zig/src-self-hosted/value.zig

980 lines
33 KiB
Zig

const std = @import("std");
const Type = @import("type.zig").Type;
const log2 = std.math.log2;
const assert = std.debug.assert;
const BigIntConst = std.math.big.int.Const;
const BigIntMutable = std.math.big.int.Mutable;
const Target = std.Target;
const Allocator = std.mem.Allocator;
const Module = @import("Module.zig");
/// This is the raw data, with no bookkeeping, no memory awareness,
/// no de-duplication, and no type system awareness.
/// It's important for this type to be small.
/// This union takes advantage of the fact that the first page of memory
/// is unmapped, giving us 4096 possible enum tags that have no payload.
pub const Value = extern union {
/// If the tag value is less than Tag.no_payload_count, then no pointer
/// dereference is needed.
tag_if_small_enough: usize,
ptr_otherwise: *Payload,
pub const Tag = enum {
// The first section of this enum are tags that require no payload.
u8_type,
i8_type,
isize_type,
usize_type,
c_short_type,
c_ushort_type,
c_int_type,
c_uint_type,
c_long_type,
c_ulong_type,
c_longlong_type,
c_ulonglong_type,
c_longdouble_type,
f16_type,
f32_type,
f64_type,
f128_type,
c_void_type,
bool_type,
void_type,
type_type,
anyerror_type,
comptime_int_type,
comptime_float_type,
noreturn_type,
null_type,
undefined_type,
fn_noreturn_no_args_type,
fn_naked_noreturn_no_args_type,
fn_ccc_void_no_args_type,
single_const_pointer_to_comptime_int_type,
const_slice_u8_type,
undef,
zero,
the_one_possible_value, // when the type only has one possible value
null_value,
bool_true,
bool_false, // See last_no_payload_tag below.
// After this, the tag requires a payload.
ty,
int_u64,
int_i64,
int_big_positive,
int_big_negative,
function,
ref_val,
decl_ref,
elem_ptr,
bytes,
repeated, // the value is a value repeated some number of times
pub const last_no_payload_tag = Tag.bool_false;
pub const no_payload_count = @enumToInt(last_no_payload_tag) + 1;
};
pub fn initTag(comptime small_tag: Tag) Value {
comptime assert(@enumToInt(small_tag) < Tag.no_payload_count);
return .{ .tag_if_small_enough = @enumToInt(small_tag) };
}
pub fn initPayload(payload: *Payload) Value {
assert(@enumToInt(payload.tag) >= Tag.no_payload_count);
return .{ .ptr_otherwise = payload };
}
pub fn tag(self: Value) Tag {
if (self.tag_if_small_enough < Tag.no_payload_count) {
return @intToEnum(Tag, @intCast(@TagType(Tag), self.tag_if_small_enough));
} else {
return self.ptr_otherwise.tag;
}
}
pub fn cast(self: Value, comptime T: type) ?*T {
if (self.tag_if_small_enough < Tag.no_payload_count)
return null;
const expected_tag = std.meta.fieldInfo(T, "base").default_value.?.tag;
if (self.ptr_otherwise.tag != expected_tag)
return null;
return @fieldParentPtr(T, "base", self.ptr_otherwise);
}
pub fn format(
self: Value,
comptime fmt: []const u8,
options: std.fmt.FormatOptions,
out_stream: var,
) !void {
comptime assert(fmt.len == 0);
var val = self;
while (true) switch (val.tag()) {
.u8_type => return out_stream.writeAll("u8"),
.i8_type => return out_stream.writeAll("i8"),
.isize_type => return out_stream.writeAll("isize"),
.usize_type => return out_stream.writeAll("usize"),
.c_short_type => return out_stream.writeAll("c_short"),
.c_ushort_type => return out_stream.writeAll("c_ushort"),
.c_int_type => return out_stream.writeAll("c_int"),
.c_uint_type => return out_stream.writeAll("c_uint"),
.c_long_type => return out_stream.writeAll("c_long"),
