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zld: start bringing x64 up to speed

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This commit is contained in:
Jakub Konka 2021-03-03 01:52:21 +01:00
parent 066c1386a3
commit a1b0ec5277
4 changed files with 333 additions and 151 deletions
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14
lib/std/macho.zig
View File

@ -1615,3 +1615,17 @@ pub const GenericBlob = extern struct {
/// Total length of blob
length: u32,
};
/// The LC_DATA_IN_CODE load commands uses a linkedit_data_command
/// to point to an array of data_in_code_entry entries. Each entry
/// describes a range of data in a code section.
pub const data_in_code_entry = extern struct {
/// From mach_header to start of data range.
offset: u32,
/// Number of bytes in data range.
length: u16,
/// A DICE_KIND value.
kind: u16,
};

2
src/link/MachO/Archive.zig
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@ -210,6 +210,8 @@ fn readObject(self: *Archive, arch: std.Target.Cpu.Arch, ar_name: []const u8, re
try object.readSymtab();
try object.readStrtab();
if (object.data_in_code_cmd_index != null) try object.readDataInCode();
log.debug("\n\n", .{});
log.debug("{s} defines symbols", .{object.name});
for (object.symtab.items) |sym| {

30
src/link/MachO/Object.zig
View File

@ -3,6 +3,7 @@ const Object = @This();
const std = @import("std");
const assert = std.debug.assert;
const fs = std.fs;
const io = std.io;
const log = std.log.scoped(.object);
const macho = std.macho;
const mem = std.mem;
@ -24,6 +25,7 @@ segment_cmd_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,
// __DWARF segment sections
@ -36,6 +38,8 @@ dwarf_debug_ranges_index: ?u16 = null,
symtab: std.ArrayListUnmanaged(macho.nlist_64) = .{},
strtab: std.ArrayListUnmanaged(u8) = .{},
data_in_code_entries: std.ArrayListUnmanaged(macho.data_in_code_entry) = .{},
pub fn deinit(self: *Object) void {
for (self.load_commands.items) |*lc| {
lc.deinit(self.allocator);
@ -43,6 +47,7 @@ pub fn deinit(self: *Object) void {
self.load_commands.deinit(self.allocator);
self.symtab.deinit(self.allocator);
self.strtab.deinit(self.allocator);
self.data_in_code_entries.deinit(self.allocator);
self.allocator.free(self.name);
self.file.close();
}
@ -83,6 +88,8 @@ pub fn initFromFile(allocator: *Allocator, arch: std.Target.Cpu.Arch, name: []co
try self.readSymtab();
try self.readStrtab();
if (self.data_in_code_cmd_index != null) try self.readDataInCode();
log.debug("\n\n", .{});
log.debug("{s} defines symbols", .{self.name});
for (self.symtab.items) |sym| {
@ -148,6 +155,9 @@ pub fn readLoadCommands(self: *Object, reader: anytype, offset: ReadOffset) !voi
macho.LC_BUILD_VERSION => {
self.build_version_cmd_index = i;
},
macho.LC_DATA_IN_CODE => {
self.data_in_code_cmd_index = i;
},
else => {
log.debug("Unknown load command detected: 0x{x}.", .{cmd.cmd()});
},
@ -189,3 +199,23 @@ pub fn readSection(self: Object, allocator: *Allocator, index: u16) ![]u8 {
_ = try self.file.preadAll(buffer, sect.offset);
return buffer;
}
pub fn readDataInCode(self: *Object) !void {
const index = self.data_in_code_cmd_index orelse return;
const data_in_code = self.load_commands.items[index].LinkeditData;
var buffer = try self.allocator.alloc(u8, data_in_code.datasize);
defer self.allocator.free(buffer);
_ = try self.file.preadAll(buffer, data_in_code.dataoff);
var stream = io.fixedBufferStream(buffer);
var reader = stream.reader();
while (true) {
const dice = reader.readStruct(macho.data_in_code_entry) catch |err| switch (err) {
error.EndOfStream => break,
else => |e| return e,
};
try self.data_in_code_entries.append(self.allocator, dice);
}
}

438
src/link/MachO/Zld.zig
View File

@ -332,7 +332,7 @@ fn mapAndUpdateSections(
const target_seg = &self.load_commands.items[target_seg_id].Segment;
const target_sect = &target_seg.sections.items[target_sect_id];
const alignment = try math.powi(u32, 2, source_sect.@"align");
const alignment = try math.powi(u32, 2, target_sect.@"align");
const offset = mem.alignForwardGeneric(u64, target_sect.size, alignment);
const size = mem.alignForwardGeneric(u64, source_sect.size, alignment);
const key = MappingKey{
@ -345,7 +345,7 @@ fn mapAndUpdateSections(
.target_sect_id = target_sect_id,
.offset = @intCast(u32, offset),
});
log.debug("{s}: {s},{s} mapped to {s},{s} from 0x{x} to 0x{x}", .{
log.warn("{s}: {s},{s} mapped to {s},{s} from 0x{x} to 0x{x}", .{
object.name,
parseName(&source_sect.segname),
parseName(&source_sect.sectname),
@ -355,7 +355,6 @@ fn mapAndUpdateSections(
offset + size,
});
target_sect.@"align" = math.max(target_sect.@"align", source_sect.@"align");
target_sect.size = offset + size;
}
@ -514,120 +513,117 @@ fn updateMetadata(self: *Zld, object_id: u16) !void {
});
},
else => {
log.debug("unhandled section type 0x{x} for '{s}/{s}'", .{ flags, segname, sectname });
log.warn("unhandled section type 0x{x} for '{s}/{s}'", .{ flags, segname, sectname });
},
}
}
// Find ideal section alignment.
