diff options
Diffstat (limited to 'src/link/MachO')
| -rw-r--r-- | src/link/MachO/Atom.zig | 102 | ||||
| -rw-r--r-- | src/link/MachO/Object.zig | 409 |
2 files changed, 218 insertions, 293 deletions
diff --git a/src/link/MachO/Atom.zig b/src/link/MachO/Atom.zig index 298855934e..6dbe853451 100644 --- a/src/link/MachO/Atom.zig +++ b/src/link/MachO/Atom.zig @@ -645,7 +645,6 @@ const RelocContext = struct { allocator: *Allocator, object: *Object, macho_file: *MachO, - parsed_atoms: *Object.ParsedAtoms, }; fn initRelocFromObject(rel: macho.relocation_info, context: RelocContext) !Relocation { @@ -877,12 +876,16 @@ pub fn parseRelocs(self: *Atom, relocs: []macho.relocation_info, context: RelocC .sect = context.macho_file.got_section_index.?, }; - if (context.parsed_atoms.getPtr(match)) |last| { + if (!context.object.start_atoms.contains(match)) { + try context.object.start_atoms.putNoClobber(context.allocator, match, atom); + } + + if (context.object.end_atoms.getPtr(match)) |last| { last.*.next = atom; atom.prev = last.*; last.* = atom; } else { - try context.parsed_atoms.putNoClobber(match, atom); + try context.object.end_atoms.putNoClobber(context.allocator, match, atom); } } else if (parsed_rel.payload == .unsigned) { switch (parsed_rel.where) { @@ -939,52 +942,63 @@ pub fn parseRelocs(self: *Atom, relocs: []macho.relocation_info, context: RelocC if (parsed_rel.where != .undef) break :blk; if (context.macho_file.stubs_map.contains(parsed_rel.where_index)) break :blk; - const stub_helper_atom = try context.macho_file.createStubHelperAtom(); - const laptr_atom = try context.macho_file.createLazyPointerAtom( - stub_helper_atom.local_sym_index, - parsed_rel.where_index, - ); - const stub_atom = try context.macho_file.createStubAtom(laptr_atom.local_sym_index); - try context.macho_file.stubs_map.putNoClobber(context.allocator, parsed_rel.where_index, stub_atom); // TODO clean this up! - if (context.parsed_atoms.getPtr(.{ - .seg = context.macho_file.text_segment_cmd_index.?, - .sect = context.macho_file.stub_helper_section_index.?, - })) |last| { - last.*.next = stub_helper_atom; - stub_helper_atom.prev = last.*; - last.* = stub_helper_atom; - } else { - try context.parsed_atoms.putNoClobber(.{ + const stub_helper_atom = atom: { + const atom = try context.macho_file.createStubHelperAtom(); + const match = MachO.MatchingSection{ .seg = context.macho_file.text_segment_cmd_index.?, .sect = context.macho_file.stub_helper_section_index.?, - }, stub_helper_atom); - } - if (context.parsed_atoms.getPtr(.{ - .seg = context.macho_file.text_segment_cmd_index.?, - .sect = context.macho_file.stubs_section_index.?, - })) |last| { - last.*.next = stub_atom; - stub_atom.prev = last.*; - last.* = stub_atom; - } else { - try context.parsed_atoms.putNoClobber(.{ - .seg = context.macho_file.text_segment_cmd_index.?, - .sect = context.macho_file.stubs_section_index.?, - }, stub_atom); - } - if (context.parsed_atoms.getPtr(.{ - .seg = context.macho_file.data_segment_cmd_index.?, - .sect = context.macho_file.la_symbol_ptr_section_index.?, - })) |last| { - last.*.next = laptr_atom; - laptr_atom.prev = last.*; - last.* = laptr_atom; - } else { - try context.parsed_atoms.putNoClobber(.{ + }; + if (!context.object.start_atoms.contains(match)) { + try context.object.start_atoms.putNoClobber(context.allocator, match, atom); + } + if (context.object.end_atoms.getPtr(match)) |last| { + last.*.next = atom; + atom.prev = last.*; + last.