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add @fieldParentPtr builtin function

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closes #320
This commit is contained in:
Andrew Kelley 2017-04-18 02:28:05 -04:00
parent 407916cd2f
commit a791417552
10 changed files with 295 additions and 21 deletions
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4
doc/langref.md
View File

@ -630,3 +630,7 @@ Converts an integer to a pointer. To convert the other way, use `usize(ptr)`.
### @enumTagName(value: var) -> []const u8
Converts an enum tag name to a slice of bytes. Example:
### @fieldParentPtr(comptime ParentType: type, comptime field_name: []const u8, field_ptr: &T) -> &ParentType
Given a pointer to a field, returns the base pointer of a struct.

11
src/all_types.hpp
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@ -1189,6 +1189,7 @@ enum BuiltinFnId {
BuiltinFnIdPtrCast,
BuiltinFnIdIntToPtr,
BuiltinFnIdEnumTagName,
BuiltinFnIdFieldParentPtr,
};
struct BuiltinFnEntry {
@ -1736,6 +1737,7 @@ enum IrInstructionId {
IrInstructionIdPanic,
IrInstructionIdEnumTagName,
IrInstructionIdSetFnRefInline,
IrInstructionIdFieldParentPtr,
};
struct IrInstruction {
@ -2488,6 +2490,15 @@ struct IrInstructionSetFnRefInline {
IrInstruction *fn_ref;
};
struct IrInstructionFieldParentPtr {
IrInstruction base;
IrInstruction *type_value;
IrInstruction *field_name;
IrInstruction *field_ptr;
TypeStructField *field;
};
static const size_t slice_ptr_index = 0;
static const size_t slice_len_index = 1;

31
src/codegen.cpp
View File

@ -2261,6 +2261,34 @@ static LLVMValueRef ir_render_enum_tag_name(CodeGen *g, IrExecutable *executable
return LLVMBuildInBoundsGEP(g->builder, enum_tag_type->data.enum_tag.name_table, indices, 2, "");
}
static LLVMValueRef ir_render_field_parent_ptr(CodeGen *g, IrExecutable *executable,
IrInstructionFieldParentPtr *instruction)
{
TypeTableEntry *container_ptr_type = instruction->base.value.type;
assert(container_ptr_type->id == TypeTableEntryIdPointer);
TypeTableEntry *container_type = container_ptr_type->data.pointer.child_type;
size_t byte_offset = LLVMOffsetOfElement(g->target_data_ref,
container_type->type_ref, instruction->field->gen_index);
LLVMValueRef field_ptr_val = ir_llvm_value(g, instruction->field_ptr);
if (byte_offset == 0) {
return LLVMBuildBitCast(g->builder, field_ptr_val, container_ptr_type->type_ref, "");
} else {
TypeTableEntry *usize = g->builtin_types.entry_usize;
LLVMValueRef field_ptr_int = LLVMBuildPtrToInt(g->builder, field_ptr_val,
usize->type_ref, "");
LLVMValueRef base_ptr_int = LLVMBuildNUWSub(g->builder, field_ptr_int,
LLVMConstInt(usize->type_ref, byte_offset, false), "");
return LLVMBuildIntToPtr(g->builder, base_ptr_int, container_ptr_type->type_ref, "");
}
}
static LLVMAtomicOrdering to_LLVMAtomicOrdering(AtomicOrder atomic_order) {
switch (atomic_order) {
@ -2963,6 +2991,8 @@ static LLVMValueRef ir_render_instruction(CodeGen *g, IrExecutable *executable,
return ir_render_panic(g, executable, (IrInstructionPanic *)instruction);
case IrInstructionIdEnumTagName:
return ir_render_enum_tag_name(g, executable, (IrInstructionEnumTagName *)instruction);
case IrInstructionIdFieldParentPtr:
return ir_render_field_parent_ptr(g, executable, (IrInstructionFieldParentPtr *)instruction);
}
zig_unreachable();
}
@ -4509,6 +4539,7 @@ static void define_builtin_fns(CodeGen *g) {
create_builtin_fn(g, BuiltinFnIdPtrCast, "ptrcast", 2);
create_builtin_fn(g, BuiltinFnIdIntToPtr, "intToPtr", 2);
create_builtin_fn(g, BuiltinFnIdEnumTagName, "enumTagName", 1);
create_builtin_fn(g, BuiltinFnIdFieldParentPtr, "fieldParentPtr", 3);
}
static void add_compile_var(CodeGen *g, const char *name, ConstExprValue *value) {

