From 1a867dc346a0b9ea5abd8a8504f1908f42ff2dd2 Mon Sep 17 00:00:00 2001 From: "Havvy (Ryan Scheel)" Date: Mon, 10 Sep 2018 15:06:49 -0700 Subject: [PATCH] cfg_attr_multi: Basic implementation Does not implement the warning or a feature flag. --- src/libsyntax/config.rs | 59 ++++++++++++++----- src/libsyntax/parse/parser.rs | 2 +- src/test/ui/cfg-attr-trailing-comma.rs | 13 ---- src/test/ui/cfg-attr-trailing-comma.stderr | 14 ----- .../cfg-attr-crate-2.stderr | 2 +- .../cfg-attr-multi-false.rs | 19 ++++++ .../cfg-attr-multi-invalid-1.rs | 15 +++++ .../cfg-attr-multi-invalid-1.stderr | 11 ++++ .../cfg-attr-multi-invalid-2.rs | 15 +++++ .../cfg-attr-multi-invalid-2.stderr | 11 ++++ .../cfg-attr-multi-true.rs | 21 +++++++ .../cfg-attr-multi-true.stderr | 38 ++++++++++++ .../conditional-compilation/cfg-attr-parse.rs | 45 ++++++++++++++ .../cfg-attr-parse.stderr | 32 ++++++++++ 14 files changed, 252 insertions(+), 45 deletions(-) delete mode 100644 src/test/ui/cfg-attr-trailing-comma.rs delete mode 100644 src/test/ui/cfg-attr-trailing-comma.stderr create mode 100644 src/test/ui/conditional-compilation/cfg-attr-multi-false.rs create mode 100644 src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.rs create mode 100644 src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.stderr create mode 100644 src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.rs create mode 100644 src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.stderr create mode 100644 src/test/ui/conditional-compilation/cfg-attr-multi-true.rs create mode 100644 src/test/ui/conditional-compilation/cfg-attr-multi-true.stderr create mode 100644 src/test/ui/conditional-compilation/cfg-attr-parse.rs create mode 100644 src/test/ui/conditional-compilation/cfg-attr-parse.stderr diff --git a/src/libsyntax/config.rs b/src/libsyntax/config.rs index a9ce236557779..7a85f62853641 100644 --- a/src/libsyntax/config.rs +++ b/src/libsyntax/config.rs @@ -73,49 +73,76 @@ impl<'a> StripUnconfigured<'a> { if self.in_cfg(node.attrs()) { Some(node) } else { None } } + /// Parse and expand all `cfg_attr` attributes into a list of attributes + /// that are within each `cfg_attr` that has a true configuration predicate. + /// + /// Gives compiler warnigns if any `cfg_attr` does not contain any + /// attributes and is in the original source code. Gives compiler errors if + /// the syntax of any `cfg_attr` is incorrect. pub fn process_cfg_attrs(&mut self, node: T) -> T { node.map_attrs(|attrs| { - attrs.into_iter().filter_map(|attr| self.process_cfg_attr(attr)).collect() + attrs.into_iter().flat_map(|attr| self.process_cfg_attr(attr)).collect() }) } - fn process_cfg_attr(&mut self, attr: ast::Attribute) -> Option { + /// Parse and expand a single `cfg_attr` attribute into a list of attributes + /// when the configuration predicate is true, or otherwise expand into an + /// empty list of attributes. + /// + /// Gives a compiler warning when the `cfg_attr` contains no attribtes and + /// is in the original source file. Gives a compiler error if the syntax of + /// the attribute is incorrect + fn process_cfg_attr(&mut self, attr: ast::Attribute) -> Vec { if !attr.check_name("cfg_attr") { - return Some(attr); + return vec![attr]; } - let (cfg, path, tokens, span) = match attr.parse(self.sess, |parser| { + let (cfg_predicate, expanded_attrs) = match attr.parse(self.sess, |parser| { parser.expect(&token::OpenDelim(token::Paren))?; - let cfg = parser.parse_meta_item()?; + + let cfg_predicate = parser.parse_meta_item()?; parser.expect(&token::Comma)?; - let lo = parser.span.lo(); - let (path, tokens) = parser.parse_meta_item_unrestricted()?; - parser.eat(&token::Comma); // Optional trailing comma + + // Presumably, the majority of the time there will only be one attr. + let mut expanded_attrs = Vec::with_capacity(1); + + while !parser.check(&token::CloseDelim(token::Paren)) { + let lo = parser.span.lo(); + let (path, tokens) = parser.parse_meta_item_unrestricted()?; + expanded_attrs.push((path, tokens, parser.prev_span.with_lo(lo))); + parser.expect_one_of(&[token::Comma], &[token::CloseDelim(token::Paren)])?; + } + parser.expect(&token::CloseDelim(token::Paren))?; - Ok((cfg, path, tokens, parser.prev_span.with_lo(lo))) + Ok((cfg_predicate, expanded_attrs)) }) { Ok(result) => result, Err(mut e) => { e.emit(); - return None; + return Vec::new(); } }; - if attr::cfg_matches(&cfg, self.sess, self.features) { - self.process_cfg_attr(ast::Attribute { + if attr::cfg_matches(&cfg_predicate, self.sess, self.features) { + // We call `process_cfg_attr` recursively in case there's a + // `cfg_attr` inside of another `cfg_attr`. E.g. + // `#[cfg_attr(false, cfg_attr(true, some_attr))]`. + expanded_attrs.into_iter() + .flat_map(|(path, tokens, span)| self.process_cfg_attr(ast::Attribute { id: attr::mk_attr_id(), style: attr.style, path, tokens, is_sugared_doc: false, span, - }) + })) + .collect() } else { - None + Vec::new() } } - // Determine if a node with the given attributes should be included in this configuration. + /// Determine if a node with the given attributes should be included in this configuration. pub fn in_cfg(&mut self, attrs: &[ast::Attribute]) -> bool { attrs.iter().all(|attr| { if !is_cfg(attr) { @@ -165,7 +192,7 @@ impl<'a> StripUnconfigured<'a> { }) } - // Visit attributes on expression and statements (but not attributes on items in blocks). + /// Visit attributes on expression and statements (but not attributes on items in blocks). fn visit_expr_attrs(&mut self, attrs: &[ast::Attribute]) { // flag the offending attributes for attr in attrs.iter() { diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 5571a18b59625..a5ee2b0f10353 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -678,7 +678,7 @@ impl<'a> Parser<'a> { /// Expect next token to be edible or inedible token. If edible, /// then consume it; if inedible, then return without consuming /// anything. Signal a fatal error if next token is unexpected. - fn expect_one_of(&mut self, + pub fn expect_one_of(&mut self, edible: &[token::Token], inedible: &[token::Token]) -> PResult<'a, ()>{ fn tokens_to_string(tokens: &[TokenType]) -> String { diff --git a/src/test/ui/cfg-attr-trailing-comma.rs b/src/test/ui/cfg-attr-trailing-comma.rs deleted file mode 100644 index 21e00544ca00b..0000000000000 --- a/src/test/ui/cfg-attr-trailing-comma.rs +++ /dev/null @@ -1,13 +0,0 @@ -// compile-flags: --cfg TRUE - -#[cfg_attr(TRUE, inline,)] // OK -fn f() {} - -#[cfg_attr(FALSE, inline,)] // OK -fn g() {} - -#[cfg_attr(TRUE, inline,,)] //~ ERROR expected `)`, found `,` -fn h() {} - -#[cfg_attr(FALSE, inline,,)] //~ ERROR expected `)`, found `,` -fn i() {} diff --git a/src/test/ui/cfg-attr-trailing-comma.stderr b/src/test/ui/cfg-attr-trailing-comma.stderr deleted file mode 100644 index 76a470417e9ed..0000000000000 --- a/src/test/ui/cfg-attr-trailing-comma.stderr +++ /dev/null @@ -1,14 +0,0 @@ -error: expected `)`, found `,` - --> $DIR/cfg-attr-trailing-comma.rs:9:25 - | -LL | #[cfg_attr(TRUE, inline,,)] //~ ERROR expected `)`, found `,` - | ^ expected `)` - -error: expected `)`, found `,` - --> $DIR/cfg-attr-trailing-comma.rs:12:26 - | -LL | #[cfg_attr(FALSE, inline,,)] //~ ERROR expected `)`, found `,` - | ^ expected `)` - -error: aborting due to 2 previous errors - diff --git a/src/test/ui/conditional-compilation/cfg-attr-crate-2.stderr b/src/test/ui/conditional-compilation/cfg-attr-crate-2.stderr index 7b66c8f5e40f0..a730473f66315 100644 --- a/src/test/ui/conditional-compilation/cfg-attr-crate-2.stderr +++ b/src/test/ui/conditional-compilation/cfg-attr-crate-2.stderr @@ -2,7 +2,7 @@ error[E0658]: no_core is experimental (see issue #29639) --> $DIR/cfg-attr-crate-2.rs:15:21 | LL | #![cfg_attr(broken, no_core)] //~ ERROR no_core is experimental - | ^^^^^^^^ + | ^^^^^^^ | = help: add #![feature(no_core)] to the crate