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Auto merge of #54037 - pietroalbini:beta-backports, r=pietroalbini
[beta] Rollup backports Merged and approved: * #53893: Validate syntax of `cfg` attributes r? @ghost
2 parents 309e21c + c26cd04 commit edfc72b

11 files changed

+219
-33
lines changed

‎src/librustc/session/config.rs

+25-14
Original file line numberDiff line numberDiff line change
@@ -28,7 +28,7 @@ use rustc_data_structures::stable_hasher::ToStableHashKey;
2828
use lint;
2929
use middle::cstore;
3030

31-
use syntax::ast::{self, IntTy, UintTy};
31+
use syntax::ast::{self, IntTy, UintTy, MetaItemKind};
3232
use syntax::codemap::{FileName, FilePathMapping};
3333
use syntax::edition::{Edition, EDITION_NAME_LIST, DEFAULT_EDITION};
3434
use syntax::parse::token;
@@ -1746,22 +1746,33 @@ pub fn parse_cfgspecs(cfgspecs: Vec<String>) -> ast::CrateConfig {
17461746
let mut parser =
17471747
parse::new_parser_from_source_str(&sess, FileName::CfgSpec, s.to_string());
17481748

1749-
let meta_item = panictry!(parser.parse_meta_item());
1749+
macro_rules! error {($reason: expr) => {
1750+
early_error(ErrorOutputType::default(),
1751+
&format!(concat!("invalid `--cfg` argument: `{}` (", $reason, ")"), s));
1752+
}}
17501753

1751-
if parser.token != token::Eof {
1752-
early_error(
1753-
ErrorOutputType::default(),
1754-
&format!("invalid --cfg argument: {}", s),
1755-
)
1756-
} else if meta_item.is_meta_item_list() {
1757-
let msg = format!(
1758-
"invalid predicate in --cfg command line argument: `{}`",
1759-
meta_item.ident
1760-
);
1761-
early_error(ErrorOutputType::default(), &msg)
1754+
match &mut parser.parse_meta_item() {
1755+
Ok(meta_item) if parser.token == token::Eof => {
1756+
if meta_item.ident.segments.len() != 1 {
1757+
error!("argument key must be an identifier");
1758+
}
1759+
match &meta_item.node {
1760+
MetaItemKind::List(..) => {
1761+
error!(r#"expected `key` or `key="value"`"#);
1762+
}
1763+
MetaItemKind::NameValue(lit) if !lit.node.is_str() => {
1764+
error!("argument value must be a string");
1765+
}
1766+
MetaItemKind::NameValue(..) | MetaItemKind::Word => {
1767+
return (meta_item.name(), meta_item.value_str());
1768+
}
1769+
}
1770+
}
1771+
Ok(..) => {}
1772+
Err(err) => err.cancel(),
17621773
}
17631774

1764-
(meta_item.name(), meta_item.value_str())
1775+
error!(r#"expected `key` or `key="value"`"#);
17651776
})
17661777
.collect::<ast::CrateConfig>()
17671778
}

‎src/libsyntax/attr/builtin.rs

+15-1
Original file line numberDiff line numberDiff line change
@@ -435,7 +435,21 @@ pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Feat
435435
if let (Some(feats), Some(gated_cfg)) = (features, GatedCfg::gate(cfg)) {
436436
gated_cfg.check_and_emit(sess, feats);
437437
}
438-
sess.config.contains(&(cfg.name(), cfg.value_str()))
438+
let error = |span, msg| { sess.span_diagnostic.span_err(span, msg); true };
439+
if cfg.ident.segments.len() != 1 {
440+
return error(cfg.ident.span, "`cfg` predicate key must be an identifier");
441+
}
442+
match &cfg.node {
443+
MetaItemKind::List(..) => {
444+
error(cfg.span, "unexpected parentheses after `cfg` predicate key")
445+
}
446+
MetaItemKind::NameValue(lit) if !lit.node.is_str() => {
447+
error(lit.span, "literal in `cfg` predicate value must be a string")
448+
}
449+
MetaItemKind::NameValue(..) | MetaItemKind::Word => {
450+
sess.config.contains(&(cfg.name(), cfg.value_str()))
451+
}
452+
}
439453
})
440454
}
441455

‎src/libsyntax/config.rs

+32-12
Original file line numberDiff line numberDiff line change
@@ -123,25 +123,45 @@ impl<'a> StripUnconfigured<'a> {
123123
return false;
124124
}
125125