for (object_seg.sections.items) |source_sect, id| {
if (self.getMatchingSection(source_sect)) |res| {
const target_seg = &self.load_commands.items[res.seg].Segment;
const target_sect = &target_seg.sections.items[res.sect];
target_sect.@"align" = math.max(target_sect.@"align", source_sect.@"align");
}
}
// Update section mappings
// __TEXT,__text has to be always defined!
try self.mapAndUpdateSections(
object_id,
object.text_section_index.?,
self.text_segment_cmd_index.?,
self.text_section_index.?,
);
for (object_seg.sections.items) |source_sect, id| {
const source_sect_id = @intCast(u16, id);
if (id == object.text_section_index.?) continue;
if (self.getMatchingSection(source_sect)) |res| {
try self.mapAndUpdateSections(object_id, source_sect_id, res.seg, res.sect);
continue;
}
const segname = parseName(&source_sect.segname);
const sectname = parseName(&source_sect.sectname);
const flags = source_sect.flags;
log.warn("section '{s}/{s}' will be unmapped", .{ segname, sectname });
try self.unhandled_sections.putNoClobber(self.allocator, .{
.object_id = object_id,
.source_sect_id = source_sect_id,
}, 0);
}
}
switch (flags) {
const MatchingSection = struct {
seg: u16,
sect: u16,
};
fn getMatchingSection(self: *Zld, section: macho.section_64) ?MatchingSection {
const segname = parseName(&section.segname);
const sectname = parseName(&section.sectname);
const res: ?MatchingSection = blk: {
switch (section.flags) {
macho.S_4BYTE_LITERALS, macho.S_8BYTE_LITERALS, macho.S_16BYTE_LITERALS => {
try self.mapAndUpdateSections(
object_id,
source_sect_id,
self.text_segment_cmd_index.?,
self.text_const_section_index.?,
);
break :blk .{
.seg = self.text_segment_cmd_index.?,
.sect = self.text_const_section_index.?,
};
},
macho.S_CSTRING_LITERALS => {
try self.mapAndUpdateSections(
object_id,
source_sect_id,
self.text_segment_cmd_index.?,
self.cstring_section_index.?,
);
break :blk .{
.seg = self.text_segment_cmd_index.?,
.sect = self.cstring_section_index.?,
};
},
macho.S_ZEROFILL => {
try self.mapAndUpdateSections(
object_id,
source_sect_id,
self.data_segment_cmd_index.?,
self.bss_section_index.?,
);
break :blk .{
.seg = self.data_segment_cmd_index.?,
.sect = self.bss_section_index.?,
};
},
macho.S_THREAD_LOCAL_VARIABLES => {
try self.mapAndUpdateSections(
object_id,
source_sect_id,
self.data_segment_cmd_index.?,
self.tlv_section_index.?,
);
break :blk .{
.seg = self.data_segment_cmd_index.?,
.sect = self.tlv_section_index.?,
};
},
macho.S_THREAD_LOCAL_REGULAR => {
try self.mapAndUpdateSections(
object_id,
source_sect_id,
self.data_segment_cmd_index.?,
self.tlv_data_section_index.?,
);
break :blk .{
.seg = self.data_segment_cmd_index.?,
.sect = self.tlv_data_section_index.?,
};
},
macho.S_THREAD_LOCAL_ZEROFILL => {
try self.mapAndUpdateSections(
object_id,
source_sect_id,
self.data_segment_cmd_index.?,
self.tlv_bss_section_index.?,
);
break :blk .{
.seg = self.data_segment_cmd_index.?,
.sect = self.tlv_bss_section_index.?,
};
},
macho.S_REGULAR | macho.S_ATTR_PURE_INSTRUCTIONS | macho.S_ATTR_SOME_INSTRUCTIONS => {
break :blk .{
.seg = self.text_segment_cmd_index.?,
.sect = self.text_section_index.?,
};
},
macho.S_REGULAR => {
if (mem.eql(u8, segname, "__TEXT")) {
try self.mapAndUpdateSections(
object_id,
source_sect_id,
self.text_segment_cmd_index.?,
self.text_const_section_index.?,
);
continue;
break :blk .{
.seg = self.text_segment_cmd_index.?,
.sect = self.text_const_section_index.?,
};
} else if (mem.eql(u8, segname, "__DATA")) {
if (mem.eql(u8, sectname, "__data")) {
try self.mapAndUpdateSections(
object_id,
source_sect_id,
self.data_segment_cmd_index.?,
self.data_section_index.?,
);
continue;
break :blk .{
.seg = self.data_segment_cmd_index.?,
.sect = self.data_section_index.?,
};
} else if (mem.eql(u8, sectname, "__const")) {
try self.mapAndUpdateSections(
object_id,
source_sect_id,
self.data_segment_cmd_index.?,
self.data_const_section_index.?,
