motiejus/zig
1
Fork 0
Code Releases Activity

macho: emit incomplete object file

Browse Source
This commit is contained in:
Jakub Konka
2024-02-01 12:13:46 +01:00
parent f2e249e920
commit 352941b030
2 changed files with 63 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files

59
src/link/MachO.zig
View File

@@ -285,8 +285,7 @@ pub fn createEmpty(
};
try self.d_sym.?.initMetadata(self);
} else {
try self.reportUnexpectedError("TODO: implement generating and emitting __DWARF in .o file", .{});
return error.Unexpected;
@panic("TODO: implement generating and emitting __DWARF in .o file");
},
.code_view => unreachable,
}
@@ -2025,7 +2024,7 @@ pub fn sortSections(self: *MachO) !void {
for (zo.symtab.items(.nlist)) |*sym| {
if (sym.sect()) {
sym.n_sect = backlinks[sym.n_sect];
sym.n_sect = backlinks[sym.n_sect - 1] + 1;
}
}
@@ -3391,8 +3390,6 @@ fn initMetadata(self: *MachO, options: InitMetadataOptions) !void {
.prot = macho.PROT.READ | macho.PROT.WRITE,
});
}
} else {
@panic("TODO initMetadata when relocatable");
}
const appendSect = struct {
@@ -3415,7 +3412,7 @@ fn initMetadata(self: *MachO, options: InitMetadataOptions) !void {
},
.flags = macho.S_REGULAR | macho.S_ATTR_PURE_INSTRUCTIONS | macho.S_ATTR_SOME_INSTRUCTIONS,
});
appendSect(self, self.zig_text_sect_index.?, self.zig_text_seg_index.?);
if (!self.base.isRelocatable()) appendSect(self, self.zig_text_sect_index.?, self.zig_text_seg_index.?);
}
if (!self.base.isRelocatable()) {
@@ -3427,33 +3424,35 @@ fn initMetadata(self: *MachO, options: InitMetadataOptions) !void {
{
self.zig_const_sect_index = try self.addSection("__CONST_ZIG", "__const_zig", .{});
appendSect(self, self.zig_const_sect_index.?, self.zig_const_seg_index.?);
if (!self.base.isRelocatable()) appendSect(self, self.zig_const_sect_index.?, self.zig_const_seg_index.?);
}
{
self.zig_data_sect_index = try self.addSection("__DATA_ZIG", "__data_zig", .{});
appendSect(self, self.zig_data_sect_index.?, self.zig_data_seg_index.?);
if (!self.base.isRelocatable()) appendSect(self, self.zig_data_sect_index.?, self.zig_data_seg_index.?);
}
{
self.zig_bss_sect_index = try self.addSection("__BSS_ZIG", "__bss_zig", .{
.flags = macho.S_ZEROFILL,
});
appendSect(self, self.zig_bss_sect_index.?, self.zig_bss_seg_index.?);
if (!self.base.isRelocatable()) appendSect(self, self.zig_bss_sect_index.?, self.zig_bss_seg_index.?);
}
}
pub fn growSection(self: *MachO, sect_index: u8, needed_size: u64) !void {
const sect = &self.sections.items(.header)[sect_index];
const seg_id = self.sections.items(.segment_id)[sect_index];
const seg = &self.segments.items[seg_id];
if (needed_size > self.allocatedSize(sect.offset) and !sect.isZerofill()) {
const existing_size = sect.size;
sect.size = 0;
// Must move the entire section.
const new_offset = self.findFreeSpace(needed_size, self.getPageSize());
const alignment = if (self.base.isRelocatable())
try math.powi(u32, 2, sect.@"align")
else
self.getPageSize();
const new_offset = self.findFreeSpace(needed_size, alignment);
log.debug("new '{s},{s}' file offset 0x{x} to 0x{x}", .{
sect.segName(),
@@ -3465,26 +3464,32 @@ pub fn growSection(self: *MachO, sect_index: u8, needed_size: u64) !void {
try self.copyRangeAllZeroOut(sect.offset, new_offset, existing_size);
sect.offset = @intCast(new_offset);
seg.fileoff = new_offset;
}
sect.size = needed_size;
if (!sect.isZerofill()) {
seg.filesize = needed_size;
}
const mem_capacity = self.allocatedVirtualSize(seg.vmaddr);
if (needed_size > mem_capacity) {
var err = try self.addErrorWithNotes(2);
try err.addMsg(self, "fatal linker error: cannot expand segment seg({d})({s}) in virtual memory", .{
seg_id,
seg.segName(),
});
try err.addNote(self, "TODO: emit relocations to memory locations in self-hosted backends", .{});
try err.addNote(self, "as a workaround, try increasing pre-allocated virtual memory of each segment", .{});
}
if (!self.base.isRelocatable()) {
const seg_id = self.sections.items(.segment_id)[sect_index];
const seg = &self.segments.items[seg_id];
seg.fileoff = sect.offset;
seg.vmsize = needed_size;
if (!sect.isZerofill()) {
seg.filesize = needed_size;
}
const mem_capacity = self.allocatedVirtualSize(seg.vmaddr);
if (needed_size > mem_capacity) {
var err = try self.addErrorWithNotes(2);
try err.addMsg(self, "fatal linker error: cannot expand segment seg({d})({s}) in virtual memory", .{
seg_id,
seg.segName(),
});
try err.addNote(self, "TODO: emit relocations to memory locations in self-hosted backends", .{});
try err.addNote(self, "as a workaround, try increasing pre-allocated virtual memory of each segment", .{});
}
seg.vmsize = needed_size;
}
}
pub fn getTarget(self: MachO) std.Target {

