Commit 5a2bea2931
Changed files (2)
src
link
MachO
src/link/MachO/Object.zig
@@ -56,9 +56,6 @@ tu_name: ?[]const u8 = null,
tu_comp_dir: ?[]const u8 = null,
mtime: ?u64 = null,
-symbols: std.ArrayListUnmanaged(*Symbol) = .{},
-sections_as_symbols: std.AutoHashMapUnmanaged(u8, *Symbol) = .{},
-
text_blocks: std.ArrayListUnmanaged(*TextBlock) = .{},
const DebugInfo = struct {
@@ -165,8 +162,6 @@ pub fn deinit(self: *Object) void {
self.data_in_code_entries.deinit(self.allocator);
self.symtab.deinit(self.allocator);
self.strtab.deinit(self.allocator);
- self.symbols.deinit(self.allocator);
- self.sections_as_symbols.deinit(self.allocator);
self.text_blocks.deinit(self.allocator);
if (self.debug_info) |*db| {
src/link/MachO/Zld.zig
@@ -16,7 +16,6 @@ const Archive = @import("Archive.zig");
const CodeSignature = @import("CodeSignature.zig");
const Dylib = @import("Dylib.zig");
const Object = @import("Object.zig");
-const Symbol = @import("Symbol.zig");
const TextBlock = @import("TextBlock.zig");
const Trie = @import("Trie.zig");
@@ -100,22 +99,55 @@ objc_selrefs_section_index: ?u16 = null,
objc_classrefs_section_index: ?u16 = null,
objc_data_section_index: ?u16 = null,
-locals: std.ArrayListUnmanaged(*Symbol) = .{},
-imports: std.ArrayListUnmanaged(*Symbol) = .{},
-globals: std.StringArrayHashMapUnmanaged(*Symbol) = .{},
+locals: std.ArrayListUnmanaged(macho.nlist_64) = .{},
+globals: std.ArrayListUnmanaged(macho.nlist_64) = .{},
+imports: std.ArrayListUnmanaged(macho.nlist_64) = .{},
+undefs: std.ArrayListUnmanaged(macho.nlist_64) = .{},
+tentatives: std.ArrayListUnmanaged(macho.nlist_64) = .{},
+symbol_resolver: std.StringArrayHashMapUnmanaged(SymbolWithLoc) = .{},
+object_mapping: std.AutoHashMapUnmanaged(u16, []u32) = .{},
-stubs: std.ArrayListUnmanaged(*Symbol) = .{},
-got_entries: std.ArrayListUnmanaged(*Symbol) = .{},
+strtab: std.ArrayListUnmanaged(u8) = .{},
+
+// stubs: std.ArrayListUnmanaged(*Symbol) = .{},
+got_entries: std.ArrayListUnmanaged(GotEntry) = .{},
stub_helper_stubs_start_off: ?u64 = null,
blocks: std.AutoHashMapUnmanaged(MatchingSection, *TextBlock) = .{},
-strtab: std.ArrayListUnmanaged(u8) = .{},
-
has_dices: bool = false,
has_stabs: bool = false,
+const SymbolWithLoc = struct {
+ // Table where the symbol can be found.
+ where: enum {
+ global,
+ import,
+ undef,
+ tentative,
+ },
+ where_index: u32,
+ local_sym_index: u32 = 0,
+ file: u16 = 0,
+};
+
+pub const GotEntry = struct {
+ /// GOT entry can either be a local pointer or an extern (nonlazy) import.
+ kind: enum {
+ local,
+ import,
+ },
+
+ /// Id to the macho.nlist_64 from the respective table: either locals or nonlazy imports.
+ /// TODO I'm more and more inclined to just manage a single, max two symbol tables
+ /// rather than 4 as we currently do, but I'll follow up in the future PR.
+ local_sym_index: u32,
+
+ /// Index of this entry in the GOT.