);
continue;
break :blk .{
.seg = self.data_segment_cmd_index.?,
.sect = self.data_const_section_index.?,
};
}
}
log.debug("section '{s}/{s}' will be unmapped", .{ segname, sectname });
try self.unhandled_sections.putNoClobber(self.allocator, .{
.object_id = object_id,
.source_sect_id = source_sect_id,
}, 0);
break :blk null;
},
else => {
log.debug("section '{s}/{s}' will be unmapped", .{ segname, sectname });
try self.unhandled_sections.putNoClobber(self.allocator, .{
.object_id = object_id,
.source_sect_id = source_sect_id,
}, 0);
break :blk null;
},
}
}
};
return res;
}
fn sortSections(self: *Zld) !void {
@ -784,7 +780,7 @@ fn resolveImports(self: *Zld) !void {
mem.eql(u8, sym_name, "___stack_chk_guard") or
mem.eql(u8, sym_name, "_environ"))
{
log.debug("writing nonlazy symbol '{s}'", .{sym_name});
log.warn("writing nonlazy symbol '{s}'", .{sym_name});
const index = @intCast(u32, self.nonlazy_imports.items().len);
try self.nonlazy_imports.putNoClobber(self.allocator, key, .{
.symbol = new_sym,
@ -792,7 +788,7 @@ fn resolveImports(self: *Zld) !void {
.index = index,
});
} else if (mem.eql(u8, sym_name, "__tlv_bootstrap")) {
log.debug("writing threadlocal symbol '{s}'", .{sym_name});
log.warn("writing threadlocal symbol '{s}'", .{sym_name});
const index = @intCast(u32, self.threadlocal_imports.items().len);
try self.threadlocal_imports.putNoClobber(self.allocator, key, .{
.symbol = new_sym,
@ -800,7 +796,7 @@ fn resolveImports(self: *Zld) !void {
.index = index,
});
} else {
log.debug("writing lazy symbol '{s}'", .{sym_name});
log.warn("writing lazy symbol '{s}'", .{sym_name});
const index = @intCast(u32, self.lazy_imports.items().len);
try self.lazy_imports.putNoClobber(self.allocator, key, .{
.symbol = new_sym,
@ -812,7 +808,7 @@ fn resolveImports(self: *Zld) !void {
const n_strx = try self.makeString("dyld_stub_binder");
const name = try self.allocator.dupe(u8, "dyld_stub_binder");
log.debug("writing nonlazy symbol 'dyld_stub_binder'", .{});
log.warn("writing nonlazy symbol 'dyld_stub_binder'", .{});
const index = @intCast(u32, self.nonlazy_imports.items().len);
try self.nonlazy_imports.putNoClobber(self.allocator, name, .{
.symbol = .{
@ -1016,7 +1012,7 @@ fn writeStubHelperCommon(self: *Zld) !void {
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;
log.debug("2: disp=0x{x}, literal=0x{x}", .{ displacement, literal });
log.warn("2: disp=0x{x}, literal=0x{x}", .{ displacement, literal });
// Pad with nop to please division.
// nop
mem.writeIntLittle(u32, code[12..16], Arm64.nop().toU32());
@ -1069,7 +1065,7 @@ fn writeLazySymbolPointer(self: *Zld, index: u32) !void {
var buf: [@sizeOf(u64)]u8 = undefined;
mem.writeIntLittle(u64, &buf, end);
const off = la_symbol_ptr.offset + index * @sizeOf(u64);
log.debug("writing lazy symbol pointer entry 0x{x} at 0x{x}", .{ end, off });
log.warn("writing lazy symbol pointer entry 0x{x} at 0x{x}", .{ end, off });
try self.file.?.pwriteAll(&buf, off);
}
@ -1082,7 +1078,7 @@ fn writeStub(self: *Zld, index: u32) !void {
const stub_off = stubs.offset + index * stubs.reserved2;
const stub_addr = stubs.addr + index * stubs.reserved2;
const la_ptr_addr = la_symbol_ptr.addr + index * @sizeOf(u64);
log.debug("writing stub at 0x{x}", .{stub_off});
log.warn("writing stub at 0x{x}", .{stub_off});
var code = try self.allocator.alloc(u8, stubs.reserved2);
defer self.allocator.free(code);
switch (self.arch.?) {
@ -1229,7 +1225,7 @@ fn resolveSymbols(self: *Zld) !void {
const target_addr = target_sect.addr + target_mapping.offset;
const n_value = sym.n_value - source_sect.addr + target_addr;
log.debug("resolving '{s}':{} as {s} symbol at 0x{x}", .{ sym_name, sym, tt, n_value });
log.warn("resolving '{s}':{} as {s} symbol at 0x{x}", .{ sym_name, sym, tt, n_value });
// TODO this assumes only two symbol-filled segments. Also, there might be a more
// generic way of doing this.
