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cbe: ignore comptime fields when generating tuple typedefs
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This vastly reduces the amount of deduplication state we need to deal with.
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@jacobly0
jacobly0 committed Nov 2, 2022
1 parent 5f31070 commit 37c104a
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Showing 2 changed files with 103 additions and 73 deletions.
175 changes: 103 additions & 72 deletions src/codegen/c.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,8 @@ pub const CValue = union(enum) {
constant: Air.Inst.Ref,
/// Index into the parameters
arg: usize,
/// Index into a tuple's fields
field: usize,
/// By-value
decl: Decl.Index,
decl_ref: Decl.Index,
Expand Down Expand Up @@ -1382,26 +1384,17 @@ pub const DeclGen = struct {
try buffer.appendSlice("typedef struct {\n");
{
const fields = t.tupleFields();
var empty = true;
var field_id: usize = 0;
for (fields.types) |field_ty, i| {
if (!field_ty.hasRuntimeBits()) continue;
const val = fields.values[i];
if (val.tag() != .unreachable_value) continue;

var field_name_buf: []const u8 = &.{};
defer dg.typedefs.allocator.free(field_name_buf);
const field_name = if (t.isTuple()) field_name: {
field_name_buf = try std.fmt.allocPrint(dg.typedefs.allocator, "field_{d}", .{i});
break :field_name field_name_buf;
} else t.structFieldName(i);
if (!field_ty.hasRuntimeBits() or fields.values[i].tag() != .unreachable_value) continue;

try buffer.append(' ');
try dg.renderTypeAndName(buffer.writer(), field_ty, .{ .identifier = field_name }, .Mut, 0, .Complete);
try dg.renderTypeAndName(buffer.writer(), field_ty, .{ .field = field_id }, .Mut, 0, .Complete);
try buffer.appendSlice(";\n");

empty = false;
field_id += 1;
}
if (empty) try buffer.appendSlice(" char empty_tuple;\n");
if (field_id == 0) try buffer.appendSlice(" char empty_tuple;\n");
}
const name_begin = buffer.items.len + "} ".len;
try buffer.writer().print("}} zig_T_{};\n", .{typeToCIdentifier(t, dg.module)});
Expand Down Expand Up @@ -1755,12 +1748,38 @@ pub const DeclGen = struct {
},
.Struct, .Union => |tag| if (tag == .Struct and t.containerLayout() == .Packed)
try dg.renderType(w, t.castTag(.@"struct").?.data.backing_int_ty, kind)
else if (kind == .Complete or t.isTupleOrAnonStruct()) {
else if (t.isTupleOrAnonStruct()) {
const ExpectedContents = struct { types: [8]Type, values: [8]Value };
var stack align(@alignOf(ExpectedContents)) =
std.heap.stackFallback(@sizeOf(ExpectedContents), dg.gpa);
const allocator = stack.get();

var tuple_storage = std.MultiArrayList(struct { type: Type, value: Value }){};
defer tuple_storage.deinit(allocator);
try tuple_storage.ensureTotalCapacity(allocator, t.structFieldCount());

const fields = t.tupleFields();
for (fields.values) |value, index|
if (value.tag() == .unreachable_value)
tuple_storage.appendAssumeCapacity(.{
.type = fields.types[index],
.value = value,
});

const tuple_slice = tuple_storage.slice();
var tuple_pl = Type.Payload.Tuple{ .data = .{
.types = tuple_slice.items(.type),
.values = tuple_slice.items(.value),
} };
const tuple_ty = Type.initPayload(&tuple_pl.base);

const name = dg.getTypedefName(tuple_ty) orelse
try dg.renderTupleTypedef(tuple_ty);

