Commit ea499203fe
Changed files (1)
src
link
src/link/MachO.zig
@@ -764,8 +764,14 @@ pub fn flush(self: *MachO, comp: *Compilation) !void {
try self.createStubHelperPreambleAtom();
if (!use_stage1) {
- // TODO this should be made common when I figure out how to prealloc space for traditional linker path.
- try self.writeStubHelperPreamble();
+ // TODO just a temp
+ const seg = self.load_commands.items[self.text_segment_cmd_index.?].Segment;
+ const sect = seg.sections.items[self.stub_helper_section_index.?];
+ self.stub_helper_stubs_start_off = sect.offset + switch (self.base.options.target.cpu.arch) {
+ .x86_64 => @intCast(u64, 15),
+ .aarch64 => @intCast(u64, 6 * @sizeOf(u32)),
+ else => unreachable,
+ };
}
// Apply pending updates
@@ -842,7 +848,6 @@ pub fn flushModule(self: *MachO, comp: *Compilation) !void {
defer tracy.end();
try self.setEntryPoint();
- try self.writeTextBlocks();
try self.writeRebaseInfoTable();
try self.writeBindInfoTable();
try self.writeLazyBindInfoTable();
@@ -1989,7 +1994,29 @@ fn createDyldPrivateAtom(self: *MachO) !void {
.n_desc = 0,
.n_value = 0,
});
- _ = try self.createEmptyAtom(match, local_sym_index, @sizeOf(u64), 3);
+ const last = self.blocks.get(match);
+ const atom = try self.createEmptyAtom(match, local_sym_index, @sizeOf(u64), 3);
+
+ if (!(build_options.is_stage1 and self.base.options.use_stage1)) {
+ const seg = self.load_commands.items[match.seg].Segment;
+ const sect = seg.sections.items[match.sect];
+ const base_addr = if (last) |last_atom| blk: {
+ const last_atom_sym = self.locals.items[last_atom.local_sym_index];
+ break :blk last_atom_sym.n_value;
+ } else sect.addr;
+ const n_sect = @intCast(u8, self.section_ordinals.getIndex(match).? + 1);
+ const atom_alignment = try math.powi(u32, 2, atom.alignment);
+ const vaddr = mem.alignForwardGeneric(u64, base_addr, atom_alignment);
+
+ const sym = &self.locals.items[local_sym_index];
+ sym.n_value = vaddr;
+ sym.n_sect = n_sect;
+
+ const file_offset = sect.offset + vaddr - sect.addr;
+ log.debug("writing code for symbol {s} at file offset 0x{x}", .{ self.getString(sym.n_strx), file_offset });
+ try self.base.file.?.pwriteAll(atom.code.items, file_offset);
+ try self.writeLocalSymbol(local_sym_index);
+ }
self.dyld_private_sym_index = local_sym_index;
}
@@ -2019,6 +2046,7 @@ fn createStubHelperPreambleAtom(self: *MachO) !void {
.n_desc = 0,
.n_value = 0,
});
+ const last = self.blocks.get(match);
const atom = try self.createEmptyAtom(match, local_sym_index, size, alignment);
switch (arch) {
.x86_64 => {
@@ -2130,6 +2158,29 @@ fn createStubHelperPreambleAtom(self: *MachO) !void {
}
self.stub_preamble_sym_index = local_sym_index;
+ if (!(build_options.is_stage1 and self.base.options.use_stage1)) {
+ const seg = self.load_commands.items[match.seg].Segment;
+ const sect = seg.sections.items[match.sect];
+ const base_addr = if (last) |last_atom| blk: {
+ const last_atom_sym = self.locals.items[last_atom.local_sym_index];
+ break :blk last_atom_sym.n_value;
+ } else sect.addr;
+ const n_sect = @intCast(u8, self.section_ordinals.getIndex(match).? + 1);
+ const atom_alignment = try math.powi(u32, 2, atom.alignment);
+ const vaddr = mem.alignForwardGeneric(u64, base_addr, atom_alignment);
+
+ const sym = &self.locals.items[local_sym_index];
+ sym.n_value = vaddr;
+ sym.n_sect = n_sect;
+
+ try atom.resolveRelocs(self);
+
+ const file_offset = sect.offset + vaddr - sect.addr;
+ log.debug("writing code for symbol {s} at file offset 0x{x}", .{ self.getString(sym.n_strx), file_offset });
+ try self.base.file.?.pwriteAll(atom.code.items, file_offset);
+ try self.writeLocalSymbol(local_sym_index);
+ }
+
// TODO this needs to be fixed
// We already prealloc stub helper size in populateMissingMetadata(), but
// perhaps it's not needed after all?
