diff --git a/src/arch/x86_64/CodeGen.zig b/src/arch/x86_64/CodeGen.zig index 32065fa1bb..53a6bfc4d9 100644 --- a/src/arch/x86_64/CodeGen.zig +++ b/src/arch/x86_64/CodeGen.zig @@ -3950,7 +3950,7 @@ fn genVarDbgInfo( leb128.writeILEB128(dbg_info.writer(), -off) catch unreachable; dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2); }, - .memory => |addr| { + .memory, .got_load, .direct_load => { const endian = self.target.cpu.arch.endian(); const ptr_width = @intCast(u8, @divExact(self.target.cpu.arch.ptrBitWidth(), 8)); const is_ptr = switch (tag) { @@ -3963,6 +3963,11 @@ fn genVarDbgInfo( 1 + ptr_width + @boolToInt(is_ptr), DW.OP.addr, // literal address }); + const offset = @intCast(u32, dbg_info.items.len); + const addr = switch (mcv) { + .memory => |addr| addr, + else => 0, + }; switch (ptr_width) { 0...4 => { try dbg_info.writer().writeInt(u32, @intCast(u32, addr), endian); @@ -3976,6 +3981,10 @@ fn genVarDbgInfo( // We need deref the address as we point to the value via GOT entry. try dbg_info.append(DW.OP.deref); } + switch (mcv) { + .got_load, .direct_load => |index| try dw.addExprlocReloc(index, offset, is_ptr), + else => {}, + } }, else => { log.debug("TODO generate debug info for {}", .{mcv}); diff --git a/src/link/Dwarf.zig b/src/link/Dwarf.zig index bd7f429177..248521c544 100644 --- a/src/link/Dwarf.zig +++ b/src/link/Dwarf.zig @@ -79,6 +79,7 @@ pub const DeclState = struct { std.hash_map.default_max_load_percentage, ) = .{}, abbrev_relocs: std.ArrayListUnmanaged(AbbrevRelocation) = .{}, + exprloc_relocs: std.ArrayListUnmanaged(ExprlocRelocation) = .{}, fn init(gpa: Allocator, target: std.Target) DeclState { return .{ @@ -97,6 +98,16 @@ pub const DeclState = struct { self.abbrev_table.deinit(self.gpa); self.abbrev_resolver.deinit(self.gpa); self.abbrev_relocs.deinit(self.gpa); + self.exprloc_relocs.deinit(self.gpa); + } + + pub fn addExprlocReloc(self: *DeclState, target: u32, offset: u32, is_ptr: bool) !void { + log.debug("{x}: target sym @{d}, via GOT {}", .{ offset, target, is_ptr }); + try self.exprloc_relocs.append(self.gpa, .{ + .@"type" = if (is_ptr) .got_load else .direct_load, + .target = target, + .offset = offset, + }); } pub fn addTypeReloc( @@ -549,6 +560,18 @@ pub const AbbrevRelocation = struct { addend: u32, }; +pub const ExprlocRelocation = struct { + /// Type of the relocation: direct load ref, or GOT load ref (via GOT table) + @"type": enum { + direct_load, + got_load, + }, + /// Index of the target in the linker's locals symbol table. + target: u32, + /// Offset within the debug info buffer where to patch up the address value. + offset: u32, +}; + pub const SrcFn = struct { /// Offset from the beginning of the Debug Line Program header that contains this function. off: u32, @@ -1009,6 +1032,26 @@ pub fn commitDeclState( } } + while (decl_state.exprloc_relocs.popOrNull()) |reloc| { + switch (self.tag) { + .macho => { + const macho_file = file.cast(File.MachO).?; + const d_sym = &macho_file.d_sym.?; + try d_sym.relocs.append(d_sym.base.base.allocator, .{ + .@"type" = switch (reloc.