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| 1 | | //! The main driver of the self-hosted COFF linker. |
| 2 | | const Coff = @This(); |
| 3 | | |
| 4 | | const std = @import("std"); |
| 5 | | const build_options = @import("build_options"); |
| 6 | | const builtin = @import("builtin"); |
| 7 | | const assert = std.debug.assert; |
| 8 | | const coff_util = std.coff; |
| 9 | | const fmt = std.fmt; |
| 10 | | const fs = std.fs; |
| 11 | | const log = std.log.scoped(.link); |
| 12 | | const math = std.math; |
| 13 | | const mem = std.mem; |
| 14 | | |
| 15 | | const Allocator = std.mem.Allocator; |
| 16 | | const Path = std.Build.Cache.Path; |
| 17 | | const Directory = std.Build.Cache.Directory; |
| 18 | | const Cache = std.Build.Cache; |
| 19 | | |
| 20 | | const aarch64_util = link.aarch64; |
| 21 | | const allocPrint = std.fmt.allocPrint; |
| 22 | | const codegen = @import("../codegen.zig"); |
| 23 | | const link = @import("../link.zig"); |
| 24 | | const target_util = @import("../target.zig"); |
| 25 | | const trace = @import("../tracy.zig").trace; |
| 26 | | |
| 27 | | const Compilation = @import("../Compilation.zig"); |
| 28 | | const Zcu = @import("../Zcu.zig"); |
| 29 | | const InternPool = @import("../InternPool.zig"); |
| 30 | | const TableSection = @import("table_section.zig").TableSection; |
| 31 | | const StringTable = @import("StringTable.zig"); |
| 32 | | const Type = @import("../Type.zig"); |
| 33 | | const Value = @import("../Value.zig"); |
| 34 | | const AnalUnit = InternPool.AnalUnit; |
| 35 | | const dev = @import("../dev.zig"); |
| 36 | | |
| 37 | | base: link.File, |
| 38 | | image_base: u64, |
| 39 | | /// TODO this and minor_subsystem_version should be combined into one property and left as |
| 40 | | /// default or populated together. They should not be separate fields. |
| 41 | | major_subsystem_version: u16, |
| 42 | | minor_subsystem_version: u16, |
| 43 | | entry: link.File.OpenOptions.Entry, |
| 44 | | entry_addr: ?u32, |
| 45 | | module_definition_file: ?[]const u8, |
| 46 | | repro: bool, |
| 47 | | |
| 48 | | ptr_width: PtrWidth, |
| 49 | | page_size: u32, |
| 50 | | |
| 51 | | sections: std.MultiArrayList(Section) = .{}, |
| 52 | | data_directories: [coff_util.IMAGE_NUMBEROF_DIRECTORY_ENTRIES]coff_util.ImageDataDirectory, |
| 53 | | |
| 54 | | text_section_index: ?u16 = null, |
| 55 | | got_section_index: ?u16 = null, |
| 56 | | rdata_section_index: ?u16 = null, |
| 57 | | data_section_index: ?u16 = null, |
| 58 | | reloc_section_index: ?u16 = null, |
| 59 | | idata_section_index: ?u16 = null, |
| 60 | | |
| 61 | | locals: std.ArrayListUnmanaged(coff_util.Symbol) = .empty, |
| 62 | | globals: std.ArrayListUnmanaged(SymbolWithLoc) = .empty, |
| 63 | | resolver: std.StringHashMapUnmanaged(u32) = .empty, |
| 64 | | unresolved: std.AutoArrayHashMapUnmanaged(u32, bool) = .empty, |
| 65 | | need_got_table: std.AutoHashMapUnmanaged(u32, void) = .empty, |
| 66 | | |
| 67 | | locals_free_list: std.ArrayListUnmanaged(u32) = .empty, |
| 68 | | globals_free_list: std.ArrayListUnmanaged(u32) = .empty, |
| 69 | | |
| 70 | | strtab: StringTable = .{}, |
| 71 | | strtab_offset: ?u32 = null, |
| 72 | | |
| 73 | | temp_strtab: StringTable = .{}, |
| 74 | | |
| 75 | | got_table: TableSection(SymbolWithLoc) = .{}, |
| 76 | | |
| 77 | | /// A table of ImportTables partitioned by the library name. |
| 78 | | /// Key is an offset into the interning string table `temp_strtab`. |
| 79 | | import_tables: std.AutoArrayHashMapUnmanaged(u32, ImportTable) = .empty, |
| 80 | | |
| 81 | | got_table_count_dirty: bool = true, |
| 82 | | got_table_contents_dirty: bool = true, |
| 83 | | imports_count_dirty: bool = true, |
| 84 | | |
| 85 | | /// Table of tracked LazySymbols. |
| 86 | | lazy_syms: LazySymbolTable = .{}, |
| 87 | | |
| 88 | | /// Table of tracked `Nav`s. |
| 89 | | navs: NavTable = .{}, |
| 90 | | |
| 91 | | /// List of atoms that are either synthetic or map directly to the Zig source program. |
| 92 | | atoms: std.ArrayListUnmanaged(Atom) = .empty, |
| 93 | | |
| 94 | | /// Table of atoms indexed by the symbol index. |
| 95 | | atom_by_index_table: std.AutoHashMapUnmanaged(u32, Atom.Index) = .empty, |
| 96 | | |
| 97 | | uavs: UavTable = .{}, |
| 98 | | |
| 99 | | /// A table of relocations indexed by the owning them `Atom`. |
| 100 | | /// Note that once we refactor `Atom`'s lifetime and ownership rules, |
| 101 | | /// this will be a table indexed by index into the list of Atoms. |
| 102 | | relocs: RelocTable = .{}, |
| 103 | | |
| 104 | | /// A table of base relocations indexed by the owning them `Atom`. |
| 105 | | /// Note that once we refactor `Atom`'s lifetime and ownership rules, |
| 106 | | /// this will be a table indexed by index into the list of Atoms. |
| 107 | | base_relocs: BaseRelocationTable = .{}, |
| 108 | | |
| 109 | | /// Hot-code swapping state. |
| 110 | | hot_state: if (is_hot_update_compatible) HotUpdateState else struct {} = .{}, |
| 111 | | |
| 112 | | const is_hot_update_compatible = switch (builtin.target.os.tag) { |
| 113 | | .windows => true, |
| 114 | | else => false, |
| 115 | | }; |
| 116 | | |
| 117 | | const HotUpdateState = struct { |
| 118 | | /// Base address at which the process (image) got loaded. |
| 119 | | /// We need this info to correctly slide pointers when relocating. |
| 120 | | loaded_base_address: ?std.os.windows.HMODULE = null, |
| 121 | | }; |
| 122 | | |
| 123 | | const NavTable = std.AutoArrayHashMapUnmanaged(InternPool.Nav.Index, AvMetadata); |
| 124 | | const UavTable = std.AutoHashMapUnmanaged(InternPool.Index, AvMetadata); |
| 125 | | const RelocTable = std.AutoArrayHashMapUnmanaged(Atom.Index, std.ArrayListUnmanaged(Relocation)); |
| 126 | | const BaseRelocationTable = std.AutoArrayHashMapUnmanaged(Atom.Index, std.ArrayListUnmanaged(u32)); |
| 127 | | |
| 128 | | pub const default_file_alignment: u16 = 0x200; |
| 129 | | pub const default_size_of_stack_reserve: u32 = 0x1000000; |
| 130 | | pub const default_size_of_stack_commit: u32 = 0x1000; |
| 131 | | pub const default_size_of_heap_reserve: u32 = 0x100000; |
| 132 | | pub const default_size_of_heap_commit: u32 = 0x1000; |
| 133 | | |
| 134 | | const Section = struct { |
| 135 | | header: coff_util.SectionHeader, |
| 136 | | |
| 137 | | last_atom_index: ?Atom.Index = null, |
| 138 | | |
| 139 | | /// A list of atoms that have surplus capacity. This list can have false |
| 140 | | /// positives, as functions grow and shrink over time, only sometimes being added |
| 141 | | /// or removed from the freelist. |
| 142 | | /// |
| 143 | | /// An atom has surplus capacity when its overcapacity value is greater than |
| 144 | | /// padToIdeal(minimum_atom_size). That is, when it has so |
| 145 | | /// much extra capacity, that we could fit a small new symbol in it, itself with |
| 146 | | /// ideal_capacity or more. |
| 147 | | /// |
| 148 | | /// Ideal capacity is defined by size + (size / ideal_factor). |
| 149 | | /// |
| 150 | | /// Overcapacity is measured by actual_capacity - ideal_capacity. Note that |
| 151 | | /// overcapacity can be negative. A simple way to have negative overcapacity is to |
| 152 | | /// allocate a fresh atom, which will have ideal capacity, and then grow it |
| 153 | | /// by 1 byte. It will then have -1 overcapacity. |
| 154 | | free_list: std.ArrayListUnmanaged(Atom.Index) = .empty, |
| 155 | | }; |
| 156 | | |
| 157 | | const LazySymbolTable = std.AutoArrayHashMapUnmanaged(InternPool.Index, LazySymbolMetadata); |
| 158 | | |
| 159 | | const LazySymbolMetadata = struct { |
| 160 | | const State = enum { unused, pending_flush, flushed }; |
| 161 | | text_atom: Atom.Index = undefined, |
| 162 | | rdata_atom: Atom.Index = undefined, |
| 163 | | text_state: State = .unused, |
| 164 | | rdata_state: State = .unused, |
| 165 | | }; |
| 166 | | |
| 167 | | const AvMetadata = struct { |
| 168 | | atom: Atom.Index, |
| 169 | | section: u16, |
| 170 | | /// A list of all exports aliases of this Decl. |
| 171 | | exports: std.ArrayListUnmanaged(u32) = .empty, |
| 172 | | |
| 173 | | fn deinit(m: *AvMetadata, allocator: Allocator) void { |
| 174 | | m.exports.deinit(allocator); |
| 175 | | } |
| 176 | | |
| 177 | | fn getExport(m: AvMetadata, coff: *const Coff, name: []const u8) ?u32 { |
| 178 | | for (m.exports.items) |exp| { |
| 179 | | if (mem.eql(u8, name, coff.getSymbolName(.{ |
| 180 | | .sym_index = exp, |
| 181 | | .file = null, |
| 182 | | }))) return exp; |
| 183 | | } |
| 184 | | return null; |
| 185 | | } |
| 186 | | |
| 187 | | fn getExportPtr(m: *AvMetadata, coff: *Coff, name: []const u8) ?*u32 { |
| 188 | | for (m.exports.items) |*exp| { |
| 189 | | if (mem.eql(u8, name, coff.getSymbolName(.{ |
| 190 | | .sym_index = exp.*, |
| 191 | | .file = null, |
| 192 | | }))) return exp; |
| 193 | | } |
| 194 | | return null; |
| 195 | | } |
| 196 | | }; |
| 197 | | |
| 198 | | pub const PtrWidth = enum { |
| 199 | | p32, |
| 200 | | p64, |
| 201 | | |
| 202 | | /// Size in bytes. |
| 203 | | pub fn size(pw: PtrWidth) u4 { |
| 204 | | return switch (pw) { |
| 205 | | .p32 => 4, |
| 206 | | .p64 => 8, |
| 207 | | }; |
| 208 | | } |
| 209 | | }; |
| 210 | | |
| 211 | | pub const SymbolWithLoc = struct { |
| 212 | | // Index into the respective symbol table. |
| 213 | | sym_index: u32, |
| 214 | | |
| 215 | | // null means it's a synthetic global or Zig source. |
| 216 | | file: ?u32 = null, |
| 217 | | |
| 218 | | pub fn eql(this: SymbolWithLoc, other: SymbolWithLoc) bool { |
| 219 | | if (this.file == null and other.file == null) { |
| 220 | | return this.sym_index == other.sym_index; |
| 221 | | } |
| 222 | | if (this.file != null and other.file != null) { |
| 223 | | return this.sym_index == other.sym_index and this.file.? == other.file.?; |
| 224 | | } |
| 225 | | return false; |
| 226 | | } |
| 227 | | }; |
| 228 | | |
| 229 | | /// When allocating, the ideal_capacity is calculated by |
| 230 | | /// actual_capacity + (actual_capacity / ideal_factor) |
| 231 | | const ideal_factor = 3; |
| 232 | | |
| 233 | | /// In order for a slice of bytes to be considered eligible to keep metadata pointing at |
| 234 | | /// it as a possible place to put new symbols, it must have enough room for this many bytes |
| 235 | | /// (plus extra for reserved capacity). |
| 236 | | const minimum_text_block_size = 64; |
| 237 | | pub const min_text_capacity = padToIdeal(minimum_text_block_size); |
| 238 | | |
| 239 | | pub fn createEmpty( |
| 240 | | arena: Allocator, |
| 241 | | comp: *Compilation, |
| 242 | | emit: Path, |
| 243 | | options: link.File.OpenOptions, |
| 244 | | ) !*Coff { |
| 245 | | const target = &comp.root_mod.resolved_target.result; |
| 246 | | assert(target.ofmt == .coff); |
| 247 | | const optimize_mode = comp.root_mod.optimize_mode; |
| 248 | | const output_mode = comp.config.output_mode; |
| 249 | | const link_mode = comp.config.link_mode; |
| 250 | | const use_llvm = comp.config.use_llvm; |
| 251 | | |
| 252 | | const ptr_width: PtrWidth = switch (target.ptrBitWidth()) { |
| 253 | | 0...32 => .p32, |
| 254 | | 33...64 => .p64, |
| 255 | | else => return error.UnsupportedCOFFArchitecture, |
| 256 | | }; |
| 257 | | const page_size: u32 = switch (target.cpu.arch) { |
| 258 | | else => 0x1000, |
| 259 | | }; |
| 260 | | |
| 261 | | const coff = try arena.create(Coff); |
| 262 | | coff.* = .{ |
| 263 | | .base = .{ |
| 264 | | .tag = .coff, |
| 265 | | .comp = comp, |
| 266 | | .emit = emit, |
| 267 | | .zcu_object_basename = if (use_llvm) |
| 268 | | try std.fmt.allocPrint(arena, "{s}_zcu.obj", .{fs.path.stem(emit.sub_path)}) |
| 269 | | else |
| 270 | | null, |
| 271 | | .stack_size = options.stack_size orelse 16777216, |
| 272 | | .gc_sections = options.gc_sections orelse (optimize_mode != .Debug), |
| 273 | | .print_gc_sections = options.print_gc_sections, |
| 274 | | .allow_shlib_undefined = options.allow_shlib_undefined orelse false, |
| 275 | | .file = null, |
| 276 | | .build_id = options.build_id, |
| 277 | | }, |
| 278 | | .ptr_width = ptr_width, |
| 279 | | .page_size = page_size, |
| 280 | | |
| 281 | | .data_directories = [1]coff_util.ImageDataDirectory{.{ |
| 282 | | .virtual_address = 0, |
| 283 | | .size = 0, |
| 284 | | }} ** coff_util.IMAGE_NUMBEROF_DIRECTORY_ENTRIES, |
| 285 | | |
| 286 | | .image_base = options.image_base orelse switch (output_mode) { |
| 287 | | .Exe => switch (target.cpu.arch) { |
| 288 | | .aarch64, .x86_64 => 0x140000000, |
| 289 | | .thumb, .x86 => 0x400000, |
| 290 | | else => unreachable, |
| 291 | | }, |
| 292 | | .Lib => switch (target.cpu.arch) { |
| 293 | | .aarch64, .x86_64 => 0x180000000, |
| 294 | | .thumb, .x86 => 0x10000000, |
| 295 | | else => unreachable, |
| 296 | | }, |
| 297 | | .Obj => 0, |
| 298 | | }, |
| 299 | | |
| 300 | | .entry = options.entry, |
| 301 | | |
| 302 | | .major_subsystem_version = options.major_subsystem_version orelse 6, |
| 303 | | .minor_subsystem_version = options.minor_subsystem_version orelse 0, |
| 304 | | .entry_addr = math.cast(u32, options.entry_addr orelse 0) orelse |
| 305 | | return error.EntryAddressTooBig, |
| 306 | | .module_definition_file = options.module_definition_file, |
| 307 | | .repro = options.repro, |
| 308 | | }; |
| 309 | | errdefer coff.base.destroy(); |
| 310 | | |
| 311 | | coff.base.file = try emit.root_dir.handle.createFile(emit.sub_path, .{ |
| 312 | | .truncate = true, |
| 313 | | .read = true, |
| 314 | | .mode = link.File.determineMode(output_mode, link_mode), |
| 315 | | }); |
| 316 | | |
| 317 | | const gpa = comp.gpa; |
| 318 | | |
| 319 | | try coff.strtab.buffer.ensureUnusedCapacity(gpa, @sizeOf(u32)); |
| 320 | | coff.strtab.buffer.appendNTimesAssumeCapacity(0, @sizeOf(u32)); |
| 321 | | |
| 322 | | try coff.temp_strtab.buffer.append(gpa, 0); |
| 323 | | |
| 324 | | // Index 0 is always a null symbol. |
| 325 | | try coff.locals.append(gpa, .{ |
| 326 | | .name = [_]u8{0} ** 8, |
| 327 | | .value = 0, |
| 328 | | .section_number = .UNDEFINED, |
| 329 | | .type = .{ .base_type = .NULL, .complex_type = .NULL }, |
| 330 | | .storage_class = .NULL, |
| 331 | | .number_of_aux_symbols = 0, |
| 332 | | }); |
| 333 | | |
| 334 | | if (coff.text_section_index == null) { |
| 335 | | const file_size: u32 = @intCast(options.program_code_size_hint); |
| 336 | | coff.text_section_index = try coff.allocateSection(".text", file_size, .{ |
| 337 | | .CNT_CODE = true, |
| 338 | | .MEM_EXECUTE = true, |
| 339 | | .MEM_READ = true, |
| 340 | | }); |
| 341 | | } |
| 342 | | |
| 343 | | if (coff.got_section_index == null) { |
| 344 | | const file_size = @as(u32, @intCast(options.symbol_count_hint)) * coff.ptr_width.size(); |
| 345 | | coff.got_section_index = try coff.allocateSection(".got", file_size, .{ |
| 346 | | .CNT_INITIALIZED_DATA = true, |
| 347 | | .MEM_READ = true, |
| 348 | | }); |
| 349 | | } |
| 350 | | |
| 351 | | if (coff.rdata_section_index == null) { |
| 352 | | const file_size: u32 = coff.page_size; |
| 353 | | coff.rdata_section_index = try coff.allocateSection(".rdata", file_size, .{ |
| 354 | | .CNT_INITIALIZED_DATA = true, |
| 355 | | .MEM_READ = true, |
| 356 | | }); |
| 357 | | } |
| 358 | | |
| 359 | | if (coff.data_section_index == null) { |
| 360 | | const file_size: u32 = coff.page_size; |
| 361 | | coff.data_section_index = try coff.allocateSection(".data", file_size, .{ |
| 362 | | .CNT_INITIALIZED_DATA = true, |
| 363 | | .MEM_READ = true, |
| 364 | | .MEM_WRITE = true, |
| 365 | | }); |
| 366 | | } |
| 367 | | |
| 368 | | if (coff.idata_section_index == null) { |
| 369 | | const file_size = @as(u32, @intCast(options.symbol_count_hint)) * coff.ptr_width.size(); |
| 370 | | coff.idata_section_index = try coff.allocateSection(".idata", file_size, .{ |
| 371 | | .CNT_INITIALIZED_DATA = true, |
| 372 | | .MEM_READ = true, |
| 373 | | }); |
| 374 | | } |
| 375 | | |
| 376 | | if (coff.reloc_section_index == null) { |
| 377 | | const file_size = @as(u32, @intCast(options.symbol_count_hint)) * @sizeOf(coff_util.BaseRelocation); |
| 378 | | coff.reloc_section_index = try coff.allocateSection(".reloc", file_size, .{ |
| 379 | | .CNT_INITIALIZED_DATA = true, |
| 380 | | .MEM_DISCARDABLE = true, |
| 381 | | .MEM_READ = true, |
| 382 | | }); |
| 383 | | } |
| 384 | | |
| 385 | | if (coff.strtab_offset == null) { |
| 386 | | const file_size = @as(u32, @intCast(coff.strtab.buffer.items.len)); |
| 387 | | coff.strtab_offset = coff.findFreeSpace(file_size, @alignOf(u32)); // 4bytes aligned seems like a good idea here |
| 388 | | log.debug("found strtab free space 0x{x} to 0x{x}", .{ coff.strtab_offset.?, coff.strtab_offset.? + file_size }); |
| 389 | | } |
| 390 | | |
| 391 | | { |
| 392 | | // We need to find out what the max file offset is according to section headers. |
| 393 | | // Otherwise, we may end up with an COFF binary with file size not matching the final section's |
| 394 | | // offset + it's filesize. |
| 395 | | // TODO I don't like this here one bit |
| 396 | | var max_file_offset: u64 = 0; |
| 397 | | for (coff.sections.items(.header)) |header| { |
| 398 | | if (header.pointer_to_raw_data + header.size_of_raw_data > max_file_offset) { |
| 399 | | max_file_offset = header.pointer_to_raw_data + header.size_of_raw_data; |
| 400 | | } |
| 401 | | } |
| 402 | | try coff.pwriteAll(&[_]u8{0}, max_file_offset); |
| 403 | | } |
| 404 | | |
| 405 | | return coff; |
| 406 | | } |
| 407 | | |
| 408 | | pub fn open( |
| 409 | | arena: Allocator, |
| 410 | | comp: *Compilation, |
