1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
use crate::context::{EarlyContext, LateContext};

use rustc_session::lint::builtin::HardwiredLints;
use rustc_session::lint::LintPass;

#[macro_export]
macro_rules! late_lint_methods {
    ($macro:path, $args:tt) => (
        $macro!($args, [
            fn check_body(a: &rustc_hir::Body<'tcx>);
            fn check_body_post(a: &rustc_hir::Body<'tcx>);
            fn check_crate();
            fn check_crate_post();
            fn check_mod(a: &'tcx rustc_hir::Mod<'tcx>, b: rustc_hir::HirId);
            fn check_foreign_item(a: &'tcx rustc_hir::ForeignItem<'tcx>);
            fn check_item(a: &'tcx rustc_hir::Item<'tcx>);
            fn check_item_post(a: &'tcx rustc_hir::Item<'tcx>);
            fn check_local(a: &'tcx rustc_hir::LetStmt<'tcx>);
            fn check_block(a: &'tcx rustc_hir::Block<'tcx>);
            fn check_block_post(a: &'tcx rustc_hir::Block<'tcx>);
            fn check_stmt(a: &'tcx rustc_hir::Stmt<'tcx>);
            fn check_arm(a: &'tcx rustc_hir::Arm<'tcx>);
            fn check_pat(a: &'tcx rustc_hir::Pat<'tcx>);
            fn check_expr(a: &'tcx rustc_hir::Expr<'tcx>);
            fn check_expr_post(a: &'tcx rustc_hir::Expr<'tcx>);
            fn check_ty(a: &'tcx rustc_hir::Ty<'tcx>);
            fn check_generic_param(a: &'tcx rustc_hir::GenericParam<'tcx>);
            fn check_generics(a: &'tcx rustc_hir::Generics<'tcx>);
            fn check_poly_trait_ref(a: &'tcx rustc_hir::PolyTraitRef<'tcx>);
            fn check_fn(
                a: rustc_hir::intravisit::FnKind<'tcx>,
                b: &'tcx rustc_hir::FnDecl<'tcx>,
                c: &'tcx rustc_hir::Body<'tcx>,
                d: rustc_span::Span,
                e: rustc_span::def_id::LocalDefId);
            fn check_trait_item(a: &'tcx rustc_hir::TraitItem<'tcx>);
            fn check_impl_item(a: &'tcx rustc_hir::ImplItem<'tcx>);
            fn check_impl_item_post(a: &'tcx rustc_hir::ImplItem<'tcx>);
            fn check_struct_def(a: &'tcx rustc_hir::VariantData<'tcx>);
            fn check_field_def(a: &'tcx rustc_hir::FieldDef<'tcx>);
            fn check_variant(a: &'tcx rustc_hir::Variant<'tcx>);
            fn check_path(a: &rustc_hir::Path<'tcx>, b: rustc_hir::HirId);
            fn check_attribute(a: &'tcx rustc_ast::Attribute);
            fn check_attributes(a: &'tcx [rustc_ast::Attribute]);
            fn check_attributes_post(a: &'tcx [rustc_ast::Attribute]);
        ]);
    )
}

/// Trait for types providing lint checks.
///
/// Each `check` method checks a single syntax node, and should not
/// invoke methods recursively (unlike `Visitor`). By default they
/// do nothing.
//
// FIXME: eliminate the duplication with `Visitor`. But this also
// contains a few lint-specific methods with no equivalent in `Visitor`.

macro_rules! declare_late_lint_pass {
    ([], [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
        pub trait LateLintPass<'tcx>: LintPass {
            $(#[inline(always)] fn $name(&mut self, _: &LateContext<'tcx>, $(_: $arg),*) {})*
        }
    )
}

// Declare the `LateLintPass` trait, which contains empty default definitions
// for all the `check_*` methods.
late_lint_methods!(declare_late_lint_pass, []);

impl LateLintPass<'_> for HardwiredLints {}

#[macro_export]
macro_rules! expand_combined_late_lint_pass_method {
    ([$($pass:ident),*], $self: ident, $name: ident, $params:tt) => ({
        $($self.$pass.$name $params;)*
    })
}

#[macro_export]
macro_rules! expand_combined_late_lint_pass_methods {
    ($passes:tt, [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
        $(fn $name(&mut self, context: &$crate::LateContext<'tcx>, $($param: $arg),*) {
            $crate::expand_combined_late_lint_pass_method!($passes, self, $name, (context, $($param),*));
        })*
    )
}

/// Combines multiple lints passes into a single lint pass, at compile time,
/// for maximum speed. Each `check_foo` method in `$methods` within this pass
/// simply calls `check_foo` once per `$pass`. Compare with
/// `LateLintPassObjects`, which is similar, but combines lint passes at
/// runtime.
#[macro_export]
macro_rules! declare_combined_late_lint_pass {
    ([$v:vis $name:ident, [$($pass:ident: $constructor:expr,)*]], $methods:tt) => (
        #[allow(non_snake_case)]
        $v struct $name {
            $($pass: $pass,)*
        }

        impl $name {
            $v fn new() -> Self {
                Self {
                    $($pass: $constructor,)*
                }
            }