* = atom; + } else { + try context.object.end_atoms.putNoClobber(context.allocator, match, atom); + } + break :atom atom; + }; + const laptr_atom = atom: { + const atom = try context.macho_file.createLazyPointerAtom( + stub_helper_atom.local_sym_index, + parsed_rel.where_index, + ); + const match = MachO.MatchingSection{ .seg = context.macho_file.data_segment_cmd_index.?, .sect = context.macho_file.la_symbol_ptr_section_index.?, - }, laptr_atom); + }; + if (!context.object.start_atoms.contains(match)) { + try context.object.start_atoms.putNoClobber(context.allocator, match, atom); + } + if (context.object.end_atoms.getPtr(match)) |last| { + last.*.next = atom; + atom.prev = last.*; + last.* = atom; + } else { + try context.object.end_atoms.putNoClobber(context.allocator, match, atom); + } + break :atom atom; + }; + { + const atom = try context.macho_file.createStubAtom(laptr_atom.local_sym_index); + const match = MachO.MatchingSection{ + .seg = context.macho_file.text_segment_cmd_index.?, + .sect = context.macho_file.stubs_section_index.?, + }; + if (!context.object.start_atoms.contains(match)) { + try context.object.start_atoms.putNoClobber(context.allocator, match, atom); + } + if (context.object.end_atoms.getPtr(match)) |last| { + last.*.next = atom; + atom.prev = last.*; + last.* = atom; + } else { + try context.object.end_atoms.putNoClobber(context.allocator, match, atom); + } + try context.macho_file.stubs_map.putNoClobber(context.allocator, parsed_rel.where_index, atom); } } } diff --git a/src/link/MachO/Object.zig b/src/link/MachO/Object.zig index 27da019be8..12c480b0f1 100644 --- a/src/link/MachO/Object.zig +++ b/src/link/MachO/Object.zig @@ -31,14 +31,12 @@ header: ?macho.mach_header_64 = null, load_commands: std.ArrayListUnmanaged(LoadCommand) = .{}, segment_cmd_index: ?u16 = null, +text_section_index: ?u16 = null, symtab_cmd_index: ?u16 = null, dysymtab_cmd_index: ?u16 = null, build_version_cmd_index: ?u16 = null, data_in_code_cmd_index: ?u16 = null, -text_section_index: ?u16 = null, -mod_init_func_section_index: ?u16 = null, - // __DWARF segment sections dwarf_debug_info_index: ?u16 = null, dwarf_debug_abbrev_index: ?u16 = null, @@ -56,7 +54,9 @@ tu_name: ?[]const u8 = null, tu_comp_dir: ?[]const u8 = null, mtime: ?u64 = null, -atoms: std.ArrayListUnmanaged(*Atom) = .{}, +contained_atoms: std.ArrayListUnmanaged(*Atom) = .{}, +start_atoms: std.AutoHashMapUnmanaged(MachO.MatchingSection, *Atom) = .{}, +end_atoms: std.AutoHashMapUnmanaged(MachO.MatchingSection, *Atom) = .{}, sections_as_symbols: std.AutoHashMapUnmanaged(u16, u32) = .{}, // TODO symbol mapping and its inverse can probably be simple arrays @@ -138,12 +138,15 @@ pub fn deinit(self: *Object, allocator: *Allocator) void { self.data_in_code_entries.deinit(allocator); self.symtab.deinit(allocator); self.strtab.deinit(allocator); - self.atoms.deinit(allocator); self.sections_as_symbols.deinit(allocator); self.symbol_mapping.deinit(allocator); self.reverse_symbol_mapping.deinit(allocator); allocator.free(self.name); + self.contained_atoms.deinit(allocator); + self.start_atoms.deinit(allocator); + self.end_atoms.deinit(allocator); + if (self.debug_info) |*db| { db.deinit(allocator); } @@ -157,6 +160,67 @@ pub fn deinit(self: *Object, allocator: *Allocator) void { } } +pub fn free(self: *Object, allocator: *Allocator, macho_file: *MachO) void { + log.debug("freeObject {*}", .{self}); + + var it = self.end_atoms.iterator(); + while (it.next()) |entry| { + const match = entry.key_ptr.*; + const first_atom = self.start_atoms.get(match).?; + const last_atom = entry.value_ptr.