.c_ulong_type => return out_stream.writeAll("c_ulong"),
.c_longlong_type => return out_stream.writeAll("c_longlong"),
.c_ulonglong_type => return out_stream.writeAll("c_ulonglong"),
.c_longdouble_type => return out_stream.writeAll("c_longdouble"),
.f16_type => return out_stream.writeAll("f16"),
.f32_type => return out_stream.writeAll("f32"),
.f64_type => return out_stream.writeAll("f64"),
.f128_type => return out_stream.writeAll("f128"),
.c_void_type => return out_stream.writeAll("c_void"),
.bool_type => return out_stream.writeAll("bool"),
.void_type => return out_stream.writeAll("void"),
.type_type => return out_stream.writeAll("type"),
.anyerror_type => return out_stream.writeAll("anyerror"),
.comptime_int_type => return out_stream.writeAll("comptime_int"),
.comptime_float_type => return out_stream.writeAll("comptime_float"),
.noreturn_type => return out_stream.writeAll("noreturn"),
.null_type => return out_stream.writeAll("@TypeOf(null)"),
.undefined_type => return out_stream.writeAll("@TypeOf(undefined)"),
.fn_noreturn_no_args_type => return out_stream.writeAll("fn() noreturn"),
.fn_naked_noreturn_no_args_type => return out_stream.writeAll("fn() callconv(.Naked) noreturn"),
.fn_ccc_void_no_args_type => return out_stream.writeAll("fn() callconv(.C) void"),
.single_const_pointer_to_comptime_int_type => return out_stream.writeAll("*const comptime_int"),
.const_slice_u8_type => return out_stream.writeAll("[]const u8"),
.null_value => return out_stream.writeAll("null"),
.undef => return out_stream.writeAll("undefined"),
.zero => return out_stream.writeAll("0"),
.the_one_possible_value => return out_stream.writeAll("(one possible value)"),
.bool_true => return out_stream.writeAll("true"),
.bool_false => return out_stream.writeAll("false"),
.ty => return val.cast(Payload.Ty).?.ty.format("", options, out_stream),
.int_u64 => return std.fmt.formatIntValue(val.cast(Payload.Int_u64).?.int, "", options, out_stream),
.int_i64 => return std.fmt.formatIntValue(val.cast(Payload.Int_i64).?.int, "", options, out_stream),
.int_big_positive => return out_stream.print("{}", .{val.cast(Payload.IntBigPositive).?.asBigInt()}),
.int_big_negative => return out_stream.print("{}", .{val.cast(Payload.IntBigNegative).?.asBigInt()}),
.function => return out_stream.writeAll("(function)"),
.ref_val => {
const ref_val = val.cast(Payload.RefVal).?;
try out_stream.writeAll("&const ");
val = ref_val.val;
},
.decl_ref => return out_stream.writeAll("(decl ref)"),
.elem_ptr => {
const elem_ptr = val.cast(Payload.ElemPtr).?;
try out_stream.print("&[{}] ", .{elem_ptr.index});
val = elem_ptr.array_ptr;
},
.bytes => return std.zig.renderStringLiteral(self.cast(Payload.Bytes).?.data, out_stream),
.repeated => {
try out_stream.writeAll("(repeated) ");
val = val.cast(Payload.Repeated).?.val;
},
};
}
/// Asserts that the value is representable as an array of bytes.
/// Copies the value into a freshly allocated slice of memory, which is owned by the caller.
pub fn toAllocatedBytes(self: Value, allocator: *Allocator) ![]u8 {
if (self.cast(Payload.Bytes)) |bytes| {
return std.mem.dupe(allocator, u8, bytes.data);
}
if (self.cast(Payload.Repeated)) |repeated| {
@panic("TODO implement toAllocatedBytes for this Value tag");
}
if (self.cast(Payload.DeclRef)) |declref| {
const val = try declref.decl.value();
return val.toAllocatedBytes(allocator);
}
unreachable;
}
/// Asserts that the value is representable as a type.
