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macho: define __mh_execute_header as a linker synthetic global

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Jakub Konka
2021-11-26 17:04:04 +01:00
parent 8317dbd1cb
commit a956958ba9
1 changed files with 38 additions and 0 deletions
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38
src/link/MachO.zig
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@@ -154,6 +154,7 @@ tentatives: std.AutoArrayHashMapUnmanaged(u32, void) = .{},
locals_free_list: std.ArrayListUnmanaged(u32) = .{},
globals_free_list: std.ArrayListUnmanaged(u32) = .{},
mh_execute_header_index: ?u32 = null,
dyld_stub_binder_index: ?u32 = null,
dyld_private_atom: ?*Atom = null,
stub_helper_preamble_atom: ?*Atom = null,
@@ -863,6 +864,7 @@ pub fn flushModule(self: *MachO, comp: *Compilation) !void {
sect.offset = self.tlv_bss_file_offset;
}
try self.createMhExecuteHeaderAtom();
for (self.objects.items) |*object, object_id| {
if (object.analyzed) continue;
try self.resolveSymbolsInObject(@intCast(u16, object_id));
@@ -2725,6 +2727,42 @@ fn resolveSymbolsInDylibs(self: *MachO) !void {
}
}
fn createMhExecuteHeaderAtom(self: *MachO) !void {
if (self.mh_execute_header_index != null) return;
const match: MatchingSection = .{
.seg = self.text_segment_cmd_index.?,
.sect = self.text_section_index.?,
};
const n_strx = try self.makeString("__mh_execute_header");
const local_sym_index = @intCast(u32, self.locals.items.len);
var nlist = macho.nlist_64{
.n_strx = n_strx,
.n_type = macho.N_SECT,
.n_sect = @intCast(u8, self.section_ordinals.getIndex(match).? + 1),
.n_desc = 0,
.n_value = 0,
};
try self.locals.append(self.base.allocator, nlist);
nlist.n_type |= macho.N_EXT;
const global_sym_index = @intCast(u32, self.globals.items.len);
try self.globals.append(self.base.allocator, nlist);
try self.symbol_resolver.putNoClobber(self.base.allocator, n_strx, .{
.where = .global,
.where_index = global_sym_index,
.local_sym_index = local_sym_index,
.file = null,
});
const atom = try self.createEmptyAtom(local_sym_index, 0, 0);
const sym = &self.locals.items[local_sym_index];
const vaddr = try self.allocateAtom(atom, 0, 1, match);
sym.n_value = vaddr;
atom.dirty = false;
self.mh_execute_header_index = local_sym_index;
}
fn resolveDyldStubBinder(self: *MachO) !void {
if (self.dyld_stub_binder_index != null) return;