Commit 0caca625eb
Changed files (8)
lib
std
src
link
lib/std/Build/Step/CheckObject.zig
@@ -729,10 +729,10 @@ const MachODumper = struct {
imports: std.ArrayListUnmanaged([]const u8) = .empty,
fn parse(ctx: *ObjectContext) !void {
- var it = ctx.getLoadCommandIterator();
+ var it = try ctx.getLoadCommandIterator();
var i: usize = 0;
- while (it.next()) |cmd| {
- switch (cmd.cmd()) {
+ while (try it.next()) |cmd| {
+ switch (cmd.hdr.cmd) {
.SEGMENT_64 => {
const seg = cmd.cast(macho.segment_command_64).?;
try ctx.segments.append(ctx.gpa, seg);
@@ -771,14 +771,13 @@ const MachODumper = struct {
return mem.sliceTo(@as([*:0]const u8, @ptrCast(ctx.strtab.items.ptr + off)), 0);
}
- fn getLoadCommandIterator(ctx: ObjectContext) macho.LoadCommandIterator {
- const data = ctx.data[@sizeOf(macho.mach_header_64)..][0..ctx.header.sizeofcmds];
- return .{ .ncmds = ctx.header.ncmds, .buffer = data };
+ fn getLoadCommandIterator(ctx: ObjectContext) !macho.LoadCommandIterator {
+ return .init(&ctx.header, ctx.data[@sizeOf(macho.mach_header_64)..]);
}
- fn getLoadCommand(ctx: ObjectContext, cmd: macho.LC) ?macho.LoadCommandIterator.LoadCommand {
- var it = ctx.getLoadCommandIterator();
- while (it.next()) |lc| if (lc.cmd() == cmd) {
+ fn getLoadCommand(ctx: ObjectContext, cmd: macho.LC) !?macho.LoadCommandIterator.LoadCommand {
+ var it = try ctx.getLoadCommandIterator();
+ while (try it.next()) |lc| if (lc.hdr.cmd == cmd) {
return lc;
};
return null;
@@ -872,9 +871,9 @@ const MachODumper = struct {
\\LC {d}
\\cmd {s}
\\cmdsize {d}
- , .{ index, @tagName(lc.cmd()), lc.cmdsize() });
+ , .{ index, @tagName(lc.hdr.cmd), lc.hdr.cmdsize });
- switch (lc.cmd()) {
+ switch (lc.hdr.cmd) {
.SEGMENT_64 => {
const seg = lc.cast(macho.segment_command_64).?;
try writer.writeByte('\n');
@@ -1592,9 +1591,9 @@ const MachODumper = struct {
.headers => {
try ObjectContext.dumpHeader(ctx.header, writer);
- var it = ctx.getLoadCommandIterator();
+ var it = try ctx.getLoadCommandIterator();
var i: usize = 0;
- while (it.next()) |cmd| {
+ while (try it.next()) |cmd| {
try ObjectContext.dumpLoadCommand(cmd, i, writer);
try writer.writeByte('\n');
@@ -1615,7 +1614,7 @@ const MachODumper = struct {
.dyld_weak_bind,
.dyld_lazy_bind,
=> {
- const cmd = ctx.getLoadCommand(.DYLD_INFO_ONLY) orelse
+ const cmd = try ctx.getLoadCommand(.DYLD_INFO_ONLY) orelse
return step.fail("no dyld info found", .{});
const lc = cmd.cast(macho.dyld_info_command).?;
@@ -1649,7 +1648,7 @@ const MachODumper = struct {
},
.exports => blk: {
- if (ctx.getLoadCommand(.DYLD_INFO_ONLY)) |cmd| {
+ if (try ctx.getLoadCommand(.DYLD_INFO_ONLY)) |cmd| {
const lc = cmd.cast(macho.dyld_info_command).?;
if (lc.export_size > 0) {
const data = ctx.data[lc.export_off..][0..lc.export_size];
lib/std/debug/SelfInfo/MachO.zig
@@ -1,12 +1,10 @@
mutex: std.Thread.Mutex,
/// Accessed through `Module.Adapter`.
modules: std.ArrayHashMapUnmanaged(Module, void, Module.Context, false),
-ofiles: std.StringArrayHashMapUnmanaged(?OFile),
pub const init: SelfInfo = .{
.mutex = .{},
.modules = .empty,
- .ofiles = .empty,
};
pub fn deinit(si: *SelfInfo, gpa: Allocator) void {
for (si.modules.keys()) |*module| {
@@ -14,20 +12,12 @@ pub fn deinit(si: *SelfInfo, gpa: Allocator) void {
const u = &(module.unwind orelse break :unwind catch break :unwind);
if (u.dwarf) |*dwarf| dwarf.deinit(gpa);
}
- loaded: {
- const l = &(module.loaded_macho orelse break :loaded catch break :loaded);
- gpa.free(l.symbols);
- posix.munmap(l.mapped_memory);
+ file: {
+ const f = &(module.file orelse break :file catch break :file);
+ f.deinit(gpa);
}
}
- for (si.ofiles.values()) |*opt_ofile| {
- const ofile = &(opt_ofile.* orelse continue);
- ofile.dwarf.deinit(gpa);
- ofile.symbols_by_name.deinit(gpa);
- posix.munmap(ofile.mapped_memory);
- }
si.modules.deinit(gpa);
- si.ofiles.deinit(gpa);
}
pub fn getSymbol(si: *SelfInfo, gpa: Allocator, io: Io, address: usize) Error!std.debug.Symbol {
@@ -35,67 +25,55 @@ pub fn getSymbol(si: *SelfInfo, gpa: Allocator, io: Io, address: usize) Error!st
const module = try si.findModule(gpa, address);
defer si.mutex.unlock();
- const loaded_macho = try module.getLoadedMachO(gpa);
-
- const vaddr = address - loaded_macho.vaddr_offset;
- const symbol = MachoSymbol.find(loaded_macho.symbols, vaddr) orelse return .unknown;
+ const file = try module.getFile(gpa);
- // offset of `address` from start of `symbol`
- const address_symbol_offset = vaddr - symbol.addr;
+ // This is not necessarily the same as the vmaddr_slide that dyld would report. This is
+ // because the segments in the file on disk might differ from the ones in memory. Normally
+ // we wouldn't necessarily expect that to work, but /usr/lib/dyld is incredibly annoying:
+ // it exists on disk (necessarily, because the kernel needs to load it!), but is also in
+ // the dyld cache (dyld actually restart itself from cache after loading it), and the two
+ // versions have (very) different segment base addresses. It's sort of like a large slide
+ // has been applied to all addresses in memory. For an optimal experience, we consider the
+ // on-disk vmaddr instead of the in-memory one.
+ const vaddr_offset = module.text_base - file.text_vmaddr;
- // Take the symbol name from the N_FUN STAB entry, we're going to
- // use it if we fail to find the DWARF infos
- const stab_symbol = mem.sliceTo(loaded_macho.strings[symbol.strx..], 0);
+ const vaddr = address - vaddr_offset;
- // If any information is missing, we can at least return this from now on.
- const sym_only_result: std.debug.Symbol = .{
- .name = stab_symbol,
- .compile_unit_name = null,
- .source_location = null,
+ const ofile_dwarf, const ofile_vaddr = file.getDwarfForAddress(gpa, vaddr) catch {
+ // Return at least the symbol name if available.
