Commit c66b48194f

Andrew Kelley <andrew@ziglang.org>
2021-04-02 04:27:17
stage2: AstGen and ZIR printing for struct decls
1 parent 09000c3
src/AstGen.zig
@@ -719,25 +719,25 @@ pub fn expr(gz: *GenZir, scope: *Scope, rl: ResultLoc, node: ast.Node.Index) Inn
 
         .container_decl,
         .container_decl_trailing,
-        => return containerDecl(gz, scope, rl, tree.containerDecl(node)),
+        => return containerDecl(gz, scope, rl, node, tree.containerDecl(node)),
         .container_decl_two, .container_decl_two_trailing => {
             var buffer: [2]ast.Node.Index = undefined;
-            return containerDecl(gz, scope, rl, tree.containerDeclTwo(&buffer, node));
+            return containerDecl(gz, scope, rl, node, tree.containerDeclTwo(&buffer, node));
         },
         .container_decl_arg,
         .container_decl_arg_trailing,
-        => return containerDecl(gz, scope, rl, tree.containerDeclArg(node)),
+        => return containerDecl(gz, scope, rl, node, tree.containerDeclArg(node)),
 
         .tagged_union,
         .tagged_union_trailing,
-        => return containerDecl(gz, scope, rl, tree.taggedUnion(node)),
+        => return containerDecl(gz, scope, rl, node, tree.taggedUnion(node)),
         .tagged_union_two, .tagged_union_two_trailing => {
             var buffer: [2]ast.Node.Index = undefined;
-            return containerDecl(gz, scope, rl, tree.taggedUnionTwo(&buffer, node));
+            return containerDecl(gz, scope, rl, node, tree.taggedUnionTwo(&buffer, node));
         },
         .tagged_union_enum_tag,
         .tagged_union_enum_tag_trailing,
-        => return containerDecl(gz, scope, rl, tree.taggedUnionEnumTag(node)),
+        => return containerDecl(gz, scope, rl, node, tree.taggedUnionEnumTag(node)),
 
         .@"break" => return breakExpr(gz, scope, node),
         .@"continue" => return continueExpr(gz, scope, node),
@@ -804,6 +804,16 @@ pub fn structInitExpr(
     const astgen = gz.astgen;
     const mod = astgen.mod;
     const gpa = mod.gpa;
+
+    if (struct_init.ast.fields.len == 0) {
+        if (struct_init.ast.type_expr == 0) {
+            return rvalue(gz, scope, rl, .empty_struct, node);
+        } else {
+            const ty_inst = try typeExpr(gz, scope, struct_init.ast.type_expr);
+            const result = try gz.addUnNode(.struct_init_empty, ty_inst, node);
+            return rvalue(gz, scope, rl, result, node);
+        }
+    }
     switch (rl) {
         .discard => return mod.failNode(scope, node, "TODO implement structInitExpr discard", .{}),
         .none => return mod.failNode(scope, node, "TODO implement structInitExpr none", .{}),
@@ -1310,6 +1320,11 @@ fn blockExprStmts(
                         .switch_capture_multi_ref,
                         .switch_capture_else,
                         .switch_capture_else_ref,
+                        .struct_init_empty,
+                        .struct_decl,
+                        .union_decl,
+                        .enum_decl,
+                        .opaque_decl,
                         => break :b false,
 