@ -1259,8 +1255,8 @@ fn resolveSymbols(self: *Zld) !void {
fn doRelocs(self: *Zld) !void {
for (self.objects.items) |object, object_id| {
log.debug("\n\n", .{});
log.debug("relocating object {s}", .{object.name});
log.warn("\n\n", .{});
log.warn("relocating object {s}", .{object.name});
const seg = object.load_commands.items[object.segment_cmd_index.?].Segment;
@ -1283,7 +1279,7 @@ fn doRelocs(self: *Zld) !void {
.object_id = @intCast(u16, object_id),
.source_sect_id = @intCast(u16, source_sect_id),
}) orelse {
log.debug("no mapping for {s},{s}; skipping", .{ segname, sectname });
log.warn("no mapping for {s},{s}; skipping", .{ segname, sectname });
continue;
};
const target_seg = self.load_commands.items[target_mapping.target_seg_id].Segment;
@ -1301,34 +1297,34 @@ fn doRelocs(self: *Zld) !void {
switch (self.arch.?) {
.aarch64 => {
const rel_type = @intToEnum(macho.reloc_type_arm64, rel.r_type);
log.debug("{s}", .{rel_type});
log.debug(" | source address 0x{x}", .{this_addr});
log.debug(" | offset 0x{x}", .{off});
log.warn("{s}", .{rel_type});
log.warn(" | source address 0x{x}", .{this_addr});
log.warn(" | offset 0x{x}", .{off});
if (rel_type == .ARM64_RELOC_ADDEND) {
addend = rel.r_symbolnum;
log.debug(" | calculated addend = 0x{x}", .{addend});
log.warn(" | calculated addend = 0x{x}", .{addend});
// TODO followed by either PAGE21 or PAGEOFF12 only.
continue;
}
},
.x86_64 => {
const rel_type = @intToEnum(macho.reloc_type_x86_64, rel.r_type);
log.debug("{s}", .{rel_type});
log.debug(" | source address 0x{x}", .{this_addr});
log.debug(" | offset 0x{x}", .{off});
log.warn("{s}", .{rel_type});
log.warn(" | source address 0x{x}", .{this_addr});
log.warn(" | offset 0x{x}", .{off});
},
else => {},
}
const target_addr = try self.relocTargetAddr(@intCast(u16, object_id), rel);
log.debug(" | target address 0x{x}", .{target_addr});
log.warn(" | target address 0x{x}", .{target_addr});
if (rel.r_extern == 1) {
const target_symname = object.getString(object.symtab.items[rel.r_symbolnum].n_strx);
log.debug(" | target symbol '{s}'", .{target_symname});
log.warn(" | target symbol '{s}'", .{target_symname});
} else {
const target_sectname = seg.sections.items[rel.r_symbolnum - 1].sectname;
log.debug(" | target section '{s}'", .{parseName(&target_sectname)});
log.warn(" | target section '{s}'", .{parseName(&target_sectname)});
}
switch (self.arch.?) {
@ -1361,13 +1357,12 @@ fn doRelocs(self: *Zld) !void {
=> {
assert(rel.r_length == 2);
const inst = code[off..][0..4];
const offset: i32 = blk: {
const offset = @intCast(i64, mem.readIntLittle(i32, inst));
log.warn(" | calculated addend 0x{x}", .{offset});
const actual_target_addr = blk: {
if (rel.r_extern == 1) {
break :blk mem.readIntLittle(i32, inst);
break :blk @intCast(i64, target_addr) + offset;
} else {
// TODO it might be required here to parse the offset from the instruction placeholder,
// compare the displacement with the original displacement in the .o file, and adjust
// the displacement in the resultant binary file.
const correction: i4 = switch (rel_type) {
.X86_64_RELOC_SIGNED => 0,
.X86_64_RELOC_SIGNED_1 => 1,
@ -1375,11 +1370,28 @@ fn doRelocs(self: *Zld) !void {
.X86_64_RELOC_SIGNED_4 => 4,
else => unreachable,
};
break :blk correction;
log.warn(" | calculated correction 0x{x}", .{correction});
// The value encoded in the instruction is a displacement - 4 - correction.
// To obtain the adjusted target address in the final binary, we need
// calculate the original target address within the object file, establish
// what the offset from the original target section was, and apply this
// offset to the resultant target section with this relocated binary.
const orig_sect_id = @intCast(u16, rel.r_symbolnum - 1);
const target_map = self.mappings.get(.{
.object_id = @intCast(u16, object_id),
.source_sect_id = orig_sect_id,
}) orelse unreachable;
const orig_seg = object.load_commands.items[object.segment_cmd_index.?].Segment;
const orig_sect = orig_seg.sections.items[orig_sect_id];
const orig_offset = off + offset + 4 + correction - @intCast(i64, orig_sect.addr);
log.warn(" | original offset 0x{x}", .{orig_offset});
const adjusted = @intCast(i64, target_addr) + orig_offset;
log.warn(" | adjusted target address 0x{x}", .{adjusted});
break :blk adjusted - correction;
}
};
log.debug(" | calculated addend 0x{x}", .{offset});
const result = @intCast(i64, target_addr) - @intCast(i64, this_addr) - 4 + offset;
const result = actual_target_addr - @intCast(i64, this_addr) - 4;
const displacement = @bitCast(u32, @intCast(i32, result));
mem.writeIntLittle(u32, inst, displacement);
},
@ -1391,11 +1403,40 @@ fn doRelocs(self: *Zld) !void {
3 => {
const inst = code[off..][0..8];
const offset = mem.readIntLittle(i64, inst);
log.debug(" | calculated addend 0x{x}", .{offset});
const result = if (sub) |s|
@intCast(i64, target_addr) - s + offset
else
@intCast(i64, target_addr) + offset;
const result = outer: {
if (rel.r_extern == 1) {
log.warn(" | calculated addend 0x{x}", .{offset});
if (sub) |s| {
break :outer @intCast(i64, target_addr) - s + offset;
} else {
break :outer @intCast(i64, target_addr) + offset;
}
} else {
// The value encoded in the instruction is an absolute offset
// from the start of MachO header to the target address in the
// object file. To extract the address, we calculate the offset from
// the beginning of the source section to the address, and apply it to
// the target address value.