*; + var atom = first_atom; + + while (true) { + if (atom.local_sym_index != 0) { + macho_file.locals_free_list.append(allocator, atom.local_sym_index) catch {}; + const local = &macho_file.locals.items[atom.local_sym_index]; + local.n_type = 0; + atom.local_sym_index = 0; + } + if (atom == last_atom) { + break; + } + if (atom.next) |next| { + atom = next; + } else break; + } + } + + self.freeAtoms(macho_file); +} + +fn freeAtoms(self: *Object, macho_file: *MachO) void { + var it = self.end_atoms.iterator(); + while (it.next()) |entry| { + const match = entry.key_ptr.*; + var first_atom: *Atom = self.start_atoms.get(match).?; + var last_atom: *Atom = entry.value_ptr.*; + + if (macho_file.atoms.getPtr(match)) |atom_ptr| { + if (atom_ptr.* == last_atom) { + if (first_atom.prev) |prev| { + // TODO shrink the section size here + atom_ptr.* = prev; + } else { + _ = macho_file.atoms.fetchRemove(match); + } + } + } + + if (first_atom.prev) |prev| { + prev.next = last_atom.next; + } else { + first_atom.prev = null; + } + + if (last_atom.next) |next| { + next.prev = last_atom.prev; + } else { + last_atom.next = null; + } + } +} + pub fn parse(self: *Object, allocator: *Allocator, target: std.Target) !void { const reader = self.file.reader(); if (self.file_offset) |offset| { @@ -226,10 +290,6 @@ pub fn readLoadCommands(self: *Object, allocator: *Allocator, reader: anytype) ! if (mem.eql(u8, sectname, "__text")) { self.text_section_index = index; } - } else if (mem.eql(u8, segname, "__DATA")) { - if (mem.eql(u8, sectname, "__mod_init_func")) { - self.mod_init_func_section_index = index; - } } sect.offset += offset; @@ -320,7 +380,6 @@ const Context = struct { object: *Object, macho_file: *MachO, match: MachO.MatchingSection, - parsed_atoms: *ParsedAtoms, }; const AtomParser = struct { @@ -437,7 +496,6 @@ const AtomParser = struct { .allocator = context.allocator, .object = context.object, .macho_file = context.macho_file, - .parsed_atoms = context.parsed_atoms, }); if (context.macho_file.has_dices) { @@ -463,18 +521,10 @@ const AtomParser = struct { } }; -pub const ParsedAtoms = std.AutoHashMap(MachO.MatchingSection, *Atom); - -pub fn parseIntoAtoms( - self: *Object, - allocator: *Allocator, - object_id: u16, - macho_file: *MachO, -) !ParsedAtoms { +pub fn parseIntoAtoms(self: *Object, allocator: *Allocator, macho_file: *MachO) !void { const tracy = trace(@src()); defer tracy.end(); - var parsed_atoms = ParsedAtoms.init(allocator); const seg = self.load_commands.items[self.segment_cmd_index.?].Segment; log.debug("analysing {s}", .{self.name}); @@ -540,16 +590,6 @@ pub fn parseIntoAtoms( // Symbols within this section only. const filtered_nlists = NlistWithIndex.filterInSection(sorted_nlists, sect); - // TODO rewrite and re-enable dead-code stripping optimisation. I think it might make sense - // to do this in a standalone pass after we parse the sections as atoms. - // In release mode, if the object file was generated with dead code stripping optimisations, - // note it now and parse sections as atoms. - // const is_splittable = blk: { - // if (macho_file.base.options.optimize_mode == .Debug) break :blk false; - // break :blk self.header.?.flags & macho.MH_SUBSECTIONS_VIA_SYMBOLS != 0; - // }; - const is_splittable = false; - macho_file.has_dices = macho_file.has_dices or blk: { if (self.text_section_index) |index| { if (index != id) break :blk false; @@ -560,237 +600,108 @@ pub fn parseIntoAtoms( }; macho_file.has_stabs = macho_file.has_stabs or self.debug_info != null; - next: { - if (is_splittable) atoms: { - if (filtered_nlists.len == 0) break :atoms; - - // If the first nlist does not match the start of the section, - // then we need to encapsulate the memory range [section start, first symbol) - // as a temporary symbol and insert the matching Atom. - const first_nlist = filtered_nlists[0].nlist; - if (first_nlist.n_value > sect.addr) { - const sym_name = try std.fmt.allocPrint(allocator, "l_{s}_{s}_{s}", .