| 411 | | emit: Path, |
| 412 | | options: link.File.OpenOptions, |
| 413 | | ) !*Coff { |
| 414 | | // TODO: restore saved linker state, don't truncate the file, and |
| 415 | | // participate in incremental compilation. |
| 416 | | return createEmpty(arena, comp, emit, options); |
| 417 | | } |
| 418 | | |
| 419 | | pub fn deinit(coff: *Coff) void { |
| 420 | | const gpa = coff.base.comp.gpa; |
| 421 | | |
| 422 | | for (coff.sections.items(.free_list)) |*free_list| { |
| 423 | | free_list.deinit(gpa); |
| 424 | | } |
| 425 | | coff.sections.deinit(gpa); |
| 426 | | |
| 427 | | coff.atoms.deinit(gpa); |
| 428 | | coff.locals.deinit(gpa); |
| 429 | | coff.globals.deinit(gpa); |
| 430 | | |
| 431 | | { |
| 432 | | var it = coff.resolver.keyIterator(); |
| 433 | | while (it.next()) |key_ptr| { |
| 434 | | gpa.free(key_ptr.*); |
| 435 | | } |
| 436 | | coff.resolver.deinit(gpa); |
| 437 | | } |
| 438 | | |
| 439 | | coff.unresolved.deinit(gpa); |
| 440 | | coff.need_got_table.deinit(gpa); |
| 441 | | coff.locals_free_list.deinit(gpa); |
| 442 | | coff.globals_free_list.deinit(gpa); |
| 443 | | coff.strtab.deinit(gpa); |
| 444 | | coff.temp_strtab.deinit(gpa); |
| 445 | | coff.got_table.deinit(gpa); |
| 446 | | |
| 447 | | for (coff.import_tables.values()) |*itab| { |
| 448 | | itab.deinit(gpa); |
| 449 | | } |
| 450 | | coff.import_tables.deinit(gpa); |
| 451 | | |
| 452 | | coff.lazy_syms.deinit(gpa); |
| 453 | | |
| 454 | | for (coff.navs.values()) |*metadata| { |
| 455 | | metadata.deinit(gpa); |
| 456 | | } |
| 457 | | coff.navs.deinit(gpa); |
| 458 | | |
| 459 | | coff.atom_by_index_table.deinit(gpa); |
| 460 | | |
| 461 | | { |
| 462 | | var it = coff.uavs.iterator(); |
| 463 | | while (it.next()) |entry| { |
| 464 | | entry.value_ptr.exports.deinit(gpa); |
| 465 | | } |
| 466 | | coff.uavs.deinit(gpa); |
| 467 | | } |
| 468 | | |
| 469 | | for (coff.relocs.values()) |*relocs| { |
| 470 | | relocs.deinit(gpa); |
| 471 | | } |
| 472 | | coff.relocs.deinit(gpa); |
| 473 | | |
| 474 | | for (coff.base_relocs.values()) |*relocs| { |
| 475 | | relocs.deinit(gpa); |
| 476 | | } |
| 477 | | coff.base_relocs.deinit(gpa); |
| 478 | | } |
| 479 | | |
| 480 | | fn allocateSection(coff: *Coff, name: []const u8, size: u32, flags: coff_util.SectionHeader.Flags) !u16 { |
| 481 | | const index = @as(u16, @intCast(coff.sections.slice().len)); |
| 482 | | const off = coff.findFreeSpace(size, default_file_alignment); |
| 483 | | // Memory is always allocated in sequence |
| 484 | | // TODO: investigate if we can allocate .text last; this way it would never need to grow in memory! |
| 485 | | const vaddr = blk: { |
| 486 | | if (index == 0) break :blk coff.page_size; |
| 487 | | const prev_header = coff.sections.items(.header)[index - 1]; |
| 488 | | break :blk mem.alignForward(u32, prev_header.virtual_address + prev_header.virtual_size, coff.page_size); |
| 489 | | }; |
| 490 | | // We commit more memory than needed upfront so that we don't have to reallocate too soon. |
| 491 | | const memsz = mem.alignForward(u32, size, coff.page_size) * 100; |
| 492 | | log.debug("found {s} free space 0x{x} to 0x{x} (0x{x} - 0x{x})", .{ |
| 493 | | name, |
| 494 | | off, |
| 495 | | off + size, |
| 496 | | vaddr, |
| 497 | | vaddr + size, |
| 498 | | }); |
| 499 | | var header = coff_util.SectionHeader{ |
| 500 | | .name = undefined, |
| 501 | | .virtual_size = memsz, |
| 502 | | .virtual_address = vaddr, |
| 503 | | .size_of_raw_data = size, |
| 504 | | .pointer_to_raw_data = off, |
| 505 | | .pointer_to_relocations = 0, |
| 506 | | .pointer_to_linenumbers = 0, |
| 507 | | .number_of_relocations = 0, |
| 508 | | .number_of_linenumbers = 0, |
| 509 | | .flags = flags, |
| 510 | | }; |
| 511 | | const gpa = coff.base.comp.gpa; |
| 512 | | try coff.setSectionName(&header, name); |
| 513 | | try coff.sections.append(gpa, .{ .header = header }); |
| 514 | | return index; |
| 515 | | } |
| 516 | | |
| 517 | | fn growSection(coff: *Coff, sect_id: u32, needed_size: u32) !void { |
| 518 | | const header = &coff.sections.items(.header)[sect_id]; |
| 519 | | const maybe_last_atom_index = coff.sections.items(.last_atom_index)[sect_id]; |
| 520 | | const sect_capacity = coff.allocatedSize(header.pointer_to_raw_data); |
| 521 | | |
| 522 | | if (needed_size > sect_capacity) { |
| 523 | | const new_offset = coff.findFreeSpace(needed_size, default_file_alignment); |
| 524 | | const current_size = if (maybe_last_atom_index) |last_atom_index| blk: { |
| 525 | | const last_atom = coff.getAtom(last_atom_index); |
| 526 | | const sym = last_atom.getSymbol(coff); |
| 527 | | break :blk (sym.value + last_atom.size) - header.virtual_address; |
| 528 | | } else 0; |
| 529 | | log.debug("moving {s} from 0x{x} to 0x{x}", .{ |
| 530 | | coff.getSectionName(header), |
| 531 | | header.pointer_to_raw_data, |
| 532 | | new_offset, |
| 533 | | }); |
| 534 | | const amt = try coff.base.file.?.copyRangeAll( |
| 535 | | header.pointer_to_raw_data, |
| 536 | | coff.base.file.?, |
| 537 | | new_offset, |
| 538 | | current_size, |
| 539 | | ); |
| 540 | | if (amt != current_size) return error.InputOutput; |
| 541 | | header.pointer_to_raw_data = new_offset; |
| 542 | | } |
| 543 | | |
| 544 | | const sect_vm_capacity = coff.allocatedVirtualSize(header.virtual_address); |
| 545 | | if (needed_size > sect_vm_capacity) { |
| 546 | | coff.markRelocsDirtyByAddress(header.virtual_address + header.virtual_size); |
| 547 | | try coff.growSectionVirtualMemory(sect_id, needed_size); |
| 548 | | } |
| 549 | | |
| 550 | | header.virtual_size = @max(header.virtual_size, needed_size); |
| 551 | | header.size_of_raw_data = needed_size; |
| 552 | | } |
| 553 | | |
| 554 | | fn growSectionVirtualMemory(coff: *Coff, sect_id: u32, needed_size: u32) !void { |
| 555 | | const header = &coff.sections.items(.header)[sect_id]; |
| 556 | | const increased_size = padToIdeal(needed_size); |
| 557 | | const old_aligned_end = header.virtual_address + mem.alignForward(u32, header.virtual_size, coff.page_size); |
| 558 | | const new_aligned_end = header.virtual_address + mem.alignForward(u32, increased_size, coff.page_size); |
| 559 | | const diff = new_aligned_end - old_aligned_end; |
| 560 | | log.debug("growing {s} in virtual memory by {x}", .{ coff.getSectionName(header), diff }); |
| 561 | | |
| 562 | | // TODO: enforce order by increasing VM addresses in coff.sections container. |
| 563 | | // This is required by the loader anyhow as far as I can tell. |
| 564 | | for (coff.sections.items(.header)[sect_id + 1 ..], 0..) |*next_header, next_sect_id| { |
| 565 | | const maybe_last_atom_index = coff.sections.items(.last_atom_index)[sect_id + 1 + next_sect_id]; |
| 566 | | next_header.virtual_address += diff; |
| 567 | | |
| 568 | | if (maybe_last_atom_index) |last_atom_index| { |
| 569 | | var atom_index = last_atom_index; |
| 570 | | while (true) { |
| 571 | | const atom = coff.getAtom(atom_index); |
| 572 | | const sym = atom.getSymbolPtr(coff); |
| 573 | | sym.value += diff; |
| 574 | | |
| 575 | | if (atom.prev_index) |prev_index| { |
| 576 | | atom_index = prev_index; |
| 577 | | } else break; |
| 578 | | } |
| 579 | | } |
| 580 | | } |
| 581 | | |
| 582 | | header.virtual_size = increased_size; |
| 583 | | } |
| 584 | | |
| 585 | | fn allocateAtom(coff: *Coff, atom_index: Atom.Index, new_atom_size: u32, alignment: u32) !u32 { |
| 586 | | const tracy = trace(@src()); |
| 587 | | defer tracy.end(); |
| 588 | | |
| 589 | | const atom = coff.getAtom(atom_index); |
| 590 | | const sect_id = @intFromEnum(atom.getSymbol(coff).section_number) - 1; |
| 591 | | const header = &coff.sections.items(.header)[sect_id]; |
| 592 | | const free_list = &coff.sections.items(.free_list)[sect_id]; |
| 593 | | const maybe_last_atom_index = &coff.sections.items(.last_atom_index)[sect_id]; |
| 594 | | const new_atom_ideal_capacity = if (header.isCode()) padToIdeal(new_atom_size) else new_atom_size; |
| 595 | | |
| 596 | | // We use these to indicate our intention to update metadata, placing the new atom, |
| 597 | | // and possibly removing a free list node. |
| 598 | | // It would be simpler to do it inside the for loop below, but that would cause a |
| 599 | | // problem if an error was returned later in the function. So this action |
| 600 | | // is actually carried out at the end of the function, when errors are no longer possible. |
| 601 | | var atom_placement: ?Atom.Index = null; |
| 602 | | var free_list_removal: ?usize = null; |
| 603 | | |
| 604 | | // First we look for an appropriately sized free list node. |
| 605 | | // The list is unordered. We'll just take the first thing that works. |
| 606 | | const vaddr = blk: { |
| 607 | | var i: usize = 0; |
| 608 | | while (i < free_list.items.len) { |
| 609 | | const big_atom_index = free_list.items[i]; |
| 610 | | const big_atom = coff.getAtom(big_atom_index); |
| 611 | | // We now have a pointer to a live atom that has too much capacity. |
| 612 | | // Is it enough that we could fit this new atom? |
| 613 | | const sym = big_atom.getSymbol(coff); |
| 614 | | const capacity = big_atom.capacity(coff); |
| 615 | | const ideal_capacity = if (header.isCode()) padToIdeal(capacity) else capacity; |
| 616 | | const ideal_capacity_end_vaddr = math.add(u32, sym.value, ideal_capacity) catch ideal_capacity; |
| 617 | | const capacity_end_vaddr = sym.value + capacity; |
| 618 | | const new_start_vaddr_unaligned = capacity_end_vaddr - new_atom_ideal_capacity; |
| 619 | | const new_start_vaddr = mem.alignBackward(u32, new_start_vaddr_unaligned, alignment); |
| 620 | | if (new_start_vaddr < ideal_capacity_end_vaddr) { |
| 621 | | // Additional bookkeeping here to notice if this free list node |
| 622 | | // should be deleted because the atom that it points to has grown to take up |
| 623 | | // more of the extra capacity. |
| 624 | | if (!big_atom.freeListEligible(coff)) { |
| 625 | | _ = free_list.swapRemove(i); |
| 626 | | } else { |
| 627 | | i += 1; |
| 628 | | } |
| 629 | | continue; |
| 630 | | } |
| 631 | | // At this point we know that we will place the new atom here. But the |
| 632 | | // remaining question is whether there is still yet enough capacity left |
| 633 | | // over for there to still be a free list node. |
| 634 | | const remaining_capacity = new_start_vaddr - ideal_capacity_end_vaddr; |
| 635 | | const keep_free_list_node = remaining_capacity >= min_text_capacity; |
| 636 | | |
| 637 | | // Set up the metadata to be updated, after errors are no longer possible. |
| 638 | | atom_placement = big_atom_index; |
| 639 | | if (!keep_free_list_node) { |
| 640 | | free_list_removal = i; |
| 641 | | } |
| 642 | | break :blk new_start_vaddr; |
| 643 | | } else if (maybe_last_atom_index.*) |last_index| { |
| 644 | | const last = coff.getAtom(last_index); |
| 645 | | const last_symbol = last.getSymbol(coff); |
| 646 | | const ideal_capacity = if (header.isCode()) padToIdeal(last.size) else last.size; |
| 647 | | const ideal_capacity_end_vaddr = last_symbol.value + ideal_capacity; |
| 648 | | const new_start_vaddr = mem.alignForward(u32, ideal_capacity_end_vaddr, alignment); |
| 649 | | atom_placement = last_index; |
| 650 | | break :blk new_start_vaddr; |
| 651 | | } else { |
| 652 | | break :blk mem.alignForward(u32, header.virtual_address, alignment); |
| 653 | | } |
| 654 | | }; |
| 655 | | |
| 656 | | const expand_section = if (atom_placement) |placement_index| |
| 657 | | coff.getAtom(placement_index).next_index == null |
| 658 | | else |
| 659 | | true; |
| 660 | | if (expand_section) { |
| 661 | | const needed_size: u32 = (vaddr + new_atom_size) - header.virtual_address; |
| 662 | | try coff.growSection(sect_id, needed_size); |
| 663 | | maybe_last_atom_index.* = atom_index; |
| 664 | | } |
| 665 | | coff.getAtomPtr(atom_index).size = new_atom_size; |
| 666 | | |
| 667 | | if (atom.prev_index) |prev_index| { |
| 668 | | const prev = coff.getAtomPtr(prev_index); |
| 669 | | prev.next_index = atom.next_index; |
| 670 | | } |
| 671 | | if (atom.next_index) |next_index| { |
| 672 | | const next = coff.getAtomPtr(next_index); |
| 673 | | next.prev_index = atom.prev_index; |
| 674 | | } |
| 675 | | |
| 676 | | if (atom_placement) |big_atom_index| { |
| 677 | | const big_atom = coff.getAtomPtr(big_atom_index); |
| 678 | | const atom_ptr = coff.getAtomPtr(atom_index); |
| 679 | | atom_ptr.prev_index = big_atom_index; |
| 680 | | atom_ptr.next_index = big_atom.next_index; |
| 681 | | big_atom.next_index = atom_index; |
| 682 | | } else { |
| 683 | | const atom_ptr = coff.getAtomPtr(atom_index); |
| 684 | | atom_ptr.prev_index = null; |
| 685 | | atom_ptr.next_index = null; |
| 686 | | } |
| 687 | | if (free_list_removal) |i| { |
| 688 | | _ = free_list.swapRemove(i); |
| 689 | | } |
| 690 | | |
| 691 | | return vaddr; |
| 692 | | } |
| 693 | | |
| 694 | | pub fn allocateSymbol(coff: *Coff) !u32 { |
| 695 | | const gpa = coff.base.comp.gpa; |
| 696 | | try coff.locals.ensureUnusedCapacity(gpa, 1); |
| 697 | | |
| 698 | | const index = blk: { |
| 699 | | if (coff.locals_free_list.pop()) |index| { |
| 700 | | log.debug(" (reusing symbol index {d})", .{index}); |
| 701 | | break :blk index; |
| 702 | | } else { |
| 703 | | log.debug(" (allocating symbol index {d})", .{coff.locals.items.len}); |
| 704 | | const index = @as(u32, @intCast(coff.locals.items.len)); |
| 705 | | _ = coff.locals.addOneAssumeCapacity(); |
| 706 | | break :blk index; |
| 707 | | } |
| 708 | | }; |
| 709 | | |
| 710 | | coff.locals.items[index] = .{ |
| 711 | | .name = [_]u8{0} ** 8, |
| 712 | | .value = 0, |
| 713 | | .section_number = .UNDEFINED, |
| 714 | | .type = .{ .base_type = .NULL, .complex_type = .NULL }, |
| 715 | | .storage_class = .NULL, |
| 716 | | .number_of_aux_symbols = 0, |
| 717 | | }; |
| 718 | | |
| 719 | | return index; |
| 720 | | } |
| 721 | | |
| 722 | | fn allocateGlobal(coff: *Coff) !u32 { |
| 723 | | const gpa = coff.base.comp.gpa; |
| 724 | | try coff.globals.ensureUnusedCapacity(gpa, 1); |
| 725 | | |
| 726 | | const index = blk: { |
| 727 | | if (coff.globals_free_list.pop()) |index| { |
| 728 | | log.debug(" (reusing global index {d})", .{index}); |
| 729 | | break :blk index; |
| 730 | | } else { |
| 731 | | log.debug(" (allocating global index {d})", .{coff.globals.items.len}); |
| 732 | | const index = @as(u32, @intCast(coff.globals.items.len)); |
| 733 | | _ = coff.globals.addOneAssumeCapacity(); |
| 734 | | break :blk index; |
| 735 | | } |
| 736 | | }; |
| 737 | | |
| 738 | | coff.globals.items[index] = .{ |
| 739 | | .sym_index = 0, |
| 740 | | .file = null, |
| 741 | | }; |
| 742 | | |
| 743 | | return index; |
| 744 | | } |
| 745 | | |
| 746 | | fn addGotEntry(coff: *Coff, target: SymbolWithLoc) !void { |
| 747 | | const gpa = coff.base.comp.gpa; |
| 748 | | if (coff.got_table.lookup.contains(target)) return; |
| 749 | | const got_index = try coff.got_table.allocateEntry(gpa, target); |
| 750 | | try coff.writeOffsetTableEntry(got_index); |
| 751 | | coff.got_table_count_dirty = true; |
| 752 | | coff.markRelocsDirtyByTarget(target); |
| 753 | | } |
| 754 | | |
| 755 | | pub fn createAtom(coff: *Coff) !Atom.Index { |
| 756 | | const gpa = coff.base.comp.gpa; |
| 757 | | const atom_index = @as(Atom.Index, @intCast(coff.atoms.items.len)); |
| 758 | | const atom = try coff.atoms.addOne(gpa); |
| 759 | | const sym_index = try coff.allocateSymbol(); |
| 760 | | try coff.atom_by_index_table.putNoClobber(gpa, sym_index, atom_index); |
| 761 | | atom.* = .{ |
| 762 | | .sym_index = sym_index, |
| 763 | | .file = null, |
| 764 | | .size = 0, |
| 765 | | .prev_index = null, |
| 766 | | .next_index = null, |
| 767 | | }; |
| 768 | | log.debug("creating ATOM(%{d}) at index {d}", .{ sym_index, atom_index }); |
| 769 | | return atom_index; |
| 770 | | } |
| 771 | | |
| 772 | | fn growAtom(coff: *Coff, atom_index: Atom.Index, new_atom_size: u32, alignment: u32) !u32 { |
| 773 | | const atom = coff.getAtom(atom_index); |
| 774 | | const sym = atom.getSymbol(coff); |
| 775 | | const align_ok = mem.alignBackward(u32, sym.value, alignment) == sym.value; |
| 776 | | const need_realloc = !align_ok or new_atom_size > atom.capacity(coff); |
| 777 | | if (!need_realloc) return sym.value; |
| 778 | | return coff.allocateAtom(atom_index, new_atom_size, alignment); |
| 779 | | } |
| 780 | | |
| 781 | | fn shrinkAtom(coff: *Coff, atom_index: Atom.Index, new_block_size: u32) void { |
| 782 | | _ = coff; |
| 783 | | _ = atom_index; |
| 784 | | _ = new_block_size; |
| 785 | | // TODO check the new capacity, and if it crosses the size threshold into a big enough |
| 786 | | // capacity, insert a free list node for it. |
| 787 | | } |
| 788 | | |
| 789 | | fn writeAtom(coff: *Coff, atom_index: Atom.Index, code: []u8, resolve_relocs: bool) !void { |
| 790 | | const atom = coff.getAtom(atom_index); |
| 791 | | const sym = atom.getSymbol(coff); |
| 792 | | const section = coff.sections.get(@intFromEnum(sym.section_number) - 1); |
| 793 | | const file_offset = section.header.pointer_to_raw_data + sym.value - section.header.virtual_address; |
| 794 | | |
| 795 | | log.debug("writing atom for symbol {s} at file offset 0x{x} to 0x{x}", .{ |
| 796 | | atom.getName(coff), |
| 797 | | file_offset, |
| 798 | | file_offset + code.len, |
| 799 | | }); |
| 800 | | |
| 801 | | const gpa = coff.base.comp.gpa; |
| 802 | | |
| 803 | | // Gather relocs which can be resolved. |
| 804 | | // We need to do this as we will be applying different slide values depending |
