authorgravatar for raulgrell@gmail.comraulgrell <raulgrell@gmail.com> 2018-09-07 22:43:01+01:00
committergravatar for raulgrell@gmail.comraulgrell <raulgrell@gmail.com> 2018-09-07 22:49:19+01:00
log09a1162af57858a9579ef112b75472f82581e1d3
tree7d955ccaf912924421807ff84ea24e0e90020da6
parentb18af37c578b118a245c911508d73ed23c303ee0

builtin functions: @byteOffsetOf and @bitOffsetOf

7 files changed, 176 insertions(+), 56 deletions(-)

doc/langref.html.in+8-2
......@@ -5838,8 +5838,14 @@ fn add(a: i32, b: i32) i32 {
58385838 </p>
58395839 {#see_also|@inlineCall#}
58405840 {#header_close#}
5841 {#header_open|@offsetOf#}
5842 <pre><code class="zig">@offsetOf(comptime T: type, comptime field_name: [] const u8) (number literal)</code></pre>
5841 {#header_open|@byteOffsetOf#}
5842 <pre><code class="zig">@byteOffsetOf(comptime T: type, comptime field_name: [] const u8) (number literal)</code></pre>
5843 <p>
5844 This function returns the byte offset of a field relative to its containing struct.
5845 </p>
5846 {#header_close#}
5847 {#header_open|@bitOffsetOf#}
5848 <pre><code class="zig">@bitOffsetOf(comptime T: type, comptime field_name: [] const u8) (number literal)</code></pre>
58435849 <p>
58445850 This function returns the byte offset of a field relative to its containing struct.
58455851 </p>
src/all_types.hpp+12-3
......@@ -1395,7 +1395,8 @@ enum BuiltinFnId {
13951395 BuiltinFnIdTagName,
13961396 BuiltinFnIdTagType,
13971397 BuiltinFnIdFieldParentPtr,
1398 BuiltinFnIdOffsetOf,
1398 BuiltinFnIdByteOffsetOf,
1399 BuiltinFnIdBitOffsetOf,
13991400 BuiltinFnIdInlineCall,
14001401 BuiltinFnIdNoInlineCall,
14011402 BuiltinFnIdNewStackCall,
......@@ -2119,7 +2120,8 @@ enum IrInstructionId {
21192120 IrInstructionIdTagName,
21202121 IrInstructionIdTagType,
21212122 IrInstructionIdFieldParentPtr,
2122 IrInstructionIdOffsetOf,
2123 IrInstructionIdByteOffsetOf,
2124 IrInstructionIdBitOffsetOf,
21232125 IrInstructionIdTypeInfo,
21242126 IrInstructionIdTypeId,
21252127 IrInstructionIdSetEvalBranchQuota,
......@@ -3022,7 +3024,14 @@ struct IrInstructionFieldParentPtr {
30223024 TypeStructField *field;
30233025};
30243026
3025struct IrInstructionOffsetOf {
3027struct IrInstructionByteOffsetOf {
3028 IrInstruction base;
3029
3030 IrInstruction *type_value;
3031 IrInstruction *field_name;
3032};
3033
3034struct IrInstructionBitOffsetOf {
30263035 IrInstruction base;
30273036
30283037 IrInstruction *type_value;
src/codegen.cpp+4-2
......@@ -5194,7 +5194,8 @@ static LLVMValueRef ir_render_instruction(CodeGen *g, IrExecutable *executable,
51945194 case IrInstructionIdTypeName:
51955195 case IrInstructionIdDeclRef:
51965196 case IrInstructionIdSwitchVar:
5197 case IrInstructionIdOffsetOf:
5197 case IrInstructionIdByteOffsetOf:
5198 case IrInstructionIdBitOffsetOf:
51985199 case IrInstructionIdTypeInfo:
51995200 case IrInstructionIdTypeId:
52005201 case IrInstructionIdSetEvalBranchQuota:
......@@ -6766,7 +6767,8 @@ static void define_builtin_fns(CodeGen *g) {
67666767 create_builtin_fn(g, BuiltinFnIdTagName, "tagName", 1);
67676768 create_builtin_fn(g, BuiltinFnIdTagType, "TagType", 1);