attributes to enable diff --git a/src/test/ui/conditional-compilation/cfg-attr-multi-false.rs b/src/test/ui/conditional-compilation/cfg-attr-multi-false.rs new file mode 100644 index 0000000000000..ff7a47e083940 --- /dev/null +++ b/src/test/ui/conditional-compilation/cfg-attr-multi-false.rs @@ -0,0 +1,19 @@ +// Test that cfg_attr doesn't emit any attributes when the +// configuation variable is false. This mirrors `cfg-attr-multi-true.rs` + +// compile-pass + +#![warn(unused_must_use)] + +#[cfg_attr(any(), deprecated, must_use)] +struct Struct {} + +impl Struct { + fn new() -> Struct { + Struct {} + } +} + +fn main() { + Struct::new(); +} diff --git a/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.rs b/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.rs new file mode 100644 index 0000000000000..a9ddbf7d80d3e --- /dev/null +++ b/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.rs @@ -0,0 +1,15 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. +// +// compile-flags: --cfg broken + +#![cfg_attr(broken, no_core, no_std)] //~ ERROR no_core is experimental + +fn main() { } diff --git a/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.stderr b/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.stderr new file mode 100644 index 0000000000000..344a05a4fecbb --- /dev/null +++ b/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-1.stderr @@ -0,0 +1,11 @@ +error[E0658]: no_core is experimental (see issue #29639) + --> $DIR/cfg-attr-multi-invalid-1.rs:13:21 + | +LL | #![cfg_attr(broken, no_core, no_std)] //~ ERROR no_core is experimental + | ^^^^^^^ + | + = help: add #![feature(no_core)] to the crate attributes to enable + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0658`. diff --git a/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.rs b/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.rs new file mode 100644 index 0000000000000..211eb08f08e28 --- /dev/null +++ b/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.rs @@ -0,0 +1,15 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. +// +// compile-flags: --cfg broken + +#![cfg_attr(broken, no_std, no_core)] //~ ERROR no_core is experimental + +fn main() { } diff --git a/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.stderr b/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.stderr new file mode 100644 index 0000000000000..54854d2e29d53 --- /dev/null +++ b/src/test/ui/conditional-compilation/cfg-attr-multi-invalid-2.stderr @@ -0,0 +1,11 @@ +error[E0658]: no_core is experimental (see issue #29639) + --> $DIR/cfg-attr-multi-invalid-2.rs:13:29 + | +LL | #![cfg_attr(broken, no_std, no_core)] //~ ERROR no_core is experimental + | ^^^^^^^ + | + = help: add #![feature(no_core)] to the crate attributes to enable + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0658`. diff --git a/src/test/ui/conditional-compilation/cfg-attr-multi-true.rs b/src/test/ui/conditional-compilation/cfg-attr-multi-true.rs new file mode 100644 index 0000000000000..4b9a8d46b9b1f --- /dev/null +++ b/src/test/ui/conditional-compilation/cfg-attr-multi-true.rs @@ -0,0 +1,21 @@ +// Test that cfg_attr with multiple attributes actually emits both attributes. +// This is done by emitting two attributes that cause new warnings, and then +// triggering those warnings. + +// compile-pass + +#![warn(unused_must_use)] + +#[cfg_attr(all(), deprecated, must_use)] +struct MustUseDeprecated {} + +impl MustUseDeprecated { //~ warning: use of deprecated item + fn new() -> MustUseDeprecated { //~ warning: use of deprecated item + MustUseDeprecated {} //~ warning: use of deprecated item + } +} + +fn main() { + MustUseDeprecated::new(); //~ warning: use of deprecated item + //| warning: unused `MustUseDeprecated` which must be used +} diff --git a/src/test/ui/conditional-compilation/cfg-attr-multi-true.stderr b/src/test/ui/conditional-compilation/cfg-attr-multi-true.stderr new file mode 100644 index 