diff options
Diffstat (limited to 'src/link')
| -rw-r--r-- | src/link/MachO.zig | 212 |
1 files changed, 188 insertions, 24 deletions
diff --git a/src/link/MachO.zig b/src/link/MachO.zig index 816e4e0023..0ee0879290 100644 --- a/src/link/MachO.zig +++ b/src/link/MachO.zig @@ -38,6 +38,7 @@ const Module = @import("../Module.zig"); const StringIndexAdapter = std.hash_map.StringIndexAdapter; const StringIndexContext = std.hash_map.StringIndexContext; const Trie = @import("MachO/Trie.zig"); +const Type = @import("../type.zig").Type; pub const TextBlock = Atom; @@ -220,7 +221,7 @@ managed_atoms: std.ArrayListUnmanaged(*Atom) = .{}, /// We store them here so that we can properly dispose of any allocated /// memory within the atom in the incremental linker. /// TODO consolidate this. -decls: std.AutoArrayHashMapUnmanaged(*Module.Decl, void) = .{}, +decls: std.AutoArrayHashMapUnmanaged(*Module.Decl, ?MatchingSection) = .{}, /// Currently active Module.Decl. /// TODO this might not be necessary if we figure out how to pass Module.Decl instance @@ -3450,7 +3451,7 @@ pub fn allocateDeclIndexes(self: *MachO, decl: *Module.Decl) !void { if (decl.link.macho.local_sym_index != 0) return; try self.locals.ensureUnusedCapacity(self.base.allocator, 1); - try self.decls.putNoClobber(self.base.allocator, decl, {}); + try self.decls.putNoClobber(self.base.allocator, decl, null); if (self.locals_free_list.popOrNull()) |i| { log.debug("reusing symbol index {d} for {s}", .{ i, decl.name }); @@ -3656,19 +3657,169 @@ pub fn updateDecl(self: *MachO, module: *Module, decl: *Module.Decl) !void { try self.updateDeclExports(module, decl, decl_exports); } +fn isElemTyPointer(ty: Type) bool { + switch (ty.zigTypeTag()) { + .Fn => return false, + .Pointer => return true, + .Array => { + const elem_ty = ty.elemType(); + return isElemTyPointer(elem_ty); + }, + .Struct, .Union => { + const len = ty.structFieldCount(); + var i: usize = 0; + while (i < len) : (i += 1) { + const field_ty = ty.structFieldType(i); + if (isElemTyPointer(field_ty)) return true; + } + return false; + }, + else => return false, + } +} + +fn getMatchingSectionDecl(self: *MachO, decl: *Module.Decl) !MatchingSection { + const code = decl.link.macho.code.items; + const alignment = decl.ty.abiAlignment(self.base.options.target); + const align_log_2 = math.log2(alignment); + const ty = decl.ty; + const zig_ty = ty.zigTypeTag(); + const val = decl.val; + const mode = self.base.options.optimize_mode; + const match: MatchingSection = blk: { + // TODO finish and audit this function + if (val.isUndefDeep()) { + if (mode == .ReleaseFast or mode == .ReleaseSmall) { + break :blk MatchingSection{ + .seg = self.data_segment_cmd_index.?, + .sect = self.bss_section_index.?, + }; + } + break :blk (try self.getMatchingSection(.{ + .segname = makeStaticString("__DATA"), + .sectname = makeStaticString("__data"), + .size = code.len, + .@"align" = align_log_2, + })).?; + } + + switch (zig_ty) { + .Fn => { + break :blk MatchingSection{ + .seg = self.text_segment_cmd_index.?, + .sect = self.text_section_index.?, + }; + }, + .Array => switch (val.tag()) { + .bytes => { + switch (ty.tag()) { + .array_u8_sentinel_0, + .const_slice_u8_sentinel_0, + .manyptr_const_u8_sentinel_0, + => { + break :blk (try self.getMatchingSection(.{ + .segname = makeStaticString("__TEXT"), + .sectname = makeStaticString("__cstring"), + .flags = macho.S_CSTRING_LITERALS, + .size = code.len, + .@"align" = align_log_2, + })).?; + }, + else => { + break :blk (try self.getMatchingSection(.{ + .segname = makeStaticString("__TEXT"), + .sectname = makeStaticString("__const"), + .size = code.len, + .@"align" = align_log_2, + })).?; + }, + } + }, + .array => { + if (isElemTyPointer(ty)) { + break :blk (try self.getMatchingSection(.{ + .segname = makeStaticString("__DATA_CONST"), + .sectname = makeStaticString("__const"), + .size = code.len, + .@"align" = 3, // TODO I think this should not be needed + })).?; + } else { + break :blk (try self.getMatchingSection(.{ + .segname = makeStaticString("__TEXT"), + .sectname = makeStaticString("__const"), + .size = code.len, + .@"align" = align_log_2, + })).?; + } + }, + else => { + break :blk (try self.getMatchingSection(.{ + .segname = makeStaticString("__TEXT"), + .sectname = makeStaticString("__const"), + .size = code.len, + .@"align" = align_log_2, + })).?; + }, + }, + .Pointer => { + if (val.castTag(.variable)) |_| { + break :blk MatchingSection{ + .seg = self.data_segment_cmd_index.?, + .sect = self.data_section_index.?, + }; + } else { + break :blk (try self.getMatchingSection(.{ + .segname = makeStaticString("__DATA_CONST"), + .sectname = makeStaticString("__const"), + .size = code.len, + .