67686769 create_builtin_fn(g, BuiltinFnIdFieldParentPtr, "fieldParentPtr", 3);
6769 create_builtin_fn(g, BuiltinFnIdOffsetOf, "offsetOf", 2);
6770 create_builtin_fn(g, BuiltinFnIdByteOffsetOf, "byteOffsetOf", 2);
6771 create_builtin_fn(g, BuiltinFnIdBitOffsetOf, "bitOffsetOf", 2);
67706772 create_builtin_fn(g, BuiltinFnIdDivExact, "divExact", 2);
67716773 create_builtin_fn(g, BuiltinFnIdDivTrunc, "divTrunc", 2);
67726774 create_builtin_fn(g, BuiltinFnIdDivFloor, "divFloor", 2);
src/ir.cpp+91-27
......@@ -719,8 +719,12 @@ static constexpr IrInstructionId ir_instruction_id(IrInstructionFieldParentPtr *
719719 return IrInstructionIdFieldParentPtr;
720720}
721721
722static constexpr IrInstructionId ir_instruction_id(IrInstructionOffsetOf *) {
723 return IrInstructionIdOffsetOf;
722static constexpr IrInstructionId ir_instruction_id(IrInstructionByteOffsetOf *) {
723 return IrInstructionIdByteOffsetOf;
724}
725
726static constexpr IrInstructionId ir_instruction_id(IrInstructionBitOffsetOf *) {
727 return IrInstructionIdBitOffsetOf;
724728}
725729
726730static constexpr IrInstructionId ir_instruction_id(IrInstructionTypeInfo *) {
......@@ -2645,10 +2649,23 @@ static IrInstruction *ir_build_field_parent_ptr(IrBuilder *irb, Scope *scope, As
26452649 return &instruction->base;
26462650}
26472651
2648static IrInstruction *ir_build_offset_of(IrBuilder *irb, Scope *scope, AstNode *source_node,
2652static IrInstruction *ir_build_byte_offset_of(IrBuilder *irb, Scope *scope, AstNode *source_node,
2653 IrInstruction *type_value, IrInstruction *field_name)
2654{
2655 IrInstructionByteOffsetOf *instruction = ir_build_instruction<IrInstructionByteOffsetOf>(irb, scope, source_node);
2656 instruction->type_value = type_value;
2657 instruction->field_name = field_name;
2658
2659 ir_ref_instruction(type_value, irb->current_basic_block);
2660 ir_ref_instruction(field_name, irb->current_basic_block);
2661
2662 return &instruction->base;
2663}
2664
2665static IrInstruction *ir_build_bit_offset_of(IrBuilder *irb, Scope *scope, AstNode *source_node,
26492666 IrInstruction *type_value, IrInstruction *field_name)
26502667{
2651 IrInstructionOffsetOf *instruction = ir_build_instruction<IrInstructionOffsetOf>(irb, scope, source_node);
2668 IrInstructionBitOffsetOf *instruction = ir_build_instruction<IrInstructionBitOffsetOf>(irb, scope, source_node);
26522669 instruction->type_value = type_value;
26532670 instruction->field_name = field_name;
26542671
......@@ -4695,7 +4712,22 @@ static IrInstruction *ir_gen_builtin_fn_call(IrBuilder *irb, Scope *scope, AstNo
46954712 IrInstruction *field_parent_ptr = ir_build_field_parent_ptr(irb, scope, node, arg0_value, arg1_value, arg2_value, nullptr);
46964713 return ir_lval_wrap(irb, scope, field_parent_ptr, lval);
46974714 }
4698 case BuiltinFnIdOffsetOf:
4715 case BuiltinFnIdByteOffsetOf:
4716 {
4717 AstNode *arg0_node = node->data.fn_call_expr.params.at(0);
4718 IrInstruction *arg0_value = ir_gen_node(irb, arg0_node, scope);
4719 if (arg0_value == irb->codegen->invalid_instruction)
4720 return arg0_value;
4721
