Added a lint-fraction-readability flag to the configuration

clippy_lints/src/lib.rs

@@ -1138,7 +1138,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|| box cargo_common_metadata::CargoCommonMetadata);
     store.register_late_pass(|| box multiple_crate_versions::MultipleCrateVersions);
     store.register_late_pass(|| box wildcard_dependencies::WildcardDependencies);
-    store.register_early_pass(|| box literal_representation::LiteralDigitGrouping);
+    let literal_representation_lint_fraction_readability = conf.unreadable_literal_lint_fractions;
+    store.register_early_pass(move || box literal_representation::LiteralDigitGrouping::new(literal_representation_lint_fraction_readability));
     let literal_representation_threshold = conf.literal_representation_threshold;
     store.register_early_pass(move || box literal_representation::DecimalLiteralRepresentation::new(literal_representation_threshold));
     let enum_variant_name_threshold = conf.enum_variant_name_threshold;

clippy_lints/src/literal_representation.rs

@@ -11,7 +11,7 @@ use rustc_ast::ast::{Expr, ExprKind, Lit, LitKind};
 use rustc_errors::Applicability;
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
-use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
 
 declare_clippy_lint! {
     /// **What it does:** Warns if a long integral or floating-point constant does
@@ -32,7 +32,7 @@ declare_clippy_lint! {
     /// ```
     pub UNREADABLE_LITERAL,
     pedantic,
-    "long integer literal without underscores"
+    "long literal without underscores"
 }
 
 declare_clippy_lint! {
@@ -208,7 +208,13 @@ impl WarningType {
     }
 }
 
-declare_lint_pass!(LiteralDigitGrouping => [
+#[allow(clippy::module_name_repetitions)]
+#[derive(Copy, Clone)]
+pub struct LiteralDigitGrouping {
+    lint_fraction_readability: bool,
+}
+
+impl_lint_pass!(LiteralDigitGrouping => [
     UNREADABLE_LITERAL,
     INCONSISTENT_DIGIT_GROUPING,
     LARGE_DIGIT_GROUPS,
@@ -223,7 +229,7 @@ impl EarlyLintPass for LiteralDigitGrouping {
         }
 
         if let ExprKind::Lit(ref lit) = expr.kind {
-            Self::check_lit(cx, lit)
+            self.check_lit(cx, lit)
         }
     }
 }
@@ -232,7 +238,13 @@ impl EarlyLintPass for LiteralDigitGrouping {
 const UUID_GROUP_LENS: [usize; 5] = [8, 4, 4, 4, 12];
 
 impl LiteralDigitGrouping {
-    fn check_lit(cx: &EarlyContext<'_>, lit: &Lit) {
+    pub fn new(lint_fraction_readability: bool) -> Self {
+        Self {
+            lint_fraction_readability,
+        }
+    }
+
+    fn check_lit(self, cx: &EarlyContext<'_>, lit: &Lit) {
         if_chain! {
             if let Some(src) = snippet_opt(cx, lit.span);
             if let Some(mut num_lit) = NumericLiteral::from_lit(&src, &lit);
@@ -247,9 +259,12 @@ impl LiteralDigitGrouping {
 
                 let result = (|| {
 
-                    let integral_group_size = Self::get_group_size(num_lit.integer.split('_'), num_lit.radix)?;
+                    let integral_group_size = Self::get_group_size(num_lit.integer.split('_'), num_lit.radix, true)?;
                     if let Some(fraction) = num_lit.fraction {
-                        let fractional_group_size = Self::get_group_size(fraction.rsplit('_'), num_lit.radix)?;
+                        let fractional_group_size = Self::get_group_size(
+                            fraction.rsplit('_'),
+                            num_lit.radix,
+                            self.lint_fraction_readability)?;
 
                         let consistent = Self::parts_consistent(integral_group_size,
                                                                 fractional_group_size,
@@ -363,7 +378,11 @@ impl LiteralDigitGrouping {
 
     /// Returns the size of the digit groups (or None if ungrouped) if successful,
     /// otherwise returns a `WarningType` for linting.
-    fn get_group_size<'a>(groups: impl Iterator<Item = &'a str>, radix: Radix) -> Result<Option<usize>, WarningType> {
+    fn get_group_size<'a>(
+        groups: impl Iterator<Item = &'a str>,
+        radix: Radix,
+        lint_unreadable: bool,
+    ) -> Result<Option<usize>, WarningType> {
         let mut groups = groups.map(str::len);
 
         let first = groups.next().expect("At least one group");
@@ -380,7 +399,7 @@ impl LiteralDigitGrouping {
             } else {
                 Ok(Some(second))
             }
-        } else if first > 5 {
+        } else if first > 5 && lint_unreadable {
             Err(WarningType::UnreadableLiteral)
         } else {
             Ok(None)