pub fn toType(self: Value) Type {
return switch (self.tag()) {
.ty => self.cast(Payload.Ty).?.ty,
.u8_type => Type.initTag(.u8),
.i8_type => Type.initTag(.i8),
.isize_type => Type.initTag(.isize),
.usize_type => Type.initTag(.usize),
.c_short_type => Type.initTag(.c_short),
.c_ushort_type => Type.initTag(.c_ushort),
.c_int_type => Type.initTag(.c_int),
.c_uint_type => Type.initTag(.c_uint),
.c_long_type => Type.initTag(.c_long),
.c_ulong_type => Type.initTag(.c_ulong),
.c_longlong_type => Type.initTag(.c_longlong),
.c_ulonglong_type => Type.initTag(.c_ulonglong),
.c_longdouble_type => Type.initTag(.c_longdouble),
.f16_type => Type.initTag(.f16),
.f32_type => Type.initTag(.f32),
.f64_type => Type.initTag(.f64),
.f128_type => Type.initTag(.f128),
.c_void_type => Type.initTag(.c_void),
.bool_type => Type.initTag(.bool),
.void_type => Type.initTag(.void),
.type_type => Type.initTag(.type),
.anyerror_type => Type.initTag(.anyerror),
.comptime_int_type => Type.initTag(.comptime_int),
.comptime_float_type => Type.initTag(.comptime_float),
.noreturn_type => Type.initTag(.noreturn),
.null_type => Type.initTag(.@"null"),
.undefined_type => Type.initTag(.@"undefined"),
.fn_noreturn_no_args_type => Type.initTag(.fn_noreturn_no_args),
.fn_naked_noreturn_no_args_type => Type.initTag(.fn_naked_noreturn_no_args),
.fn_ccc_void_no_args_type => Type.initTag(.fn_ccc_void_no_args),
.single_const_pointer_to_comptime_int_type => Type.initTag(.single_const_pointer_to_comptime_int),
.const_slice_u8_type => Type.initTag(.const_slice_u8),
.undef,
.zero,
.the_one_possible_value,
.bool_true,
.bool_false,
.null_value,
.int_u64,
.int_i64,
.int_big_positive,
.int_big_negative,
.function,
.ref_val,
.decl_ref,
.elem_ptr,
.bytes,
.repeated,
=> unreachable,
};
}
/// Asserts the value is an integer.
pub fn toBigInt(self: Value, space: *BigIntSpace) BigIntConst {
switch (self.tag()) {
.ty,
.u8_type,
.i8_type,
.isize_type,
.usize_type,
.c_short_type,
.c_ushort_type,
.c_int_type,
.c_uint_type,
.c_long_type,
.c_ulong_type,
.c_longlong_type,
.c_ulonglong_type,
.c_longdouble_type,
.f16_type,
.f32_type,
.f64_type,
.f128_type,
.c_void_type,
.bool_type,
.void_type,
.type_type,
.anyerror_type,
.comptime_int_type,
.comptime_float_type,
.noreturn_type,
.null_type,
.undefined_type,
.fn_noreturn_no_args_type,
.fn_naked_noreturn_no_args_type,
.fn_ccc_void_no_args_type,
.single_const_pointer_to_comptime_int_type,
.const_slice_u8_type,
.bool_true,
.bool_false,
.null_value,
.function,
.ref_val,
.decl_ref,
.elem_ptr,
.bytes,
.undef,
.repeated,
=> unreachable,
.the_one_possible_value, // An integer with one possible value is always zero.
.zero,
=> return BigIntMutable.init(&space.limbs, 0).toConst(),
.int_u64 => return BigIntMutable.init(&space.limbs, self.cast(Payload.Int_u64).?.int).toConst(),
.int_i64 => return BigIntMutable.init(&space.limbs, self.cast(Payload.Int_i64).?.int).toConst(),
.int_big_positive => return self.cast(Payload.IntBigPositive).?.asBigInt(),
.int_big_negative => return self.cast(Payload.IntBigPositive).?.asBigInt(),
}
}
/// Asserts the value is an integer and it fits in a u64
pub fn toUnsignedInt(self: Value) u64 {
switch (self.tag()) {
.ty,
.u8_type,
.i8_type,
.isize_type,
.usize_type,
.c_short_type,
.c_ushort_type,
.c_int_type,
.c_uint_type,
.c_long_type,
.c_ulong_type,
.c_longlong_type,
.c_ulonglong_type,
.c_longdouble_type,
.f16_type,
.f32_type,
.f64_type,
.f128_type,
.c_void_type,
.bool_type,
.void_type,
.type_type,
.anyerror_type,
.comptime_int_type,
.comptime_float_type,
.noreturn_type,
.null_type,
.undefined_type,
.fn_noreturn_no_args_type,
.fn_naked_noreturn_no_args_type,
.fn_ccc_void_no_args_type,
.single_const_pointer_to_comptime_int_type,
.const_slice_u8_type,
.bool_true,
.bool_false,
.null_value,
.function,
.ref_val,
.decl_ref,
.elem_ptr,
.bytes,
.undef,
.repeated,
=> unreachable,
.zero,
.the_one_possible_value, // an integer with one possible value is always zero
=> return 0,
.int_u64 => return self.cast(Payload.Int_u64).?.int,
.int_i64 => return @intCast(u64, self.cast(Payload.Int_u64).?.int),
.int_big_positive => return self.cast(Payload.IntBigPositive).?.asBigInt().to(u64) catch unreachable,
.int_big_negative => return self.cast(Payload.IntBigNegative).?.asBigInt().to(u64) catch unreachable,
}
}
/// Asserts the value is an integer and not undefined.