try w.writeAll(name);
} else if (kind == .Complete) {
const name = dg.getTypedefName(t) orelse switch (tag) {
.Struct => if (t.isTupleOrAnonStruct())
try dg.renderTupleTypedef(t)
else
try dg.renderStructTypedef(t),
.Struct => try dg.renderStructTypedef(t),
.Union => try dg.renderUnionTypedef(t),
else => unreachable,
};
Expand Down Expand Up @@ -1980,6 +1999,7 @@ pub const DeclGen = struct {
.local_ref => |i| return w.print("&t{d}", .{i}),
.constant => unreachable,
.arg => |i| return w.print("a{d}", .{i}),
.field => |i| return w.print("f{d}", .{i}),
.decl => |decl| return dg.renderDeclName(w, decl),
.decl_ref => |decl| {
try w.writeByte('&');
Expand All @@ -1998,6 +2018,7 @@ pub const DeclGen = struct {
.local_ref => |i| return w.print("t{d}", .{i}),
.constant => unreachable,
.arg => |i| return w.print("(*a{d})", .{i}),
.field => |i| return w.print("f{d}", .{i}),
.decl => |decl| {
try w.writeAll("(*");
try dg.renderDeclName(w, decl);
Expand All @@ -2022,7 +2043,7 @@ pub const DeclGen = struct {

fn writeCValueDerefMember(dg: *DeclGen, writer: anytype, c_value: CValue, member: CValue) !void {
switch (c_value) {
.none, .constant, .undef => unreachable,
.none, .constant, .field, .undef => unreachable,
.local, .arg, .decl, .identifier, .bytes => {
try dg.writeCValue(writer, c_value);
try writer.writeAll("->");
Expand Down Expand Up @@ -2868,7 +2889,7 @@ fn airRet(f: *Function, inst: Air.Inst.Index, is_ptr: bool) !CValue {
const array_local = try f.allocLocal(lowered_ret_ty, .Mut);
try writer.writeAll(";\n");
try writer.writeAll("memcpy(");
try f.writeCValueMember(writer, array_local, .{ .identifier = "array" });
try f.writeCValueMember(writer, array_local, .{ .field = 0 });
try writer.writeAll(", ");
if (deref)
try f.writeCValueDeref(writer, operand)
Expand Down Expand Up @@ -3114,13 +3135,13 @@ fn airOverflow(f: *Function, inst: Air.Inst.Index, operation: []const u8, info:
const local = try f.allocLocal(inst_ty, .Mut);
try w.writeAll(";\n");

try f.writeCValue(w, local, .Other);
try w.writeAll(".field_1 = zig_");
try f.writeCValueMember(w, local, .{ .field = 1 });
try w.writeAll(" = zig_");
try w.writeAll(operation);
try w.writeAll("o_");
try f.object.dg.renderTypeForBuiltinFnName(w, scalar_ty);
try w.writeAll("(&");
try f.writeCValueMember(w, local, .{ .identifier = "field_0" });
try f.writeCValueMember(w, local, .{ .field = 0 });
try w.writeAll(", ");
try f.writeCValue(w, lhs, .FunctionArgument);
try w.writeAll(", ");
Expand Down Expand Up @@ -3480,7 +3501,7 @@ fn airCall(
try writer.writeAll("memcpy(");
try f.writeCValue(writer, array_local, .FunctionArgument);
try writer.writeAll(", ");
try f.writeCValueMember(writer, result_local, .{ .identifier = "array" });
try f.writeCValueMember(writer, result_local, .{ .field = 0 });
try writer.writeAll(", sizeof(");
try f.renderTypecast(writer, ret_ty);
try writer.writeAll("));\n");
Expand Down Expand Up @@ -4232,16 +4253,14 @@ fn structFieldPtr(f: *Function, inst: Air.Inst.Index, struct_ptr_ty: Type, struc
try f.renderTypecast(writer, field_ptr_ty);
try writer.writeByte(')');

const extra_name: ?[]const u8 = switch (struct_ty.tag()) {
.union_tagged, .union_safety_tagged => "payload",
else => null,
const extra_name: CValue = switch (struct_ty.tag()) {
.union_tagged, .union_safety_tagged => .{ .identifier = "payload" },
else => .none,
};

var field_name_buf: []const u8 = &.{};
defer f.object.dg.gpa.free(field_name_buf);
const field_name: ?[]const u8 = switch (struct_ty.tag()) {
const field_name: CValue = switch (struct_ty.tag()) {
.@"struct" => switch (struct_ty.containerLayout()) {
.Auto, .Extern => struct_ty.structFieldName(index),
.Auto, .Extern => CValue{ .identifier = struct_ty.structFieldName(index) },
.Packed => if (field_ptr_info.data.host_size == 0) {
const target = f.object.dg.module.getTarget();