| 805 | | // if we are running in hot-code swapping mode or not. |
| 806 | | // TODO: how crazy would it be to try and apply the actual image base of the loaded |
| 807 | | // process for the in-file values rather than the Windows defaults? |
| 808 | | var relocs = std.array_list.Managed(*Relocation).init(gpa); |
| 809 | | defer relocs.deinit(); |
| 810 | | |
| 811 | | if (resolve_relocs) { |
| 812 | | if (coff.relocs.getPtr(atom_index)) |rels| { |
| 813 | | try relocs.ensureTotalCapacityPrecise(rels.items.len); |
| 814 | | for (rels.items) |*reloc| { |
| 815 | | if (reloc.isResolvable(coff) and reloc.dirty) { |
| 816 | | relocs.appendAssumeCapacity(reloc); |
| 817 | | } |
| 818 | | } |
| 819 | | } |
| 820 | | } |
| 821 | | |
| 822 | | if (is_hot_update_compatible) { |
| 823 | | if (coff.base.child_pid) |handle| { |
| 824 | | const slide = @intFromPtr(coff.hot_state.loaded_base_address.?); |
| 825 | | |
| 826 | | const mem_code = try gpa.dupe(u8, code); |
| 827 | | defer gpa.free(mem_code); |
| 828 | | coff.resolveRelocs(atom_index, relocs.items, mem_code, slide); |
| 829 | | |
| 830 | | const vaddr = sym.value + slide; |
| 831 | | const pvaddr = @as(*anyopaque, @ptrFromInt(vaddr)); |
| 832 | | |
| 833 | | log.debug("writing to memory at address {x}", .{vaddr}); |
| 834 | | |
| 835 | | if (build_options.enable_logging) { |
| 836 | | try debugMem(gpa, handle, pvaddr, mem_code); |
| 837 | | } |
| 838 | | |
| 839 | | if (!section.header.flags.MEM_WRITE) { |
| 840 | | writeMemProtected(handle, pvaddr, mem_code) catch |err| { |
| 841 | | log.warn("writing to protected memory failed with error: {s}", .{@errorName(err)}); |
| 842 | | }; |
| 843 | | } else { |
| 844 | | writeMem(handle, pvaddr, mem_code) catch |err| { |
| 845 | | log.warn("writing to protected memory failed with error: {s}", .{@errorName(err)}); |
| 846 | | }; |
| 847 | | } |
| 848 | | } |
| 849 | | } |
| 850 | | |
| 851 | | if (resolve_relocs) { |
| 852 | | coff.resolveRelocs(atom_index, relocs.items, code, coff.image_base); |
| 853 | | } |
| 854 | | try coff.pwriteAll(code, file_offset); |
| 855 | | if (resolve_relocs) { |
| 856 | | // Now we can mark the relocs as resolved. |
| 857 | | while (relocs.pop()) |reloc| { |
| 858 | | reloc.dirty = false; |
| 859 | | } |
| 860 | | } |
| 861 | | } |
| 862 | | |
| 863 | | fn debugMem(allocator: Allocator, handle: std.process.Child.Id, pvaddr: std.os.windows.LPVOID, code: []const u8) !void { |
| 864 | | const buffer = try allocator.alloc(u8, code.len); |
| 865 | | defer allocator.free(buffer); |
| 866 | | const memread = try std.os.windows.ReadProcessMemory(handle, pvaddr, buffer); |
| 867 | | log.debug("to write: {x}", .{code}); |
| 868 | | log.debug("in memory: {x}", .{memread}); |
| 869 | | } |
| 870 | | |
| 871 | | fn writeMemProtected(handle: std.process.Child.Id, pvaddr: std.os.windows.LPVOID, code: []const u8) !void { |
| 872 | | const old_prot = try std.os.windows.VirtualProtectEx(handle, pvaddr, code.len, std.os.windows.PAGE_EXECUTE_WRITECOPY); |
| 873 | | try writeMem(handle, pvaddr, code); |
| 874 | | // TODO: We can probably just set the pages writeable and leave it at that without having to restore the attributes. |
| 875 | | // For that though, we want to track which page has already been modified. |
| 876 | | _ = try std.os.windows.VirtualProtectEx(handle, pvaddr, code.len, old_prot); |
| 877 | | } |
| 878 | | |
| 879 | | fn writeMem(handle: std.process.Child.Id, pvaddr: std.os.windows.LPVOID, code: []const u8) !void { |
| 880 | | const amt = try std.os.windows.WriteProcessMemory(handle, pvaddr, code); |
| 881 | | if (amt != code.len) return error.InputOutput; |
| 882 | | } |
| 883 | | |
| 884 | | fn writeOffsetTableEntry(coff: *Coff, index: usize) !void { |
| 885 | | const sect_id = coff.got_section_index.?; |
| 886 | | |
| 887 | | if (coff.got_table_count_dirty) { |
| 888 | | const needed_size: u32 = @intCast(coff.got_table.entries.items.len * coff.ptr_width.size()); |
| 889 | | try coff.growSection(sect_id, needed_size); |
| 890 | | coff.got_table_count_dirty = false; |
| 891 | | } |
| 892 | | |
| 893 | | const header = &coff.sections.items(.header)[sect_id]; |
| 894 | | const entry = coff.got_table.entries.items[index]; |
| 895 | | const entry_value = coff.getSymbol(entry).value; |
| 896 | | const entry_offset = index * coff.ptr_width.size(); |
| 897 | | const file_offset = header.pointer_to_raw_data + entry_offset; |
| 898 | | const vmaddr = header.virtual_address + entry_offset; |
| 899 | | |
| 900 | | log.debug("writing GOT entry {d}: @{x} => {x}", .{ index, vmaddr, entry_value + coff.image_base }); |
| 901 | | |
| 902 | | switch (coff.ptr_width) { |
| 903 | | .p32 => { |
| 904 | | var buf: [4]u8 = undefined; |
| 905 | | mem.writeInt(u32, &buf, @intCast(entry_value + coff.image_base), .little); |
| 906 | | try coff.base.file.?.pwriteAll(&buf, file_offset); |
| 907 | | }, |
| 908 | | .p64 => { |
| 909 | | var buf: [8]u8 = undefined; |
| 910 | | mem.writeInt(u64, &buf, entry_value + coff.image_base, .little); |
| 911 | | try coff.base.file.?.pwriteAll(&buf, file_offset); |
| 912 | | }, |
| 913 | | } |
| 914 | | |
| 915 | | if (is_hot_update_compatible) { |
| 916 | | if (coff.base.child_pid) |handle| { |
| 917 | | const gpa = coff.base.comp.gpa; |
| 918 | | const slide = @intFromPtr(coff.hot_state.loaded_base_address.?); |
| 919 | | const actual_vmaddr = vmaddr + slide; |
| 920 | | const pvaddr = @as(*anyopaque, @ptrFromInt(actual_vmaddr)); |
| 921 | | log.debug("writing GOT entry to memory at address {x}", .{actual_vmaddr}); |
| 922 | | if (build_options.enable_logging) { |
| 923 | | switch (coff.ptr_width) { |
| 924 | | .p32 => { |
| 925 | | var buf: [4]u8 = undefined; |
| 926 | | try debugMem(gpa, handle, pvaddr, &buf); |
| 927 | | }, |
| 928 | | .p64 => { |
| 929 | | var buf: [8]u8 = undefined; |
| 930 | | try debugMem(gpa, handle, pvaddr, &buf); |
| 931 | | }, |
| 932 | | } |
| 933 | | } |
| 934 | | |
| 935 | | switch (coff.ptr_width) { |
| 936 | | .p32 => { |
| 937 | | var buf: [4]u8 = undefined; |
| 938 | | mem.writeInt(u32, &buf, @as(u32, @intCast(entry_value + slide)), .little); |
| 939 | | writeMem(handle, pvaddr, &buf) catch |err| { |
| 940 | | log.warn("writing to protected memory failed with error: {s}", .{@errorName(err)}); |
| 941 | | }; |
| 942 | | }, |
| 943 | | .p64 => { |
| 944 | | var buf: [8]u8 = undefined; |
| 945 | | mem.writeInt(u64, &buf, entry_value + slide, .little); |
| 946 | | writeMem(handle, pvaddr, &buf) catch |err| { |
| 947 | | log.warn("writing to protected memory failed with error: {s}", .{@errorName(err)}); |
| 948 | | }; |
| 949 | | }, |
| 950 | | } |
| 951 | | } |
| 952 | | } |
| 953 | | } |
| 954 | | |
| 955 | | fn markRelocsDirtyByTarget(coff: *Coff, target: SymbolWithLoc) void { |
| 956 | | if (!coff.base.comp.config.incremental) return; |
| 957 | | // TODO: reverse-lookup might come in handy here |
| 958 | | for (coff.relocs.values()) |*relocs| { |
| 959 | | for (relocs.items) |*reloc| { |
| 960 | | if (!reloc.target.eql(target)) continue; |
| 961 | | reloc.dirty = true; |
| 962 | | } |
| 963 | | } |
| 964 | | } |
| 965 | | |
| 966 | | fn markRelocsDirtyByAddress(coff: *Coff, addr: u32) void { |
| 967 | | if (!coff.base.comp.config.incremental) return; |
| 968 | | const got_moved = blk: { |
| 969 | | const sect_id = coff.got_section_index orelse break :blk false; |
| 970 | | break :blk coff.sections.items(.header)[sect_id].virtual_address >= addr; |
| 971 | | }; |
| 972 | | |
| 973 | | // TODO: dirty relocations targeting import table if that got moved in memory |
| 974 | | |
| 975 | | for (coff.relocs.values()) |*relocs| { |
| 976 | | for (relocs.items) |*reloc| { |
| 977 | | if (reloc.isGotIndirection()) { |
| 978 | | reloc.dirty = reloc.dirty or got_moved; |
| 979 | | } else { |
| 980 | | const target_vaddr = reloc.getTargetAddress(coff) orelse continue; |
| 981 | | if (target_vaddr >= addr) reloc.dirty = true; |
| 982 | | } |
| 983 | | } |
| 984 | | } |
| 985 | | |
| 986 | | // TODO: dirty only really affected GOT cells |
| 987 | | for (coff.got_table.entries.items) |entry| { |
| 988 | | const target_addr = coff.getSymbol(entry).value; |
| 989 | | if (target_addr >= addr) { |
| 990 | | coff.got_table_contents_dirty = true; |
| 991 | | break; |
| 992 | | } |
| 993 | | } |
| 994 | | } |
| 995 | | |
| 996 | | fn resolveRelocs(coff: *Coff, atom_index: Atom.Index, relocs: []const *const Relocation, code: []u8, image_base: u64) void { |
| 997 | | log.debug("relocating '{s}'", .{coff.getAtom(atom_index).getName(coff)}); |
| 998 | | for (relocs) |reloc| { |
| 999 | | reloc.resolve(atom_index, code, image_base, coff); |
| 1000 | | } |
| 1001 | | } |
| 1002 | | |
| 1003 | | pub fn ptraceAttach(coff: *Coff, handle: std.process.Child.Id) !void { |
| 1004 | | if (!is_hot_update_compatible) return; |
| 1005 | | |
| 1006 | | log.debug("attaching to process with handle {*}", .{handle}); |
| 1007 | | coff.hot_state.loaded_base_address = std.os.windows.ProcessBaseAddress(handle) catch |err| { |
| 1008 | | log.warn("failed to get base address for the process with error: {s}", .{@errorName(err)}); |
| 1009 | | return; |
| 1010 | | }; |
| 1011 | | } |
| 1012 | | |
| 1013 | | pub fn ptraceDetach(coff: *Coff, handle: std.process.Child.Id) void { |
| 1014 | | if (!is_hot_update_compatible) return; |
| 1015 | | |
| 1016 | | log.debug("detaching from process with handle {*}", .{handle}); |
| 1017 | | coff.hot_state.loaded_base_address = null; |
| 1018 | | } |
| 1019 | | |
| 1020 | | fn freeAtom(coff: *Coff, atom_index: Atom.Index) void { |
| 1021 | | log.debug("freeAtom {d}", .{atom_index}); |
| 1022 | | |
| 1023 | | const gpa = coff.base.comp.gpa; |
| 1024 | | |
| 1025 | | // Remove any relocs and base relocs associated with this Atom |
| 1026 | | coff.freeRelocations(atom_index); |
| 1027 | | |
| 1028 | | const atom = coff.getAtom(atom_index); |
| 1029 | | const sym = atom.getSymbol(coff); |
| 1030 | | const sect_id = @intFromEnum(sym.section_number) - 1; |
| 1031 | | const free_list = &coff.sections.items(.free_list)[sect_id]; |
| 1032 | | var already_have_free_list_node = false; |
| 1033 | | { |
| 1034 | | var i: usize = 0; |
| 1035 | | // TODO turn free_list into a hash map |
| 1036 | | while (i < free_list.items.len) { |
| 1037 | | if (free_list.items[i] == atom_index) { |
| 1038 | | _ = free_list.swapRemove(i); |
| 1039 | | continue; |
| 1040 | | } |
| 1041 | | if (free_list.items[i] == atom.prev_index) { |
| 1042 | | already_have_free_list_node = true; |
| 1043 | | } |
| 1044 | | i += 1; |
| 1045 | | } |
| 1046 | | } |
| 1047 | | |
| 1048 | | const maybe_last_atom_index = &coff.sections.items(.last_atom_index)[sect_id]; |
| 1049 | | if (maybe_last_atom_index.*) |last_atom_index| { |
| 1050 | | if (last_atom_index == atom_index) { |
| 1051 | | if (atom.prev_index) |prev_index| { |
| 1052 | | // TODO shrink the section size here |
| 1053 | | maybe_last_atom_index.* = prev_index; |
| 1054 | | } else { |
| 1055 | | maybe_last_atom_index.* = null; |
| 1056 | | } |
| 1057 | | } |
| 1058 | | } |
| 1059 | | |
| 1060 | | if (atom.prev_index) |prev_index| { |
| 1061 | | const prev = coff.getAtomPtr(prev_index); |
| 1062 | | prev.next_index = atom.next_index; |
| 1063 | | |
| 1064 | | if (!already_have_free_list_node and prev.*.freeListEligible(coff)) { |
| 1065 | | // The free list is heuristics, it doesn't have to be perfect, so we can |
| 1066 | | // ignore the OOM here. |
| 1067 | | free_list.append(gpa, prev_index) catch {}; |
| 1068 | | } |
| 1069 | | } else { |
| 1070 | | coff.getAtomPtr(atom_index).prev_index = null; |
| 1071 | | } |
| 1072 | | |
| 1073 | | if (atom.next_index) |next_index| { |
| 1074 | | coff.getAtomPtr(next_index).prev_index = atom.prev_index; |
| 1075 | | } else { |
| 1076 | | coff.getAtomPtr(atom_index).next_index = null; |
| 1077 | | } |
| 1078 | | |
| 1079 | | // Appending to free lists is allowed to fail because the free lists are heuristics based anyway. |
| 1080 | | const sym_index = atom.getSymbolIndex().?; |
| 1081 | | coff.locals_free_list.append(gpa, sym_index) catch {}; |
| 1082 | | |
| 1083 | | // Try freeing GOT atom if this decl had one |
| 1084 | | coff.got_table.freeEntry(gpa, .{ .sym_index = sym_index }); |
| 1085 | | |
| 1086 | | coff.locals.items[sym_index].section_number = .UNDEFINED; |
| 1087 | | _ = coff.atom_by_index_table.remove(sym_index); |
| 1088 | | log.debug(" adding local symbol index {d} to free list", .{sym_index}); |
| 1089 | | coff.getAtomPtr(atom_index).sym_index = 0; |
| 1090 | | } |
| 1091 | | |
| 1092 | | pub fn updateFunc( |
| 1093 | | coff: *Coff, |
| 1094 | | pt: Zcu.PerThread, |
| 1095 | | func_index: InternPool.Index, |
| 1096 | | mir: *const codegen.AnyMir, |
| 1097 | | ) link.File.UpdateNavError!void { |
| 1098 | | if (build_options.skip_non_native and builtin.object_format != .coff) { |
| 1099 | | @panic("Attempted to compile for object format that was disabled by build configuration"); |
| 1100 | | } |
| 1101 | | const tracy = trace(@src()); |
| 1102 | | defer tracy.end(); |
| 1103 | | |
| 1104 | | const zcu = pt.zcu; |
| 1105 | | const gpa = zcu.gpa; |
| 1106 | | const func = zcu.funcInfo(func_index); |
| 1107 | | const nav_index = func.owner_nav; |
| 1108 | | |
| 1109 | | const atom_index = try coff.getOrCreateAtomForNav(nav_index); |
| 1110 | | coff.freeRelocations(atom_index); |
| 1111 | | |
| 1112 | | coff.navs.getPtr(func.owner_nav).?.section = coff.text_section_index.?; |
| 1113 | | |
| 1114 | | var aw: std.Io.Writer.Allocating = .init(gpa); |
| 1115 | | defer aw.deinit(); |
| 1116 | | |
| 1117 | | codegen.emitFunction( |
| 1118 | | &coff.base, |
| 1119 | | pt, |
| 1120 | | zcu.navSrcLoc(nav_index), |
| 1121 | | func_index, |
| 1122 | | coff.getAtom(atom_index).getSymbolIndex().?, |
| 1123 | | mir, |
| 1124 | | &aw.writer, |
| 1125 | | .none, |
| 1126 | | ) catch |err| switch (err) { |
| 1127 | | error.WriteFailed => return error.OutOfMemory, |
| 1128 | | else => |e| return e, |
| 1129 | | }; |
| 1130 | | |
| 1131 | | try coff.updateNavCode(pt, nav_index, aw.written(), .FUNCTION); |
| 1132 | | |
| 1133 | | // Exports will be updated by `Zcu.processExports` after the update. |
| 1134 | | } |
| 1135 | | |
| 1136 | | const LowerConstResult = union(enum) { |
| 1137 | | ok: Atom.Index, |
| 1138 | | fail: *Zcu.ErrorMsg, |
| 1139 | | }; |
| 1140 | | |
| 1141 | | fn lowerConst( |
| 1142 | | coff: *Coff, |
| 1143 | | pt: Zcu.PerThread, |
| 1144 | | name: []const u8, |
| 1145 | | val: Value, |
| 1146 | | required_alignment: InternPool.Alignment, |
| 1147 | | sect_id: u16, |
| 1148 | | src_loc: Zcu.LazySrcLoc, |
| 1149 | | ) !LowerConstResult { |
| 1150 | | const gpa = coff.base.comp.gpa; |
| 1151 | | |
| 1152 | | var aw: std.Io.Writer.Allocating = .init(gpa); |
| 1153 | | defer aw.deinit(); |
| 1154 | | |
| 1155 | | const atom_index = try coff.createAtom(); |
| 1156 | | const sym = coff.getAtom(atom_index).getSymbolPtr(coff); |
| 1157 | | try coff.setSymbolName(sym, name); |
| 1158 | | sym.section_number = @as(coff_util.SectionNumber, @enumFromInt(sect_id + 1)); |
| 1159 | | |
| 1160 | | try codegen.generateSymbol(&coff.base, pt, src_loc, val, &aw.writer, .{ |
| 1161 | | .atom_index = coff.getAtom(atom_index).getSymbolIndex().?, |
| 1162 | | }); |
| 1163 | | const code = aw.written(); |
| 1164 | | |
| 1165 | | const atom = coff.getAtomPtr(atom_index); |
| 1166 | | atom.size = @intCast(code.len); |
| 1167 | | atom.getSymbolPtr(coff).value = try coff.allocateAtom( |
| 1168 | | atom_index, |
| 1169 | | atom.size, |
| 1170 | | @intCast(required_alignment.toByteUnits().?), |
| 1171 | | ); |
| 1172 | | errdefer coff.freeAtom(atom_index); |
| 1173 | | |
| 1174 | | log.debug("allocated atom for {s} at 0x{x}", .{ name, atom.getSymbol(coff).value }); |
| 1175 | | log.debug(" (required alignment 0x{x})", .{required_alignment}); |
| 1176 | | |
| 1177 | | try coff.writeAtom(atom_index, code, coff.base.comp.config.incremental); |
| 1178 | | |
| 1179 | | return .{ .ok = atom_index }; |
| 1180 | | } |
| 1181 | | |
| 1182 | | pub fn updateNav( |
| 1183 | | coff: *Coff, |
| 1184 | | pt: Zcu.PerThread, |
| 1185 | | nav_index: InternPool.Nav.Index, |
| 1186 | | ) link.File.UpdateNavError!void { |
| 1187 | | if (build_options.skip_non_native and builtin.object_format != .coff) { |
| 1188 | | @panic("Attempted to compile for object format that was disabled by build configuration"); |
| 1189 | | } |
| 1190 | | const tracy = trace(@src()); |
| 1191 | | defer tracy.end(); |
| 1192 | | |
| 1193 | | const zcu = pt.zcu; |
| 1194 | | const gpa = zcu.gpa; |
| 1195 | | const ip = &zcu.intern_pool; |
| 1196 | | const nav = ip.getNav(nav_index); |
| 1197 | | |
| 1198 | | const nav_val = zcu.navValue(nav_index); |
| 1199 | | const nav_init = switch (ip.indexToKey(nav_val.toIntern())) { |
| 1200 | | .func => return, |
| 1201 | | .variable => |variable| Value.fromInterned(variable.init), |
| 1202 | | .@"extern" => |@"extern"| { |
| 1203 | | if (ip.isFunctionType(@"extern".ty)) return; |
| 1204 | | // TODO make this part of getGlobalSymbol |
| 1205 | | const name = nav.name.toSlice(ip); |
| 1206 | | const lib_name = @"extern".lib_name.toSlice(ip); |
| 1207 | | const global_index = try coff.getGlobalSymbol(name, lib_name); |
| 1208 | | try coff.need_got_table.put(gpa, global_index, {}); |
| 1209 | | return; |
| 1210 | | }, |
| 1211 | | else => nav_val, |
| 1212 | | }; |
| 1213 | | |
| 1214 | | if (nav_init.typeOf(zcu).hasRuntimeBits(zcu)) { |