clippy_lints/src/utils/conf.rs

@@ -170,6 +170,8 @@ define_Conf! {
     (warn_on_all_wildcard_imports, "warn_on_all_wildcard_imports": bool, false),
     /// Lint: DISALLOWED_METHOD. The list of blacklisted methods to lint about. NB: `bar` is not here since it has legitimate uses
     (disallowed_methods, "disallowed_methods": Vec<String>, Vec::<String>::new()),
+    /// Lint: UNREADABLE_LITERAL. Should the fraction of a decimal be linted to include separators.
+    (unreadable_literal_lint_fractions, "unreadable_literal_lint_fractions": bool, true),
 }
 
 impl Default for Conf {

tests/ui-toml/lint_decimal_readability/clippy.toml

@@ -0,0 +1 @@
+unreadable-literal-lint-fractions = false

tests/ui-toml/lint_decimal_readability/test.rs

@@ -0,0 +1,22 @@
+#[deny(clippy::unreadable_literal)]
+
+fn allow_inconsistent_digit_grouping() {
+    #![allow(clippy::inconsistent_digit_grouping)]
+    let _pass1 = 100_200_300.123456789;
+}
+
+fn main() {
+    allow_inconsistent_digit_grouping();
+
+    let _pass1 = 100_200_300.100_200_300;
+    let _pass2 = 1.123456789;
+    let _pass3 = 1.0;
+    let _pass4 = 10000.00001;
+    let _pass5 = 1.123456789e1;
+
+    // due to clippy::inconsistent-digit-grouping
+    let _fail1 = 100_200_300.123456789;
+
+    // fail due to the integer part
+    let _fail2 = 100200300.300200100;
+}

tests/ui-toml/lint_decimal_readability/test.stderr

@@ -0,0 +1,10 @@
+error: digits grouped inconsistently by underscores
+  --> $DIR/test.rs:18:18
+   |
+LL |     let _fail1 = 100_200_300.123456789;
+   |                  ^^^^^^^^^^^^^^^^^^^^^ help: consider: `100_200_300.123_456_789`
+   |
+   = note: `-D clippy::inconsistent-digit-grouping` implied by `-D warnings`
+
+error: aborting due to previous error
+

tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr

@@ -1,4 +1,4 @@
-error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown field `foobar`, expected one of `msrv`, `blacklisted-names`, `cognitive-complexity-threshold`, `cyclomatic-complexity-threshold`, `doc-valid-idents`, `too-many-arguments-threshold`, `type-complexity-threshold`, `single-char-binding-names-threshold`, `too-large-for-stack`, `enum-variant-name-threshold`, `enum-variant-size-threshold`, `verbose-bit-mask-threshold`, `literal-representation-threshold`, `trivial-copy-size-limit`, `pass-by-value-size-limit`, `too-many-lines-threshold`, `array-size-threshold`, `vec-box-size-threshold`, `max-trait-bounds`, `max-struct-bools`, `max-fn-params-bools`, `warn-on-all-wildcard-imports`, `disallowed-methods`, `third-party` at line 5 column 1
+error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown field `foobar`, expected one of `msrv`, `blacklisted-names`, `cognitive-complexity-threshold`, `cyclomatic-complexity-threshold`, `doc-valid-idents`, `too-many-arguments-threshold`, `type-complexity-threshold`, `single-char-binding-names-threshold`, `too-large-for-stack`, `enum-variant-name-threshold`, `enum-variant-size-threshold`, `verbose-bit-mask-threshold`, `literal-representation-threshold`, `trivial-copy-size-limit`, `pass-by-value-size-limit`, `too-many-lines-threshold`, `array-size-threshold`, `vec-box-size-threshold`, `max-trait-bounds`, `max-struct-bools`, `max-fn-params-bools`, `warn-on-all-wildcard-imports`, `disallowed-methods`, `unreadable-literal-lint-fractions`, `third-party` at line 5 column 1
 
 error: aborting due to previous error
 

tests/ui/unreadable_literal.fixed

@@ -10,6 +10,14 @@ macro_rules! foo {
     };
 }
 
+struct Bar(f32);
+
+macro_rules! bar {
+    () => {
+        Bar(100200300400.100200300400500)
+    };
+}
+
 fn main() {
     let _good = (
         0b1011_i64,
@@ -26,10 +34,12 @@ fn main() {
     let _good_sci = 1.1234e1;
     let _bad_sci = 1.123_456e1;
 
-    let _fail9 = 0x00ab_cdef;
-    let _fail10: u32 = 0xBAFE_BAFE;
-    let _fail11 = 0x0abc_deff;
-    let _fail12: i128 = 0x00ab_cabc_abca_bcab_cabc;
+    let _fail1 = 0x00ab_cdef;
+    let _fail2: u32 = 0xBAFE_BAFE;
+    let _fail3 = 0x0abc_deff;
+    let _fail4: i128 = 0x00ab_cabc_abca_bcab_cabc;
+    let _fail5 = 1.100_300_400;
 
     let _ = foo!();
+    let _ = bar!();
 }

tests/ui/unreadable_literal.rs

@@ -10,6 +10,14 @@ macro_rules! foo {
     };
 }
 
+struct Bar(f32);
+
+macro_rules! bar {
+    () => {
+        Bar(100200300400.100200300400500)
+    };
+}
+
 fn main() {
     let _good = (
         0b1011_i64,
@@ -26,10 +34,12 @@ fn main() {
     let _good_sci = 1.1234e1;
     let _bad_sci = 1.123456e1;
 
