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//! An "interner" is a data structure that associates values with usize tags and
//! allows bidirectional lookup; i.e., given a value, one can easily find the
//! type, and vice versa.
use rustc_arena::DroplessArena;
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
use rustc_data_structures::sync::Lock;
use rustc_macros::HashStable_Generic;
use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
use std::fmt;
use std::hash::{Hash, Hasher};
use std::str;
use crate::{with_session_globals, Edition, Span, DUMMY_SP};
#[cfg(test)]
mod tests;
// The proc macro code for this is in `compiler/rustc_macros/src/symbols.rs`.
symbols! {
// After modifying this list adjust `is_special`, `is_used_keyword`/`is_unused_keyword`,
// this should be rarely necessary though if the keywords are kept in alphabetic order.
Keywords {
// Special reserved identifiers used internally for elided lifetimes,
// unnamed method parameters, crate root module, error recovery etc.
Empty: "",
PathRoot: "{{root}}",
DollarCrate: "$crate",
Underscore: "_",
// Keywords that are used in stable Rust.
As: "as",
Break: "break",
Const: "const",
Continue: "continue",
Crate: "crate",
Else: "else",
Enum: "enum",
Extern: "extern",
False: "false",
Fn: "fn",
For: "for",
If: "if",
Impl: "impl",
In: "in",
Let: "let",
Loop: "loop",
Match: "match",
Mod: "mod",
Move: "move",
Mut: "mut",
Pub: "pub",
Ref: "ref",
Return: "return",
SelfLower: "self",
SelfUpper: "Self",
Static: "static",
Struct: "struct",
Super: "super",
Trait: "trait",
True: "true",
Type: "type",
Unsafe: "unsafe",
Use: "use",
Where: "where",
While: "while",
// Keywords that are used in unstable Rust or reserved for future use.
Abstract: "abstract",
Become: "become",
Box: "box",
Do: "do",
Final: "final",
Macro: "macro",
Override: "override",
Priv: "priv",
Typeof: "typeof",
Unsized: "unsized",
Virtual: "virtual",
Yield: "yield",
// Edition-specific keywords that are used in stable Rust.
Async: "async", // >= 2018 Edition only
Await: "await", // >= 2018 Edition only
Dyn: "dyn", // >= 2018 Edition only
// Edition-specific keywords that are used in unstable Rust or reserved for future use.
Try: "try", // >= 2018 Edition only
// Special lifetime names
UnderscoreLifetime: "'_",
StaticLifetime: "'static",
// Weak keywords, have special meaning only in specific contexts.
Auto: "auto",
Builtin: "builtin",
Catch: "catch",
Default: "default",
MacroRules: "macro_rules",
Raw: "raw",
Union: "union",
Yeet: "yeet",
}
// Pre-interned symbols that can be referred to with `rustc_span::sym::*`.
//
// The symbol is the stringified identifier unless otherwise specified, in
// which case the name should mention the non-identifier punctuation.
// E.g. `sym::proc_dash_macro` represents "proc-macro", and it shouldn't be
// called `sym::proc_macro` because then it's easy to mistakenly think it
// represents "proc_macro".
//
// As well as the symbols listed, there are symbols for the strings
// "0", "1", ..., "9", which are accessible via `sym::integer`.
//
// The proc macro will abort if symbols are not in alphabetical order (as
// defined by `impl Ord for str`) or if any symbols are duplicated. Vim
// users can sort the list by selecting it and executing the command
// `:'<,'>!LC_ALL=C sort`.
//
// There is currently no checking that all symbols are used; that would be
// nice to have.
Symbols {
AcqRel,
Acquire,
AddToDiagnostic,
Alignment,
Any,
Arc,
Argument,
ArgumentMethods,
Arguments,
AsMut,
AsRef,
AssertParamIsClone,
AssertParamIsCopy,
AssertParamIsEq,
AtomicBool,
AtomicI128,
AtomicI16,
AtomicI32,
AtomicI64,
AtomicI8,
AtomicIsize,
AtomicPtr,
AtomicU128,
AtomicU16,
AtomicU32,
AtomicU64,
AtomicU8,
AtomicUsize,
BTreeEntry,
BTreeMap,
BTreeSet,
BinaryHeap,
Borrow,
BorrowMut,
Break,
C,
CStr,
CString,
Capture,
Center,
Clone,
ConstParamTy,
Context,
Continue,
Copy,
Count,
Cow,
Debug,
Decodable,
Decoder,
DecorateLint,
Default,
Deref,
DiagnosticMessage,
DirBuilder,
Display,
DoubleEndedIterator,
Duration,
Encodable,
Encoder,
Eq,
Equal,
Err,
Error,
File,
FileType,
FormatSpec,
Formatter,
From,
FromIterator,
FromResidual,
Future,
FutureOutput,
FxHashMap,
FxHashSet,
GlobalAlloc,
Hash,
HashMap,
HashMapEntry,
HashSet,
Hasher,
Implied,
IndexOutput,
Input,
Into,
IntoDiagnostic,
IntoFuture,
IntoIterator,
IoRead,
IoWrite,
IpAddr,
IrTyKind,
Is,
ItemContext,
Iterator,
IteratorItem,
Layout,
Left,
LinkedList,
LintPass,
LocalKey,
Mutex,
MutexGuard,
N,
NonZeroI128,
NonZeroI16,
NonZeroI32,
NonZeroI64,
NonZeroI8,
NonZeroU128,
NonZeroU16,
NonZeroU32,
NonZeroU64,
NonZeroU8,
None,
Ok,
Option,
Ord,
Ordering,
OsStr,
OsString,
Output,
Param,
PartialEq,
PartialOrd,
Path,
PathBuf,
Pending,
Pin,
Pointer,
Poll,
ProcMacro,
ProceduralMasqueradeDummyType,
Range,
RangeFrom,
RangeFull,
RangeInclusive,
RangeTo,
RangeToInclusive,
Rc,
Ready,
Receiver,
RefCell,
Relaxed,
Release,
Result,
ResumeTy,
