diff --git a/src/arch/wasm/CodeGen.zig b/src/arch/wasm/CodeGen.zig index 8eb767fbb5..3282d1304a 100644 --- a/src/arch/wasm/CodeGen.zig +++ b/src/arch/wasm/CodeGen.zig @@ -1944,6 +1944,7 @@ fn genInst(func: *CodeGen, inst: Air.Inst.Index) InnerError!void { .memcpy => func.airMemcpy(inst), .ret_addr => func.airRetAddr(inst), + .tag_name => func.airTagName(inst), .mul_sat, .mod, @@ -1962,7 +1963,6 @@ fn genInst(func: *CodeGen, inst: Air.Inst.Index) InnerError!void { .atomic_store_release, .atomic_store_seq_cst, .atomic_rmw, - .tag_name, .err_return_trace, .set_err_return_trace, .save_err_return_trace_index, @@ -6396,3 +6396,184 @@ fn callIntrinsic( return WValue{ .stack = {} }; } } + +fn airTagName(func: *CodeGen, inst: Air.Inst.Index) InnerError!void { + const un_op = func.air.instructions.items(.data)[inst].un_op; + if (func.liveness.isUnused(inst)) return func.finishAir(inst, .none, &.{un_op}); + // const operand = try func.resolveInst(un_op); + const enum_ty = func.air.typeOf(un_op); + + _ = try func.getTagNameFunction(enum_ty); + + func.finishAir(inst, .none, &.{un_op}); +} + +fn getTagNameFunction(func: *CodeGen, enum_ty: Type) InnerError!u32 { + const enum_decl_index = enum_ty.getOwnerDecl(); + const module = func.bin_file.base.options.module.?; + + // check if we already generated code for this. + if (func.bin_file.decls.get(enum_decl_index)) |decl_atom_index| { + std.debug.print("Found atom index for Enum decl! {d}\n", .{decl_atom_index}); + const atom = func.bin_file.getAtom(decl_atom_index); + return atom.getSymbolIndex().?; + } + + // Create an atom in which we will store all tag names. + const func_atom_index = try func.bin_file.getOrCreateAtomForDecl(enum_decl_index); + const func_atom = func.bin_file.getAtomPtr(func_atom_index); + std.debug.print("Generated a new atom! {d}\n", .{func_atom_index}); + + var arena_allocator = std.heap.ArenaAllocator.init(func.gpa); + defer arena_allocator.deinit(); + const arena = arena_allocator.allocator(); + + const fqn = try module.declPtr(enum_decl_index).getFullyQualifiedName(module); + defer module.gpa.free(fqn); + const func_name = try std.fmt.allocPrintZ(arena, "__zig_tag_name_{s}", .{fqn}); + + if (func.bin_file.findGlobalSymbol(func_name)) |loc| { + return loc.index; + } + + const slice_ty = Type.initTag(.const_slice_u8_sentinel_0); + var int_tag_type_buffer: Type.Payload.Bits = undefined; + const int_tag_ty = enum_ty.intTagType(&int_tag_type_buffer); + + if (int_tag_ty.bitSize(func.target) > 64) { + return func.fail("TODO: Implement @tagName for enums with tag size larger than 64 bits", .{}); + } + + var func_type = try genFunctype(func.gpa, .Unspecified, &.{int_tag_ty}, slice_ty, func.target); + defer func_type.deinit(func.gpa); + try func.bin_file.storeDeclType(enum_decl_index, func_type); + + var body_list = std.ArrayList(u8).init(arena); + var writer = body_list.writer(); + + // The locals of the function body (always 2) + try leb.writeULEB128(writer, @as(u32, 2)); + try leb.writeULEB128(writer, @as(u32, 1)); + try writer.writeByte(func.genValtype(slice_ty, func.target)); + try leb.writeULEB128(writer, @as(u32, 1)); + try writer.writeByte(func.genValtype(int_tag_ty, func.target)); + + // outer block + try writer.writeByte(std.wasm.opcode(.block)); + + // TODO: Make switch implementation generic so we can use a jump table for this when the tags are not sparse. + // generate an if-else chain for each tag value as well as constant. + for (enum_ty.enumFields().keys(), 0..) |tag_name, field_index| { + // for each tag name, create an atom to store its name into, + // and then get a pointer to its value. + const tag_atom_index = try func.bin_file.createAtom(); + const tag_atom = func.bin_file.getAtomPtr(tag_atom_index); + tag_atom.alignment = 1; + try func.bin_file.parseAtom(tag_atom_index, .read_only); + try tag_atom.code.appendSlice(func.gpa, tag_name); + + // block for this if case + try writer.writeByte(std.wasm.opcode(.block)); + + // get actual tag value (stored in 2nd parameter); + try writer.writeByte(std.wasm.opcode(.local_get)); + try leb.writeULEB128(writer, @as(u32, 1)); + + const tag_value = int: { + var tag_val_payload: Value.Payload.U32 = .