/// Returns the number of bits the value requires to represent stored in twos complement form.
pub fn intBitCountTwosComp(self: Value) usize {
switch (self.tag()) {
.ty,
.u8_type,
.i8_type,
.isize_type,
.usize_type,
.c_short_type,
.c_ushort_type,
.c_int_type,
.c_uint_type,
.c_long_type,
.c_ulong_type,
.c_longlong_type,
.c_ulonglong_type,
.c_longdouble_type,
.f16_type,
.f32_type,
.f64_type,
.f128_type,
.c_void_type,
.bool_type,
.void_type,
.type_type,
.anyerror_type,
.comptime_int_type,
.comptime_float_type,
.noreturn_type,
.null_type,
.undefined_type,
.fn_noreturn_no_args_type,
.fn_naked_noreturn_no_args_type,
.fn_ccc_void_no_args_type,
.single_const_pointer_to_comptime_int_type,
.const_slice_u8_type,
.bool_true,
.bool_false,
.null_value,
.function,
.ref_val,
.decl_ref,
.elem_ptr,
.bytes,
.undef,
.repeated,
=> unreachable,
.the_one_possible_value, // an integer with one possible value is always zero
.zero,
=> return 0,
.int_u64 => {
const x = self.cast(Payload.Int_u64).?.int;
if (x == 0) return 0;
return std.math.log2(x) + 1;
},
.int_i64 => {
@panic("TODO implement i64 intBitCountTwosComp");
},
.int_big_positive => return self.cast(Payload.IntBigPositive).?.asBigInt().bitCountTwosComp(),
.int_big_negative => return self.cast(Payload.IntBigNegative).?.asBigInt().bitCountTwosComp(),
}
}
/// Asserts the value is an integer, and the destination type is ComptimeInt or Int.
pub fn intFitsInType(self: Value, ty: Type, target: Target) bool {
switch (self.tag()) {
.ty,
.u8_type,
.i8_type,
.isize_type,
.usize_type,
.c_short_type,
.c_ushort_type,
.c_int_type,
.c_uint_type,
.c_long_type,
.c_ulong_type,
.c_longlong_type,
.c_ulonglong_type,
.c_longdouble_type,
.f16_type,
.f32_type,
.f64_type,
.f128_type,
.c_void_type,
.bool_type,
.void_type,
.type_type,
.anyerror_type,
.comptime_int_type,
.comptime_float_type,
.noreturn_type,
.null_type,
.undefined_type,
.fn_noreturn_no_args_type,
.fn_naked_noreturn_no_args_type,
.fn_ccc_void_no_args_type,
.single_const_pointer_to_comptime_int_type,
.const_slice_u8_type,
.bool_true,
.bool_false,
.null_value,
.function,
.ref_val,
.decl_ref,
.elem_ptr,
.bytes,
.repeated,
=> unreachable,
.zero,
.undef,
.the_one_possible_value, // an integer with one possible value is always zero
=> return true,
.int_u64 => switch (ty.zigTypeTag()) {
.Int => {
const x = self.cast(Payload.Int_u64).?.int;
if (x == 0) return true;
const info = ty.intInfo(target);
const needed_bits = std.math.log2(x) + 1 + @boolToInt(info.signed);
return info.bits >= needed_bits;
},
.ComptimeInt => return true,
else => unreachable,
},
.int_i64 => switch (ty.zigTypeTag()) {
.Int => {
const x = self.cast(Payload.Int_i64).?.int;
if (x == 0) return true;
const info = ty.intInfo(target);
if (!info.signed and x < 0)
return false;
@panic("TODO implement i64 intFitsInType");
},
.ComptimeInt => return true,
else => unreachable,
},
.int_big_positive => switch (ty.zigTypeTag()) {
.Int => {
const info = ty.intInfo(target);
return self.cast(Payload.IntBigPositive).?.asBigInt().fitsInTwosComp(info.signed, info.bits);
},