            $v fn get_lints() -> $crate::LintVec {
                let mut lints = Vec::new();
                $(lints.extend_from_slice(&$pass::get_lints());)*
                lints
            }
        }

        impl<'tcx> $crate::LateLintPass<'tcx> for $name {
            $crate::expand_combined_late_lint_pass_methods!([$($pass),*], $methods);
        }

        #[allow(rustc::lint_pass_impl_without_macro)]
        impl $crate::LintPass for $name {
            fn name(&self) -> &'static str {
                panic!()
            }
        }
    )
}

#[macro_export]
macro_rules! early_lint_methods {
    ($macro:path, $args:tt) => (
        $macro!($args, [
            fn check_param(a: &rustc_ast::Param);
            fn check_ident(a: rustc_span::symbol::Ident);
            fn check_crate(a: &rustc_ast::Crate);
            fn check_crate_post(a: &rustc_ast::Crate);
            fn check_item(a: &rustc_ast::Item);
            fn check_item_post(a: &rustc_ast::Item);
            fn check_local(a: &rustc_ast::Local);
            fn check_block(a: &rustc_ast::Block);
            fn check_stmt(a: &rustc_ast::Stmt);
            fn check_arm(a: &rustc_ast::Arm);
            fn check_pat(a: &rustc_ast::Pat);
            fn check_pat_post(a: &rustc_ast::Pat);
            fn check_expr(a: &rustc_ast::Expr);
            fn check_expr_post(a: &rustc_ast::Expr);
            fn check_ty(a: &rustc_ast::Ty);
            fn check_generic_arg(a: &rustc_ast::GenericArg);
            fn check_generic_param(a: &rustc_ast::GenericParam);
            fn check_generics(a: &rustc_ast::Generics);
            fn check_poly_trait_ref(a: &rustc_ast::PolyTraitRef);
            fn check_fn(
                a: rustc_ast::visit::FnKind<'_>,
                c: rustc_span::Span,
                d_: rustc_ast::NodeId);
            fn check_trait_item(a: &rustc_ast::AssocItem);
            fn check_impl_item(a: &rustc_ast::AssocItem);
            fn check_variant(a: &rustc_ast::Variant);
            fn check_attribute(a: &rustc_ast::Attribute);
            fn check_attributes(a: &[rustc_ast::Attribute]);
            fn check_attributes_post(a: &[rustc_ast::Attribute]);
            fn check_mac_def(a: &rustc_ast::MacroDef);
            fn check_mac(a: &rustc_ast::MacCall);

            fn enter_where_predicate(a: &rustc_ast::WherePredicate);
            fn exit_where_predicate(a: &rustc_ast::WherePredicate);
        ]);
    )
}

macro_rules! declare_early_lint_pass {
    ([], [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
        pub trait EarlyLintPass: LintPass {
            $(#[inline(always)] fn $name(&mut self, _: &EarlyContext<'_>, $(_: $arg),*) {})*
        }
    )
}

// Declare the `EarlyLintPass` trait, which contains empty default definitions
// for all the `check_*` methods.
early_lint_methods!(declare_early_lint_pass, []);

#[macro_export]
macro_rules! expand_combined_early_lint_pass_method {
    ([$($pass:ident),*], $self: ident, $name: ident, $params:tt) => ({
        $($self.$pass.$name $params;)*
    })
}

#[macro_export]
macro_rules! expand_combined_early_lint_pass_methods {
    ($passes:tt, [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
        $(fn $name(&mut self, context: &$crate::EarlyContext<'_>, $($param: $arg),*) {
            $crate::expand_combined_early_lint_pass_method!($passes, self, $name, (context, $($param),*));
        })*
    )
}

/// Combines multiple lints passes into a single lint pass, at compile time,
/// for maximum speed. Each `check_foo` method in `$methods` within this pass
/// simply calls `check_foo` once per `$pass`. Compare with
/// `EarlyLintPassObjects`, which is similar, but combines lint passes at
/// runtime.
#[macro_export]
macro_rules! declare_combined_early_lint_pass {
    ([$v:vis $name:ident, [$($pass:ident: $constructor:expr,)*]], $methods:tt) => (
        #[allow(non_snake_case)]
        $v struct $name {
            $($pass: $pass,)*
        }

        impl $name {
            $v fn new() -> Self {
                Self {
                    $($pass: $constructor,)*
                }
            }

            $v fn get_lints() -> $crate::LintVec {
                let mut lints = Vec::new();
                $(lints.extend_from_slice(&$pass::get_lints());)*
                lints
            }
        }

        impl $crate::EarlyLintPass for $name {
            $crate::expand_combined_early_lint_pass_methods!([$($pass),*], $methods);
        }

        #[allow(rustc::lint_pass_impl_without_macro)]
        impl $crate::LintPass for $name {
            fn name(&self) -> &'static str {
                panic!()
            }
        }
    )
}

/// A lint pass boxed up as a trait object.
pub(crate) type EarlyLintPassObject = Box<dyn EarlyLintPass + 'static>;
pub(crate) type LateLintPassObject<'tcx> = Box<dyn LateLintPass<'tcx> + 'tcx>;