Commit 44a052a65f
Changed files (2)
src
src/link/MachO.zig
@@ -167,9 +167,11 @@ last_text_block: ?*TextBlock = null,
pie_fixups: std.ArrayListUnmanaged(PieFixup) = .{},
stub_fixups: std.ArrayListUnmanaged(StubFixup) = .{},
+externs: std.StringHashMapUnmanaged(u32) = .{},
pub const StubFixup = struct {
- symbol: usize,
+ symbol: u32,
+ exists: bool,
start: usize,
len: usize,
};
@@ -1263,56 +1265,57 @@ pub fn updateDecl(self: *MachO, module: *Module, decl: *Module.Decl) !void {
const stub_h = &text_segment.sections.items[self.stub_helper_section_index.?];
const data_segment = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const la_ptr = &data_segment.sections.items[self.la_symbol_ptr_section_index.?];
- for (self.stub_fixups.items) |fixup, idx| {
- const i = @intCast(u32, idx);
+ for (self.stub_fixups.items) |fixup| {
// TODO increment offset for stub writing
- const stub_addr = stubs.addr + i * stubs.reserved2;
+ const stub_addr = stubs.addr + fixup.symbol * stubs.reserved2;
const text_addr = symbol.n_value + fixup.start;
const displacement = @intCast(u32, stub_addr - text_addr);
var placeholder = code_buffer.items[fixup.start..][0..fixup.len];
mem.writeIntSliceLittle(u32, placeholder, aarch64.Instruction.bl(@intCast(i28, displacement)).toU32());
- const end = stub_h.addr + self.next_stub_helper_off.? - stub_h.offset;
- var buf: [@sizeOf(u64)]u8 = undefined;
- mem.writeIntLittle(u64, &buf, end);
- try self.base.file.?.pwriteAll(&buf, la_ptr.offset + i * @sizeOf(u64));
-
- const la_ptr_addr = la_ptr.addr + i * @sizeOf(u64);
- const displacement2 = la_ptr_addr - stub_addr;
- var ccode: [2 * @sizeOf(u32)]u8 = undefined;
- mem.writeIntLittle(u32, ccode[0..4], aarch64.Instruction.ldr(.x16, .{
- .literal = @intCast(u19, displacement2 / 4),
- }).toU32());
- mem.writeIntLittle(u32, ccode[4..8], aarch64.Instruction.br(.x16).toU32());
- try self.base.file.?.pwriteAll(&ccode, stubs.offset + i * stubs.reserved2);
-
- const displacement3 = @intCast(i64, stub_h.addr) - @intCast(i64, end + 4);
- var cccode: [3 * @sizeOf(u32)]u8 = undefined;
- mem.writeIntLittle(u32, cccode[0..4], aarch64.Instruction.ldr(.w16, .{
- .literal = 0x2,
- }).toU32());
- mem.writeIntLittle(u32, cccode[4..8], aarch64.Instruction.b(@intCast(i28, displacement3)).toU32());
- mem.writeIntLittle(u32, cccode[8..12], i * 0xd);
- try self.base.file.?.pwriteAll(&cccode, self.next_stub_helper_off.?);
- self.next_stub_helper_off = self.next_stub_helper_off.? + 3 * @sizeOf(u32);
-
- try self.rebase_info_table.symbols.append(self.base.allocator, .{
- .segment = 3,
- .offset = i * stubs.reserved2,
- });
- self.rebase_info_dirty = true;
-
- const sym = self.undef_symbols.items[fixup.symbol];
- const name_str = self.getString(sym.n_strx);
- var name = try self.base.allocator.alloc(u8, name_str.len);
- mem.copy(u8, name, name_str);
- try self.lazy_binding_info_table.symbols.append(self.base.allocator, .{
- .segment = 3,
- .offset = i * @sizeOf(u64),
- .dylib_ordinal = 1,
- .name = name,
- });
- self.lazy_binding_info_dirty = true;
+ if (!fixup.exists) {
+ const end = stub_h.addr + self.next_stub_helper_off.? - stub_h.offset;
+ var buf: [@sizeOf(u64)]u8 = undefined;
+ mem.writeIntLittle(u64, &buf, end);
+ try self.base.file.?.pwriteAll(&buf, la_ptr.offset + fixup.symbol * @sizeOf(u64));
