Files
rust/compiler/rustc_span/src/symbol.rs
bors 785c83015c Auto merge of #129458 - EnzymeAD:enzyme-frontend, r=jieyouxu
Autodiff Upstreaming - enzyme frontend

This is an upstream PR for the `autodiff` rustc_builtin_macro that is part of the autodiff feature.

For the full implementation, see: https://github.com/rust-lang/rust/pull/129175

**Content:**
It contains a new `#[autodiff(<args>)]` rustc_builtin_macro, as well as a `#[rustc_autodiff]` builtin attribute.
The autodiff macro is applied on function `f` and will expand to a second function `df` (name given by user).
It will add a dummy body to `df` to make sure it type-checks. The body will later be replaced by enzyme on llvm-ir level,
we therefore don't really care about the content. Most of the changes (700 from 1.2k) are in `compiler/rustc_builtin_macros/src/autodiff.rs`, which expand the macro. Nothing except expansion is implemented for now.
I have a fallback implementation for relevant functions in case that rustc should be build without autodiff support. The default for now will be off, although we want to flip it later (once everything landed) to on for nightly. For the sake of CI, I have flipped the defaults, I'll revert this before merging.

**Dummy function Body:**
The first line is an `inline_asm` nop to make inlining less likely (I have additional checks to prevent this in the middle end of rustc. If `f` gets inlined too early, we can't pass it to enzyme and thus can't differentiate it.
If `df` gets inlined too early, the call site will just compute this dummy code instead of the derivatives, a correctness issue. The following black_box lines make sure that none of the input arguments is getting optimized away before we replace the body.

**Motivation:**
The user facing autodiff macro can verify the user input. Then I write it as args to the rustc_attribute, so from here on I can know that these values should be sensible. A rustc_attribute also turned out to be quite nice to attach this information to the corresponding function and carry it till the backend.
This is also just an experiment, I expect to adjust the user facing autodiff macro based on user feedback, to improve usability.

As a simple example of what this will do, we can see this expansion:
From:
```
#[autodiff(df, Reverse, Duplicated, Const, Active)]
pub fn f1(x: &[f64], y: f64) -> f64 {
    unimplemented!()
}
```
to
```
#[rustc_autodiff]
#[inline(never)]
pub fn f1(x: &[f64], y: f64) -> f64 {
    ::core::panicking::panic("not implemented")
}
#[rustc_autodiff(Reverse, Duplicated, Const, Active,)]
#[inline(never)]
pub fn df(x: &[f64], dx: &mut [f64], y: f64, dret: f64) -> f64 {
    unsafe { asm!("NOP"); };
    ::core::hint::black_box(f1(x, y));
    ::core::hint::black_box((dx, dret));
    ::core::hint::black_box(f1(x, y))
}
```
I will add a few more tests once I figured out why rustc rebuilds every time I touch a test.

Tracking:

- https://github.com/rust-lang/rust/issues/124509

try-job: dist-x86_64-msvc
2024-10-15 01:30:01 +00:00

2694 lines
69 KiB
Rust

//! 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 std::hash::{Hash, Hasher};
use std::{fmt, str};
use rustc_arena::DroplessArena;
use rustc_data_structures::fx::FxIndexSet;
use rustc_data_structures::stable_hasher::{
HashStable, StableCompare, StableHasher, ToStableHashKey,
};
use rustc_data_structures::sync::Lock;
use rustc_macros::{Decodable, Encodable, HashStable_Generic, symbols};
use crate::{DUMMY_SP, Edition, Span, with_session_globals};
#[cfg(test)]
mod tests;
// The proc macro code for this is in `compiler/rustc_macros/src/symbols.rs`.
symbols! {
// If you modify this list, adjust `is_special`, `is_used_keyword`/`is_unused_keyword`
// and `AllKeywords`.
