diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_lint/src/context.rs | 51 |
1 files changed, 48 insertions, 3 deletions
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs index 024e542d4af..0911fa70f97 100644 --- a/compiler/rustc_lint/src/context.rs +++ b/compiler/rustc_lint/src/context.rs @@ -706,9 +706,13 @@ pub trait LintContext { }, BuiltinLintDiagnostics::UnexpectedCfgName((name, name_span), value) => { let possibilities: Vec<Symbol> = sess.parse_sess.check_config.expecteds.keys().copied().collect(); + let is_from_cargo = std::env::var_os("CARGO").is_some(); + let mut is_feature_cfg = name == sym::feature; + if is_feature_cfg && is_from_cargo { + db.help("consider defining some features in `Cargo.toml`"); // Suggest the most probable if we found one - if let Some(best_match) = find_best_match_for_name(&possibilities, name, None) { + } else if let Some(best_match) = find_best_match_for_name(&possibilities, name, None) { if let Some(ExpectedValues::Some(best_match_values)) = sess.parse_sess.check_config.expecteds.get(&best_match) { let mut possibilities = best_match_values.iter() @@ -741,8 +745,8 @@ pub trait LintContext { } else { db.span_suggestion(name_span, "there is a config with a similar name", best_match, Applicability::MaybeIncorrect); } - } else if name == sym::feature && std::env::var_os("CARGO").is_some() { - db.help("consider defining some features in `Cargo.toml`"); + + is_feature_cfg |= best_match == sym::feature; } else if !possibilities.is_empty() { let mut possibilities = possibilities.iter() .map(Symbol::as_str) @@ -756,6 +760,23 @@ pub trait LintContext { // once. db.help_once(format!("expected names are: `{possibilities}`")); } + + let inst = if let Some((value, _value_span)) = value { + let pre = if is_from_cargo { "\\" } else { "" }; + format!("cfg({name}, values({pre}\"{value}{pre}\"))") + } else { + format!("cfg({name})") + }; + + if is_from_cargo { + if !is_feature_cfg { + db.help(format!("consider using a Cargo feature instead or adding `println!(\"cargo:rustc-check-cfg={inst}\");` to the top of a `build.rs`")); + } + db.note("see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration"); + } else { + db.help(format!("to expect this configuration use `--check-cfg={inst}`")); + db.note("see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration"); + } }, BuiltinLintDiagnostics::UnexpectedCfgValue((name, name_span), value) => { let Some(ExpectedValues::Some(values)) = &sess.parse_sess.check_config.expecteds.get(&name) else { @@ -767,6 +788,7 @@ pub trait LintContext { .copied() .flatten() .collect(); + let is_from_cargo = std::env::var_os("CARGO").is_some(); // Show the full list if all possible values for a given name, but don't do it // for names as the possibilities could be very long @@ -787,6 +809,8 @@ pub trait LintContext { db.span_suggestion(value_span, "there is a expected value with a similar name", format!("\"{best_match}\""), Applicability::MaybeIncorrect); } + } else if name == sym::feature && is_from_cargo { + db.help(format!("consider defining `{name}` as feature in `Cargo.toml`")); } else if let &[first_possibility] = &possibilities[..] { db.span_suggestion(name_span.shrink_to_hi(), "specify a config value", format!(" = \"{first_possibility}\""), Applicability::MaybeIncorrect); } @@ -796,6 +820,27 @@ pub trait LintContext { db.span_suggestion(name_span.shrink_to_hi().to(value_span), "remove the value", "", Applicability::MaybeIncorrect); } } + + let inst = if let Some((value, _value_span)) = value { + let pre = if is_from_cargo { "\\" } else { "" }; + format!("cfg({name}, values({pre}\"{value}{pre}\"))") + } else { + format!("cfg({name})") + }; + + if is_from_cargo { + if name == sym::feature { + if let Some((value, _value_span)) = value { + db.help(format!("consider adding `{value}` as a feature in `Cargo.toml`")); + } + } else { + db.help(format!("consider using a Cargo feature instead or adding `println!(\"cargo:rustc-check-cfg={inst}\");` to the top of a `build.rs`")); + } + db.note("see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration"); + } else { + db.help(format!("to expect this configuration use `--check-cfg={inst}`")); + db.note("see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration"); + } }, BuiltinLintDiagnostics::DeprecatedWhereclauseLocation(new_span, suggestion) => { db.multipart_suggestion( |