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Commit 3641a37

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GuillaumeGomezGuillaumeGomez
committedOct 4, 2020
Enforce crate level attributes checks
·
1.86.01.49.0
1 parent 6ec2474 commit 3641a37

10 files changed

+377
-372
lines changed
 

‎compiler/rustc_passes/src/check_attr.rs

+31-3
Original file line numberDiff line numberDiff line change
@@ -19,8 +19,8 @@ use rustc_hir::{
1919
use rustc_hir::{MethodKind, Target};
2020
use rustc_session::lint::builtin::{CONFLICTING_REPR_HINTS, UNUSED_ATTRIBUTES};
2121
use rustc_session::parse::feature_err;
22-
use rustc_span::symbol::sym;
23-
use rustc_span::Span;
22+
use rustc_span::symbol::{sym, Symbol};
23+
use rustc_span::{Span, DUMMY_SP};
2424

2525
pub(crate) fn target_from_impl_item<'tcx>(
2626
tcx: TyCtxt<'tcx>,
@@ -821,17 +821,45 @@ fn is_c_like_enum(item: &Item<'_>) -> bool {
821821
}
822822
}
823823

824+
fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) {
825+
const ATTRS_TO_CHECK: &[Symbol] = &[
826+
sym::macro_export,
827+
sym::repr,
828+
sym::path,
829+
sym::automatically_derived,
830+
sym::start,
831+
sym::main,
832+
];
833+
834+
for attr in attrs {
835+
for attr_to_check in ATTRS_TO_CHECK {
836+
if tcx.sess.check_name(attr, *attr_to_check) {
837+
tcx.sess
838+
.struct_span_err(
839+
attr.span,
840+
&format!(
841+
"`{}` attribute cannot be used at crate level",
842+
attr_to_check.to_ident_string()
843+
),
844+
)
845+
.emit();
846+
}
847+
}
848+
}
849+
}
850+
824851
fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
825852
tcx.hir()
826853
.visit_item_likes_in_module(module_def_id, &mut CheckAttrVisitor { tcx }.as_deep_visitor());
827854
if module_def_id.is_top_level_module() {
828855
CheckAttrVisitor { tcx }.check_attributes(
829856
CRATE_HIR_ID,
830857
tcx.hir().krate_attrs(),
831-
&tcx.hir().span(CRATE_HIR_ID),
858+
&DUMMY_SP,
832859
Target::Mod,
833860
None,
834861
);
862+
check_invalid_crate_level_attr(tcx, tcx.hir().krate_attrs());
835863
}
836864
}
837865

‎compiler/rustc_passes/src/entry.rs

+26-18
Original file line numberDiff line numberDiff line change
@@ -78,29 +78,38 @@ fn entry_fn(tcx: TyCtxt<'_>, cnum: CrateNum) -> Option<(LocalDefId, EntryFnType)
7878
// Beware, this is duplicated in `librustc_builtin_macros/test_harness.rs`
7979
// (with `ast::Item`), so make sure to keep them in sync.
8080
fn entry_point_type(sess: &Session, item: &Item<'_>, at_root: bool) -> EntryPointType {
81-
match item.kind {
82-
ItemKind::Fn(..) => {
83-
if sess.contains_name(&item.attrs, sym::start) {
84-
EntryPointType::Start
85-
} else if sess.contains_name(&item.attrs, sym::main) {
86-
EntryPointType::MainAttr
87-
} else if item.ident.name == sym::main {
88-
if at_root {
89-
// This is a top-level function so can be `main`.
90-
EntryPointType::MainNamed
91-
} else {
92-
EntryPointType::OtherMain
93-
}
94-
} else {
95-
EntryPointType::None
96-
}
81+
if sess.contains_name(&item.attrs, sym::start) {
82+
EntryPointType::Start
83+
} else if sess.contains_name(&item.attrs, sym::main) {
84+
EntryPointType::MainAttr
85+
} else if item.ident.name == sym::main {
86+
if at_root {
87+
// This is a top-level function so can be `main`.
88+
EntryPointType::MainNamed
89+
} else {
90+
EntryPointType::OtherMain
9791
}
98-
_ => EntryPointType::None,
92+
} else {
93+
EntryPointType::None
9994
}
10095
}
10196

97+
fn throw_attr_err(sess: &Session, span: Span, attr: &str) {
98+
sess.struct_span_err(span, &format!("`{}` attribute can only be used on functions", attr))
99+
.emit();
100+
}
101+
102102
fn find_item(item: &Item<'_>, ctxt: &mut EntryContext<'_, '_>, at_root: bool) {
103103
match entry_point_type(&ctxt.session, item, at_root) {
104+
EntryPointType::None => (),
105+
_ if !matches!(item.kind, ItemKind::Fn(..)) => {
106+
if let Some(attr) = ctxt.session.find_by_name(item.attrs, sym::start) {
107+
throw_attr_err(&ctxt.session, attr.span, "start");
108+
}
109+
if let Some(attr) = ctxt.session.find_by_name(item.attrs, sym::main) {
110+
throw_attr_err(&ctxt.session, attr.span, "main");
111+
}
112+
}
104113
EntryPointType::MainNamed => {
105114
if ctxt.main_fn.is_none() {
106115
ctxt.main_fn = Some((item.hir_id, item.span));
@@ -137,7 +146,6 @@ fn find_item(item: &Item<'_>, ctxt: &mut EntryContext<'_, '_>, at_root: bool) {
137146
.emit();
138147
}
139148
}
140-
EntryPointType::None => (),
141149
}
142150
}
143151