// But this should rarely be necessary 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",
Gen: "gen",
MacroRules: "macro_rules",
Raw: "raw",
Reuse: "reuse",
Safe: "safe",
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 {
Abi,
AcqRel,
Acquire,
Any,
Arc,
ArcWeak,
Argument,
ArgumentMethods,
ArrayIntoIter,
AsMut,
AsRef,
AssertParamIsClone,
AssertParamIsCopy,
AssertParamIsEq,
AsyncGenFinished,
AsyncGenPending,
AsyncGenReady,
AtomicBool,
AtomicI128,
AtomicI16,
AtomicI32,
AtomicI64,
AtomicI8,
AtomicIsize,
AtomicPtr,
AtomicU128,
AtomicU16,
AtomicU32,
AtomicU64,
AtomicU8,
AtomicUsize,
BTreeEntry,
BTreeMap,
BTreeSet,
BinaryHeap,
Borrow,
BorrowMut,
Break,
C,
CStr,
C_dash_unwind: "C-unwind",
CallOnceFuture,
CallRefFuture,
Capture,
Center,
Cleanup,
Clone,
CoerceUnsized,
Command,
ConstParamTy,
ConstParamTy_,
Context,
Continue,
Copy,
Cow,
Debug,
DebugStruct,
Decodable,
Decoder,
Default,
Deref,
DiagMessage,
Diagnostic,
DirBuilder,
DispatchFromDyn,
Display,
DoubleEndedIterator,
Duration,
EffectsCompat,
EffectsIntersection,
EffectsIntersectionOutput,
EffectsMaybe,
EffectsNoRuntime,
EffectsRuntime,
EffectsTyCompat,
Effects__,
Encodable,
Encoder,
Enumerate,
Eq,
Equal,
Err,
Error,
File,
FileType,
Fn,
FnMut,
FnOnce,
Formatter,
From,
FromIterator,
FromResidual,
FsOpenOptions,
FsPermissions,
FusedIterator,
Future,
GlobalAlloc,
Hash,
HashMap,
HashMapEntry,
HashSet,
Hasher,
Implied,
InCleanup,
IndexOutput,
Input,
Instant,
Into,
IntoFuture,
IntoIterator,
IoLines,
IoRead,
IoSeek,
IoWrite,
IpAddr,
IrTyKind,
Is,
Item,
ItemContext,
IterEmpty,
IterOnce,
IterPeekable,
Iterator,
IteratorItem,
Layout,
Left,
LinkedList,
LintDiagnostic,
LintPass,
LocalKey,
Mutex,
MutexGuard,
N,
NonNull,
NonZero,
None,
Normal,
Ok,
Option,
Ord,
Ordering,
OsStr,
OsString,
Output,
Param,
PartialEq,
PartialOrd,
Path,
PathBuf,
Pending,
PinCoerceUnsized,
Pointer,
Poll,
ProcMacro,
ProceduralMasqueradeDummyType,
Range,
RangeBounds,
RangeFrom,
RangeFull,
RangeInclusive,
RangeTo,
RangeToInclusive,
Rc,
RcWeak,
Ready,
Receiver,
RefCell,
RefCellRef,
RefCellRefMut,
Relaxed,
Release,
Result,
ResumeTy,
Return,
Right,
Rust,
RustcDecodable,
RustcEncodable,
RwLock,
RwLockReadGuard,
RwLockWriteGuard,
Saturating,
SeekFrom,
Send,
SeqCst,
Sized,
SliceIndex,
SliceIter,
SmartPointer,
Some,
SpanCtxt,
String,
StructuralPartialEq,
SubdiagMessage,
Subdiagnostic,
Sync,
T,
Target,
ToOwned,
ToString,
TokenStream,
Trait,
Try,
TryCaptureGeneric,
TryCapturePrintable,
TryFrom,
TryInto,
Ty,
TyCtxt,
TyKind,
Unknown,
Unsize,
UnsizedConstParamTy,
Upvars,
Vec,
VecDeque,
Waker,
Wrapper,
Wrapping,
Yield,
_DECLS,
_Self,
__D,
__H,
__S,
__awaitee,
__try_var,
_d,
_e,
_task_context,
a32,
aarch64_target_feature,
aarch64_unstable_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,
aggregate_raw_ptr,
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,
alu32,
always,
and,
and_then,
anon,
anon_adt,
anonymous_lifetime_in_impl_trait,
any,
append_const_msg,
arbitrary_enum_discriminant,
arbitrary_self_types,
arbitrary_self_types_pointers,
areg,
args,
arith_offset,
arm,
arm_target_feature,
array,
as_ptr,
as_ref,
as_str,
asm,
asm_const,
asm_experimental_arch,
asm_goto,
asm_sym,
asm_unwind,
assert,
assert_eq,
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_call,
async_call_mut,
async_call_once,
async_closure,
async_destruct,
async_drop,
async_drop_chain,
async_drop_defer,
async_drop_deferred_drop_in_place,
async_drop_either,
async_drop_fuse,
async_drop_in_place,
async_drop_noop,
async_drop_slice,
async_drop_surface_drop_in_place,
async_fn,
async_fn_in_trait,
async_fn_kind_helper,
async_fn_kind_upvars,
async_fn_mut,
async_fn_once,
async_fn_once_output,
async_fn_track_caller,