                         // ZIR instructions that are always either `noreturn` or `void`.
@@ -1754,9 +1769,115 @@ fn containerDecl(
     gz: *GenZir,
     scope: *Scope,
     rl: ResultLoc,
+    node: ast.Node.Index,
     container_decl: ast.full.ContainerDecl,
 ) InnerError!zir.Inst.Ref {
-    return gz.astgen.mod.failTok(scope, container_decl.ast.main_token, "TODO implement container decls", .{});
+    const astgen = gz.astgen;
+    const mod = astgen.mod;
+    const gpa = mod.gpa;
+    const tree = gz.tree();
+    const token_tags = tree.tokens.items(.tag);
+    const node_tags = tree.nodes.items(.tag);
+
+    // We must not create any types until Sema. Here the goal is only to generate
+    // ZIR for all the field types, alignments, and default value expressions.
+
+    const arg_inst: zir.Inst.Ref = if (container_decl.ast.arg != 0)
+        try comptimeExpr(gz, scope, .none, container_decl.ast.arg)
+    else
+        .none;
+
+    switch (token_tags[container_decl.ast.main_token]) {
+        .keyword_struct => {
+            if (container_decl.ast.members.len == 0) {
+                const result = try gz.addPlNode(.struct_decl, node, zir.Inst.StructDecl{
+                    .fields_len = 0,
+                });
+                return rvalue(gz, scope, rl, result, node);
+            }
+
+            assert(arg_inst == .none);
+            var fields_data = ArrayListUnmanaged(u32){};
+            defer fields_data.deinit(gpa);
+
+            // field_name and field_type are both mandatory
+            try fields_data.ensureCapacity(gpa, container_decl.ast.members.len * 2);
+
+            // We only need this if there are greater than 16 fields.
+            var bit_bag = ArrayListUnmanaged(u32){};
+            defer bit_bag.deinit(gpa);
+
+            var cur_bit_bag: u32 = 0;
+            var member_index: usize = 0;
+            while (true) {
+                const member_node = container_decl.ast.members[member_index];
+                const member = switch (node_tags[member_node]) {
+                    .container_field_init => tree.containerFieldInit(member_node),
+                    .container_field_align => tree.containerFieldAlign(member_node),
+                    .container_field => tree.containerField(member_node),
+                    else => unreachable,
+                };
+                if (member.comptime_token) |comptime_token| {
+                    return mod.failTok(scope, comptime_token, "TODO implement comptime struct fields", .{});
+                }
+                try fields_data.ensureCapacity(gpa, fields_data.items.len + 4);
+
+                const field_name = try gz.identAsString(member.ast.name_token);
+                fields_data.appendAssumeCapacity(field_name);
+
+                const field_type = try typeExpr(gz, scope, member.ast.type_expr);
+                fields_data.appendAssumeCapacity(@enumToInt(field_type));
+
+                const have_align = member.ast.align_expr != 0;
+                const have_value = member.ast.value_expr != 0;
+                cur_bit_bag = (cur_bit_bag >> 2) |
+                    (@as(u32, @boolToInt(have_align)) << 30) |
+                    (@as(u32, @boolToInt(have_value)) << 31);
+
+                if (have_align) {
+                    const align_inst = try comptimeExpr(gz, scope, .{ .ty = .u32_type }, member.ast.align_expr);
+                    fields_data.appendAssumeCapacity(@enumToInt(align_inst));
+                }
+                if (have_value) {
+                    const default_inst = try comptimeExpr(gz, scope, .{ .ty = field_type }, member.ast.value_expr);
+                    fields_data.appendAssumeCapacity(@enumToInt(default_inst));
+                }
+
+                member_index += 1;
+                if (member_index < container_decl.ast.members.len) {
+                    if (member_index % 16 == 0) {
+                        try bit_bag.append(gpa, cur_bit_bag);
+                        cur_bit_bag = 0;
+                    }
+                } else {
+                    break;
+                }
+            }
+            const empty_slot_count = 16 - ((member_index - 1) % 16);
+            cur_bit_bag >>= @intCast(u5, empty_slot_count * 2);
+
+            const result = try gz.addPlNode(.struct_decl, node, zir.Inst.StructDecl{
+                .fields_len = @intCast(u32, container_decl.ast.members.len),
+            });
+            try astgen.extra.ensureCapacity(gpa, astgen.extra.items.len +
+                bit_bag.items.len + 1 + fields_data.items.len);
+            astgen.extra.appendSliceAssumeCapacity(bit_bag.items); // Likely empty.
+            astgen.extra.appendAssumeCapacity(cur_bit_bag);
+            astgen.extra.appendSliceAssumeCapacity(fields_data.items);
+            return rvalue(gz, scope, rl, result, node);
+        },
+        .keyword_union => {
+            return mod.failTok(scope, container_decl.ast.main_token, "TODO AstGen for union decl", .{});
+        },
+        .keyword_enum => {
+            return mod.failTok(scope, container_decl.ast.main_token, "TODO AstGen for enum decl", .{});
+        },
+        .keyword_opaque => {
+            const result = try gz.addNode(.opaque_decl, node);
+            return rvalue(gz, scope, rl, result, node);
+        },
+        else => unreachable,
+    }
 }
 
 fn errorSetDecl(
@@ -2809,10 +2930,10 @@ fn switchExpr(
     // This is the header as well as the optional else prong body, as well as all the
     // scalar cases.
     // At the end we will memcpy this into place.
-    var scalar_cases_payload = std.ArrayListUnmanaged(u32){};
+    var scalar_cases_payload = ArrayListUnmanaged(u32){};
     defer scalar_cases_payload.deinit(gpa);
     // Same deal, but this is only the `extra` data for the multi cases.
-    var multi_cases_payload = std.ArrayListUnmanaged(u32){};
+    var multi_cases_payload = ArrayListUnmanaged(u32){};
     defer multi_cases_payload.deinit(gpa);
 