Return,
Right,
Rust,
RustcDecodable,
RustcEncodable,
RwLock,
RwLockReadGuard,
RwLockWriteGuard,
Send,
SeqCst,
SliceIndex,
Some,
String,
StructuralEq,
StructuralPartialEq,
SubdiagnosticMessage,
Sync,
T,
Target,
ToOwned,
ToString,
TokenStream,
Try,
TryCaptureGeneric,
TryCapturePrintable,
TryFrom,
TryInto,
Ty,
TyCtxt,
TyKind,
Unknown,
UnsafeArg,
Vec,
VecDeque,
Wrapper,
Yield,
_DECLS,
_Self,
__D,
__H,
__S,
__awaitee,
__try_var,
_d,
_e,
_task_context,
a32,
aarch64_target_feature,
aarch64_ver_target_feature,
abi,
abi_amdgpu_kernel,
abi_avr_interrupt,
abi_c_cmse_nonsecure_call,
abi_efiapi,
abi_msp430_interrupt,
abi_ptx,
abi_riscv_interrupt,
abi_sysv64,
abi_thiscall,
abi_unadjusted,
abi_vectorcall,
abi_x86_interrupt,
abort,
add,
add_assign,
add_with_overflow,
address,
adt_const_params,
advanced_slice_patterns,
adx_target_feature,
alias,
align,
align_offset,
alignment,
all,
alloc,
alloc_error_handler,
alloc_layout,
alloc_zeroed,
allocator,
allocator_api,
allocator_internals,
allow,
allow_fail,
allow_internal_unsafe,
allow_internal_unstable,
allowed,
alu32,
always,
and,
and_then,
anon,
anonymous_lifetime_in_impl_trait,
any,
append_const_msg,
arbitrary_enum_discriminant,
arbitrary_self_types,
args,
arith_offset,
arm,
arm_target_feature,
array,
arrays,
as_mut_ptr,
as_ptr,
as_ref,
as_str,
asm,
asm_const,
asm_experimental_arch,
asm_sym,
asm_unwind,
assert,
assert_eq_macro,
assert_inhabited,
assert_macro,
assert_mem_uninitialized_valid,
assert_ne_macro,
assert_receiver_is_total_eq,
assert_zero_valid,
asserting,
associated_const_equality,
associated_consts,
associated_type_bounds,
associated_type_defaults,
associated_types,
assume,
assume_init,
async_await,
async_closure,
async_fn_in_trait,
async_fn_track_caller,
atomic,
atomic_mod,
atomics,
att_syntax,
attr,
attr_literals,
attributes,
augmented_assignments,
auto_traits,
automatically_derived,
avx,
avx512_target_feature,
avx512bw,
avx512f,
await_macro,
bang,
begin_panic,
bench,
bin,
bind_by_move_pattern_guards,
bindings_after_at,
bitand,
bitand_assign,
bitor,
bitor_assign,
bitreverse,
bitxor,
bitxor_assign,
black_box,
block,
bool,
borrowck_graphviz_format,
borrowck_graphviz_postflow,
box_new,
box_patterns,
box_syntax,
bpf_target_feature,
braced_empty_structs,
branch,
breakpoint,
bridge,
bswap,
builtin_syntax,
c,
c_str,
c_str_literals,
c_unwind,
c_variadic,
c_void,
call,
call_mut,
call_once,
caller_location,
capture_disjoint_fields,
cause,
cdylib,
ceilf32,
ceilf64,
cfg,
cfg_accessible,
cfg_attr,
cfg_attr_multi,
cfg_doctest,
cfg_eval,
cfg_hide,
cfg_overflow_checks,
cfg_panic,
cfg_relocation_model,
cfg_sanitize,
cfg_target_abi,
cfg_target_compact,
cfg_target_feature,
cfg_target_has_atomic,
cfg_target_has_atomic_equal_alignment,
cfg_target_thread_local,
cfg_target_vendor,
cfg_version,
cfi,
cfi_encoding,
char,
client,
clippy,
clobber_abi,
clone,
clone_closures,
clone_from,
closure,
closure_lifetime_binder,
closure_to_fn_coercion,
closure_track_caller,
cmp,
cmp_max,
cmp_min,
cmpxchg16b_target_feature,
cmse_nonsecure_entry,
coerce_unsized,
cold,
collapse_debuginfo,
column,
compare_bytes,
compare_exchange,
compare_exchange_weak,
compile_error,
compiler,
compiler_builtins,
compiler_fence,
concat,
concat_bytes,
concat_idents,
conservative_impl_trait,
console,
const_allocate,
const_async_blocks,
const_closures,
const_compare_raw_pointers,
const_constructor,
const_deallocate,
const_eval_limit,
const_eval_select,
const_evaluatable_checked,
const_extern_fn,
const_fn,
const_fn_floating_point_arithmetic,
const_fn_fn_ptr_basics,
const_fn_trait_bound,
const_fn_transmute,
const_fn_union,
const_fn_unsize,
const_for,
const_format_args,
const_generics,
const_generics_defaults,
const_if_match,
const_impl_trait,
const_in_array_repeat_expressions,
const_indexing,
const_let,
const_loop,
const_mut_refs,
const_panic,
const_panic_fmt,
const_param_ty,
const_precise_live_drops,
const_ptr_cast,
const_raw_ptr_deref,
const_raw_ptr_to_usize_cast,
const_refs_to_cell,
const_trait,
const_trait_bound_opt_out,
const_trait_impl,
const_try,
constant,
constructor,
context,
copy,
copy_closures,
copy_nonoverlapping,
copysignf32,
copysignf64,
core,
core_panic,
core_panic_2015_macro,
core_panic_2021_macro,
core_panic_macro,
cosf32,
cosf64,
count,
cr,
crate_id,
crate_in_paths,
crate_local,
crate_name,
crate_type,
crate_visibility_modifier,
crt_dash_static: "crt-static",
csky_target_feature,
cstring_type,
ctlz,
ctlz_nonzero,
ctpop,
cttz,
cttz_nonzero,
custom_attribute,
custom_derive,
custom_inner_attributes,
custom_mir,
custom_test_frameworks,
d,
d32,
dbg_macro,
dead_code,
dealloc,
debug,
debug_assert_eq_macro,
debug_assert_macro,
debug_assert_ne_macro,
debug_assertions,
debug_struct,
debug_struct_fields_finish,
debug_tuple,
debug_tuple_fields_finish,
debugger_visualizer,
decl_macro,
declare_lint_pass,
decode,
default_alloc_error_handler,
default_lib_allocator,
default_method_body_is_const,