+ got_index: u32,
+};
+
pub const Output = struct {
tag: enum { exe, dylib },
path: []const u8,
@@ -130,7 +162,7 @@ pub fn init(allocator: *Allocator) !Zld {
}
pub fn deinit(self: *Zld) void {
- self.stubs.deinit(self.allocator);
+ // self.stubs.deinit(self.allocator);
self.got_entries.deinit(self.allocator);
for (self.load_commands.items) |*lc| {
@@ -156,20 +188,24 @@ pub fn deinit(self: *Zld) void {
}
self.dylibs.deinit(self.allocator);
- for (self.imports.items) |sym| {
- self.allocator.destroy(sym);
- }
+ self.locals.deinit(self.allocator);
+ self.globals.deinit(self.allocator);
self.imports.deinit(self.allocator);
+ self.undefs.deinit(self.allocator);
+ self.tentatives.deinit(self.allocator);
- for (self.locals.items) |sym| {
- self.allocator.destroy(sym);
+ for (self.symbol_resolver.keys()) |key| {
+ self.allocator.free(key);
}
- self.locals.deinit(self.allocator);
+ self.symbol_resolver.deinit(self.allocator);
- for (self.globals.keys()) |key| {
- self.allocator.free(key);
+ {
+ var it = self.object_mapping.valueIterator();
+ while (it.next()) |value_ptr| {
+ self.allocator.free(value_ptr.*);
+ }
}
- self.globals.deinit(self.allocator);
+ self.object_mapping.deinit(self.allocator);
self.strtab.deinit(self.allocator);
@@ -213,28 +249,73 @@ pub fn link(self: *Zld, files: []const []const u8, output: Output, args: LinkArg
try self.parseInputFiles(files, args.syslibroot);
try self.parseLibs(args.libs, args.syslibroot);
try self.resolveSymbols();
- try self.parseTextBlocks();
- try self.sortSections();
- try self.addRpaths(args.rpaths);
- try self.addDataInCodeLC();
- try self.addCodeSignatureLC();
- try self.allocateTextSegment();
- try self.allocateDataConstSegment();
- try self.allocateDataSegment();
- self.allocateLinkeditSegment();
- try self.allocateTextBlocks();
-
- // var it = self.blocks.iterator();
- // while (it.next()) |entry| {
- // const seg = self.load_commands.items[entry.key_ptr.seg].Segment;
- // const sect = seg.sections.items[entry.key_ptr.sect];
-
- // log.warn("\n\n{s},{s} contents:", .{ segmentName(sect), sectionName(sect) });
- // log.warn(" {}", .{sect});
- // entry.value_ptr.*.print(self);
- // }
-
- try self.flush();
+
+ log.warn("locals", .{});
+ for (self.locals.items) |sym| {
+ log.warn(" | {s}: {}", .{ self.getString(sym.n_strx), sym });
+ }
+
+ log.warn("globals", .{});
+ for (self.globals.items) |sym| {
+ log.warn(" | {s}: {}", .{ self.getString(sym.n_strx), sym });
+ }
+
+ log.warn("tentatives", .{});
+ for (self.tentatives.items) |sym| {
+ log.warn(" | {s}: {}", .{ self.getString(sym.n_strx), sym });
+ }
+
+ log.warn("undefines", .{});
+ for (self.undefs.items) |sym| {
+ log.warn(" | {s}: {}", .{ self.getString(sym.n_strx), sym });
+ }
+
+ log.warn("imports", .{});
+ for (self.imports.items) |sym| {
+ log.warn(" | {s}: {}", .{ self.getString(sym.n_strx), sym });
+ }
+
+ log.warn("symbol resolver", .{});
+ for (self.symbol_resolver.keys()) |key| {
+ log.warn(" | {s} => {}", .{ key, self.symbol_resolver.get(key).? });
+ }
+
+ log.warn("mappings", .{});
+ for (self.objects.items) |object, id| {
+ const object_id = @intCast(u16, id);
+ log.warn(" in object {s}", .{object.name.?});
+ for (object.symtab.items) |sym, sym_id| {
+ if (self.localSymIndex(object_id, @intCast(u32, sym_id))) |local_id| {
+ log.warn(" | {d} => {d}", .{ sym_id, local_id });
+ } else {
+ log.warn(" | {d} no local mapping for {s}", .{ sym_id, object.getString(sym.n_strx) });
+ }
+ }
+ }
+
+ return error.TODO;
+ // try self.parseTextBlocks();
+ // try self.sortSections();
+ // try self.addRpaths(args.rpaths);
+ // try self.addDataInCodeLC();
+ // try self.addCodeSignatureLC();
+ // try self.allocateTextSegment();
+ // try self.allocateDataConstSegment();
+ // try self.allocateDataSegment();
+ // self.allocateLinkeditSegment();
+ // try self.allocateTextBlocks();
+
+ // // var it = self.blocks.iterator();
+ // // while (it.next()) |entry| {
