authorgravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2021-09-21 11:05:22+02:00
committergravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2021-09-21 11:05:22+02:00
logd722f0cc627c34f2c18681202a512d9aaa58fb18
treecd332e7430de06d0fba74aad5104e2ee6da99edf
parent5269cbea202c6a81108390f4c47bc8a04fc6d1ff

macho: do not write temp and noname symbols to symtab

Remove currently obsolete AtomParser from Object.

3 files changed, 14 insertions(+), 169 deletions(-)

src/link/MachO.zig+12-7
...@@ -1869,7 +1869,7 @@ fn writeAtoms(self: *MachO) !void {...@@ -1869,7 +1869,7 @@ fn writeAtoms(self: *MachO) !void {
1869pub fn createGotAtom(self: *MachO, key: GotIndirectionKey) !*Atom {1869pub fn createGotAtom(self: *MachO, key: GotIndirectionKey) !*Atom {
1870 const local_sym_index = @intCast(u32, self.locals.items.len);1870 const local_sym_index = @intCast(u32, self.locals.items.len);
1871 try self.locals.append(self.base.allocator, .{1871 try self.locals.append(self.base.allocator, .{
1872 .n_strx = try self.makeString("l_zld_got_entry"),1872 .n_strx = 0,
1873 .n_type = macho.N_SECT,1873 .n_type = macho.N_SECT,
1874 .n_sect = 0,1874 .n_sect = 0,
1875 .n_desc = 0,1875 .n_desc = 0,
...@@ -1907,7 +1907,7 @@ fn createDyldPrivateAtom(self: *MachO) !void {...@@ -1907,7 +1907,7 @@ fn createDyldPrivateAtom(self: *MachO) !void {
1907 const local_sym_index = @intCast(u32, self.locals.items.len);1907 const local_sym_index = @intCast(u32, self.locals.items.len);
1908 const sym = try self.locals.addOne(self.base.allocator);1908 const sym = try self.locals.addOne(self.base.allocator);
1909 sym.* = .{1909 sym.* = .{
1910 .n_strx = try self.makeString("l_zld_dyld_private"),1910 .n_strx = 0,
1911 .n_type = macho.N_SECT,1911 .n_type = macho.N_SECT,
1912 .n_sect = 0,1912 .n_sect = 0,
1913 .n_desc = 0,1913 .n_desc = 0,
...@@ -1941,7 +1941,7 @@ fn createStubHelperPreambleAtom(self: *MachO) !void {...@@ -1941,7 +1941,7 @@ fn createStubHelperPreambleAtom(self: *MachO) !void {
1941 const local_sym_index = @intCast(u32, self.locals.items.len);1941 const local_sym_index = @intCast(u32, self.locals.items.len);
1942 const sym = try self.locals.addOne(self.base.allocator);1942 const sym = try self.locals.addOne(self.base.allocator);
1943 sym.* = .{1943 sym.* = .{
1944 .n_strx = try self.makeString("l_zld_stub_preamble"),1944 .n_strx = 0,
1945 .n_type = macho.N_SECT,1945 .n_type = macho.N_SECT,
1946 .n_sect = 0,1946 .n_sect = 0,
1947 .n_desc = 0,1947 .n_desc = 0,
...@@ -2083,7 +2083,7 @@ pub fn createStubHelperAtom(self: *MachO) !*Atom {...@@ -2083,7 +2083,7 @@ pub fn createStubHelperAtom(self: *MachO) !*Atom {
2083 };2083 };
2084 const local_sym_index = @intCast(u32, self.locals.items.len);2084 const local_sym_index = @intCast(u32, self.locals.items.len);
2085 try self.locals.append(self.base.allocator, .{2085 try self.locals.append(self.base.allocator, .{
2086 .n_strx = try self.makeString("l_zld_stub_in_stub_helper"),2086 .n_strx = 0,
2087 .n_type = macho.N_SECT,2087 .n_type = macho.N_SECT,
2088 .n_sect = 0,2088 .n_sect = 0,
2089 .n_desc = 0,2089 .n_desc = 0,
...@@ -2138,7 +2138,7 @@ pub fn createStubHelperAtom(self: *MachO) !*Atom {...@@ -2138,7 +2138,7 @@ pub fn createStubHelperAtom(self: *MachO) !*Atom {