@"align" = align_log_2, + })).?; + } + }, + else => { + if (val.castTag(.variable)) |_| { + break :blk MatchingSection{ + .seg = self.data_segment_cmd_index.?, + .sect = self.data_section_index.?, + }; + } else { + break :blk (try self.getMatchingSection(.{ + .segname = makeStaticString("__TEXT"), + .sectname = makeStaticString("__const"), + .size = code.len, + .@"align" = align_log_2, + })).?; + } + }, + } + }; + const seg = self.load_commands.items[match.seg].segment; + const sect = seg.sections.items[match.sect]; + log.debug(" allocating atom in '{s},{s}' ({d},{d})", .{ + sect.segName(), + sect.sectName(), + match.seg, + match.sect, + }); + return match; +} + fn placeDecl(self: *MachO, decl: *Module.Decl, code_len: usize) !*macho.nlist_64 { const required_alignment = decl.ty.abiAlignment(self.base.options.target); assert(decl.link.macho.local_sym_index != 0); // Caller forgot to call allocateDeclIndexes() const symbol = &self.locals.items[decl.link.macho.local_sym_index]; + const decl_ptr = self.decls.getPtr(decl).?; + if (decl_ptr.* == null) { + decl_ptr.* = try self.getMatchingSectionDecl(decl); + } + const match = decl_ptr.*.?; + if (decl.link.macho.size != 0) { const capacity = decl.link.macho.capacity(self.*); const need_realloc = code_len > capacity or !mem.isAlignedGeneric(u64, symbol.n_value, required_alignment); if (need_realloc) { - const vaddr = try self.growAtom(&decl.link.macho, code_len, required_alignment, .{ - .seg = self.text_segment_cmd_index.?, - .sect = self.text_section_index.?, - }); + const vaddr = try self.growAtom(&decl.link.macho, code_len, required_alignment, match); log.debug("growing {s} and moving from 0x{x} to 0x{x}", .{ decl.name, symbol.n_value, vaddr }); @@ -3690,10 +3841,7 @@ fn placeDecl(self: *MachO, decl: *Module.Decl, code_len: usize) !*macho.nlist_64 symbol.n_value = vaddr; } else if (code_len < decl.link.macho.size) { - self.shrinkAtom(&decl.link.macho, code_len, .{ - .seg = self.text_segment_cmd_index.?, - .sect = self.text_section_index.?, - }); + self.shrinkAtom(&decl.link.macho, code_len, match); } decl.link.macho.size = code_len; decl.link.macho.dirty = true; @@ -3714,22 +3862,16 @@ fn placeDecl(self: *MachO, decl: *Module.Decl, code_len: usize) !*macho.nlist_64 defer self.base.allocator.free(decl_name); const name_str_index = try self.makeString(decl_name); - const addr = try self.allocateAtom(&decl.link.macho, code_len, required_alignment, .{ - .seg = self.text_segment_cmd_index.?, - .sect = self.text_section_index.?, - }); + const addr = try self.allocateAtom(&decl.link.macho, code_len, required_alignment, match); log.debug("allocated atom for {s} at 0x{x}", .{ decl_name, addr }); - errdefer self.freeAtom(&decl.link.macho, .{ - .seg = self.text_segment_cmd_index.?, - .sect = self.text_section_index.?, - }); + errdefer self.freeAtom(&decl.link.macho, match); symbol.* = .{ .n_strx = name_str_index, .n_type = macho.N_SECT, - .n_sect = @intCast(u8, self.text_section_index.?) + 1, + .n_sect = @intCast(u8, self.section_ordinals.getIndex(match).?) + 1, .n_desc = 0, .n_value = addr, }; @@ -3912,12 +4054,11 @@ pub fn freeDecl(self: *MachO, decl: *Module.Decl) void { if (self.llvm_object) |llvm_object| return llvm_object.freeDecl(decl); } log.debug("freeDecl {*}", .{decl}); - _ = self.decls.swapRemove(decl); + const kv = self.decls.fetchSwapRemove(decl); + if (kv.?.value) |match| { + self.freeAtom(&decl.link.macho, match); + } // Appending to free lists is allowed to fail because the free lists are heuristics based anyway. - self.freeAtom(&decl.link.macho, .{ - .seg = self.text_segment_cmd_index.?, - .sect = self.text_section_index.?, - }); if (decl.link.macho.local_sym_index != 0) { self.locals_free_list.append(self.base.allocator, decl.link.macho.local_sym_index) catch {}; @@ -3958,6 +4099,29 @@ pub fn getDeclVAddr(self: *MachO, decl: *const Module.Decl) u64 { return self.locals.items[decl.link.macho.local_sym_index].n_value; } +pub fn getDeclVAddrWithReloc(self: *MachO, decl: *const Module.Decl, offset: u64) !u64 { + assert(decl.link.macho.local_sym_index != 0); + assert(self.active_decl != null); + + const atom = &self.active_decl.?.link.macho; + try atom.relocs.append(self.base.allocator, .{ + .offset = @intCast(u32, offset), + .target = .{ .local = decl.link.macho.local_sym_index }, + .addend = 0, + .subtractor = null, + .pcrel = false, + .length = 3, + .@"type" = switch (self.base.options.target.cpu.arch) { + .aarch64 => @enumToInt(macho.reloc_type_arm64.ARM64_RELOC_UNSIGNED), + .x86_64 => @enumToInt(macho.reloc_type_x86_64.X86_64_RELOC_UNSIGNED), + else => unreachable, + }, + }); + try atom.rebases.append(self.base.allocator, offset); + + return 0; +} + fn populateMissingMetadata(self: *MachO) !void { const cpu_arch = self.base.options.target.cpu.arch; |