Expand All @@ -4262,29 +4281,35 @@ fn structFieldPtr(f: *Function, inst: Air.Inst.Index, struct_ptr_ty: Type, struc
try f.writeCValue(writer, struct_ptr, .Other);
try writer.print(")[{}];\n", .{try f.fmtIntLiteral(Type.usize, byte_offset_val)});
return local;
} else null,
} else @as(CValue, CValue.none), // this @as is needed because of a stage1 bug
},
.@"union", .union_safety_tagged, .union_tagged => struct_ty.unionFields().keys()[index],
.tuple, .anon_struct => |tag| field_name: {
.@"union", .union_safety_tagged, .union_tagged => .{
.identifier = struct_ty.unionFields().keys()[index],
},
.tuple, .anon_struct => field_name: {
const tuple = struct_ty.tupleFields();
if (tuple.values[index].tag() != .unreachable_value) return CValue.none;

if (tag == .anon_struct) break :field_name struct_ty.structFieldName(index);

field_name_buf = try std.fmt.allocPrint(f.object.dg.gpa, "field_{d}", .{index});
break :field_name field_name_buf;
var id: usize = 0;
for (tuple.values[0..index]) |value|
id += @boolToInt(value.tag() == .unreachable_value);
break :field_name .{ .field = id };
},
else => unreachable,
};

if (field_ty.hasRuntimeBitsIgnoreComptime()) {
try writer.writeByte('&');
if (extra_name orelse field_name) |name|
try f.writeCValueDerefMember(writer, struct_ptr, .{ .identifier = name })
if (extra_name != .none) {
try f.writeCValueDerefMember(writer, struct_ptr, extra_name);
if (field_name != .none) {
try writer.writeByte('.');
try f.writeCValue(writer, field_name, .Other);
}
} else if (field_name != .none)
try f.writeCValueDerefMember(writer, struct_ptr, field_name)
else
try f.writeCValueDeref(writer, struct_ptr);
if (extra_name) |_| if (field_name) |name|
try writer.print(".{ }", .{fmtIdent(name)});
} else try f.writeCValue(writer, struct_ptr, .Other);
try writer.writeAll(";\n");
return local;
Expand All @@ -4307,11 +4332,14 @@ fn airStructFieldVal(f: *Function, inst: Air.Inst.Index) !CValue {
// Ensure complete type definition is visible before accessing fields.
try f.renderType(std.io.null_writer, struct_ty);

var field_name_buf: []const u8 = "";
defer f.object.dg.gpa.free(field_name_buf);
const field_name = switch (struct_ty.tag()) {
const extra_name: CValue = switch (struct_ty.tag()) {
.union_tagged, .union_safety_tagged => .{ .identifier = "payload" },
else => .none,
};

const field_name: CValue = switch (struct_ty.tag()) {
.@"struct" => switch (struct_ty.containerLayout()) {
.Auto, .Extern => struct_ty.structFieldName(extra.field_index),
.Auto, .Extern => .{ .identifier = struct_ty.structFieldName(extra.field_index) },
.Packed => {
const struct_obj = struct_ty.castTag(.@"struct").?.data;
const int_info = struct_ty.intInfo(target);
Expand Down Expand Up @@ -4369,19 +4397,20 @@ fn airStructFieldVal(f: *Function, inst: Air.Inst.Index) !CValue {
return local;
},
},
.@"union", .union_safety_tagged, .union_tagged => struct_ty.unionFields().keys()[extra.field_index],
.tuple, .anon_struct => |tag| blk: {
.@"union", .union_safety_tagged, .union_tagged => .{
.identifier = struct_ty.unionFields().keys()[extra.field_index],
},
.tuple, .anon_struct => blk: {
const tuple = struct_ty.tupleFields();
if (tuple.values[extra.field_index].tag() != .unreachable_value) return CValue.none;

if (tag == .anon_struct) break :blk struct_ty.structFieldName(extra.field_index);

field_name_buf = try std.fmt.allocPrint(f.object.dg.gpa, "field_{d}", .{extra.field_index});
break :blk field_name_buf;
var id: usize = 0;
for (tuple.values[0..extra.field_index]) |value|
id += @boolToInt(value.tag() == .unreachable_value);
break :blk .{ .field = id };
},
else => unreachable,
};
const payload = if (struct_ty.tag() == .union_tagged or struct_ty.tag() == .union_safety_tagged) "payload." else "";