.ComptimeInt => return true,
else => unreachable,
},
.int_big_negative => switch (ty.zigTypeTag()) {
.Int => {
const info = ty.intInfo(target);
return self.cast(Payload.IntBigNegative).?.asBigInt().fitsInTwosComp(info.signed, info.bits);
},
.ComptimeInt => return true,
else => unreachable,
},
}
}
/// Asserts the value is a float
pub fn floatHasFraction(self: Value) bool {
return switch (self.tag()) {
.ty,
.u8_type,
.i8_type,
.isize_type,
.usize_type,
.c_short_type,
.c_ushort_type,
.c_int_type,
.c_uint_type,
.c_long_type,
.c_ulong_type,
.c_longlong_type,
.c_ulonglong_type,
.c_longdouble_type,
.f16_type,
.f32_type,
.f64_type,
.f128_type,
.c_void_type,
.bool_type,
.void_type,
.type_type,
.anyerror_type,
.comptime_int_type,
.comptime_float_type,
.noreturn_type,
.null_type,
.undefined_type,
.fn_noreturn_no_args_type,
.fn_naked_noreturn_no_args_type,
.fn_ccc_void_no_args_type,
.single_const_pointer_to_comptime_int_type,
.const_slice_u8_type,
.bool_true,
.bool_false,
.null_value,
.function,
.ref_val,
.decl_ref,
.elem_ptr,
.bytes,
.repeated,
.undef,
.int_u64,
.int_i64,
.int_big_positive,
.int_big_negative,
.the_one_possible_value,
=> unreachable,
.zero => false,
};
}
pub fn orderAgainstZero(lhs: Value) std.math.Order {
switch (lhs.tag()) {
.ty,
.u8_type,
.i8_type,
.isize_type,
.usize_type,
.c_short_type,
.c_ushort_type,
.c_int_type,
.c_uint_type,
.c_long_type,
.c_ulong_type,
.c_longlong_type,
.c_ulonglong_type,
.c_longdouble_type,
.f16_type,
.f32_type,
.f64_type,
.f128_type,
.c_void_type,
.bool_type,
.void_type,
.type_type,
.anyerror_type,
.comptime_int_type,
.comptime_float_type,
.noreturn_type,
.null_type,
.undefined_type,
.fn_noreturn_no_args_type,
.fn_naked_noreturn_no_args_type,
.fn_ccc_void_no_args_type,
.single_const_pointer_to_comptime_int_type,
.const_slice_u8_type,
.bool_true,
.bool_false,
.null_value,
.function,
.ref_val,
.decl_ref,
.elem_ptr,
.bytes,
.repeated,
.undef,
=> unreachable,
.zero,
.the_one_possible_value, // an integer with one possible value is always zero
=> return .eq,
.int_u64 => return std.math.order(lhs.cast(Payload.Int_u64).?.int, 0),
.int_i64 => return std.math.order(lhs.cast(Payload.Int_i64).?.int, 0),
.int_big_positive => return lhs.cast(Payload.IntBigPositive).?.asBigInt().orderAgainstScalar(0),
.int_big_negative => return lhs.cast(Payload.IntBigNegative).?.asBigInt().orderAgainstScalar(0),
}
}
/// Asserts the value is comparable.
pub fn order(lhs: Value, rhs: Value) std.math.Order {
const lhs_tag = lhs.tag();
const rhs_tag = lhs.tag();
const lhs_is_zero = lhs_tag == .zero or lhs_tag == .the_one_possible_value;
const rhs_is_zero = rhs_tag == .zero or rhs_tag == .the_one_possible_value;
if (lhs_is_zero) return rhs.orderAgainstZero().invert();
if (rhs_is_zero) return lhs.orderAgainstZero();
// TODO floats
var lhs_bigint_space: BigIntSpace = undefined;
var rhs_bigint_space: BigIntSpace = undefined;
const lhs_bigint = lhs.toBigInt(&lhs_bigint_space);
const rhs_bigint = rhs.toBigInt(&rhs_bigint_space);
return lhs_bigint.order(rhs_bigint);
}
/// Asserts the value is comparable.