async_fn_traits,
async_for_loop,
async_iterator,
async_iterator_poll_next,
atomic,
atomic_mod,
atomics,
att_syntax,
attr,
attr_literals,
attributes,
audit_that,
augmented_assignments,
auto_traits,
autodiff,
autodiff_fallback,
automatically_derived,
avx,
avx512_target_feature,
avx512bw,
avx512f,
await_macro,
bang,
begin_panic,
bench,
bin,
binaryheap_iter,
bind_by_move_pattern_guards,
bindings_after_at,
bitand,
bitand_assign,
bitor,
bitor_assign,
bitreverse,
bitxor,
bitxor_assign,
black_box,
block,
bool,
bool_then,
borrowck_graphviz_format,
borrowck_graphviz_postflow,
box_new,
box_patterns,
box_syntax,
bpf_target_feature,
braced_empty_structs,
branch,
breakpoint,
bridge,
bswap,
btreemap_contains_key,
btreemap_insert,
btreeset_iter,
builtin_syntax,
c,
c_str,
c_str_literals,
c_unwind,
c_variadic,
c_void,
call,
call_mut,
call_once,
call_once_future,
call_ref_future,
caller_location,
capture_disjoint_fields,
catch_unwind,
cause,
cdylib,
ceilf128,
ceilf16,
ceilf32,
ceilf64,
cfg,
cfg_accessible,
cfg_attr,
cfg_attr_multi,
cfg_autodiff_fallback,
cfg_boolean_literals,
cfg_doctest,
cfg_eval,
cfg_fmt_debug,
cfg_hide,
cfg_overflow_checks,
cfg_panic,
cfg_relocation_model,
cfg_sanitize,
cfg_sanitizer_cfi,
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_ub_checks,
cfg_version,
cfi,
cfi_encoding,
char,
client,
clippy,
clobber_abi,
clone,
clone_closures,
clone_fn,
clone_from,
closure,
closure_lifetime_binder,
closure_to_fn_coercion,
closure_track_caller,
cmp,
cmp_max,
cmp_min,
cmp_ord_max,
cmp_ord_min,
cmp_partialeq_eq,
cmp_partialeq_ne,
cmp_partialord_cmp,
cmp_partialord_ge,
cmp_partialord_gt,
cmp_partialord_le,
cmp_partialord_lt,
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_refs_to_static,
const_trait,
const_trait_bound_opt_out,
const_trait_impl,
const_try,
constant,
constructor,
convert_identity,
copy,
copy_closures,
copy_nonoverlapping,
copysignf128,
copysignf16,
copysignf32,
copysignf64,
core,
core_panic,
core_panic_2015_macro,
core_panic_2021_macro,
core_panic_macro,
coroutine,
coroutine_clone,
coroutine_resume,
coroutine_return,
coroutine_state,
coroutine_yield,
coroutines,
cosf128,
cosf16,
cosf32,
cosf64,
count,
coverage,
coverage_attribute,
cr,
crate_id,
crate_in_paths,
crate_local,
crate_name,
crate_type,
crate_visibility_modifier,
crt_dash_static: "crt-static",
csky_target_feature,
cstr_type,
cstring_as_c_str,
cstring_type,
ctlz,
ctlz_nonzero,
ctpop,
cttz,
cttz_nonzero,
custom_attribute,
custom_code_classes_in_docs,
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_fn,
default_lib_allocator,
default_method_body_is_const,
default_type_parameter_fallback,
default_type_params,
delayed_bug_from_inside_query,
deny,
deprecated,
deprecated_safe,
deprecated_suggestion,
deref,
deref_method,
deref_mut,
deref_mut_method,
deref_patterns,
deref_pure,
deref_target,
derive,
derive_const,
derive_default_enum,
derive_smart_pointer,
destruct,
destructuring_assignment,
diagnostic,
diagnostic_namespace,
direct,
discriminant_kind,
discriminant_type,
discriminant_value,
dispatch_from_dyn,
div,
div_assign,
diverging_block_default,
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_compatible_for_dispatch,
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,
entry_nops,
enumerate_method,
env,
env_CFG_RELEASE: env!("CFG_RELEASE"),
eprint_macro,
eprintln_macro,
eq,
ermsb_target_feature,
exact_div,
except,
exchange_malloc,
exclusive_range_pattern,
exhaustive_integer_patterns,
exhaustive_patterns,
existential_type,
exp2f128,
exp2f16,
exp2f32,
exp2f64,
expect,
expected,
expf128,
expf16,
expf32,
expf64,
explicit_generic_args_with_impl_trait,
explicit_tail_calls,
export_name,
expr,
expr_2021,
