Module cfg 

cfg and check-cfg configuration

This module contains the definition of Cfg and CheckCfg as well as the logic for creating the default configuration for a given Session.

It also contains the filling of the well known configs, which should ALWAYS be in sync with the default_configuration.

Adding a new cfg

Adding a new feature requires two new symbols one for the cfg itself and the second one for the unstable feature gate, those are defined in rustc_span::symbol.

As well as the following points,

• Add the activation logic in default_configuration
• Add the cfg to CheckCfg::fill_well_known (and related files), so that the compiler can know the cfg is expected
• Add the cfg in disallow_cfgs to disallow users from setting it via --cfg
• Add the feature gating in compiler/rustc_feature/src/builtin_attrs.rs

Re-exports

use std::hash::Hash; 🔒

use std::hash::Hash; 🔒

use std::iter; 🔒

use rustc_abi::Align; 🔒

use rustc_data_structures::fx::FxHashMap; 🔒

use rustc_data_structures::fx::FxHashSet; 🔒

use rustc_data_structures::fx::FxIndexSet; 🔒

use rustc_lint_defs::builtin::EXPLICIT_BUILTIN_CFGS_IN_FLAGS; 🔒

use rustc_span::Symbol; 🔒

use rustc_span::sym; 🔒

use rustc_target::spec::PanicStrategy; 🔒

use rustc_target::spec::RelocModel; 🔒

use rustc_target::spec::SanitizerSet; 🔒

use rustc_target::spec::Target; 🔒

use crate::config::CrateType; 🔒

use crate::config::FmtDebug; 🔒

use crate::Session; 🔒

use crate::diagnostics; 🔒

Structs

CheckCfg

The parsed --check-cfg options.

Enums

ExpectedValues

Functions

default_configuration 🔒

Generate the default configs for a given session

disallow_cfgs 🔒

Disallow builtin cfgs from the CLI.

Type Aliases

Cfg

The parsed --cfg options that define the compilation environment of the crate, used to drive conditional compilation.