137
src/ir.cpp
View File

@ -549,6 +549,10 @@ static constexpr IrInstructionId ir_instruction_id(IrInstructionSetFnRefInline *
return IrInstructionIdSetFnRefInline;
}
static constexpr IrInstructionId ir_instruction_id(IrInstructionFieldParentPtr *) {
return IrInstructionIdFieldParentPtr;
}
template<typename T>
static T *ir_create_instruction(IrBuilder *irb, Scope *scope, AstNode *source_node) {
T *special_instruction = allocate<T>(1);
@ -2162,6 +2166,23 @@ static IrInstruction *ir_build_set_fn_ref_inline(IrBuilder *irb, Scope *scope, A
return &instruction->base;
}
static IrInstruction *ir_build_field_parent_ptr(IrBuilder *irb, Scope *scope, AstNode *source_node,
IrInstruction *type_value, IrInstruction *field_name, IrInstruction *field_ptr, TypeStructField *field)
{
IrInstructionFieldParentPtr *instruction = ir_build_instruction<IrInstructionFieldParentPtr>(
irb, scope, source_node);
instruction->type_value = type_value;
instruction->field_name = field_name;
instruction->field_ptr = field_ptr;
instruction->field = field;
ir_ref_instruction(type_value, irb->current_basic_block);
ir_ref_instruction(field_name, irb->current_basic_block);
ir_ref_instruction(field_ptr, irb->current_basic_block);
return &instruction->base;
}
static IrInstruction *ir_instruction_br_get_dep(IrInstructionBr *instruction, size_t index) {
return nullptr;
}
@ -2833,6 +2854,15 @@ static IrInstruction *ir_instruction_setfnrefinline_get_dep(IrInstructionSetFnRe
}
}
static IrInstruction *ir_instruction_fieldparentptr_get_dep(IrInstructionFieldParentPtr *instruction, size_t index) {
switch (index) {
case 0: return instruction->type_value;
case 1: return instruction->field_name;
case 2: return instruction->field_ptr;
default: return nullptr;
}
}
static IrInstruction *ir_instruction_get_dep(IrInstruction *instruction, size_t index) {
switch (instruction->id) {
@ -3026,6 +3056,8 @@ static IrInstruction *ir_instruction_get_dep(IrInstruction *instruction, size_t
return ir_instruction_enumtagname_get_dep((IrInstructionEnumTagName *) instruction, index);
case IrInstructionIdSetFnRefInline:
return ir_instruction_setfnrefinline_get_dep((IrInstructionSetFnRefInline *) instruction, index);
case IrInstructionIdFieldParentPtr:
return ir_instruction_fieldparentptr_get_dep((IrInstructionFieldParentPtr *) instruction, index);
}
zig_unreachable();
}
@ -4333,6 +4365,25 @@ static IrInstruction *ir_gen_builtin_fn_call(IrBuilder *irb, Scope *scope, AstNo
IrInstruction *actual_tag = ir_build_enum_tag(irb, scope, node, arg0_value);
return ir_build_enum_tag_name(irb, scope, node, actual_tag);
}
case BuiltinFnIdFieldParentPtr:
{
AstNode *arg0_node = node->data.fn_call_expr.params.at(0);
IrInstruction *arg0_value = ir_gen_node(irb, arg0_node, scope);
if (arg0_value == irb->codegen->invalid_instruction)
return arg0_value;
AstNode *arg1_node = node->data.fn_call_expr.params.at(1);
IrInstruction *arg1_value = ir_gen_node(irb, arg1_node, scope);
if (arg1_value == irb->codegen->invalid_instruction)
return arg1_value;
AstNode *arg2_node = node->data.fn_call_expr.params.at(2);
IrInstruction *arg2_value = ir_gen_node(irb, arg2_node, scope);
if (arg2_value == irb->codegen->invalid_instruction)
return arg2_value;
return ir_build_field_parent_ptr(irb, scope, node, arg0_value, arg1_value, arg2_value, nullptr);
}
}
zig_unreachable();
}
@ -11263,6 +11314,89 @@ static TypeTableEntry *ir_analyze_instruction_set_fn_ref_inline(IrAnalyze *ira,
}
}
static TypeTableEntry *ir_analyze_instruction_field_parent_ptr(IrAnalyze *ira,
IrInstructionFieldParentPtr *instruction)
{
IrInstruction *type_value = instruction->type_value->other;
TypeTableEntry *container_type = ir_resolve_type(ira, type_value);
if (type_is_invalid(container_type))
return ira->codegen->builtin_types.entry_invalid;
IrInstruction *field_name_value = instruction->field_name->other;
Buf *field_name = ir_resolve_str(ira, field_name_value);
if (!field_name)