+ // // const seg = self.load_commands.items[entry.key_ptr.seg].Segment;
+ // // const sect = seg.sections.items[entry.key_ptr.sect];
+
+ // // log.warn("\n\n{s},{s} contents:", .{ segmentName(sect), sectionName(sect) });
+ // // log.warn(" {}", .{sect});
+ // // entry.value_ptr.*.print(self);
+ // // }
+
+ // try self.flush();
}
fn parseInputFiles(self: *Zld, files: []const []const u8, syslibroot: ?[]const u8) !void {
@@ -1328,130 +1409,242 @@ fn writeStubInStubHelper(self: *Zld, index: u32) !void {
try self.file.?.pwriteAll(code, stub_off);
}
-fn resolveSymbolsInObject(self: *Zld, object: *Object) !void {
- log.debug("resolving symbols in '{s}'", .{object.name});
+fn resolveSymbolsInObject(self: *Zld, object_id: u16) !void {
+ const object = self.objects.items[object_id];
+
+ log.warn("resolving symbols in '{s}'", .{object.name});
+
+ const mapping = try self.allocator.alloc(u32, object.symtab.items.len);
+ mem.set(u32, mapping, 0);
+ try self.object_mapping.putNoClobber(self.allocator, object_id, mapping);
- for (object.symtab.items) |sym| {
+ for (object.symtab.items) |sym, id| {
+ const sym_id = @intCast(u32, id);
const sym_name = object.getString(sym.n_strx);
- if (Symbol.isStab(sym)) {
- log.err("unhandled symbol type: stab {s}", .{sym_name});
- log.err(" | first definition in {s}", .{object.name.?});
+ if (symbolIsStab(sym)) {
+ log.err("unhandled symbol type: stab", .{});
+ log.err(" symbol '{s}'", .{sym_name});
+ log.err(" first definition in '{s}'", .{object.name.?});
return error.UnhandledSymbolType;
}
- if (Symbol.isIndr(sym)) {
- log.err("unhandled symbol type: indirect {s}", .{sym_name});
- log.err(" | first definition in {s}", .{object.name.?});
+ if (symbolIsIndr(sym)) {
+ log.err("unhandled symbol type: indirect", .{});
+ log.err(" symbol '{s}'", .{sym_name});
+ log.err(" first definition in '{s}'", .{object.name.?});
return error.UnhandledSymbolType;
}
- if (Symbol.isAbs(sym)) {
- log.err("unhandled symbol type: absolute {s}", .{sym_name});
- log.err(" | first definition in {s}", .{object.name.?});
+ if (symbolIsAbs(sym)) {
+ log.err("unhandled symbol type: absolute", .{});
+ log.err(" symbol '{s}'", .{sym_name});
+ log.err(" first definition in '{s}'", .{object.name.?});
return error.UnhandledSymbolType;
}
- if (Symbol.isSect(sym) and !Symbol.isExt(sym)) {
- // Regular symbol local to translation unit
- const symbol = try self.allocator.create(Symbol);
- symbol.* = .{
- .strx = try self.makeString(sym_name),
- .payload = .{
- .regular = .{
- .linkage = .translation_unit,
- .address = sym.n_value,
- .weak_ref = Symbol.isWeakRef(sym),
- .file = object,
- .local_sym_index = @intCast(u32, self.locals.items.len),
- },
- },
+ if (symbolIsSect(sym)) {
+ // Defined symbol regardless of scope lands in the locals symbol table.
+ const n_strx = blk: {
+ if (self.symbol_resolver.get(sym_name)) |resolv| {
+ switch (resolv.where) {
+ .global => break :blk self.globals.items[resolv.where_index].n_strx,
+ .tentative => break :blk self.tentatives.items[resolv.where_index].n_strx,
+ .undef => break :blk self.undefs.items[resolv.where_index].n_strx,
+ .import => unreachable,
+ }
+ }
+ break :blk try self.makeString(sym_name);
};
- try self.locals.append(self.allocator, symbol);
- try object.symbols.append(self.allocator, symbol);
- continue;
- }
-
- const symbol = self.globals.get(sym_name) orelse symbol: {
- // Insert new global symbol.
- const symbol = try self.allocator.create(Symbol);
- symbol.* = .{
- .strx = try self.makeString(sym_name),
- .payload = .{ .undef = .{ .file = object } },
+ const local_sym_index = @intCast(u32, self.locals.items.len);
+ try self.locals.append(self.allocator, .{
+ .n_strx = n_strx,
+ .n_type = macho.N_SECT,
+ .n_sect = 0,
+ .n_desc = 0,
+ .n_value = sym.n_value,
+ });
+ mapping[sym_id] = local_sym_index;
+
+ // If the symbol's scope is not local aka translation unit, then we need work out
+ // if we should save the symbol as a global, or potentially flag the error.