+ return .{
+ .name = try file.lookupSymbolName(vaddr),
+ .compile_unit_name = null,
+ .source_location = null,
+ };
};
- if (symbol.ofile == MachoSymbol.unknown_ofile) {
- // We don't have STAB info, so can't track down the object file; all we can do is the symbol name.
- return sym_only_result;
- }
-
- const o_file: *OFile = of: {
- const path = mem.sliceTo(loaded_macho.strings[symbol.ofile..], 0);
- const gop = try si.ofiles.getOrPut(gpa, path);
- if (!gop.found_existing) {
- gop.value_ptr.* = loadOFile(gpa, path) catch null;
- }
- if (gop.value_ptr.*) |*o_file| {
- break :of o_file;
- } else {
- return sym_only_result;
- }
+ const compile_unit = ofile_dwarf.findCompileUnit(native_endian, ofile_vaddr) catch {
+ // Return at least the symbol name if available.
+ return .{
+ .name = try file.lookupSymbolName(vaddr),
+ .compile_unit_name = null,
+ .source_location = null,
+ };
};
- const symbol_index = o_file.symbols_by_name.getKeyAdapted(
- @as([]const u8, stab_symbol),
- @as(OFile.SymbolAdapter, .{ .strtab = o_file.strtab, .symtab = o_file.symtab }),
- ) orelse return sym_only_result;
- const symbol_ofile_vaddr = o_file.symtab[symbol_index].n_value;
-
- const compile_unit = o_file.dwarf.findCompileUnit(native_endian, symbol_ofile_vaddr) catch return sym_only_result;
-
return .{
- .name = o_file.dwarf.getSymbolName(symbol_ofile_vaddr + address_symbol_offset) orelse stab_symbol,
+ .name = ofile_dwarf.getSymbolName(ofile_vaddr) orelse
+ try file.lookupSymbolName(vaddr),
.compile_unit_name = compile_unit.die.getAttrString(
- &o_file.dwarf,
+ ofile_dwarf,
native_endian,
std.dwarf.AT.name,
- o_file.dwarf.section(.debug_str),
+ ofile_dwarf.section(.debug_str),
compile_unit,
) catch |err| switch (err) {
error.MissingDebugInfo, error.InvalidDebugInfo => null,
},
- .source_location = o_file.dwarf.getLineNumberInfo(
+ .source_location = ofile_dwarf.getLineNumberInfo(
gpa,
native_endian,
compile_unit,
- symbol_ofile_vaddr + address_symbol_offset,
+ ofile_vaddr,
) catch null,
};
}
@@ -447,7 +425,7 @@ fn findModule(si: *SelfInfo, gpa: Allocator, address: usize) Error!*Module {
.text_base = @intFromPtr(info.fbase),
.name = std.mem.span(info.fname),
.unwind = null,
- .loaded_macho = null,
+ .file = null,
};
}
return gop.key_ptr;
@@ -457,7 +435,7 @@ const Module = struct {
text_base: usize,
name: []const u8,
unwind: ?(Error!Unwind),
- loaded_macho: ?(Error!LoadedMachO),
+ file: ?(Error!MachOFile),
const Adapter = struct {
pub fn hash(_: Adapter, text_base: usize) u32 {
@@ -488,34 +466,17 @@ const Module = struct {
dwarf: ?Dwarf.Unwind,
};
- const LoadedMachO = struct {
- mapped_memory: []align(std.heap.page_size_min) const u8,
- symbols: []const MachoSymbol,
- strings: []const u8,
- /// This is not necessarily the same as the vmaddr_slide that dyld would report. This is
- /// because the segments in the file on disk might differ from the ones in memory. Normally
- /// we wouldn't necessarily expect that to work, but /usr/lib/dyld is incredibly annoying:
- /// it exists on disk (necessarily, because the kernel needs to load it!), but is also in
- /// the dyld cache (dyld actually restart itself from cache after loading it), and the two
- /// versions have (very) different segment base addresses. It's sort of like a large slide
- /// has been applied to all addresses in memory. For an optimal experience, we consider the
- /// on-disk vmaddr instead of the in-memory one.
- vaddr_offset: usize,
- };
-
fn getUnwindInfo(module: *Module, gpa: Allocator) Error!*Unwind {
if (module.unwind == null) module.unwind = loadUnwindInfo(module, gpa);
return if (module.unwind.?) |*unwind| unwind else |err| err;
}
fn loadUnwindInfo(module: *const Module, gpa: Allocator) Error!Unwind {
- const header: *std.macho.mach_header = @ptrFromInt(module.text_base);
+ const header: *std.macho.mach_header_64 = @ptrFromInt(module.text_base);
- var it: macho.LoadCommandIterator = .{
- .ncmds = header.ncmds,
- .buffer = @as([*]u8, @ptrCast(header))[@sizeOf(macho.mach_header_64)..][0..header.sizeofcmds],
- };
- const sections, const text_vmaddr = while (it.next()) |load_cmd| {
- if (load_cmd.cmd() != .SEGMENT_64) continue;
+ const raw_macho: [*]u8 = @ptrCast(header);
+ var it = macho.LoadCommandIterator.init(header, raw_macho[@sizeOf(macho.mach_header_64)..][0..header.sizeofcmds]) catch unreachable;
+ const sections, const text_vmaddr = while (it.next() catch unreachable) |load_cmd| {
+ if (load_cmd.hdr.cmd != .SEGMENT_64) continue;
const segment_cmd = load_cmd.cast(macho.segment_command_64).?;
if (!mem.eql(u8, segment_cmd.segName(), "__TEXT")) continue;
break .{ load_cmd.getSections(), segment_cmd.vmaddr };
@@ -568,237 +529,15 @@ const Module = struct {
};
}
- fn getLoadedMachO(module: *Module, gpa: Allocator) Error!*LoadedMachO {
- if (module.loaded_macho == null) module.loaded_macho = loadMachO(module, gpa) catch |err| switch (err) {
- error.InvalidDebugInfo, error.MissingDebugInfo, error.OutOfMemory, error.Unexpected => |e| e,
- else => error.ReadFailed,
- };
- return if (module.loaded_macho.?) |*lm| lm else |err| err;
- }
- fn loadMachO(module: *const Module, gpa: Allocator) Error!LoadedMachO {
- const all_mapped_memory = try mapDebugInfoFile(module.name);
- errdefer posix.munmap(all_mapped_memory);
-
- // In most cases, the file we just mapped is a Mach-O binary. However, it could be a "universal
- // binary": a simple file format which contains Mach-O binaries for multiple targets. For
- // instance, `/usr/lib/dyld` is currently distributed as a universal binary containing images
- // for both ARM64 macOS and x86_64 macOS.
- if (all_mapped_memory.len < 4) return error.InvalidDebugInfo;
- const magic = @as(*const u32, @ptrCast(all_mapped_memory.ptr)).*;
- // The contents of a Mach-O file, which may or may not be the whole of `all_mapped_memory`.
- const mapped_macho = switch (magic) {
- macho.MH_MAGIC_64 => all_mapped_memory,
-
- macho.FAT_CIGAM => mapped_macho: {
- // This is the universal binary format (aka a "fat binary"). Annoyingly, the whole thing
- // is big-endian, so we'll be swapping some bytes.
