mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-02-21 16:54:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

macho: do not write null symbols into undef symbols section

Browse Source 
Also, skip creating stub entries for resolved globally defined
regular symbols.
This commit is contained in:
Jakub Konka 2021-12-08 12:42:03 +01:00
parent 83a6681955
commit f0ec70edd1
2 changed files with 27 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
src/link/MachO.zig
View File

@ -5400,6 +5400,21 @@ fn writeSymbolTable(self: *MachO) !void {
try locals.append(sym);
}
// TODO How do we handle null global symbols in incremental context?
var undefs = std.ArrayList(macho.nlist_64).init(self.base.allocator);
defer undefs.deinit();
var undefs_table = std.AutoHashMap(u32, u32).init(self.base.allocator);
defer undefs_table.deinit();
try undefs.ensureTotalCapacity(self.undefs.items.len);
try undefs_table.ensureTotalCapacity(@intCast(u32, self.undefs.items.len));
for (self.undefs.items) |sym, i| {
if (sym.n_strx == 0) continue;
const new_index = @intCast(u32, undefs.items.len);
undefs.appendAssumeCapacity(sym);
undefs_table.putAssumeCapacityNoClobber(@intCast(u32, i), new_index);
}
if (self.has_stabs) {
for (self.objects.items) |object| {
if (object.debug_info == null) continue;
@ -5456,7 +5471,7 @@ fn writeSymbolTable(self: *MachO) !void {
const nlocals = locals.items.len;
const nexports = self.globals.items.len;
const nundefs = self.undefs.items.len;
const nundefs = undefs.items.len;
const locals_off = symtab.symoff;
const locals_size = nlocals * @sizeOf(macho.nlist_64);
@ -5471,7 +5486,7 @@ fn writeSymbolTable(self: *MachO) !void {
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 });
try self.base.file.?.pwriteAll(mem.sliceAsBytes(self.undefs.items), undefs_off);
try self.base.file.?.pwriteAll(mem.sliceAsBytes(undefs.items), undefs_off);
symtab.nsyms = @intCast(u32, nlocals + nexports + nundefs);
seg.inner.filesize += locals_size + exports_size + undefs_size;
@ -5513,10 +5528,10 @@ fn writeSymbolTable(self: *MachO) !void {
stubs.reserved1 = 0;
for (self.stubs_map.keys()) |key| {
const resolv = self.symbol_resolver.get(key) orelse continue;
const resolv = self.symbol_resolver.get(key).?;
switch (resolv.where) {
.global => try writer.writeIntLittle(u32, macho.INDIRECT_SYMBOL_LOCAL),
.undef => try writer.writeIntLittle(u32, dysymtab.iundefsym + resolv.where_index),
.undef => try writer.writeIntLittle(u32, dysymtab.iundefsym + undefs_table.get(resolv.where_index).?),
}
}
@ -5525,10 +5540,10 @@ fn writeSymbolTable(self: *MachO) !void {
switch (key) {
.local => try writer.writeIntLittle(u32, macho.INDIRECT_SYMBOL_LOCAL),
.global => |n_strx| {
const resolv = self.symbol_resolver.get(n_strx) orelse continue;
const resolv = self.symbol_resolver.get(n_strx).?;
switch (resolv.where) {
.global => try writer.writeIntLittle(u32, macho.INDIRECT_SYMBOL_LOCAL),
.undef => try writer.writeIntLittle(u32, dysymtab.iundefsym + resolv.where_index),
.undef => try writer.writeIntLittle(u32, dysymtab.iundefsym + undefs_table.get(resolv.where_index).?),
}
},
}
@ -5536,10 +5551,10 @@ fn writeSymbolTable(self: *MachO) !void {
la_symbol_ptr.reserved1 = got.reserved1 + ngot_entries;
for (self.stubs_map.keys()) |key| {
const resolv = self.symbol_resolver.get(key) orelse continue;
const resolv = self.symbol_resolver.get(key).?;
switch (resolv.where) {
.global => try writer.writeIntLittle(u32, macho.INDIRECT_SYMBOL_LOCAL),
.undef => try writer.writeIntLittle(u32, dysymtab.iundefsym + resolv.where_index),
.undef => try writer.writeIntLittle(u32, dysymtab.iundefsym + undefs_table.get(resolv.where_index).?),
}
}

4
src/link/MachO/Atom.zig
View File

@ -571,6 +571,10 @@ fn addGotEntry(target: Relocation.Target, context: RelocContext) !void {
fn addStub(target: Relocation.Target, context: RelocContext) !void {
if (target != .global) return;
if (context.macho_file.stubs_map.contains(target.global)) return;
// If the symbol has been resolved as defined globally elsewhere (in a different translation unit),
// then skip creating stub entry.
// TODO Is this the correct for the incremental?
if (context.macho_file.symbol_resolver.get(target.global).?.where == .global) return;
const value_ptr = blk: {
if (context.macho_file.stubs_map_free_list.popOrNull()) |i| {