| 1215 | | const atom_index = try coff.getOrCreateAtomForNav(nav_index); |
| 1216 | | coff.freeRelocations(atom_index); |
| 1217 | | const atom = coff.getAtom(atom_index); |
| 1218 | | |
| 1219 | | coff.navs.getPtr(nav_index).?.section = coff.getNavOutputSection(nav_index); |
| 1220 | | |
| 1221 | | var aw: std.Io.Writer.Allocating = .init(gpa); |
| 1222 | | defer aw.deinit(); |
| 1223 | | |
| 1224 | | codegen.generateSymbol( |
| 1225 | | &coff.base, |
| 1226 | | pt, |
| 1227 | | zcu.navSrcLoc(nav_index), |
| 1228 | | nav_init, |
| 1229 | | &aw.writer, |
| 1230 | | .{ .atom_index = atom.getSymbolIndex().? }, |
| 1231 | | ) catch |err| switch (err) { |
| 1232 | | error.WriteFailed => return error.OutOfMemory, |
| 1233 | | else => |e| return e, |
| 1234 | | }; |
| 1235 | | |
| 1236 | | try coff.updateNavCode(pt, nav_index, aw.written(), .NULL); |
| 1237 | | } |
| 1238 | | |
| 1239 | | // Exports will be updated by `Zcu.processExports` after the update. |
| 1240 | | } |
| 1241 | | |
| 1242 | | fn updateLazySymbolAtom( |
| 1243 | | coff: *Coff, |
| 1244 | | pt: Zcu.PerThread, |
| 1245 | | sym: link.File.LazySymbol, |
| 1246 | | atom_index: Atom.Index, |
| 1247 | | section_index: u16, |
| 1248 | | ) !void { |
| 1249 | | const zcu = pt.zcu; |
| 1250 | | const comp = coff.base.comp; |
| 1251 | | const gpa = comp.gpa; |
| 1252 | | |
| 1253 | | var required_alignment: InternPool.Alignment = .none; |
| 1254 | | var aw: std.Io.Writer.Allocating = .init(gpa); |
| 1255 | | defer aw.deinit(); |
| 1256 | | |
| 1257 | | const name = try allocPrint(gpa, "__lazy_{s}_{f}", .{ |
| 1258 | | @tagName(sym.kind), |
| 1259 | | Type.fromInterned(sym.ty).fmt(pt), |
| 1260 | | }); |
| 1261 | | defer gpa.free(name); |
| 1262 | | |
| 1263 | | const local_sym_index = coff.getAtomPtr(atom_index).getSymbolIndex().?; |
| 1264 | | |
| 1265 | | const src = Type.fromInterned(sym.ty).srcLocOrNull(zcu) orelse Zcu.LazySrcLoc.unneeded; |
| 1266 | | try codegen.generateLazySymbol( |
| 1267 | | &coff.base, |
| 1268 | | pt, |
| 1269 | | src, |
| 1270 | | sym, |
| 1271 | | &required_alignment, |
| 1272 | | &aw.writer, |
| 1273 | | .none, |
| 1274 | | .{ .atom_index = local_sym_index }, |
| 1275 | | ); |
| 1276 | | const code = aw.written(); |
| 1277 | | |
| 1278 | | const atom = coff.getAtomPtr(atom_index); |
| 1279 | | const symbol = atom.getSymbolPtr(coff); |
| 1280 | | try coff.setSymbolName(symbol, name); |
| 1281 | | symbol.section_number = @enumFromInt(section_index + 1); |
| 1282 | | symbol.type = .{ .complex_type = .NULL, .base_type = .NULL }; |
| 1283 | | |
| 1284 | | const code_len: u32 = @intCast(code.len); |
| 1285 | | const vaddr = try coff.allocateAtom(atom_index, code_len, @intCast(required_alignment.toByteUnits() orelse 0)); |
| 1286 | | errdefer coff.freeAtom(atom_index); |
| 1287 | | |
| 1288 | | log.debug("allocated atom for {s} at 0x{x}", .{ name, vaddr }); |
| 1289 | | log.debug(" (required alignment 0x{x})", .{required_alignment}); |
| 1290 | | |
| 1291 | | atom.size = code_len; |
| 1292 | | symbol.value = vaddr; |
| 1293 | | |
| 1294 | | try coff.addGotEntry(.{ .sym_index = local_sym_index }); |
| 1295 | | try coff.writeAtom(atom_index, code, coff.base.comp.config.incremental); |
| 1296 | | } |
| 1297 | | |
| 1298 | | pub fn getOrCreateAtomForLazySymbol( |
| 1299 | | coff: *Coff, |
| 1300 | | pt: Zcu.PerThread, |
| 1301 | | lazy_sym: link.File.LazySymbol, |
| 1302 | | ) !Atom.Index { |
| 1303 | | const gop = try coff.lazy_syms.getOrPut(pt.zcu.gpa, lazy_sym.ty); |
| 1304 | | errdefer _ = if (!gop.found_existing) coff.lazy_syms.pop(); |
| 1305 | | if (!gop.found_existing) gop.value_ptr.* = .{}; |
| 1306 | | const atom_ptr, const state_ptr = switch (lazy_sym.kind) { |
| 1307 | | .code => .{ &gop.value_ptr.text_atom, &gop.value_ptr.text_state }, |
| 1308 | | .const_data => .{ &gop.value_ptr.rdata_atom, &gop.value_ptr.rdata_state }, |
| 1309 | | }; |
| 1310 | | switch (state_ptr.*) { |
| 1311 | | .unused => atom_ptr.* = try coff.createAtom(), |
| 1312 | | .pending_flush => return atom_ptr.*, |
| 1313 | | .flushed => {}, |
| 1314 | | } |
| 1315 | | state_ptr.* = .pending_flush; |
| 1316 | | const atom = atom_ptr.*; |
| 1317 | | // anyerror needs to be deferred until flush |
| 1318 | | if (lazy_sym.ty != .anyerror_type) try coff.updateLazySymbolAtom(pt, lazy_sym, atom, switch (lazy_sym.kind) { |
| 1319 | | .code => coff.text_section_index.?, |
| 1320 | | .const_data => coff.rdata_section_index.?, |
| 1321 | | }); |
| 1322 | | return atom; |
| 1323 | | } |
| 1324 | | |
| 1325 | | pub fn getOrCreateAtomForNav(coff: *Coff, nav_index: InternPool.Nav.Index) !Atom.Index { |
| 1326 | | const gpa = coff.base.comp.gpa; |
| 1327 | | const gop = try coff.navs.getOrPut(gpa, nav_index); |
| 1328 | | if (!gop.found_existing) { |
| 1329 | | gop.value_ptr.* = .{ |
| 1330 | | .atom = try coff.createAtom(), |
| 1331 | | // If necessary, this will be modified by `updateNav` or `updateFunc`. |
| 1332 | | .section = coff.rdata_section_index.?, |
| 1333 | | .exports = .{}, |
| 1334 | | }; |
| 1335 | | } |
| 1336 | | return gop.value_ptr.atom; |
| 1337 | | } |
| 1338 | | |
| 1339 | | fn getNavOutputSection(coff: *Coff, nav_index: InternPool.Nav.Index) u16 { |
| 1340 | | const zcu = coff.base.comp.zcu.?; |
| 1341 | | const ip = &zcu.intern_pool; |
| 1342 | | const nav = ip.getNav(nav_index); |
| 1343 | | const ty = Type.fromInterned(nav.typeOf(ip)); |
| 1344 | | const zig_ty = ty.zigTypeTag(zcu); |
| 1345 | | const val = Value.fromInterned(nav.status.fully_resolved.val); |
| 1346 | | const index: u16 = blk: { |
| 1347 | | if (val.isUndef(zcu)) { |
| 1348 | | // TODO in release-fast and release-small, we should put undef in .bss |
| 1349 | | break :blk coff.data_section_index.?; |
| 1350 | | } |
| 1351 | | |
| 1352 | | switch (zig_ty) { |
| 1353 | | // TODO: what if this is a function pointer? |
| 1354 | | .@"fn" => break :blk coff.text_section_index.?, |
| 1355 | | else => { |
| 1356 | | if (val.getVariable(zcu)) |_| { |
| 1357 | | break :blk coff.data_section_index.?; |
| 1358 | | } |
| 1359 | | break :blk coff.rdata_section_index.?; |
| 1360 | | }, |
| 1361 | | } |
| 1362 | | }; |
| 1363 | | return index; |
| 1364 | | } |
| 1365 | | |
| 1366 | | fn updateNavCode( |
| 1367 | | coff: *Coff, |
| 1368 | | pt: Zcu.PerThread, |
| 1369 | | nav_index: InternPool.Nav.Index, |
| 1370 | | code: []u8, |
| 1371 | | complex_type: coff_util.ComplexType, |
| 1372 | | ) link.File.UpdateNavError!void { |
| 1373 | | const zcu = pt.zcu; |
| 1374 | | const ip = &zcu.intern_pool; |
| 1375 | | const nav = ip.getNav(nav_index); |
| 1376 | | |
| 1377 | | log.debug("updateNavCode {f} 0x{x}", .{ nav.fqn.fmt(ip), nav_index }); |
| 1378 | | |
| 1379 | | const mod = zcu.navFileScope(nav_index).mod.?; |
| 1380 | | const target = &mod.resolved_target.result; |
| 1381 | | const required_alignment = switch (nav.status.fully_resolved.alignment) { |
| 1382 | | .none => switch (mod.optimize_mode) { |
| 1383 | | .Debug, .ReleaseSafe, .ReleaseFast => target_util.defaultFunctionAlignment(target), |
| 1384 | | .ReleaseSmall => target_util.minFunctionAlignment(target), |
| 1385 | | }, |
| 1386 | | else => |a| a.maxStrict(target_util.minFunctionAlignment(target)), |
| 1387 | | }; |
| 1388 | | |
| 1389 | | const nav_metadata = coff.navs.get(nav_index).?; |
| 1390 | | const atom_index = nav_metadata.atom; |
| 1391 | | const atom = coff.getAtom(atom_index); |
| 1392 | | const sym_index = atom.getSymbolIndex().?; |
| 1393 | | const sect_index = nav_metadata.section; |
| 1394 | | const code_len: u32 = @intCast(code.len); |
| 1395 | | |
| 1396 | | if (atom.size != 0) { |
| 1397 | | const sym = atom.getSymbolPtr(coff); |
| 1398 | | try coff.setSymbolName(sym, nav.fqn.toSlice(ip)); |
| 1399 | | sym.section_number = @enumFromInt(sect_index + 1); |
| 1400 | | sym.type = .{ .complex_type = complex_type, .base_type = .NULL }; |
| 1401 | | |
| 1402 | | const capacity = atom.capacity(coff); |
| 1403 | | const need_realloc = code.len > capacity or !required_alignment.check(sym.value); |
| 1404 | | if (need_realloc) { |
| 1405 | | const vaddr = coff.growAtom(atom_index, code_len, @intCast(required_alignment.toByteUnits() orelse 0)) catch |err| switch (err) { |
| 1406 | | error.OutOfMemory => return error.OutOfMemory, |
| 1407 | | else => |e| return coff.base.cgFail(nav_index, "failed to grow atom: {s}", .{@errorName(e)}), |
| 1408 | | }; |
| 1409 | | log.debug("growing {f} from 0x{x} to 0x{x}", .{ nav.fqn.fmt(ip), sym.value, vaddr }); |
| 1410 | | log.debug(" (required alignment 0x{x}", .{required_alignment}); |
| 1411 | | |
| 1412 | | if (vaddr != sym.value) { |
| 1413 | | sym.value = vaddr; |
| 1414 | | log.debug(" (updating GOT entry)", .{}); |
| 1415 | | const got_entry_index = coff.got_table.lookup.get(.{ .sym_index = sym_index }).?; |
| 1416 | | coff.writeOffsetTableEntry(got_entry_index) catch |err| switch (err) { |
| 1417 | | error.OutOfMemory => return error.OutOfMemory, |
| 1418 | | else => |e| return coff.base.cgFail(nav_index, "failed to write offset table entry: {s}", .{@errorName(e)}), |
| 1419 | | }; |
| 1420 | | coff.markRelocsDirtyByTarget(.{ .sym_index = sym_index }); |
| 1421 | | } |
| 1422 | | } else if (code_len < atom.size) { |
| 1423 | | coff.shrinkAtom(atom_index, code_len); |
| 1424 | | } |
| 1425 | | coff.getAtomPtr(atom_index).size = code_len; |
| 1426 | | } else { |
| 1427 | | const sym = atom.getSymbolPtr(coff); |
| 1428 | | try coff.setSymbolName(sym, nav.fqn.toSlice(ip)); |
| 1429 | | sym.section_number = @enumFromInt(sect_index + 1); |
| 1430 | | sym.type = .{ .complex_type = complex_type, .base_type = .NULL }; |
| 1431 | | |
| 1432 | | const vaddr = coff.allocateAtom(atom_index, code_len, @intCast(required_alignment.toByteUnits() orelse 0)) catch |err| switch (err) { |
| 1433 | | error.OutOfMemory => return error.OutOfMemory, |
| 1434 | | else => |e| return coff.base.cgFail(nav_index, "failed to allocate atom: {s}", .{@errorName(e)}), |
| 1435 | | }; |
| 1436 | | errdefer coff.freeAtom(atom_index); |
| 1437 | | log.debug("allocated atom for {f} at 0x{x}", .{ nav.fqn.fmt(ip), vaddr }); |
| 1438 | | coff.getAtomPtr(atom_index).size = code_len; |
| 1439 | | sym.value = vaddr; |
| 1440 | | |
| 1441 | | coff.addGotEntry(.{ .sym_index = sym_index }) catch |err| switch (err) { |
| 1442 | | error.OutOfMemory => return error.OutOfMemory, |
| 1443 | | else => |e| return coff.base.cgFail(nav_index, "failed to add GOT entry: {s}", .{@errorName(e)}), |
| 1444 | | }; |
| 1445 | | } |
| 1446 | | |
| 1447 | | coff.writeAtom(atom_index, code, coff.base.comp.config.incremental) catch |err| switch (err) { |
| 1448 | | error.OutOfMemory => return error.OutOfMemory, |
| 1449 | | else => |e| return coff.base.cgFail(nav_index, "failed to write atom: {s}", .{@errorName(e)}), |
| 1450 | | }; |
| 1451 | | } |
| 1452 | | |
| 1453 | | pub fn freeNav(coff: *Coff, nav_index: InternPool.NavIndex) void { |
| 1454 | | const gpa = coff.base.comp.gpa; |
| 1455 | | |
| 1456 | | if (coff.decls.fetchOrderedRemove(nav_index)) |const_kv| { |
| 1457 | | var kv = const_kv; |
| 1458 | | coff.freeAtom(kv.value.atom); |
| 1459 | | kv.value.exports.deinit(gpa); |
| 1460 | | } |
| 1461 | | } |
| 1462 | | |
| 1463 | | pub fn updateExports( |
| 1464 | | coff: *Coff, |
| 1465 | | pt: Zcu.PerThread, |
| 1466 | | exported: Zcu.Exported, |
| 1467 | | export_indices: []const Zcu.Export.Index, |
| 1468 | | ) link.File.UpdateExportsError!void { |
| 1469 | | if (build_options.skip_non_native and builtin.object_format != .coff) { |
| 1470 | | @panic("Attempted to compile for object format that was disabled by build configuration"); |
| 1471 | | } |
| 1472 | | |
| 1473 | | const zcu = pt.zcu; |
| 1474 | | const gpa = zcu.gpa; |
| 1475 | | |
| 1476 | | const metadata = switch (exported) { |
| 1477 | | .nav => |nav| blk: { |
| 1478 | | _ = try coff.getOrCreateAtomForNav(nav); |
| 1479 | | break :blk coff.navs.getPtr(nav).?; |
| 1480 | | }, |
| 1481 | | .uav => |uav| coff.uavs.getPtr(uav) orelse blk: { |
| 1482 | | const first_exp = export_indices[0].ptr(zcu); |
| 1483 | | const res = try coff.lowerUav(pt, uav, .none, first_exp.src); |
| 1484 | | switch (res) { |
| 1485 | | .sym_index => {}, |
| 1486 | | .fail => |em| { |
| 1487 | | // TODO maybe it's enough to return an error here and let Module.processExportsInner |
| 1488 | | // handle the error? |
| 1489 | | try zcu.failed_exports.ensureUnusedCapacity(zcu.gpa, 1); |
| 1490 | | zcu.failed_exports.putAssumeCapacityNoClobber(export_indices[0], em); |
| 1491 | | return; |
| 1492 | | }, |
| 1493 | | } |
| 1494 | | break :blk coff.uavs.getPtr(uav).?; |
| 1495 | | }, |
| 1496 | | }; |
| 1497 | | const atom_index = metadata.atom; |
| 1498 | | const atom = coff.getAtom(atom_index); |
| 1499 | | |
| 1500 | | for (export_indices) |export_idx| { |
| 1501 | | const exp = export_idx.ptr(zcu); |
| 1502 | | log.debug("adding new export '{f}'", .{exp.opts.name.fmt(&zcu.intern_pool)}); |
| 1503 | | |
| 1504 | | if (exp.opts.section.toSlice(&zcu.intern_pool)) |section_name| { |
| 1505 | | if (!mem.eql(u8, section_name, ".text")) { |
| 1506 | | try zcu.failed_exports.putNoClobber(gpa, export_idx, try Zcu.ErrorMsg.create( |
| 1507 | | gpa, |
| 1508 | | exp.src, |
| 1509 | | "Unimplemented: ExportOptions.section", |
| 1510 | | .{}, |
| 1511 | | )); |
| 1512 | | continue; |
| 1513 | | } |
| 1514 | | } |
| 1515 | | |
| 1516 | | if (exp.opts.linkage == .link_once) { |
| 1517 | | try zcu.failed_exports.putNoClobber(gpa, export_idx, try Zcu.ErrorMsg.create( |
| 1518 | | gpa, |
| 1519 | | exp.src, |
| 1520 | | "Unimplemented: GlobalLinkage.link_once", |
| 1521 | | .{}, |
| 1522 | | )); |
| 1523 | | continue; |
| 1524 | | } |
| 1525 | | |
| 1526 | | const exp_name = exp.opts.name.toSlice(&zcu.intern_pool); |
| 1527 | | const sym_index = metadata.getExport(coff, exp_name) orelse blk: { |
| 1528 | | const sym_index = if (coff.getGlobalIndex(exp_name)) |global_index| ind: { |
| 1529 | | const global = coff.globals.items[global_index]; |
| 1530 | | // TODO this is just plain wrong as it all should happen in a single `resolveSymbols` |
| 1531 | | // pass. This will go away once we abstact away Zig's incremental compilation into |
| 1532 | | // its own module. |
| 1533 | | if (global.file == null and coff.getSymbol(global).section_number == .UNDEFINED) { |
| 1534 | | _ = coff.unresolved.swapRemove(global_index); |
| 1535 | | break :ind global.sym_index; |
| 1536 | | } |
| 1537 | | break :ind try coff.allocateSymbol(); |
| 1538 | | } else try coff.allocateSymbol(); |
| 1539 | | try metadata.exports.append(gpa, sym_index); |
| 1540 | | break :blk sym_index; |
| 1541 | | }; |
| 1542 | | const sym_loc = SymbolWithLoc{ .sym_index = sym_index, .file = null }; |
| 1543 | | const sym = coff.getSymbolPtr(sym_loc); |
| 1544 | | try coff.setSymbolName(sym, exp_name); |
| 1545 | | sym.value = atom.getSymbol(coff).value; |
| 1546 | | sym.section_number = @as(coff_util.SectionNumber, @enumFromInt(metadata.section + 1)); |
| 1547 | | sym.type = atom.getSymbol(coff).type; |
| 1548 | | |
| 1549 | | sym.storage_class = switch (exp.opts.linkage) { |
| 1550 | | .internal => .EXTERNAL, |
| 1551 | | .strong => .EXTERNAL, |
| 1552 | | .weak => @panic("TODO WeakExternal"), |
| 1553 | | else => unreachable, |
| 1554 | | }; |
| 1555 | | |
| 1556 | | try coff.resolveGlobalSymbol(sym_loc); |
| 1557 | | } |
| 1558 | | } |
| 1559 | | |
| 1560 | | pub fn deleteExport( |
| 1561 | | coff: *Coff, |
| 1562 | | exported: Zcu.Exported, |
| 1563 | | name: InternPool.NullTerminatedString, |
| 1564 | | ) void { |
| 1565 | | const metadata = switch (exported) { |
| 1566 | | .nav => |nav| coff.navs.getPtr(nav), |
| 1567 | | .uav => |uav| coff.uavs.getPtr(uav), |
| 1568 | | } orelse return; |
| 1569 | | const zcu = coff.base.comp.zcu.?; |
| 1570 | | const name_slice = name.toSlice(&zcu.intern_pool); |
| 1571 | | const sym_index = metadata.getExportPtr(coff, name_slice) orelse return; |
| 1572 | | |
| 1573 | | const gpa = coff.base.comp.gpa; |
| 1574 | | const sym_loc = SymbolWithLoc{ .sym_index = sym_index.*, .file = null }; |
| 1575 | | const sym = coff.getSymbolPtr(sym_loc); |
| 1576 | | log.debug("deleting export '{f}'", .{name.fmt(&zcu.intern_pool)}); |
| 1577 | | assert(sym.storage_class == .EXTERNAL and sym.section_number != .UNDEFINED); |
| 1578 | | sym.* = .{ |
| 1579 | | .name = [_]u8{0} ** 8, |
| 1580 | | .value = 0, |
| 1581 | | .section_number = .UNDEFINED, |
| 1582 | | .type = .{ .base_type = .NULL, .complex_type = .NULL }, |
| 1583 | | .storage_class = .NULL, |
| 1584 | | .number_of_aux_symbols = 0, |
| 1585 | | }; |
| 1586 | | coff.locals_free_list.append(gpa, sym_index.*) catch {}; |
| 1587 | | |
| 1588 | | if (coff.resolver.fetchRemove(name_slice)) |entry| { |
| 1589 | | defer gpa.free(entry.key); |
| 1590 | | coff.globals_free_list.append(gpa, entry.value) catch {}; |
| 1591 | | coff.globals.items[entry.value] = .{ |
| 1592 | | .sym_index = 0, |
| 1593 | | .file = null, |
| 1594 | | }; |
| 1595 | | } |
| 1596 | | |
| 1597 | | sym_index.* = 0; |
| 1598 | | } |
| 1599 | | |
| 1600 | | fn resolveGlobalSymbol(coff: *Coff, current: SymbolWithLoc) !void { |
| 1601 | | const gpa = coff.base.comp.gpa; |
| 1602 | | const sym = coff.getSymbol(current); |
| 1603 | | const sym_name = coff.getSymbolName(current); |
| 1604 | | |
| 1605 | | const gop = try coff.getOrPutGlobalPtr(sym_name); |
| 1606 | | if (!gop.found_existing) { |
| 1607 | | gop.value_ptr.* = current; |
| 1608 | | if (sym.section_number == .UNDEFINED) { |