- if (all_mapped_memory.len < @sizeOf(macho.fat_header)) return error.InvalidDebugInfo;
- const hdr: *const macho.fat_header = @ptrCast(all_mapped_memory.ptr);
- const archs_ptr: [*]const macho.fat_arch = @ptrCast(all_mapped_memory.ptr + @sizeOf(macho.fat_header));
- const archs: []const macho.fat_arch = archs_ptr[0..@byteSwap(hdr.nfat_arch)];
- const native_cpu_type = switch (builtin.cpu.arch) {
- .x86_64 => macho.CPU_TYPE_X86_64,
- .aarch64 => macho.CPU_TYPE_ARM64,
- else => comptime unreachable,
- };
- for (archs) |*arch| {
- if (@byteSwap(arch.cputype) != native_cpu_type) continue;
- const offset = @byteSwap(arch.offset);
- const size = @byteSwap(arch.size);
- break :mapped_macho all_mapped_memory[offset..][0..size];
- }
- // Our native architecture was not present in the fat binary.
- return error.MissingDebugInfo;
- },
-
- // Even on modern 64-bit targets, this format doesn't seem to be too extensively used. It
- // will be fairly easy to add support here if necessary; it's very similar to above.
- macho.FAT_CIGAM_64 => return error.UnsupportedDebugInfo,
-
- else => return error.InvalidDebugInfo,
- };
-
- const hdr: *const macho.mach_header_64 = @ptrCast(@alignCast(mapped_macho.ptr));
- if (hdr.magic != macho.MH_MAGIC_64)
- return error.InvalidDebugInfo;
-
- const symtab: macho.symtab_command, const text_vmaddr: u64 = lc_iter: {
- var it: macho.LoadCommandIterator = .{
- .ncmds = hdr.ncmds,
- .buffer = mapped_macho[@sizeOf(macho.mach_header_64)..][0..hdr.sizeofcmds],
- };
- var symtab: ?macho.symtab_command = null;
- var text_vmaddr: ?u64 = null;
- while (it.next()) |cmd| switch (cmd.cmd()) {
- .SYMTAB => symtab = cmd.cast(macho.symtab_command) orelse return error.InvalidDebugInfo,
- .SEGMENT_64 => if (cmd.cast(macho.segment_command_64)) |seg_cmd| {
- if (!mem.eql(u8, seg_cmd.segName(), "__TEXT")) continue;
- text_vmaddr = seg_cmd.vmaddr;
- },
- else => {},
- };
- break :lc_iter .{
- symtab orelse return error.MissingDebugInfo,
- text_vmaddr orelse return error.MissingDebugInfo,
- };
- };
-
- const syms_ptr: [*]align(1) const macho.nlist_64 = @ptrCast(mapped_macho[symtab.symoff..]);
- const syms = syms_ptr[0..symtab.nsyms];
- const strings = mapped_macho[symtab.stroff..][0 .. symtab.strsize - 1];
-
- var symbols: std.ArrayList(MachoSymbol) = try .initCapacity(gpa, syms.len);
- defer symbols.deinit(gpa);
-
- // This map is temporary; it is used only to detect duplicates here. This is
- // necessary because we prefer to use STAB ("symbolic debugging table") symbols,
- // but they might not be present, so we track normal symbols too.
- // Indices match 1-1 with those of `symbols`.
- var symbol_names: std.StringArrayHashMapUnmanaged(void) = .empty;
- defer symbol_names.deinit(gpa);
- try symbol_names.ensureUnusedCapacity(gpa, syms.len);
-
- var ofile: u32 = undefined;
- var last_sym: MachoSymbol = undefined;
- var state: enum {
- init,
- oso_open,
- oso_close,
- bnsym,
- fun_strx,
- fun_size,
- ensym,
- } = .init;
-
- for (syms) |*sym| {
- if (sym.n_type.bits.is_stab == 0) {
- if (sym.n_strx == 0) continue;
- switch (sym.n_type.bits.type) {
- .undf, .pbud, .indr, .abs, _ => continue,
- .sect => {
- const name = std.mem.sliceTo(strings[sym.n_strx..], 0);
- const gop = symbol_names.getOrPutAssumeCapacity(name);
- if (!gop.found_existing) {
- assert(gop.index == symbols.items.len);
- symbols.appendAssumeCapacity(.{
- .strx = sym.n_strx,
- .addr = sym.n_value,
- .ofile = MachoSymbol.unknown_ofile,
- });
- }
- },
- }
- continue;
- }
-
- // TODO handle globals N_GSYM, and statics N_STSYM
- switch (sym.n_type.stab) {
- .oso => switch (state) {
- .init, .oso_close => {
- state = .oso_open;
- ofile = sym.n_strx;
- },
- else => return error.InvalidDebugInfo,
- },
- .bnsym => switch (state) {
- .oso_open, .ensym => {
- state = .bnsym;
- last_sym = .{
- .strx = 0,
- .addr = sym.n_value,
- .ofile = ofile,
- };
- },
- else => return error.InvalidDebugInfo,
- },
- .fun => switch (state) {
- .bnsym => {
- state = .fun_strx;
- last_sym.strx = sym.n_strx;
- },
- .fun_strx => {
- state = .fun_size;
- },
- else => return error.InvalidDebugInfo,
- },
- .ensym => switch (state) {
- .fun_size => {
- state = .ensym;
- if (last_sym.strx != 0) {
- const name = std.mem.sliceTo(strings[last_sym.strx..], 0);
- const gop = symbol_names.getOrPutAssumeCapacity(name);
- if (!gop.found_existing) {
- assert(gop.index == symbols.items.len);
- symbols.appendAssumeCapacity(last_sym);
- } else {
- symbols.items[gop.index] = last_sym;
- }
- }
- },
- else => return error.InvalidDebugInfo,
- },
- .so => switch (state) {
- .init, .oso_close => {},
- .oso_open, .ensym => {
- state = .oso_close;
- },
- else => return error.InvalidDebugInfo,
- },
- else => {},
- }
- }
-
- switch (state) {
- .init => {
- // Missing STAB symtab entries is still okay, unless there were also no normal symbols.
- if (symbols.items.len == 0) return error.MissingDebugInfo;
- },
- .oso_close => {},
- else => return error.InvalidDebugInfo, // corrupted STAB entries in symtab
- }
-
- const symbols_slice = try symbols.toOwnedSlice(gpa);
- errdefer gpa.free(symbols_slice);
-
- // Even though lld emits symbols in ascending order, this debug code
- // should work for programs linked in any valid way.
- // This sort is so that we can binary search later.
- mem.sort(MachoSymbol, symbols_slice, {}, MachoSymbol.addressLessThan);
-
- return .{
- .mapped_memory = all_mapped_memory,
- .symbols = symbols_slice,
- .strings = strings,
- .vaddr_offset = module.text_base - text_vmaddr,
+ fn getFile(module: *Module, gpa: Allocator) Error!*MachOFile {
+ if (module.file == null) module.file = MachOFile.load(gpa, module.name, builtin.cpu.arch) catch |err| switch (err) {
+ error.InvalidMachO, error.InvalidDwarf => error.InvalidDebugInfo,
+ error.MissingDebugInfo, error.OutOfMemory, error.UnsupportedDebugInfo, error.ReadFailed => |e| e,
};
+ return if (module.file.?) |*f| f else |err| err;
}
};
-const OFile = struct {
- mapped_memory: []align(std.heap.page_size_min) const u8,
- dwarf: Dwarf,
- strtab: []const u8,
- symtab: []align(1) const macho.nlist_64,
- /// All named symbols in `symtab`. Stored `u32` key is the index into `symtab`. Accessed
- /// through `SymbolAdapter`, so that the symbol name is used as the logical key.