126-
let mis = if !is_cfg(attr) {
126+
if !is_cfg(attr) {
127127
return true;
128-
} else if let Some(mis) = attr.meta_item_list() {
129-
mis
128+
}
129+
130+
let error = |span, msg, suggestion: &str| {
131+
let mut err = self.sess.span_diagnostic.struct_span_err(span, msg);
132+
if !suggestion.is_empty() {
133+
err.span_suggestion(span, "expected syntax is", suggestion.into());
134+
}
135+
err.emit();
136+
true
137+
};
138+
139+
let meta_item = if let Some(meta_item) = attr.meta() {
140+
meta_item
130141
} else {
131-
return true;
142+
// Not a well-formed meta-item. Why? We don't know.
143+
return error(attr.span, "`cfg` is not a well-formed meta-item",
144+
"#[cfg(/* predicate */)]");
145+
};
146+
let nested_meta_items = if let Some(nested_meta_items) = meta_item.meta_item_list() {
147+
nested_meta_items
148+
} else {
149+
return error(meta_item.span, "`cfg` is not followed by parentheses",
150+
"cfg(/* predicate */)");
132151
};
133152

134-
if mis.len() != 1 {
135-
self.sess.span_diagnostic.span_err(attr.span, "expected 1 cfg-pattern");
136-
return true;
153+
if nested_meta_items.is_empty() {
154+
return error(meta_item.span, "`cfg` predicate is not specified", "");
155+
} else if nested_meta_items.len() > 1 {
156+
return error(nested_meta_items.last().unwrap().span,
157+
"multiple `cfg` predicates are specified", "");
137158
}
138159

139-
if !mis[0].is_meta_item() {
140-
self.sess.span_diagnostic.span_err(mis[0].span, "unexpected literal");
141-
return true;
160+
match nested_meta_items[0].meta_item() {
161+
Some(meta_item) => attr::cfg_matches(meta_item, self.sess, self.features),
162+
None => error(nested_meta_items[0].span,
163+
"`cfg` predicate key cannot be a literal", ""),
142164
}
143-
144-
attr::cfg_matches(mis[0].meta_item().unwrap(), self.sess, self.features)
145165
})
146166
}
147167

‎src/test/compile-fail/cfg-empty-codemap.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -12,7 +12,7 @@
1212

1313
// compile-flags: --cfg ""
1414

15-
// error-pattern: expected identifier, found
15+
// error-pattern: invalid `--cfg` argument
1616

1717
pub fn main() {
1818
}

‎src/test/ui/cfg-arg-invalid-1.rs

+13
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,13 @@
1+
// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// compile-flags: --cfg a(b=c)
12+
// error-pattern: invalid `--cfg` argument: `a(b=c)` (expected `key` or `key="value"`)
13+
fn main() {}

‎src/test/compile-fail/cfg-arg-invalid.rs ‎src/test/ui/cfg-arg-invalid-2.rs

+2-2
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
1+
// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
22
// file at the top-level directory of this distribution and at
33
// http://rust-lang.org/COPYRIGHT.
44
//
@@ -9,5 +9,5 @@
99
// except according to those terms.
1010

1111
// compile-flags: --cfg a{b}
12-
// error-pattern: invalid --cfg argument: a{b}
12+
// error-pattern: invalid `--cfg` argument: `a{b}` (expected `key` or `key="value"`)
1313
fn main() {}

‎src/test/ui/cfg-arg-invalid-3.rs

+13
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,13 @@
1+
// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// compile-flags: --cfg a::b
12+
// error-pattern: invalid `--cfg` argument: `a::b` (argument key must be an identifier)
13+
fn main() {}

‎src/test/ui/issue-31495.rs ‎src/test/ui/cfg-arg-invalid-4.rs

+3-3
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
1+
// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
22
// file at the top-level directory of this distribution and at
33
// http://rust-lang.org/COPYRIGHT.
44
//
@@ -8,6 +8,6 @@
88
// option. This file may not be copied, modified, or distributed
99
// except according to those terms.
1010

11-
// compile-flags: --cfg foo(bar)
12-
// error-pattern: invalid predicate in --cfg command line argument: `foo`
11+
// compile-flags: --cfg a(b)
12+
// error-pattern: invalid `--cfg` argument: `a(b)` (expected `key` or `key="value"`)
1313
fn main() {}

‎src/test/ui/cfg-arg-invalid-5.rs

+13
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,13 @@
1+
// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// compile-flags: --cfg a=10
12+
// error-pattern: invalid `--cfg` argument: `a=10` (argument value must be a string)
13+
fn main() {}