| 1609 | | try coff.unresolved.putNoClobber(gpa, coff.getGlobalIndex(sym_name).?, false); |
| 1610 | | } |
| 1611 | | return; |
| 1612 | | } |
| 1613 | | |
| 1614 | | log.debug("TODO finish resolveGlobalSymbols implementation", .{}); |
| 1615 | | |
| 1616 | | if (sym.section_number == .UNDEFINED) return; |
| 1617 | | |
| 1618 | | _ = coff.unresolved.swapRemove(coff.getGlobalIndex(sym_name).?); |
| 1619 | | |
| 1620 | | gop.value_ptr.* = current; |
| 1621 | | } |
| 1622 | | |
| 1623 | | pub fn flush( |
| 1624 | | coff: *Coff, |
| 1625 | | arena: Allocator, |
| 1626 | | tid: Zcu.PerThread.Id, |
| 1627 | | prog_node: std.Progress.Node, |
| 1628 | | ) link.File.FlushError!void { |
| 1629 | | const tracy = trace(@src()); |
| 1630 | | defer tracy.end(); |
| 1631 | | |
| 1632 | | const comp = coff.base.comp; |
| 1633 | | const diags = &comp.link_diags; |
| 1634 | | |
| 1635 | | switch (coff.base.comp.config.output_mode) { |
| 1636 | | .Exe, .Obj => {}, |
| 1637 | | .Lib => return diags.fail("writing lib files not yet implemented for COFF", .{}), |
| 1638 | | } |
| 1639 | | |
| 1640 | | const sub_prog_node = prog_node.start("COFF Flush", 0); |
| 1641 | | defer sub_prog_node.end(); |
| 1642 | | |
| 1643 | | return flushInner(coff, arena, tid) catch |err| switch (err) { |
| 1644 | | error.OutOfMemory => return error.OutOfMemory, |
| 1645 | | error.LinkFailure => return error.LinkFailure, |
| 1646 | | else => |e| return diags.fail("COFF flush failed: {s}", .{@errorName(e)}), |
| 1647 | | }; |
| 1648 | | } |
| 1649 | | |
| 1650 | | fn flushInner(coff: *Coff, arena: Allocator, tid: Zcu.PerThread.Id) !void { |
| 1651 | | _ = arena; |
| 1652 | | |
| 1653 | | const comp = coff.base.comp; |
| 1654 | | const gpa = comp.gpa; |
| 1655 | | const diags = &comp.link_diags; |
| 1656 | | |
| 1657 | | const pt: Zcu.PerThread = .activate( |
| 1658 | | comp.zcu orelse return diags.fail("linking without zig source is not yet implemented", .{}), |
| 1659 | | tid, |
| 1660 | | ); |
| 1661 | | defer pt.deactivate(); |
| 1662 | | |
| 1663 | | if (coff.lazy_syms.getPtr(.anyerror_type)) |metadata| { |
| 1664 | | // Most lazy symbols can be updated on first use, but |
| 1665 | | // anyerror needs to wait for everything to be flushed. |
| 1666 | | if (metadata.text_state != .unused) try coff.updateLazySymbolAtom( |
| 1667 | | pt, |
| 1668 | | .{ .kind = .code, .ty = .anyerror_type }, |
| 1669 | | metadata.text_atom, |
| 1670 | | coff.text_section_index.?, |
| 1671 | | ); |
| 1672 | | if (metadata.rdata_state != .unused) try coff.updateLazySymbolAtom( |
| 1673 | | pt, |
| 1674 | | .{ .kind = .const_data, .ty = .anyerror_type }, |
| 1675 | | metadata.rdata_atom, |
| 1676 | | coff.rdata_section_index.?, |
| 1677 | | ); |
| 1678 | | } |
| 1679 | | for (coff.lazy_syms.values()) |*metadata| { |
| 1680 | | if (metadata.text_state != .unused) metadata.text_state = .flushed; |
| 1681 | | if (metadata.rdata_state != .unused) metadata.rdata_state = .flushed; |
| 1682 | | } |
| 1683 | | |
| 1684 | | { |
| 1685 | | var it = coff.need_got_table.iterator(); |
| 1686 | | while (it.next()) |entry| { |
| 1687 | | const global = coff.globals.items[entry.key_ptr.*]; |
| 1688 | | try coff.addGotEntry(global); |
| 1689 | | } |
| 1690 | | } |
| 1691 | | |
| 1692 | | while (coff.unresolved.pop()) |entry| { |
| 1693 | | assert(entry.value); |
| 1694 | | const global = coff.globals.items[entry.key]; |
| 1695 | | const sym = coff.getSymbol(global); |
| 1696 | | const res = try coff.import_tables.getOrPut(gpa, sym.value); |
| 1697 | | const itable = res.value_ptr; |
| 1698 | | if (!res.found_existing) { |
| 1699 | | itable.* = .{}; |
| 1700 | | } |
| 1701 | | if (itable.lookup.contains(global)) continue; |
| 1702 | | // TODO: we could technically write the pointer placeholder for to-be-bound import here, |
| 1703 | | // but since this happens in flush, there is currently no point. |
| 1704 | | _ = try itable.addImport(gpa, global); |
| 1705 | | coff.imports_count_dirty = true; |
| 1706 | | } |
| 1707 | | |
| 1708 | | try coff.writeImportTables(); |
| 1709 | | |
| 1710 | | for (coff.relocs.keys(), coff.relocs.values()) |atom_index, relocs| { |
| 1711 | | const needs_update = for (relocs.items) |reloc| { |
| 1712 | | if (reloc.dirty) break true; |
| 1713 | | } else false; |
| 1714 | | |
| 1715 | | if (!needs_update) continue; |
| 1716 | | |
| 1717 | | const atom = coff.getAtom(atom_index); |
| 1718 | | const sym = atom.getSymbol(coff); |
| 1719 | | const section = coff.sections.get(@intFromEnum(sym.section_number) - 1).header; |
| 1720 | | const file_offset = section.pointer_to_raw_data + sym.value - section.virtual_address; |
| 1721 | | |
| 1722 | | var code = std.array_list.Managed(u8).init(gpa); |
| 1723 | | defer code.deinit(); |
| 1724 | | try code.resize(math.cast(usize, atom.size) orelse return error.Overflow); |
| 1725 | | assert(atom.size > 0); |
| 1726 | | |
| 1727 | | const amt = try coff.base.file.?.preadAll(code.items, file_offset); |
| 1728 | | if (amt != code.items.len) return error.InputOutput; |
| 1729 | | |
| 1730 | | try coff.writeAtom(atom_index, code.items, true); |
| 1731 | | } |
| 1732 | | |
| 1733 | | // Update GOT if it got moved in memory. |
| 1734 | | if (coff.got_table_contents_dirty) { |
| 1735 | | for (coff.got_table.entries.items, 0..) |entry, i| { |
| 1736 | | if (!coff.got_table.lookup.contains(entry)) continue; |
| 1737 | | // TODO: write all in one go rather than incrementally. |
| 1738 | | try coff.writeOffsetTableEntry(i); |
| 1739 | | } |
| 1740 | | coff.got_table_contents_dirty = false; |
| 1741 | | } |
| 1742 | | |
| 1743 | | try coff.writeBaseRelocations(); |
| 1744 | | |
| 1745 | | if (coff.getEntryPoint()) |entry_sym_loc| { |
| 1746 | | coff.entry_addr = coff.getSymbol(entry_sym_loc).value; |
| 1747 | | } |
| 1748 | | |
| 1749 | | if (build_options.enable_logging) { |
| 1750 | | coff.logSymtab(); |
| 1751 | | coff.logImportTables(); |
| 1752 | | } |
| 1753 | | |
| 1754 | | try coff.writeStrtab(); |
| 1755 | | try coff.writeDataDirectoriesHeaders(); |
| 1756 | | try coff.writeSectionHeaders(); |
| 1757 | | |
| 1758 | | if (coff.entry_addr == null and comp.config.output_mode == .Exe) { |
| 1759 | | log.debug("flushing. no_entry_point_found = true\n", .{}); |
| 1760 | | diags.flags.no_entry_point_found = true; |
| 1761 | | } else { |
| 1762 | | log.debug("flushing. no_entry_point_found = false\n", .{}); |
| 1763 | | diags.flags.no_entry_point_found = false; |
| 1764 | | try coff.writeHeader(); |
| 1765 | | } |
| 1766 | | |
| 1767 | | assert(!coff.imports_count_dirty); |
| 1768 | | |
| 1769 | | // hack for stage2_x86_64 + coff |
| 1770 | | if (comp.compiler_rt_dyn_lib) |crt_file| { |
| 1771 | | const compiler_rt_sub_path = try std.fs.path.join(gpa, &.{ |
| 1772 | | std.fs.path.dirname(coff.base.emit.sub_path) orelse "", |
| 1773 | | std.fs.path.basename(crt_file.full_object_path.sub_path), |
| 1774 | | }); |
| 1775 | | defer gpa.free(compiler_rt_sub_path); |
| 1776 | | try crt_file.full_object_path.root_dir.handle.copyFile( |
| 1777 | | crt_file.full_object_path.sub_path, |
| 1778 | | coff.base.emit.root_dir.handle, |
| 1779 | | compiler_rt_sub_path, |
| 1780 | | .{}, |
| 1781 | | ); |
| 1782 | | } |
| 1783 | | } |
| 1784 | | |
| 1785 | | pub fn getNavVAddr( |
| 1786 | | coff: *Coff, |
| 1787 | | pt: Zcu.PerThread, |
| 1788 | | nav_index: InternPool.Nav.Index, |
| 1789 | | reloc_info: link.File.RelocInfo, |
| 1790 | | ) !u64 { |
| 1791 | | const zcu = pt.zcu; |
| 1792 | | const ip = &zcu.intern_pool; |
| 1793 | | const nav = ip.getNav(nav_index); |
| 1794 | | log.debug("getNavVAddr {f}({d})", .{ nav.fqn.fmt(ip), nav_index }); |
| 1795 | | const sym_index = if (nav.getExtern(ip)) |e| |
| 1796 | | try coff.getGlobalSymbol(nav.name.toSlice(ip), e.lib_name.toSlice(ip)) |
| 1797 | | else |
| 1798 | | coff.getAtom(try coff.getOrCreateAtomForNav(nav_index)).getSymbolIndex().?; |
| 1799 | | const atom_index = coff.getAtomIndexForSymbol(.{ |
| 1800 | | .sym_index = reloc_info.parent.atom_index, |
| 1801 | | .file = null, |
| 1802 | | }).?; |
| 1803 | | const target = SymbolWithLoc{ .sym_index = sym_index, .file = null }; |
| 1804 | | try coff.addRelocation(atom_index, .{ |
| 1805 | | .type = .direct, |
| 1806 | | .target = target, |
| 1807 | | .offset = @as(u32, @intCast(reloc_info.offset)), |
| 1808 | | .addend = reloc_info.addend, |
| 1809 | | .pcrel = false, |
| 1810 | | .length = 3, |
| 1811 | | }); |
| 1812 | | try coff.addBaseRelocation(atom_index, @as(u32, @intCast(reloc_info.offset))); |
| 1813 | | |
| 1814 | | return 0; |
| 1815 | | } |
| 1816 | | |
| 1817 | | pub fn lowerUav( |
| 1818 | | coff: *Coff, |
| 1819 | | pt: Zcu.PerThread, |
| 1820 | | uav: InternPool.Index, |
| 1821 | | explicit_alignment: InternPool.Alignment, |
| 1822 | | src_loc: Zcu.LazySrcLoc, |
| 1823 | | ) !codegen.SymbolResult { |
| 1824 | | const zcu = pt.zcu; |
| 1825 | | const gpa = zcu.gpa; |
| 1826 | | const val = Value.fromInterned(uav); |
| 1827 | | const uav_alignment = switch (explicit_alignment) { |
| 1828 | | .none => val.typeOf(zcu).abiAlignment(zcu), |
| 1829 | | else => explicit_alignment, |
| 1830 | | }; |
| 1831 | | if (coff.uavs.get(uav)) |metadata| { |
| 1832 | | const atom = coff.getAtom(metadata.atom); |
| 1833 | | const existing_addr = atom.getSymbol(coff).value; |
| 1834 | | if (uav_alignment.check(existing_addr)) |
| 1835 | | return .{ .sym_index = atom.getSymbolIndex().? }; |
| 1836 | | } |
| 1837 | | |
| 1838 | | var name_buf: [32]u8 = undefined; |
| 1839 | | const name = std.fmt.bufPrint(&name_buf, "__anon_{d}", .{ |
| 1840 | | @intFromEnum(uav), |
| 1841 | | }) catch unreachable; |
| 1842 | | const res = coff.lowerConst( |
| 1843 | | pt, |
| 1844 | | name, |
| 1845 | | val, |
| 1846 | | uav_alignment, |
| 1847 | | coff.rdata_section_index.?, |
| 1848 | | src_loc, |
| 1849 | | ) catch |err| switch (err) { |
| 1850 | | error.OutOfMemory => return error.OutOfMemory, |
| 1851 | | else => |e| return .{ .fail = try Zcu.ErrorMsg.create( |
| 1852 | | gpa, |
| 1853 | | src_loc, |
| 1854 | | "lowerAnonDecl failed with error: {s}", |
| 1855 | | .{@errorName(e)}, |
| 1856 | | ) }, |
| 1857 | | }; |
| 1858 | | const atom_index = switch (res) { |
| 1859 | | .ok => |atom_index| atom_index, |
| 1860 | | .fail => |em| return .{ .fail = em }, |
| 1861 | | }; |
| 1862 | | try coff.uavs.put(gpa, uav, .{ |
| 1863 | | .atom = atom_index, |
| 1864 | | .section = coff.rdata_section_index.?, |
| 1865 | | }); |
| 1866 | | return .{ .sym_index = coff.getAtom(atom_index).getSymbolIndex().? }; |
| 1867 | | } |
| 1868 | | |
| 1869 | | pub fn getUavVAddr( |
| 1870 | | coff: *Coff, |
| 1871 | | uav: InternPool.Index, |
| 1872 | | reloc_info: link.File.RelocInfo, |
| 1873 | | ) !u64 { |
| 1874 | | const this_atom_index = coff.uavs.get(uav).?.atom; |
| 1875 | | const sym_index = coff.getAtom(this_atom_index).getSymbolIndex().?; |
| 1876 | | const atom_index = coff.getAtomIndexForSymbol(.{ |
| 1877 | | .sym_index = reloc_info.parent.atom_index, |
| 1878 | | .file = null, |
| 1879 | | }).?; |
| 1880 | | const target = SymbolWithLoc{ .sym_index = sym_index, .file = null }; |
| 1881 | | try coff.addRelocation(atom_index, .{ |
| 1882 | | .type = .direct, |
| 1883 | | .target = target, |
| 1884 | | .offset = @as(u32, @intCast(reloc_info.offset)), |
| 1885 | | .addend = reloc_info.addend, |
| 1886 | | .pcrel = false, |
| 1887 | | .length = 3, |
| 1888 | | }); |
| 1889 | | try coff.addBaseRelocation(atom_index, @as(u32, @intCast(reloc_info.offset))); |
| 1890 | | |
| 1891 | | return 0; |
| 1892 | | } |
| 1893 | | |
| 1894 | | pub fn getGlobalSymbol(coff: *Coff, name: []const u8, lib_name_name: ?[]const u8) !u32 { |
| 1895 | | const gop = try coff.getOrPutGlobalPtr(name); |
| 1896 | | const global_index = coff.getGlobalIndex(name).?; |
| 1897 | | |
| 1898 | | if (gop.found_existing) { |
| 1899 | | return global_index; |
| 1900 | | } |
| 1901 | | |
| 1902 | | const sym_index = try coff.allocateSymbol(); |
| 1903 | | const sym_loc = SymbolWithLoc{ .sym_index = sym_index, .file = null }; |
| 1904 | | gop.value_ptr.* = sym_loc; |
| 1905 | | |
| 1906 | | const gpa = coff.base.comp.gpa; |
| 1907 | | const sym = coff.getSymbolPtr(sym_loc); |
| 1908 | | try coff.setSymbolName(sym, name); |
| 1909 | | sym.storage_class = .EXTERNAL; |
| 1910 | | |
| 1911 | | if (lib_name_name) |lib_name| { |
| 1912 | | // We repurpose the 'value' of the Symbol struct to store an offset into |
| 1913 | | // temporary string table where we will store the library name hint. |
| 1914 | | sym.value = try coff.temp_strtab.insert(gpa, lib_name); |
| 1915 | | } |
| 1916 | | |
| 1917 | | try coff.unresolved.putNoClobber(gpa, global_index, true); |
| 1918 | | |
| 1919 | | return global_index; |
| 1920 | | } |
| 1921 | | |
| 1922 | | pub fn updateLineNumber(coff: *Coff, pt: Zcu.PerThread, ti_id: InternPool.TrackedInst.Index) !void { |
| 1923 | | _ = coff; |
| 1924 | | _ = pt; |
| 1925 | | _ = ti_id; |
| 1926 | | log.debug("TODO implement updateLineNumber", .{}); |
| 1927 | | } |
| 1928 | | |
| 1929 | | /// TODO: note if we need to rewrite base relocations by dirtying any of the entries in the global table |
| 1930 | | /// TODO: note that .ABSOLUTE is used as padding within each block; we could use this fact to do |
| 1931 | | /// incremental updates and writes into the table instead of doing it all at once |
| 1932 | | fn writeBaseRelocations(coff: *Coff) !void { |
| 1933 | | const gpa = coff.base.comp.gpa; |
| 1934 | | |
| 1935 | | var page_table = std.AutoHashMap(u32, std.array_list.Managed(coff_util.BaseRelocation)).init(gpa); |
| 1936 | | defer { |
| 1937 | | var it = page_table.valueIterator(); |
| 1938 | | while (it.next()) |inner| { |
| 1939 | | inner.deinit(); |
| 1940 | | } |
| 1941 | | page_table.deinit(); |
| 1942 | | } |
| 1943 | | |
| 1944 | | { |
| 1945 | | var it = coff.base_relocs.iterator(); |
| 1946 | | while (it.next()) |entry| { |
| 1947 | | const atom_index = entry.key_ptr.*; |
| 1948 | | const atom = coff.getAtom(atom_index); |
| 1949 | | const sym = atom.getSymbol(coff); |
| 1950 | | const offsets = entry.value_ptr.*; |
| 1951 | | |
| 1952 | | for (offsets.items) |offset| { |
| 1953 | | const rva = sym.value + offset; |
| 1954 | | const page = mem.alignBackward(u32, rva, coff.page_size); |
| 1955 | | const gop = try page_table.getOrPut(page); |
| 1956 | | if (!gop.found_existing) { |
| 1957 | | gop.value_ptr.* = std.array_list.Managed(coff_util.BaseRelocation).init(gpa); |
| 1958 | | } |
| 1959 | | try gop.value_ptr.append(.{ |
| 1960 | | .offset = @as(u12, @intCast(rva - page)), |
| 1961 | | .type = .DIR64, |
| 1962 | | }); |
| 1963 | | } |
| 1964 | | } |
| 1965 | | |
| 1966 | | { |
| 1967 | | const header = &coff.sections.items(.header)[coff.got_section_index.?]; |
| 1968 | | for (coff.got_table.entries.items, 0..) |entry, index| { |
| 1969 | | if (!coff.got_table.lookup.contains(entry)) continue; |
| 1970 | | |
| 1971 | | const sym = coff.getSymbol(entry); |
| 1972 | | if (sym.section_number == .UNDEFINED) continue; |
| 1973 | | |
| 1974 | | const rva = @as(u32, @intCast(header.virtual_address + index * coff.ptr_width.size())); |
| 1975 | | const page = mem.alignBackward(u32, rva, coff.page_size); |
| 1976 | | const gop = try page_table.getOrPut(page); |
| 1977 | | if (!gop.found_existing) { |
| 1978 | | gop.value_ptr.* = std.array_list.Managed(coff_util.BaseRelocation).init(gpa); |
| 1979 | | } |
| 1980 | | try gop.value_ptr.append(.{ |
| 1981 | | .offset = @as(u12, @intCast(rva - page)), |
| 1982 | | .type = .DIR64, |
| 1983 | | }); |
| 1984 | | } |
| 1985 | | } |
| 1986 | | } |
| 1987 | | |
| 1988 | | // Sort pages by address. |
| 1989 | | var pages = try std.array_list.Managed(u32).initCapacity(gpa, page_table.count()); |
| 1990 | | defer pages.deinit(); |
| 1991 | | { |
| 1992 | | var it = page_table.keyIterator(); |
| 1993 | | while (it.next()) |page| { |
| 1994 | | pages.appendAssumeCapacity(page.*); |
| 1995 | | } |
| 1996 | | } |
| 1997 | | mem.sort(u32, pages.items, {}, std.sort.asc(u32)); |
| 1998 | | |
| 1999 | | var buffer = std.array_list.Managed(u8).init(gpa); |
| 2000 | | defer buffer.deinit(); |
| 2001 | | |
| 2002 | | for (pages.items) |page| { |
| 2003 | | const entries = page_table.getPtr(page).?; |
| 2004 | | // Pad to required 4byte alignment |
| 2005 | | if (!mem.isAlignedGeneric( |
| 2006 | | usize, |
| 2007 | | entries.items.len * @sizeOf(coff_util.BaseRelocation), |
| 2008 | | @sizeOf(u32), |
| 2009 | | )) { |
| 2010 | | try entries.append(.{ |
| 2011 | | .offset = 0, |
| 2012 | | .type = .ABSOLUTE, |
| 2013 | | }); |
| 2014 | | } |
| 2015 | | |
| 2016 | | const block_size = @as( |
| 2017 | | u32, |
| 2018 | | @intCast(entries.items.len * @sizeOf(coff_util.BaseRelocation) + @sizeOf(coff_util.BaseRelocationDirectoryEntry)), |
| 2019 | | ); |
| 2020 | | try buffer.ensureUnusedCapacity(block_size); |
| 2021 | | buffer.appendSliceAssumeCapacity(mem.asBytes(&coff_util.BaseRelocationDirectoryEntry{ |
| 2022 | | .page_rva = page, |
| 2023 | | .block_size = block_size, |
| 2024 | | })); |
| 2025 | | buffer.appendSliceAssumeCapacity(mem.sliceAsBytes(entries.items)); |
| 2026 | | } |
| 2027 | | |
| 2028 | | const header = &coff.sections.items(.header)[coff.reloc_section_index.?]; |
| 2029 | | const needed_size = @as(u32, @intCast(buffer.items.len)); |
| 2030 | | try coff.growSection(coff.reloc_section_index.?, needed_size); |
| 2031 | | |
| 2032 | | try coff.pwriteAll(buffer.items, header.pointer_to_raw_data); |
| 2033 | | |