default_type_parameter_fallback,
default_type_params,
delay_span_bug_from_inside_query,
deny,
deprecated,
deprecated_safe,
deprecated_suggestion,
deref,
deref_method,
deref_mut,
deref_target,
derive,
derive_const,
derive_default_enum,
destruct,
destructuring_assignment,
diagnostic,
diagnostic_namespace,
direct,
discriminant_kind,
discriminant_type,
discriminant_value,
dispatch_from_dyn,
div,
div_assign,
do_not_recommend,
doc,
doc_alias,
doc_auto_cfg,
doc_cfg,
doc_cfg_hide,
doc_keyword,
doc_masked,
doc_notable_trait,
doc_primitive,
doc_spotlight,
doctest,
document_private_items,
dotdot: "..",
dotdot_in_tuple_patterns,
dotdoteq_in_patterns,
dreg,
dreg_low16,
dreg_low8,
drop,
drop_in_place,
drop_types_in_const,
dropck_eyepatch,
dropck_parametricity,
dylib,
dyn_metadata,
dyn_star,
dyn_trait,
dynamic_no_pic: "dynamic-no-pic",
e,
edition_panic,
effects,
eh_catch_typeinfo,
eh_personality,
emit,
emit_enum,
emit_enum_variant,
emit_enum_variant_arg,
emit_struct,
emit_struct_field,
enable,
encode,
end,
env,
eprint_macro,
eprintln_macro,
eq,
ermsb_target_feature,
exact_div,
except,
exchange_malloc,
exclusive_range_pattern,
exhaustive_integer_patterns,
exhaustive_patterns,
existential_type,
exp2f32,
exp2f64,
expect,
expected,
expf32,
expf64,
explicit_generic_args_with_impl_trait,
explicit_tail_calls,
export_name,
expr,
extended_key_value_attributes,
extended_varargs_abi_support,
extern_absolute_paths,
extern_crate_item_prelude,
extern_crate_self,
extern_in_paths,
extern_prelude,
extern_types,
external_doc,
f,
f16c_target_feature,
f32,
f32_nan,
f64,
f64_nan,
fabsf32,
fabsf64,
fadd_fast,
fake_variadic,
fdiv_fast,
feature,
fence,
ferris: "🦀",
fetch_update,
ffi,
ffi_const,
ffi_pure,
ffi_returns_twice,
field,
field_init_shorthand,
file,
fill,
flags,
float,
float_to_int_unchecked,
floorf32,
floorf64,
fmaf32,
fmaf64,
fmt,
fmul_fast,
fn_align,
fn_must_use,
fn_mut,
fn_once,
fn_once_output,
fn_ptr_addr,
fn_ptr_trait,
forbid,
forget,
format,
format_alignment,
format_args,
format_args_capture,
format_args_macro,
format_args_nl,
format_argument,
format_arguments,
format_count,
format_macro,
format_placeholder,
format_unsafe_arg,
freeze,
freg,
frem_fast,
from,
from_desugaring,
from_fn,
from_iter,
from_output,
from_residual,
from_size_align_unchecked,
from_usize,
from_yeet,
fsub_fast,
fundamental,
future,
future_trait,
gdb_script_file,
ge,
gen_future,
gen_kill,
generator,
generator_clone,
generator_state,
generators,
generic_arg_infer,
generic_assert,
generic_associated_types,
generic_associated_types_extended,
generic_const_exprs,
generic_const_items,
generic_param_attrs,
get_context,
global_allocator,
global_asm,
globs,
gt,
half_open_range_patterns,
half_open_range_patterns_in_slices,
hash,
hexagon_target_feature,
hidden,
homogeneous_aggregate,
host,
html_favicon_url,
html_logo_url,
html_no_source,
html_playground_url,
html_root_url,
hwaddress,
i,
i128,
i128_type,
i16,
i32,
i64,
i8,
ident,
if_let,
if_let_guard,
if_while_or_patterns,
ignore,
impl_header_lifetime_elision,
impl_lint_pass,
impl_trait_in_assoc_type,
impl_trait_in_bindings,
impl_trait_in_fn_trait_return,
impl_trait_projections,
implement_via_object,
implied_by,
import,
import_name_type,
import_shadowing,
imported_main,
in_band_lifetimes,
include,
include_bytes,
include_bytes_macro,
include_str,
include_str_macro,
inclusive_range_syntax,
index,
index_mut,
infer_outlives_requirements,
infer_static_outlives_requirements,
inherent_associated_types,
inherit,
inlateout,
inline,
inline_const,
inline_const_pat,
inout,
instruction_set,
integer_: "integer",
integral,
into_future,
into_iter,
intra_doc_pointers,
intrinsics,
irrefutable_let_patterns,
isa_attribute,
isize,
issue,
issue_5723_bootstrap,
issue_tracker_base_url,
item,
item_like_imports,
iter,
iter_mut,
iter_repeat,
iterator_collect_fn,
kcfi,
keyword,
kind,
kreg,
kreg0,
label,
label_break_value,
lang,
lang_items,
large_assignments,
lateout,
lazy_normalization_consts,
lazy_type_alias,
le,
len,
let_chains,
let_else,
lhs,
lib,
libc,
lifetime,
lifetimes,
likely,
line,
link,
link_args,
link_cfg,
link_llvm_intrinsics,
link_name,
link_ordinal,
link_section,
linkage,
linker,
lint_reasons,
literal,
load,
loaded_from_disk,
local,
local_inner_macros,
log10f32,
log10f64,
log2f32,
log2f64,
log_syntax,
logf32,
logf64,
loop_break_value,
lt,
macro_at_most_once_rep,
macro_attributes_in_derive_output,
macro_escape,
macro_export,
macro_lifetime_matcher,
macro_literal_matcher,
macro_metavar_expr,
macro_reexport,
macro_use,
macro_vis_matcher,
macros_in_extern,
main,
managed_boxes,
manually_drop,
map,
marker,
marker_trait_attr,
masked,
match_beginning_vert,
match_default_bindings,
matches_macro,
maxnumf32,
maxnumf64,
may_dangle,
may_unwind,
maybe_uninit,
maybe_uninit_uninit,
maybe_uninit_zeroed,
mem_discriminant,
mem_drop,
mem_forget,
mem_replace,
mem_size_of,
mem_size_of_val,
mem_uninitialized,
mem_variant_count,
mem_zeroed,