{ - self.name, - segmentName(sect), - sectionName(sect), - }); - defer allocator.free(sym_name); - - const atom_local_sym_index = self.sections_as_symbols.get(sect_id) orelse blk: { - const atom_local_sym_index = @intCast(u32, macho_file.locals.items.len); - try macho_file.locals.append(allocator, .{ - .n_strx = try macho_file.makeString(sym_name), - .n_type = macho.N_SECT, - .n_sect = @intCast(u8, macho_file.section_ordinals.getIndex(match).? + 1), - .n_desc = 0, - .n_value = 0, - }); - try self.sections_as_symbols.putNoClobber(allocator, sect_id, atom_local_sym_index); - break :blk atom_local_sym_index; - }; - const atom_code = code[0 .. first_nlist.n_value - sect.addr]; - const atom_size = atom_code.len; - const atom = try macho_file.createEmptyAtom(atom_local_sym_index, atom_size, sect.@"align"); - - const is_zerofill = blk: { - const section_type = commands.sectionType(sect); - break :blk section_type == macho.S_ZEROFILL or section_type == macho.S_THREAD_LOCAL_ZEROFILL; - }; - if (!is_zerofill) { - mem.copy(u8, atom.code.items, atom_code); - } - - try atom.parseRelocs(relocs, .{ - .base_addr = sect.addr, - .base_offset = 0, - .allocator = allocator, - .object = self, - .macho_file = macho_file, - .parsed_atoms = &parsed_atoms, - }); - - if (macho_file.has_dices) { - const dices = filterDice(self.data_in_code_entries.items, sect.addr, sect.addr + atom_size); - try atom.dices.ensureTotalCapacity(allocator, dices.len); - - for (dices) |dice| { - atom.dices.appendAssumeCapacity(.{ - .offset = dice.offset - try math.cast(u32, sect.addr), - .length = dice.length, - .kind = dice.kind, - }); - } - } - - if (parsed_atoms.getPtr(match)) |last| { - last.*.next = atom; - atom.prev = last.*; - last.* = atom; - } else { - try parsed_atoms.putNoClobber(match, atom); - } - try self.atoms.append(allocator, atom); - } - - var parser = AtomParser{ - .section = sect, - .code = code, - .relocs = relocs, - .nlists = filtered_nlists, - }; - - while (try parser.next(.{ - .allocator = allocator, - .object = self, - .macho_file = macho_file, - .match = match, - .parsed_atoms = &parsed_atoms, - })) |atom| { - const sym = macho_file.locals.items[atom.local_sym_index]; - const is_ext = blk: { - const orig_sym_id = self.reverse_symbol_mapping.get(atom.local_sym_index) orelse unreachable; - break :blk MachO.symbolIsExt(self.symtab.items[orig_sym_id]); - }; - if (is_ext) { - if (macho_file.symbol_resolver.get(sym.n_strx)) |resolv| { - assert(resolv.where == .global); - if (resolv.file != object_id) { - log.debug("deduping definition of {s} in {s}", .{ - macho_file.getString(sym.n_strx), - self.name, - }); - log.debug(" already defined in {s}", .{ - macho_file.objects.items[resolv.file].name, - }); - continue; - } - } - } + // Since there is no symbol to refer to this atom, we create + // a temp one, unless we already did that when working out the relocations + // of other atoms. + const sym_name = try std.fmt.allocPrint(allocator, "l_{s}_{s}_{s}", .