0000000000000..21634ee4f26b8 --- /dev/null +++ b/src/test/ui/conditional-compilation/cfg-attr-multi-true.stderr @@ -0,0 +1,38 @@ +warning: use of deprecated item 'MustUseDeprecated' + --> $DIR/cfg-attr-multi-true.rs:12:6 + | +LL | impl MustUseDeprecated { //~ warning: use of deprecated item + | ^^^^^^^^^^^^^^^^^ + | + = note: #[warn(deprecated)] on by default + +warning: use of deprecated item 'MustUseDeprecated' + --> $DIR/cfg-attr-multi-true.rs:19:5 + | +LL | MustUseDeprecated::new(); //~ warning: use of deprecated item + | ^^^^^^^^^^^^^^^^^^^^^^ + +warning: use of deprecated item 'MustUseDeprecated' + --> $DIR/cfg-attr-multi-true.rs:13:17 + | +LL | fn new() -> MustUseDeprecated { //~ warning: use of deprecated item + | ^^^^^^^^^^^^^^^^^ + +warning: use of deprecated item 'MustUseDeprecated' + --> $DIR/cfg-attr-multi-true.rs:14:9 + | +LL | MustUseDeprecated {} //~ warning: use of deprecated item + | ^^^^^^^^^^^^^^^^^ + +warning: unused `MustUseDeprecated` which must be used + --> $DIR/cfg-attr-multi-true.rs:19:5 + | +LL | MustUseDeprecated::new(); //~ warning: use of deprecated item + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: lint level defined here + --> $DIR/cfg-attr-multi-true.rs:7:9 + | +LL | #![warn(unused_must_use)] + | ^^^^^^^^^^^^^^^ + diff --git a/src/test/ui/conditional-compilation/cfg-attr-parse.rs b/src/test/ui/conditional-compilation/cfg-attr-parse.rs new file mode 100644 index 0000000000000..eec0e8faca877 --- /dev/null +++ b/src/test/ui/conditional-compilation/cfg-attr-parse.rs @@ -0,0 +1,45 @@ +// Parse `cfg_attr` with varying numbers of attributes and trailing commas + +#![feature(cfg_attr_multi)] + +// Completely empty `cfg_attr` input +#[cfg_attr()] //~ error: expected identifier, found `)` +struct NoConfigurationPredicate; + +// Zero attributes, zero trailing comma (comma manatory here) +#[cfg_attr(all())] //~ error: expected `,`, found `)` +struct A0C0; + +// Zero attributes, one trailing comma +#[cfg_attr(all(),)] // Ok +struct A0C1; + +// Zero attributes, two trailing commas +#[cfg_attr(all(),,)] //~ ERROR expected identifier +struct A0C2; + +// One attribute, no trailing comma +#[cfg_attr(all(), must_use)] // Ok +struct A1C0; + +// One attribute, one trailing comma +#[cfg_attr(all(), must_use,)] // Ok +struct A1C1; + +// One attribute, two trailing commas +#[cfg_attr(all(), must_use,,)] //~ ERROR expected identifier +struct A1C2; + +// Two attributes, no trailing comma +#[cfg_attr(all(), must_use, deprecated)] // Ok +struct A2C0; + +// Two attributes, one trailing comma +#[cfg_attr(all(), must_use, deprecated,)] // Ok +struct A2C1; + +// Two attributes, two trailing commas +#[cfg_attr(all(), must_use, deprecated,,)] //~ ERROR expected identifier +struct A2C2; + +fn main() {} diff --git a/src/test/ui/conditional-compilation/cfg-attr-parse.stderr b/src/test/ui/conditional-compilation/cfg-attr-parse.stderr new file mode 100644 index 0000000000000..553406b6dd83d --- /dev/null +++ b/src/test/ui/conditional-compilation/cfg-attr-parse.stderr @@ -0,0 +1,32 @@ +error: expected identifier, found `)` + --> $DIR/cfg-attr-parse.rs:6:12 + | +LL | #[cfg_attr()] //~ error: expected identifier, found `)` + | ^ expected identifier + +error: expected `,`, found `)` + --> $DIR/cfg-attr-parse.rs:10:17 + | +LL | #[cfg_attr(all())] //~ error: expected `,`, found `)` + | ^ expected `,` + +error: expected identifier, found `,` + --> $DIR/cfg-attr-parse.rs:18:18 + | +LL | #[cfg_attr(all(),,)] //~ ERROR expected identifier + | ^ expected identifier + +error: expected identifier, found `,` + --> $DIR/cfg-attr-parse.rs:30:28 + | +LL | #[cfg_attr(all(), must_use,,)] //~ ERROR expected identifier + | ^ expected identifier + +error: expected identifier, found `,` + --> $DIR/cfg-attr-parse.rs:42:40 + | +LL | #[cfg_attr(all(), must_use, deprecated,,)] //~ ERROR expected identifier + | ^ expected identifier + +error: aborting due to 5 previous errors +