4722 AstNode *arg1_node = node->data.fn_call_expr.params.at(1);
4723 IrInstruction *arg1_value = ir_gen_node(irb, arg1_node, scope);
4724 if (arg1_value == irb->codegen->invalid_instruction)
4725 return arg1_value;
4726
4727 IrInstruction *offset_of = ir_build_byte_offset_of(irb, scope, node, arg0_value, arg1_value);
4728 return ir_lval_wrap(irb, scope, offset_of, lval);
4729 }
4730 case BuiltinFnIdBitOffsetOf:
46994731 {
47004732 AstNode *arg0_node = node->data.fn_call_expr.params.at(0);
47014733 IrInstruction *arg0_value = ir_gen_node(irb, arg0_node, scope);
......@@ -4707,7 +4739,7 @@ static IrInstruction *ir_gen_builtin_fn_call(IrBuilder *irb, Scope *scope, AstNo
47074739 if (arg1_value == irb->codegen->invalid_instruction)
47084740 return arg1_value;
47094741
4710 IrInstruction *offset_of = ir_build_offset_of(irb, scope, node, arg0_value, arg1_value);
4742 IrInstruction *offset_of = ir_build_bit_offset_of(irb, scope, node, arg0_value, arg1_value);
47114743 return ir_lval_wrap(irb, scope, offset_of, lval);
47124744 }
47134745 case BuiltinFnIdInlineCall:
......@@ -16909,47 +16941,76 @@ static ZigType *ir_analyze_instruction_field_parent_ptr(IrAnalyze *ira,
1690916941 return result_type;
1691016942}
1691116943
16912static ZigType *ir_analyze_instruction_offset_of(IrAnalyze *ira,
16913 IrInstructionOffsetOf *instruction)
16944static TypeStructField *validate_byte_offset(IrAnalyze *ira,
16945 IrInstruction *type_value,
16946 IrInstruction *field_name_value,
16947 size_t *byte_offset)
1691416948{
16915 Error err;
16916 IrInstruction *type_value = instruction->type_value->other;
1691716949 ZigType *container_type = ir_resolve_type(ira, type_value);
1691816950 if (type_is_invalid(container_type))
16919 return ira->codegen->builtin_types.entry_invalid;
16951 return nullptr;
1692016952
16953 Error err;
1692116954 if ((err = ensure_complete_type(ira->codegen, container_type)))
16922 return ira->codegen->builtin_types.entry_invalid;
16955 return nullptr;
1692316956
16924 IrInstruction *field_name_value = instruction->field_name->other;
1692516957 Buf *field_name = ir_resolve_str(ira, field_name_value);
1692616958 if (!field_name)
16927 return ira->codegen->builtin_types.entry_invalid;
16959 return nullptr;
1692816960
1692916961 if (container_type->id != ZigTypeIdStruct) {
1693016962 ir_add_error(ira, type_value,
1693116963 buf_sprintf("expected struct type, found '%s'", buf_ptr(&container_type->name)));
16932 return ira->codegen->builtin_types.entry_invalid;
16964 return nullptr;
1693316965 }
1693416966
1693516967 TypeStructField *field = find_struct_type_field(container_type, field_name);
1693616968 if (field == nullptr) {
1693716969 ir_add_error(ira, field_name_value,
1693816970 buf_sprintf("struct '%s' has no field '%s'",
16939 buf_ptr(&container_type->name), buf_ptr(field_name)));
16940 return ira->codegen->builtin_types.entry_invalid;
16971 buf_ptr(&container_type->name), buf_ptr(field_name)));
16972 return nullptr;
1694116973 }
1694216974
1694316975 if (!type_has_bits(field->type_entry)) {
1694416976 ir_add_error(ira, field_name_value,