pub fn compare(lhs: Value, op: std.math.CompareOperator, rhs: Value) bool {
return order(lhs, rhs).compare(op);
}
/// Asserts the value is comparable.
pub fn compareWithZero(lhs: Value, op: std.math.CompareOperator) bool {
return orderAgainstZero(lhs).compare(op);
}
pub fn eql(a: Value, b: Value) bool {
// TODO non numerical comparisons
return compare(a, .eq, b);
}
pub fn toBool(self: Value) bool {
return switch (self.tag()) {
.bool_true => true,
.bool_false => false,
else => unreachable,
};
}
/// Asserts the value is a pointer and dereferences it.
/// Returns error.AnalysisFail if the pointer points to a Decl that failed semantic analysis.
pub fn pointerDeref(self: Value, allocator: *Allocator) error{ AnalysisFail, OutOfMemory }!Value {
return switch (self.tag()) {
.ty,
.u8_type,
.i8_type,
.isize_type,
.usize_type,
.c_short_type,
.c_ushort_type,
.c_int_type,
.c_uint_type,
.c_long_type,
.c_ulong_type,
.c_longlong_type,
.c_ulonglong_type,
.c_longdouble_type,
.f16_type,
.f32_type,
.f64_type,
.f128_type,
.c_void_type,
.bool_type,
.void_type,
.type_type,
.anyerror_type,
.comptime_int_type,
.comptime_float_type,
.noreturn_type,
.null_type,
.undefined_type,
.fn_noreturn_no_args_type,
.fn_naked_noreturn_no_args_type,
.fn_ccc_void_no_args_type,
.single_const_pointer_to_comptime_int_type,
.const_slice_u8_type,
.zero,
.bool_true,
.bool_false,
.null_value,
.function,
.int_u64,
.int_i64,
.int_big_positive,
.int_big_negative,
.bytes,
.undef,
.repeated,
=> unreachable,
.the_one_possible_value => Value.initTag(.the_one_possible_value),
.ref_val => self.cast(Payload.RefVal).?.val,
.decl_ref => self.cast(Payload.DeclRef).?.decl.value(),
.elem_ptr => {
const elem_ptr = self.cast(Payload.ElemPtr).?;
const array_val = try elem_ptr.array_ptr.pointerDeref(allocator);
return array_val.elemValue(allocator, elem_ptr.index);
},
};
}
/// Asserts the value is a single-item pointer to an array, or an array,
/// or an unknown-length pointer, and returns the element value at the index.
pub fn elemValue(self: Value, allocator: *Allocator, index: usize) error{OutOfMemory}!Value {
switch (self.tag()) {
.ty,
.u8_type,
.i8_type,
.isize_type,
.usize_type,
.c_short_type,
.c_ushort_type,
.c_int_type,
.c_uint_type,
.c_long_type,
.c_ulong_type,
.c_longlong_type,
.c_ulonglong_type,
.c_longdouble_type,
.f16_type,
.f32_type,
.f64_type,
.f128_type,
.c_void_type,
.bool_type,
.void_type,
.type_type,
.anyerror_type,
.comptime_int_type,
.comptime_float_type,
.noreturn_type,
.null_type,
.undefined_type,
.fn_noreturn_no_args_type,
.fn_naked_noreturn_no_args_type,
.fn_ccc_void_no_args_type,
.single_const_pointer_to_comptime_int_type,
.const_slice_u8_type,
.zero,
.the_one_possible_value,
.bool_true,
.bool_false,
.null_value,
.function,
.int_u64,
.int_i64,
.int_big_positive,
.int_big_negative,
.undef,
.elem_ptr,
.ref_val,
.decl_ref,
=> unreachable,
.bytes => {
const int_payload = try allocator.create(Payload.Int_u64);
int_payload.* = .{ .int = self.cast(Payload.Bytes).?.data[index] };
return Value.initPayload(&int_payload.base);
},
// No matter the index; all the elements are the same!