expr_fragment_specifier_2024,
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,
external_doc,
f,
f128,
f128_nan,
f16,
f16_nan,
f16c_target_feature,
f32,
f32_epsilon,
f32_legacy_const_digits,
f32_legacy_const_epsilon,
f32_legacy_const_infinity,
f32_legacy_const_mantissa_dig,
f32_legacy_const_max,
f32_legacy_const_max_10_exp,
f32_legacy_const_max_exp,
f32_legacy_const_min,
f32_legacy_const_min_10_exp,
f32_legacy_const_min_exp,
f32_legacy_const_min_positive,
f32_legacy_const_nan,
f32_legacy_const_neg_infinity,
f32_legacy_const_radix,
f32_nan,
f64,
f64_epsilon,
f64_legacy_const_digits,
f64_legacy_const_epsilon,
f64_legacy_const_infinity,
f64_legacy_const_mantissa_dig,
f64_legacy_const_max,
f64_legacy_const_max_10_exp,
f64_legacy_const_max_exp,
f64_legacy_const_min,
f64_legacy_const_min_10_exp,
f64_legacy_const_min_exp,
f64_legacy_const_min_positive,
f64_legacy_const_nan,
f64_legacy_const_neg_infinity,
f64_legacy_const_radix,
f64_nan,
fabsf128,
fabsf16,
fabsf32,
fabsf64,
fadd_algebraic,
fadd_fast,
fake_variadic,
fallback,
fallback_surface_drop,
fdiv_algebraic,
fdiv_fast,
feature,
fence,
ferris: "🦀",
fetch_update,
ffi,
ffi_const,
ffi_pure,
ffi_returns_twice,
field,
field_init_shorthand,
file,
file_options,
float,
float_to_int_unchecked,
floorf128,
floorf16,
floorf32,
floorf64,
fmaf128,
fmaf16,
fmaf32,
fmaf64,
fmt,
fmt_debug,
fmul_algebraic,
fmul_fast,
fmuladdf128,
fmuladdf16,
fmuladdf32,
fmuladdf64,
fn_align,
fn_delegation,
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,
freeze_impls,
freg,
frem_algebraic,
frem_fast,
from,
from_desugaring,
from_fn,
from_iter,
from_iter_fn,
from_output,
from_residual,
from_size_align_unchecked,
from_str_method,
from_usize,
from_yeet,
fs_create_dir,
fsub_algebraic,
fsub_fast,
full,
fundamental,
fused_iterator,
future,
future_output,
future_trait,
gdb_script_file,
ge,
gen_blocks,
gen_future,
gen_kill,
generator_clone,
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_alloc_ty,
global_allocator,
global_asm,
global_registration,
globs,
gt,
half_open_range_patterns,
half_open_range_patterns_in_slices,
hash,
hashmap_contains_key,
hashmap_drain_ty,
hashmap_insert,
hashmap_iter_mut_ty,
hashmap_iter_ty,
hashmap_keys_ty,
hashmap_values_mut_ty,
hashmap_values_ty,
hashset_drain_ty,
hashset_iter,
hashset_iter_ty,
hexagon_target_feature,
hidden,
hint,
homogeneous_aggregate,
host,
html_favicon_url,
html_logo_url,
html_no_source,
html_playground_url,
html_root_url,
hwaddress,
i,
i128,
i128_legacy_const_max,
i128_legacy_const_min,
i128_legacy_fn_max_value,
i128_legacy_fn_min_value,
i128_legacy_mod,
i128_type,
i16,
i16_legacy_const_max,
i16_legacy_const_min,
i16_legacy_fn_max_value,
i16_legacy_fn_min_value,
i16_legacy_mod,
i32,
i32_legacy_const_max,
i32_legacy_const_min,
i32_legacy_fn_max_value,
i32_legacy_fn_min_value,
i32_legacy_mod,
i64,
i64_legacy_const_max,
i64_legacy_const_min,
i64_legacy_fn_max_value,
i64_legacy_fn_min_value,
i64_legacy_mod,
i8,
i8_legacy_const_max,
i8_legacy_const_min,
i8_legacy_fn_max_value,
i8_legacy_fn_min_value,
i8_legacy_mod,
ident,
if_let,
if_let_guard,
if_let_rescope,
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,
instant_now,
instruction_set,
integer_: "integer", // underscore to avoid clashing with the function `sym::integer` below
integral,
into_async_iter_into_iter,
into_future,
into_iter,
intra_doc_pointers,
intrinsics,
intrinsics_unaligned_volatile_load,
intrinsics_unaligned_volatile_store,
io_stderr,
io_stdout,
irrefutable_let_patterns,
is,
is_val_statically_known,
isa_attribute,
isize,
isize_legacy_const_max,
isize_legacy_const_min,
isize_legacy_fn_max_value,
isize_legacy_fn_min_value,
isize_legacy_mod,
issue,