16945 buf_sprintf("zero-bit field '%s' in struct '%s' has no offset",
16946 buf_ptr(field_name), buf_ptr(&container_type->name)));
16947 return ira->codegen->builtin_types.entry_invalid;
16977 buf_sprintf("zero-bit field '%s' in struct '%s' has no offset",
16978 buf_ptr(field_name), buf_ptr(&container_type->name)));
16979 return nullptr;
1694816980 }
16949 size_t byte_offset = LLVMOffsetOfElement(ira->codegen->target_data_ref, container_type->type_ref, field->gen_index);
16950 ConstExprValue *out_val = ir_build_const_from(ira, &instruction->base);
16951 bigint_init_unsigned(&out_val->data.x_bigint, byte_offset);
16952 return ira->codegen->builtin_types.entry_num_lit_int;
16981
16982 *byte_offset = LLVMOffsetOfElement(ira->codegen->target_data_ref, container_type->type_ref, field->gen_index);
16983 return field;
16984}
16985
16986static ZigType *ir_analyze_instruction_byte_offset_of(IrAnalyze *ira,
16987 IrInstructionByteOffsetOf *instruction)
16988{
16989 IrInstruction *type_value = instruction->type_value->other;
16990 IrInstruction *field_name_value = instruction->field_name->other;
16991 size_t byte_offset = 0;
16992 if (validate_byte_offset(ira, type_value, field_name_value, &byte_offset)) {
16993 ConstExprValue *out_val = ir_build_const_from(ira, &instruction->base);
16994 bigint_init_unsigned(&out_val->data.x_bigint, byte_offset);
16995 return ira->codegen->builtin_types.entry_num_lit_int;
16996 }
16997 return ira->codegen->builtin_types.entry_invalid;
16998}
16999
17000static ZigType *ir_analyze_instruction_bit_offset_of(IrAnalyze *ira,
17001 IrInstructionBitOffsetOf *instruction)
17002{
17003 IrInstruction *type_value = instruction->type_value->other;
17004 IrInstruction *field_name_value = instruction->field_name->other;
17005 size_t byte_offset = 0;
17006 TypeStructField *field = nullptr;
17007 if ((field = validate_byte_offset(ira, type_value, field_name_value, &byte_offset))) {
17008 size_t bit_offset = byte_offset * 8 + field->packed_bits_offset;
17009 ConstExprValue *out_val = ir_build_const_from(ira, &instruction->base);
17010 bigint_init_unsigned(&out_val->data.x_bigint, bit_offset);
17011 return ira->codegen->builtin_types.entry_num_lit_int;
17012 }
17013 return ira->codegen->builtin_types.entry_invalid;
1695317014}
1695417015
1695517016static void ensure_field_index(ZigType *type, const char *field_name, size_t index)
......@@ -21362,8 +21423,10 @@ static ZigType *ir_analyze_instruction_nocast(IrAnalyze *ira, IrInstruction *ins
2136221423 return ir_analyze_instruction_enum_tag_name(ira, (IrInstructionTagName *)instruction);
2136321424 case IrInstructionIdFieldParentPtr:
2136421425 return ir_analyze_instruction_field_parent_ptr(ira, (IrInstructionFieldParentPtr *)instruction);
21365 case IrInstructionIdOffsetOf:
21366 return ir_analyze_instruction_offset_of(ira, (IrInstructionOffsetOf *)instruction);
21426 case IrInstructionIdByteOffsetOf:
21427 return ir_analyze_instruction_byte_offset_of(ira, (IrInstructionByteOffsetOf *)instruction);
21428 case IrInstructionIdBitOffsetOf:
21429 return ir_analyze_instruction_bit_offset_of(ira, (IrInstructionBitOffsetOf *)instruction);