42
src/link/MachO/relocatable.zig
View File

@@ -12,7 +12,7 @@ pub fn flush(macho_file: *MachO, comp: *Compilation, module_obj_path: ?[]const u
if (module_obj_path) |path| try positionals.append(.{ .path = path });
if (positionals.items.len == 1) {
if (macho_file.getZigObject() == null and positionals.items.len == 1) {
// Instead of invoking a full-blown `-r` mode on the input which sadly will strip all
// debug info segments/sections (this is apparently by design by Apple), we copy
// the *only* input file over.
@@ -26,6 +26,11 @@ pub fn flush(macho_file: *MachO, comp: *Compilation, module_obj_path: ?[]const u
return;
}
if (macho_file.getZigObject() != null and positionals.items.len > 0) {
try macho_file.reportUnexpectedError("TODO: build-obj for ZigObject and input object files", .{});
return error.FlushFailure;
}
for (positionals.items) |obj| {
macho_file.parsePositional(obj.path, obj.must_link) catch |err| switch (err) {
error.MalformedObject,
@@ -46,8 +51,8 @@ pub fn flush(macho_file: *MachO, comp: *Compilation, module_obj_path: ?[]const u
try macho_file.addUndefinedGlobals();
try macho_file.resolveSymbols();
markExports(macho_file);
claimUnresolved(macho_file);
try markExports(macho_file);
try claimUnresolved(macho_file);
try initOutputSections(macho_file);
try macho_file.sortSections();
try macho_file.addAtomsToSections();
@@ -109,8 +114,13 @@ pub fn flush(macho_file: *MachO, comp: *Compilation, module_obj_path: ?[]const u
try writeHeader(macho_file, ncmds, sizeofcmds);
}
fn markExports(macho_file: *MachO) void {
for (macho_file.objects.items) |index| {
fn markExports(macho_file: *MachO) error{OutOfMemory}!void {
var objects = try std.ArrayList(File.Index).initCapacity(macho_file.base.comp.gpa, macho_file.objects.items.len + 1);
defer objects.deinit();
if (macho_file.getZigObject()) |zo| objects.appendAssumeCapacity(zo.index);
objects.appendSliceAssumeCapacity(macho_file.objects.items);
for (objects.items) |index| {
for (macho_file.getFile(index).?.getSymbols()) |sym_index| {
const sym = macho_file.getSymbol(sym_index);
const file = sym.getFile(macho_file) orelse continue;
@@ -122,13 +132,22 @@ fn markExports(macho_file: *MachO) void {
}
}
fn claimUnresolved(macho_file: *MachO) void {
for (macho_file.objects.items) |index| {
const object = macho_file.getFile(index).?.object;
fn claimUnresolved(macho_file: *MachO) error{OutOfMemory}!void {
var objects = try std.ArrayList(File.Index).initCapacity(macho_file.base.comp.gpa, macho_file.objects.items.len + 1);
defer objects.deinit();
if (macho_file.getZigObject()) |zo| objects.appendAssumeCapacity(zo.index);
objects.appendSliceAssumeCapacity(macho_file.objects.items);
for (object.symbols.items, 0..) |sym_index, i| {
for (objects.items) |index| {
const file = macho_file.getFile(index).?;
for (file.getSymbols(), 0..) |sym_index, i| {
const nlist_idx = @as(Symbol.Index, @intCast(i));
const nlist = object.symtab.items(.nlist)[nlist_idx];
const nlist = switch (file) {
.object => |x| x.symtab.items(.nlist)[nlist_idx],
.zig_object => |x| x.symtab.items(.nlist)[nlist_idx],
else => unreachable,
};
if (!nlist.ext()) continue;
if (!nlist.undf()) continue;
@@ -290,7 +309,7 @@ fn writeAtoms(macho_file: *MachO) !void {
assert(atom.flags.alive);
const off = math.cast(usize, atom.value - header.addr) orelse return error.Overflow;
const atom_size = math.cast(usize, atom.size) orelse return error.Overflow;
try atom.getFile(macho_file).object.getAtomData(atom.*, code[off..][0..atom_size]);
try atom.getData(macho_file, code[off..][0..atom_size]);
try atom.writeRelocs(macho_file, code[off..][0..atom_size], &relocs);
}
@@ -501,5 +520,6 @@ const trace = @import("../../tracy.zig").trace;
const Atom = @import("Atom.zig");
const Compilation = @import("../../Compilation.zig");
const File = @import("file.zig").File;
const MachO = @import("../MachO.zig");
const Symbol = @import("Symbol.zig");