- symbols_by_name: std.ArrayHashMapUnmanaged(u32, void, void, true),
-
- const SymbolAdapter = struct {
- strtab: []const u8,
- symtab: []align(1) const macho.nlist_64,
- pub fn hash(ctx: SymbolAdapter, sym_name: []const u8) u32 {
- _ = ctx;
- return @truncate(std.hash.Wyhash.hash(0, sym_name));
- }
- pub fn eql(ctx: SymbolAdapter, a_sym_name: []const u8, b_sym_index: u32, b_index: usize) bool {
- _ = b_index;
- const b_sym = ctx.symtab[b_sym_index];
- const b_sym_name = std.mem.sliceTo(ctx.strtab[b_sym.n_strx..], 0);
- return mem.eql(u8, a_sym_name, b_sym_name);
- }
- };
-};
-
const MachoSymbol = struct {
strx: u32,
addr: u64,
@@ -880,101 +619,12 @@ fn mapDebugInfoFile(path: []const u8) ![]align(std.heap.page_size_min) const u8
};
}
-fn loadOFile(gpa: Allocator, o_file_path: []const u8) !OFile {
- const mapped_mem = try mapDebugInfoFile(o_file_path);
- errdefer posix.munmap(mapped_mem);
-
- if (mapped_mem.len < @sizeOf(macho.mach_header_64)) return error.InvalidDebugInfo;
- const hdr: *const macho.mach_header_64 = @ptrCast(@alignCast(mapped_mem.ptr));
- if (hdr.magic != std.macho.MH_MAGIC_64) return error.InvalidDebugInfo;
-
- const seg_cmd: macho.LoadCommandIterator.LoadCommand, const symtab_cmd: macho.symtab_command = cmds: {
- var seg_cmd: ?macho.LoadCommandIterator.LoadCommand = null;
- var symtab_cmd: ?macho.symtab_command = null;
- var it: macho.LoadCommandIterator = .{
- .ncmds = hdr.ncmds,
- .buffer = mapped_mem[@sizeOf(macho.mach_header_64)..][0..hdr.sizeofcmds],
- };
- while (it.next()) |cmd| switch (cmd.cmd()) {
- .SEGMENT_64 => seg_cmd = cmd,
- .SYMTAB => symtab_cmd = cmd.cast(macho.symtab_command) orelse return error.InvalidDebugInfo,
- else => {},
- };
- break :cmds .{
- seg_cmd orelse return error.MissingDebugInfo,
- symtab_cmd orelse return error.MissingDebugInfo,
- };
- };
-
- if (mapped_mem.len < symtab_cmd.stroff + symtab_cmd.strsize) return error.InvalidDebugInfo;
- if (mapped_mem[symtab_cmd.stroff + symtab_cmd.strsize - 1] != 0) return error.InvalidDebugInfo;
- const strtab = mapped_mem[symtab_cmd.stroff..][0 .. symtab_cmd.strsize - 1];
-
- const n_sym_bytes = symtab_cmd.nsyms * @sizeOf(macho.nlist_64);
- if (mapped_mem.len < symtab_cmd.symoff + n_sym_bytes) return error.InvalidDebugInfo;
- const symtab: []align(1) const macho.nlist_64 = @ptrCast(mapped_mem[symtab_cmd.symoff..][0..n_sym_bytes]);
-
- // TODO handle tentative (common) symbols
- var symbols_by_name: std.ArrayHashMapUnmanaged(u32, void, void, true) = .empty;
- defer symbols_by_name.deinit(gpa);
- try symbols_by_name.ensureUnusedCapacity(gpa, @intCast(symtab.len));
- for (symtab, 0..) |sym, sym_index| {
- if (sym.n_strx == 0) continue;
- switch (sym.n_type.bits.type) {
- .undf => continue, // includes tentative symbols
- .abs => continue,
- else => {},
- }
- const sym_name = mem.sliceTo(strtab[sym.n_strx..], 0);
- const gop = symbols_by_name.getOrPutAssumeCapacityAdapted(
- @as([]const u8, sym_name),
- @as(OFile.SymbolAdapter, .{ .strtab = strtab, .symtab = symtab }),
- );
- if (gop.found_existing) return error.InvalidDebugInfo;
- gop.key_ptr.* = @intCast(sym_index);
- }
-
- var sections: Dwarf.SectionArray = @splat(null);
- for (seg_cmd.getSections()) |sect| {
- if (!std.mem.eql(u8, "__DWARF", sect.segName())) continue;
-
- const section_index: usize = inline for (@typeInfo(Dwarf.Section.Id).@"enum".fields, 0..) |section, i| {
- if (mem.eql(u8, "__" ++ section.name, sect.sectName())) break i;
- } else continue;
-
- if (mapped_mem.len < sect.offset + sect.size) return error.InvalidDebugInfo;
- const section_bytes = mapped_mem[sect.offset..][0..sect.size];
- sections[section_index] = .{
- .data = section_bytes,
- .owned = false,
- };
- }
-
- const missing_debug_info =
- sections[@intFromEnum(Dwarf.Section.Id.debug_info)] == null or
- sections[@intFromEnum(Dwarf.Section.Id.debug_abbrev)] == null or
- sections[@intFromEnum(Dwarf.Section.Id.debug_str)] == null or
- sections[@intFromEnum(Dwarf.Section.Id.debug_line)] == null;
- if (missing_debug_info) return error.MissingDebugInfo;
-
- var dwarf: Dwarf = .{ .sections = sections };
- errdefer dwarf.deinit(gpa);
- try dwarf.open(gpa, native_endian);
-
- return .{
- .mapped_memory = mapped_mem,
- .dwarf = dwarf,
- .strtab = strtab,
- .symtab = symtab,
- .symbols_by_name = symbols_by_name.move(),
- };
-}
-
const std = @import("std");
const Io = std.Io;
const Allocator = std.mem.Allocator;
const Dwarf = std.debug.Dwarf;
const Error = std.debug.SelfInfoError;
+const MachOFile = std.debug.MachOFile;
const assert = std.debug.assert;
const posix = std.posix;
const macho = std.macho;
lib/std/debug/MachOFile.zig
@@ -0,0 +1,501 @@
+mapped_memory: []align(std.heap.page_size_min) const u8,
+symbols: []const Symbol,
+strings: []const u8,
+text_vmaddr: u64,
+
+/// Key is index into `strings` of the file path.
+ofiles: std.AutoArrayHashMapUnmanaged(u32, Error!OFile),
+
+pub const Error = error{
+ InvalidMachO,
+ InvalidDwarf,
+ MissingDebugInfo,
+ UnsupportedDebugInfo,
+ ReadFailed,
+ OutOfMemory,
+};
+
+pub fn deinit(mf: *MachOFile, gpa: Allocator) void {
+ for (mf.ofiles.values()) |*maybe_of| {
+ const of = &(maybe_of.* catch continue);
+ posix.munmap(of.mapped_memory);
+ of.dwarf.deinit(gpa);
+ of.symbols_by_name.deinit(gpa);
+ }
+ mf.ofiles.deinit(gpa);
+ gpa.free(mf.symbols);
+ posix.munmap(mf.mapped_memory);
+}
+
+pub fn load(gpa: Allocator, path: []const u8, arch: std.Target.Cpu.Arch) Error!MachOFile {
+ switch (arch) {
+ .x86_64, .aarch64 => {},
+ else => unreachable,
+ }
+
+ const all_mapped_memory = try mapDebugInfoFile(path);
+ errdefer posix.munmap(all_mapped_memory);
+
+ // In most cases, the file we just mapped is a Mach-O binary. However, it could be a "universal
+ // binary": a simple file format which contains Mach-O binaries for multiple targets. For
+ // instance, `/usr/lib/dyld` is currently distributed as a universal binary containing images
+ // for both ARM64 macOS and x86_64 macOS.