2136721430 case IrInstructionIdTypeInfo:
2136821431 return ir_analyze_instruction_type_info(ira, (IrInstructionTypeInfo *) instruction);
2136921432 case IrInstructionIdTypeId:
......@@ -21647,7 +21710,8 @@ bool ir_has_side_effects(IrInstruction *instruction) {
2164721710 case IrInstructionIdTypeName:
2164821711 case IrInstructionIdTagName:
2164921712 case IrInstructionIdFieldParentPtr:
21650 case IrInstructionIdOffsetOf:
21713 case IrInstructionIdByteOffsetOf:
21714 case IrInstructionIdBitOffsetOf:
2165121715 case IrInstructionIdTypeInfo:
2165221716 case IrInstructionIdTypeId:
2165321717 case IrInstructionIdAlignCast:
src/ir_print.cpp+15-4
......@@ -1041,8 +1041,16 @@ static void ir_print_field_parent_ptr(IrPrint *irp, IrInstructionFieldParentPtr
10411041 fprintf(irp->f, ")");
10421042}
10431043
1044static void ir_print_offset_of(IrPrint *irp, IrInstructionOffsetOf *instruction) {
1045 fprintf(irp->f, "@offset_of(");
1044static void ir_print_byte_offset_of(IrPrint *irp, IrInstructionByteOffsetOf *instruction) {
1045 fprintf(irp->f, "@byte_offset_of(");
1046 ir_print_other_instruction(irp, instruction->type_value);
1047 fprintf(irp->f, ",");
1048 ir_print_other_instruction(irp, instruction->field_name);
1049 fprintf(irp->f, ")");
1050}
1051
1052static void ir_print_bit_offset_of(IrPrint *irp, IrInstructionBitOffsetOf *instruction) {
1053 fprintf(irp->f, "@bit_offset_of(");
10461054 ir_print_other_instruction(irp, instruction->type_value);
10471055 fprintf(irp->f, ",");
10481056 ir_print_other_instruction(irp, instruction->field_name);
......@@ -1649,8 +1657,11 @@ static void ir_print_instruction(IrPrint *irp, IrInstruction *instruction) {
16491657 case IrInstructionIdFieldParentPtr:
16501658 ir_print_field_parent_ptr(irp, (IrInstructionFieldParentPtr *)instruction);
16511659 break;
1652 case IrInstructionIdOffsetOf:
1653 ir_print_offset_of(irp, (IrInstructionOffsetOf *)instruction);
1660 case IrInstructionIdByteOffsetOf:
1661 ir_print_byte_offset_of(irp, (IrInstructionByteOffsetOf *)instruction);
1662 break;
1663 case IrInstructionIdBitOffsetOf:
1664 ir_print_bit_offset_of(irp, (IrInstructionBitOffsetOf *)instruction);
16541665 break;
16551666 case IrInstructionIdTypeInfo:
16561667 ir_print_type_info(irp, (IrInstructionTypeInfo *)instruction);
test/cases/sizeof_and_typeof.zig+28-12
......@@ -7,28 +7,44 @@ test "sizeofAndTypeOf" {
77const x: u16 = 13;
88const z: @typeOf(x) = 19;
99
10const A = struct {
10const S = struct {
1111 a: u8,
1212 b: u32,
1313 c: u8,
14 d: u3,
15 e: u5,
16 f: u16,
17 g: u16,
1418};
1519
1620const P = packed struct {
1721 a: u8,
1822 b: u32,
1923 c: u8,
24 d: u3,
25 e: u5,
26 f: u16,
27 g: u16,
2028};
2129
22test "offsetOf" {
23 // Packed structs have fixed memory layout
30test "byteOffsetOf" {
2431 const p: P = undefined;
25 assert(@offsetOf(P, "a") == 0);
26 assert(@offsetOf(@typeOf(p), "b") == 1);
27 assert(@offsetOf(@typeOf(p), "c") == 5);
28
29 // Non-packed struct fields can be moved/padded
30 const a: A = undefined;
31 assert(@ptrToInt(&a.a) - @ptrToInt(&a) == @offsetOf(A, "a"));