@@ -2138,139 +2189,6 @@ fn createStubHelperPreambleAtom(self: *MachO) !void {
sect.size -= size;
}
-fn writeStubHelperPreamble(self: *MachO) !void {
- const text_segment = &self.load_commands.items[self.text_segment_cmd_index.?].Segment;
- const stub_helper = &text_segment.sections.items[self.stub_helper_section_index.?];
- const data_const_segment = &self.load_commands.items[self.data_const_segment_cmd_index.?].Segment;
- const got = &data_const_segment.sections.items[self.got_section_index.?];
- const data_segment = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
- const data = &data_segment.sections.items[self.data_section_index.?];
-
- self.stub_helper_stubs_start_off = blk: {
- switch (self.base.options.target.cpu.arch) {
- .x86_64 => {
- const code_size = 15;
- var code: [code_size]u8 = undefined;
- // lea %r11, [rip + disp]
- code[0] = 0x4c;
- code[1] = 0x8d;
- code[2] = 0x1d;
- {
- const target_addr = data.addr + data.size - @sizeOf(u64);
- const displacement = try math.cast(u32, target_addr - stub_helper.addr - 7);
- mem.writeIntLittle(u32, code[3..7], displacement);
- }
- // push %r11
- code[7] = 0x41;
- code[8] = 0x53;
- // jmp [rip + disp]
- code[9] = 0xff;
- code[10] = 0x25;
- {
- const got_index = self.got_entries_map.get(.{
- .where = .undef,
- .where_index = self.dyld_stub_binder_index.?,
- }) orelse unreachable;
- const addr = got.addr + got_index * @sizeOf(u64);
- const displacement = try math.cast(u32, addr - stub_helper.addr - code_size);
- mem.writeIntLittle(u32, code[11..], displacement);
- }
- try self.base.file.?.pwriteAll(&code, stub_helper.offset);
- break :blk stub_helper.offset + code_size;
- },
- .aarch64 => {
- var code: [6 * @sizeOf(u32)]u8 = undefined;
- data_blk_outer: {
- const this_addr = stub_helper.addr;
- const target_addr = data.addr + data.size - @sizeOf(u64);
- data_blk: {
- const displacement = math.cast(i21, target_addr - this_addr) catch break :data_blk;
- // adr x17, disp
- mem.writeIntLittle(u32, code[0..4], aarch64.Instruction.adr(.x17, displacement).toU32());
- // nop
- mem.writeIntLittle(u32, code[4..8], aarch64.Instruction.nop().toU32());
- break :data_blk_outer;
- }
- data_blk: {
- const new_this_addr = this_addr + @sizeOf(u32);
- const displacement = math.cast(i21, target_addr - new_this_addr) catch break :data_blk;
- // nop
- mem.writeIntLittle(u32, code[0..4], aarch64.Instruction.nop().toU32());
- // adr x17, disp
- mem.writeIntLittle(u32, code[4..8], aarch64.Instruction.adr(.x17, displacement).toU32());
- break :data_blk_outer;
- }
- // Jump is too big, replace adr with adrp and add.