+ if (all_mapped_memory.len < 4) return error.InvalidMachO;
+ const magic = std.mem.readInt(u32, all_mapped_memory.ptr[0..4], .little);
+
+ // The contents of a Mach-O file, which may or may not be the whole of `all_mapped_memory`.
+ const mapped_macho = switch (magic) {
+ macho.MH_MAGIC_64 => all_mapped_memory,
+
+ macho.FAT_CIGAM => mapped_macho: {
+ // This is the universal binary format (aka a "fat binary").
+ var fat_r: Io.Reader = .fixed(all_mapped_memory);
+ const hdr = fat_r.takeStruct(macho.fat_header, .big) catch |err| switch (err) {
+ error.ReadFailed => unreachable,
+ error.EndOfStream => return error.InvalidMachO,
+ };
+ const want_cpu_type = switch (arch) {
+ .x86_64 => macho.CPU_TYPE_X86_64,
+ .aarch64 => macho.CPU_TYPE_ARM64,
+ else => unreachable,
+ };
+ for (0..hdr.nfat_arch) |_| {
+ const fat_arch = fat_r.takeStruct(macho.fat_arch, .big) catch |err| switch (err) {
+ error.ReadFailed => unreachable,
+ error.EndOfStream => return error.InvalidMachO,
+ };
+ if (fat_arch.cputype != want_cpu_type) continue;
+ if (fat_arch.offset + fat_arch.size > all_mapped_memory.len) return error.InvalidMachO;
+ break :mapped_macho all_mapped_memory[fat_arch.offset..][0..fat_arch.size];
+ }
+ // `arch` was not present in the fat binary.
+ return error.MissingDebugInfo;
+ },
+
+ // Even on modern 64-bit targets, this format doesn't seem to be too extensively used. It
+ // will be fairly easy to add support here if necessary; it's very similar to above.
+ macho.FAT_CIGAM_64 => return error.UnsupportedDebugInfo,
+
+ else => return error.InvalidMachO,
+ };
+
+ var r: Io.Reader = .fixed(mapped_macho);
+ const hdr = r.takeStruct(macho.mach_header_64, .little) catch |err| switch (err) {
+ error.ReadFailed => unreachable,
+ error.EndOfStream => return error.InvalidMachO,
+ };
+
+ if (hdr.magic != macho.MH_MAGIC_64)
+ return error.InvalidMachO;
+
+ const symtab: macho.symtab_command, const text_vmaddr: u64 = lcs: {
+ var it: macho.LoadCommandIterator = try .init(&hdr, mapped_macho[@sizeOf(macho.mach_header_64)..]);
+ var symtab: ?macho.symtab_command = null;
+ var text_vmaddr: ?u64 = null;
+ while (try it.next()) |cmd| switch (cmd.hdr.cmd) {
+ .SYMTAB => symtab = cmd.cast(macho.symtab_command) orelse return error.InvalidMachO,
+ .SEGMENT_64 => if (cmd.cast(macho.segment_command_64)) |seg_cmd| {
+ if (!mem.eql(u8, seg_cmd.segName(), "__TEXT")) continue;
+ text_vmaddr = seg_cmd.vmaddr;
+ },
+ else => {},
+ };
+ break :lcs .{
+ symtab orelse return error.MissingDebugInfo,
+ text_vmaddr orelse return error.MissingDebugInfo,
+ };
+ };
+
+ const strings = mapped_macho[symtab.stroff..][0 .. symtab.strsize - 1];
+
+ var symbols: std.ArrayList(Symbol) = try .initCapacity(gpa, symtab.nsyms);
+ defer symbols.deinit(gpa);
+
+ // This map is temporary; it is used only to detect duplicates here. This is
+ // necessary because we prefer to use STAB ("symbolic debugging table") symbols,
+ // but they might not be present, so we track normal symbols too.
+ // Indices match 1-1 with those of `symbols`.
+ var symbol_names: std.StringArrayHashMapUnmanaged(void) = .empty;
+ defer symbol_names.deinit(gpa);
+ try symbol_names.ensureUnusedCapacity(gpa, symtab.nsyms);
+
+ var ofile: u32 = undefined;
+ var last_sym: Symbol = undefined;
+ var state: enum {
+ init,
+ oso_open,
+ oso_close,
+ bnsym,
+ fun_strx,
+ fun_size,
+ ensym,
+ } = .init;
+
+ var sym_r: Io.Reader = .fixed(mapped_macho[symtab.symoff..]);
+ for (0..symtab.nsyms) |_| {
+ const sym = sym_r.takeStruct(macho.nlist_64, .little) catch |err| switch (err) {
+ error.ReadFailed => unreachable,
+ error.EndOfStream => return error.InvalidMachO,
+ };
+ if (sym.n_type.bits.is_stab == 0) {
+ if (sym.n_strx == 0) continue;
+ switch (sym.n_type.bits.type) {
+ .undf, .pbud, .indr, .abs, _ => continue,
+ .sect => {
+ const name = std.mem.sliceTo(strings[sym.n_strx..], 0);
+ const gop = symbol_names.getOrPutAssumeCapacity(name);
+ if (!gop.found_existing) {
+ assert(gop.index == symbols.items.len);
+ symbols.appendAssumeCapacity(.{
+ .strx = sym.n_strx,
+ .addr = sym.n_value,
+ .ofile = Symbol.unknown_ofile,
+ });
+ }
+ },
+ }
+ continue;
+ }
+
+ // TODO handle globals N_GSYM, and statics N_STSYM
+ switch (sym.n_type.stab) {
+ .oso => switch (state) {
+ .init, .oso_close => {
+ state = .oso_open;
+ ofile = sym.n_strx;
+ },
+ else => return error.InvalidMachO,
+ },
+ .bnsym => switch (state) {
+ .oso_open, .ensym => {
+ state = .bnsym;
+ last_sym = .{
+ .strx = 0,
+ .addr = sym.n_value,
+ .ofile = ofile,
+ };
+ },
+ else => return error.InvalidMachO,
+ },
+ .fun => switch (state) {
+ .bnsym => {
+ state = .fun_strx;
+ last_sym.strx = sym.n_strx;
+ },
+ .fun_strx => {
+ state = .fun_size;
+ },
+ else => return error.InvalidMachO,
+ },
+ .ensym => switch (state) {
+ .fun_size => {
+ state = .ensym;
+ if (last_sym.strx != 0) {
+ const name = std.mem.sliceTo(strings[last_sym.strx..], 0);
+ const gop = symbol_names.getOrPutAssumeCapacity(name);
+ if (!gop.found_existing) {
+ assert(gop.index == symbols.items.len);
+ symbols.appendAssumeCapacity(last_sym);
+ } else {
+ symbols.items[gop.index] = last_sym;
+ }
+ }
+ },
+ else => return error.InvalidMachO,
+ },
+ .so => switch (state) {
+ .init, .oso_close => {},
+ .oso_open, .ensym => {
+ state = .oso_close;
+ },
+ else => return error.InvalidMachO,
+ },
+ else => {},
+ }
+ }
+
+ switch (state) {
+ .init => {
+ // Missing STAB symtab entries is still okay, unless there were also no normal symbols.