const orig_sect_id = @intCast(u16, rel.r_symbolnum - 1);
const target_map = self.mappings.get(.{
.object_id = @intCast(u16, object_id),
.source_sect_id = orig_sect_id,
}) orelse unreachable;
const orig_seg = object.load_commands.items[object.segment_cmd_index.?].Segment;
const orig_sect = orig_seg.sections.items[orig_sect_id];
const orig_offset = offset - @intCast(i64, orig_sect.addr);
const actual_target_addr = inner: {
if (sub) |s| {
break :inner @intCast(i64, target_addr) - s + orig_offset;
} else {
break :inner @intCast(i64, target_addr) + orig_offset;
}
};
log.warn(" | adjusted target address 0x{x}", .{actual_target_addr});
break :outer actual_target_addr;
}
};
mem.writeIntLittle(u64, inst, @bitCast(u64, result));
sub = null;
@ -1422,7 +1463,7 @@ fn doRelocs(self: *Zld) !void {
2 => {
const inst = code[off..][0..4];
const offset = mem.readIntLittle(i32, inst);
log.debug(" | calculated addend 0x{x}", .{offset});
log.warn(" | calculated addend 0x{x}", .{offset});
const result = if (sub) |s|
@intCast(i64, target_addr) - s + offset
else
@ -1459,7 +1500,7 @@ fn doRelocs(self: *Zld) !void {
const this_page = @intCast(i32, this_addr >> 12);
const target_page = @intCast(i32, ta >> 12);
const pages = @bitCast(u21, @intCast(i21, target_page - this_page));
log.debug(" | moving by {} pages", .{pages});
log.warn(" | moving by {} pages", .{pages});
var parsed = mem.bytesAsValue(meta.TagPayload(Arm64, Arm64.Address), inst);
parsed.immhi = @truncate(u19, pages >> 2);
parsed.immlo = @truncate(u2, pages);
@ -1470,14 +1511,14 @@ fn doRelocs(self: *Zld) !void {
=> {
const inst = code[off..][0..4];
if (Arm64.isArithmetic(inst)) {
log.debug(" | detected ADD opcode", .{});
log.warn(" | detected ADD opcode", .{});
// add
var parsed = mem.bytesAsValue(meta.TagPayload(Arm64, Arm64.Add), inst);
const ta = if (addend) |a| target_addr + a else target_addr;
const narrowed = @truncate(u12, ta);
parsed.offset = narrowed;
} else {
log.debug(" | detected LDR/STR opcode", .{});
log.warn(" | detected LDR/STR opcode", .{});
// ldr/str
var parsed = mem.bytesAsValue(meta.TagPayload(Arm64, Arm64.LoadRegister), inst);
const ta = if (addend) |a| target_addr + a else target_addr;
@ -1518,7 +1559,7 @@ fn doRelocs(self: *Zld) !void {
};
const ta = if (addend) |a| target_addr + a else target_addr;
const narrowed = @truncate(u12, ta);
log.debug(" | rewriting TLV access to ADD opcode", .{});
log.warn(" | rewriting TLV access to ADD opcode", .{});
// For TLV, we always generate an add instruction.
