mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-02-13 12:59:04 +00:00
Code Issues Packages Projects Releases Wiki Activity

Move writing symbol table and export trie into functions

Browse Source
This commit is contained in:
Jakub Konka 2020-09-30 08:19:47 +02:00
parent ccf9bba61f
commit 635984abc7
1 changed files with 65 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

85
src/link/MachO.zig
View File

@ -236,33 +236,26 @@ pub fn flushModule(self: *MachO, comp: *Compilation) !void {
.Lib => return error.TODOImplementWritingLibFiles,
}
// Unfortunately these have to be buffered and done at the end because ELF does not allow
// mixing local and global symbols within a symbol table.
try self.writeExportTrie();
// Unfortunately these have to be buffered and done at the end because MachO does not allow
// mixing local, global and undefined symbols within a symbol table.
try self.writeAllGlobalSymbols();
try self.writeAllUndefSymbols();
try self.writeStringTable();
{
const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
symtab.nsyms = @intCast(u32, self.local_symbols.items.len + self.global_symbols.items.len + self.undef_symbols.items.len);
const allocated_size = self.allocatedSize(symtab.stroff);
const needed_size = self.string_table.items.len;
log.debug("allocated_size = 0x{x}, needed_size = 0x{x}\n", .{ allocated_size, needed_size });
if (needed_size > allocated_size) {
symtab.strsize = 0;
symtab.stroff = @intCast(u32, self.findFreeSpace(needed_size, 1));
}
symtab.strsize = @intCast(u32, needed_size);
log.debug("writing string table from 0x{x} to 0x{x}\n", .{ symtab.stroff, symtab.stroff + symtab.strsize });
try self.base.file.?.pwriteAll(self.string_table.items, symtab.stroff);
}
{
const dysymtab = &self.load_commands.items[self.dysymtab_cmd_index.?].Dysymtab;
// update Symtab and Dysymtab commands with symbol counts
// TODO this could probably be done incrementally
const nlocals = @intCast(u32, self.local_symbols.items.len);
const nglobals = @intCast(u32, self.global_symbols.items.len);
const nundefs = @intCast(u32, self.undef_symbols.items.len);
const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
symtab.nsyms = nlocals + nglobals + nundefs;
const dysymtab = &self.load_commands.items[self.dysymtab_cmd_index.?].Dysymtab;
dysymtab.nlocalsym = nlocals;
dysymtab.iextdefsym = nlocals;
dysymtab.nextdefsym = nglobals;
@ -1020,6 +1013,26 @@ pub fn populateMissingMetadata(self: *MachO) !void {
});
self.cmd_table_dirty = true;
}
if (self.dyld_info_cmd_index == null) {
self.dyld_info_cmd_index = @intCast(u16, self.load_commands.items.len);
try self.load_commands.append(self.base.allocator, .{
.DyldInfo = .{
.cmd = macho.LC_DYLD_INFO_ONLY,
.cmdsize = @sizeOf(macho.dyld_info_command),
.rebase_off = 0,
.rebase_size = 0,
.bind_off = 0,
.bind_size = 0,
.weak_bind_off = 0,
.weak_bind_size = 0,
.lazy_bind_off = 0,
.lazy_bind_size = 0,
.export_off = 0,
.export_size = 0,
},
});
self.cmd_table_dirty = true;
}
if (self.symtab_cmd_index == null) {
self.symtab_cmd_index = @intCast(u16, self.load_commands.items.len);
try self.load_commands.append(self.base.allocator, .{
@ -1366,6 +1379,38 @@ fn writeAllUndefSymbols(self: *MachO) !void {
try self.base.file.?.pwriteAll(mem.sliceAsBytes(self.undef_symbols.items), off);
}
fn writeExportTrie(self: *MachO) !void {
// TODO
// single branch export trie
var buf = [_]u8{0} ** 24;
buf[0] = 0; // root node
buf[1] = 1; // 1 branch from root
mem.copy(u8, buf[2..], "_start");
buf[8] = 0;
buf[9] = 9 + 1;
const written = try std.debug.leb.writeULEB128Mem(buf[12..], self.entry_addr.?);
buf[10] = @intCast(u8, written) + 1;
buf[11] = 0;
log.debug("WAT = {}, {x}\n", .{ written, buf[0..] });
}
fn writeStringTable(self: *MachO) !void {
const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
const allocated_size = self.allocatedSize(symtab.stroff);
const needed_size = self.string_table.items.len;
log.debug("allocated_size = 0x{x}, needed_size = 0x{x}\n", .{ allocated_size, needed_size });
if (needed_size > allocated_size) {
symtab.strsize = 0;
symtab.stroff = @intCast(u32, self.findFreeSpace(needed_size, 1));
}
symtab.strsize = @intCast(u32, needed_size);
log.debug("writing string table from 0x{x} to 0x{x}\n", .{ symtab.stroff, symtab.stroff + symtab.strsize });
try self.base.file.?.pwriteAll(self.string_table.items, symtab.stroff);
}
/// Writes Mach-O file header.
/// Should be invoked last as it needs up-to-date values of ncmds and sizeof_cmds bookkeeping
/// variables.