Merge pull request #11749 from Vexu/stage2

Stage2: improve AstGen for array init expressions

4 files changed, 117 insertions, 122 deletions

diff --git a/src/AstGen.zig b/src/AstGen.zig
index ba27165cea..1a79e044fa 100644
--- a/src/AstGen.zig
+++ b/src/AstGen.zig
@@ -1276,12 +1276,10 @@ fn arrayInitExpr(
     const types: struct {
         array: Zir.Inst.Ref,
         elem: Zir.Inst.Ref,
-        sentinel: Zir.Inst.Ref,
     } = inst: {
         if (array_init.ast.type_expr == 0) break :inst .{
             .array = .none,
             .elem = .none,
-            .sentinel = .none,
         };
 
         infer: {
@@ -1301,7 +1299,6 @@ fn arrayInitExpr(
                     break :inst .{
                         .array = array_type_inst,
                         .elem = elem_type,
-                        .sentinel = .none,
                     };
                 } else {
                     const sentinel = try comptimeExpr(gz, scope, .{ .ty = elem_type }, array_type.ast.sentinel);
@@ -1317,50 +1314,38 @@ fn arrayInitExpr(
                     break :inst .{
                         .array = array_type_inst,
                         .elem = elem_type,
-                        .sentinel = sentinel,
                     };
                 }
             }
         }
         const array_type_inst = try typeExpr(gz, scope, array_init.ast.type_expr);
         _ = try gz.addUnNode(.validate_array_init_ty, array_type_inst, node);
-        const elem_type = try gz.addUnNode(.elem_type, array_type_inst, array_init.ast.type_expr);
         break :inst .{
             .array = array_type_inst,
-            .elem = elem_type,
-            .sentinel = .none,
+            .elem = .none,
         };
     };
 
     switch (rl) {
         .discard => {
+            // TODO elements should still be coerced if type is provided
             for (array_init.ast.elements) |elem_init| {
                 _ = try expr(gz, scope, .discard, elem_init);
             }
             return Zir.Inst.Ref.void_value;
         },
         .ref => {
-            if (types.array != .none) {
-                return arrayInitExprRlTy(gz, scope, node, array_init.ast.elements, types.elem, types.sentinel, true);
-            } else {
-                return arrayInitExprRlNone(gz, scope, node, array_init.ast.elements, .array_init_anon_ref);
-            }
+            const tag: Zir.Inst.Tag = if (types.array != .none) .array_init_ref else .array_init_anon_ref;
+            return arrayInitExprInner(gz, scope, node, array_init.ast.elements, types.array, types.elem, tag);
         },
         .none => {
-            if (types.array != .none) {
-                return arrayInitExprRlTy(gz, scope, node, array_init.ast.elements, types.elem, types.sentinel, false);
-            } else {
-                return arrayInitExprRlNone(gz, scope, node, array_init.ast.elements, .array_init_anon);
-            }
+            const tag: Zir.Inst.Tag = if (types.array != .none) .array_init else .array_init_anon;
+            return arrayInitExprInner(gz, scope, node, array_init.ast.elements, types.array, types.elem, tag);
         },
         .ty, .coerced_ty => {
-            if (types.array != .none) {
-                const result = try arrayInitExprRlTy(gz, scope, node, array_init.ast.elements, types.elem, types.sentinel, false);
-                return rvalue(gz, rl, result, node);
-            } else {
-                const result = try arrayInitExprRlNone(gz, scope, node, array_init.ast.elements, .array_init_anon);
-                return rvalue(gz, rl, result, node);
-            }
+            const tag: Zir.Inst.Tag = if (types.array != .none) .array_init else .array_init_anon;
+            const result = try arrayInitExprInner(gz, scope, node, array_init.ast.elements, types.array, types.elem, tag);
+            return rvalue(gz, rl, result, node);
         },
         .ptr => |ptr_inst| {
             return arrayInitExprRlPtr(gz, scope, rl, node, ptr_inst, array_init.ast.elements, types.array);
@@ -1410,52 +1395,47 @@ fn arrayInitExprRlNone(
     return try gz.addPlNodePayloadIndex(tag, node, payload_index);
 }
 