‎src/test/ui/cfg-attr-syntax-validation.rs

+42
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,42 @@
1+
// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
#[cfg] //~ ERROR `cfg` is not followed by parentheses
12+
struct S1;
13+
14+
#[cfg = 10] //~ ERROR `cfg` is not followed by parentheses
15+
struct S2;
16+
17+
#[cfg()] //~ ERROR `cfg` predicate is not specified
18+
struct S3;
19+
20+
#[cfg(a, b)] //~ ERROR multiple `cfg` predicates are specified
21+
struct S4;
22+
23+
#[cfg("str")] //~ ERROR `cfg` predicate key cannot be a literal
24+
struct S5;
25+
26+
#[cfg(a::b)] //~ ERROR `cfg` predicate key must be an identifier
27+
struct S6;
28+
29+
#[cfg(a())] //~ ERROR invalid predicate `a`
30+
struct S7;
31+
32+
#[cfg(a = 10)] //~ ERROR literal in `cfg` predicate value must be a string
33+
struct S8;
34+
35+
macro_rules! generate_s9 {
36+
($expr: expr) => {
37+
#[cfg(feature = $expr)] //~ ERROR `cfg` is not a well-formed meta-item
38+
struct S9;
39+
}
40+
}
41+
42+
generate_s9!(concat!("nonexistent"));

‎src/test/ui/cfg-attr-syntax-validation.stderr

+60
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,60 @@
1+
error: `cfg` is not followed by parentheses
2+
--> $DIR/cfg-attr-syntax-validation.rs:11:1
3+
|
4+
LL | #[cfg] //~ ERROR `cfg` is not followed by parentheses
5+
| ^^^^^^ help: expected syntax is: `cfg(/* predicate */)`
6+
7+
error: `cfg` is not followed by parentheses
8+
--> $DIR/cfg-attr-syntax-validation.rs:14:1
9+
|
10+
LL | #[cfg = 10] //~ ERROR `cfg` is not followed by parentheses
11+
| ^^^^^^^^^^^ help: expected syntax is: `cfg(/* predicate */)`
12+
13+
error: `cfg` predicate is not specified
14+
--> $DIR/cfg-attr-syntax-validation.rs:17:1
15+
|
16+
LL | #[cfg()] //~ ERROR `cfg` predicate is not specified
17+
| ^^^^^^^^
18+
19+
error: multiple `cfg` predicates are specified
20+
--> $DIR/cfg-attr-syntax-validation.rs:20:10
21+
|
22+
LL | #[cfg(a, b)] //~ ERROR multiple `cfg` predicates are specified
23+
| ^
24+
25+
error: `cfg` predicate key cannot be a literal
26+
--> $DIR/cfg-attr-syntax-validation.rs:23:7
27+
|
28+
LL | #[cfg("str")] //~ ERROR `cfg` predicate key cannot be a literal
29+
| ^^^^^
30+
31+
error: `cfg` predicate key must be an identifier
32+
--> $DIR/cfg-attr-syntax-validation.rs:26:7
33+
|
34+
LL | #[cfg(a::b)] //~ ERROR `cfg` predicate key must be an identifier
35+
| ^^^^
36+
37+
error[E0537]: invalid predicate `a`
38+
--> $DIR/cfg-attr-syntax-validation.rs:29:7
39+
|
40+
LL | #[cfg(a())] //~ ERROR invalid predicate `a`
41+
| ^^^
42+
43+
error: literal in `cfg` predicate value must be a string
44+
--> $DIR/cfg-attr-syntax-validation.rs:32:11
45+
|
46+
LL | #[cfg(a = 10)] //~ ERROR literal in `cfg` predicate value must be a string
47+
| ^^
48+
49+
error: `cfg` is not a well-formed meta-item
50+
--> $DIR/cfg-attr-syntax-validation.rs:37:9
51+
|
52+
LL | #[cfg(feature = $expr)] //~ ERROR `cfg` is not a well-formed meta-item
53+
| ^^^^^^^^^^^^^^^^^^^^^^^ help: expected syntax is: `#[cfg(/* predicate */)]`
54+
...
55+
LL | generate_s9!(concat!("nonexistent"));
56+
| ------------------------------------- in this macro invocation
57+
58+
error: aborting due to 9 previous errors
59+
60+
For more information about this error, try `rustc --explain E0537`.

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