+ if (symbols.items.len == 0) return error.MissingDebugInfo;
+ },
+ .oso_close => {},
+ else => return error.InvalidMachO, // corrupted STAB entries in symtab
+ }
+
+ const symbols_slice = try symbols.toOwnedSlice(gpa);
+ errdefer gpa.free(symbols_slice);
+
+ // Even though lld emits symbols in ascending order, this debug code
+ // should work for programs linked in any valid way.
+ // This sort is so that we can binary search later.
+ mem.sort(Symbol, symbols_slice, {}, Symbol.addressLessThan);
+
+ return .{
+ .mapped_memory = all_mapped_memory,
+ .symbols = symbols_slice,
+ .strings = strings,
+ .ofiles = .empty,
+ .text_vmaddr = text_vmaddr,
+ };
+}
+pub fn getDwarfForAddress(mf: *MachOFile, gpa: Allocator, vaddr: u64) !struct { *Dwarf, u64 } {
+ const symbol = Symbol.find(mf.symbols, vaddr) orelse return error.MissingDebugInfo;
+
+ if (symbol.ofile == Symbol.unknown_ofile) return error.MissingDebugInfo;
+
+ // offset of `address` from start of `symbol`
+ const address_symbol_offset = vaddr - symbol.addr;
+
+ // Take the symbol name from the N_FUN STAB entry, we're going to
+ // use it if we fail to find the DWARF infos
+ const stab_symbol = mem.sliceTo(mf.strings[symbol.strx..], 0);
+
+ const gop = try mf.ofiles.getOrPut(gpa, symbol.ofile);
+ if (!gop.found_existing) {
+ const name = mem.sliceTo(mf.strings[symbol.ofile..], 0);
+ gop.value_ptr.* = loadOFile(gpa, name);
+ }
+ const of = &(gop.value_ptr.* catch |err| return err);
+
+ const symbol_index = of.symbols_by_name.getKeyAdapted(
+ @as([]const u8, stab_symbol),
+ @as(OFile.SymbolAdapter, .{ .strtab = of.strtab, .symtab_raw = of.symtab_raw }),
+ ) orelse return error.MissingDebugInfo;
+
+ const symbol_ofile_vaddr = vaddr: {
+ var sym = of.symtab_raw[symbol_index];
+ if (builtin.cpu.arch.endian() != .little) std.mem.byteSwapAllFields(macho.nlist_64, &sym);
+ break :vaddr sym.n_value;
+ };
+
+ return .{ &of.dwarf, symbol_ofile_vaddr + address_symbol_offset };
+}
+pub fn lookupSymbolName(mf: *MachOFile, vaddr: u64) error{MissingDebugInfo}![]const u8 {
+ const symbol = Symbol.find(mf.symbols, vaddr) orelse return error.MissingDebugInfo;
+ return mem.sliceTo(mf.strings[symbol.strx..], 0);
+}
+
+const OFile = struct {
+ mapped_memory: []align(std.heap.page_size_min) const u8,
+ dwarf: Dwarf,
+ strtab: []const u8,
+ symtab_raw: []align(1) const macho.nlist_64,
+ /// All named symbols in `symtab_raw`. Stored `u32` key is the index into `symtab_raw`. Accessed
+ /// through `SymbolAdapter`, so that the symbol name is used as the logical key.
+ symbols_by_name: std.ArrayHashMapUnmanaged(u32, void, void, true),
+
+ const SymbolAdapter = struct {
+ strtab: []const u8,
+ symtab_raw: []align(1) const macho.nlist_64,
+ pub fn hash(ctx: SymbolAdapter, sym_name: []const u8) u32 {
+ _ = ctx;
+ return @truncate(std.hash.Wyhash.hash(0, sym_name));
+ }
+ pub fn eql(ctx: SymbolAdapter, a_sym_name: []const u8, b_sym_index: u32, b_index: usize) bool {
+ _ = b_index;
+ var b_sym = ctx.symtab_raw[b_sym_index];
+ if (builtin.cpu.arch.endian() != .little) std.mem.byteSwapAllFields(macho.nlist_64, &b_sym);
+ const b_sym_name = std.mem.sliceTo(ctx.strtab[b_sym.n_strx..], 0);
+ return mem.eql(u8, a_sym_name, b_sym_name);
+ }
+ };
+};
+
+const Symbol = struct {
+ strx: u32,
+ addr: u64,
+ /// Value may be `unknown_ofile`.
+ ofile: u32,
+ const unknown_ofile = std.math.maxInt(u32);
+ fn addressLessThan(context: void, lhs: Symbol, rhs: Symbol) bool {
+ _ = context;
+ return lhs.addr < rhs.addr;
+ }
+ /// Assumes that `symbols` is sorted in order of ascending `addr`.
+ fn find(symbols: []const Symbol, address: usize) ?*const Symbol {
+ if (symbols.len == 0) return null; // no potential match
+ if (address < symbols[0].addr) return null; // address is before the lowest-address symbol
+ var left: usize = 0;
+ var len: usize = symbols.len;
+ while (len > 1) {
+ const mid = left + len / 2;
+ if (address < symbols[mid].addr) {
+ len /= 2;
+ } else {
+ left = mid;
+ len -= len / 2;
+ }
+ }
+ return &symbols[left];
+ }
+
+ test find {
+ const symbols: []const Symbol = &.{
+ .{ .addr = 100, .strx = undefined, .ofile = undefined },
+ .{ .addr = 200, .strx = undefined, .ofile = undefined },
+ .{ .addr = 300, .strx = undefined, .ofile = undefined },
+ };
+
+ try testing.expectEqual(null, find(symbols, 0));
+ try testing.expectEqual(null, find(symbols, 99));
+ try testing.expectEqual(&symbols[0], find(symbols, 100).?);
+ try testing.expectEqual(&symbols[0], find(symbols, 150).?);
+ try testing.expectEqual(&symbols[0], find(symbols, 199).?);
+
+ try testing.expectEqual(&symbols[1], find(symbols, 200).?);
+ try testing.expectEqual(&symbols[1], find(symbols, 250).?);
+ try testing.expectEqual(&symbols[1], find(symbols, 299).?);
+
+ try testing.expectEqual(&symbols[2], find(symbols, 300).?);
+ try testing.expectEqual(&symbols[2], find(symbols, 301).?);
+ try testing.expectEqual(&symbols[2], find(symbols, 5000).?);
+ }
+};
+test {
+ _ = Symbol;
+}
+
+fn loadOFile(gpa: Allocator, o_file_path: []const u8) !OFile {
+ const mapped_mem = try mapDebugInfoFile(o_file_path);
+ errdefer posix.munmap(mapped_mem);
+
+ var r: Io.Reader = .fixed(mapped_mem);
+ const hdr = r.takeStruct(macho.mach_header_64, .little) catch |err| switch (err) {
+ error.ReadFailed => unreachable,
+ error.EndOfStream => return error.InvalidMachO,
+ };
+ if (hdr.magic != std.macho.MH_MAGIC_64) return error.InvalidMachO;
+
+ const seg_cmd: macho.LoadCommandIterator.LoadCommand, const symtab_cmd: macho.symtab_command = cmds: {
+ var seg_cmd: ?macho.LoadCommandIterator.LoadCommand = null;