-fn arrayInitExprRlTy(
+fn arrayInitExprInner(
     gz: *GenZir,
     scope: *Scope,
     node: Ast.Node.Index,
     elements: []const Ast.Node.Index,
-    elem_ty_inst: Zir.Inst.Ref,
-    sentinel: Zir.Inst.Ref,
-    ref: bool,
+    array_ty_inst: Zir.Inst.Ref,
+    elem_ty: Zir.Inst.Ref,
+    tag: Zir.Inst.Tag,
 ) InnerError!Zir.Inst.Ref {
     const astgen = gz.astgen;
 
-    const info: struct {
-        len: usize,
-        tag: Zir.Inst.Tag,
-    } = blk: {
-        if (sentinel != .none) {
-            break :blk .{
-                .len = elements.len + 1,
-                .tag = if (ref) .array_init_sent_ref else .array_init_sent,
-            };
-        } else {
-            break :blk .{
-                .len = elements.len,
-                .tag = if (ref) .array_init_ref else .array_init,
-            };
-        }
-    };
-
+    const len = elements.len + @boolToInt(array_ty_inst != .none);
     const payload_index = try addExtra(astgen, Zir.Inst.MultiOp{
-        .operands_len = @intCast(u32, info.len),
+        .operands_len = @intCast(u32, len),
     });
-    var extra_index = try reserveExtra(astgen, info.len);
-
-    const elem_rl: ResultLoc = .{ .ty = elem_ty_inst };
-    for (elements) |elem_init| {
-        const elem_ref = try expr(gz, scope, elem_rl, elem_init);
-        astgen.extra.items[extra_index] = @enumToInt(elem_ref);
+    var extra_index = try reserveExtra(astgen, len);
+    if (array_ty_inst != .none) {
+        astgen.extra.items[extra_index] = @enumToInt(array_ty_inst);
         extra_index += 1;
     }
 
-    if (sentinel != .none) {
-        astgen.extra.items[extra_index] = @enumToInt(sentinel);
+    for (elements) |elem_init, i| {
+        const rl = if (elem_ty != .none)
+            ResultLoc{ .coerced_ty = elem_ty }
+        else if (array_ty_inst != .none and nodeMayNeedMemoryLocation(astgen.tree, elem_init, true)) rl: {
+            const ty_expr = try gz.add(.{
+                .tag = .elem_type_index,
+                .data = .{ .bin = .{
+                    .lhs = array_ty_inst,
+                    .rhs = @intToEnum(Zir.Inst.Ref, i),
+                } },
+            });
+            break :rl ResultLoc{ .coerced_ty = ty_expr };
+        } else ResultLoc{ .none = {} };
+
+        const elem_ref = try expr(gz, scope, rl, elem_init);
+        astgen.extra.items[extra_index] = @enumToInt(elem_ref);
         extra_index += 1;
     }
 
-    return try gz.addPlNodePayloadIndex(info.tag, node, payload_index);
+    return try gz.addPlNodePayloadIndex(tag, node, payload_index);
 }
 