issue_5723_bootstrap,
issue_tracker_base_url,
item,
item_like_imports,
iter,
iter_cloned,
iter_copied,
iter_filter,
iter_mut,
iter_repeat,
iterator,
iterator_collect_fn,
kcfi,
keyword,
kind,
kreg,
kreg0,
label,
label_break_value,
lahfsahf_target_feature,
lang,
lang_items,
large_assignments,
lateout,
lazy_normalization_consts,
lazy_type_alias,
le,
len,
let_chains,
let_else,
lhs,
lib,
libc,
lifetime,
lifetime_capture_rules_2024,
lifetimes,
likely,
line,
link,
link_arg_attribute,
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,
log10f128,
log10f16,
log10f32,
log10f64,
log2f128,
log2f16,
log2f32,
log2f64,
log_syntax,
logf128,
logf16,
logf32,
logf64,
loongarch_target_feature,
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_metavar_expr_concat,
macro_reexport,
macro_use,
macro_vis_matcher,
macros_in_extern,
main,
managed_boxes,
manually_drop,
map,
map_err,
marker,
marker_trait_attr,
masked,
match_beginning_vert,
match_default_bindings,
matches_macro,
maxnumf128,
maxnumf16,
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_swap,
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_exhaustive_patterns,
min_specialization,
min_type_alias_impl_trait,
minnumf128,
minnumf16,
minnumf32,
minnumf64,
mips_target_feature,
mir_assume,
mir_basic_block,
mir_call,
mir_cast_ptr_to_ptr,
mir_cast_transmute,
mir_checked,
mir_copy_for_deref,
mir_debuginfo,
mir_deinit,
mir_discriminant,
mir_drop,
mir_field,
mir_goto,
mir_len,
mir_make_place,
mir_move,
mir_offset,
mir_ptr_metadata,
mir_retag,
mir_return,
mir_return_to,
mir_set_discriminant,
mir_static,
mir_static_mut,
mir_storage_dead,
mir_storage_live,
mir_tail_call,
mir_unreachable,
mir_unwind_cleanup,
mir_unwind_continue,
mir_unwind_resume,
mir_unwind_terminate,
mir_unwind_terminate_reason,
mir_unwind_unreachable,
mir_variant,
miri,
mmx_reg,
modifiers,
module,
module_path,
more_maybe_bounds,
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,
mut_preserve_binding_mode_2024,
mut_ref,
naked,
naked_asm,
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,
nearbyintf128,
nearbyintf16,
nearbyintf32,
nearbyintf64,
needs_allocator,
needs_drop,
needs_panic_runtime,
neg,
negate_unsigned,
negative_bounds,
negative_impls,
neon,
nested,
never,
never_patterns,
never_type,
never_type_fallback,
new,
new_binary,
new_const,
new_debug,
new_debug_noop,
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,
niko,
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,
off,
offset,
offset_of,
offset_of_enum,
offset_of_nested,
offset_of_slice,
ok_or_else,
omit_gdb_pretty_printer_section,
on,
on_unimplemented,
opaque,
open_options_new,
ops,
opt_out_copy,
optimize,
optimize_attribute,
optin_builtin_traits,
option,
option_env,
option_expect,
option_unwrap,
options,
or,
or_patterns,
ord_cmp_method,
os_str_to_os_string,
os_string_as_os_str,
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_const_add_overflow,
panic_const_async_fn_resumed,
panic_const_async_fn_resumed_panic,
panic_const_async_gen_fn_resumed,
panic_const_async_gen_fn_resumed_panic,
panic_const_coroutine_resumed,
panic_const_coroutine_resumed_panic,
panic_const_div_by_zero,
panic_const_div_overflow,
panic_const_gen_fn_none,
panic_const_gen_fn_none_panic,
panic_const_mul_overflow,
panic_const_neg_overflow,
panic_const_rem_by_zero,
panic_const_rem_overflow,
panic_const_shl_overflow,
panic_const_shr_overflow,
panic_const_sub_overflow,
panic_fmt,
panic_handler,
panic_impl,
panic_implementation,
panic_in_cleanup,
panic_info,
panic_location,
panic_misaligned_pointer_dereference,
panic_nounwind,
panic_runtime,
panic_str_2015,
panic_unwind,
panicking,
param_attrs,
parent_label,
partial_cmp,
partial_ord,
passes,