     var block_scope: GenZir = .{
src/Sema.zig
@@ -259,6 +259,12 @@ pub fn analyzeBody(
             .typeof_elem => try sema.zirTypeofElem(block, inst),
             .typeof_peer => try sema.zirTypeofPeer(block, inst),
             .xor => try sema.zirBitwise(block, inst, .xor),
+            .struct_init_empty => try sema.zirStructInitEmpty(block, inst),
+
+            .struct_decl => try sema.zirStructDecl(block, inst),
+            .enum_decl => try sema.zirEnumDecl(block, inst),
+            .union_decl => try sema.zirUnionDecl(block, inst),
+            .opaque_decl => try sema.zirOpaqueDecl(block, inst),
 
             // Instructions that we know to *always* be noreturn based solely on their tag.
             // These functions match the return type of analyzeBody so that we can
@@ -514,6 +520,56 @@ fn zirCoerceResultPtr(sema: *Sema, block: *Scope.Block, inst: zir.Inst.Index) In
     return sema.mod.fail(&block.base, sema.src, "TODO implement zirCoerceResultPtr", .{});
 }
 
+fn zirStructDecl(sema: *Sema, block: *Scope.Block, inst: zir.Inst.Index) InnerError!*Inst {
+    const tracy = trace(@src());
+    defer tracy.end();
+
+    const inst_data = sema.code.instructions.items(.data)[inst].pl_node;
+    const src = inst_data.src();
+    const extra = sema.code.extraData(zir.Inst.Block, inst_data.payload_index);
+
+    return sema.mod.fail(&block.base, sema.src, "TODO implement zirStructDecl", .{});
+
+    //const new_decl = try sema.mod.createAnonymousDecl(&block.base, &new_decl_arena, .{
+    //    .ty = decl_ty,
+    //    .val = decl_val,
+    //});
+    //return sema.analyzeDeclVal(block, src, new_decl);
+}
+
+fn zirEnumDecl(sema: *Sema, block: *Scope.Block, inst: zir.Inst.Index) InnerError!*Inst {
+    const tracy = trace(@src());
+    defer tracy.end();
+
+    const inst_data = sema.code.instructions.items(.data)[inst].pl_node;
+    const src = inst_data.src();
+    const extra = sema.code.extraData(zir.Inst.Block, inst_data.payload_index);
+
+    return sema.mod.fail(&block.base, sema.src, "TODO implement zirEnumDecl", .{});
+}
+
+fn zirUnionDecl(sema: *Sema, block: *Scope.Block, inst: zir.Inst.Index) InnerError!*Inst {
+    const tracy = trace(@src());
+    defer tracy.end();
+
+    const inst_data = sema.code.instructions.items(.data)[inst].pl_node;
+    const src = inst_data.src();
+    const extra = sema.code.extraData(zir.Inst.Block, inst_data.payload_index);
+
+    return sema.mod.fail(&block.base, sema.src, "TODO implement zirUnionDecl", .{});
+}
+
+fn zirOpaqueDecl(sema: *Sema, block: *Scope.Block, inst: zir.Inst.Index) InnerError!*Inst {
+    const tracy = trace(@src());
+    defer tracy.end();
+
+    const inst_data = sema.code.instructions.items(.data)[inst].pl_node;
+    const src = inst_data.src();
+    const extra = sema.code.extraData(zir.Inst.Block, inst_data.payload_index);
+
+    return sema.mod.fail(&block.base, sema.src, "TODO implement zirOpaqueDecl", .{});
+}
+
 fn zirRetPtr(sema: *Sema, block: *Scope.Block, inst: zir.Inst.Index) InnerError!*Inst {
     const tracy = trace(@src());
     defer tracy.end();
@@ -3867,6 +3923,20 @@ fn zirPtrType(sema: *Sema, block: *Scope.Block, inst: zir.Inst.Index) InnerError
     return sema.mod.constType(sema.arena, src, ty);
 }
 