+ if (!symbolIsExt(sym)) continue;
+
+ const local = self.locals.items[local_sym_index];
+ const resolv = self.symbol_resolver.getPtr(sym_name) orelse {
+ const global_sym_index = @intCast(u32, self.globals.items.len);
+ try self.globals.append(self.allocator, .{
+ .n_strx = n_strx,
+ .n_type = sym.n_type,
+ .n_sect = 0,
+ .n_desc = sym.n_desc,
+ .n_value = sym.n_value,
+ });
+ try self.symbol_resolver.putNoClobber(self.allocator, try self.allocator.dupe(u8, sym_name), .{
+ .where = .global,
+ .where_index = global_sym_index,
+ .local_sym_index = local_sym_index,
+ .file = object_id,
+ });
+ continue;
};
- const alloc_name = try self.allocator.dupe(u8, sym_name);
- try self.globals.putNoClobber(self.allocator, alloc_name, symbol);
- break :symbol symbol;
- };
- if (Symbol.isSect(sym)) {
- // Global symbol
- const linkage: Symbol.Regular.Linkage = if (Symbol.isWeakDef(sym) or Symbol.isPext(sym))
- .linkage_unit
- else
- .global;
-
- const should_update = if (symbol.payload == .regular) blk: {
- if (symbol.payload.regular.linkage == .global and linkage == .global) {
- log.err("symbol '{s}' defined multiple times", .{sym_name});
- log.err(" | first definition in {s}", .{symbol.payload.regular.file.?.name.?});
- log.err(" | next definition in {s}", .{object.name.?});
- return error.MultipleSymbolDefinitions;
- }
- break :blk symbol.payload.regular.linkage != .global;
- } else true;
-
- if (should_update) {
- symbol.payload = .{
- .regular = .{
- .linkage = linkage,
- .address = sym.n_value,
- .weak_ref = Symbol.isWeakRef(sym),
- .file = object,
- },
- };
+ switch (resolv.where) {
+ .import => unreachable,
+ .global => {
+ const global = &self.globals.items[resolv.where_index];
+
+ if (!(symbolIsWeakDef(sym) and symbolIsPext(sym)) and
+ !(symbolIsWeakDef(global.*) and symbolIsPext(global.*)))
+ {
+ log.err("symbol '{s}' defined multiple times", .{sym_name});
+ log.err(" first definition in '{s}'", .{self.objects.items[resolv.file].name.?});
+ log.err(" next definition in '{s}'", .{object.name.?});
+ return error.MultipleSymbolDefinitions;
+ }
+
+ if (symbolIsWeakDef(sym) or symbolIsPext(sym)) continue; // Current symbol is weak, so skip it.
+
+ // Otherwise, update the resolver and the global symbol.
+ global.n_type = sym.n_type;
+ resolv.local_sym_index = local_sym_index;
+ resolv.file = object_id;
+
+ continue;
+ },
+ .undef => {
+ const undef = &self.undefs.items[resolv.where_index];
+ undef.* = .{
+ .n_strx = 0,
+ .n_type = macho.N_UNDF,
+ .n_sect = 0,
+ .n_desc = 0,
+ .n_value = 0,
+ };
+ },
+ .tentative => {
+ const tentative = &self.tentatives.items[resolv.where_index];
+ tentative.* = .{
+ .n_strx = 0,
+ .n_type = macho.N_UNDF,
+ .n_sect = 0,
+ .n_desc = 0,
+ .n_value = 0,
+ };
+ },
}
- } else if (sym.n_value != 0) {
- // Tentative definition
- const should_update = switch (symbol.payload) {
- .tentative => |tent| tent.size < sym.n_value,
- .undef => true,
- else => false,
+
+ const global_sym_index = @intCast(u32, self.globals.items.len);
+ try self.globals.append(self.allocator, .{
+ .n_strx = local.n_strx,
+ .n_type = sym.n_type,
+ .n_sect = 0,
+ .n_desc = sym.n_desc,
+ .n_value = sym.n_value,
+ });
+ resolv.* = .{
+ .where = .global,
+ .where_index = global_sym_index,
+ .local_sym_index = local_sym_index,
+ .file = object_id,
+ };
+ } else if (symbolIsTentative(sym)) {
+ // Symbol is a tentative definition.