member_constraints,
memory,
memtag,
message,
meta,
metadata_type,
min_align_of,
min_align_of_val,
min_const_fn,
min_const_generics,
min_const_unsafe_fn,
min_specialization,
min_type_alias_impl_trait,
minnumf32,
minnumf64,
mips_target_feature,
miri,
misc,
mmx_reg,
modifiers,
module,
module_path,
more_qualified_paths,
more_struct_aliases,
movbe_target_feature,
move_ref_pattern,
move_size_limit,
mul,
mul_assign,
mul_with_overflow,
multiple_supertrait_upcastable,
must_not_suspend,
must_use,
naked,
naked_functions,
name,
names,
native_link_modifiers,
native_link_modifiers_as_needed,
native_link_modifiers_bundle,
native_link_modifiers_verbatim,
native_link_modifiers_whole_archive,
natvis_file,
ne,
nearbyintf32,
nearbyintf64,
needs_allocator,
needs_drop,
needs_panic_runtime,
neg,
negate_unsigned,
negative_bounds,
negative_impls,
neon,
never,
never_type,
never_type_fallback,
new,
new_binary,
new_const,
new_debug,
new_display,
new_lower_exp,
new_lower_hex,
new_octal,
new_pointer,
new_unchecked,
new_upper_exp,
new_upper_hex,
new_v1,
new_v1_formatted,
next,
nll,
no,
no_builtins,
no_core,
no_coverage,
no_crate_inject,
no_debug,
no_default_passes,
no_implicit_prelude,
no_inline,
no_link,
no_main,
no_mangle,
no_sanitize,
no_stack_check,
no_start,
no_std,
nomem,
non_ascii_idents,
non_exhaustive,
non_exhaustive_omitted_patterns_lint,
non_lifetime_binders,
non_modrs_mods,
none,
nontemporal_store,
noop_method_borrow,
noop_method_clone,
noop_method_deref,
noreturn,
nostack,
not,
notable_trait,
note,
object_safe_for_dispatch,
of,
offset,
offset_of,
omit_gdb_pretty_printer_section,
on,
on_unimplemented,
oom,
opaque,
ops,
opt_out_copy,
optimize,
optimize_attribute,
optin_builtin_traits,
option,
option_env,
option_payload_ptr,
options,
or,
or_patterns,
other,
out,
overflow_checks,
overlapping_marker_traits,
owned_box,
packed,
packed_bundled_libs,
panic,
panic_2015,
panic_2021,
panic_abort,
panic_bounds_check,
panic_cannot_unwind,
panic_display,
panic_fmt,
panic_handler,
panic_impl,
panic_implementation,
panic_info,
panic_location,
panic_misaligned_pointer_dereference,
panic_nounwind,
panic_runtime,
panic_str,
panic_unwind,
panicking,
param_attrs,
parent_label,
partial_cmp,
partial_ord,
passes,
pat,
pat_param,
path,
pattern_parentheses,
phantom_data,
pic,
pie,
pin,
platform_intrinsics,
plugin,
plugin_registrar,
plugins,
pointee_trait,
pointer,
pointer_like,
poll,
position,
post_dash_lto: "post-lto",
powerpc_target_feature,
powf32,
powf64,
powif32,
powif64,
pre_dash_lto: "pre-lto",
precise_pointer_size_matching,
precision,
pref_align_of,
prefetch_read_data,
prefetch_read_instruction,
prefetch_write_data,
prefetch_write_instruction,
preg,
prelude,
prelude_import,
preserves_flags,
primitive,
print_macro,
println_macro,
proc_dash_macro: "proc-macro",
proc_macro,
proc_macro_attribute,
proc_macro_derive,
proc_macro_expr,
proc_macro_gen,
proc_macro_hygiene,
proc_macro_internals,
proc_macro_mod,
proc_macro_non_items,
proc_macro_path_invoc,
profiler_builtins,
profiler_runtime,
ptr,
ptr_cast,
ptr_cast_const,
ptr_cast_mut,
ptr_const_is_null,
ptr_from_mut,
ptr_from_ref,
ptr_guaranteed_cmp,
ptr_is_null,
ptr_mask,
ptr_null,
ptr_null_mut,
ptr_offset_from,
ptr_offset_from_unsigned,
ptr_unique,
pub_macro_rules,
pub_restricted,
public,
pure,
pushpop_unsafe,
qreg,
qreg_low4,
qreg_low8,
quad_precision_float,
question_mark,
quote,
range_inclusive_new,
raw_dylib,
raw_eq,
raw_identifiers,
raw_ref_op,
re_rebalance_coherence,
read_enum,
read_enum_variant,
read_enum_variant_arg,
read_struct,
read_struct_field,
read_via_copy,
readonly,
realloc,
reason,
receiver,
recursion_limit,
reexport_test_harness_main,
ref_unwind_safe_trait,
reference,
reflect,
reg,
reg16,
reg32,
reg64,
reg_abcd,
reg_addr,
reg_byte,
reg_data,
reg_iw,
reg_nonzero,
reg_pair,
reg_ptr,
reg_upper,
register_attr,
register_tool,
relaxed_adts,
relaxed_struct_unsize,
relocation_model,
rem,
rem_assign,
repr,
repr128,
repr_align,
repr_align_enum,
repr_packed,
repr_simd,
repr_transparent,
require,
residual,
result,
resume,
return_position_impl_trait_in_trait,
return_type_notation,
rhs,
rintf32,
rintf64,
riscv_target_feature,
rlib,
ropi,
ropi_rwpi: "ropi-rwpi",
rotate_left,
rotate_right,
roundevenf32,
roundevenf64,
roundf32,
roundf64,
rt,
rtm_target_feature,
rust,
rust_2015,
rust_2015_preview,
rust_2018,
rust_2018_preview,
rust_2021,
rust_2021_preview,
rust_2024,
rust_2024_preview,
rust_begin_unwind,
rust_cold_cc,
rust_eh_catch_typeinfo,
rust_eh_personality,
rustc,
rustc_allocator,
rustc_allocator_zeroed,
rustc_allow_const_fn_unstable,
rustc_allow_incoherent_impl,
rustc_allowed_through_unstable_modules,
rustc_attrs,
rustc_box,
rustc_builtin_macro,
rustc_capture_analysis,
rustc_clean,
rustc_coherence_is_core,
rustc_coinductive,
rustc_confusables,
rustc_const_stable,
rustc_const_unstable,
rustc_conversion_suggestion,
rustc_deallocator,
rustc_def_path,
rustc_default_body_unstable,