 fn arrayInitExprRlPtr(
@@ -2243,8 +2223,8 @@ fn unusedResultExpr(gz: *GenZir, scope: *Scope, statement: Ast.Node.Index) Inner
             .array_mul,
             .array_type,
             .array_type_sentinel,
+            .elem_type_index,
             .vector_type,
-            .elem_type,
             .indexable_ptr_len,
             .anyframe_type,
             .as,
@@ -2347,10 +2327,8 @@ fn unusedResultExpr(gz: *GenZir, scope: *Scope, statement: Ast.Node.Index) Inner
             .struct_init_anon_ref,
             .array_init,
             .array_init_anon,
-            .array_init_sent,
             .array_init_ref,
             .array_init_anon_ref,
-            .array_init_sent_ref,
             .union_init,
             .field_type,
             .field_type_ref,
diff --git a/src/Sema.zig b/src/Sema.zig
index e0310e5ad7..fc64e17789 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -726,7 +726,7 @@ fn analyzeBodyInner(
             .elem_ptr_imm                 => try sema.zirElemPtrImm(block, inst),
             .elem_val                     => try sema.zirElemVal(block, inst),
             .elem_val_node                => try sema.zirElemValNode(block, inst),
-            .elem_type                    => try sema.zirElemType(block, inst),
+            .elem_type_index              => try sema.zirElemTypeIndex(block, inst),
             .enum_literal                 => try sema.zirEnumLiteral(block, inst),
             .enum_to_int                  => try sema.zirEnumToInt(block, inst),
             .int_to_enum                  => try sema.zirIntToEnum(block, inst),
@@ -798,10 +798,8 @@ fn analyzeBodyInner(
             .struct_init_ref              => try sema.zirStructInit(block, inst, true),
             .struct_init_anon             => try sema.zirStructInitAnon(block, inst, false),
             .struct_init_anon_ref         => try sema.zirStructInitAnon(block, inst, true),
-            .array_init                   => try sema.zirArrayInit(block, inst, false, false),
-            .array_init_sent              => try sema.zirArrayInit(block, inst, false, true),
-            .array_init_ref               => try sema.zirArrayInit(block, inst, true, false),
-            .array_init_sent_ref          => try sema.zirArrayInit(block, inst, true, true),
+            .array_init                   => try sema.zirArrayInit(block, inst, false),
+            .array_init_ref               => try sema.zirArrayInit(block, inst, true),
             .array_init_anon              => try sema.zirArrayInitAnon(block, inst, false),
             .array_init_anon_ref          => try sema.zirArrayInitAnon(block, inst, true),
             .union_init                   => try sema.zirUnionInit(block, inst),
@@ -3024,7 +3022,10 @@ fn zirArrayBasePtr(
     const elem_ty = sema.typeOf(base_ptr).childType();
     switch (elem_ty.zigTypeTag()) {
         .Array, .Vector => return base_ptr,
-        .Struct => if (elem_ty.isTuple()) return base_ptr,
+        .Struct => if (elem_ty.isTuple()) {
+            // TODO validate element count
+            return base_ptr;
+        },
         else => {},
     }
     return sema.failWithArrayInitNotSupported(block, src, sema.typeOf(start_ptr).childType());
@@ -3065,7 +3066,10 @@ fn validateArrayInitTy(
 
     switch (ty.zigTypeTag()) {
         .Array, .Vector => return,
-        .Struct => if (ty.isTuple()) return,
+        .Struct => if (ty.isTuple()) {
+            // TODO validate element count
+            return;
+        },
         else => {},
     }
     return sema.failWithArrayInitNotSupported(block, src, ty);
@@ -5808,12 +5812,17 @@ fn zirOptionalType(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileErro
     return sema.addType(opt_type);
 }
 
-fn zirElemType(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Air.Inst.Ref {
-    const inst_data = sema.code.instructions.items(.data)[inst].un_node;
-    const src = inst_data.src();
-    const array_type = try sema.resolveType(block, src, inst_data.operand);
-    const elem_type = array_type.elemType();
-    return sema.addType(elem_type);
+fn zirElemTypeIndex(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Air.Inst.Ref {
+    const bin = sema.code.instructions.items(.data)[inst].bin;
+    const indexable_ty = try sema.resolveType(block, .unneeded, bin.lhs);
+    assert(indexable_ty.isIndexable()); // validated by a previous instruction
+    if (indexable_ty.zigTypeTag() == .Struct) {
+        const elem_type = indexable_ty.tupleFields().types[@enumToInt(bin.rhs)];
+        return sema.addType(elem_type);
+    } else {
+        const elem_type = indexable_ty.elemType2();
+        return sema.addType(elem_type);
+    }
 }
 