pat,
pat_param,
patchable_function_entry,
path,
path_main_separator,
path_to_pathbuf,
pathbuf_as_path,
pattern_complexity,
pattern_parentheses,
pattern_type,
pattern_types,
permissions_from_mode,
phantom_data,
pic,
pie,
pin,
pin_ergonomics,
platform_intrinsics,
plugin,
plugin_registrar,
plugins,
pointee,
pointee_trait,
pointer,
pointer_like,
poll,
poll_next,
post_dash_lto: "post-lto",
postfix_match,
powerpc_target_feature,
powf128,
powf16,
powf32,
powf64,
powif128,
powif16,
powif32,
powif64,
pre_dash_lto: "pre-lto",
precise_capturing,
precise_capturing_in_traits,
precise_pointer_size_matching,
pref_align_of,
prefetch_read_data,
prefetch_read_instruction,
prefetch_write_data,
prefetch_write_instruction,
prefix_nops,
preg,
prelude,
prelude_import,
preserves_flags,
prfchw_target_feature,
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,
process_exit,
profiler_builtins,
profiler_runtime,
ptr,
ptr_cast,
ptr_cast_const,
ptr_cast_mut,
ptr_const_is_null,
ptr_copy,
ptr_copy_nonoverlapping,
ptr_eq,
ptr_from_ref,
ptr_guaranteed_cmp,
ptr_is_null,
ptr_mask,
ptr_metadata,
ptr_null,
ptr_null_mut,
ptr_offset_from,
ptr_offset_from_unsigned,
ptr_read,
ptr_read_unaligned,
ptr_read_volatile,
ptr_replace,
ptr_slice_from_raw_parts,
ptr_slice_from_raw_parts_mut,
ptr_swap,
ptr_swap_nonoverlapping,
ptr_unique,
ptr_write,
ptr_write_bytes,
ptr_write_unaligned,
ptr_write_volatile,
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_pat_eat_one_layer_2024,
ref_pat_eat_one_layer_2024_structural,
ref_pat_everywhere,
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,
result_ffi_guarantees,
result_ok_method,
resume,
return_position_impl_trait_in_trait,
return_type_notation,
rhs,
rintf128,
rintf16,
rintf32,
rintf64,
riscv_target_feature,
rlib,
ropi,
ropi_rwpi: "ropi-rwpi",
rotate_left,
rotate_right,
roundevenf128,
roundevenf16,
roundevenf32,
roundevenf64,
roundf128,
roundf16,
roundf32,
roundf64,
rt,
rtm_target_feature,
rust,
rust_2015,
rust_2018,
rust_2018_preview,
rust_2021,
rust_2024,
rust_analyzer,
rust_begin_unwind,
rust_cold_cc,
rust_eh_catch_typeinfo,
rust_eh_personality,
rust_logo,
rustc,
rustc_abi,
rustc_allocator,
rustc_allocator_zeroed,
rustc_allow_const_fn_unstable,
rustc_allow_incoherent_impl,
rustc_allowed_through_unstable_modules,
rustc_attrs,
rustc_autodiff,
rustc_box,
rustc_builtin_macro,
rustc_capture_analysis,
rustc_clean,
rustc_coherence_is_core,
rustc_coinductive,
rustc_confusables,
rustc_const_panic_str,
rustc_const_stable,
rustc_const_unstable,
rustc_conversion_suggestion,
rustc_deallocator,
rustc_def_path,
rustc_default_body_unstable,
rustc_deny_explicit_impl,
rustc_deprecated_safe_2024,
rustc_diagnostic_item,
rustc_diagnostic_macros,
rustc_dirty,
rustc_do_not_const_check,
rustc_doc_primitive,
rustc_driver,
rustc_dummy,
rustc_dump_def_parents,
rustc_dump_item_bounds,
rustc_dump_predicates,
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_hidden_type_of_opaques,
rustc_if_this_changed,
rustc_inherit_overflow_checks,
rustc_insignificant_dtor,
rustc_intrinsic,
rustc_intrinsic_must_be_overridden,
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_lint_untracked_query_information,
rustc_macro_transparency,
rustc_main,
rustc_mir,
rustc_must_implement_one_of,
rustc_never_returns_null_ptr,
rustc_never_type_options,
rustc_no_mir_inline,
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_preserve_ub_checks,
rustc_private,
rustc_proc_macro_decls,
rustc_promotable,
rustc_pub_transparent,
rustc_reallocator,
rustc_regions,
rustc_reservation_impl,
rustc_runtime,
rustc_safe_intrinsic,
rustc_serialize,
rustc_skip_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,
rustc_variance_of_opaques,