2138pub fn createLazyPointerAtom(self: *MachO, stub_sym_index: u32, lazy_binding_sym_index: u32) !*Atom {2138pub fn createLazyPointerAtom(self: *MachO, stub_sym_index: u32, lazy_binding_sym_index: u32) !*Atom {
2139 const local_sym_index = @intCast(u32, self.locals.items.len);2139 const local_sym_index = @intCast(u32, self.locals.items.len);
2140 try self.locals.append(self.base.allocator, .{2140 try self.locals.append(self.base.allocator, .{
2141 .n_strx = try self.makeString("l_zld_lazy_ptr"),2141 .n_strx = 0,
2142 .n_type = macho.N_SECT,2142 .n_type = macho.N_SECT,
2143 .n_sect = 0,2143 .n_sect = 0,
2144 .n_desc = 0,2144 .n_desc = 0,
...@@ -2179,7 +2179,7 @@ pub fn createStubAtom(self: *MachO, laptr_sym_index: u32) !*Atom {...@@ -2179,7 +2179,7 @@ pub fn createStubAtom(self: *MachO, laptr_sym_index: u32) !*Atom {
2179 };2179 };
2180 const local_sym_index = @intCast(u32, self.locals.items.len);2180 const local_sym_index = @intCast(u32, self.locals.items.len);
2181 try self.locals.append(self.base.allocator, .{2181 try self.locals.append(self.base.allocator, .{
2182 .n_strx = try self.makeString("l_zld_stub"),2182 .n_strx = 0,
2183 .n_type = macho.N_SECT,2183 .n_type = macho.N_SECT,
2184 .n_sect = 0,2184 .n_sect = 0,
2185 .n_desc = 0,2185 .n_desc = 0,
...@@ -4741,7 +4741,12 @@ fn writeSymbolTable(self: *MachO) !void {...@@ -4741,7 +4741,12 @@ fn writeSymbolTable(self: *MachO) !void {
47414741
4742 var locals = std.ArrayList(macho.nlist_64).init(self.base.allocator);4742 var locals = std.ArrayList(macho.nlist_64).init(self.base.allocator);
4743 defer locals.deinit();4743 defer locals.deinit();
4744 try locals.appendSlice(self.locals.items);4744
4745 for (self.locals.items) |sym| {
4746 if (sym.n_strx == 0) continue;
4747 if (symbolIsTemp(sym, self.getString(sym.n_strx))) continue;
4748 try locals.append(sym);
4749 }
47454750
4746 if (self.has_stabs) {4751 if (self.has_stabs) {
4747 for (self.objects.items) |object| {4752 for (self.objects.items) |object| {
src/link/MachO/Atom.zig+1-8
...@@ -663,15 +663,8 @@ fn initRelocFromObject(rel: macho.relocation_info, context: RelocContext) !Reloc...@@ -663,15 +663,8 @@ fn initRelocFromObject(rel: macho.relocation_info, context: RelocContext) !Reloc
663 const sect = seg.sections.items[sect_id];663 const sect = seg.sections.items[sect_id];
664 const match = (try context.macho_file.getMatchingSection(sect)) orelse unreachable;664 const match = (try context.macho_file.getMatchingSection(sect)) orelse unreachable;
665 const local_sym_index = @intCast(u32, context.macho_file.locals.items.len);665 const local_sym_index = @intCast(u32, context.macho_file.locals.items.len);
666 const sym_name = try std.fmt.allocPrint(context.allocator, "l_{s}_{s}_{s}", .{
667 context.object.name,
668 commands.segmentName(sect),
669 commands.sectionName(sect),
670 });
671 defer context.allocator.free(sym_name);
672
673 try context.macho_file.locals.append(context.allocator, .{666 try context.macho_file.locals.append(context.allocator, .{
674 .n_strx = try context.macho_file.makeString(sym_name),667 .n_strx = 0,
675 .n_type = macho.N_SECT,668 .n_type = macho.N_SECT,
