Crate rustc_ap_rustc_feature

Feature gates

This crate declares the set of past and present unstable features in the compiler. Feature gate checking itself is done in librustc_ast_passes/feature_gate.rs at the moment.

Features are enabled in programs via the crate-level attributes of #![feature(...)] with a comma-separated list of features.

For the purpose of future feature-tracking, once a feature gate is added, even if it is stabilized or removed, do not remove it. Instead, move the symbol to the accepted or removed modules respectively.

Structs

AttributeTemplate	A template that the attribute input must match. Only top-level shape (#[attr] vs #[attr(...)] vs #[attr = ...]) is considered now.
BUILTIN_ATTRIBUTE_MAP
Feature
Features	A set of features to be used by later passes.

Enums

AttributeGate
AttributeType
GateIssue
Stability
State
UnstableFeatures

Constants

ACCEPTED_FEATURES	Those language feature has since been Accepted (it was once Active)
ACTIVE_FEATURES	Represents active features that are currently being implemented or currently being considered for addition/removal.
BUILTIN_ATTRIBUTES	Attributes that have a special meaning to rustc or rustdoc.
INCOMPLETE_FEATURES	Some features are known to be incomplete and using them is likely to have unanticipated results, such as compiler crashes. We warn the user about these to alert them.
REMOVED_FEATURES	Represents unstable features which have since been removed (it was once Active)
STABLE_REMOVED_FEATURES	Represents stable features which have since been removed (it was once Accepted)

Functions

deprecated_attributes
find_feature_issue
find_gated_cfg	Find a gated cfg determined by the predicate which is given the cfg's name.
is_builtin_attr_name

Type Definitions

BuiltinAttribute
GatedCfg