rustc_deny_explicit_impl,
rustc_diagnostic_item,
rustc_diagnostic_macros,
rustc_dirty,
rustc_do_not_const_check,
rustc_doc_primitive,
rustc_dummy,
rustc_dump_env_program_clauses,
rustc_dump_program_clauses,
rustc_dump_user_args,
rustc_dump_vtable,
rustc_effective_visibility,
rustc_error,
rustc_evaluate_where_clauses,
rustc_expected_cgu_reuse,
rustc_has_incoherent_inherent_impls,
rustc_host,
rustc_if_this_changed,
rustc_inherit_overflow_checks,
rustc_insignificant_dtor,
rustc_layout,
rustc_layout_scalar_valid_range_end,
rustc_layout_scalar_valid_range_start,
rustc_legacy_const_generics,
rustc_lint_diagnostics,
rustc_lint_opt_deny_field_access,
rustc_lint_opt_ty,
rustc_lint_query_instability,
rustc_macro_transparency,
rustc_main,
rustc_mir,
rustc_must_implement_one_of,
rustc_nonnull_optimization_guaranteed,
rustc_nounwind,
rustc_object_lifetime_default,
rustc_on_unimplemented,
rustc_outlives,
rustc_paren_sugar,
rustc_partition_codegened,
rustc_partition_reused,
rustc_pass_by_value,
rustc_peek,
rustc_peek_definite_init,
rustc_peek_liveness,
rustc_peek_maybe_init,
rustc_peek_maybe_uninit,
rustc_polymorphize_error,
rustc_private,
rustc_proc_macro_decls,
rustc_promotable,
rustc_reallocator,
rustc_regions,
rustc_reservation_impl,
rustc_safe_intrinsic,
rustc_serialize,
rustc_skip_array_during_method_dispatch,
rustc_specialization_trait,
rustc_std_internal_symbol,
rustc_strict_coherence,
rustc_symbol_name,
rustc_test_marker,
rustc_then_this_would_need,
rustc_trivial_field_reads,
rustc_unsafe_specialization_marker,
rustc_variance,
rustdoc,
rustdoc_internals,
rustdoc_missing_doc_code_examples,
rustfmt,
rvalue_static_promotion,
rwpi,
s,
safety,
sanitize,
sanitizer_cfi_generalize_pointers,
sanitizer_cfi_normalize_integers,
sanitizer_runtime,
saturating_add,
saturating_sub,
self_in_typedefs,
self_struct_ctor,
semitransparent,
shadow_call_stack,
shl,
shl_assign,
should_panic,
shr,
shr_assign,
sig_dfl,
sig_ign,
simd,
simd_add,
simd_and,
simd_arith_offset,
simd_as,
simd_bitmask,
simd_bitreverse,
simd_bswap,
simd_cast,
simd_cast_ptr,
simd_ceil,
simd_ctlz,
simd_cttz,
simd_div,
simd_eq,
simd_expose_addr,
simd_extract,
simd_fabs,
simd_fcos,
simd_fexp,
simd_fexp2,
simd_ffi,
simd_flog,
simd_flog10,
simd_flog2,
simd_floor,
simd_fma,
simd_fmax,
simd_fmin,
simd_fpow,
simd_fpowi,
simd_from_exposed_addr,
simd_fsin,
simd_fsqrt,
simd_gather,
simd_ge,
simd_gt,
simd_insert,
simd_le,
simd_lt,
simd_mul,
simd_ne,
simd_neg,
simd_or,
simd_reduce_add_ordered,
simd_reduce_add_unordered,
simd_reduce_all,
simd_reduce_and,
simd_reduce_any,
simd_reduce_max,
simd_reduce_max_nanless,
simd_reduce_min,
simd_reduce_min_nanless,
simd_reduce_mul_ordered,
simd_reduce_mul_unordered,
simd_reduce_or,
simd_reduce_xor,
simd_rem,
simd_round,
simd_saturating_add,
simd_saturating_sub,
simd_scatter,
simd_select,
simd_select_bitmask,
simd_shl,
simd_shr,
simd_shuffle,
simd_sub,
simd_trunc,
simd_xor,
since,
sinf32,
sinf64,
size,
size_of,
size_of_val,
sized,
skip,
slice,
slice_len_fn,
slice_patterns,
slicing_syntax,
soft,
specialization,
speed,
spotlight,
sqrtf32,
sqrtf64,
sreg,
sreg_low16,
sse,
sse4a_target_feature,
stable,
staged_api,
start,
state,
static_in_const,
static_nobundle,
static_recursion,
staticlib,
std,
std_panic,
std_panic_2015_macro,
std_panic_macro,
stmt,
stmt_expr_attributes,
stop_after_dataflow,
store,
str,
str_from_utf8,
str_from_utf8_mut,
str_from_utf8_unchecked,
str_from_utf8_unchecked_mut,
str_split_whitespace,
str_trim,
str_trim_end,
str_trim_start,
strict_provenance,
string_deref_patterns,
stringify,
struct_field_attributes,
struct_inherit,
struct_variant,
structural_match,
structural_peq,
structural_teq,
sty,
sub,
sub_assign,
sub_with_overflow,
suggestion,
sym,
sync,
t32,
target,
target_abi,
target_arch,
target_endian,
target_env,
target_family,
target_feature,
target_feature_11,
target_has_atomic,
target_has_atomic_equal_alignment,
target_has_atomic_load_store,
target_os,
target_pointer_width,
target_thread_local,
target_vendor,
tbm_target_feature,
termination,
termination_trait,
termination_trait_test,
test,
test_2018_feature,
test_accepted_feature,
test_case,
test_removed_feature,
test_runner,
test_unstable_lint,
thread,
thread_local,
thread_local_macro,
thumb2,
thumb_mode: "thumb-mode",
tmm_reg,
to_string,
to_vec,
todo_macro,
tool_attributes,
tool_lints,
trace_macros,
track_caller,
trait_alias,
trait_upcasting,
transmute,
transmute_generic_consts,
transmute_opts,
transmute_trait,
transmute_unchecked,
transparent,
transparent_enums,
transparent_unions,
trivial_bounds,
truncf32,
truncf64,
try_blocks,
try_capture,
try_from,
try_into,
try_trait_v2,
tt,
tuple,
tuple_indexing,
tuple_trait,
two_phase,
ty,
type_alias_enum_variants,
type_alias_impl_trait,
type_ascribe,
type_ascription,
type_changing_struct_update,
type_id,
type_length_limit,
type_macros,
type_name,
type_privacy_lints,
u128,
u16,
u32,
u64,
u8,
unaligned_volatile_load,