+fn zirStructInitEmpty(sema: *Sema, block: *Scope.Block, inst: zir.Inst.Index) InnerError!*Inst {
+    const tracy = trace(@src());
+    defer tracy.end();
+
+    const inst_data = sema.code.instructions.items(.data)[inst].un_node;
+    const src = inst_data.src();
+    const struct_type = try sema.resolveType(block, src, inst_data.operand);
+
+    return sema.mod.constInst(sema.arena, src, .{
+        .ty = struct_type,
+        .val = Value.initTag(.empty_struct_value),
+    });
+}
+
 fn requireFunctionBlock(sema: *Sema, block: *Scope.Block, src: LazySrcLoc) !void {
     if (sema.func == null) {
         return sema.mod.fail(&block.base, src, "instruction illegal outside function body", .{});
src/type.zig
@@ -93,6 +93,7 @@ pub const Type = extern union {
             .anyerror_void_error_union, .error_union => return .ErrorUnion,
 
             .empty_struct => return .Struct,
+            .empty_struct_literal => return .Struct,
 
             .var_args_param => unreachable, // can be any type
         }
@@ -530,6 +531,7 @@ pub const Type = extern union {
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .var_args_param,
+            .empty_struct_literal,
             => unreachable,
 
             .array_u8,
@@ -672,8 +674,7 @@ pub const Type = extern union {
                 .@"null" => return out_stream.writeAll("@Type(.Null)"),
                 .@"undefined" => return out_stream.writeAll("@Type(.Undefined)"),
 
-                // TODO this should print the structs name
-                .empty_struct => return out_stream.writeAll("struct {}"),
+                .empty_struct, .empty_struct_literal => return out_stream.writeAll("struct {}"),
                 .anyerror_void_error_union => return out_stream.writeAll("anyerror!void"),
                 .const_slice_u8 => return out_stream.writeAll("[]const u8"),
                 .fn_noreturn_no_args => return out_stream.writeAll("fn() noreturn"),
@@ -960,6 +961,7 @@ pub const Type = extern union {
             .@"undefined",
             .enum_literal,
             .empty_struct,
+            .empty_struct_literal,
             .@"opaque",
             => false,
 
@@ -1108,6 +1110,7 @@ pub const Type = extern union {
             .@"undefined",
             .enum_literal,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -1135,6 +1138,7 @@ pub const Type = extern union {
             .enum_literal => unreachable,
             .single_const_pointer_to_comptime_int => unreachable,
             .empty_struct => unreachable,
+            .empty_struct_literal => unreachable,
             .inferred_alloc_const => unreachable,
             .inferred_alloc_mut => unreachable,
             .@"opaque" => unreachable,
@@ -1313,6 +1317,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .@"opaque",
             .var_args_param,
             => false,
@@ -1386,6 +1391,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .@"opaque",
             .var_args_param,
             => unreachable,
@@ -1478,6 +1484,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -1554,6 +1561,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -1639,6 +1647,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -1719,6 +1728,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -1841,6 +1851,7 @@ pub const Type = extern union {
             .error_set => unreachable,
             .error_set_single => unreachable,
             .empty_struct => unreachable,
+            .empty_struct_literal => unreachable,
             .inferred_alloc_const => unreachable,
             .inferred_alloc_mut => unreachable,
             .@"opaque" => unreachable,
@@ -1989,6 +2000,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2059,6 +2071,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2144,6 +2157,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2225,6 +2239,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2292,6 +2307,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2387,6 +2403,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2503,6 +2520,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2585,6 +2603,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2666,6 +2685,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2747,6 +2767,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2825,6 +2846,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2903,6 +2925,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -2981,6 +3004,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -3046,7 +3070,7 @@ pub const Type = extern union {
             .var_args_param,
             => return null,
 
-            .empty_struct => return Value.initTag(.empty_struct_value),
+            .empty_struct, .empty_struct_literal => return Value.initTag(.empty_struct_value),
             .void => return Value.initTag(.void_value),
             .noreturn => return Value.initTag(.unreachable_value),
             .@"null" => return Value.initTag(.null_value),
@@ -3149,6 +3173,7 @@ pub const Type = extern union {
             .error_set,
             .error_set_single,
             .empty_struct,
+            .empty_struct_literal,
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .@"opaque",
@@ -3241,6 +3266,7 @@ pub const Type = extern union {
             .inferred_alloc_const,
             .inferred_alloc_mut,
             .var_args_param,
+            .empty_struct_literal,
             => unreachable,
 