{ + self.name, + segmentName(sect), + sectionName(sect), + }); + defer allocator.free(sym_name); + + const atom_local_sym_index = self.sections_as_symbols.get(sect_id) orelse blk: { + const atom_local_sym_index = @intCast(u32, macho_file.locals.items.len); + try macho_file.locals.append(allocator, .{ + .n_strx = try macho_file.makeString(sym_name), + .n_type = macho.N_SECT, + .n_sect = @intCast(u8, macho_file.section_ordinals.getIndex(match).? + 1), + .n_desc = 0, + .n_value = 0, + }); + try self.sections_as_symbols.putNoClobber(allocator, sect_id, atom_local_sym_index); + break :blk atom_local_sym_index; + }; + const atom = try macho_file.createEmptyAtom(atom_local_sym_index, sect.size, sect.@"align"); - if (sym.n_value == sect.addr) { - if (self.sections_as_symbols.get(sect_id)) |alias| { - // In x86_64 relocs, it can so happen that the compiler refers to the same - // atom by both the actual assigned symbol and the start of the section. In this - // case, we need to link the two together so add an alias. - try atom.aliases.append(allocator, alias); - } - } + const is_zerofill = blk: { + const section_type = commands.sectionType(sect); + break :blk section_type == macho.S_ZEROFILL or section_type == macho.S_THREAD_LOCAL_ZEROFILL; + }; + if (!is_zerofill) { + mem.copy(u8, atom.code.items, code); + } - if (parsed_atoms.getPtr(match)) |last| { - last.*.next = atom; - atom.prev = last.*; - last.* = atom; - } else { - try parsed_atoms.putNoClobber(match, atom); - } - try self.atoms.append(allocator, atom); - } + try atom.parseRelocs(relocs, .{ + .base_addr = sect.addr, + .base_offset = 0, + .allocator = allocator, + .object = self, + .macho_file = macho_file, + }); - break :next; - } + if (macho_file.has_dices) { + const dices = filterDice(self.data_in_code_entries.items, sect.addr, sect.addr + sect.size); + try atom.dices.ensureTotalCapacity(allocator, dices.len); - // Since there is no symbol to refer to this atom, we create - // a temp one, unless we already did that when working out the relocations - // of other atoms. - const sym_name = try std.fmt.allocPrint(allocator, "l_{s}_{s}_{s}", .{ - self.name, - segmentName(sect), - sectionName(sect), - }); - defer allocator.free(sym_name); - - const atom_local_sym_index = self.sections_as_symbols.get(sect_id) orelse blk: { - const atom_local_sym_index = @intCast(u32, macho_file.locals.items.len); - try macho_file.locals.append(allocator, .{ - .n_strx = try macho_file.makeString(sym_name), - .n_type = macho.N_SECT, - .n_sect = @intCast(u8, macho_file.section_ordinals.getIndex(match).? + 1), - .n_desc = 0, - .n_value = 0, + for (dices) |dice| { + atom.dices.appendAssumeCapacity(.{ + .offset = dice.offset - try math.cast(u32, sect.addr), + .length = dice.length, + .kind = dice.kind, }); - try self.sections_as_symbols.putNoClobber(allocator, sect_id, atom_local_sym_index); - break :blk atom_local_sym_index; - }; - const atom = try macho_file.createEmptyAtom(atom_local_sym_index, sect.size, sect.@"align"); - - const is_zerofill = blk: { - const section_type = commands.sectionType(sect); - break :blk section_type == macho.S_ZEROFILL or section_type == macho.S_THREAD_LOCAL_ZEROFILL; - }; - if (!is_zerofill) { - mem.copy(u8, atom.code.items, code); - } - - try atom.parseRelocs(relocs, .{ - .base_addr = sect.addr, - .base_offset = 0, - .allocator = allocator, - .object = self, - .macho_file = macho_file, - .parsed_atoms = &parsed_atoms, - }); - - if (macho_file.has_dices) { - const dices = filterDice(self.data_in_code_entries.items, sect.addr, sect.addr + sect.size); - try atom.dices.ensureTotalCapacity(allocator, dices.len); - - for (dices) |dice| { - atom.dices.appendAssumeCapacity(.