 fn zirVectorType(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Air.Inst.Ref {
@@ -13280,6 +13289,8 @@ fn zirStructInit(
         try sema.requireRuntimeBlock(block, src);
         try sema.queueFullTypeResolution(resolved_ty);
         return block.addUnionInit(resolved_ty, field_index, init_inst);
+    } else if (resolved_ty.isAnonStruct()) {
+        return sema.fail(block, src, "TODO anon struct init validation", .{});
     }
     unreachable;
 }
@@ -13436,7 +13447,6 @@ fn zirArrayInit(
     block: *Block,
     inst: Zir.Inst.Index,
     is_ref: bool,
-    is_sent: bool,
 ) CompileError!Air.Inst.Ref {
     const gpa = sema.gpa;
     const inst_data = sema.code.instructions.items(.data)[inst].pl_node;
@@ -13444,30 +13454,26 @@ fn zirArrayInit(
 
     const extra = sema.code.extraData(Zir.Inst.MultiOp, inst_data.payload_index);
     const args = sema.code.refSlice(extra.end, extra.data.operands_len);
-    assert(args.len != 0);
+    assert(args.len >= 2); // array_ty + at least one element
 
-    const resolved_args = try gpa.alloc(Air.Inst.Ref, args.len);
-    defer gpa.free(resolved_args);
-
-    for (args) |arg, i| resolved_args[i] = try sema.resolveInst(arg);
+    const array_ty = try sema.resolveType(block, src, args[0]);
+    const sentinel_val = array_ty.sentinel();
 
-    const elem_ty = sema.typeOf(resolved_args[0]);
-    const array_ty = blk: {
-        if (!is_sent) {
-            break :blk try Type.Tag.array.create(sema.arena, .{
-                .len = resolved_args.len,
-                .elem_type = elem_ty,
-            });
-        }
+    const resolved_args = try gpa.alloc(Air.Inst.Ref, args.len - 1 + @boolToInt(sentinel_val != null));
+    defer gpa.free(resolved_args);
+    for (args[1..]) |arg, i| {
+        const resolved_arg = try sema.resolveInst(arg);
+        const arg_src = src; // TODO better source location
+        const elem_ty = if (array_ty.zigTypeTag() == .Struct)
+            array_ty.tupleFields().types[i]
+        else
+            array_ty.elemType2();
+        resolved_args[i] = try sema.coerce(block, elem_ty, resolved_arg, arg_src);
+    }
 
-        const sentinel_ref = resolved_args[resolved_args.len - 1];
-        const val = try sema.resolveConstValue(block, src, sentinel_ref);
-        break :blk try Type.Tag.array_sentinel.create(sema.arena, .{
-            .len = resolved_args.len - 1,
-            .sentinel = val,
-            .elem_type = elem_ty,
-        });
-    };
+    if (sentinel_val) |some| {
+        resolved_args[resolved_args.len - 1] = try sema.addConstant(array_ty.elemType2(), some);
+    }
 
     const opt_runtime_src: ?LazySrcLoc = for (resolved_args) |arg| {
         const arg_src = src; // TODO better source location
@@ -13488,7 +13494,7 @@ fn zirArrayInit(
     };
 
     try sema.requireRuntimeBlock(block, runtime_src);
-    try sema.queueFullTypeResolution(elem_ty);
+    try sema.queueFullTypeResolution(array_ty);
 
     if (is_ref) {
         const target = sema.mod.getTarget();
@@ -13498,10 +13504,27 @@ fn zirArrayInit(
         });
         const alloc = try block.addTy(.alloc, alloc_ty);
 
