905 | .n_sect = 0, |
| 1906 | .n_desc = 0, |
| 1907 | .n_value = 0, |
| 1908 | }); |
| 1909 | // Path to object file with debug info |
| 1910 | var buffer: [std.fs.MAX_PATH_BYTES]u8 = undefined; |
| 1911 | const path = object.name; |
| 1912 | const full_path = try std.os.realpath(path, &buffer); |
| 1913 | const stat = try object.file.stat(); |
| 1914 | const mtime = @intCast(u64, @divFloor(stat.mtime, 1_000_000_000)); |
| 1915 | try stabs.append(.{ |
| 1916 | .n_strx = try self.makeString(full_path), |
| 1917 | .n_type = macho.N_OSO, |
| 1918 | .n_sect = 0, |
| 1919 | .n_desc = 1, |
| 1920 | .n_value = mtime, |
| 1921 | }); |
| 1922 | } |
| 1923 | |
| 1924 | for (object.symtab.items) |source_sym| { |
| 1925 | const symname = object.getString(source_sym.n_strx); |
| 1926 | const source_addr = source_sym.n_value; |
| 1927 | const target_sym = self.locals.get(symname) orelse continue; |
| 1928 | |
| 1929 | const maybe_size = blk: for (debug_info.inner.func_list.items) |func| { |
| 1930 | if (func.pc_range) |range| { |
| 1931 | if (source_addr >= range.start and source_addr < range.end) { |
| 1932 | break :blk range.end - range.start; |
| 1933 | } |
| 1934 | } |
| 1935 | } else null; |
| 1936 | |
| 1937 | if (maybe_size) |size| { |
| 1938 | try stabs.append(.{ |
| 1939 | .n_strx = 0, |
| 1940 | .n_type = macho.N_BNSYM, |
| 1941 | .n_sect = target_sym.n_sect, |
| 1942 | .n_desc = 0, |
| 1943 | .n_value = target_sym.n_value, |
| 1944 | }); |
| 1945 | try stabs.append(.{ |
| 1946 | .n_strx = target_sym.n_strx, |
| 1947 | .n_type = macho.N_FUN, |
| 1948 | .n_sect = target_sym.n_sect, |
| 1949 | .n_desc = 0, |
| 1950 | .n_value = target_sym.n_value, |
| 1951 | }); |
| 1952 | try stabs.append(.{ |
| 1953 | .n_strx = 0, |
| 1954 | .n_type = macho.N_FUN, |
| 1955 | .n_sect = 0, |
| 1956 | .n_desc = 0, |
| 1957 | .n_value = size, |
| 1958 | }); |
| 1959 | try stabs.append(.{ |
| 1960 | .n_strx = 0, |
| 1961 | .n_type = macho.N_ENSYM, |
| 1962 | .n_sect = target_sym.n_sect, |
| 1963 | .n_desc = 0, |
| 1964 | .n_value = size, |
| 1965 | }); |
| 1966 | } else { |
| 1967 | // TODO need a way to differentiate symbols: global, static, local, etc. |
| 1968 | try stabs.append(.{ |
| 1969 | .n_strx = target_sym.n_strx, |
| 1970 | .n_type = macho.N_STSYM, |
| 1971 | .n_sect = target_sym.n_sect, |
| 1972 | .n_desc = 0, |
| 1973 | .n_value = target_sym.n_value, |
| 1974 | }); |
| 1975 | } |
| 1976 | } |
| 1977 | |
| 1978 | // Close the source file! |
| 1979 | try stabs.append(.{ |
| 1980 | .n_strx = 0, |
| 1981 | .n_type = macho.N_SO, |
| 1982 | .n_sect = 0, |
| 1983 | .n_desc = 0, |
| 1984 | .n_value = 0, |
| 1985 | }); |
| 1986 | } |
| 1987 | |
| 1988 | if (stabs.items.len == 0) return; |
| 1989 | |
| 1990 | // Write stabs into the symbol table |
| 1991 | const linkedit = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 1992 | const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab; |
| 1993 | |
| 1994 | symtab.nsyms = @intCast(u32, stabs.items.len); |
| 1995 | |
| 1996 | const stabs_off = symtab.symoff; |
| 1997 | const stabs_size = symtab.nsyms * @sizeOf(macho.nlist_64); |
| 1998 | log.debug("writing symbol stabs from 0x{x} to 0x{x}", .{ stabs_off, stabs_size + stabs_off }); |
| 1999 | try self.file.?.pwriteAll(mem.sliceAsBytes(stabs.items), stabs_off); |
| 2000 | |
| 2001 | linkedit.inner.filesize += stabs_size; |
| 2002 | |
| 2003 | // Update dynamic symbol table. |