return ira->codegen->builtin_types.entry_invalid;
IrInstruction *field_ptr = instruction->field_ptr->other;
if (type_is_invalid(field_ptr->value.type))
return ira->codegen->builtin_types.entry_invalid;
if (container_type->id != TypeTableEntryIdStruct) {
ir_add_error(ira, type_value,
buf_sprintf("expected struct type, found '%s'", buf_ptr(&container_type->name)));
return ira->codegen->builtin_types.entry_invalid;
}
ensure_complete_type(ira->codegen, container_type);
TypeStructField *field = find_struct_type_field(container_type, field_name);
if (field == nullptr) {
ir_add_error(ira, field_name_value,
buf_sprintf("struct '%s' has no field '%s'",
buf_ptr(&container_type->name), buf_ptr(field_name)));
return ira->codegen->builtin_types.entry_invalid;
}
if (field_ptr->value.type->id != TypeTableEntryIdPointer) {
ir_add_error(ira, field_ptr,
buf_sprintf("expected pointer, found '%s'", buf_ptr(&field_ptr->value.type->name)));
return ira->codegen->builtin_types.entry_invalid;
}
TypeTableEntry *field_ptr_type = get_pointer_to_type_extra(ira->codegen, field->type_entry,
field_ptr->value.type->data.pointer.is_const,
field_ptr->value.type->data.pointer.is_volatile, 0, 0);
IrInstruction *casted_field_ptr = ir_implicit_cast(ira, field_ptr, field_ptr_type);
if (type_is_invalid(casted_field_ptr->value.type))
return ira->codegen->builtin_types.entry_invalid;
TypeTableEntry *result_type = get_pointer_to_type_extra(ira->codegen, container_type,
casted_field_ptr->value.type->data.pointer.is_const,
casted_field_ptr->value.type->data.pointer.is_volatile, 0, 0);
if (instr_is_comptime(casted_field_ptr)) {
ConstExprValue *field_ptr_val = ir_resolve_const(ira, casted_field_ptr, UndefBad);
if (!field_ptr_val)
return ira->codegen->builtin_types.entry_invalid;
if (field_ptr_val->data.x_ptr.special != ConstPtrSpecialBaseStruct) {
ir_add_error(ira, field_ptr, buf_sprintf("pointer value not based on parent struct"));
return ira->codegen->builtin_types.entry_invalid;
}
size_t ptr_field_index = field_ptr_val->data.x_ptr.data.base_struct.field_index;
if (ptr_field_index != field->src_index) {
ir_add_error(ira, &instruction->base,
buf_sprintf("field '%s' has index %zu but pointer value is index %zu of struct '%s'",
buf_ptr(field->name), field->src_index,
ptr_field_index, buf_ptr(&container_type->name)));
return ira->codegen->builtin_types.entry_invalid;
}
ConstExprValue *out_val = ir_build_const_from(ira, &instruction->base);
out_val->data.x_ptr.special = ConstPtrSpecialRef;
out_val->data.x_ptr.data.ref.pointee = field_ptr_val->data.x_ptr.data.base_struct.struct_val;
out_val->data.x_ptr.mut = field_ptr_val->data.x_ptr.mut;
return result_type;
}
IrInstruction *result = ir_build_field_parent_ptr(&ira->new_irb, instruction->base.scope,
instruction->base.source_node, type_value, field_name_value, casted_field_ptr, field);
ir_link_new_instruction(result, &instruction->base);
return result_type;
}
static TypeTableEntry *ir_analyze_instruction_type_name(IrAnalyze *ira, IrInstructionTypeName *instruction) {
IrInstruction *type_value = instruction->type_value->other;
TypeTableEntry *type_entry = ir_resolve_type(ira, type_value);
@ -12781,6 +12915,8 @@ static TypeTableEntry *ir_analyze_instruction_nocast(IrAnalyze *ira, IrInstructi
return ir_analyze_instruction_enum_tag_name(ira, (IrInstructionEnumTagName *)instruction);
case IrInstructionIdSetFnRefInline:
return ir_analyze_instruction_set_fn_ref_inline(ira, (IrInstructionSetFnRefInline *)instruction);
case IrInstructionIdFieldParentPtr:
return ir_analyze_instruction_field_parent_ptr(ira, (IrInstructionFieldParentPtr *)instruction);
case IrInstructionIdMaybeWrap:
case IrInstructionIdErrWrapCode:
case IrInstructionIdErrWrapPayload:
@ -12964,6 +13100,7 @@ bool ir_has_side_effects(IrInstruction *instruction) {
case IrInstructionIdTypeName:
case IrInstructionIdEnumTagName:
case IrInstructionIdSetFnRefInline:
case IrInstructionIdFieldParentPtr:
return false;
case IrInstructionIdAsm:
{