mem.writeIntLittle(u32, inst, Arm64.add(parsed.rt, parsed.rn, narrowed, parsed.size).toU32());
},
@ -1530,7 +1571,7 @@ fn doRelocs(self: *Zld) !void {
3 => {
const inst = code[off..][0..8];
const offset = mem.readIntLittle(i64, inst);
log.debug(" | calculated addend 0x{x}", .{offset});
log.warn(" | calculated addend 0x{x}", .{offset});
const result = if (sub) |s|
@intCast(i64, target_addr) - s + offset
else
@ -1561,7 +1602,7 @@ fn doRelocs(self: *Zld) !void {
2 => {
const inst = code[off..][0..4];
const offset = mem.readIntLittle(i32, inst);
log.debug(" | calculated addend 0x{x}", .{offset});
log.warn(" | calculated addend 0x{x}", .{offset});
const result = if (sub) |s|
@intCast(i64, target_addr) - s + offset
else
@ -1583,7 +1624,7 @@ fn doRelocs(self: *Zld) !void {
}
}
log.debug("writing contents of '{s},{s}' section from '{s}' from 0x{x} to 0x{x}", .{
log.warn("writing contents of '{s},{s}' section from '{s}' from 0x{x} to 0x{x}", .{
segname,
sectname,
object.name,
@ -1595,7 +1636,7 @@ fn doRelocs(self: *Zld) !void {
target_sect.flags == macho.S_THREAD_LOCAL_ZEROFILL or
target_sect.flags == macho.S_THREAD_LOCAL_VARIABLES)
{
log.debug("zeroing out '{s},{s}' from 0x{x} to 0x{x}", .{
log.warn("zeroing out '{s},{s}' from 0x{x} to 0x{x}", .{
parseName(&target_sect.segname),
parseName(&target_sect.sectname),
target_sect_off,
@ -1629,7 +1670,7 @@ fn relocTargetAddr(self: *Zld, object_id: u16, rel: macho.relocation_info) !u64
const target_seg = self.load_commands.items[target_mapping.target_seg_id].Segment;
const target_sect = target_seg.sections.items[target_mapping.target_sect_id];
const target_sect_addr = target_sect.addr + target_mapping.offset;
log.debug(" | symbol local to object", .{});
log.warn(" | symbol local to object", .{});
break :blk target_sect_addr + sym.n_value - source_sect.addr;
} else if (isImport(&sym)) {
// Relocate to either the artifact's local symbol, or an import from
@ -2059,6 +2100,18 @@ fn populateMetadata(self: *Zld) !void {
},
});
}
if (self.data_in_code_cmd_index == null and self.arch.? == .x86_64) {
self.data_in_code_cmd_index = @intCast(u16, self.load_commands.items.len);
try self.load_commands.append(self.allocator, .{
.LinkeditData = .{
.cmd = macho.LC_DATA_IN_CODE,
.cmdsize = @sizeOf(macho.linkedit_data_command),
.dataoff = 0,
.datasize = 0,
},
});
}
}
fn flush(self: *Zld) !void {
@ -2077,6 +2130,9 @@ fn flush(self: *Zld) !void {
try self.writeBindInfoTable();
try self.writeLazyBindInfoTable();
try self.writeExportInfo();
if (self.arch.? == .x86_64) {
try self.writeDataInCode();
}
{
const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment;
@ -2169,12 +2225,42 @@ fn writeRebaseInfoTable(self: *Zld) !void {
}
try pointers.ensureCapacity(pointers.items.len + self.local_rebases.items.len);
pointers.appendSliceAssumeCapacity(self.local_rebases.items);
const nlocals = self.local_rebases.items.len;
var i = nlocals;
while (i > 0) : (i -= 1) {
pointers.appendAssumeCapacity(self.local_rebases.items[i - 1]);
}
// const text_seg = self.load_commands.items[self.text_segment_cmd_index.?].Segment;
// const base_id = text_seg.sections.items.len;
// for (self.locals.items()) |entry| {
// for (entry.value.items) |symbol| {
// const local = symbol.inner;
// if (self.data_const_section_index) |index| {
// if (local.n_sect == base_id + index) {
// const offset = local.n_value - data_seg.inner.vmaddr;
// try pointers.append(.{
// .offset = offset,
// .segment_id = @intCast(u16, self.data_segment_cmd_index.?),
// });
// }
// }
// if (self.data_section_index) |index| {
// if (local.n_sect == base_id + index) {
// const offset = local.n_value - data_seg.inner.vmaddr;
// try pointers.append(.{
// .offset = offset,
// .segment_id = @intCast(u16, self.data_segment_cmd_index.?),
// });
// }
// }
// }
// }
std.sort.sort(Pointer, pointers.items, {}, pointerCmp);
// const nlocals = self.local_rebases.items.len;
// var i = nlocals;
// while (i > 0) : (i -= 1) {
// pointers.appendAssumeCapacity(self.local_rebases.items[i - 1]);
// }
const size = try rebaseInfoSize(pointers.items);
var buffer = try self.allocator.alloc(u8, @intCast(usize, size));
@ -2189,11 +2275,19 @@ fn writeRebaseInfoTable(self: *Zld) !void {
dyld_info.rebase_size = @intCast(u32, mem.alignForwardGeneric(u64, buffer.len, @sizeOf(u64)));
seg.inner.filesize += dyld_info.rebase_size;
log.debug("writing rebase info from 0x{x} to 0x{x}", .{ dyld_info.rebase_off, dyld_info.rebase_off + dyld_info.rebase_size });
log.warn("writing rebase info from 0x{x} to 0x{x}", .{ dyld_info.rebase_off, dyld_info.rebase_off + dyld_info.rebase_size });
try self.file.?.pwriteAll(buffer, dyld_info.rebase_off);
}
fn pointerCmp(context: void, a: Pointer, b: Pointer) bool {
if (a.segment_id < b.segment_id) return true;
if (a.segment_id == b.segment_id) {
return a.offset < b.offset;
}
return false;
}
fn writeBindInfoTable(self: *Zld) !void {
const data_seg = self.load_commands.items[self.data_segment_cmd_index.?].Segment;
@ -2242,7 +2336,7 @@ fn writeBindInfoTable(self: *Zld) !void {
dyld_info.bind_size = @intCast(u32, mem.alignForwardGeneric(u64, buffer.len, @alignOf(u64)));
seg.inner.filesize += dyld_info.bind_size;
log.debug("writing binding info from 0x{x} to 0x{x}", .{ dyld_info.bind_off, dyld_info.bind_off + dyld_info.bind_size });
log.warn("writing binding info from 0x{x} to 0x{x}", .{ dyld_info.bind_off, dyld_info.bind_off + dyld_info.bind_size });