unaligned_volatile_store,
unboxed_closures,
unchecked_add,
unchecked_div,
unchecked_mul,
unchecked_rem,
unchecked_shl,
unchecked_shr,
unchecked_sub,
underscore_const_names,
underscore_imports,
underscore_lifetimes,
uniform_paths,
unimplemented_macro,
unit,
universal_impl_trait,
unix,
unix_sigpipe,
unlikely,
unmarked_api,
unpin,
unreachable,
unreachable_2015,
unreachable_2015_macro,
unreachable_2021,
unreachable_code,
unreachable_display,
unreachable_macro,
unrestricted_attribute_tokens,
unsafe_block_in_unsafe_fn,
unsafe_cell,
unsafe_cell_from_mut,
unsafe_no_drop_flag,
unsafe_pin_internals,
unsize,
unsized_fn_params,
unsized_locals,
unsized_tuple_coercion,
unstable,
unstable_location_reason_default: "this crate is being loaded from the sysroot, an \
unstable location; did you mean to load this crate \
from crates.io via `Cargo.toml` instead?",
untagged_unions,
unused_imports,
unwind,
unwind_attributes,
unwind_safe_trait,
unwrap,
unwrap_or,
use_extern_macros,
use_nested_groups,
used,
used_with_arg,
using,
usize,
v1,
va_arg,
va_copy,
va_end,
va_list,
va_start,
val,
validity,
values,
var,
variant_count,
vec,
vec_macro,
version,
vfp2,
vis,
visible_private_types,
volatile,
volatile_copy_memory,
volatile_copy_nonoverlapping_memory,
volatile_load,
volatile_set_memory,
volatile_store,
vreg,
vreg_low16,
vtable_align,
vtable_size,
warn,
wasm_abi,
wasm_import_module,
wasm_target_feature,
while_let,
width,
windows,
windows_subsystem,
with_negative_coherence,
wrapping_add,
wrapping_mul,
wrapping_sub,
wreg,
write_bytes,
write_macro,
write_str,
write_via_move,
writeln_macro,
x87_reg,
xer,
xmm_reg,
yeet_desugar_details,
yeet_expr,
ymm_reg,
zmm_reg,
}
}
#[derive(Copy, Clone, Eq, HashStable_Generic, Encodable, Decodable)]
pub struct Ident {
pub name: Symbol,
pub span: Span,
}
impl Ident {
#[inline]
/// Constructs a new identifier from a symbol and a span.
pub const fn new(name: Symbol, span: Span) -> Ident {
Ident { name, span }
}
/// Constructs a new identifier with a dummy span.
#[inline]
pub const fn with_dummy_span(name: Symbol) -> Ident {
Ident::new(name, DUMMY_SP)
}
#[inline]
pub fn empty() -> Ident {
Ident::with_dummy_span(kw::Empty)
}
/// Maps a string to an identifier with a dummy span.
pub fn from_str(string: &str) -> Ident {
Ident::with_dummy_span(Symbol::intern(string))
}
/// Maps a string and a span to an identifier.
pub fn from_str_and_span(string: &str, span: Span) -> Ident {
Ident::new(Symbol::intern(string), span)
}
/// Replaces `lo` and `hi` with those from `span`, but keep hygiene context.
pub fn with_span_pos(self, span: Span) -> Ident {
Ident::new(self.name, span.with_ctxt(self.span.ctxt()))
}
pub fn without_first_quote(self) -> Ident {
Ident::new(Symbol::intern(self.as_str().trim_start_matches('\'')), self.span)
}
/// "Normalize" ident for use in comparisons using "item hygiene".
/// Identifiers with same string value become same if they came from the same macro 2.0 macro
/// (e.g., `macro` item, but not `macro_rules` item) and stay different if they came from
/// different macro 2.0 macros.
/// Technically, this operation strips all non-opaque marks from ident's syntactic context.
pub fn normalize_to_macros_2_0(self) -> Ident {
Ident::new(self.name, self.span.normalize_to_macros_2_0())
}
/// "Normalize" ident for use in comparisons using "local variable hygiene".
/// Identifiers with same string value become same if they came from the same non-transparent
/// macro (e.g., `macro` or `macro_rules!` items) and stay different if they came from different
/// non-transparent macros.
/// Technically, this operation strips all transparent marks from ident's syntactic context.
#[inline]
pub fn normalize_to_macro_rules(self) -> Ident {
Ident::new(self.name, self.span.normalize_to_macro_rules())
}
/// Access the underlying string. This is a slowish operation because it
/// requires locking the symbol interner.
///
/// Note that the lifetime of the return value is a lie. See
/// `Symbol::as_str()` for details.
pub fn as_str(&self) -> &str {
self.name.as_str()
}
}
impl PartialEq for Ident {
#[inline]
fn eq(&self, rhs: &Self) -> bool {
self.name == rhs.name && self.span.eq_ctxt(rhs.span)
}
}
impl Hash for Ident {
fn hash<H: Hasher>(&self, state: &mut H) {
self.name.hash(state);
self.span.ctxt().hash(state);
}
}
impl fmt::Debug for Ident {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)?;
fmt::Debug::fmt(&self.span.ctxt(), f)
}
}
/// This implementation is supposed to be used in error messages, so it's expected to be identical
/// to printing the original identifier token written in source code (`token_to_string`),
/// except that AST identifiers don't keep the rawness flag, so we have to guess it.
impl fmt::Display for Ident {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&IdentPrinter::new(self.name, self.is_raw_guess(), None), f)
}
}
/// The most general type to print identifiers.