+ var symtab_cmd: ?macho.symtab_command = null;
+ var it: macho.LoadCommandIterator = try .init(&hdr, mapped_mem[@sizeOf(macho.mach_header_64)..]);
+ while (try it.next()) |lc| switch (lc.hdr.cmd) {
+ .SEGMENT_64 => seg_cmd = lc,
+ .SYMTAB => symtab_cmd = lc.cast(macho.symtab_command) orelse return error.InvalidMachO,
+ else => {},
+ };
+ break :cmds .{
+ seg_cmd orelse return error.MissingDebugInfo,
+ symtab_cmd orelse return error.MissingDebugInfo,
+ };
+ };
+
+ if (mapped_mem.len < symtab_cmd.stroff + symtab_cmd.strsize) return error.InvalidMachO;
+ if (mapped_mem[symtab_cmd.stroff + symtab_cmd.strsize - 1] != 0) return error.InvalidMachO;
+ const strtab = mapped_mem[symtab_cmd.stroff..][0 .. symtab_cmd.strsize - 1];
+
+ const n_sym_bytes = symtab_cmd.nsyms * @sizeOf(macho.nlist_64);
+ if (mapped_mem.len < symtab_cmd.symoff + n_sym_bytes) return error.InvalidMachO;
+ const symtab_raw: []align(1) const macho.nlist_64 = @ptrCast(mapped_mem[symtab_cmd.symoff..][0..n_sym_bytes]);
+
+ // TODO handle tentative (common) symbols
+ var symbols_by_name: std.ArrayHashMapUnmanaged(u32, void, void, true) = .empty;
+ defer symbols_by_name.deinit(gpa);
+ try symbols_by_name.ensureUnusedCapacity(gpa, @intCast(symtab_raw.len));
+ for (symtab_raw, 0..) |sym_raw, sym_index| {
+ var sym = sym_raw;
+ if (builtin.cpu.arch.endian() != .little) std.mem.byteSwapAllFields(macho.nlist_64, &sym);
+ if (sym.n_strx == 0) continue;
+ switch (sym.n_type.bits.type) {
+ .undf => continue, // includes tentative symbols
+ .abs => continue,
+ else => {},
+ }
+ const sym_name = mem.sliceTo(strtab[sym.n_strx..], 0);
+ const gop = symbols_by_name.getOrPutAssumeCapacityAdapted(
+ @as([]const u8, sym_name),
+ @as(OFile.SymbolAdapter, .{ .strtab = strtab, .symtab_raw = symtab_raw }),
+ );
+ if (gop.found_existing) return error.InvalidMachO;
+ gop.key_ptr.* = @intCast(sym_index);
+ }
+
+ var sections: Dwarf.SectionArray = @splat(null);
+ for (seg_cmd.getSections()) |sect_raw| {
+ var sect = sect_raw;
+ if (builtin.cpu.arch.endian() != .little) std.mem.byteSwapAllFields(macho.section_64, §);
+
+ if (!std.mem.eql(u8, "__DWARF", sect.segName())) continue;
+
+ const section_index: usize = inline for (@typeInfo(Dwarf.Section.Id).@"enum".fields, 0..) |section, i| {
+ if (mem.eql(u8, "__" ++ section.name, sect.sectName())) break i;
+ } else continue;
+
+ if (mapped_mem.len < sect.offset + sect.size) return error.InvalidMachO;
+ const section_bytes = mapped_mem[sect.offset..][0..sect.size];
+ sections[section_index] = .{
+ .data = section_bytes,
+ .owned = false,
+ };
+ }
+
+ if (sections[@intFromEnum(Dwarf.Section.Id.debug_info)] == null or
+ sections[@intFromEnum(Dwarf.Section.Id.debug_abbrev)] == null or
+ sections[@intFromEnum(Dwarf.Section.Id.debug_str)] == null or
+ sections[@intFromEnum(Dwarf.Section.Id.debug_line)] == null)
+ {
+ return error.MissingDebugInfo;
+ }
+
+ var dwarf: Dwarf = .{ .sections = sections };
+ errdefer dwarf.deinit(gpa);
+ dwarf.open(gpa, .little) catch |err| switch (err) {
+ error.InvalidDebugInfo,
+ error.EndOfStream,
+ error.Overflow,
+ error.StreamTooLong,
+ => return error.InvalidDwarf,
+
+ error.MissingDebugInfo,
+ error.ReadFailed,
+ error.OutOfMemory,
+ => |e| return e,
+ };
+
+ return .{
+ .mapped_memory = mapped_mem,
+ .dwarf = dwarf,
+ .strtab = strtab,
+ .symtab_raw = symtab_raw,
+ .symbols_by_name = symbols_by_name.move(),
+ };
+}
+
+/// Uses `mmap` to map the file at `path` into memory.
+fn mapDebugInfoFile(path: []const u8) ![]align(std.heap.page_size_min) const u8 {
+ const file = std.fs.cwd().openFile(path, .{}) catch |err| switch (err) {
+ error.FileNotFound => return error.MissingDebugInfo,
+ else => return error.ReadFailed,
+ };
+ defer file.close();
+
+ const file_len = std.math.cast(
+ usize,
+ file.getEndPos() catch return error.ReadFailed,
+ ) orelse return error.ReadFailed;
+
+ return posix.mmap(
+ null,
+ file_len,
+ posix.PROT.READ,
+ .{ .TYPE = .SHARED },
+ file.handle,
+ 0,
+ ) catch return error.ReadFailed;
+}
+
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const Dwarf = std.debug.Dwarf;
+const Io = std.Io;
+const assert = std.debug.assert;
+const posix = std.posix;
+const macho = std.macho;
+const mem = std.mem;
+const testing = std.testing;
+
+const builtin = @import("builtin");
+
+const MachOFile = @This();
lib/std/debug.zig
@@ -21,6 +21,7 @@ const root = @import("root");
pub const Dwarf = @import("debug/Dwarf.zig");
pub const Pdb = @import("debug/Pdb.zig");
pub const ElfFile = @import("debug/ElfFile.zig");
+pub const MachOFile = @import("debug/MachOFile.zig");
pub const Info = @import("debug/Info.zig");
pub const Coverage = @import("debug/Coverage.zig");
pub const cpu_context = @import("debug/cpu_context.zig");
lib/std/macho.zig
@@ -1902,74 +1902,76 @@ pub const data_in_code_entry = extern struct {
};
pub const LoadCommandIterator = struct {
+ next_index: usize,
ncmds: usize,
- buffer: []const u8,
- index: usize = 0,
+ r: std.Io.Reader,
pub const LoadCommand = struct {
hdr: load_command,
data: []const u8,
- pub fn cmd(lc: LoadCommand) LC {
- return lc.hdr.cmd;
- }
-
- pub fn cmdsize(lc: LoadCommand) u32 {
- return lc.hdr.cmdsize;
- }
-
pub fn cast(lc: LoadCommand, comptime Cmd: type) ?Cmd {
if (lc.data.len < @sizeOf(Cmd)) return null;
- return @as(*align(1) const Cmd, @ptrCast(lc.data.ptr)).*;
+ const ptr: *align(1) const Cmd = @ptrCast(lc.data.ptr);
+ var cmd = ptr.*;
+ if (builtin.cpu.arch.endian() != .little) std.mem.byteSwapAllFields(Cmd, &cmd);
+ return cmd;
}
/// Asserts LoadCommand is of type segment_command_64.