             .empty_struct => self.castTag(.empty_struct).?.data,
@@ -3361,6 +3387,8 @@ pub const Type = extern union {
         /// This is a special type for variadic parameters of a function call.
         /// Casts to it will validate that the type can be passed to a c calling convetion function.
         var_args_param,
+        /// Same as `empty_struct` except it has an empty namespace.
+        empty_struct_literal,
         /// This is a special value that tracks a set of types that have been stored
         /// to an inferred allocation. It does not support most of the normal type queries.
         /// However it does respond to `isConstPtr`, `ptrSize`, `zigTypeTag`, etc.
@@ -3445,6 +3473,7 @@ pub const Type = extern union {
                 .inferred_alloc_const,
                 .inferred_alloc_mut,
                 .var_args_param,
+                .empty_struct_literal,
                 => @compileError("Type Tag " ++ @tagName(t) ++ " has no payload"),
 
                 .array_u8,
src/zir.zig
@@ -270,6 +270,21 @@ pub const Inst = struct {
         /// A comptime known value.
         /// Uses the `const` union field.
         @"const",
+        /// A struct type definition. Contains references to ZIR instructions for
+        /// the field types, defaults, and alignments.
+        /// Uses the `pl_node` union field. Payload is `StructDecl`.
+        struct_decl,
+        /// A union type definition. Contains references to ZIR instructions for
+        /// the field types and optional type tag expression.
+        /// Uses the `pl_node` union field. Payload is `UnionDecl`.
+        union_decl,
+        /// An enum type definition. Contains references to ZIR instructions for
+        /// the field value expressions and optional type tag expression.
+        /// Uses the `pl_node` union field. Payload is `EnumDecl`.
+        enum_decl,
+        /// An opaque type definition. Provides an AST node only.
+        /// Uses the `node` union field.
+        opaque_decl,
         /// Declares the beginning of a statement. Used for debug info.
         /// Uses the `node` union field.
         dbg_stmt_node,
@@ -642,6 +657,9 @@ pub const Inst = struct {
         /// as well as missing fields, if applicable.
         /// Uses the `pl_node` field. Payload is `Block`.
         validate_struct_init_ptr,
+        /// A struct literal with a specified type, with no fields.
+        /// Uses the `un_node` field.
+        struct_init_empty,
 
         /// Returns whether the instruction is one of the control flow "noreturn" types.
         /// Function calls do not count.
@@ -688,6 +706,10 @@ pub const Inst = struct {
                 .cmp_neq,
                 .coerce_result_ptr,
                 .@"const",
+                .struct_decl,
+                .union_decl,
+                .enum_decl,
+                .opaque_decl,
                 .dbg_stmt_node,
                 .decl_ref,
                 .decl_val,
@@ -790,6 +812,7 @@ pub const Inst = struct {
                 .switch_block_ref_under,
                 .switch_block_ref_under_multi,
                 .validate_struct_init_ptr,
+                .struct_init_empty,
                 => false,
 
                 .@"break",
@@ -893,6 +916,8 @@ pub const Inst = struct {
         bool_true,
         /// `false`
         bool_false,
+        /// `.{}` (untyped)
+        empty_struct,
         /// `0` (usize)
         zero_usize,
         /// `1` (usize)
@@ -1104,6 +1129,10 @@ pub const Inst = struct {
                 .ty = Type.initTag(.bool),
                 .val = Value.initTag(.bool_false),
             },
+            .empty_struct = .{
+                .ty = Type.initTag(.empty_struct_literal),
+                .val = Value.initTag(.empty_struct_value),
+            },
         });
     };
 
@@ -1427,6 +1456,48 @@ pub const Inst = struct {
         dest_type: Ref,
         operand: Ref,
     };
+
+    /// Trailing:
+    /// 0. has_bits: u32 // for every 16 fields
+    ///    - sets of 2 bits:
+    ///      0b0X: whether corresponding field has an align expression
+    ///      0bX0: whether corresponding field has a default expression
+    /// 1. fields: { // for every fields_len
+    ///        field_name: u32,
+    ///        field_type: Ref,
+    ///        align: Ref, // if corresponding bit is set
+    ///        default_value: Ref, // if corresponding bit is set
+    ///    }
+    pub const StructDecl = struct {
+        fields_len: u32,
+    };
+
+    /// Trailing:
+    /// 0. has_bits: u32 // for every 32 fields
+    ///    - the bit is whether corresponding field has an value expression
+    /// 1. field_name: u32 // for every field: null terminated string index
+    /// 2. value: Ref // for every field for which corresponding bit is set
+    pub const EnumDecl = struct {
+        /// Can be `Ref.none`.
+        tag_type: Ref,
+        fields_len: u32,
+    };
+
+    /// Trailing:
+    /// 0. has_bits: u32 // for every 10 fields (+1)
+    ///    - first bit is special: set if and only if auto enum tag is enabled.
+    ///    - sets of 3 bits:
+    ///      0b00X: whether corresponding field has a type expression
+    ///      0b0X0: whether corresponding field has a align expression
+    ///      0bX00: whether corresponding field has a tag value expression
+    /// 1. field_name: u32 // for every field: null terminated string index
+    /// 2. opt_exprs // Ref for every field for which corresponding bit is set
+    ///    - interleaved. type if present, align if present, tag value if present.
+    pub const UnionDecl = struct {
+        /// Can be `Ref.none`.
+        tag_type: Ref,
+        fields_len: u32,
+    };
 };
 