13
src/ir_print.cpp
View File

@ -875,6 +875,16 @@ static void ir_print_set_fn_ref_inline(IrPrint *irp, IrInstructionSetFnRefInline
ir_print_other_instruction(irp, instruction->fn_ref);
}
static void ir_print_field_parent_ptr(IrPrint *irp, IrInstructionFieldParentPtr *instruction) {
fprintf(irp->f, "@fieldParentPtr(");
ir_print_other_instruction(irp, instruction->type_value);
fprintf(irp->f, ",");
ir_print_other_instruction(irp, instruction->field_name);
fprintf(irp->f, ",");
ir_print_other_instruction(irp, instruction->field_ptr);
fprintf(irp->f, ")");
}
static void ir_print_instruction(IrPrint *irp, IrInstruction *instruction) {
ir_print_prefix(irp, instruction);
switch (instruction->id) {
@ -1162,6 +1172,9 @@ static void ir_print_instruction(IrPrint *irp, IrInstruction *instruction) {
case IrInstructionIdSetFnRefInline:
ir_print_set_fn_ref_inline(irp, (IrInstructionSetFnRefInline *)instruction);
break;
case IrInstructionIdFieldParentPtr:
ir_print_field_parent_ptr(irp, (IrInstructionFieldParentPtr *)instruction);
break;
}
fprintf(irp->f, "\n");
}

24
std/build.zig
View File

@ -580,9 +580,7 @@ const Exe = struct {
}
fn make(step: &Step) -> %void {
// TODO issue #320
//const self = @fieldParentPtr(Exe, "step", step);
const exe = @ptrcast(&Exe, step);
const exe = @fieldParentPtr(Exe, "step", step);
const builder = exe.builder;
var zig_args = List([]const u8).init(builder.allocator);
@ -754,9 +752,7 @@ const CLibrary = struct {
}
fn make(step: &Step) -> %void {
// TODO issue #320
//const self = @fieldParentPtr(CLibrary, "step", step);
const self = @ptrcast(&CLibrary, step);
const self = @fieldParentPtr(CLibrary, "step", step);
const cc = os.getEnv("CC") ?? "cc";
const builder = self.builder;
@ -897,9 +893,7 @@ const CExecutable = struct {
}
fn make(step: &Step) -> %void {
// TODO issue #320
//const self = @fieldParentPtr(CExecutable, "step", step);
const self = @ptrcast(&CExecutable, step);
const self = @fieldParentPtr(CExecutable, "step", step);
const cc = os.getEnv("CC") ?? "cc";
const builder = self.builder;
@ -987,9 +981,7 @@ const CommandStep = struct {
}
fn make(step: &Step) -> %void {
// TODO issue #320
//const self = @fieldParentPtr(CExecutable, "step", step);
const self = @ptrcast(&CommandStep, step);
const self = @fieldParentPtr(CommandStep, "step", step);
// TODO set cwd
self.builder.spawnChildEnvMap(self.env_map, self.exe_path, self.args);
@ -1021,9 +1013,7 @@ const InstallCLibraryStep = struct {
}
fn make(step: &Step) -> %void {
// TODO issue #320
//const self = @fieldParentPtr(InstallCLibraryStep, "step", step);
const self = @ptrcast(&InstallCLibraryStep, step);
const self = @fieldParentPtr(InstallCLibraryStep, "step", step);
self.builder.copyFile(self.lib.out_filename, self.dest_file);
if (!self.lib.static) {
@ -1051,9 +1041,7 @@ const InstallFileStep = struct {
}
fn make(step: &Step) -> %void {
// TODO issue #320
//const self = @fieldParentPtr(InstallFileStep, "step", step);
const self = @ptrcast(&InstallFileStep, step);
const self = @fieldParentPtr(InstallFileStep, "step", step);
debug.panic("TODO install file");
}