- const this_page = @intCast(i32, this_addr >> 12);
- const target_page = @intCast(i32, target_addr >> 12);
- const pages = @intCast(i21, target_page - this_page);
- mem.writeIntLittle(u32, code[0..4], aarch64.Instruction.adrp(.x17, pages).toU32());
- const narrowed = @truncate(u12, target_addr);
- mem.writeIntLittle(u32, code[4..8], aarch64.Instruction.add(.x17, .x17, narrowed, false).toU32());
- }
- // stp x16, x17, [sp, #-16]!
- code[8] = 0xf0;
- code[9] = 0x47;
- code[10] = 0xbf;
- code[11] = 0xa9;
- binder_blk_outer: {
- const got_index = self.got_entries_map.get(.{
- .where = .undef,
- .where_index = self.dyld_stub_binder_index.?,
- }) orelse unreachable;
- const this_addr = stub_helper.addr + 3 * @sizeOf(u32);
- const target_addr = got.addr + got_index * @sizeOf(u64);
- binder_blk: {
- const displacement = math.divExact(u64, target_addr - this_addr, 4) catch break :binder_blk;
- const literal = math.cast(u18, displacement) catch break :binder_blk;
- // ldr x16, label
- mem.writeIntLittle(u32, code[12..16], aarch64.Instruction.ldr(.x16, .{
- .literal = literal,
- }).toU32());
- // nop
- mem.writeIntLittle(u32, code[16..20], aarch64.Instruction.nop().toU32());
- break :binder_blk_outer;
- }
- binder_blk: {
- const new_this_addr = this_addr + @sizeOf(u32);
- const displacement = math.divExact(u64, target_addr - new_this_addr, 4) catch break :binder_blk;
- const literal = math.cast(u18, displacement) catch break :binder_blk;
- // Pad with nop to please division.
- // nop
- mem.writeIntLittle(u32, code[12..16], aarch64.Instruction.nop().toU32());
- // ldr x16, label
- mem.writeIntLittle(u32, code[16..20], aarch64.Instruction.ldr(.x16, .{
- .literal = literal,
- }).toU32());
- break :binder_blk_outer;
- }
- // Use adrp followed by ldr(immediate).
- const this_page = @intCast(i32, this_addr >> 12);
- const target_page = @intCast(i32, target_addr >> 12);
- const pages = @intCast(i21, target_page - this_page);
- mem.writeIntLittle(u32, code[12..16], aarch64.Instruction.adrp(.x16, pages).toU32());
- const narrowed = @truncate(u12, target_addr);
- const offset = try math.divExact(u12, narrowed, 8);
- mem.writeIntLittle(u32, code[16..20], aarch64.Instruction.ldr(.x16, .{
- .register = .{
- .rn = .x16,
- .offset = aarch64.Instruction.LoadStoreOffset.imm(offset),
- },
- }).toU32());
- }
- // br x16
- code[20] = 0x00;
- code[21] = 0x02;
- code[22] = 0x1f;
- code[23] = 0xd6;
- try self.base.file.?.pwriteAll(&code, stub_helper.offset);
- break :blk stub_helper.offset + 6 * @sizeOf(u32);
- },
- else => unreachable,
- }
- };
-}
-
fn resolveSymbolsInObject(
self: *MachO,
object_id: u16,
@@ -4873,7 +4791,7 @@ fn writeAllGlobalAndUndefSymbols(self: *MachO) !void {
const undefs_off = globals_off + globals_size;
const undefs_size = nundefs * @sizeOf(macho.nlist_64);
- log.debug("writing extern symbols from 0x{x} to 0x{x}", .{ undefs_off, undefs_size + undefs_off });
+ log.debug("writing undef symbols from 0x{x} to 0x{x}", .{ undefs_off, undefs_size + undefs_off });
try self.base.file.?.pwriteAll(mem.sliceAsBytes(self.undefs.items), undefs_off);
// Update dynamic symbol table.