676 .n_sect = @intCast(u8, context.macho_file.section_ordinals.getIndex(match).? + 1),669 .n_sect = @intCast(u8, context.macho_file.section_ordinals.getIndex(match).? + 1),
677 .n_desc = 0,670 .n_desc = 0,
src/link/MachO/Object.zig+1-154
...@@ -375,152 +375,6 @@ fn filterDice(dices: []macho.data_in_code_entry, start_addr: u64, end_addr: u64)...@@ -375,152 +375,6 @@ fn filterDice(dices: []macho.data_in_code_entry, start_addr: u64, end_addr: u64)
375 return dices[start..end];375 return dices[start..end];
376}376}
377377
378const Context = struct {
379 allocator: *Allocator,
380 object: *Object,
381 macho_file: *MachO,
382 match: MachO.MatchingSection,
383};
384
385const AtomParser = struct {
386 section: macho.section_64,
387 code: []u8,
388 relocs: []macho.relocation_info,
389 nlists: []NlistWithIndex,
390 index: u32 = 0,
391
392 fn peek(self: AtomParser) ?NlistWithIndex {
393 return if (self.index + 1 < self.nlists.len) self.nlists[self.index + 1] else null;
394 }
395
396 fn lessThanBySeniority(context: Context, lhs: NlistWithIndex, rhs: NlistWithIndex) bool {
397 if (!MachO.symbolIsExt(rhs.nlist)) {
398 return MachO.symbolIsTemp(lhs.nlist, context.object.getString(lhs.nlist.n_strx));
399 } else if (MachO.symbolIsPext(rhs.nlist) or MachO.symbolIsWeakDef(rhs.nlist)) {
400 return !MachO.symbolIsExt(lhs.nlist);
401 } else {
402 return false;
403 }
404 }
405
406 pub fn next(self: *AtomParser, context: Context) !?*Atom {
407 if (self.index == self.nlists.len) return null;
408
409 const tracy = trace(@src());
410 defer tracy.end();
411
412 var aliases = std.ArrayList(NlistWithIndex).init(context.allocator);
413 defer aliases.deinit();
414
415 const next_nlist: ?NlistWithIndex = blk: while (true) {
416 const curr_nlist = self.nlists[self.index];
417 try aliases.append(curr_nlist);
418
419 if (self.peek()) |next_nlist| {
420 if (curr_nlist.nlist.n_value == next_nlist.nlist.n_value) {
421 self.index += 1;
422 continue;
423 }
424 break :blk next_nlist;
425 }
426 break :blk null;
427 } else null;
428
429 for (aliases.items) |*nlist_with_index| {
430 nlist_with_index.index = context.object.symbol_mapping.get(nlist_with_index.index) orelse unreachable;
431 }
432
433 if (aliases.items.len > 1) {
434 // Bubble-up senior symbol as the main link to the atom.
435 sort.sort(
436 NlistWithIndex,
437 aliases.items,
438 context,
439 AtomParser.lessThanBySeniority,
440 );
441 }
442
443 const senior_nlist = aliases.pop();
444 const senior_sym = &context.macho_file.locals.items[senior_nlist.index];
445 senior_sym.n_sect = @intCast(u8, context.macho_file.section_ordinals.getIndex(context.match).? + 1);
446
447 const start_addr = senior_nlist.nlist.n_value - self.section.addr;
448 const end_addr = if (next_nlist) |n| n.nlist.n_value - self.section.addr else self.section.size;
449
450 const code = self.code[start_addr..end_addr];
451 const size = code.len;
452
453 const max_align = self.section.@"align";
454 const actual_align = if (senior_nlist.nlist.n_value > 0)
455 math.min(@ctz(u64, senior_nlist.nlist.n_value), max_align)
456 else
457 max_align;
458
459 const stab: ?Atom.Stab = if (context.object.debug_info) |di| blk: {
460 // TODO there has to be a better to handle this.