 pub const SpecialProng = enum { none, @"else", under };
@@ -1500,6 +1571,7 @@ const Writer = struct {
             .is_err_ptr,
             .typeof,
             .typeof_elem,
+            .struct_init_empty,
             => try self.writeUnNode(stream, inst),
 
             .ref,
@@ -1536,6 +1608,8 @@ const Writer = struct {
             .slice_start,
             .slice_end,
             .slice_sentinel,
+            .union_decl,
+            .enum_decl,
             => try self.writePlNode(stream, inst),
 
             .add,
@@ -1581,6 +1655,8 @@ const Writer = struct {
             .condbr_inline,
             => try self.writePlNodeCondBr(stream, inst),
 
+            .struct_decl => try self.writeStructDecl(stream, inst),
+
             .switch_block => try self.writePlNodeSwitchBr(stream, inst, .none),
             .switch_block_else => try self.writePlNodeSwitchBr(stream, inst, .@"else"),
             .switch_block_under => try self.writePlNodeSwitchBr(stream, inst, .under),
@@ -1610,6 +1686,7 @@ const Writer = struct {
             .as_node => try self.writeAs(stream, inst),
 
             .breakpoint,
+            .opaque_decl,
             .dbg_stmt_node,
             .ret_ptr,
             .ret_type,
@@ -1808,6 +1885,62 @@ const Writer = struct {
         try self.writeSrc(stream, inst_data.src());
     }
 
+    fn writeStructDecl(self: *Writer, stream: anytype, inst: Inst.Index) !void {
+        const inst_data = self.code.instructions.items(.data)[inst].pl_node;
+        const extra = self.code.extraData(Inst.StructDecl, inst_data.payload_index);
+        const fields_len = extra.data.fields_len;
+        const bit_bags_count = std.math.divCeil(usize, fields_len, 16) catch unreachable;
+
+        try stream.writeAll("{\n");
+        self.indent += 2;
+
+        var field_index: usize = extra.end + bit_bags_count;
+        var bit_bag_index: usize = extra.end;
+        var cur_bit_bag: u32 = undefined;
+        var field_i: u32 = 0;
+        while (field_i < fields_len) : (field_i += 1) {
+            if (field_i % 16 == 0) {
+                cur_bit_bag = self.code.extra[bit_bag_index];
+                bit_bag_index += 1;
+            }
+            const has_align = @truncate(u1, cur_bit_bag) != 0;
+            cur_bit_bag >>= 1;
+            const has_default = @truncate(u1, cur_bit_bag) != 0;
+            cur_bit_bag >>= 1;
+
+            const field_name = self.code.nullTerminatedString(self.code.extra[field_index]);
+            field_index += 1;
+            const field_type = @intToEnum(Inst.Ref, self.code.extra[field_index]);
+            field_index += 1;
+
+            try stream.writeByteNTimes(' ', self.indent);
+            try stream.print("{}: ", .{std.zig.fmtId(field_name)});
+            try self.writeInstRef(stream, field_type);
+
+            if (has_align) {
+                const align_ref = @intToEnum(Inst.Ref, self.code.extra[field_index]);
+                field_index += 1;
+
+                try stream.writeAll(" align(");
+                try self.writeInstRef(stream, align_ref);
+                try stream.writeAll(")");
+            }
+            if (has_default) {
+                const default_ref = @intToEnum(Inst.Ref, self.code.extra[field_index]);
+                field_index += 1;
+
+                try stream.writeAll(" = ");
+                try self.writeInstRef(stream, default_ref);
+            }
+            try stream.writeAll(",\n");
+        }
+
+        self.indent -= 2;
+        try stream.writeByteNTimes(' ', self.indent);
+        try stream.writeAll("}) ");
+        try self.writeSrc(stream, inst_data.src());
+    }
+
     fn writePlNodeSwitchBr(
         self: *Writer,
         stream: anytype,