‎compiler/rustc_session/src/lint/builtin.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -518,7 +518,7 @@ declare_lint! {
518518
/// ### Example
519519
///
520520
/// ```rust
521-
/// #![macro_export]
521+
/// #![ignore]
522522
/// ```
523523
///
524524
/// {{produces}}

‎src/test/rustdoc-ui/doc-alias-crate-level.rs

+4-1
Original file line numberDiff line numberDiff line change
@@ -1,3 +1,6 @@
11
#![feature(doc_alias)]
22

3-
#![doc(alias = "shouldn't work!")] //~ ERROR
3+
#![doc(alias = "crate-level-not-working")] //~ ERROR
4+
5+
#[doc(alias = "shouldn't work!")] //~ ERROR
6+
pub fn foo() {}

‎src/test/rustdoc-ui/doc-alias-crate-level.stderr

+9-3
Original file line numberDiff line numberDiff line change
@@ -1,8 +1,14 @@
1+
error: '\'' character isn't allowed in `#[doc(alias = "...")]`
2+
--> $DIR/doc-alias-crate-level.rs:5:7
3+
|
4+
LL | #[doc(alias = "shouldn't work!")]
5+
| ^^^^^^^^^^^^^^^^^^^^^^^^^
6+
17
error: `#![doc(alias = "...")]` isn't allowed as a crate level attribute
28
--> $DIR/doc-alias-crate-level.rs:3:8
39
|
4-
LL | #![doc(alias = "shouldn't work!")]
5-
| ^^^^^^^^^^^^^^^^^^^^^^^^^
10+
LL | #![doc(alias = "crate-level-not-working")]
11+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
612

7-
error: aborting due to previous error
13+
error: aborting due to 2 previous errors
814

‎src/test/ui/doc-alias-crate-level.stderr

+1-1
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
error: `#![doc(alias = "...")]` isn't allowed as a crate level attribute
1+
error: '\'' character isn't allowed in `#[doc(alias = "...")]`
22
--> $DIR/doc-alias-crate-level.rs:7:8
33
|
44
LL | #![doc(alias = "shouldn't work!")]

‎src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs-error.rs

+45-9
Original file line numberDiff line numberDiff line change
@@ -1,3 +1,6 @@
1+
//~ NOTE: not an `extern crate` item
2+
//~^ NOTE: not a function or static
3+
//~^^ NOTE: not a function or closure
14
// This is testing whether various builtin attributes signals an
25
// error or warning when put in "weird" places.
36
//
@@ -7,22 +10,19 @@
710

811
// ignore-tidy-linelength
912

10-
#![deny(unused_attributes)]
11-
//~^ NOTE not a function or static
12-
//~^^ NOTE the lint level is defined here
13-
//~^^^ NOTE not an `extern crate` item
14-
//~^^^^ NOTE not a function or static
15-
//~^^^^^ NOTE not a function or closure
16-
1713
#![macro_export]
14+
//~^ ERROR: `macro_export` attribute cannot be used at crate level
1815
#![main]
16+
//~^ ERROR: `main` attribute cannot be used at crate level
1917
#![start]
18+
//~^ ERROR: `start` attribute cannot be used at crate level
2019
#![repr()]
20+
//~^ ERROR: `repr` attribute cannot be used at crate level
2121
#![path = "3800"]
22+
//~^ ERROR: `path` attribute cannot be used at crate level
2223
#![automatically_derived]
24+
//~^ ERROR: `automatically_derived` attribute cannot be used at crate level
2325
#![no_mangle]
24-
//~^ ERROR attribute should be applied to a function or static
25-
//~^^ WARN
2626
#![no_link]
2727
//~^ ERROR: attribute should be applied to an `extern crate` item
2828
#![export_name = "2200"]
@@ -107,4 +107,40 @@ mod export_name {
107107
//~| NOTE not a function or static
108108
}
109109

110+
#[main]
111+
//~^ ERROR: `main` attribute can only be used on functions
112+
mod main {
113+
mod inner { #![main] }
114+
//~^ ERROR: `main` attribute can only be used on functions
115+
116+
// for `fn f()` case, see feature-gate-main.rs
117+
118+
#[main] struct S;
119+
//~^ ERROR: `main` attribute can only be used on functions
120+
121+
#[main] type T = S;
122+
//~^ ERROR: `main` attribute can only be used on functions
123+
124+
#[main] impl S { }
125+
//~^ ERROR: `main` attribute can only be used on functions
126+
}
127+
128+
#[start]
129+
//~^ ERROR: `start` attribute can only be used on functions
130+
mod start {
131+
mod inner { #![start] }
132+
//~^ ERROR: `start` attribute can only be used on functions
133+
134+
// for `fn f()` case, see feature-gate-start.rs
135+
136+
#[start] struct S;
137+
//~^ ERROR: `start` attribute can only be used on functions
138+
139+
#[start] type T = S;
140+
//~^ ERROR: `start` attribute can only be used on functions
141+
142+
#[start] impl S { }
143+
//~^ ERROR: `start` attribute can only be used on functions
144+
}
145+
110146
fn main() {}

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