+ /// If the native endian is not `.little`, the `section_64` values must be byte-swapped by the caller.
pub fn getSections(lc: LoadCommand) []align(1) const section_64 {
const segment_lc = lc.cast(segment_command_64).?;
- if (segment_lc.nsects == 0) return &[0]section_64{};
- const data = lc.data[@sizeOf(segment_command_64)..];
- const sections = @as([*]align(1) const section_64, @ptrCast(data.ptr))[0..segment_lc.nsects];
- return sections;
+ const sects_ptr: [*]align(1) const section_64 = @ptrCast(lc.data[@sizeOf(segment_command_64)..]);
+ return sects_ptr[0..segment_lc.nsects];
}
/// Asserts LoadCommand is of type dylib_command.
pub fn getDylibPathName(lc: LoadCommand) []const u8 {
const dylib_lc = lc.cast(dylib_command).?;
- const data = lc.data[dylib_lc.dylib.name..];
- return mem.sliceTo(data, 0);
+ return mem.sliceTo(lc.data[dylib_lc.dylib.name..], 0);
}
/// Asserts LoadCommand is of type rpath_command.
pub fn getRpathPathName(lc: LoadCommand) []const u8 {
const rpath_lc = lc.cast(rpath_command).?;
- const data = lc.data[rpath_lc.path..];
- return mem.sliceTo(data, 0);
+ return mem.sliceTo(lc.data[rpath_lc.path..], 0);
}
/// Asserts LoadCommand is of type build_version_command.
+ /// If the native endian is not `.little`, the `build_tool_version` values must be byte-swapped by the caller.
pub fn getBuildVersionTools(lc: LoadCommand) []align(1) const build_tool_version {
const build_lc = lc.cast(build_version_command).?;
- const ntools = build_lc.ntools;
- if (ntools == 0) return &[0]build_tool_version{};
- const data = lc.data[@sizeOf(build_version_command)..];
- const tools = @as([*]align(1) const build_tool_version, @ptrCast(data.ptr))[0..ntools];
- return tools;
+ const tools_ptr: [*]align(1) const build_tool_version = @ptrCast(lc.data[@sizeOf(build_version_command)..]);
+ return tools_ptr[0..build_lc.ntools];
}
};
- pub fn next(it: *LoadCommandIterator) ?LoadCommand {
- if (it.index >= it.ncmds) return null;
+ pub fn next(it: *LoadCommandIterator) error{InvalidMachO}!?LoadCommand {
+ if (it.next_index >= it.ncmds) return null;
- const hdr = @as(*align(1) const load_command, @ptrCast(it.buffer.ptr)).*;
- const cmd = LoadCommand{
- .hdr = hdr,
- .data = it.buffer[0..hdr.cmdsize],
+ const hdr = it.r.peekStruct(load_command, .little) catch |err| switch (err) {
+ error.ReadFailed => unreachable,
+ error.EndOfStream => return error.InvalidMachO,
+ };
+ const data = it.r.take(hdr.cmdsize) catch |err| switch (err) {
+ error.ReadFailed => unreachable,
+ error.EndOfStream => return error.InvalidMachO,
};
- it.buffer = it.buffer[hdr.cmdsize..];
- it.index += 1;
+ it.next_index += 1;
+ return .{ .hdr = hdr, .data = data };
+ }
- return cmd;
+ pub fn init(hdr: *const mach_header_64, cmds_buf_overlong: []const u8) error{InvalidMachO}!LoadCommandIterator {
+ if (cmds_buf_overlong.len < hdr.sizeofcmds) return error.InvalidMachO;
+ if (hdr.ncmds > 0 and hdr.sizeofcmds < @sizeOf(load_command)) return error.InvalidMachO;
+ const cmds_buf = cmds_buf_overlong[0..hdr.sizeofcmds];
+ return .{
+ .next_index = 0,
+ .ncmds = hdr.ncmds,
+ .r = .fixed(cmds_buf),
+ };
}
};
src/link/MachO/Dylib.zig
@@ -90,11 +90,8 @@ fn parseBinary(self: *Dylib, macho_file: *MachO) !void {
if (amt != lc_buffer.len) return error.InputOutput;
}
- var it = LoadCommandIterator{
- .ncmds = header.ncmds,
- .buffer = lc_buffer,
- };
- while (it.next()) |cmd| switch (cmd.cmd()) {
+ var it = LoadCommandIterator.init(&header, lc_buffer) catch |err| std.debug.panic("bad dylib: {t}", .{err});
+ while (it.next() catch |err| std.debug.panic("bad dylib: {t}", .{err})) |cmd| switch (cmd.hdr.cmd) {
.ID_DYLIB => {
self.id = try Id.fromLoadCommand(gpa, cmd.cast(macho.dylib_command).?, cmd.getDylibPathName());
},
src/link/MachO/Object.zig
@@ -109,11 +109,8 @@ pub fn parse(self: *Object, macho_file: *MachO) !void {
if (amt != self.header.?.sizeofcmds) return error.InputOutput;
}
- var it = LoadCommandIterator{
- .ncmds = self.header.?.ncmds,
- .buffer = lc_buffer,
- };
- while (it.next()) |lc| switch (lc.cmd()) {
+ var it = LoadCommandIterator.init(&self.header.?, lc_buffer) catch |err| std.debug.panic("bad object: {t}", .{err});
+ while (it.next() catch |err| std.debug.panic("bad object: {t}", .{err})) |lc| switch (lc.hdr.cmd) {
.SEGMENT_64 => {
const sections = lc.getSections();
try self.sections.ensureUnusedCapacity(gpa, sections.len);
@@ -1644,11 +1641,8 @@ pub fn parseAr(self: *Object, macho_file: *MachO) !void {
if (amt != self.header.?.sizeofcmds) return error.InputOutput;
}
- var it = LoadCommandIterator{
- .ncmds = self.header.?.ncmds,
- .buffer = lc_buffer,
- };
- while (it.next()) |lc| switch (lc.cmd()) {
+ var it = LoadCommandIterator.init(&self.header.?, lc_buffer) catch |err| std.debug.panic("bad object: {t}", .{err});
+ while (it.next() catch |err| std.debug.panic("bad object: {t}", .{err})) |lc| switch (lc.hdr.cmd) {
.SYMTAB => {
const cmd = lc.cast(macho.symtab_command).?;
try self.strtab.resize(gpa, cmd.strsize);
src/link/MachO.zig
@@ -4167,7 +4167,7 @@ pub const Platform = struct {
/// Using Apple's ld64 as our blueprint, `min_version` as well as `sdk_version` are set to
/// the extracted minimum platform version.
pub fn fromLoadCommand(lc: macho.LoadCommandIterator.LoadCommand) Platform {
- switch (lc.cmd()) {
+ switch (lc.hdr.cmd) {
.BUILD_VERSION => {
const cmd = lc.cast(macho.build_version_command).?;
return .{
@@ -4200,7 +4200,7 @@ pub const Platform = struct {
// We can't distinguish Mac Catalyst here, but this is legacy stuff anyway.
const cmd = lc.cast(macho.version_min_command).?;
return .{
- .os_tag = switch (lc.cmd()) {
+ .os_tag = switch (lc.hdr.cmd) {
.VERSION_MIN_IPHONEOS => .ios,
.VERSION_MIN_MACOSX => .macos,
.VERSION_MIN_TVOS => .tvos,