///
/// AST pretty-printer is used as a fallback for turning AST structures into token streams for
/// proc macros. Additionally, proc macros may stringify their input and expect it survive the
/// stringification (especially true for proc macro derives written between Rust 1.15 and 1.30).
/// So we need to somehow pretty-print `$crate` in a way preserving at least some of its
/// hygiene data, most importantly name of the crate it refers to.
/// As a result we print `$crate` as `crate` if it refers to the local crate
/// and as `::other_crate_name` if it refers to some other crate.
/// Note, that this is only done if the ident token is printed from inside of AST pretty-printing,
/// but not otherwise. Pretty-printing is the only way for proc macros to discover token contents,
/// so we should not perform this lossy conversion if the top level call to the pretty-printer was
/// done for a token stream or a single token.
pub struct IdentPrinter {
symbol: Symbol,
is_raw: bool,
/// Span used for retrieving the crate name to which `$crate` refers to,
/// if this field is `None` then the `$crate` conversion doesn't happen.
convert_dollar_crate: Option<Span>,
}
impl IdentPrinter {
/// The most general `IdentPrinter` constructor. Do not use this.
pub fn new(symbol: Symbol, is_raw: bool, convert_dollar_crate: Option<Span>) -> IdentPrinter {
IdentPrinter { symbol, is_raw, convert_dollar_crate }
}
/// This implementation is supposed to be used when printing identifiers
/// as a part of pretty-printing for larger AST pieces.
/// Do not use this either.
pub fn for_ast_ident(ident: Ident, is_raw: bool) -> IdentPrinter {
IdentPrinter::new(ident.name, is_raw, Some(ident.span))
}
}
impl fmt::Display for IdentPrinter {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if self.is_raw {
f.write_str("r#")?;
} else if self.symbol == kw::DollarCrate {
if let Some(span) = self.convert_dollar_crate {
let converted = span.ctxt().dollar_crate_name();
if !converted.is_path_segment_keyword() {
f.write_str("::")?;
}
return fmt::Display::fmt(&converted, f);
}
}
fmt::Display::fmt(&self.symbol, f)
}
}
/// An newtype around `Ident` that calls [Ident::normalize_to_macro_rules] on
/// construction.
// FIXME(matthewj, petrochenkov) Use this more often, add a similar
// `ModernIdent` struct and use that as well.
#[derive(Copy, Clone, Eq, PartialEq, Hash)]
pub struct MacroRulesNormalizedIdent(Ident);
impl MacroRulesNormalizedIdent {
pub fn new(ident: Ident) -> Self {
Self(ident.normalize_to_macro_rules())
}
}
impl fmt::Debug for MacroRulesNormalizedIdent {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&self.0, f)
}
}
impl fmt::Display for MacroRulesNormalizedIdent {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&self.0, f)
}
}
/// An interned string.
///
/// Internally, a `Symbol` is implemented as an index, and all operations
/// (including hashing, equality, and ordering) operate on that index. The use
/// of `rustc_index::newtype_index!` means that `Option<Symbol>` only takes up 4 bytes,
/// because `rustc_index::newtype_index!` reserves the last 256 values for tagging purposes.
///
/// Note that `Symbol` cannot directly be a `rustc_index::newtype_index!` because it
/// implements `fmt::Debug`, `Encodable`, and `Decodable` in special ways.
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Symbol(SymbolIndex);
rustc_index::newtype_index! {
struct SymbolIndex {}
}
impl Symbol {
const fn new(n: u32) -> Self {
Symbol(SymbolIndex::from_u32(n))
}
/// for use in Decoder only
pub fn new_from_decoded(n: u32) -> Self {
Self::new(n)
}
/// Maps a string to its interned representation.
pub fn intern(string: &str) -> Self {
with_session_globals(|session_globals| session_globals.symbol_interner.intern(string))
}
/// Access the underlying string. This is a slowish operation because it
/// requires locking the symbol interner.
///
/// Note that the lifetime of the return value is a lie. It's not the same
/// as `&self`, but actually tied to the lifetime of the underlying
/// interner. Interners are long-lived, and there are very few of them, and
/// this function is typically used for short-lived things, so in practice
/// it works out ok.
pub fn as_str(&self) -> &str {
with_session_globals(|session_globals| unsafe {
std::mem::transmute::<&str, &str>(session_globals.symbol_interner.get(*self))
})
}
pub fn as_u32(self) -> u32 {
self.0.as_u32()
}
pub fn is_empty(self) -> bool {
self == kw::Empty
}
/// This method is supposed to be used in error messages, so it's expected to be
/// identical to printing the original identifier token written in source code
/// (`token_to_string`, `Ident::to_string`), except that symbols don't keep the rawness flag
/// or edition, so we have to guess the rawness using the global edition.
pub fn to_ident_string(self) -> String {
Ident::with_dummy_span(self).to_string()
}
}
impl fmt::Debug for Symbol {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(self.as_str(), f)
}
}
impl fmt::Display for Symbol {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self.as_str(), f)
}
}
// takes advantage of `str::to_string` specialization
impl ToString for Symbol {
fn to_string(&self) -> String {
self.as_str().to_string()
}
}
impl<S: Encoder> Encodable<S> for Symbol {
default fn encode(&self, s: &mut S) {
s.emit_str(self.as_str());
}
}
impl<D: Decoder> Decodable<D> for Symbol {
#[inline]
default fn decode(d: &mut D) -> Symbol {
Symbol::intern(d.read_str())
}
}
impl<CTX> HashStable<CTX> for Symbol {
#[inline]
fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
self.as_str().hash_stable(hcx, hasher);
}
}
impl<CTX> ToStableHashKey<CTX> for Symbol {
type KeyType = String;
#[inline]
fn to_stable_hash_key(&self, _: &CTX) -> String {
self.as_str().to_string()
}
}
#[derive(Default)]
pub(crate) struct Interner(Lock<InternerInner>);
// The `&'static str`s in this type actually point into the arena.
//
// The `FxHashMap`+`Vec` pair could be replaced by `FxIndexSet`, but #75278
// found that to regress performance up to 2% in some cases. This might be
// revisited after further improvements to `indexmap`.