4
std/mem.zig
View File

@ -76,9 +76,7 @@ pub const IncrementingAllocator = struct {
}
fn alloc(allocator: &Allocator, n: usize) -> %[]u8 {
// TODO issue #320
//const self = @fieldParentPtr(IncrementingAllocator, "allocator", allocator);
const self = @ptrcast(&IncrementingAllocator, allocator);
const self = @fieldParentPtr(IncrementingAllocator, "allocator", allocator);
const new_end_index = self.end_index + n;
if (new_end_index > self.bytes.len) {
return error.NoMem;

41
test/cases/field_parent_ptr.zig Normal file
View File

@ -0,0 +1,41 @@
const assert = @import("std").debug.assert;
test "@fieldParentPtr non-first field" {
testParentFieldPtr(&foo.c);
comptime testParentFieldPtr(&foo.c);
}
test "@fieldParentPtr first field" {
testParentFieldPtrFirst(&foo.a);
comptime testParentFieldPtrFirst(&foo.a);
}
const Foo = struct {
a: bool,
b: f32,
c: i32,
d: i32,
};
const foo = Foo {
.a = true,
.b = 0.123,
.c = 1234,
.d = -10,
};
fn testParentFieldPtr(c: &const i32) {
assert(c == &foo.c);
const base = @fieldParentPtr(Foo, "c", c);
assert(base == &foo);
assert(&base.c == c);
}
fn testParentFieldPtrFirst(a: &const bool) {
assert(a == &foo.a);
const base = @fieldParentPtr(Foo, "a", a);
assert(base == &foo);
assert(&base.a == a);
}

50
test/run_tests.cpp
View File

@ -1902,6 +1902,56 @@ export fn foo() {
var y: &void = @intToPtr(&void, x);
}
)SOURCE", 1, ".tmp_source.zig:4:31: error: type '&void' has 0 bits and cannot store information");
add_compile_fail_case("@fieldParentPtr - non struct", R"SOURCE(
const Foo = i32;
export fn foo(a: &i32) -> &Foo {
return @fieldParentPtr(Foo, "a", a);
}
)SOURCE", 1, ".tmp_source.zig:4:28: error: expected struct type, found 'i32'");
add_compile_fail_case("@fieldParentPtr - bad field name", R"SOURCE(
const Foo = struct {
derp: i32,
};
export fn foo(a: &i32) -> &Foo {
return @fieldParentPtr(Foo, "a", a);
}
)SOURCE", 1, ".tmp_source.zig:6:33: error: struct 'Foo' has no field 'a'");
add_compile_fail_case("@fieldParentPtr - field pointer is not pointer", R"SOURCE(
const Foo = struct {
a: i32,
};
export fn foo(a: i32) -> &Foo {
return @fieldParentPtr(Foo, "a", a);
}
)SOURCE", 1, ".tmp_source.zig:6:38: error: expected pointer, found 'i32'");
add_compile_fail_case("@fieldParentPtr - comptime field ptr not based on struct", R"SOURCE(
const Foo = struct {
a: i32,
b: i32,
};
const foo = Foo { .a = 1, .b = 2, };
comptime {
const field_ptr = @intToPtr(&i32, 0x1234);
const another_foo_ptr = @fieldParentPtr(Foo, "b", field_ptr);
}
)SOURCE", 1, ".tmp_source.zig:10:55: error: pointer value not based on parent struct");
add_compile_fail_case("@fieldParentPtr - comptime wrong field index", R"SOURCE(
const Foo = struct {
a: i32,
b: i32,
};
const foo = Foo { .a = 1, .b = 2, };
comptime {
const another_foo_ptr = @fieldParentPtr(Foo, "b", &foo.a);
}
)SOURCE", 1, ".tmp_source.zig:9:29: error: field 'b' has index 1 but pointer value is index 0 of struct 'Foo'");
}
//////////////////////////////////////////////////////////////////////////////

1
test/self_hosted.zig
View File

@ -10,6 +10,7 @@ comptime {
_ = @import("cases/enum_with_members.zig");
_ = @import("cases/error.zig");
_ = @import("cases/eval.zig");
_ = @import("cases/field_parent_ptr.zig");
_ = @import("cases/fn.zig");
_ = @import("cases/for.zig");
_ = @import("cases/generics.zig");