@"type") { + .direct_load => .direct_load, + .got_load => .got_load, + }, + .target = reloc.target, + .offset = reloc.offset + atom.off, + .addend = 0, + .prev_vaddr = 0, + }); + }, + else => unreachable, + } + } + try self.writeDeclDebugInfo(file, atom, dbg_info_buffer.items); } diff --git a/src/link/MachO.zig b/src/link/MachO.zig index b193068361..d359a3fd5d 100644 --- a/src/link/MachO.zig +++ b/src/link/MachO.zig @@ -3472,6 +3472,9 @@ pub fn closeFiles(self: MachO) void { for (self.dylibs.items) |dylib| { dylib.file.close(); } + if (self.d_sym) |ds| { + ds.file.close(); + } } fn freeAtom(self: *MachO, atom: *Atom, match: MatchingSection, owns_atom: bool) void { @@ -4274,6 +4277,11 @@ pub fn freeDecl(self: *MachO, decl: *Module.Decl) void { self.got_entries_free_list.append(self.base.allocator, @intCast(u32, got_index)) catch {}; self.got_entries.items[got_index] = .{ .target = .{ .local = 0 }, .atom = undefined }; _ = self.got_entries_table.swapRemove(.{ .local = decl.link.macho.local_sym_index }); + + if (self.d_sym) |*d_sym| { + d_sym.swapRemoveRelocs(decl.link.macho.local_sym_index); + } + log.debug(" adding GOT index {d} to free list (target local@{d})", .{ got_index, decl.link.macho.local_sym_index, diff --git a/src/link/MachO/DebugSymbols.zig b/src/link/MachO/DebugSymbols.zig index 885f0ca6a8..aa7a29fcd1 100644 --- a/src/link/MachO/DebugSymbols.zig +++ b/src/link/MachO/DebugSymbols.zig @@ -59,6 +59,19 @@ debug_aranges_section_dirty: bool = false, debug_info_header_dirty: bool = false, debug_line_header_dirty: bool = false, +relocs: std.ArrayListUnmanaged(Reloc) = .{}, + +pub const Reloc = struct { + @"type": enum { + direct_load, + got_load, + }, + target: u32, + offset: u64, + addend: u32, + prev_vaddr: u64, +}; + /// You must call this function *after* `MachO.populateMissingMetadata()` /// has been called to get a viable debug symbols output. pub fn populateMissingMetadata(self: *DebugSymbols, allocator: Allocator) !void { @@ -254,6 +267,30 @@ pub fn flushModule(self: *DebugSymbols, allocator: Allocator, options: link.Opti // Zig source code. const module = options.module orelse return error.LinkingWithoutZigSourceUnimplemented; + for (self.relocs.items) |*reloc| { + const sym = switch (reloc.@"type") { + .direct_load => self.base.locals.items[reloc.target], + .got_load => blk: { + const got_index = self.base.got_entries_table.get(.{ .local = reloc.target }).?; + const got_entry = self.base.got_entries.items[got_index]; + break :blk self.base.locals.items[got_entry.atom.local_sym_index]; + }, + }; + if (sym.n_value == reloc.prev_vaddr) continue; + + const seg = &self.load_commands.items[self.dwarf_segment_cmd_index.?].segment; + const sect = &seg.sections.items[self.debug_info_section_index.?]; + const file_offset = sect.offset + reloc.offset; + log.debug("resolving relocation: {d}@{x} ('{s}') at offset {x}", .{ + reloc.target, + sym.n_value, + self.base.getString(sym.n_strx), + file_offset, + }); + try self.file.pwriteAll(mem.asBytes(&sym.n_value), file_offset); + reloc.prev_vaddr = sym.n_value; + } + if (self.debug_abbrev_section_dirty) { try self.dwarf.writeDbgAbbrev(&self.base.base); self.load_commands_dirty = true; @@ -330,7 +367,20 @@ pub fn deinit(self: *DebugSymbols, allocator: Allocator) void { } self.load_commands.deinit(allocator); self.dwarf.deinit(); - self.file.close(); + self.relocs.deinit(allocator); +} + +pub fn swapRemoveRelocs(self: *DebugSymbols, target: u32) void { + // TODO re-implement using a hashmap with free lists + var last_index: usize = 0; + while (last_index < self.relocs.items.len) { + const reloc = self.relocs.items[last_index]; + if (reloc.target == target) { + _ = self.relocs.swapRemove(last_index); + } else { + last_index += 1; + } + } } fn copySegmentCommand(