//
// This type is private to prevent accidentally constructing more than one
// `Interner` on the same thread, which makes it easy to mix up `Symbol`s
// between `Interner`s.
#[derive(Default)]
struct InternerInner {
arena: DroplessArena,
names: FxHashMap<&'static str, Symbol>,
strings: Vec<&'static str>,
}
impl Interner {
fn prefill(init: &[&'static str]) -> Self {
Interner(Lock::new(InternerInner {
strings: init.into(),
names: init.iter().copied().zip((0..).map(Symbol::new)).collect(),
..Default::default()
}))
}
#[inline]
fn intern(&self, string: &str) -> Symbol {
let mut inner = self.0.lock();
if let Some(&name) = inner.names.get(string) {
return name;
}
let name = Symbol::new(inner.strings.len() as u32);
// SAFETY: we convert from `&str` to `&[u8]`, clone it into the arena,
// and immediately convert the clone back to `&[u8]`, all because there
// is no `inner.arena.alloc_str()` method. This is clearly safe.
let string: &str =
unsafe { str::from_utf8_unchecked(inner.arena.alloc_slice(string.as_bytes())) };
// SAFETY: we can extend the arena allocation to `'static` because we
// only access these while the arena is still alive.
let string: &'static str = unsafe { &*(string as *const str) };
inner.strings.push(string);
// This second hash table lookup can be avoided by using `RawEntryMut`,
// but this code path isn't hot enough for it to be worth it. See
// #91445 for details.
inner.names.insert(string, name);
name
}
/// Get the symbol as a string.
///
/// [`Symbol::as_str()`] should be used in preference to this function.
fn get(&self, symbol: Symbol) -> &str {
self.0.lock().strings[symbol.0.as_usize()]
}
}
// This module has a very short name because it's used a lot.
/// This module contains all the defined keyword `Symbol`s.
///
/// Given that `kw` is imported, use them like `kw::keyword_name`.
/// For example `kw::Loop` or `kw::Break`.
pub mod kw {
pub use super::kw_generated::*;
}
// This module has a very short name because it's used a lot.
/// This module contains all the defined non-keyword `Symbol`s.
///
/// Given that `sym` is imported, use them like `sym::symbol_name`.
/// For example `sym::rustfmt` or `sym::u8`.
pub mod sym {
use super::Symbol;
#[doc(inline)]
pub use super::sym_generated::*;
// Used from a macro in `librustc_feature/accepted.rs`
pub use super::kw::MacroRules as macro_rules;
/// Get the symbol for an integer.
///
/// The first few non-negative integers each have a static symbol and therefore
/// are fast.
pub fn integer<N: TryInto<usize> + Copy + ToString>(n: N) -> Symbol {
if let Result::Ok(idx) = n.try_into() {
if idx < 10 {
return Symbol::new(super::SYMBOL_DIGITS_BASE + idx as u32);
}
}
Symbol::intern(&n.to_string())
}
}
impl Symbol {
fn is_special(self) -> bool {
self <= kw::Underscore
}
fn is_used_keyword_always(self) -> bool {
self >= kw::As && self <= kw::While
}
fn is_used_keyword_conditional(self, edition: impl FnOnce() -> Edition) -> bool {
(self >= kw::Async && self <= kw::Dyn) && edition() >= Edition::Edition2018
}
fn is_unused_keyword_always(self) -> bool {
self >= kw::Abstract && self <= kw::Yield
}
fn is_unused_keyword_conditional(self, edition: impl FnOnce() -> Edition) -> bool {
self == kw::Try && edition() >= Edition::Edition2018
}
pub fn is_reserved(self, edition: impl Copy + FnOnce() -> Edition) -> bool {
self.is_special()
|| self.is_used_keyword_always()
|| self.is_unused_keyword_always()
|| self.is_used_keyword_conditional(edition)
|| self.is_unused_keyword_conditional(edition)
}
/// A keyword or reserved identifier that can be used as a path segment.
pub fn is_path_segment_keyword(self) -> bool {
self == kw::Super
|| self == kw::SelfLower
|| self == kw::SelfUpper
|| self == kw::Crate
|| self == kw::PathRoot
|| self == kw::DollarCrate
}
/// Returns `true` if the symbol is `true` or `false`.
pub fn is_bool_lit(self) -> bool {
self == kw::True || self == kw::False
}
/// Returns `true` if this symbol can be a raw identifier.
pub fn can_be_raw(self) -> bool {
self != kw::Empty && self != kw::Underscore && !self.is_path_segment_keyword()
}
/// Is this symbol was interned in compiler's `symbols!` macro
pub fn is_preinterned(self) -> bool {
self.as_u32() < PREINTERNED_SYMBOLS_COUNT
}
}
impl Ident {
/// Returns `true` for reserved identifiers used internally for elided lifetimes,
/// unnamed method parameters, crate root module, error recovery etc.
pub fn is_special(self) -> bool {
self.name.is_special()
}
/// Returns `true` if the token is a keyword used in the language.
pub fn is_used_keyword(self) -> bool {
// Note: `span.edition()` is relatively expensive, don't call it unless necessary.
self.name.is_used_keyword_always()
|| self.name.is_used_keyword_conditional(|| self.span.edition())
}
/// Returns `true` if the token is a keyword reserved for possible future use.
pub fn is_unused_keyword(self) -> bool {
// Note: `span.edition()` is relatively expensive, don't call it unless necessary.
self.name.is_unused_keyword_always()
|| self.name.is_unused_keyword_conditional(|| self.span.edition())
}
/// Returns `true` if the token is either a special identifier or a keyword.
pub fn is_reserved(self) -> bool {
// Note: `span.edition()` is relatively expensive, don't call it unless necessary.
self.name.is_reserved(|| self.span.edition())
}
/// A keyword or reserved identifier that can be used as a path segment.
pub fn is_path_segment_keyword(self) -> bool {
self.name.is_path_segment_keyword()
}
/// We see this identifier in a normal identifier position, like variable name or a type.
/// How was it written originally? Did it use the raw form? Let's try to guess.
pub fn is_raw_guess(self) -> bool {
self.name.can_be_raw() && self.is_reserved()
}
}