try self.file.?.pwriteAll(buffer, dyld_info.bind_off);
}
@ -2281,7 +2375,7 @@ fn writeLazyBindInfoTable(self: *Zld) !void {
dyld_info.lazy_bind_size = @intCast(u32, mem.alignForwardGeneric(u64, buffer.len, @alignOf(u64)));
seg.inner.filesize += dyld_info.lazy_bind_size;
log.debug("writing lazy binding info from 0x{x} to 0x{x}", .{ dyld_info.lazy_bind_off, dyld_info.lazy_bind_off + dyld_info.lazy_bind_size });
log.warn("writing lazy binding info from 0x{x} to 0x{x}", .{ dyld_info.lazy_bind_off, dyld_info.lazy_bind_off + dyld_info.lazy_bind_size });
try self.file.?.pwriteAll(buffer, dyld_info.lazy_bind_off);
try self.populateLazyBindOffsetsInStubHelper(buffer);
@ -2383,7 +2477,7 @@ fn writeExportInfo(self: *Zld) !void {
dyld_info.export_size = @intCast(u32, mem.alignForwardGeneric(u64, buffer.len, @alignOf(u64)));
seg.inner.filesize += dyld_info.export_size;
log.debug("writing export info from 0x{x} to 0x{x}", .{ dyld_info.export_off, dyld_info.export_off + dyld_info.export_size });
log.warn("writing export info from 0x{x} to 0x{x}", .{ dyld_info.export_off, dyld_info.export_off + dyld_info.export_size });
try self.file.?.pwriteAll(buffer, dyld_info.export_off);
}
@ -2517,7 +2611,7 @@ fn writeDebugInfo(self: *Zld) !void {
const stabs_off = symtab.symoff;
const stabs_size = symtab.nsyms * @sizeOf(macho.nlist_64);
log.debug("writing symbol stabs from 0x{x} to 0x{x}", .{ stabs_off, stabs_size + stabs_off });
log.warn("writing symbol stabs from 0x{x} to 0x{x}", .{ stabs_off, stabs_size + stabs_off });
try self.file.?.pwriteAll(mem.sliceAsBytes(stabs.items), stabs_off);
linkedit.inner.filesize += stabs_size;
@ -2535,12 +2629,12 @@ fn writeSymbolTable(self: *Zld) !void {
defer locals.deinit();
for (self.locals.items()) |entries| {
log.debug("'{s}': {} entries", .{ entries.key, entries.value.items.len });
log.warn("'{s}': {} entries", .{ entries.key, entries.value.items.len });
// var symbol: ?macho.nlist_64 = null;
for (entries.value.items) |entry| {
log.debug(" | {}", .{entry.inner});
log.debug(" | {}", .{entry.tt});
log.debug(" | {s}", .{self.objects.items[entry.object_id].name});
log.warn(" | {}", .{entry.inner});
log.warn(" | {}", .{entry.tt});
log.warn(" | {s}", .{self.objects.items[entry.object_id].name});
// switch (entry.tt) {
// .Global => {
// symbol = entry.inner;
@ -2585,17 +2679,17 @@ fn writeSymbolTable(self: *Zld) !void {
const locals_off = symtab.symoff + symtab.nsyms * @sizeOf(macho.nlist_64);
const locals_size = nlocals * @sizeOf(macho.nlist_64);
log.debug("writing local symbols from 0x{x} to 0x{x}", .{ locals_off, locals_size + locals_off });
log.warn("writing local symbols from 0x{x} to 0x{x}", .{ locals_off, locals_size + locals_off });
try self.file.?.pwriteAll(mem.sliceAsBytes(locals.items), locals_off);
const exports_off = locals_off + locals_size;
const exports_size = nexports * @sizeOf(macho.nlist_64);
log.debug("writing exported symbols from 0x{x} to 0x{x}", .{ exports_off, exports_size + exports_off });
log.warn("writing exported symbols from 0x{x} to 0x{x}", .{ exports_off, exports_size + exports_off });
try self.file.?.pwriteAll(mem.sliceAsBytes(exports.items), exports_off);
const undefs_off = exports_off + exports_size;
const undefs_size = nundefs * @sizeOf(macho.nlist_64);
log.debug("writing undefined symbols from 0x{x} to 0x{x}", .{ undefs_off, undefs_size + undefs_off });
log.warn("writing undefined symbols from 0x{x} to 0x{x}", .{ undefs_off, undefs_size + undefs_off });
try self.file.?.pwriteAll(mem.sliceAsBytes(undefs.items), undefs_off);
symtab.nsyms += @intCast(u32, nlocals + nexports + nundefs);
@ -2626,7 +2720,7 @@ fn writeDynamicSymbolTable(self: *Zld) !void {
const needed_size = dysymtab.nindirectsyms * @sizeOf(u32);
seg.inner.filesize += needed_size;
log.debug("writing indirect symbol table from 0x{x} to 0x{x}", .{
log.warn("writing indirect symbol table from 0x{x} to 0x{x}", .{
dysymtab.indirectsymoff,
dysymtab.indirectsymoff + needed_size,
});
@ -2665,7 +2759,7 @@ fn writeStringTable(self: *Zld) !void {
symtab.strsize = @intCast(u32, mem.alignForwardGeneric(u64, self.strtab.items.len, @alignOf(u64)));
seg.inner.filesize += symtab.strsize;
log.debug("writing string table from 0x{x} to 0x{x}", .{ symtab.stroff, symtab.stroff + symtab.strsize });
log.warn("writing string table from 0x{x} to 0x{x}", .{ symtab.stroff, symtab.stroff + symtab.strsize });
try self.file.?.pwriteAll(self.strtab.items, symtab.stroff);
@ -2675,6 +2769,48 @@ fn writeStringTable(self: *Zld) !void {
}
}
fn writeDataInCode(self: *Zld) !void {
const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment;
const dice_cmd = &self.load_commands.items[self.data_in_code_cmd_index.?].LinkeditData;
const fileoff = seg.inner.fileoff + seg.inner.filesize;
var buf = std.ArrayList(u8).init(self.allocator);
defer buf.deinit();
const text_seg = self.load_commands.items[self.text_segment_cmd_index.?].Segment;
const text_sect = text_seg.sections.items[self.text_section_index.?];
for (self.objects.items) |object, object_id| {
const source_seg = object.load_commands.items[object.segment_cmd_index.?].Segment;
const source_sect = source_seg.sections.items[object.text_section_index.?];
const target_mapping = self.mappings.get(.{
.object_id = @intCast(u16, object_id),
.source_sect_id = object.text_section_index.?,
}) orelse continue;
// TODO Currently assume that Dice will always be within the __TEXT,__text section.