| 2034 | | coff.data_directories[@intFromEnum(coff_util.DirectoryEntry.BASERELOC)] = .{ |
| 2035 | | .virtual_address = header.virtual_address, |
| 2036 | | .size = needed_size, |
| 2037 | | }; |
| 2038 | | } |
| 2039 | | |
| 2040 | | fn writeImportTables(coff: *Coff) !void { |
| 2041 | | if (coff.idata_section_index == null) return; |
| 2042 | | if (!coff.imports_count_dirty) return; |
| 2043 | | |
| 2044 | | const gpa = coff.base.comp.gpa; |
| 2045 | | |
| 2046 | | const ext = ".dll"; |
| 2047 | | const header = &coff.sections.items(.header)[coff.idata_section_index.?]; |
| 2048 | | |
| 2049 | | // Calculate needed size |
| 2050 | | var iat_size: u32 = 0; |
| 2051 | | var dir_table_size: u32 = @sizeOf(coff_util.ImportDirectoryEntry); // sentinel |
| 2052 | | var lookup_table_size: u32 = 0; |
| 2053 | | var names_table_size: u32 = 0; |
| 2054 | | var dll_names_size: u32 = 0; |
| 2055 | | for (coff.import_tables.keys(), 0..) |off, i| { |
| 2056 | | const lib_name = coff.temp_strtab.getAssumeExists(off); |
| 2057 | | const itable = coff.import_tables.values()[i]; |
| 2058 | | iat_size += itable.size() + 8; |
| 2059 | | dir_table_size += @sizeOf(coff_util.ImportDirectoryEntry); |
| 2060 | | lookup_table_size += @as(u32, @intCast(itable.entries.items.len + 1)) * @sizeOf(coff_util.ImportLookupEntry64.ByName); |
| 2061 | | for (itable.entries.items) |entry| { |
| 2062 | | const sym_name = coff.getSymbolName(entry); |
| 2063 | | names_table_size += 2 + mem.alignForward(u32, @as(u32, @intCast(sym_name.len + 1)), 2); |
| 2064 | | } |
| 2065 | | dll_names_size += @as(u32, @intCast(lib_name.len + ext.len + 1)); |
| 2066 | | } |
| 2067 | | |
| 2068 | | const needed_size = iat_size + dir_table_size + lookup_table_size + names_table_size + dll_names_size; |
| 2069 | | try coff.growSection(coff.idata_section_index.?, needed_size); |
| 2070 | | |
| 2071 | | // Do the actual writes |
| 2072 | | var buffer = std.array_list.Managed(u8).init(gpa); |
| 2073 | | defer buffer.deinit(); |
| 2074 | | try buffer.ensureTotalCapacityPrecise(needed_size); |
| 2075 | | buffer.resize(needed_size) catch unreachable; |
| 2076 | | |
| 2077 | | const dir_header_size = @sizeOf(coff_util.ImportDirectoryEntry); |
| 2078 | | const lookup_entry_size = @sizeOf(coff_util.ImportLookupEntry64.ByName); |
| 2079 | | |
| 2080 | | var iat_offset: u32 = 0; |
| 2081 | | var dir_table_offset = iat_size; |
| 2082 | | var lookup_table_offset = dir_table_offset + dir_table_size; |
| 2083 | | var names_table_offset = lookup_table_offset + lookup_table_size; |
| 2084 | | var dll_names_offset = names_table_offset + names_table_size; |
| 2085 | | for (coff.import_tables.keys(), 0..) |off, i| { |
| 2086 | | const lib_name = coff.temp_strtab.getAssumeExists(off); |
| 2087 | | const itable = coff.import_tables.values()[i]; |
| 2088 | | |
| 2089 | | // Lookup table header |
| 2090 | | const lookup_header = coff_util.ImportDirectoryEntry{ |
| 2091 | | .import_lookup_table_rva = header.virtual_address + lookup_table_offset, |
| 2092 | | .time_date_stamp = 0, |
| 2093 | | .forwarder_chain = 0, |
| 2094 | | .name_rva = header.virtual_address + dll_names_offset, |
| 2095 | | .import_address_table_rva = header.virtual_address + iat_offset, |
| 2096 | | }; |
| 2097 | | @memcpy(buffer.items[dir_table_offset..][0..@sizeOf(coff_util.ImportDirectoryEntry)], mem.asBytes(&lookup_header)); |
| 2098 | | dir_table_offset += dir_header_size; |
| 2099 | | |
| 2100 | | for (itable.entries.items) |entry| { |
| 2101 | | const import_name = coff.getSymbolName(entry); |
| 2102 | | |
| 2103 | | // IAT and lookup table entry |
| 2104 | | const lookup = coff_util.ImportLookupEntry64.ByName{ .name_table_rva = @as(u31, @intCast(header.virtual_address + names_table_offset)) }; |
| 2105 | | @memcpy( |
| 2106 | | buffer.items[iat_offset..][0..@sizeOf(coff_util.ImportLookupEntry64.ByName)], |
| 2107 | | mem.asBytes(&lookup), |
| 2108 | | ); |
| 2109 | | iat_offset += lookup_entry_size; |
| 2110 | | @memcpy( |
| 2111 | | buffer.items[lookup_table_offset..][0..@sizeOf(coff_util.ImportLookupEntry64.ByName)], |
| 2112 | | mem.asBytes(&lookup), |
| 2113 | | ); |
| 2114 | | lookup_table_offset += lookup_entry_size; |
| 2115 | | |
| 2116 | | // Names table entry |
| 2117 | | mem.writeInt(u16, buffer.items[names_table_offset..][0..2], 0, .little); // Hint set to 0 until we learn how to parse DLLs |
| 2118 | | names_table_offset += 2; |
| 2119 | | @memcpy(buffer.items[names_table_offset..][0..import_name.len], import_name); |
| 2120 | | names_table_offset += @as(u32, @intCast(import_name.len)); |
| 2121 | | buffer.items[names_table_offset] = 0; |
| 2122 | | names_table_offset += 1; |
| 2123 | | if (!mem.isAlignedGeneric(usize, names_table_offset, @sizeOf(u16))) { |
| 2124 | | buffer.items[names_table_offset] = 0; |
| 2125 | | names_table_offset += 1; |
| 2126 | | } |
| 2127 | | } |
| 2128 | | |
| 2129 | | // IAT sentinel |
| 2130 | | mem.writeInt(u64, buffer.items[iat_offset..][0..lookup_entry_size], 0, .little); |
| 2131 | | iat_offset += 8; |
| 2132 | | |
| 2133 | | // Lookup table sentinel |
| 2134 | | @memcpy( |
| 2135 | | buffer.items[lookup_table_offset..][0..@sizeOf(coff_util.ImportLookupEntry64.ByName)], |
| 2136 | | mem.asBytes(&coff_util.ImportLookupEntry64.ByName{ .name_table_rva = 0 }), |
| 2137 | | ); |
| 2138 | | lookup_table_offset += lookup_entry_size; |
| 2139 | | |
| 2140 | | // DLL name |
| 2141 | | @memcpy(buffer.items[dll_names_offset..][0..lib_name.len], lib_name); |
| 2142 | | dll_names_offset += @as(u32, @intCast(lib_name.len)); |
| 2143 | | @memcpy(buffer.items[dll_names_offset..][0..ext.len], ext); |
| 2144 | | dll_names_offset += @as(u32, @intCast(ext.len)); |
| 2145 | | buffer.items[dll_names_offset] = 0; |
| 2146 | | dll_names_offset += 1; |
| 2147 | | } |
| 2148 | | |
| 2149 | | // Sentinel |
| 2150 | | const lookup_header = coff_util.ImportDirectoryEntry{ |
| 2151 | | .import_lookup_table_rva = 0, |
| 2152 | | .time_date_stamp = 0, |
| 2153 | | .forwarder_chain = 0, |
| 2154 | | .name_rva = 0, |
| 2155 | | .import_address_table_rva = 0, |
| 2156 | | }; |
| 2157 | | @memcpy( |
| 2158 | | buffer.items[dir_table_offset..][0..@sizeOf(coff_util.ImportDirectoryEntry)], |
| 2159 | | mem.asBytes(&lookup_header), |
| 2160 | | ); |
| 2161 | | dir_table_offset += dir_header_size; |
| 2162 | | |
| 2163 | | assert(dll_names_offset == needed_size); |
| 2164 | | |
| 2165 | | try coff.pwriteAll(buffer.items, header.pointer_to_raw_data); |
| 2166 | | |
| 2167 | | coff.data_directories[@intFromEnum(coff_util.DirectoryEntry.IMPORT)] = .{ |
| 2168 | | .virtual_address = header.virtual_address + iat_size, |
| 2169 | | .size = dir_table_size, |
| 2170 | | }; |
| 2171 | | coff.data_directories[@intFromEnum(coff_util.DirectoryEntry.IAT)] = .{ |
| 2172 | | .virtual_address = header.virtual_address, |
| 2173 | | .size = iat_size, |
| 2174 | | }; |
| 2175 | | |
| 2176 | | coff.imports_count_dirty = false; |
| 2177 | | } |
| 2178 | | |
| 2179 | | fn writeStrtab(coff: *Coff) !void { |
| 2180 | | if (coff.strtab_offset == null) return; |
| 2181 | | |
| 2182 | | const comp = coff.base.comp; |
| 2183 | | const gpa = comp.gpa; |
| 2184 | | const diags = &comp.link_diags; |
| 2185 | | const allocated_size = coff.allocatedSize(coff.strtab_offset.?); |
| 2186 | | const needed_size: u32 = @intCast(coff.strtab.buffer.items.len); |
| 2187 | | |
| 2188 | | if (needed_size > allocated_size) { |
| 2189 | | coff.strtab_offset = null; |
| 2190 | | coff.strtab_offset = @intCast(coff.findFreeSpace(needed_size, @alignOf(u32))); |
| 2191 | | } |
| 2192 | | |
| 2193 | | log.debug("writing strtab from 0x{x} to 0x{x}", .{ coff.strtab_offset.?, coff.strtab_offset.? + needed_size }); |
| 2194 | | |
| 2195 | | var buffer = std.array_list.Managed(u8).init(gpa); |
| 2196 | | defer buffer.deinit(); |
| 2197 | | try buffer.ensureTotalCapacityPrecise(needed_size); |
| 2198 | | buffer.appendSliceAssumeCapacity(coff.strtab.buffer.items); |
| 2199 | | // Here, we do a trick in that we do not commit the size of the strtab to strtab buffer, instead |
| 2200 | | // we write the length of the strtab to a temporary buffer that goes to file. |
| 2201 | | mem.writeInt(u32, buffer.items[0..4], @as(u32, @intCast(coff.strtab.buffer.items.len)), .little); |
| 2202 | | |
| 2203 | | coff.pwriteAll(buffer.items, coff.strtab_offset.?) catch |err| { |
| 2204 | | return diags.fail("failed to write: {s}", .{@errorName(err)}); |
| 2205 | | }; |
| 2206 | | } |
| 2207 | | |
| 2208 | | fn writeSectionHeaders(coff: *Coff) !void { |
| 2209 | | const offset = coff.getSectionHeadersOffset(); |
| 2210 | | try coff.pwriteAll(@ptrCast(coff.sections.items(.header)), offset); |
| 2211 | | } |
| 2212 | | |
| 2213 | | fn writeDataDirectoriesHeaders(coff: *Coff) !void { |
| 2214 | | const offset = coff.getDataDirectoryHeadersOffset(); |
| 2215 | | try coff.pwriteAll(@ptrCast(&coff.data_directories), offset); |
| 2216 | | } |
| 2217 | | |
| 2218 | | fn writeHeader(coff: *Coff) !void { |
| 2219 | | const target = &coff.base.comp.root_mod.resolved_target.result; |
| 2220 | | const gpa = coff.base.comp.gpa; |
| 2221 | | var buffer: std.Io.Writer.Allocating = .init(gpa); |
| 2222 | | defer buffer.deinit(); |
| 2223 | | const writer = &buffer.writer; |
| 2224 | | |
| 2225 | | try buffer.ensureTotalCapacity(coff.getSizeOfHeaders()); |
| 2226 | | writer.writeAll(&msdos_stub) catch unreachable; |
| 2227 | | mem.writeInt(u32, buffer.writer.buffer[0x3c..][0..4], msdos_stub.len, .little); |
| 2228 | | |
| 2229 | | writer.writeAll("PE\x00\x00") catch unreachable; |
| 2230 | | var flags: coff_util.Header.Flags = .{ |
| 2231 | | .EXECUTABLE_IMAGE = true, |
| 2232 | | .DEBUG_STRIPPED = true, // TODO |
| 2233 | | }; |
| 2234 | | switch (coff.ptr_width) { |
| 2235 | | .p32 => flags.@"32BIT_MACHINE" = true, |
| 2236 | | .p64 => flags.LARGE_ADDRESS_AWARE = true, |
| 2237 | | } |
| 2238 | | if (coff.base.comp.config.output_mode == .Lib and coff.base.comp.config.link_mode == .dynamic) { |
| 2239 | | flags.DLL = true; |
| 2240 | | } |
| 2241 | | |
| 2242 | | const timestamp = if (coff.repro) 0 else std.time.timestamp(); |
| 2243 | | const size_of_optional_header = @as(u16, @intCast(coff.getOptionalHeaderSize() + coff.getDataDirectoryHeadersSize())); |
| 2244 | | var coff_header: coff_util.Header = .{ |
| 2245 | | .machine = target.toCoffMachine(), |
| 2246 | | .number_of_sections = @as(u16, @intCast(coff.sections.slice().len)), // TODO what if we prune a section |
| 2247 | | .time_date_stamp = @as(u32, @truncate(@as(u64, @bitCast(timestamp)))), |
| 2248 | | .pointer_to_symbol_table = coff.strtab_offset orelse 0, |
| 2249 | | .number_of_symbols = 0, |
| 2250 | | .size_of_optional_header = size_of_optional_header, |
| 2251 | | .flags = flags, |
| 2252 | | }; |
| 2253 | | |
| 2254 | | writer.writeAll(mem.asBytes(&coff_header)) catch unreachable; |
| 2255 | | |
| 2256 | | const dll_flags: coff_util.DllFlags = .{ |
| 2257 | | .HIGH_ENTROPY_VA = true, // TODO do we want to permit non-PIE builds at all? |
| 2258 | | .DYNAMIC_BASE = true, |
| 2259 | | .TERMINAL_SERVER_AWARE = true, // We are not a legacy app |
| 2260 | | .NX_COMPAT = true, // We are compatible with Data Execution Prevention |
| 2261 | | }; |
| 2262 | | const subsystem: coff_util.Subsystem = .WINDOWS_CUI; |
| 2263 | | const size_of_image: u32 = coff.getSizeOfImage(); |
| 2264 | | const size_of_headers: u32 = mem.alignForward(u32, coff.getSizeOfHeaders(), default_file_alignment); |
| 2265 | | const base_of_code = coff.sections.get(coff.text_section_index.?).header.virtual_address; |
| 2266 | | const base_of_data = coff.sections.get(coff.data_section_index.?).header.virtual_address; |
| 2267 | | |
| 2268 | | var size_of_code: u32 = 0; |
| 2269 | | var size_of_initialized_data: u32 = 0; |
| 2270 | | var size_of_uninitialized_data: u32 = 0; |
| 2271 | | for (coff.sections.items(.header)) |header| { |
| 2272 | | if (header.flags.CNT_CODE) { |
| 2273 | | size_of_code += header.size_of_raw_data; |
| 2274 | | } |
| 2275 | | if (header.flags.CNT_INITIALIZED_DATA) { |
| 2276 | | size_of_initialized_data += header.size_of_raw_data; |
| 2277 | | } |
| 2278 | | if (header.flags.CNT_UNINITIALIZED_DATA) { |
| 2279 | | size_of_uninitialized_data += header.size_of_raw_data; |
| 2280 | | } |
| 2281 | | } |
| 2282 | | |
| 2283 | | switch (coff.ptr_width) { |
| 2284 | | .p32 => { |
| 2285 | | var opt_header = coff_util.OptionalHeaderPE32{ |
| 2286 | | .magic = .PE32, |
| 2287 | | .major_linker_version = 0, |
| 2288 | | .minor_linker_version = 0, |
| 2289 | | .size_of_code = size_of_code, |
| 2290 | | .size_of_initialized_data = size_of_initialized_data, |
| 2291 | | .size_of_uninitialized_data = size_of_uninitialized_data, |
| 2292 | | .address_of_entry_point = coff.entry_addr orelse 0, |
| 2293 | | .base_of_code = base_of_code, |
| 2294 | | .base_of_data = base_of_data, |
| 2295 | | .image_base = @intCast(coff.image_base), |
| 2296 | | .section_alignment = coff.page_size, |
| 2297 | | .file_alignment = default_file_alignment, |
| 2298 | | .major_operating_system_version = 6, |
| 2299 | | .minor_operating_system_version = 0, |
| 2300 | | .major_image_version = 0, |
| 2301 | | .minor_image_version = 0, |
| 2302 | | .major_subsystem_version = @intCast(coff.major_subsystem_version), |
| 2303 | | .minor_subsystem_version = @intCast(coff.minor_subsystem_version), |
| 2304 | | .win32_version_value = 0, |
| 2305 | | .size_of_image = size_of_image, |
| 2306 | | .size_of_headers = size_of_headers, |
| 2307 | | .checksum = 0, |
| 2308 | | .subsystem = subsystem, |
| 2309 | | .dll_flags = dll_flags, |
| 2310 | | .size_of_stack_reserve = default_size_of_stack_reserve, |
| 2311 | | .size_of_stack_commit = default_size_of_stack_commit, |
| 2312 | | .size_of_heap_reserve = default_size_of_heap_reserve, |
| 2313 | | .size_of_heap_commit = default_size_of_heap_commit, |
| 2314 | | .loader_flags = 0, |
| 2315 | | .number_of_rva_and_sizes = @intCast(coff.data_directories.len), |
| 2316 | | }; |
| 2317 | | writer.writeAll(mem.asBytes(&opt_header)) catch unreachable; |
| 2318 | | }, |
| 2319 | | .p64 => { |
| 2320 | | var opt_header = coff_util.OptionalHeaderPE64{ |
| 2321 | | .magic = .@"PE32+", |
| 2322 | | .major_linker_version = 0, |
| 2323 | | .minor_linker_version = 0, |
| 2324 | | .size_of_code = size_of_code, |
| 2325 | | .size_of_initialized_data = size_of_initialized_data, |
| 2326 | | .size_of_uninitialized_data = size_of_uninitialized_data, |
| 2327 | | .address_of_entry_point = coff.entry_addr orelse 0, |
| 2328 | | .base_of_code = base_of_code, |
| 2329 | | .image_base = coff.image_base, |
| 2330 | | .section_alignment = coff.page_size, |
| 2331 | | .file_alignment = default_file_alignment, |
| 2332 | | .major_operating_system_version = 6, |
| 2333 | | .minor_operating_system_version = 0, |
| 2334 | | .major_image_version = 0, |
| 2335 | | .minor_image_version = 0, |
| 2336 | | .major_subsystem_version = coff.major_subsystem_version, |
| 2337 | | .minor_subsystem_version = coff.minor_subsystem_version, |
| 2338 | | .win32_version_value = 0, |
| 2339 | | .size_of_image = size_of_image, |
| 2340 | | .size_of_headers = size_of_headers, |
| 2341 | | .checksum = 0, |
| 2342 | | .subsystem = subsystem, |
| 2343 | | .dll_flags = dll_flags, |
| 2344 | | .size_of_stack_reserve = default_size_of_stack_reserve, |
| 2345 | | .size_of_stack_commit = default_size_of_stack_commit, |
| 2346 | | .size_of_heap_reserve = default_size_of_heap_reserve, |
| 2347 | | .size_of_heap_commit = default_size_of_heap_commit, |
| 2348 | | .loader_flags = 0, |
| 2349 | | .number_of_rva_and_sizes = @intCast(coff.data_directories.len), |
| 2350 | | }; |
| 2351 | | writer.writeAll(mem.asBytes(&opt_header)) catch unreachable; |
| 2352 | | }, |
| 2353 | | } |
| 2354 | | |
| 2355 | | try coff.pwriteAll(buffer.written(), 0); |
| 2356 | | } |
| 2357 | | |
| 2358 | | pub fn padToIdeal(actual_size: anytype) @TypeOf(actual_size) { |
| 2359 | | return actual_size +| (actual_size / ideal_factor); |
| 2360 | | } |
| 2361 | | |
| 2362 | | fn detectAllocCollision(coff: *Coff, start: u32, size: u32) ?u32 { |
| 2363 | | const headers_size = @max(coff.getSizeOfHeaders(), coff.page_size); |
| 2364 | | if (start < headers_size) |
| 2365 | | return headers_size; |
| 2366 | | |
| 2367 | | const end = start + padToIdeal(size); |
| 2368 | | |
| 2369 | | if (coff.strtab_offset) |off| { |
| 2370 | | const tight_size = @as(u32, @intCast(coff.strtab.buffer.items.len)); |
| 2371 | | const increased_size = padToIdeal(tight_size); |
| 2372 | | const test_end = off + increased_size; |
| 2373 | | if (end > off and start < test_end) { |
| 2374 | | return test_end; |
| 2375 | | } |
| 2376 | | } |
| 2377 | | |
| 2378 | | for (coff.sections.items(.header)) |header| { |
| 2379 | | const tight_size = header.size_of_raw_data; |
| 2380 | | const increased_size = padToIdeal(tight_size); |
| 2381 | | const test_end = header.pointer_to_raw_data + increased_size; |
| 2382 | | if (end > header.pointer_to_raw_data and start < test_end) { |
| 2383 | | return test_end; |
| 2384 | | } |
| 2385 | | } |
| 2386 | | |
| 2387 | | return null; |
| 2388 | | } |
| 2389 | | |
| 2390 | | fn allocatedSize(coff: *Coff, start: u32) u32 { |
| 2391 | | if (start == 0) |
| 2392 | | return 0; |
| 2393 | | var min_pos: u32 = std.math.maxInt(u32); |
| 2394 | | if (coff.strtab_offset) |off| { |
| 2395 | | if (off > start and off < min_pos) min_pos = off; |
| 2396 | | } |
| 2397 | | for (coff.sections.items(.header)) |header| { |