+ const resolv = self.symbol_resolver.getPtr(sym_name) orelse {
+ const tent_sym_index = @intCast(u32, self.tentatives.items.len);
+ try self.tentatives.append(self.allocator, .{
+ .n_strx = try self.makeString(sym_name),
+ .n_type = sym.n_type,
+ .n_sect = 0,
+ .n_desc = sym.n_desc,
+ .n_value = sym.n_value,
+ });
+ try self.symbol_resolver.putNoClobber(self.allocator, try self.allocator.dupe(u8, sym_name), .{
+ .where = .tentative,
+ .where_index = tent_sym_index,
+ .file = object_id,
+ });
+ continue;
};
- if (should_update) {
- symbol.payload = .{
- .tentative = .{
- .size = sym.n_value,
- .alignment = (sym.n_desc >> 8) & 0x0f,
- .file = object,
- },
- };
+ switch (resolv.where) {
+ .import => unreachable,
+ .global => {},
+ .undef => {
+ const undef = &self.undefs.items[resolv.where_index];
+ const tent_sym_index = @intCast(u32, self.tentatives.items.len);
+ try self.tentatives.append(self.allocator, .{
+ .n_strx = undef.n_strx,
+ .n_type = sym.n_type,
+ .n_sect = 0,
+ .n_desc = sym.n_desc,
+ .n_value = sym.n_value,
+ });
+ resolv.* = .{
+ .where = .tentative,
+ .where_index = tent_sym_index,
+ .file = object_id,
+ };
+ undef.* = .{
+ .n_strx = 0,
+ .n_type = macho.N_UNDF,
+ .n_sect = 0,
+ .n_desc = 0,
+ .n_value = 0,
+ };
+ },
+ .tentative => {
+ const tentative = &self.tentatives.items[resolv.where_index];
+ if (tentative.n_value >= sym.n_value) continue;
+
+ tentative.n_desc = sym.n_desc;
+ tentative.n_value = sym.n_value;
+ resolv.file = object_id;
+ },
}
- }
+ } else {
+ // Symbol is undefined.
+ if (self.symbol_resolver.contains(sym_name)) continue;
- try object.symbols.append(self.allocator, symbol);
+ const undef_sym_index = @intCast(u32, self.undefs.items.len);
+ try self.undefs.append(self.allocator, .{
+ .n_strx = try self.makeString(sym_name),
+ .n_type = macho.N_UNDF,
+ .n_sect = 0,
+ .n_desc = 0,
+ .n_value = 0,
+ });
+ try self.symbol_resolver.putNoClobber(self.allocator, try self.allocator.dupe(u8, sym_name), .{
+ .where = .undef,
+ .where_index = undef_sym_index,
+ .file = object_id,
+ });
+ }
}
}
fn resolveSymbols(self: *Zld) !void {
// TODO mimicking insertion of null symbol from incremental linker.
// This will need to moved.
- const null_sym = try self.allocator.create(Symbol);
- null_sym.* = .{ .strx = 0, .payload = .{ .undef = .{} } };
- try self.locals.append(self.allocator, null_sym);
+ try self.locals.append(self.allocator, .{
+ .n_strx = 0,
+ .n_type = macho.N_UNDF,
+ .n_sect = 0,
+ .n_desc = 0,
+ .n_value = 0,
+ });
+ try self.strtab.append(self.allocator, 0);
// First pass, resolve symbols in provided objects.
- for (self.objects.items) |object| {
- try self.resolveSymbolsInObject(object);
+ for (self.objects.items) |_, object_id| {
+ try self.resolveSymbolsInObject(@intCast(u16, object_id));
}
// Second pass, resolve symbols in static libraries.
- var sym_it = self.globals.iterator();
- while (sym_it.next()) |entry| {
- const sym_name = entry.key_ptr.*;
- const symbol = entry.value_ptr.*;
- if (symbol.payload != .undef) continue;
+ loop: for (self.undefs.items) |sym| {
+ if (symbolIsNull(sym)) continue;
+
+ const sym_name = self.getString(sym.n_strx);
for (self.archives.items) |archive| {
// Check if the entry exists in a static archive.
@@ -1462,167 +1655,184 @@ fn resolveSymbols(self: *Zld) !void {
assert(offsets.items.len > 0);
const object = try archive.parseObject(offsets.items[0]);
+ const object_id = @intCast(u16, self.objects.items.len);
try self.objects.append(self.allocator, object);
- try self.resolveSymbolsInObject(object);
+ try self.resolveSymbolsInObject(object_id);
- sym_it = self.globals.iterator();
- break;
+ continue :loop;
}
}
- // Put any globally defined regular symbol as local.
// Convert any tentative definition into a regular symbol and allocate
// text blocks for each tentative defintion.
