Auto merge of #118213 - Urgau:check-cfg-diagnostics-rustc-cargo, r=pe…

…trochenkov Add more suggestions to unexpected cfg names and values This pull request adds more suggestion to unexpected cfg names and values diagnostics: - it first adds a links to the [rustc unstable book](https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html) or the [Cargo reference](https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg), depending if rustc is invoked by Cargo - it secondly adds a suggestion on how to expect the cfg name or value: *excluding well known names and values* - for Cargo: it suggest using a feature or `cargo:rust-check-cfg` in build script - for rustc: it suggest using `--check-cfg` (with the correct invocation) Those diagnostics improvements are directed towards enabling users to fix the issue if the previous suggestions weren't good enough. r? `@petrochenkov`
rust-lang · Dec 13, 2023 · a90372c · a90372c
2 parents 2862500 f6617d0
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Showing 36 changed files with 468 additions and 326 deletions.
diff --git 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(

diff --git a/tests/rustdoc-ui/check-cfg/check-cfg.stderr b/tests/rustdoc-ui/check-cfg/check-cfg.stderr
@@ -4,6 4,8 @@ warning: unexpected `cfg` condition name: `uniz`
 LL | #[cfg(uniz)]
  | ^^^^ help: there is a config with a similar name: `unix`
  |
  = help: to expect this configuration use `--check-cfg=cfg(uniz)`
  = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted

diff --git a/tests/rustdoc-ui/doctest/check-cfg-test.stderr b/tests/rustdoc-ui/doctest/check-cfg-test.stderr
@@ -5,6 5,8 @@ LL | #[cfg(feature = "invalid")]
  | ^^^^^^^^^^^^^^^^^^^
  |
  = note: expected values for `feature` are: `test`
  = help: to expect this configuration use `--check-cfg=cfg(feature, values("invalid"))`
  = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted

diff --git a/tests/ui/check-cfg/allow-same-level.stderr b/tests/ui/check-cfg/allow-same-level.stderr
@@ -5,6 5,8 @@ LL | #[cfg(FALSE)]
  | ^^^^^
  |
  = help: expected names are: `debug_assertions`, `doc`, `doctest`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `unix`, `windows`
  = help: to expect this configuration use `--check-cfg=cfg(FALSE)`
  = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted

diff --git a/tests/ui/check-cfg/cargo-feature.none.stderr b/tests/ui/check-cfg/cargo-feature.none.stderr
@@ -0,0 1,31 @@
 warning: unexpected `cfg` condition name: `feature`
  --> $DIR/cargo-feature.rs:13:7
  |
 LL | #[cfg(feature = "serde")]
  | ^^^^^^^^^^^^^^^^^
  |
  = help: consider defining some features in `Cargo.toml`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition name: `tokio_unstable`
  --> $DIR/cargo-feature.rs:18:7
  |
 LL | #[cfg(tokio_unstable)]
  | ^^^^^^^^^^^^^^
  |
  = help: expected names are: `debug_assertions`, `doc`, `doctest`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `unix`, `windows`
  = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(tokio_unstable)");` to the top of a `build.rs`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition name: `CONFIG_NVME`
  --> $DIR/cargo-feature.rs:22:7
  |
 LL | #[cfg(CONFIG_NVME = "m")]
  | ^^^^^^^^^^^^^^^^^
  |
  = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(CONFIG_NVME, values(\"m\"))");` to the top of a `build.rs`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
 
 warning: 3 warnings emitted
 
diff --git a/tests/ui/check-cfg/cargo-feature.rs b/tests/ui/check-cfg/cargo-feature.rs
@@ -3,12 3,25 @@
 // list of all the expected names
 //
 // check-pass
 // revisions: some none
 // rustc-env:CARGO=/usr/bin/cargo
 // compile-flags: --check-cfg=cfg() -Z unstable-options
-// error-pattern:Cargo.toml
 // [some]compile-flags: --check-cfg=cfg(feature,values("bitcode"))
 // [some]compile-flags: --check-cfg=cfg(CONFIG_NVME,values("y"))
 // [none]error-pattern:Cargo.toml
 
 #[cfg(feature = "serde")]
-//~^ WARNING unexpected `cfg` condition name
 //[none]~^ WARNING unexpected `cfg` condition name
 //[some]~^^ WARNING unexpected `cfg` condition value
 fn ser() {}
 
 #[cfg(tokio_unstable)]
 //~^ WARNING unexpected `cfg` condition name
 fn tokio() {}
 
 #[cfg(CONFIG_NVME = "m")]
 //[none]~^ WARNING unexpected `cfg` condition name
 //[some]~^^ WARNING unexpected `cfg` condition value
 fn tokio() {}
 
 fn main() {}
diff --git a/tests/ui/check-cfg/cargo-feature.some.stderr b/tests/ui/check-cfg/cargo-feature.some.stderr
@@ -0,0 1,35 @@
 warning: unexpected `cfg` condition value: `serde`
  --> $DIR/cargo-feature.rs:13:7
  |
 LL | #[cfg(feature = "serde")]
  | ^^^^^^^^^^^^^^^^^
  |
  = note: expected values for `feature` are: `bitcode`
  = help: consider adding `serde` as a feature in `Cargo.toml`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition name: `tokio_unstable`
  --> $DIR/cargo-feature.rs:18:7
  |
 LL | #[cfg(tokio_unstable)]
  | ^^^^^^^^^^^^^^
  |
  = help: expected names are: `CONFIG_NVME`, `debug_assertions`, `doc`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `unix`, `windows`
  = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(tokio_unstable)");` to the top of a `build.rs`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `m`
  --> $DIR/cargo-feature.rs:22:7
  |
 LL | #[cfg(CONFIG_NVME = "m")]
  | ^^^^^^^^^^^^^^---
  | |
  | help: there is a expected value with a similar name: `"y"`
  |
  = note: expected values for `CONFIG_NVME` are: `y`
  = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(CONFIG_NVME, values(\"m\"))");` to the top of a `build.rs`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
 
