Commit 6ac7e99dad
Changed files (1)
src
link
src/link/MachO.zig
@@ -322,33 +322,15 @@ pub fn flushModule(self: *MachO, comp: *Compilation) !void {
const tracy = trace(@src());
defer tracy.end();
- // 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();
switch (self.base.options.output_mode) {
.Exe => {
- // Write export trie.
- try self.writeExportTrie();
if (self.entry_addr) |addr| {
// Update LC_MAIN with entry offset.
const text_segment = self.load_commands.items[self.text_segment_cmd_index.?].Segment;
const main_cmd = &self.load_commands.items[self.main_cmd_index.?].EntryPoint;
main_cmd.entryoff = addr - text_segment.vmaddr;
}
- {
- // Update dynamic symbol table.
- 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 dysymtab = &self.load_commands.items[self.dysymtab_cmd_index.?].Dysymtab;
- dysymtab.nlocalsym = nlocals;
- dysymtab.iextdefsym = nlocals;
- dysymtab.nextdefsym = nglobals;
- dysymtab.iundefsym = nlocals + nglobals;
- dysymtab.nundefsym = nundefs;
- }
if (self.dylinker_cmd_dirty) {
// Write path to dyld loader.
var off: usize = @sizeOf(macho.mach_header_64);
@@ -375,27 +357,34 @@ pub fn flushModule(self: *MachO, comp: *Compilation) !void {
try self.base.file.?.pwriteAll(mem.spanZ(LIB_SYSTEM_PATH), off);
self.libsystem_cmd_dirty = false;
}
+
+ // Write export trie.
+ try self.writeExportTrie();
+ const linkedit = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment;
+ const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
+ const dyld_info = &self.load_commands.items[self.dyld_info_cmd_index.?].DyldInfo;
+ linkedit.fileoff = dyld_info.export_off;
+ symtab.symoff = dyld_info.export_off + dyld_info.export_size;
},
.Obj => {},
.Lib => return error.TODOImplementWritingLibFiles,
}
+ // 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.writeSymbolTable();
+ try self.writeStringTable();
+
{
- // Update symbol table.
- 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);
+ // TODO rework how we preallocate space for the entire __LINKEDIT segment instead of
+ // doing dynamic updates like this.
+ const linkedit = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment;
const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
- symtab.nsyms = nlocals + nglobals + nundefs;
- symtab.stroff = symtab.symoff + symtab.nsyms * @sizeOf(macho.nlist_64);
-
- // Extend dynamic linker info until start of symbol table
- const dyld_info = &self.load_commands.items[self.dyld_info_cmd_index.?].DyldInfo;
- dyld_info.export_size = symtab.symoff - dyld_info.export_off;
+ const file_size = symtab.stroff + symtab.strsize - linkedit.fileoff;
+ linkedit.filesize = file_size;
+ linkedit.vmsize = mem.alignForwardGeneric(u64, file_size, 0x1000);
}
- try self.writeStringTable();
-
if (self.cmd_table_dirty) {
try self.writeCmdHeaders();
try self.writeMachOHeader();
@@ -984,7 +973,7 @@ pub fn updateDecl(self: *MachO, module: *Module, decl: *Module.Decl) !void {
symbol.n_sect = @intCast(u8, self.text_section_index.?) + 1;
symbol.n_desc = 0;
// TODO this write could be avoided if no fields of the symbol were changed.
- try self.writeSymbol(decl.link.macho.local_sym_index);
+ // try self.writeSymbol(decl.link.macho.local_sym_index);
} else {
const decl_name = mem.spanZ(decl.name);
const name_str_index = try self.makeString(decl_name);
@@ -1001,7 +990,7 @@ pub fn updateDecl(self: *MachO, module: *Module, decl: *Module.Decl) !void {
};
self.offset_table.items[decl.link.macho.offset_table_index] = addr;
- try self.writeSymbol(decl.link.macho.local_sym_index);
+ // try self.writeSymbol(decl.link.macho.local_sym_index);
try self.writeOffsetTableEntry(decl.link.macho.offset_table_index);
}
@@ -1399,48 +1388,6 @@ pub fn populateMissingMetadata(self: *MachO) !void {
},
});
}
- {
- const linkedit = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment;
- const dyld_info = &self.load_commands.items[self.dyld_info_cmd_index.?].DyldInfo;
- if (dyld_info.export_off == 0) {
- const nsyms = self.base.options.symbol_count_hint;
- const file_size = @sizeOf(u64) * nsyms;
- const off = @intCast(u32, self.findFreeSpace(file_size, 0x1000));
- log.debug("found export trie free space 0x{x} to 0x{x}\n", .{ off, off + file_size });
- dyld_info.export_off = off;
- dyld_info.export_size = @intCast(u32, file_size);
-
- const segment_size = mem.alignForwardGeneric(u64, file_size, 0x1000);
- linkedit.vmsize += segment_size;
- linkedit.fileoff = off;
- }
- }
- {
- const linkedit = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment;
- const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
- if (symtab.symoff == 0) {
- const nsyms = self.base.options.symbol_count_hint;
- const file_size = @sizeOf(macho.nlist_64) * nsyms;
- const off = @intCast(u32, self.findFreeSpace(file_size, 0x1000));
- log.debug("found symbol table free space 0x{x} to 0x{x}\n", .{ off, off + file_size });
- symtab.symoff = off;
- symtab.nsyms = @intCast(u32, nsyms);