{ - .offset = dice.offset - try math.cast(u32, sect.addr), - .length = dice.length, - .kind = dice.kind, - }); - } } + } - // Since this is atom gets a helper local temporary symbol that didn't exist - // in the object file which encompasses the entire section, we need traverse - // the filtered symbols and note which symbol is contained within so that - // we can properly allocate addresses down the line. - // While we're at it, we need to update segment,section mapping of each symbol too. - try atom.contained.ensureTotalCapacity(allocator, filtered_nlists.len); - - for (filtered_nlists) |nlist_with_index| { - const nlist = nlist_with_index.nlist; - const local_sym_index = self.symbol_mapping.get(nlist_with_index.index) orelse unreachable; - const local = &macho_file.locals.items[local_sym_index]; - local.n_sect = @intCast(u8, macho_file.section_ordinals.getIndex(match).? + 1); - - const stab: ?Atom.Stab = if (self.debug_info) |di| blk: { - // TODO there has to be a better to handle this. - for (di.inner.func_list.items) |func| { - if (func.pc_range) |range| { - if (nlist.n_value >= range.start and nlist.n_value < range.end) { - break :blk Atom.Stab{ - .function = range.end - range.start, - }; - } + // Since this is atom gets a helper local temporary symbol that didn't exist + // in the object file which encompasses the entire section, we need traverse + // the filtered symbols and note which symbol is contained within so that + // we can properly allocate addresses down the line. + // While we're at it, we need to update segment,section mapping of each symbol too. + try atom.contained.ensureTotalCapacity(allocator, filtered_nlists.len); + + for (filtered_nlists) |nlist_with_index| { + const nlist = nlist_with_index.nlist; + const local_sym_index = self.symbol_mapping.get(nlist_with_index.index) orelse unreachable; + const local = &macho_file.locals.items[local_sym_index]; + local.n_sect = @intCast(u8, macho_file.section_ordinals.getIndex(match).? + 1); + + const stab: ?Atom.Stab = if (self.debug_info) |di| blk: { + // TODO there has to be a better to handle this. + for (di.inner.func_list.items) |func| { + if (func.pc_range) |range| { + if (nlist.n_value >= range.start and nlist.n_value < range.end) { + break :blk Atom.Stab{ + .function = range.end - range.start, + }; } } - // TODO - // if (zld.globals.contains(zld.getString(sym.strx))) break :blk .global; - break :blk .static; - } else null; - - atom.contained.appendAssumeCapacity(.{ - .local_sym_index = local_sym_index, - .offset = nlist.n_value - sect.addr, - .stab = stab, - }); - } + } + // TODO + // if (zld.globals.contains(zld.getString(sym.strx))) break :blk .global; + break :blk .static; + } else null; + + atom.contained.appendAssumeCapacity(.{ + .local_sym_index = local_sym_index, + .offset = nlist.n_value - sect.addr, + .stab = stab, + }); + } - if (parsed_atoms.getPtr(match)) |last| { - last.*.next = atom; - atom.prev = last.*; - last.* = atom; - } else { - try parsed_atoms.putNoClobber(match, atom); - } - try self.atoms.append(allocator, atom); + if (!self.start_atoms.contains(match)) { + try self.start_atoms.putNoClobber(allocator, match, atom); } - } - return parsed_atoms; + if (self.end_atoms.getPtr(match)) |last| { + last.*.next = atom; + atom.prev = last.*; + last.* = atom; + } else { + try self.end_atoms.putNoClobber(allocator, match, atom); + } + try self.contained_atoms.append(allocator, atom); + } } fn parseSymtab(self: *Object, allocator: *Allocator) !void { |