+        if (array_ty.isTuple()) {
+            const types = array_ty.tupleFields().types;
+            for (resolved_args) |arg, i| {
+                const elem_ptr_ty = try Type.ptr(sema.arena, sema.mod, .{
+                    .mutable = true,
+                    .@"addrspace" = target_util.defaultAddressSpace(target, .local),
+                    .pointee_type = types[i],
+                });
+                const elem_ptr_ty_ref = try sema.addType(elem_ptr_ty);
+
+                const index = try sema.addIntUnsigned(Type.usize, i);
+                const elem_ptr = try block.addPtrElemPtrTypeRef(alloc, index, elem_ptr_ty_ref);
+                _ = try block.addBinOp(.store, elem_ptr, arg);
+            }
+            return alloc;
+        }
+
         const elem_ptr_ty = try Type.ptr(sema.arena, sema.mod, .{
             .mutable = true,
             .@"addrspace" = target_util.defaultAddressSpace(target, .local),
-            .pointee_type = elem_ty,
+            .pointee_type = array_ty.elemType2(),
         });
         const elem_ptr_ty_ref = try sema.addType(elem_ptr_ty);
 
@@ -13643,6 +13666,10 @@ fn fieldType(
     while (true) {
         switch (cur_ty.zigTypeTag()) {
             .Struct => {
+                if (cur_ty.isAnonStruct()) {
+                    const field_index = try sema.anonStructFieldIndex(block, cur_ty, field_name, field_src);
+                    return sema.addType(cur_ty.tupleFields().types[field_index]);
+                }
                 const struct_obj = cur_ty.castTag(.@"struct").?.data;
                 const field = struct_obj.fields.get(field_name) orelse
                     return sema.failWithBadStructFieldAccess(block, struct_obj, field_src, field_name);
diff --git a/src/Zir.zig b/src/Zir.zig
index c722457303..7516a5a873 100644
--- a/src/Zir.zig
+++ b/src/Zir.zig
@@ -221,9 +221,9 @@ pub const Inst = struct {
         /// Uses the `pl_node` union field with `Bin` payload.
         /// lhs is length, rhs is element type.
         vector_type,
-        /// Given an array type, returns the element type.
-        /// Uses the `un_node` union field.
-        elem_type,
+        /// Given an indexable type, returns the type of the element at given index.
+        /// Uses the `bin` union field. lhs is the indexable type, rhs is the index.
+        elem_type_index,
         /// Given a pointer to an indexable object, returns the len property. This is
         /// used by for loops. This instruction also emits a for-loop specific compile
         /// error if the indexable object is not indexable.
@@ -737,20 +737,12 @@ pub const Inst = struct {
         /// Array initialization syntax.
         /// Uses the `pl_node` field. Payload is `MultiOp`.
         array_init,
-        /// Array initialization with sentinel.
-        /// Uses the `pl_node` field. Payload is `MultiOp`.
-        /// Final op in MultiOp is the sentinel.
-        array_init_sent,
         /// Anonymous array initialization syntax.
         /// Uses the `pl_node` field. Payload is `MultiOp`.
         array_init_anon,
         /// Array initialization syntax, make the result a pointer.
         /// Uses the `pl_node` field. Payload is `MultiOp`.
         array_init_ref,
-        /// Array initialization with sentinel.
-        /// Uses the `pl_node` field. Payload is `MultiOp`.
-        /// Final op in MultiOp is the sentinel.
-        array_init_sent_ref,
         /// Anonymous array initialization syntax, make the result a pointer.
         /// Uses the `pl_node` field. Payload is `MultiOp`.
         array_init_anon_ref,
@@ -1019,7 +1011,7 @@ pub const Inst = struct {
                 .array_type,
                 .array_type_sentinel,
                 .vector_type,
-                .elem_type,
+                .elem_type_index,
                 .indexable_ptr_len,
                 .anyframe_type,
                 .as,
@@ -1153,10 +1145,8 @@ pub const Inst = struct {
                 .struct_init_anon,
                 .struct_init_anon_ref,
                 .array_init,
-                .array_init_sent,
                 .array_init_anon,
                 .array_init_ref,
-                .array_init_sent_ref,
                 .array_init_anon_ref,
                 .union_init,
                 .field_type,
@@ -1314,7 +1304,7 @@ pub const Inst = struct {
                 .array_type,
                 .array_type_sentinel,
                 .vector_type,
-                .elem_type,
+                .elem_type_index,
                 .indexable_ptr_len,
                 .anyframe_type,
                 .as,
@@ -1426,10 +1416,8 @@ pub const Inst = struct {
                 .struct_init_anon,
                 .struct_init_anon_ref,
                 .array_init,
-                .array_init_sent,
                 .array_init_anon,
                 .array_init_ref,
-                .array_init_sent_ref,
                 .array_init_anon_ref,
                 .union_init,
                 .field_type,
@@ -1554,7 +1542,7 @@ pub const Inst = struct {
                 .array_type = .bin,
                 .array_type_sentinel = .pl_node,
                 .vector_type = .pl_node,
-                .elem_type = .un_node,
+                .elem_type_index = .bin,
                 .indexable_ptr_len = .un_node,
                 .anyframe_type = .un_node,
                 .as = .bin,
@@ -1688,10 +1676,8 @@ pub const Inst = struct {
                 .struct_init_anon = .pl_node,
                 .struct_init_anon_ref = .pl_node,
                 .array_init = .pl_node,
-                .array_init_sent = .pl_node,
                 .array_init_anon = .pl_node,
                 .array_init_ref = .pl_node,
-                .array_init_sent_ref = .pl_node,
                 .array_init_anon_ref = .pl_node,
                 .union_init = .pl_node,
                 .type_info = .un_node,
diff --git a/src/print_zir.zig b/src/print_zir.zig
index 1f243acc30..6bab2e5628 100644
--- a/src/print_zir.zig
+++ b/src/print_zir.zig
@@ -152,6 +152,8 @@ const Writer = struct {
             .store_to_inferred_ptr,
             => try self.writeBin(stream, inst),
 