const is_array = lowersToArray(inst_ty, target);
const local = try f.allocLocal(inst_ty, if (is_array) .Mut else .Const);
Expand All @@ -4390,15 +4419,18 @@ fn airStructFieldVal(f: *Function, inst: Air.Inst.Index) !CValue {
try writer.writeAll("memcpy(");
try f.writeCValue(writer, local, .FunctionArgument);
try writer.writeAll(", ");
try f.writeCValue(writer, struct_byval, .Other);
try writer.print(".{s}{ }, sizeof(", .{ payload, fmtIdent(field_name) });
} else try writer.writeAll(" = ");
if (extra_name != .none) {
try f.writeCValueMember(writer, struct_byval, extra_name);
try writer.writeByte('.');
try f.writeCValue(writer, field_name, .Other);
} else try f.writeCValueMember(writer, struct_byval, field_name);
if (is_array) {
try writer.writeAll(", sizeof(");
try f.renderTypecast(writer, inst_ty);
try writer.writeAll("));\n");
} else {
try writer.writeAll(" = ");
try f.writeCValue(writer, struct_byval, .Other);
try writer.print(".{s}{ };\n", .{ payload, fmtIdent(field_name) });
try writer.writeAll("))");
}
try writer.writeAll(";\n");
return local;
}

Expand Down Expand Up @@ -5180,27 +5212,28 @@ fn airAggregateInit(f: *Function, inst: Air.Inst.Index) !CValue {
if (empty) try writer.print("{}", .{try f.fmtIntLiteral(Type.u8, Value.zero)});
try writer.writeAll("};\n");

var field_id: usize = 0;
for (elements) |element, index| {
if (inst_ty.structFieldValueComptime(index)) |_| continue;

const element_ty = f.air.typeOf(element);
if (element_ty.zigTypeTag() != .Array) continue;

var field_name_buf: []u8 = &.{};
defer f.object.dg.gpa.free(field_name_buf);
const field_name = if (inst_ty.isTuple()) field_name: {
field_name_buf = try std.fmt.allocPrint(f.object.dg.gpa, "field_{d}", .{index});
break :field_name field_name_buf;
} else inst_ty.structFieldName(index);
const field_name = if (inst_ty.isTupleOrAnonStruct())
CValue{ .field = field_id }
else
CValue{ .identifier = inst_ty.structFieldName(index) };

try writer.writeAll(";\n");
try writer.writeAll("memcpy(");
try f.writeCValue(writer, local, .Other);
try writer.print(".{ }, ", .{fmtIdent(field_name)});
try f.writeCValueMember(writer, local, field_name);
try writer.writeAll(", ");
try f.writeCValue(writer, try f.resolveInst(element), .FunctionArgument);
try writer.writeAll(", sizeof(");
try f.renderTypecast(writer, element_ty);
try writer.writeAll("));\n");

field_id += 1;
}
},
.Packed => {
Expand Down Expand Up @@ -5746,10 +5779,9 @@ fn isByRef(ty: Type) bool {
}

const LowerFnRetTyBuffer = struct {
const names = [1][]const u8{"array"};
types: [1]Type,
values: [1]Value,
payload: Type.Payload.AnonStruct,
payload: Type.Payload.Tuple,
};
fn lowerFnRetTy(ret_ty: Type, buffer: *LowerFnRetTyBuffer, target: std.Target) Type {
if (ret_ty.zigTypeTag() == .NoReturn) return Type.initTag(.noreturn);
Expand All @@ -5758,7 +5790,6 @@ fn lowerFnRetTy(ret_ty: Type, buffer: *LowerFnRetTyBuffer, target: std.Target) T
buffer.types = [1]Type{ret_ty};
buffer.values = [1]Value{Value.initTag(.unreachable_value)};
buffer.payload = .{ .data = .{
.names = &LowerFnRetTyBuffer.names,
.types = &buffer.types,
.values = &buffer.values,
} };
Expand Down
1 change: 0 additions & 1 deletion test/behavior/type.zig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -260,7 +260,6 @@ test "Type.ErrorSet" {

test "Type.Struct" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
Expand Down

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