- for (self.globals.values()) |symbol| {
- switch (symbol.payload) {
- .regular => |*reg| {
- reg.local_sym_index = @intCast(u32, self.locals.items.len);
- try self.locals.append(self.allocator, symbol);
- },
- .tentative => |tent| {
- const match: MatchingSection = blk: {
- if (self.common_section_index == null) {
- const data_seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
- self.common_section_index = @intCast(u16, data_seg.sections.items.len);
- try data_seg.addSection(self.allocator, "__common", .{
- .flags = macho.S_ZEROFILL,
- });
- }
- break :blk .{
- .seg = self.data_segment_cmd_index.?,
- .sect = self.common_section_index.?,
- };
- };
+ for (self.tentatives.items) |sym| {
+ const sym_name = self.getString(sym.n_strx);
+ const match: MatchingSection = blk: {
+ if (self.common_section_index == null) {
+ const data_seg = &self.load_commands.items[self.data_segment_cmd_index.?].Segment;
+ self.common_section_index = @intCast(u16, data_seg.sections.items.len);
+ try data_seg.addSection(self.allocator, "__common", .{
+ .flags = macho.S_ZEROFILL,
+ });
+ }
+ break :blk .{
+ .seg = self.data_segment_cmd_index.?,
+ .sect = self.common_section_index.?,
+ };
+ };
- const size = tent.size;
- const code = try self.allocator.alloc(u8, size);
- mem.set(u8, code, 0);
- const alignment = tent.alignment;
- const local_sym_index = @intCast(u32, self.locals.items.len);
-
- symbol.payload = .{
- .regular = .{
- .linkage = .global,
- .segment_id = self.data_segment_cmd_index.?,
- .section_id = self.common_section_index.?,
- .local_sym_index = local_sym_index,
- },
- };
- try self.locals.append(self.allocator, symbol);
-
- const block = try self.allocator.create(TextBlock);
- errdefer self.allocator.destroy(block);
-
- block.* = TextBlock.init(self.allocator);
- block.local_sym_index = local_sym_index;
- block.code = code;
- block.size = size;
- block.alignment = alignment;
-
- // Update target section's metadata
- // TODO should we update segment's size here too?
- // How does it tie with incremental space allocs?
- const tseg = &self.load_commands.items[match.seg].Segment;
- const tsect = &tseg.sections.items[match.sect];
- const new_alignment = math.max(tsect.@"align", block.alignment);
- const new_alignment_pow_2 = try math.powi(u32, 2, new_alignment);
- const new_size = mem.alignForwardGeneric(u64, tsect.size, new_alignment_pow_2) + block.size;
- tsect.size = new_size;
- tsect.@"align" = new_alignment;
-
- if (self.blocks.getPtr(match)) |last| {
- last.*.next = block;
- block.prev = last.*;
- last.* = block;
- } else {
- try self.blocks.putNoClobber(self.allocator, match, block);
- }
- },
- else => {},
+ const size = sym.n_value;
+ const code = try self.allocator.alloc(u8, size);
+ mem.set(u8, code, 0);
+ const alignment = (sym.n_desc >> 8) & 0x0f;
+
+ const resolv = self.symbol_resolver.getPtr(sym_name) orelse unreachable;
+ const local_sym_index = @intCast(u32, self.locals.items.len);
+ var nlist = macho.nlist_64{
+ .n_strx = sym.n_strx,
+ .n_type = macho.N_SECT,
+ .n_sect = self.sectionId(match),
+ .n_desc = 0,
+ .n_value = 0,
+ };
+ try self.locals.append(self.allocator, nlist);
+ const global_sym_index = @intCast(u32, self.globals.items.len);
+ nlist.n_type |= macho.N_EXT;
+ try self.globals.append(self.allocator, nlist);
+ resolv.* = .{
+ .where = .global,
+ .where_index = global_sym_index,
+ .local_sym_index = local_sym_index,
+ };
+
+ const block = try self.allocator.create(TextBlock);
+ errdefer self.allocator.destroy(block);
+
+ block.* = TextBlock.init(self.allocator);
+ block.local_sym_index = local_sym_index;
+ block.code = code;
+ block.size = size;
+ block.alignment = alignment;
+
+ // Update target section's metadata
+ // TODO should we update segment's size here too?
+ // How does it tie with incremental space allocs?
+ const tseg = &self.load_commands.items[match.seg].Segment;
+ const tsect = &tseg.sections.items[match.sect];
+ const new_alignment = math.max(tsect.@"align", block.alignment);
+ const new_alignment_pow_2 = try math.powi(u32, 2, new_alignment);
+ const new_size = mem.alignForwardGeneric(u64, tsect.size, new_alignment_pow_2) + block.size;
+ tsect.size = new_size;
+ tsect.@"align" = new_alignment;
+
+ if (self.blocks.getPtr(match)) |last| {
+ last.*.next = block;
+ block.prev = last.*;
+ last.* = block;
+ } else {
+ try self.blocks.putNoClobber(self.allocator, match, block);
}
}
// Third pass, resolve symbols in dynamic libraries.
{
// Put dyld_stub_binder as an undefined special symbol.