| 2004 | const dysymtab = &self.load_commands.items[self.dysymtab_cmd_index.?].Dysymtab; |
| 2005 | dysymtab.nlocalsym = symtab.nsyms; |
| 2006 | } |
| 2007 | |
| 2008 | fn writeSymbolTable(self: *Zld) !void { |
| 2009 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 2010 | const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab; |
| 2011 | |
| 2012 | const nlocals = self.locals.items().len; |
| 2013 | var locals = std.ArrayList(macho.nlist_64).init(self.allocator); |
| 2014 | defer locals.deinit(); |
| 2015 | |
| 2016 | try locals.ensureCapacity(nlocals); |
| 2017 | for (self.locals.items()) |entry| { |
| 2018 | locals.appendAssumeCapacity(entry.value); |
| 2019 | } |
| 2020 | |
| 2021 | const nexports = self.exports.items().len; |
| 2022 | var exports = std.ArrayList(macho.nlist_64).init(self.allocator); |
| 2023 | defer exports.deinit(); |
| 2024 | |
| 2025 | try exports.ensureCapacity(nexports); |
| 2026 | for (self.exports.items()) |entry| { |
| 2027 | exports.appendAssumeCapacity(entry.value); |
| 2028 | } |
| 2029 | |
| 2030 | const nundefs = self.lazy_imports.items().len + self.nonlazy_imports.items().len + self.threadlocal_imports.items().len; |
| 2031 | var undefs = std.ArrayList(macho.nlist_64).init(self.allocator); |
| 2032 | defer undefs.deinit(); |
| 2033 | |
| 2034 | try undefs.ensureCapacity(nundefs); |
| 2035 | for (self.lazy_imports.items()) |entry| { |
| 2036 | undefs.appendAssumeCapacity(entry.value.symbol); |
| 2037 | } |
| 2038 | for (self.nonlazy_imports.items()) |entry| { |
| 2039 | undefs.appendAssumeCapacity(entry.value.symbol); |
| 2040 | } |
| 2041 | for (self.threadlocal_imports.items()) |entry| { |
| 2042 | undefs.appendAssumeCapacity(entry.value.symbol); |
| 2043 | } |
| 2044 | |
| 2045 | const locals_off = symtab.symoff + symtab.nsyms * @sizeOf(macho.nlist_64); |
| 2046 | const locals_size = nlocals * @sizeOf(macho.nlist_64); |
| 2047 | log.debug("writing local symbols from 0x{x} to 0x{x}", .{ locals_off, locals_size + locals_off }); |
| 2048 | try self.file.?.pwriteAll(mem.sliceAsBytes(locals.items), locals_off); |
| 2049 | |
| 2050 | const exports_off = locals_off + locals_size; |
| 2051 | const exports_size = nexports * @sizeOf(macho.nlist_64); |
| 2052 | log.debug("writing exported symbols from 0x{x} to 0x{x}", .{ exports_off, exports_size + exports_off }); |
| 2053 | try self.file.?.pwriteAll(mem.sliceAsBytes(exports.items), exports_off); |
| 2054 | |
| 2055 | const undefs_off = exports_off + exports_size; |
| 2056 | const undefs_size = nundefs * @sizeOf(macho.nlist_64); |
| 2057 | log.debug("writing undefined symbols from 0x{x} to 0x{x}", .{ undefs_off, undefs_size + undefs_off }); |
| 2058 | try self.file.?.pwriteAll(mem.sliceAsBytes(undefs.items), undefs_off); |
| 2059 | |
| 2060 | symtab.nsyms += @intCast(u32, nlocals + nexports + nundefs); |
| 2061 | seg.inner.filesize += locals_size + exports_size + undefs_size; |
| 2062 | |
| 2063 | // Update dynamic symbol table. |
| 2064 | const dysymtab = &self.load_commands.items[self.dysymtab_cmd_index.?].Dysymtab; |
| 2065 | dysymtab.nlocalsym += @intCast(u32, nlocals); |
| 2066 | dysymtab.iextdefsym = dysymtab.nlocalsym; |
| 2067 | dysymtab.nextdefsym = @intCast(u32, nexports); |
| 2068 | dysymtab.iundefsym = dysymtab.nlocalsym + dysymtab.nextdefsym; |
| 2069 | dysymtab.nundefsym = @intCast(u32, nundefs); |
| 2070 | } |
| 2071 | |
| 2072 | fn writeDynamicSymbolTable(self: *Zld) !void { |