 warning: 3 warnings emitted
 
diff --git a/tests/ui/check-cfg/cargo-feature.stderr b/tests/ui/check-cfg/cargo-feature.stderr
diff --git a/tests/ui/check-cfg/compact-names.stderr b/tests/ui/check-cfg/compact-names.stderr
@@ -5,6 5,8 @@ LL | #[cfg(target(os = "linux", architecture = "arm"))]
  | ^^^^^^^^^^^^^^^^^^^^
  |
  = help: expected names are: `debug_assertions`, `doc`, `doctest`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `unix`, `windows`
  = help: to expect this configuration use `--check-cfg=cfg(target_architecture, values("arm"))`
  = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted

diff --git a/tests/ui/check-cfg/compact-values.stderr b/tests/ui/check-cfg/compact-values.stderr
@@ -5,6 5,8 @@ LL | #[cfg(target(os = "linux", pointer_width = "X"))]
  | ^^^^^^^^^^^^^^^^^^^
  |
  = note: expected values for `target_pointer_width` are: `16`, `32`, `64`
  = help: to expect this configuration use `--check-cfg=cfg(target_pointer_width, values("X"))`
  = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted

diff --git a/tests/ui/check-cfg/concat-values.stderr b/tests/ui/check-cfg/concat-values.stderr
@@ -5,6 5,8 @@ LL | #[cfg(my_cfg)]
  | ^^^^^^
  |
  = note: expected values for `my_cfg` are: `bar`, `foo`
  = help: to expect this configuration use `--check-cfg=cfg(my_cfg)`
  = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition value: `unk`
@@ -14,6 16,8 @@ LL | #[cfg(my_cfg = "unk")]
  | ^^^^^^^^^^^^^^
  |
  = note: expected values for `my_cfg` are: `bar`, `foo`
  = help: to expect this configuration use `--check-cfg=cfg(my_cfg, values("unk"))`
  = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: 2 warnings emitted
 
diff --git a/tests/ui/check-cfg/diagnotics.cargo.stderr b/tests/ui/check-cfg/diagnotics.cargo.stderr
@@ -0,0 1,71 @@
 warning: unexpected `cfg` condition name: `featur`
  --> $DIR/diagnotics.rs:7:7
  |
 LL | #[cfg(featur)]
  | ^^^^^^ help: there is a config with a similar name: `feature`
  |
  = help: expected values for `feature` are: `foo`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
  = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition name: `featur`
  --> $DIR/diagnotics.rs:11:7
  |
 LL | #[cfg(featur = "foo")]
  | ^^^^^^^^^^^^^^
  |
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
 help: there is a config with a similar name and value
  |
 LL | #[cfg(feature = "foo")]
  | ~~~~~~~
 
 warning: unexpected `cfg` condition name: `featur`
  --> $DIR/diagnotics.rs:15:7
  |
 LL | #[cfg(featur = "fo")]
  | ^^^^^^^^^^^^^
  |
  = help: expected values for `feature` are: `foo`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
 help: there is a config with a similar name and different values
  |
 LL | #[cfg(feature = "foo")]
  | ~~~~~~~~~~~~~~~
 
 warning: unexpected `cfg` condition name: `no_value`
  --> $DIR/diagnotics.rs:22:7
  |
 LL | #[cfg(no_value)]
  | ^^^^^^^^ help: there is a config with a similar name: `no_values`
  |
  = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(no_value)");` to the top of a `build.rs`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition name: `no_value`
  --> $DIR/diagnotics.rs:26:7
  |
 LL | #[cfg(no_value = "foo")]
  | ^^^^^^^^^^^^^^^^
  |
  = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(no_value, values(\"foo\"))");` to the top of a `build.rs`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
 help: there is a config with a similar name and no value
  |
 LL | #[cfg(no_values)]
  | ~~~~~~~~~
 
 warning: unexpected `cfg` condition value: `bar`
  --> $DIR/diagnotics.rs:30:7
  |
 LL | #[cfg(no_values = "bar")]
  | ^^^^^^^^^--------
  | |
  | help: remove the value
  |
  = note: no expected value for `no_values`
  = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(no_values, values(\"bar\"))");` to the top of a `build.rs`
  = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
 
 warning: 6 warnings emitted
 
diff --git a/tests/ui/check-cfg/diagnotics.rs b/tests/ui/check-cfg/diagnotics.rs
@@ -1,4 1,7 @@
 // check-pass
 // revisions: cargo rustc
 // [rustc]unset-rustc-env:CARGO
 // [cargo]rustc-env:CARGO=/usr/bin/cargo
 // compile-flags: --check-cfg=cfg(feature,values("foo")) --check-cfg=cfg(no_values) -Z unstable-options
 
 #[cfg(featur)]