{ + .base = .{ .tag = .enum_field_index }, + .data = @intCast(u32, field_index), + }; + break :int try func.lowerConstant(Value.initPayload(&tag_val_payload.base), enum_ty); + }; + + switch (tag_value) { + .imm32 => |value| { + try writer.writeByte(std.wasm.opcode(.i32_const)); + try leb.writeULEB128(writer, value); + try writer.writeByte(std.wasm.opcode(.i32_neq)); + }, + .imm64 => |value| { + try writer.writeByte(std.wasm.opcode(.i64_const)); + try leb.writeULEB128(writer, value); + try writer.writeByte(std.wasm.opcode(.i64_neq)); + }, + else => unreachable, + } + // if they're not equal, break out of current branch + try writer.writeByte(std.wasm.opcode(.br_if)); + + // store the address of the tagname in the pointer field of the slice + try writer.writeByte(std.wasm.opcode(.local_get)); + try leb.writeULEB128(writer, @as(u32, 0)); + + const is_wasm32 = func.arch() == .wasm32; + // get address of tagname and emit a relocation to it + { + if (is_wasm32) { + try writer.writeByte(std.wasm.opcode(.i32_const)); + var buf: [5]u8 = undefined; + leb.writeUnsignedFixed(5, &buf, mem.pointer); + try writer.writeAll(&buf); + } else { + try writer.writeByte(std.wasm.opcode(.i64_const)); + var buf: [10]u8 = undefined; + leb.writeUnsignedFixed(10, &buf, mem.pointer); + try writer.writeAll(&buf); + } + try func_atom.relocs.append(func.gpa, .{ + .relocation_type = if (is_wasm32) .R_WASM_MEMORY_ADDR_LEB else .R_WASM_MEMORY_ADDR_LEB64, + .offset = @intCast(u32, body_list.items.len), + .index = tag_atom.getSymbolIndex().?, + }); + } + + // call the actual store instructions + if (is_wasm32) { + // store pointer + try writer.writeByte(std.wasm.opcode(.i32_store)); + try leb.writeULEB128(writer, @as(u32, 4)); + try leb.writeULEB128(writer, @as(u32, 0)); + + // store length + try writer.writeByte(std.wasm.opcode(.local_get)); + try leb.writeULEB128(writer, @as(u32, 0)); + try writer.writeByte(std.wasm.opcode(.i32_const)); + try leb.writeULEB128(writer, @intCast(u32, tag_name.len)); + try writer.writeByte(std.wasm.opcode(.i32_store)); + try leb.writeULEB128(writer, @as(u32, 4)); + try leb.writeULEB128(writer, @as(u32, 4)); + } else { + // store pointer + try writer.writeByte(std.wasm.opcode(.i64_store)); + try leb.writeULEB128(writer, @as(u32, 8)); + try leb.writeULEB128(writer, @as(u32, 0)); + + // store length + try writer.writeByte(std.wasm.opcode(.local_get)); + try leb.writeULEB128(writer, @as(u32, 0)); + try writer.writeByte(std.wasm.opcode(.i64_const)); + try leb.writeULEB128(writer, @intCast(u64, tag_name.len)); + try writer.writeByte(std.wasm.opcode(.i64_store)); + try leb.writeULEB128(writer, @as(u32, 8)); + try leb.writeULEB128(writer, @as(u32, 8)); + } + + // break outside blocks + try writer.writeByte(std.wasm.opcode(.br)); + try leb.writeULEB128(writer, @as(u32, 1)); + + // end the block for this case + try writer.writeByte(std.wasm.opcode(.end)); + } + + try writer.writeByte(std.wasm.opcode(.@"unreachable")); // tag value does not have a name + // finish outer block + try writer.writeByte(std.wasm.opcode(.end)); + // finish function body + try writer.writeByte(std.wasm.opcode(.end)); + + try func_atom.code.appendSlice(func.gpa, body_list.items); + + return func_atom.sym_index; +} diff --git a/src/link/Wasm.zig b/src/link/Wasm.zig index b1fc25bf26..639b7f0776 100644 --- a/src/link/Wasm.zig +++ b/src/link/Wasm.zig @@ -577,7 +577,7 @@ pub fn getOrCreateAtomForDecl(wasm: *Wasm, decl_index: Module.Decl.Index) !Atom. } /// Creates a new empty `Atom` and returns its `Atom.Index` -fn createAtom(wasm: *Wasm) !Atom.Index { +pub fn createAtom(wasm: *Wasm) !Atom.Index { const index = @intCast(Atom.Index, wasm.managed_atoms.items.len); const atom = try wasm.managed_atoms.addOne(wasm.base.allocator); atom.* = Atom.empty; @@ -1208,7 +1208,7 @@ fn resolveLazySymbols(wasm: *Wasm) !void { // Tries to find a global symbol by its name. Returns null when not found, /// and its location when it is found. -fn findGlobalSymbol(wasm: *Wasm, name: []const u8) ?SymbolLoc { +pub fn findGlobalSymbol(wasm: *Wasm, name: []const u8) ?SymbolLoc { const offset = wasm.string_table.getOffset(name) orelse return null; return wasm.globals.get(offset); }