| 2073 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 2074 | const text_segment = &self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 2075 | const stubs = &text_segment.sections.items[self.stubs_section_index.?]; |
| 2076 | const data_segment = &self.load_commands.items[self.data_segment_cmd_index.?].Segment; |
| 2077 | const got = &data_segment.sections.items[self.got_section_index.?]; |
| 2078 | const la_symbol_ptr = &data_segment.sections.items[self.la_symbol_ptr_section_index.?]; |
| 2079 | const dysymtab = &self.load_commands.items[self.dysymtab_cmd_index.?].Dysymtab; |
| 2080 | |
| 2081 | const lazy = self.lazy_imports.items(); |
| 2082 | const nonlazy = self.nonlazy_imports.items(); |
| 2083 | dysymtab.indirectsymoff = @intCast(u32, seg.inner.fileoff + seg.inner.filesize); |
| 2084 | dysymtab.nindirectsyms = @intCast(u32, lazy.len * 2 + nonlazy.len); |
| 2085 | const needed_size = dysymtab.nindirectsyms * @sizeOf(u32); |
| 2086 | seg.inner.filesize += needed_size; |
| 2087 | |
| 2088 | log.debug("writing indirect symbol table from 0x{x} to 0x{x}", .{ |
| 2089 | dysymtab.indirectsymoff, |
| 2090 | dysymtab.indirectsymoff + needed_size, |
| 2091 | }); |
| 2092 | |
| 2093 | var buf = try self.allocator.alloc(u8, needed_size); |
| 2094 | defer self.allocator.free(buf); |
| 2095 | var stream = std.io.fixedBufferStream(buf); |
| 2096 | var writer = stream.writer(); |
| 2097 | |
| 2098 | stubs.reserved1 = 0; |
| 2099 | for (self.lazy_imports.items()) |_, i| { |
| 2100 | const symtab_idx = @intCast(u32, dysymtab.iundefsym + i); |
| 2101 | try writer.writeIntLittle(u32, symtab_idx); |
| 2102 | } |
| 2103 | |
| 2104 | const base_id = @intCast(u32, lazy.len); |
| 2105 | got.reserved1 = base_id; |
| 2106 | for (self.nonlazy_imports.items()) |_, i| { |
| 2107 | const symtab_idx = @intCast(u32, dysymtab.iundefsym + i + base_id); |
| 2108 | try writer.writeIntLittle(u32, symtab_idx); |
| 2109 | } |
| 2110 | |
| 2111 | la_symbol_ptr.reserved1 = got.reserved1 + @intCast(u32, nonlazy.len); |
| 2112 | for (self.lazy_imports.items()) |_, i| { |
| 2113 | const symtab_idx = @intCast(u32, dysymtab.iundefsym + i); |
| 2114 | try writer.writeIntLittle(u32, symtab_idx); |
| 2115 | } |
| 2116 | |
| 2117 | try self.file.?.pwriteAll(buf, dysymtab.indirectsymoff); |
| 2118 | } |
| 2119 | |
| 2120 | fn writeStringTable(self: *Zld) !void { |
| 2121 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 2122 | const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab; |
| 2123 | symtab.stroff = @intCast(u32, seg.inner.fileoff + seg.inner.filesize); |
| 2124 | symtab.strsize = @intCast(u32, mem.alignForwardGeneric(u64, self.strtab.items.len, @alignOf(u64))); |
| 2125 | seg.inner.filesize += symtab.strsize; |
| 2126 | |
| 2127 | log.debug("writing string table from 0x{x} to 0x{x}", .{ symtab.stroff, symtab.stroff + symtab.strsize }); |
| 2128 | |
| 2129 | try self.file.?.pwriteAll(self.strtab.items, symtab.stroff); |
| 2130 | |
| 2131 | if (symtab.strsize > self.strtab.items.len and self.arch.? == .x86_64) { |
| 2132 | // This is the last section, so we need to pad it out. |
| 2133 | try self.file.?.pwriteAll(&[_]u8{0}, seg.inner.fileoff + seg.inner.filesize - 1); |
| 2134 | } |
| 2135 | } |
| 2136 | |
| 2137 | fn writeCodeSignaturePadding(self: *Zld) !void { |
| 2138 | const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment; |
| 2139 | const code_sig_cmd = &self.load_commands.items[self.code_signature_cmd_index.?].LinkeditData; |