try buf.ensureCapacity(
buf.items.len + object.data_in_code_entries.items.len * @sizeOf(macho.data_in_code_entry),
);
for (object.data_in_code_entries.items) |dice| {
const new_dice: macho.data_in_code_entry = .{
.offset = text_sect.offset + target_mapping.offset + dice.offset - source_sect.offset,
.length = dice.length,
.kind = dice.kind,
};
buf.appendSliceAssumeCapacity(mem.asBytes(&new_dice));
}
}
const datasize = @intCast(u32, buf.items.len);
dice_cmd.dataoff = @intCast(u32, fileoff);
dice_cmd.datasize = datasize;
seg.inner.filesize += datasize;
log.warn("writing data-in-code from 0x{x} to 0x{x}", .{ fileoff, fileoff + datasize });
try self.file.?.pwriteAll(buf.items, fileoff);
}
fn writeCodeSignaturePadding(self: *Zld) !void {
const seg = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment;
const code_sig_cmd = &self.load_commands.items[self.code_signature_cmd_index.?].LinkeditData;
@ -2691,7 +2827,7 @@ fn writeCodeSignaturePadding(self: *Zld) !void {
seg.inner.filesize += needed_size;
seg.inner.vmsize = mem.alignForwardGeneric(u64, seg.inner.filesize, self.page_size.?);
log.debug("writing code signature padding from 0x{x} to 0x{x}", .{ fileoff, fileoff + needed_size });
log.warn("writing code signature padding from 0x{x} to 0x{x}", .{ fileoff, fileoff + needed_size });
// Pad out the space. We need to do this to calculate valid hashes for everything in the file
// except for code signature data.
@ -2717,7 +2853,7 @@ fn writeCodeSignature(self: *Zld) !void {
var stream = std.io.fixedBufferStream(buffer);
try code_sig.write(stream.writer());
log.debug("writing code signature from 0x{x} to 0x{x}", .{ code_sig_cmd.dataoff, code_sig_cmd.dataoff + buffer.len });
log.warn("writing code signature from 0x{x} to 0x{x}", .{ code_sig_cmd.dataoff, code_sig_cmd.dataoff + buffer.len });
try self.file.?.pwriteAll(buffer, code_sig_cmd.dataoff);
}
@ -2736,7 +2872,7 @@ fn writeLoadCommands(self: *Zld) !void {
}
const off = @sizeOf(macho.mach_header_64);
log.debug("writing {} load commands from 0x{x} to 0x{x}", .{ self.load_commands.items.len, off, off + sizeofcmds });
log.warn("writing {} load commands from 0x{x} to 0x{x}", .{ self.load_commands.items.len, off, off + sizeofcmds });
try self.file.?.pwriteAll(buffer, off);
}
@ -2774,7 +2910,7 @@ fn writeHeader(self: *Zld) !void {
for (self.load_commands.items) |cmd| {
header.sizeofcmds += cmd.cmdsize();
}
log.debug("writing Mach-O header {}", .{header});
log.warn("writing Mach-O header {}", .{header});
try self.file.?.pwriteAll(mem.asBytes(&header), 0);
}
@ -2788,7 +2924,7 @@ pub fn makeStaticString(bytes: []const u8) [16]u8 {
fn makeString(self: *Zld, bytes: []const u8) !u32 {
try self.strtab.ensureCapacity(self.allocator, self.strtab.items.len + bytes.len + 1);
const offset = @intCast(u32, self.strtab.items.len);
log.debug("writing new string '{s}' into string table at offset 0x{x}", .{ bytes, offset });
log.warn("writing new string '{s}' into string table at offset 0x{x}", .{ bytes, offset });
self.strtab.appendSliceAssumeCapacity(bytes);
self.strtab.appendAssumeCapacity(0);
return offset;