+
+ const la_ptr_addr = la_ptr.addr + fixup.symbol * @sizeOf(u64);
+ const displacement2 = la_ptr_addr - stub_addr;
+ var ccode: [2 * @sizeOf(u32)]u8 = undefined;
+ mem.writeIntLittle(u32, ccode[0..4], aarch64.Instruction.ldr(.x16, .{
+ .literal = @intCast(u19, displacement2 / 4),
+ }).toU32());
+ mem.writeIntLittle(u32, ccode[4..8], aarch64.Instruction.br(.x16).toU32());
+ try self.base.file.?.pwriteAll(&ccode, stubs.offset + fixup.symbol * stubs.reserved2);
+
+ const displacement3 = @intCast(i64, stub_h.addr) - @intCast(i64, end + 4);
+ var cccode: [3 * @sizeOf(u32)]u8 = undefined;
+ mem.writeIntLittle(u32, cccode[0..4], aarch64.Instruction.ldr(.w16, .{
+ .literal = 0x2,
+ }).toU32());
+ mem.writeIntLittle(u32, cccode[4..8], aarch64.Instruction.b(@intCast(i28, displacement3)).toU32());
+ mem.writeIntLittle(u32, cccode[8..12], fixup.symbol * 0xd);
+ try self.base.file.?.pwriteAll(&cccode, self.next_stub_helper_off.?);
+ self.next_stub_helper_off = self.next_stub_helper_off.? + 3 * @sizeOf(u32);
+
+ try self.rebase_info_table.symbols.append(self.base.allocator, .{
+ .segment = 3,
+ .offset = fixup.symbol * stubs.reserved2,
+ });
+ self.rebase_info_dirty = true;
+
+ const sym = self.undef_symbols.items[fixup.symbol + 1];
+ const name_str = self.getString(sym.n_strx);
+ var name = try self.base.allocator.alloc(u8, name_str.len);
+ mem.copy(u8, name, name_str);
+ try self.lazy_binding_info_table.symbols.append(self.base.allocator, .{
+ .segment = 3,
+ .offset = fixup.symbol * @sizeOf(u64),
+ .dylib_ordinal = 1,
+ .name = name,
+ });
+ self.lazy_binding_info_dirty = true;
+ }
}
self.stub_fixups.shrinkRetainingCapacity(0);
src/codegen.zig
@@ -1862,18 +1862,28 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
} else if (func_value.castTag(.extern_fn)) |func_payload| {
const decl = func_payload.data;
const decl_name = try std.fmt.allocPrint(self.bin_file.allocator, "_{s}", .{decl.name});
- defer self.bin_file.allocator.free(decl_name);
- const name = try macho_file.makeString(decl_name);
- const symbol = macho_file.undef_symbols.items.len;
- try macho_file.undef_symbols.append(self.bin_file.allocator, .{
- .n_strx = name,
- .n_type = std.macho.N_UNDF | std.macho.N_EXT,
- .n_sect = 0,
- .n_desc = std.macho.REFERENCE_FLAG_UNDEFINED_NON_LAZY | std.macho.N_SYMBOL_RESOLVER,
- .n_value = 0,
- });
+ const exists: bool = macho_file.externs.contains(decl_name);
+ const symbol: u32 = blk: {
+ if (macho_file.externs.get(decl_name)) |index| {
+ self.bin_file.allocator.free(decl_name);
+ break :blk index;
+ } else {
+ const extern_index = @intCast(u32, macho_file.undef_symbols.items.len - 1); // TODO
+ try macho_file.externs.putNoClobber(self.bin_file.allocator, decl_name, extern_index);
+ const name = try macho_file.makeString(decl_name);
+ try macho_file.undef_symbols.append(self.bin_file.allocator, .{
+ .n_strx = name,
+ .n_type = std.macho.N_UNDF | std.macho.N_EXT,
+ .n_sect = 0,
+ .n_desc = std.macho.REFERENCE_FLAG_UNDEFINED_NON_LAZY | std.macho.N_SYMBOL_RESOLVER,
+ .n_value = 0,
+ });
+ break :blk extern_index;
+ }
+ };
try macho_file.stub_fixups.append(self.bin_file.allocator, .{
.symbol = symbol,
+ .exists = exists,
.start = self.code.items.len,
.len = 4,
});