| 2140 | const fileoff = seg.inner.fileoff + seg.inner.filesize; |
| 2141 | const needed_size = CodeSignature.calcCodeSignaturePaddingSize( |
| 2142 | self.out_path.?, |
| 2143 | fileoff, |
| 2144 | self.page_size.?, |
| 2145 | ); |
| 2146 | code_sig_cmd.dataoff = @intCast(u32, fileoff); |
| 2147 | code_sig_cmd.datasize = needed_size; |
| 2148 | |
| 2149 | // Advance size of __LINKEDIT segment |
| 2150 | seg.inner.filesize += needed_size; |
| 2151 | seg.inner.vmsize = mem.alignForwardGeneric(u64, seg.inner.filesize, self.page_size.?); |
| 2152 | |
| 2153 | log.debug("writing code signature padding from 0x{x} to 0x{x}", .{ fileoff, fileoff + needed_size }); |
| 2154 | |
| 2155 | // Pad out the space. We need to do this to calculate valid hashes for everything in the file |
| 2156 | // except for code signature data. |
| 2157 | try self.file.?.pwriteAll(&[_]u8{0}, fileoff + needed_size - 1); |
| 2158 | } |
| 2159 | |
| 2160 | fn writeCodeSignature(self: *Zld) !void { |
| 2161 | const text_seg = self.load_commands.items[self.text_segment_cmd_index.?].Segment; |
| 2162 | const code_sig_cmd = self.load_commands.items[self.code_signature_cmd_index.?].LinkeditData; |
| 2163 | |
| 2164 | var code_sig = CodeSignature.init(self.allocator, self.page_size.?); |
| 2165 | defer code_sig.deinit(); |
| 2166 | try code_sig.calcAdhocSignature( |
| 2167 | self.file.?, |
| 2168 | self.out_path.?, |
| 2169 | text_seg.inner, |
| 2170 | code_sig_cmd, |
| 2171 | .Exe, |
| 2172 | ); |
| 2173 | |
| 2174 | var buffer = try self.allocator.alloc(u8, code_sig.size()); |
| 2175 | defer self.allocator.free(buffer); |
| 2176 | var stream = std.io.fixedBufferStream(buffer); |
| 2177 | try code_sig.write(stream.writer()); |
| 2178 | |
| 2179 | log.debug("writing code signature from 0x{x} to 0x{x}", .{ code_sig_cmd.dataoff, code_sig_cmd.dataoff + buffer.len }); |
| 2180 | |
| 2181 | try self.file.?.pwriteAll(buffer, code_sig_cmd.dataoff); |
| 2182 | } |
| 2183 | |
| 2184 | fn writeLoadCommands(self: *Zld) !void { |
| 2185 | var sizeofcmds: u32 = 0; |
| 2186 | for (self.load_commands.items) |lc| { |
| 2187 | sizeofcmds += lc.cmdsize(); |
| 2188 | } |
| 2189 | |
| 2190 | var buffer = try self.allocator.alloc(u8, sizeofcmds); |
| 2191 | defer self.allocator.free(buffer); |
| 2192 | var writer = std.io.fixedBufferStream(buffer).writer(); |
| 2193 | for (self.load_commands.items) |lc| { |
| 2194 | try lc.write(writer); |
| 2195 | } |
| 2196 | |
| 2197 | const off = @sizeOf(macho.mach_header_64); |
| 2198 | log.debug("writing {} load commands from 0x{x} to 0x{x}", .{ self.load_commands.items.len, off, off + sizeofcmds }); |
| 2199 | try self.file.?.pwriteAll(buffer, off); |
| 2200 | } |
| 2201 | |
| 2202 | fn writeHeader(self: *Zld) !void { |
| 2203 | var header: macho.mach_header_64 = undefined; |
| 2204 | header.magic = macho.MH_MAGIC_64; |
| 2205 | |
| 2206 | const CpuInfo = struct { |
| 2207 | cpu_type: macho.cpu_type_t, |
| 2208 | cpu_subtype: macho.cpu_subtype_t, |
| 2209 | }; |
| 2210 | |
| 2211 | const cpu_info: CpuInfo = switch (self.arch.?) { |
| 2212 | .aarch64 => .{ |
| 2213 | .cpu_type = macho.CPU_TYPE_ARM64, |
| 2214 | .cpu_subtype = macho.CPU_SUBTYPE_ARM_ALL, |
| 2215 | }, |
| 2216 | .x86_64 => .{ |
| 2217 | .cpu_type = macho.CPU_TYPE_X86_64, |
| 2218 | .cpu_subtype = macho.CPU_SUBTYPE_X86_64_ALL, |
| 2219 | }, |
| 2220 | else => return error.UnsupportedCpuArchitecture, |
| 2221 | }; |
| 2222 | header.cputype = cpu_info.cpu_type; |