461 for (di.inner.func_list.items) |func| {
462 if (func.pc_range) |range| {
463 if (senior_nlist.nlist.n_value >= range.start and senior_nlist.nlist.n_value < range.end) {
464 break :blk Atom.Stab{
465 .function = range.end - range.start,
466 };
467 }
468 }
469 }
470 // TODO
471 // if (self.macho_file.globals.contains(self.macho_file.getString(senior_sym.strx))) break :blk .global;
472 break :blk .static;
473 } else null;
474
475 const atom = try context.macho_file.createEmptyAtom(senior_nlist.index, size, actual_align);
476 atom.stab = stab;
477
478 const is_zerofill = blk: {
479 const section_type = commands.sectionType(self.section);
480 break :blk section_type == macho.S_ZEROFILL or section_type == macho.S_THREAD_LOCAL_ZEROFILL;
481 };
482 if (!is_zerofill) {
483 mem.copy(u8, atom.code.items, code);
484 }
485
486 try atom.aliases.ensureTotalCapacity(context.allocator, aliases.items.len);
487 for (aliases.items) |alias| {
488 atom.aliases.appendAssumeCapacity(alias.index);
489 const sym = &context.macho_file.locals.items[alias.index];
490 sym.n_sect = @intCast(u8, context.macho_file.section_ordinals.getIndex(context.match).? + 1);
491 }
492
493 try atom.parseRelocs(self.relocs, .{
494 .base_addr = self.section.addr,
495 .base_offset = start_addr,
496 .allocator = context.allocator,
497 .object = context.object,
498 .macho_file = context.macho_file,
499 });
500
501 if (context.macho_file.has_dices) {
502 const dices = filterDice(
503 context.object.data_in_code_entries.items,
504 senior_nlist.nlist.n_value,
505 senior_nlist.nlist.n_value + size,
506 );
507 try atom.dices.ensureTotalCapacity(context.allocator, dices.len);
508
509 for (dices) |dice| {
510 atom.dices.appendAssumeCapacity(.{
511 .offset = dice.offset - try math.cast(u32, senior_nlist.nlist.n_value),
512 .length = dice.length,
513 .kind = dice.kind,
514 });
515 }
516 }
517
518 self.index += 1;
519
520 return atom;
521 }
522};
523
524pub fn parseIntoAtoms(self: *Object, allocator: *Allocator, macho_file: *MachO) !void {378pub fn parseIntoAtoms(self: *Object, allocator: *Allocator, macho_file: *MachO) !void {
525 const tracy = trace(@src());379 const tracy = trace(@src());
526 defer tracy.end();380 defer tracy.end();
...@@ -603,17 +457,10 @@ pub fn parseIntoAtoms(self: *Object, allocator: *Allocator, macho_file: *MachO)...@@ -603,17 +457,10 @@ pub fn parseIntoAtoms(self: *Object, allocator: *Allocator, macho_file: *MachO)
603 // Since there is no symbol to refer to this atom, we create457 // Since there is no symbol to refer to this atom, we create
604 // a temp one, unless we already did that when working out the relocations458 // a temp one, unless we already did that when working out the relocations
605 // of other atoms.459 // of other atoms.
606 const sym_name = try std.fmt.allocPrint(allocator, "l_{s}_{s}_{s}", .{
607 self.name,
608 segmentName(sect),
609 sectionName(sect),
610 });
611 defer allocator.free(sym_name);
612
613 const atom_local_sym_index = self.sections_as_symbols.get(sect_id) orelse blk: {460 const atom_local_sym_index = self.sections_as_symbols.get(sect_id) orelse blk: {
614 const atom_local_sym_index = @intCast(u32, macho_file.locals.items.len);461 const atom_local_sym_index = @intCast(u32, macho_file.locals.items.len);
615 try macho_file.locals.append(allocator, .{462 try macho_file.locals.append(allocator, .{
616 .n_strx = try macho_file.makeString(sym_name),463 .n_strx = 0,
617 .n_type = macho.N_SECT,464 .n_type = macho.N_SECT,
618 .n_sect = @intCast(u8, macho_file.section_ordinals.getIndex(match).? + 1),465 .n_sect = @intCast(u8, macho_file.section_ordinals.getIndex(match).? + 1),
619 .n_desc = 0,466 .n_desc = 0,