32 assert(@ptrToInt(&a.b) - @ptrToInt(&a) == @offsetOf(@typeOf(a), "b"));
33 assert(@ptrToInt(&a.c) - @ptrToInt(&a) == @offsetOf(@typeOf(a), "c"));
32 std.debug.assert(@byteOffsetOf(P, "a") == 0 and @byteOffsetOf(S, "a") == 0);
33 std.debug.assert(@byteOffsetOf(P, "b") == 1 and @byteOffsetOf(S, "b") == 4);
34 std.debug.assert(@byteOffsetOf(P, "c") == 5 and @byteOffsetOf(S, "c") == 8);
35 std.debug.assert(@byteOffsetOf(P, "d") == 6 and @byteOffsetOf(S, "d") == 9);
36 std.debug.assert(@byteOffsetOf(P, "e") == 6 and @byteOffsetOf(S, "e") == 10);
37 std.debug.assert(@byteOffsetOf(P, "f") == 7 and @byteOffsetOf(S, "f") == 12);
38 std.debug.assert(@byteOffsetOf(P, "g") == 9 and @byteOffsetOf(S, "g") == 14);
3439}
40
41test "bitOffsetOf" {
42 const p: P = undefined;
43 std.debug.assert(@bitOffsetOf(P, "a") == 0 and @bitOffsetOf(S, "a") == 0);
44 std.debug.assert(@bitOffsetOf(P, "b") == 8 and @bitOffsetOf(S, "b") == 32);
45 std.debug.assert(@bitOffsetOf(P, "c") == 40 and @bitOffsetOf(S, "c") == 64);
46 std.debug.assert(@bitOffsetOf(P, "d") == 48 and @bitOffsetOf(S, "d") == 72);
47 std.debug.assert(@bitOffsetOf(P, "e") == 51 and @bitOffsetOf(S, "e") == 80);
48 std.debug.assert(@bitOffsetOf(P, "f") == 56 and @bitOffsetOf(S, "f") == 96);
49 std.debug.assert(@bitOffsetOf(P, "g") == 72 and @bitOffsetOf(S, "g") == 112);
50}
\ No newline at end of file
test/compile_errors.zig+18-6
......@@ -3706,22 +3706,22 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
37063706 );
37073707
37083708 cases.add(
3709 "@offsetOf - non struct",
3709 "@byteOffsetOf - non struct",
37103710 \\const Foo = i32;
37113711 \\export fn foo() usize {
3712 \\ return @offsetOf(Foo, "a",);
3712 \\ return @byteOffsetOf(Foo, "a",);
37133713 \\}
37143714 ,
37153715 ".tmp_source.zig:3:22: error: expected struct type, found 'i32'",
37163716 );
37173717
37183718 cases.add(
3719 "@offsetOf - bad field name",
3719 "@byteOffsetOf - bad field name",
37203720 \\const Foo = struct {
37213721 \\ derp: i32,
37223722 \\};
37233723 \\export fn foo() usize {
3724 \\ return @offsetOf(Foo, "a",);
3724 \\ return @byteOffsetOf(Foo, "a",);
37253725 \\}
37263726 ,
37273727 ".tmp_source.zig:5:27: error: struct 'Foo' has no field 'a'",
......@@ -5029,12 +5029,24 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
50295029 );
50305030
50315031 cases.add(
5032 "taking offset of void field in struct",
5032 "taking byte offset of void field in struct",
50335033 \\const Empty = struct {
50345034 \\ val: void,
50355035 \\};
50365036 \\export fn foo() void {
5037 \\ const fieldOffset = @offsetOf(Empty, "val",);
5037 \\ const fieldOffset = @byteOffsetOf(Empty, "val",);
5038 \\}
5039 ,
5040 ".tmp_source.zig:5:42: error: zero-bit field 'val' in struct 'Empty' has no offset",
5041 );
5042
5043 cases.add(
5044 "taking bit offset of void field in struct",
5045 \\const Empty = struct {
5046 \\ val: void,
5047 \\};
5048 \\export fn foo() void {
5049 \\ const fieldOffset = @bitOffsetOf(Empty, "val",);
50385050 \\}
50395051 ,
50405052 ".tmp_source.zig:5:42: error: zero-bit field 'val' in struct 'Empty' has no offset",