- const symbol = try self.allocator.create(Symbol);
- symbol.* = .{
- .strx = try self.makeString("dyld_stub_binder"),
- .payload = .{ .undef = .{} },
- };
- const index = @intCast(u32, self.got_entries.items.len);
- symbol.got_index = index;
- try self.got_entries.append(self.allocator, symbol);
- const alloc_name = try self.allocator.dupe(u8, "dyld_stub_binder");
- try self.globals.putNoClobber(self.allocator, alloc_name, symbol);
+ const undef_sym_index = @intCast(u32, self.undefs.items.len);
+ try self.undefs.append(self.allocator, .{
+ .n_strx = try self.makeString("dyld_stub_binder"),
+ .n_type = macho.N_UNDF,
+ .n_sect = 0,
+ .n_desc = 0,
+ .n_value = 0,
+ });
+ try self.symbol_resolver.putNoClobber(self.allocator, try self.allocator.dupe(u8, "dyld_stub_binder"), .{
+ .where = .undef,
+ .where_index = undef_sym_index,
+ });
}
var referenced = std.AutoHashMap(*Dylib, void).init(self.allocator);
defer referenced.deinit();
- loop: for (self.globals.keys()) |sym_name| {
- const symbol = self.globals.get(sym_name).?;
- if (symbol.payload != .undef) continue;
+ loop: for (self.undefs.items) |sym| {
+ if (symbolIsNull(sym)) continue;
+ const sym_name = self.getString(sym.n_strx);
for (self.dylibs.items) |dylib| {
if (!dylib.symbols.contains(sym_name)) continue;
- try referenced.put(dylib, {});
- const index = @intCast(u32, self.imports.items.len);
- symbol.payload = .{
- .proxy = .{
- .file = dylib,
- .local_sym_index = index,
- },
+ if (!referenced.contains(dylib)) {
+ // Add LC_LOAD_DYLIB load command for each referenced dylib/stub.
+ dylib.ordinal = self.next_dylib_ordinal;
+ const dylib_id = dylib.id orelse unreachable;
+ var dylib_cmd = try createLoadDylibCommand(
+ self.allocator,
+ dylib_id.name,
+ dylib_id.timestamp,
+ dylib_id.current_version,
+ dylib_id.compatibility_version,
+ );
+ errdefer dylib_cmd.deinit(self.allocator);
+ try self.load_commands.append(self.allocator, .{ .Dylib = dylib_cmd });
+ self.next_dylib_ordinal += 1;
+ try referenced.putNoClobber(dylib, {});
+ }
+
+ const resolv = self.symbol_resolver.getPtr(sym_name) orelse unreachable;
+ const undef = &self.undefs.items[resolv.where_index];
+ const import_sym_index = @intCast(u32, self.imports.items.len);
+ try self.imports.append(self.allocator, .{
+ .n_strx = undef.n_strx,
+ .n_type = macho.N_UNDF | macho.N_EXT,
+ .n_sect = 0,
+ .n_desc = (dylib.ordinal.? * macho.N_SYMBOL_RESOLVER) | macho.REFERENCE_FLAG_UNDEFINED_NON_LAZY,
+ .n_value = 0,
+ });
+ resolv.* = .{
+ .where = .import,
+ .where_index = import_sym_index,
};
- try self.imports.append(self.allocator, symbol);
+ undef.* = .{
+ .n_strx = 0,
+ .n_type = macho.N_UNDF,
+ .n_sect = 0,
+ .n_desc = 0,
+ .n_value = 0,
+ };
+
continue :loop;
}
}
- // Add LC_LOAD_DYLIB load command for each referenced dylib/stub.
- var it = referenced.iterator();
- while (it.next()) |entry| {
- const dylib = entry.key_ptr.*;
- dylib.ordinal = self.next_dylib_ordinal;
- const dylib_id = dylib.id orelse unreachable;
- var dylib_cmd = try createLoadDylibCommand(
- self.allocator,
- dylib_id.name,
- dylib_id.timestamp,
- dylib_id.current_version,
- dylib_id.compatibility_version,
- );
- errdefer dylib_cmd.deinit(self.allocator);
- try self.load_commands.append(self.allocator, .{ .Dylib = dylib_cmd });
- self.next_dylib_ordinal += 1;
- }
-
// Fourth pass, handle synthetic symbols and flag any undefined references.