+            .elem_type_index => try self.writeElemTypeIndex(stream, inst),
+
             .alloc,
             .alloc_mut,
             .alloc_comptime_mut,
@@ -226,7 +228,6 @@ const Writer = struct {
             .pop_count,
             .byte_swap,
             .bit_reverse,
-            .elem_type,
             .@"resume",
             .@"await",
             .switch_cond,
@@ -268,10 +269,6 @@ const Writer = struct {
             .array_init_anon_ref,
             => try self.writeArrayInit(stream, inst),
 
-            .array_init_sent,
-            .array_init_sent_ref,
-            => try self.writeArrayInitSent(stream, inst),
-
             .slice_start => try self.writeSliceStart(stream, inst),
             .slice_end => try self.writeSliceEnd(stream, inst),
             .slice_sentinel => try self.writeSliceSentinel(stream, inst),
@@ -543,6 +540,12 @@ const Writer = struct {
         try stream.writeByte(')');
     }
 
+    fn writeElemTypeIndex(self: *Writer, stream: anytype, inst: Zir.Inst.Index) !void {
+        const inst_data = self.code.instructions.items(.data)[inst].bin;
+        try self.writeInstRef(stream, inst_data.lhs);
+        try stream.print(", {d})", .{inst_data.rhs});
+    }
+
     fn writeUnNode(
         self: *Writer,
         stream: anytype,
@@ -2085,8 +2088,9 @@ const Writer = struct {
         const extra = self.code.extraData(Zir.Inst.MultiOp, inst_data.payload_index);
         const args = self.code.refSlice(extra.end, extra.data.operands_len);
 
-        try stream.writeAll(".{");
-        for (args) |arg, i| {
+        try self.writeInstRef(stream, args[0]);
+        try stream.writeAll("{");
+        for (args[1..]) |arg, i| {
             if (i != 0) try stream.writeAll(", ");
             try self.writeInstRef(stream, arg);
         }