.repeated => return self.cast(Payload.Repeated).?.val,
}
}
/// Returns a pointer to the element value at the index.
pub fn elemPtr(self: Value, allocator: *Allocator, index: usize) !Value {
const payload = try allocator.create(Payload.ElemPtr);
if (self.cast(Payload.ElemPtr)) |elem_ptr| {
payload.* = .{ .array_ptr = elem_ptr.array_ptr, .index = elem_ptr.index + index };
} else {
payload.* = .{ .array_ptr = self, .index = index };
}
return Value.initPayload(&payload.base);
}
pub fn isUndef(self: Value) bool {
return self.tag() == .undef;
}
/// Valid for all types. Asserts the value is not undefined.
/// `.the_one_possible_value` is reported as not null.
pub fn isNull(self: Value) bool {
return switch (self.tag()) {
.ty,
.u8_type,
.i8_type,
.isize_type,
.usize_type,
.c_short_type,
.c_ushort_type,
.c_int_type,
.c_uint_type,
.c_long_type,
.c_ulong_type,
.c_longlong_type,
.c_ulonglong_type,
.c_longdouble_type,
.f16_type,
.f32_type,
.f64_type,
.f128_type,
.c_void_type,
.bool_type,
.void_type,
.type_type,
.anyerror_type,
.comptime_int_type,
.comptime_float_type,
.noreturn_type,
.null_type,
.undefined_type,
.fn_noreturn_no_args_type,
.fn_naked_noreturn_no_args_type,
.fn_ccc_void_no_args_type,
.single_const_pointer_to_comptime_int_type,
.const_slice_u8_type,
.zero,
.the_one_possible_value,
.bool_true,
.bool_false,
.function,
.int_u64,
.int_i64,
.int_big_positive,
.int_big_negative,
.ref_val,
.decl_ref,
.elem_ptr,
.bytes,
.repeated,
=> false,
.undef => unreachable,
.null_value => true,
};
}
/// This type is not copyable since it may contain pointers to its inner data.
pub const Payload = struct {
tag: Tag,
pub const Int_u64 = struct {
base: Payload = Payload{ .tag = .int_u64 },
int: u64,
};
pub const Int_i64 = struct {
base: Payload = Payload{ .tag = .int_i64 },
int: i64,
};
pub const IntBigPositive = struct {
base: Payload = Payload{ .tag = .int_big_positive },
limbs: []const std.math.big.Limb,
pub fn asBigInt(self: IntBigPositive) BigIntConst {
return BigIntConst{ .limbs = self.limbs, .positive = true };
}
};
pub const IntBigNegative = struct {
base: Payload = Payload{ .tag = .int_big_negative },
limbs: []const std.math.big.Limb,
pub fn asBigInt(self: IntBigNegative) BigIntConst {
return BigIntConst{ .limbs = self.limbs, .positive = false };
}
};
pub const Function = struct {
base: Payload = Payload{ .tag = .function },
func: *Module.Fn,
};
pub const ArraySentinel0_u8_Type = struct {
base: Payload = Payload{ .tag = .array_sentinel_0_u8_type },
len: u64,
};
pub const SingleConstPtrType = struct {
base: Payload = Payload{ .tag = .single_const_ptr_type },
elem_type: *Type,
};
/// Represents a pointer to another immutable value.
pub const RefVal = struct {
base: Payload = Payload{ .tag = .ref_val },
val: Value,
};
/// Represents a pointer to a decl, not the value of the decl.
pub const DeclRef = struct {
base: Payload = Payload{ .tag = .decl_ref },
decl: *Module.Decl,
};
pub const ElemPtr = struct {
base: Payload = Payload{ .tag = .elem_ptr },
array_ptr: Value,
index: usize,
};
pub const Bytes = struct {
base: Payload = Payload{ .tag = .bytes },
data: []const u8,
};
pub const Ty = struct {
base: Payload = Payload{ .tag = .ty },
ty: Type,
};
pub const Repeated = struct {
base: Payload = Payload{ .tag = .ty },
/// This value is repeated some number of times. The amount of times to repeat
/// is stored externally.
val: Value,
};
};
/// Big enough to fit any non-BigInt value
pub const BigIntSpace = struct {
/// The +1 is headroom so that operations such as incrementing once or decrementing once
/// are possible without using an allocator.
limbs: [(@sizeOf(u64) / @sizeOf(std.math.big.Limb)) + 1]std.math.big.Limb,
};
};