rustdoc,
rustdoc_internals,
rustdoc_missing_doc_code_examples,
rustfmt,
rvalue_static_promotion,
rwpi,
s,
s390x_target_feature,
safety,
sanitize,
sanitizer_cfi_generalize_pointers,
sanitizer_cfi_normalize_integers,
sanitizer_runtime,
saturating_add,
saturating_div,
saturating_sub,
select_unpredictable,
self_in_typedefs,
self_struct_ctor,
semitransparent,
sha512_sm_x86,
shadow_call_stack,
shallow,
shl,
shl_assign,
shorter_tail_lifetimes,
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_ctpop,
simd_cttz,
simd_div,
simd_eq,
simd_expose_provenance,
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_fsin,
simd_fsqrt,
simd_gather,
simd_ge,
simd_gt,
simd_insert,
simd_le,
simd_lt,
simd_masked_load,
simd_masked_store,
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_min,
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_shuffle_generic,
simd_sub,
simd_trunc,
simd_with_exposed_provenance,
simd_xor,
since,
sinf128,
sinf16,
sinf32,
sinf64,
size,
size_of,
size_of_val,
sized,
skip,
slice,
slice_from_raw_parts,
slice_from_raw_parts_mut,
slice_into_vec,
slice_iter,
slice_len_fn,
slice_patterns,
slicing_syntax,
soft,
specialization,
speed,
spotlight,
sqrtf128,
sqrtf16,
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_chars,
str_ends_with,
str_from_utf8,
str_from_utf8_mut,
str_from_utf8_unchecked,
str_from_utf8_unchecked_mut,
str_len,
str_split_whitespace,
str_starts_with,
str_trim,
str_trim_end,
str_trim_start,
strict_provenance,
string_as_mut_str,
string_as_str,
string_deref_patterns,
string_from_utf8,
string_insert_str,
string_new,
string_push_str,
stringify,
struct_field_attributes,
struct_inherit,
struct_variant,
structural_match,
structural_peq,
sub,
sub_assign,
sub_with_overflow,
suggestion,
surface_async_drop_in_place,
sym,
sync,
synthetic,
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,
three_way_compare,
thumb2,
thumb_mode: "thumb-mode",
time,
tmm_reg,
to_owned_method,
to_string,
to_string_method,
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,
truncf128,
truncf16,
truncf32,
truncf64,
try_blocks,
try_capture,
try_from,
try_from_fn,
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_ir_inherent,
type_length_limit,
type_macros,
type_name,
type_privacy_lints,
typed_swap,
u128,
u128_legacy_const_max,
u128_legacy_const_min,
u128_legacy_fn_max_value,
u128_legacy_fn_min_value,
u128_legacy_mod,
u16,
u16_legacy_const_max,
u16_legacy_const_min,
u16_legacy_fn_max_value,
u16_legacy_fn_min_value,
u16_legacy_mod,
u32,
u32_legacy_const_max,
u32_legacy_const_min,
u32_legacy_fn_max_value,
u32_legacy_fn_min_value,
u32_legacy_mod,
u64,
u64_legacy_const_max,
u64_legacy_const_min,
u64_legacy_fn_max_value,
u64_legacy_fn_min_value,
u64_legacy_mod,
u8,
u8_legacy_const_max,
u8_legacy_const_min,
u8_legacy_fn_max_value,
u8_legacy_fn_min_value,
u8_legacy_mod,
ub_checks,
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,
unlikely,
unmarked_api,
unnamed_fields,
unpin,
unqualified_local_imports,
unreachable,
unreachable_2015,
unreachable_2015_macro,
unreachable_2021,
unreachable_code,
unreachable_display,
unreachable_macro,
unrestricted_attribute_tokens,
unsafe_attributes,
unsafe_block_in_unsafe_fn,
unsafe_cell,
unsafe_cell_raw_get,
unsafe_extern_blocks,
unsafe_no_drop_flag,
unsafe_pin_internals,
unsize,
unsized_const_param_ty,
unsized_const_params,
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,
usize_legacy_const_max,
usize_legacy_const_min,
usize_legacy_fn_max_value,
usize_legacy_fn_min_value,
usize_legacy_mod,
va_arg,
va_copy,
va_end,
va_list,
va_start,
val,
validity,
values,
var,
variant_count,
vec,
vec_as_mut_slice,
vec_as_slice,
vec_from_elem,
vec_is_empty,