- if (self.globals.get("___dso_handle")) |symbol| {
- if (symbol.payload == .undef) {
- const seg = self.load_commands.items[self.text_segment_cmd_index.?].Segment;
- symbol.payload = .{
- .regular = .{
- .linkage = .translation_unit,
- .address = seg.inner.vmaddr,
- .weak_ref = true,
- .local_sym_index = @intCast(u32, self.locals.items.len),
- },
- };
- try self.locals.append(self.allocator, symbol);
- }
+ if (self.symbol_resolver.getPtr("___dso_handle")) |resolv| blk: {
+ if (resolv.where != .undef) break :blk;
+
+ const seg = self.load_commands.items[self.text_segment_cmd_index.?].Segment;
+ const undef = &self.undefs.items[resolv.where_index];
+ const global_sym_index = @intCast(u32, self.globals.items.len);
+ try self.globals.append(self.allocator, .{
+ .n_strx = undef.n_strx,
+ .n_type = macho.N_PEXT | macho.N_EXT | macho.N_SECT,
+ .n_sect = 0,
+ .n_desc = macho.N_WEAK_DEF,
+ .n_value = seg.inner.vmaddr,
+ });
+ resolv.* = .{
+ .where = .global,
+ .where_index = global_sym_index,
+ };
}
var has_undefined = false;
- for (self.globals.keys()) |sym_name| {
- const symbol = self.globals.get(sym_name).?;
- if (symbol.payload != .undef) continue;
+ for (self.undefs.items) |sym| {
+ if (symbolIsNull(sym)) continue;
+
+ const sym_name = self.getString(sym.n_strx);
+ const resolv = self.symbol_resolver.get(sym_name) orelse unreachable;
log.err("undefined reference to symbol '{s}'", .{sym_name});
- if (symbol.payload.undef.file) |file| {
- log.err(" | referenced in {s}", .{file.name.?});
- }
+ log.err(" first referenced in '{s}'", .{self.objects.items[resolv.file].name.?});
has_undefined = true;
}
@@ -2776,3 +2986,82 @@ pub fn getString(self: *Zld, off: u32) []const u8 {
assert(off < self.strtab.items.len);
return mem.spanZ(@ptrCast([*:0]const u8, self.strtab.items.ptr + off));
}
+
+fn localSymIndex(self: Zld, object_id: u16, orig_id: u32) ?u32 {
+ const mapping = self.object_mapping.get(object_id) orelse return null;
+ const local_sym_index = mapping[orig_id];
+ if (local_sym_index == 0) {
+ return null;
+ }
+ return local_sym_index;
+}
+
+pub fn symbolIsStab(sym: macho.nlist_64) bool {
+ return (macho.N_STAB & sym.n_type) != 0;
+}
+
+pub fn symbolIsPext(sym: macho.nlist_64) bool {
+ return (macho.N_PEXT & sym.n_type) != 0;
+}
+
+pub fn symbolIsExt(sym: macho.nlist_64) bool {
+ return (macho.N_EXT & sym.n_type) != 0;
+}
+
+pub fn symbolIsSect(sym: macho.nlist_64) bool {
+ const type_ = macho.N_TYPE & sym.n_type;
+ return type_ == macho.N_SECT;
+}
+
+pub fn symbolIsUndf(sym: macho.nlist_64) bool {
+ const type_ = macho.N_TYPE & sym.n_type;
+ return type_ == macho.N_UNDF;
+}
+
+pub fn symbolIsIndr(sym: macho.nlist_64) bool {
+ const type_ = macho.N_TYPE & sym.n_type;
+ return type_ == macho.N_INDR;
+}
+
+pub fn symbolIsAbs(sym: macho.nlist_64) bool {
+ const type_ = macho.N_TYPE & sym.n_type;
+ return type_ == macho.N_ABS;
+}
+
+pub fn symbolIsWeakDef(sym: macho.nlist_64) bool {
+ return (sym.n_desc & macho.N_WEAK_DEF) != 0;
+}
+
+pub fn symbolIsWeakRef(sym: macho.nlist_64) bool {
+ return (sym.n_desc & macho.N_WEAK_REF) != 0;
+}
+
+pub fn symbolIsTentative(sym: macho.nlist_64) bool {
+ if (!symbolIsUndf(sym)) return false;
+ return sym.n_value != 0;
+}
+
+pub fn symbolIsNull(sym: macho.nlist_64) bool {
+ return sym.n_value == 0 and sym.n_desc == 0 and sym.n_type == 0 and sym.n_strx == 0 and sym.n_sect == 0;
+}
+
+pub fn symbolIsTemp(self: Zld, sym: macho.nlist_64) bool {
+ if (!symbolIsSect(sym)) return false;
+ if (symbolIsExt(sym)) return false;
+ const sym_name = self.getString(sym.n_strx);
+ return mem.startsWith(u8, sym_name, "l") or mem.startsWith(u8, sym_name, "L");
+}
+
+pub fn sectionId(self: Zld, match: MatchingSection) u8 {
+ // TODO there might be a more generic way of doing this.
+ var section: u8 = 0;
+ for (self.load_commands.items) |cmd, cmd_id| {
+ if (cmd != .Segment) break;
+ if (cmd_id == match.seg) {
+ section += @intCast(u8, match.sect) + 1;
+ break;
+ }
+ section += @intCast(u8, cmd.Segment.sections.items.len);
+ }
+ return section;
+}