| 2398 | | if (header.pointer_to_raw_data <= start) continue; |
| 2399 | | if (header.pointer_to_raw_data < min_pos) min_pos = header.pointer_to_raw_data; |
| 2400 | | } |
| 2401 | | return min_pos - start; |
| 2402 | | } |
| 2403 | | |
| 2404 | | fn findFreeSpace(coff: *Coff, object_size: u32, min_alignment: u32) u32 { |
| 2405 | | var start: u32 = 0; |
| 2406 | | while (coff.detectAllocCollision(start, object_size)) |item_end| { |
| 2407 | | start = mem.alignForward(u32, item_end, min_alignment); |
| 2408 | | } |
| 2409 | | return start; |
| 2410 | | } |
| 2411 | | |
| 2412 | | fn allocatedVirtualSize(coff: *Coff, start: u32) u32 { |
| 2413 | | if (start == 0) |
| 2414 | | return 0; |
| 2415 | | var min_pos: u32 = std.math.maxInt(u32); |
| 2416 | | for (coff.sections.items(.header)) |header| { |
| 2417 | | if (header.virtual_address <= start) continue; |
| 2418 | | if (header.virtual_address < min_pos) min_pos = header.virtual_address; |
| 2419 | | } |
| 2420 | | return min_pos - start; |
| 2421 | | } |
| 2422 | | |
| 2423 | | fn getSizeOfHeaders(coff: Coff) u32 { |
| 2424 | | const msdos_hdr_size = msdos_stub.len + 4; |
| 2425 | | return @as(u32, @intCast(msdos_hdr_size + @sizeOf(coff_util.Header) + coff.getOptionalHeaderSize() + |
| 2426 | | coff.getDataDirectoryHeadersSize() + coff.getSectionHeadersSize())); |
| 2427 | | } |
| 2428 | | |
| 2429 | | fn getOptionalHeaderSize(coff: Coff) u32 { |
| 2430 | | return switch (coff.ptr_width) { |
| 2431 | | .p32 => @as(u32, @intCast(@sizeOf(coff_util.OptionalHeaderPE32))), |
| 2432 | | .p64 => @as(u32, @intCast(@sizeOf(coff_util.OptionalHeaderPE64))), |
| 2433 | | }; |
| 2434 | | } |
| 2435 | | |
| 2436 | | fn getDataDirectoryHeadersSize(coff: Coff) u32 { |
| 2437 | | return @as(u32, @intCast(coff.data_directories.len * @sizeOf(coff_util.ImageDataDirectory))); |
| 2438 | | } |
| 2439 | | |
| 2440 | | fn getSectionHeadersSize(coff: Coff) u32 { |
| 2441 | | return @as(u32, @intCast(coff.sections.slice().len * @sizeOf(coff_util.SectionHeader))); |
| 2442 | | } |
| 2443 | | |
| 2444 | | fn getDataDirectoryHeadersOffset(coff: Coff) u32 { |
| 2445 | | const msdos_hdr_size = msdos_stub.len + 4; |
| 2446 | | return @as(u32, @intCast(msdos_hdr_size + @sizeOf(coff_util.Header) + coff.getOptionalHeaderSize())); |
| 2447 | | } |
| 2448 | | |
| 2449 | | fn getSectionHeadersOffset(coff: Coff) u32 { |
| 2450 | | return coff.getDataDirectoryHeadersOffset() + coff.getDataDirectoryHeadersSize(); |
| 2451 | | } |
| 2452 | | |
| 2453 | | fn getSizeOfImage(coff: Coff) u32 { |
| 2454 | | var image_size: u32 = mem.alignForward(u32, coff.getSizeOfHeaders(), coff.page_size); |
| 2455 | | for (coff.sections.items(.header)) |header| { |
| 2456 | | image_size += mem.alignForward(u32, header.virtual_size, coff.page_size); |
| 2457 | | } |
| 2458 | | return image_size; |
| 2459 | | } |
| 2460 | | |
| 2461 | | /// Returns symbol location corresponding to the set entrypoint (if any). |
| 2462 | | pub fn getEntryPoint(coff: Coff) ?SymbolWithLoc { |
| 2463 | | const comp = coff.base.comp; |
| 2464 | | |
| 2465 | | // TODO This is incomplete. |
| 2466 | | // The entry symbol name depends on the subsystem as well as the set of |
| 2467 | | // public symbol names from linked objects. |
| 2468 | | // See LinkerDriver::findDefaultEntry from the LLD project for the flow chart. |
| 2469 | | const entry_name = switch (coff.entry) { |
| 2470 | | .disabled => return null, |
| 2471 | | .default => switch (comp.config.output_mode) { |
| 2472 | | .Exe => "wWinMainCRTStartup", |
| 2473 | | .Obj, .Lib => return null, |
| 2474 | | }, |
| 2475 | | .enabled => "wWinMainCRTStartup", |
| 2476 | | .named => |name| name, |
| 2477 | | }; |
| 2478 | | const global_index = coff.resolver.get(entry_name) orelse return null; |
| 2479 | | return coff.globals.items[global_index]; |
| 2480 | | } |
| 2481 | | |
| 2482 | | /// Returns pointer-to-symbol described by `sym_loc` descriptor. |
| 2483 | | pub fn getSymbolPtr(coff: *Coff, sym_loc: SymbolWithLoc) *coff_util.Symbol { |
| 2484 | | assert(sym_loc.file == null); // TODO linking object files |
| 2485 | | return &coff.locals.items[sym_loc.sym_index]; |
| 2486 | | } |
| 2487 | | |
| 2488 | | /// Returns symbol described by `sym_loc` descriptor. |
| 2489 | | pub fn getSymbol(coff: *const Coff, sym_loc: SymbolWithLoc) *const coff_util.Symbol { |
| 2490 | | assert(sym_loc.file == null); // TODO linking object files |
| 2491 | | return &coff.locals.items[sym_loc.sym_index]; |
| 2492 | | } |
| 2493 | | |
| 2494 | | /// Returns name of the symbol described by `sym_loc` descriptor. |
| 2495 | | pub fn getSymbolName(coff: *const Coff, sym_loc: SymbolWithLoc) []const u8 { |
| 2496 | | assert(sym_loc.file == null); // TODO linking object files |
| 2497 | | const sym = coff.getSymbol(sym_loc); |
| 2498 | | const offset = sym.getNameOffset() orelse return sym.getName().?; |
| 2499 | | return coff.strtab.get(offset).?; |
| 2500 | | } |
| 2501 | | |
| 2502 | | /// Returns pointer to the global entry for `name` if one exists. |
| 2503 | | pub fn getGlobalPtr(coff: *Coff, name: []const u8) ?*SymbolWithLoc { |
| 2504 | | const global_index = coff.resolver.get(name) orelse return null; |
| 2505 | | return &coff.globals.items[global_index]; |
| 2506 | | } |
| 2507 | | |
| 2508 | | /// Returns the global entry for `name` if one exists. |
| 2509 | | pub fn getGlobal(coff: *const Coff, name: []const u8) ?SymbolWithLoc { |
| 2510 | | const global_index = coff.resolver.get(name) orelse return null; |
| 2511 | | return coff.globals.items[global_index]; |
| 2512 | | } |
| 2513 | | |
| 2514 | | /// Returns the index of the global entry for `name` if one exists. |
| 2515 | | pub fn getGlobalIndex(coff: *const Coff, name: []const u8) ?u32 { |
| 2516 | | return coff.resolver.get(name); |
| 2517 | | } |
| 2518 | | |
| 2519 | | /// Returns global entry at `index`. |
| 2520 | | pub fn getGlobalByIndex(coff: *const Coff, index: u32) SymbolWithLoc { |
| 2521 | | assert(index < coff.globals.items.len); |
| 2522 | | return coff.globals.items[index]; |
| 2523 | | } |
| 2524 | | |
| 2525 | | const GetOrPutGlobalPtrResult = struct { |
| 2526 | | found_existing: bool, |
| 2527 | | value_ptr: *SymbolWithLoc, |
| 2528 | | }; |
| 2529 | | |
| 2530 | | /// Return pointer to the global entry for `name` if one exists. |
| 2531 | | /// Puts a new global entry for `name` if one doesn't exist, and |
| 2532 | | /// returns a pointer to it. |
| 2533 | | pub fn getOrPutGlobalPtr(coff: *Coff, name: []const u8) !GetOrPutGlobalPtrResult { |
| 2534 | | if (coff.getGlobalPtr(name)) |ptr| { |
| 2535 | | return GetOrPutGlobalPtrResult{ .found_existing = true, .value_ptr = ptr }; |
| 2536 | | } |
| 2537 | | const gpa = coff.base.comp.gpa; |
| 2538 | | const global_index = try coff.allocateGlobal(); |
| 2539 | | const global_name = try gpa.dupe(u8, name); |
| 2540 | | _ = try coff.resolver.put(gpa, global_name, global_index); |
| 2541 | | const ptr = &coff.globals.items[global_index]; |
| 2542 | | return GetOrPutGlobalPtrResult{ .found_existing = false, .value_ptr = ptr }; |
| 2543 | | } |
| 2544 | | |
| 2545 | | pub fn getAtom(coff: *const Coff, atom_index: Atom.Index) Atom { |
| 2546 | | assert(atom_index < coff.atoms.items.len); |
| 2547 | | return coff.atoms.items[atom_index]; |
| 2548 | | } |
| 2549 | | |
| 2550 | | pub fn getAtomPtr(coff: *Coff, atom_index: Atom.Index) *Atom { |
| 2551 | | assert(atom_index < coff.atoms.items.len); |
| 2552 | | return &coff.atoms.items[atom_index]; |
| 2553 | | } |
| 2554 | | |
| 2555 | | /// Returns atom if there is an atom referenced by the symbol described by `sym_loc` descriptor. |
| 2556 | | /// Returns null on failure. |
| 2557 | | pub fn getAtomIndexForSymbol(coff: *const Coff, sym_loc: SymbolWithLoc) ?Atom.Index { |
| 2558 | | assert(sym_loc.file == null); // TODO linking with object files |
| 2559 | | return coff.atom_by_index_table.get(sym_loc.sym_index); |
| 2560 | | } |
| 2561 | | |
| 2562 | | fn setSectionName(coff: *Coff, header: *coff_util.SectionHeader, name: []const u8) !void { |
| 2563 | | if (name.len <= 8) { |
| 2564 | | @memcpy(header.name[0..name.len], name); |
| 2565 | | @memset(header.name[name.len..], 0); |
| 2566 | | return; |
| 2567 | | } |
| 2568 | | const gpa = coff.base.comp.gpa; |
| 2569 | | const offset = try coff.strtab.insert(gpa, name); |
| 2570 | | const name_offset = fmt.bufPrint(&header.name, "/{d}", .{offset}) catch unreachable; |
| 2571 | | @memset(header.name[name_offset.len..], 0); |
| 2572 | | } |
| 2573 | | |
| 2574 | | fn getSectionName(coff: *const Coff, header: *const coff_util.SectionHeader) []const u8 { |
| 2575 | | if (header.getName()) |name| { |
| 2576 | | return name; |
| 2577 | | } |
| 2578 | | const offset = header.getNameOffset().?; |
| 2579 | | return coff.strtab.get(offset).?; |
| 2580 | | } |
| 2581 | | |
| 2582 | | fn setSymbolName(coff: *Coff, symbol: *coff_util.Symbol, name: []const u8) !void { |
| 2583 | | if (name.len <= 8) { |
| 2584 | | @memcpy(symbol.name[0..name.len], name); |
| 2585 | | @memset(symbol.name[name.len..], 0); |
| 2586 | | return; |
| 2587 | | } |
| 2588 | | const gpa = coff.base.comp.gpa; |
| 2589 | | const offset = try coff.strtab.insert(gpa, name); |
| 2590 | | @memset(symbol.name[0..4], 0); |
| 2591 | | mem.writeInt(u32, symbol.name[4..8], offset, .little); |
| 2592 | | } |
| 2593 | | |
| 2594 | | fn logSymAttributes(sym: *const coff_util.Symbol, buf: *[4]u8) []const u8 { |
| 2595 | | @memset(buf[0..4], '_'); |
| 2596 | | switch (sym.section_number) { |
| 2597 | | .UNDEFINED => { |
| 2598 | | buf[3] = 'u'; |
| 2599 | | switch (sym.storage_class) { |
| 2600 | | .EXTERNAL => buf[1] = 'e', |
| 2601 | | .WEAK_EXTERNAL => buf[1] = 'w', |
| 2602 | | .NULL => {}, |
| 2603 | | else => unreachable, |
| 2604 | | } |
| 2605 | | }, |
| 2606 | | .ABSOLUTE => unreachable, // handle ABSOLUTE |
| 2607 | | .DEBUG => unreachable, |
| 2608 | | else => { |
| 2609 | | buf[0] = 's'; |
| 2610 | | switch (sym.storage_class) { |
| 2611 | | .EXTERNAL => buf[1] = 'e', |
| 2612 | | .WEAK_EXTERNAL => buf[1] = 'w', |
| 2613 | | .NULL => {}, |
| 2614 | | else => unreachable, |
| 2615 | | } |
| 2616 | | }, |
| 2617 | | } |
| 2618 | | return buf[0..]; |
| 2619 | | } |
| 2620 | | |
| 2621 | | fn logSymtab(coff: *Coff) void { |
| 2622 | | var buf: [4]u8 = undefined; |
| 2623 | | |
| 2624 | | log.debug("symtab:", .{}); |
| 2625 | | log.debug(" object(null)", .{}); |
| 2626 | | for (coff.locals.items, 0..) |*sym, sym_id| { |
| 2627 | | const where = if (sym.section_number == .UNDEFINED) "ord" else "sect"; |
| 2628 | | const def_index: u16 = switch (sym.section_number) { |
| 2629 | | .UNDEFINED => 0, // TODO |
| 2630 | | .ABSOLUTE => unreachable, // TODO |
| 2631 | | .DEBUG => unreachable, // TODO |
| 2632 | | else => @intFromEnum(sym.section_number), |
| 2633 | | }; |
| 2634 | | log.debug(" %{d}: {s} @{x} in {s}({d}), {s}", .{ |
| 2635 | | sym_id, |
| 2636 | | coff.getSymbolName(.{ .sym_index = @as(u32, @intCast(sym_id)), .file = null }), |
| 2637 | | sym.value, |
| 2638 | | where, |
| 2639 | | def_index, |
| 2640 | | logSymAttributes(sym, &buf), |
| 2641 | | }); |
| 2642 | | } |
| 2643 | | |
| 2644 | | log.debug("globals table:", .{}); |
| 2645 | | for (coff.globals.items) |sym_loc| { |
| 2646 | | const sym_name = coff.getSymbolName(sym_loc); |
| 2647 | | log.debug(" {s} => %{d} in object({?d})", .{ sym_name, sym_loc.sym_index, sym_loc.file }); |
| 2648 | | } |
| 2649 | | |
| 2650 | | log.debug("GOT entries:", .{}); |
| 2651 | | log.debug("{f}", .{coff.got_table}); |
| 2652 | | } |
| 2653 | | |
| 2654 | | fn logSections(coff: *Coff) void { |
| 2655 | | log.debug("sections:", .{}); |
| 2656 | | for (coff.sections.items(.header)) |*header| { |
| 2657 | | log.debug(" {s}: VM({x}, {x}) FILE({x}, {x})", .{ |
| 2658 | | coff.getSectionName(header), |
| 2659 | | header.virtual_address, |
| 2660 | | header.virtual_address + header.virtual_size, |
| 2661 | | header.pointer_to_raw_data, |
| 2662 | | header.pointer_to_raw_data + header.size_of_raw_data, |
| 2663 | | }); |
| 2664 | | } |
| 2665 | | } |
| 2666 | | |
| 2667 | | fn logImportTables(coff: *const Coff) void { |
| 2668 | | log.debug("import tables:", .{}); |
| 2669 | | for (coff.import_tables.keys(), 0..) |off, i| { |
| 2670 | | const itable = coff.import_tables.values()[i]; |
| 2671 | | log.debug("{f}", .{itable.fmtDebug(.{ |
| 2672 | | .coff = coff, |
| 2673 | | .index = i, |
| 2674 | | .name_off = off, |
| 2675 | | })}); |
| 2676 | | } |
| 2677 | | } |
| 2678 | | |
| 2679 | | pub const Atom = struct { |
| 2680 | | /// Each decl always gets a local symbol with the fully qualified name. |
| 2681 | | /// The vaddr and size are found here directly. |
| 2682 | | /// The file offset is found by computing the vaddr offset from the section vaddr |
| 2683 | | /// the symbol references, and adding that to the file offset of the section. |
| 2684 | | /// If this field is 0, it means the codegen size = 0 and there is no symbol or |
| 2685 | | /// offset table entry. |
| 2686 | | sym_index: u32, |
| 2687 | | |
| 2688 | | /// null means symbol defined by Zig source. |
| 2689 | | file: ?u32, |
| 2690 | | |
| 2691 | | /// Size of the atom |
| 2692 | | size: u32, |
| 2693 | | |
| 2694 | | /// Points to the previous and next neighbors, based on the `text_offset`. |
| 2695 | | /// This can be used to find, for example, the capacity of this `Atom`. |
| 2696 | | prev_index: ?Index, |
| 2697 | | next_index: ?Index, |
| 2698 | | |
| 2699 | | const Index = u32; |
| 2700 | | |
| 2701 | | pub fn getSymbolIndex(atom: Atom) ?u32 { |
| 2702 | | if (atom.sym_index == 0) return null; |
| 2703 | | return atom.sym_index; |
| 2704 | | } |
| 2705 | | |
| 2706 | | /// Returns symbol referencing this atom. |
| 2707 | | fn getSymbol(atom: Atom, coff: *const Coff) *const coff_util.Symbol { |
| 2708 | | const sym_index = atom.getSymbolIndex().?; |
| 2709 | | return coff.getSymbol(.{ |
| 2710 | | .sym_index = sym_index, |
| 2711 | | .file = atom.file, |
| 2712 | | }); |
| 2713 | | } |
| 2714 | | |
| 2715 | | /// Returns pointer-to-symbol referencing this atom. |
| 2716 | | fn getSymbolPtr(atom: Atom, coff: *Coff) *coff_util.Symbol { |
| 2717 | | const sym_index = atom.getSymbolIndex().?; |
| 2718 | | return coff.getSymbolPtr(.{ |
| 2719 | | .sym_index = sym_index, |
| 2720 | | .file = atom.file, |
| 2721 | | }); |
| 2722 | | } |
| 2723 | | |
| 2724 | | fn getSymbolWithLoc(atom: Atom) SymbolWithLoc { |
| 2725 | | const sym_index = atom.getSymbolIndex().?; |
| 2726 | | return .{ .sym_index = sym_index, .file = atom.file }; |
| 2727 | | } |
| 2728 | | |
| 2729 | | /// Returns the name of this atom. |
| 2730 | | fn getName(atom: Atom, coff: *const Coff) []const u8 { |
| 2731 | | const sym_index = atom.getSymbolIndex().?; |
| 2732 | | return coff.getSymbolName(.{ |
| 2733 | | .sym_index = sym_index, |
| 2734 | | .file = atom.file, |
| 2735 | | }); |
| 2736 | | } |
| 2737 | | |
| 2738 | | /// Returns how much room there is to grow in virtual address space. |
| 2739 | | fn capacity(atom: Atom, coff: *const Coff) u32 { |
| 2740 | | const atom_sym = atom.getSymbol(coff); |
| 2741 | | if (atom.next_index) |next_index| { |
| 2742 | | const next = coff.getAtom(next_index); |
| 2743 | | const next_sym = next.getSymbol(coff); |
| 2744 | | return next_sym.value - atom_sym.value; |
| 2745 | | } else { |
| 2746 | | // We are the last atom. |
| 2747 | | // The capacity is limited only by virtual address space. |
| 2748 | | return std.math.maxInt(u32) - atom_sym.value; |
| 2749 | | } |
| 2750 | | } |
| 2751 | | |
| 2752 | | fn freeListEligible(atom: Atom, coff: *const Coff) bool { |
| 2753 | | // No need to keep a free list node for the last atom. |
| 2754 | | const next_index = atom.next_index orelse return false; |
| 2755 | | const next = coff.getAtom(next_index); |
| 2756 | | const atom_sym = atom.getSymbol(coff); |
| 2757 | | const next_sym = next.getSymbol(coff); |
| 2758 | | const cap = next_sym.value - atom_sym.value; |
| 2759 | | const ideal_cap = padToIdeal(atom.size); |
| 2760 | | if (cap <= ideal_cap) return false; |
| 2761 | | const surplus = cap - ideal_cap; |
| 2762 | | return surplus >= min_text_capacity; |
| 2763 | | } |
| 2764 | | }; |
| 2765 | | |
| 2766 | | pub const Relocation = struct { |
| 2767 | | type: enum { |
| 2768 | | // x86, x86_64 |
| 2769 | | /// RIP-relative displacement to a GOT pointer |
| 2770 | | got, |
| 2771 | | /// RIP-relative displacement to an import pointer |
| 2772 | | import, |
| 2773 | | |
| 2774 | | // aarch64 |
| 2775 | | /// PC-relative distance to target page in GOT section |
| 2776 | | got_page, |
| 2777 | | /// Offset to a GOT pointer relative to the start of a page in GOT section |
| 2778 | | got_pageoff, |
| 2779 | | /// PC-relative distance to target page in a section (e.g., .rdata) |
| 2780 | | page, |
| 2781 | | /// Offset to a pointer relative to the start of a page in a section (e.g., .rdata) |
| 2782 | | pageoff, |
| 2783 | | /// PC-relative distance to target page in a import section |
| 2784 | | import_page, |
| 2785 | | /// Offset to a pointer relative to the start of a page in an import section (e.g., .rdata) |
| 2786 | | import_pageoff, |
| 2787 | | |
| 2788 | | // common |
| 2789 | | /// Absolute pointer value |
| 2790 | | direct, |
| 2791 | | }, |
| 2792 | | target: SymbolWithLoc, |
| 2793 | | offset: u32, |
| 2794 | | addend: u32, |
| 2795 | | pcrel: bool, |
| 2796 | | length: u2, |
| 2797 | | dirty: bool = true, |