vec_macro,
vec_new,
vec_pop,
vec_with_capacity,
vecdeque_iter,
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,
wasip2,
wasm_abi,
wasm_import_module,
wasm_target_feature,
while_let,
windows,
windows_subsystem,
with_negative_coherence,
wrapping_add,
wrapping_div,
wrapping_mul,
wrapping_rem,
wrapping_rem_euclid,
wrapping_sub,
wreg,
write_bytes,
write_macro,
write_str,
write_via_move,
writeln_macro,
x86_amx_intrinsics,
x87_reg,
xer,
xmm_reg,
xop_target_feature,
yeet_desugar_details,
yeet_expr,
yes,
yield_expr,
ymm_reg,
zfh,
zfhmin,
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 {
#[inline]
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! {
#[orderable]
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<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()
}
}
impl StableCompare for Symbol {
const CAN_USE_UNSTABLE_SORT: bool = true;
fn stable_cmp(&self, other: &Self) -> std::cmp::Ordering {
self.as_str().cmp(other.as_str())
}
}
pub(crate) struct Interner(Lock<InternerInner>);
// The `&'static str`s in this type actually point into the arena.
//
// 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.
struct InternerInner {
arena: DroplessArena,
strings: FxIndexSet<&'static str>,
}
impl Interner {
fn prefill(init: &[&'static str]) -> Self {
Interner(Lock::new(InternerInner {
arena: Default::default(),
strings: init.iter().copied().collect(),
}))
}
#[inline]
fn intern(&self, string: &str) -> Symbol {
let mut inner = self.0.lock();
if let Some(idx) = inner.strings.get_index_of(string) {
return Symbol::new(idx as u32);
}
let string: &str = inner.arena.alloc_str(string);
// 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) };
// 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.
let (idx, is_new) = inner.strings.insert_full(string);
debug_assert!(is_new); // due to the get_index_of check above
Symbol::new(idx as u32)
}
/// 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.get_index(symbol.0.as_usize()).unwrap()
}
}
// 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 {
// Used from a macro in `librustc_feature/accepted.rs`
use super::Symbol;
pub use super::kw::MacroRules as macro_rules;
#[doc(inline)]
pub use super::sym_generated::*;
/// 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 + itoa::Integer>(n: N) -> Symbol {
if let Result::Ok(idx) = n.try_into() {
if idx < 10 {
return Symbol::new(super::SYMBOL_DIGITS_BASE + idx as u32);
}
}
let mut buffer = itoa::Buffer::new();
let printed = buffer.format(n);
Symbol::intern(printed)
}
}
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 Copy + FnOnce() -> Edition) -> bool {
self == kw::Try && edition().at_least_rust_2018()
|| self == kw::Gen && edition().at_least_rust_2024()
}
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()
}
}
/// An iterator over all the keywords in Rust.
#[derive(Copy, Clone)]
pub struct AllKeywords {
curr_idx: u32,
end_idx: u32,
}
impl AllKeywords {
/// Initialize a new iterator over all the keywords.
///
/// *Note:* Please update this if a new keyword is added beyond the current
/// range.
pub fn new() -> Self {
AllKeywords { curr_idx: kw::Empty.as_u32(), end_idx: kw::Yeet.as_u32() }
}
/// Collect all the keywords in a given edition into a vector.
pub fn collect_used(&self, edition: impl Copy + FnOnce() -> Edition) -> Vec<Symbol> {
self.filter(|&keyword| {
keyword.is_used_keyword_always() || keyword.is_used_keyword_conditional(edition)
})
.collect()
}
}
impl Iterator for AllKeywords {
type Item = Symbol;
fn next(&mut self) -> Option<Self::Item> {
if self.curr_idx <= self.end_idx {
let keyword = Symbol::new(self.curr_idx);
self.curr_idx += 1;
Some(keyword)
} else {
None
}
}
}