-
- const segment_size = mem.alignForwardGeneric(u64, file_size, 0x1000);
- linkedit.vmsize += segment_size;
- }
- if (symtab.stroff == 0) {
- try self.string_table.append(self.base.allocator, 0);
- const file_size = @intCast(u32, self.string_table.items.len);
- const off = @intCast(u32, self.findFreeSpace(file_size, 0x1000));
- log.debug("found string table free space 0x{x} to 0x{x}\n", .{ off, off + file_size });
- symtab.stroff = off;
- symtab.strsize = file_size;
-
- const segment_size = mem.alignForwardGeneric(u64, file_size, 0x1000);
- linkedit.vmsize += segment_size;
- }
- }
if (self.dyld_stub_binder_index == null) {
self.dyld_stub_binder_index = @intCast(u16, self.undef_symbols.items.len);
const name = try self.makeString("dyld_stub_binder");
@@ -1687,6 +1634,53 @@ fn writeOffsetTableEntry(self: *MachO, index: usize) !void {
try self.base.file.?.pwriteAll(&buf, off);
}
+fn writeSymbolTable(self: *MachO) !void {
+ const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
+ const locals_off = symtab.symoff;
+
+ var locals = try self.base.allocator.alloc(macho.nlist_64, self.local_symbols.items.len - 1);
+ defer self.base.allocator.free(locals);
+
+ for (locals) |*sym, i| {
+ sym.* = .{
+ .n_strx = self.local_symbols.items[i + 1].n_strx,
+ .n_type = self.local_symbols.items[i + 1].n_type,
+ .n_sect = self.local_symbols.items[i + 1].n_sect,
+ .n_desc = self.local_symbols.items[i + 1].n_desc,
+ .n_value = self.local_symbols.items[i + 1].n_value,
+ };
+ }
+
+ const locals_size = locals.len * @sizeOf(macho.nlist_64);
+ log.debug("writing local symbols from 0x{x} to 0x{x}\n", .{ locals_off, locals_size + locals_off });
+ try self.base.file.?.pwriteAll(mem.sliceAsBytes(locals), locals_off);
+
+ const globals_off = locals_off + locals_size;
+ const globals_size = self.global_symbols.items.len * @sizeOf(macho.nlist_64);
+ log.debug("writing global symbols from 0x{x} to 0x{x}\n", .{ globals_off, globals_size + globals_off });
+ try self.base.file.?.pwriteAll(mem.sliceAsBytes(self.global_symbols.items), globals_off);
+
+ const undefs_off = globals_off + globals_size;
+ const undefs_size = self.undef_symbols.items.len * @sizeOf(macho.nlist_64);
+ log.debug("writing undef symbols from 0x{x} to 0x{x}\n", .{ undefs_off, undefs_size + undefs_off });
+ try self.base.file.?.pwriteAll(mem.sliceAsBytes(self.undef_symbols.items), undefs_off);
+
+ // Update symbol table.
+ const nlocals = @intCast(u32, locals.len);
+ const nglobals = @intCast(u32, self.global_symbols.items.len);
+ const nundefs = @intCast(u32, self.undef_symbols.items.len);
+ symtab.nsyms = nlocals + nglobals + nundefs;
+ symtab.stroff = symtab.symoff + symtab.nsyms * @sizeOf(macho.nlist_64);
+
+ // Update dynamic symbol table.
+ const dysymtab = &self.load_commands.items[self.dysymtab_cmd_index.?].Dysymtab;
+ dysymtab.nlocalsym = nlocals;
+ dysymtab.iextdefsym = nlocals;
+ dysymtab.nextdefsym = nglobals;
+ dysymtab.iundefsym = nlocals + nglobals;
+ dysymtab.nundefsym = nundefs;
+}
+
fn writeAllGlobalSymbols(self: *MachO) !void {
const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
const off = symtab.symoff + self.local_symbols.items.len * @sizeOf(macho.nlist_64);
@@ -1728,29 +1722,26 @@ fn writeExportTrie(self: *MachO) !void {
try trie.writeULEB128Mem(self.base.allocator, &buffer);
+ const data = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
const dyld_info = &self.load_commands.items[self.dyld_info_cmd_index.?].DyldInfo;
+ dyld_info.export_off = @intCast(u32, data.fileoff + data.filesize);
+ dyld_info.export_size = mem.alignForwardGeneric(u32, @intCast(u32, buffer.items.len), @sizeOf(u64));
try self.base.file.?.pwriteAll(buffer.items, dyld_info.export_off);
}
fn writeStringTable(self: *MachO) !void {
const symtab = &self.load_commands.items[self.symtab_cmd_index.?].Symtab;
- const allocated_size = self.allocatedSize(symtab.stroff);
+ // const allocated_size = self.allocatedSize(symtab.stroff);
const needed_size = self.string_table.items.len;
- 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 });
-
+ // if (needed_size > allocated_size) {
+ // symtab.strsize = 0;
+ // symtab.stroff = @intCast(u32, self.findFreeSpace(needed_size, 1));
+ // }
+ symtab.strsize = mem.alignForwardGeneric(u32, @intCast(u32, needed_size), @sizeOf(u64));
+ try self.base.file.?.pwriteAll(&[_]u8{ 0 }, symtab.stroff + symtab.strsize - 1);
+ log.debug("writing string table from 0x{x} to 0x{x}\n", .{ symtab.stroff, symtab.stroff + needed_size });
try self.base.file.?.pwriteAll(self.string_table.items, symtab.stroff);
-
- // TODO rework how we preallocate space for the entire __LINKEDIT segment instead of
- // doing dynamic updates like this.
- const linkedit = &self.load_commands.items[self.linkedit_segment_cmd_index.?].Segment;
- linkedit.filesize = symtab.stroff + symtab.strsize - linkedit.fileoff;
}
fn writeCmdHeaders(self: *MachO) !void {