| 2223 | header.cpusubtype = cpu_info.cpu_subtype; |
| 2224 | header.filetype = macho.MH_EXECUTE; |
| 2225 | header.flags = macho.MH_NOUNDEFS | macho.MH_DYLDLINK | macho.MH_PIE | macho.MH_TWOLEVEL; |
| 2226 | header.reserved = 0; |
| 2227 | |
| 2228 | if (self.tlv_section_index) |_| |
| 2229 | header.flags |= macho.MH_HAS_TLV_DESCRIPTORS; |
| 2230 | |
| 2231 | header.ncmds = @intCast(u32, self.load_commands.items.len); |
| 2232 | header.sizeofcmds = 0; |
| 2233 | for (self.load_commands.items) |cmd| { |
| 2234 | header.sizeofcmds += cmd.cmdsize(); |
| 2235 | } |
| 2236 | log.debug("writing Mach-O header {}", .{header}); |
| 2237 | try self.file.?.pwriteAll(mem.asBytes(&header), 0); |
| 2238 | } |
| 2239 | |
| 2240 | pub fn makeStaticString(bytes: []const u8) [16]u8 { |
| 2241 | var buf = [_]u8{0} ** 16; |
| 2242 | assert(bytes.len <= buf.len); |
| 2243 | mem.copy(u8, &buf, bytes); |
| 2244 | return buf; |
| 2245 | } |
| 2246 | |
| 2247 | fn makeString(self: *Zld, bytes: []const u8) !u32 { |
| 2248 | try self.strtab.ensureCapacity(self.allocator, self.strtab.items.len + bytes.len + 1); |
| 2249 | const offset = @intCast(u32, self.strtab.items.len); |
| 2250 | log.debug("writing new string '{s}' into string table at offset 0x{x}", .{ bytes, offset }); |
| 2251 | self.strtab.appendSliceAssumeCapacity(bytes); |
| 2252 | self.strtab.appendAssumeCapacity(0); |
| 2253 | return offset; |
| 2254 | } |
| 2255 | |
| 2256 | fn getString(self: *const Zld, str_off: u32) []const u8 { |
| 2257 | assert(str_off < self.strtab.items.len); |
| 2258 | return mem.spanZ(@ptrCast([*:0]const u8, self.strtab.items.ptr + str_off)); |
| 2259 | } |
| 2260 | |
| 2261 | pub fn parseName(name: *const [16]u8) []const u8 { |
| 2262 | const len = mem.indexOfScalar(u8, name, @as(u8, 0)) orelse name.len; |
| 2263 | return name[0..len]; |
| 2264 | } |
| 2265 | |
| 2266 | fn addSegmentToDir(self: *Zld, idx: u16) !void { |
| 2267 | const segment_cmd = self.load_commands.items[idx].Segment; |
| 2268 | return self.segments_directory.putNoClobber(self.allocator, segment_cmd.inner.segname, idx); |
| 2269 | } |
| 2270 | |
| 2271 | fn addSectionToDir(self: *Zld, value: DirectoryEntry) !void { |
| 2272 | const seg = self.load_commands.items[value.seg_index].Segment; |
| 2273 | const sect = seg.sections.items[value.sect_index]; |
| 2274 | return self.directory.putNoClobber(self.allocator, .{ |
| 2275 | .segname = sect.segname, |
| 2276 | .sectname = sect.sectname, |
| 2277 | }, value); |
| 2278 | } |
| 2279 | |
| 2280 | fn isLocal(sym: *const macho.nlist_64) callconv(.Inline) bool { |
| 2281 | if (isExtern(sym)) return false; |
| 2282 | const tt = macho.N_TYPE & sym.n_type; |
| 2283 | return tt == macho.N_SECT; |
| 2284 | } |
| 2285 | |
| 2286 | fn isExport(sym: *const macho.nlist_64) callconv(.Inline) bool { |
| 2287 | if (!isExtern(sym)) return false; |
| 2288 | const tt = macho.N_TYPE & sym.n_type; |
| 2289 | return tt == macho.N_SECT; |
| 2290 | } |
| 2291 | |
| 2292 | fn isImport(sym: *const macho.nlist_64) callconv(.Inline) bool { |
| 2293 | if (!isExtern(sym)) return false; |
| 2294 | const tt = macho.N_TYPE & sym.n_type; |
| 2295 | return tt == macho.N_UNDF; |
| 2296 | } |
| 2297 | |
| 2298 | fn isExtern(sym: *const macho.nlist_64) callconv(.Inline) bool { |
| 2299 | if ((sym.n_type & macho.N_EXT) == 0) return false; |
| 2300 | return (sym.n_type & macho.N_PEXT) == 0; |
| 2301 | } |
Jakub Konka <kubkon@jakubkonka.com> 2021-02-23 23:45:36+01:00