| 2798 | | |
| 2799 | | /// Returns true if and only if the reloc can be resolved. |
| 2800 | | fn isResolvable(reloc: Relocation, coff: *Coff) bool { |
| 2801 | | _ = reloc.getTargetAddress(coff) orelse return false; |
| 2802 | | return true; |
| 2803 | | } |
| 2804 | | |
| 2805 | | fn isGotIndirection(reloc: Relocation) bool { |
| 2806 | | return switch (reloc.type) { |
| 2807 | | .got, .got_page, .got_pageoff => true, |
| 2808 | | else => false, |
| 2809 | | }; |
| 2810 | | } |
| 2811 | | |
| 2812 | | /// Returns address of the target if any. |
| 2813 | | fn getTargetAddress(reloc: Relocation, coff: *const Coff) ?u32 { |
| 2814 | | switch (reloc.type) { |
| 2815 | | .got, .got_page, .got_pageoff => { |
| 2816 | | const got_index = coff.got_table.lookup.get(reloc.target) orelse return null; |
| 2817 | | const header = coff.sections.items(.header)[coff.got_section_index.?]; |
| 2818 | | return header.virtual_address + got_index * coff.ptr_width.size(); |
| 2819 | | }, |
| 2820 | | .import, .import_page, .import_pageoff => { |
| 2821 | | const sym = coff.getSymbol(reloc.target); |
| 2822 | | const index = coff.import_tables.getIndex(sym.value) orelse return null; |
| 2823 | | const itab = coff.import_tables.values()[index]; |
| 2824 | | return itab.getImportAddress(reloc.target, .{ |
| 2825 | | .coff = coff, |
| 2826 | | .index = index, |
| 2827 | | .name_off = sym.value, |
| 2828 | | }); |
| 2829 | | }, |
| 2830 | | else => { |
| 2831 | | const target_atom_index = coff.getAtomIndexForSymbol(reloc.target) orelse return null; |
| 2832 | | const target_atom = coff.getAtom(target_atom_index); |
| 2833 | | return target_atom.getSymbol(coff).value; |
| 2834 | | }, |
| 2835 | | } |
| 2836 | | } |
| 2837 | | |
| 2838 | | fn resolve(reloc: Relocation, atom_index: Atom.Index, code: []u8, image_base: u64, coff: *Coff) void { |
| 2839 | | const atom = coff.getAtom(atom_index); |
| 2840 | | const source_sym = atom.getSymbol(coff); |
| 2841 | | const source_vaddr = source_sym.value + reloc.offset; |
| 2842 | | |
| 2843 | | const target_vaddr = reloc.getTargetAddress(coff).?; // Oops, you didn't check if the relocation can be resolved with isResolvable(). |
| 2844 | | const target_vaddr_with_addend = target_vaddr + reloc.addend; |
| 2845 | | |
| 2846 | | log.debug(" ({x}: [() => 0x{x} ({s})) ({s}) ", .{ |
| 2847 | | source_vaddr, |
| 2848 | | target_vaddr_with_addend, |
| 2849 | | coff.getSymbolName(reloc.target), |
| 2850 | | @tagName(reloc.type), |
| 2851 | | }); |
| 2852 | | |
| 2853 | | const ctx: Context = .{ |
| 2854 | | .source_vaddr = source_vaddr, |
| 2855 | | .target_vaddr = target_vaddr_with_addend, |
| 2856 | | .image_base = image_base, |
| 2857 | | .code = code, |
| 2858 | | .ptr_width = coff.ptr_width, |
| 2859 | | }; |
| 2860 | | |
| 2861 | | const target = &coff.base.comp.root_mod.resolved_target.result; |
| 2862 | | switch (target.cpu.arch) { |
| 2863 | | .aarch64 => reloc.resolveAarch64(ctx), |
| 2864 | | .x86, .x86_64 => reloc.resolveX86(ctx), |
| 2865 | | else => unreachable, // unhandled target architecture |
| 2866 | | } |
| 2867 | | } |
| 2868 | | |
| 2869 | | const Context = struct { |
| 2870 | | source_vaddr: u32, |
| 2871 | | target_vaddr: u32, |
| 2872 | | image_base: u64, |
| 2873 | | code: []u8, |
| 2874 | | ptr_width: PtrWidth, |
| 2875 | | }; |
| 2876 | | |
| 2877 | | fn resolveAarch64(reloc: Relocation, ctx: Context) void { |
| 2878 | | const Instruction = aarch64_util.encoding.Instruction; |
| 2879 | | var buffer = ctx.code[reloc.offset..]; |
| 2880 | | switch (reloc.type) { |
| 2881 | | .got_page, .import_page, .page => { |
| 2882 | | const source_page = @as(i32, @intCast(ctx.source_vaddr >> 12)); |
| 2883 | | const target_page = @as(i32, @intCast(ctx.target_vaddr >> 12)); |
| 2884 | | const pages: i21 = @intCast(target_page - source_page); |
| 2885 | | var inst: Instruction = .read(buffer[0..Instruction.size]); |
| 2886 | | inst.data_processing_immediate.pc_relative_addressing.group.immhi = @intCast(pages >> 2); |
| 2887 | | inst.data_processing_immediate.pc_relative_addressing.group.immlo = @truncate(@as(u21, @bitCast(pages))); |
| 2888 | | inst.write(buffer[0..Instruction.size]); |
| 2889 | | }, |
| 2890 | | .got_pageoff, .import_pageoff, .pageoff => { |
| 2891 | | assert(!reloc.pcrel); |
| 2892 | | |
| 2893 | | const narrowed: u12 = @truncate(@as(u64, @intCast(ctx.target_vaddr))); |
| 2894 | | var inst: Instruction = .read(buffer[0..Instruction.size]); |
| 2895 | | switch (inst.decode()) { |
| 2896 | | else => unreachable, |
| 2897 | | .data_processing_immediate => inst.data_processing_immediate.add_subtract_immediate.group.imm12 = narrowed, |
| 2898 | | .load_store => |load_store| inst.load_store.register_unsigned_immediate.group.imm12 = |
| 2899 | | switch (load_store.register_unsigned_immediate.decode()) { |
| 2900 | | .integer => |integer| @shrExact(narrowed, @intFromEnum(integer.group.size)), |
| 2901 | | .vector => |vector| @shrExact(narrowed, @intFromEnum(vector.group.opc1.decode(vector.group.size))), |
| 2902 | | }, |
| 2903 | | } |
| 2904 | | inst.write(buffer[0..Instruction.size]); |
| 2905 | | }, |
| 2906 | | .direct => { |
| 2907 | | assert(!reloc.pcrel); |
| 2908 | | switch (reloc.length) { |
| 2909 | | 2 => mem.writeInt( |
| 2910 | | u32, |
| 2911 | | buffer[0..4], |
| 2912 | | @as(u32, @truncate(ctx.target_vaddr + ctx.image_base)), |
| 2913 | | .little, |
| 2914 | | ), |
| 2915 | | 3 => mem.writeInt(u64, buffer[0..8], ctx.target_vaddr + ctx.image_base, .little), |
| 2916 | | else => unreachable, |
| 2917 | | } |
| 2918 | | }, |
| 2919 | | |
| 2920 | | .got => unreachable, |
| 2921 | | .import => unreachable, |
| 2922 | | } |
| 2923 | | } |
| 2924 | | |
| 2925 | | fn resolveX86(reloc: Relocation, ctx: Context) void { |
| 2926 | | var buffer = ctx.code[reloc.offset..]; |
| 2927 | | switch (reloc.type) { |
| 2928 | | .got_page => unreachable, |
| 2929 | | .got_pageoff => unreachable, |
| 2930 | | .page => unreachable, |
| 2931 | | .pageoff => unreachable, |
| 2932 | | .import_page => unreachable, |
| 2933 | | .import_pageoff => unreachable, |
| 2934 | | |
| 2935 | | .got, .import => { |
| 2936 | | assert(reloc.pcrel); |
| 2937 | | const disp = @as(i32, @intCast(ctx.target_vaddr)) - @as(i32, @intCast(ctx.source_vaddr)) - 4; |
| 2938 | | mem.writeInt(i32, buffer[0..4], disp, .little); |
| 2939 | | }, |
| 2940 | | .direct => { |
| 2941 | | if (reloc.pcrel) { |
| 2942 | | const disp = @as(i32, @intCast(ctx.target_vaddr)) - @as(i32, @intCast(ctx.source_vaddr)) - 4; |
| 2943 | | mem.writeInt(i32, buffer[0..4], disp, .little); |
| 2944 | | } else switch (ctx.ptr_width) { |
| 2945 | | .p32 => mem.writeInt(u32, buffer[0..4], @as(u32, @intCast(ctx.target_vaddr + ctx.image_base)), .little), |
| 2946 | | .p64 => switch (reloc.length) { |
| 2947 | | 2 => mem.writeInt(u32, buffer[0..4], @as(u32, @truncate(ctx.target_vaddr + ctx.image_base)), .little), |
| 2948 | | 3 => mem.writeInt(u64, buffer[0..8], ctx.target_vaddr + ctx.image_base, .little), |
| 2949 | | else => unreachable, |
| 2950 | | }, |
| 2951 | | } |
| 2952 | | }, |
| 2953 | | } |
| 2954 | | } |
| 2955 | | }; |
| 2956 | | |
| 2957 | | pub fn addRelocation(coff: *Coff, atom_index: Atom.Index, reloc: Relocation) !void { |
| 2958 | | const comp = coff.base.comp; |
| 2959 | | const gpa = comp.gpa; |
| 2960 | | log.debug(" (adding reloc of type {s} to target %{d})", .{ @tagName(reloc.type), reloc.target.sym_index }); |
| 2961 | | const gop = try coff.relocs.getOrPut(gpa, atom_index); |
| 2962 | | if (!gop.found_existing) { |
| 2963 | | gop.value_ptr.* = .{}; |
| 2964 | | } |
| 2965 | | try gop.value_ptr.append(gpa, reloc); |
| 2966 | | } |
| 2967 | | |
| 2968 | | fn addBaseRelocation(coff: *Coff, atom_index: Atom.Index, offset: u32) !void { |
| 2969 | | const comp = coff.base.comp; |
| 2970 | | const gpa = comp.gpa; |
| 2971 | | log.debug(" (adding base relocation at offset 0x{x} in %{d})", .{ |
| 2972 | | offset, |
| 2973 | | coff.getAtom(atom_index).getSymbolIndex().?, |
| 2974 | | }); |
| 2975 | | const gop = try coff.base_relocs.getOrPut(gpa, atom_index); |
| 2976 | | if (!gop.found_existing) { |
| 2977 | | gop.value_ptr.* = .{}; |
| 2978 | | } |
| 2979 | | try gop.value_ptr.append(gpa, offset); |
| 2980 | | } |
| 2981 | | |
| 2982 | | fn freeRelocations(coff: *Coff, atom_index: Atom.Index) void { |
| 2983 | | const comp = coff.base.comp; |
| 2984 | | const gpa = comp.gpa; |
| 2985 | | var removed_relocs = coff.relocs.fetchOrderedRemove(atom_index); |
| 2986 | | if (removed_relocs) |*relocs| relocs.value.deinit(gpa); |
| 2987 | | var removed_base_relocs = coff.base_relocs.fetchOrderedRemove(atom_index); |
| 2988 | | if (removed_base_relocs) |*base_relocs| base_relocs.value.deinit(gpa); |
| 2989 | | } |
| 2990 | | |
| 2991 | | /// Represents an import table in the .idata section where each contained pointer |
| 2992 | | /// is to a symbol from the same DLL. |
| 2993 | | /// |
| 2994 | | /// The layout of .idata section is as follows: |
| 2995 | | /// |
| 2996 | | /// --- ADDR1 : IAT (all import tables concatenated together) |
| 2997 | | /// ptr |
| 2998 | | /// ptr |
| 2999 | | /// 0 sentinel |
| 3000 | | /// ptr |
| 3001 | | /// 0 sentinel |
| 3002 | | /// --- ADDR2: headers |
| 3003 | | /// ImportDirectoryEntry header |
| 3004 | | /// ImportDirectoryEntry header |
| 3005 | | /// sentinel |
| 3006 | | /// --- ADDR2: lookup tables |
| 3007 | | /// Lookup table |
| 3008 | | /// 0 sentinel |
| 3009 | | /// Lookup table |
| 3010 | | /// 0 sentinel |
| 3011 | | /// --- ADDR3: name hint tables |
| 3012 | | /// hint-symname |
| 3013 | | /// hint-symname |
| 3014 | | /// --- ADDR4: DLL names |
| 3015 | | /// DLL#1 name |
| 3016 | | /// DLL#2 name |
| 3017 | | /// --- END |
| 3018 | | const ImportTable = struct { |
| 3019 | | entries: std.ArrayListUnmanaged(SymbolWithLoc) = .empty, |
| 3020 | | free_list: std.ArrayListUnmanaged(u32) = .empty, |
| 3021 | | lookup: std.AutoHashMapUnmanaged(SymbolWithLoc, u32) = .empty, |
| 3022 | | |
| 3023 | | fn deinit(itab: *ImportTable, allocator: Allocator) void { |
| 3024 | | itab.entries.deinit(allocator); |
| 3025 | | itab.free_list.deinit(allocator); |
| 3026 | | itab.lookup.deinit(allocator); |
| 3027 | | } |
| 3028 | | |
| 3029 | | /// Size of the import table does not include the sentinel. |
| 3030 | | fn size(itab: ImportTable) u32 { |
| 3031 | | return @as(u32, @intCast(itab.entries.items.len)) * @sizeOf(u64); |
| 3032 | | } |
| 3033 | | |
| 3034 | | fn addImport(itab: *ImportTable, allocator: Allocator, target: SymbolWithLoc) !ImportIndex { |
| 3035 | | try itab.entries.ensureUnusedCapacity(allocator, 1); |
| 3036 | | const index: u32 = blk: { |
| 3037 | | if (itab.free_list.pop()) |index| { |
| 3038 | | log.debug(" (reusing import entry index {d})", .{index}); |
| 3039 | | break :blk index; |
| 3040 | | } else { |
| 3041 | | log.debug(" (allocating import entry at index {d})", .{itab.entries.items.len}); |
| 3042 | | const index = @as(u32, @intCast(itab.entries.items.len)); |
| 3043 | | _ = itab.entries.addOneAssumeCapacity(); |
| 3044 | | break :blk index; |
| 3045 | | } |
| 3046 | | }; |
| 3047 | | itab.entries.items[index] = target; |
| 3048 | | try itab.lookup.putNoClobber(allocator, target, index); |
| 3049 | | return index; |
| 3050 | | } |
| 3051 | | |
| 3052 | | const Context = struct { |
| 3053 | | coff: *const Coff, |
| 3054 | | /// Index of this ImportTable in a global list of all tables. |
| 3055 | | /// This is required in order to calculate the base vaddr of this ImportTable. |
| 3056 | | index: usize, |
| 3057 | | /// Offset into the string interning table of the DLL this ImportTable corresponds to. |
| 3058 | | name_off: u32, |
| 3059 | | }; |
| 3060 | | |
| 3061 | | fn getBaseAddress(ctx: Context) u32 { |
| 3062 | | const header = ctx.coff.sections.items(.header)[ctx.coff.idata_section_index.?]; |
| 3063 | | var addr = header.virtual_address; |
| 3064 | | for (ctx.coff.import_tables.values(), 0..) |other_itab, i| { |
| 3065 | | if (ctx.index == i) break; |
| 3066 | | addr += @as(u32, @intCast(other_itab.entries.items.len * @sizeOf(u64))) + 8; |
| 3067 | | } |
| 3068 | | return addr; |
| 3069 | | } |
| 3070 | | |
| 3071 | | fn getImportAddress(itab: *const ImportTable, target: SymbolWithLoc, ctx: Context) ?u32 { |
| 3072 | | const index = itab.lookup.get(target) orelse return null; |
| 3073 | | const base_vaddr = getBaseAddress(ctx); |
| 3074 | | return base_vaddr + index * @sizeOf(u64); |
| 3075 | | } |
| 3076 | | |
| 3077 | | const Format = struct { |
| 3078 | | itab: ImportTable, |
| 3079 | | ctx: Context, |
| 3080 | | |
| 3081 | | fn default(f: Format, writer: *std.Io.Writer) std.Io.Writer.Error!void { |
| 3082 | | const lib_name = f.ctx.coff.temp_strtab.getAssumeExists(f.ctx.name_off); |
| 3083 | | const base_vaddr = getBaseAddress(f.ctx); |
| 3084 | | try writer.print("IAT({s}.dll) @{x}:", .{ lib_name, base_vaddr }); |
| 3085 | | for (f.itab.entries.items, 0..) |entry, i| { |
| 3086 | | try writer.print("\n {d}@{?x} => {s}", .{ |
| 3087 | | i, |
| 3088 | | f.itab.getImportAddress(entry, f.ctx), |
| 3089 | | f.ctx.coff.getSymbolName(entry), |
| 3090 | | }); |
| 3091 | | } |
| 3092 | | } |
| 3093 | | }; |
| 3094 | | |
| 3095 | | fn fmtDebug(itab: ImportTable, ctx: Context) fmt.Alt(Format, Format.default) { |
| 3096 | | return .{ .data = .{ .itab = itab, .ctx = ctx } }; |
| 3097 | | } |
| 3098 | | |
| 3099 | | const ImportIndex = u32; |
| 3100 | | }; |
| 3101 | | |
| 3102 | | fn pwriteAll(coff: *Coff, bytes: []const u8, offset: u64) error{LinkFailure}!void { |
| 3103 | | const comp = coff.base.comp; |
| 3104 | | const diags = &comp.link_diags; |
| 3105 | | coff.base.file.?.pwriteAll(bytes, offset) catch |err| { |
| 3106 | | return diags.fail("failed to write: {s}", .{@errorName(err)}); |
| 3107 | | }; |
| 3108 | | } |
| 3109 | | |
| 3110 | | /// This is the start of a Portable Executable (PE) file. |
| 3111 | | /// It starts with a MS-DOS header followed by a MS-DOS stub program. |
| 3112 | | /// This data does not change so we include it as follows in all binaries. |
| 3113 | | /// |
| 3114 | | /// In this context, |
| 3115 | | /// A "paragraph" is 16 bytes. |
| 3116 | | /// A "page" is 512 bytes. |
| 3117 | | /// A "long" is 4 bytes. |
| 3118 | | /// A "word" is 2 bytes. |
| 3119 | | pub const msdos_stub: [120]u8 = .{ |
| 3120 | | 'M', 'Z', // Magic number. Stands for Mark Zbikowski (designer of the MS-DOS executable format). |
| 3121 | | 0x78, 0x00, // Number of bytes in the last page. This matches the size of this entire MS-DOS stub. |
| 3122 | | 0x01, 0x00, // Number of pages. |
| 3123 | | 0x00, 0x00, // Number of entries in the relocation table. |
| 3124 | | 0x04, 0x00, // The number of paragraphs taken up by the header. 4 * 16 = 64, which matches the header size (all bytes before the MS-DOS stub program). |
| 3125 | | 0x00, 0x00, // The number of paragraphs required by the program. |
| 3126 | | 0x00, 0x00, // The number of paragraphs requested by the program. |
| 3127 | | 0x00, 0x00, // Initial value for SS (relocatable segment address). |
| 3128 | | 0x00, 0x00, // Initial value for SP. |
| 3129 | | 0x00, 0x00, // Checksum. |
| 3130 | | 0x00, 0x00, // Initial value for IP. |
| 3131 | | 0x00, 0x00, // Initial value for CS (relocatable segment address). |
| 3132 | | 0x40, 0x00, // Absolute offset to relocation table. 64 matches the header size (all bytes before the MS-DOS stub program). |
| 3133 | | 0x00, 0x00, // Overlay number. Zero means this is the main executable. |
| 3134 | | } |
| 3135 | | // Reserved words. |
| 3136 | | ++ .{ 0x00, 0x00 } ** 4 |
| 3137 | | // OEM-related fields. |
| 3138 | | ++ .{ |
| 3139 | | 0x00, 0x00, // OEM identifier. |
| 3140 | | 0x00, 0x00, // OEM information. |
| 3141 | | } |
| 3142 | | // Reserved words. |
| 3143 | | ++ .{ 0x00, 0x00 } ** 10 |
| 3144 | | // Address of the PE header (a long). This matches the size of this entire MS-DOS stub, so that's the address of what's after this MS-DOS stub. |
| 3145 | | ++ .{ 0x78, 0x00, 0x00, 0x00 } |
| 3146 | | // What follows is a 16-bit x86 MS-DOS program of 7 instructions that prints the bytes after these instructions and then exits. |
| 3147 | | ++ .{ |
| 3148 | | // Set the value of the data segment to the same value as the code segment. |
| 3149 | | 0x0e, // push cs |
| 3150 | | 0x1f, // pop ds |
| 3151 | | // Set the DX register to the address of the message. |
| 3152 | | // If you count all bytes of these 7 instructions you get 14, so that's the address of what's after these instructions. |
| 3153 | | 0xba, 14, 0x00, // mov dx, 14 |
| 3154 | | // Set AH to the system call code for printing a message. |
| 3155 | | 0xb4, 0x09, // mov ah, 0x09 |
| 3156 | | // Perform the system call to print the message. |
| 3157 | | 0xcd, 0x21, // int 0x21 |
| 3158 | | // Set AH to 0x4c which is the system call code for exiting, and set AL to 0x01 which is the exit code. |
| 3159 | | 0xb8, 0x01, 0x4c, // mov ax, 0x4c01 |
| 3160 | | // Peform the system call to exit the program with exit code 1. |
| 3161 | | 0xcd, 0x21, // int 0x21 |
| 3162 | | } |
| 3163 | | // Message to print. |
| 3164 | | ++ "This program cannot be run in DOS mode.".* |
| 3165 | | // Message terminators. |
| 3166 | | ++ .{ |
| 3167 | | '$', // We do not pass a length to the print system call; the string is terminated by this character. |
| 3168 | | 0x00, 0x00, // Terminating zero bytes. |
| 3169 | | }; |
Jacob Young <jacobly@ziglang.org> 2025-10-01 15:21:49-04:00