-    let _fail9 = 0xabcdef;
-    let _fail10: u32 = 0xBAFEBAFE;
-    let _fail11 = 0xabcdeff;
-    let _fail12: i128 = 0xabcabcabcabcabcabc;
+    let _fail1 = 0xabcdef;
+    let _fail2: u32 = 0xBAFEBAFE;
+    let _fail3 = 0xabcdeff;
+    let _fail4: i128 = 0xabcabcabcabcabcabc;
+    let _fail5 = 1.100300400;
 
     let _ = foo!();
+    let _ = bar!();
 }

tests/ui/unreadable_literal.stderr

@@ -1,66 +1,72 @@
 error: digits of hex or binary literal not grouped by four
-  --> $DIR/unreadable_literal.rs:17:9
+  --> $DIR/unreadable_literal.rs:25:9
    |
 LL |         0x1_234_567,
    |         ^^^^^^^^^^^ help: consider: `0x0123_4567`
    |
    = note: `-D clippy::unusual-byte-groupings` implied by `-D warnings`
 
 error: long literal lacking separators
-  --> $DIR/unreadable_literal.rs:25:17
+  --> $DIR/unreadable_literal.rs:33:17
    |
 LL |     let _bad = (0b110110_i64, 0xcafebabe_usize, 123456_f32, 1.234567_f32);
    |                 ^^^^^^^^^^^^ help: consider: `0b11_0110_i64`
    |
    = note: `-D clippy::unreadable-literal` implied by `-D warnings`
 
 error: long literal lacking separators
-  --> $DIR/unreadable_literal.rs:25:31
+  --> $DIR/unreadable_literal.rs:33:31
    |
 LL |     let _bad = (0b110110_i64, 0xcafebabe_usize, 123456_f32, 1.234567_f32);
    |                               ^^^^^^^^^^^^^^^^ help: consider: `0xcafe_babe_usize`
 
 error: long literal lacking separators
-  --> $DIR/unreadable_literal.rs:25:49
+  --> $DIR/unreadable_literal.rs:33:49
    |
 LL |     let _bad = (0b110110_i64, 0xcafebabe_usize, 123456_f32, 1.234567_f32);
    |                                                 ^^^^^^^^^^ help: consider: `123_456_f32`
 
 error: long literal lacking separators
-  --> $DIR/unreadable_literal.rs:25:61
+  --> $DIR/unreadable_literal.rs:33:61
    |
 LL |     let _bad = (0b110110_i64, 0xcafebabe_usize, 123456_f32, 1.234567_f32);
    |                                                             ^^^^^^^^^^^^ help: consider: `1.234_567_f32`
 
 error: long literal lacking separators
-  --> $DIR/unreadable_literal.rs:27:20
+  --> $DIR/unreadable_literal.rs:35:20
    |
 LL |     let _bad_sci = 1.123456e1;
    |                    ^^^^^^^^^^ help: consider: `1.123_456e1`
 
 error: long literal lacking separators
-  --> $DIR/unreadable_literal.rs:29:18
+  --> $DIR/unreadable_literal.rs:37:18
    |
-LL |     let _fail9 = 0xabcdef;
+LL |     let _fail1 = 0xabcdef;
    |                  ^^^^^^^^ help: consider: `0x00ab_cdef`
 
 error: long literal lacking separators
-  --> $DIR/unreadable_literal.rs:30:24
+  --> $DIR/unreadable_literal.rs:38:23
    |
-LL |     let _fail10: u32 = 0xBAFEBAFE;
-   |                        ^^^^^^^^^^ help: consider: `0xBAFE_BAFE`
+LL |     let _fail2: u32 = 0xBAFEBAFE;
+   |                       ^^^^^^^^^^ help: consider: `0xBAFE_BAFE`
 
 error: long literal lacking separators
-  --> $DIR/unreadable_literal.rs:31:19
+  --> $DIR/unreadable_literal.rs:39:18
    |
-LL |     let _fail11 = 0xabcdeff;
-   |                   ^^^^^^^^^ help: consider: `0x0abc_deff`
+LL |     let _fail3 = 0xabcdeff;
+   |                  ^^^^^^^^^ help: consider: `0x0abc_deff`
 
 error: long literal lacking separators
-  --> $DIR/unreadable_literal.rs:32:25
+  --> $DIR/unreadable_literal.rs:40:24
    |
-LL |     let _fail12: i128 = 0xabcabcabcabcabcabc;
-   |                         ^^^^^^^^^^^^^^^^^^^^ help: consider: `0x00ab_cabc_abca_bcab_cabc`
+LL |     let _fail4: i128 = 0xabcabcabcabcabcabc;
+   |                        ^^^^^^^^^^^^^^^^^^^^ help: consider: `0x00ab_cabc_abca_bcab_cabc`
 
-error: aborting due to 10 previous errors
+error: long literal lacking separators
+  --> $DIR/unreadable_literal.rs:41:18
+   |
+LL |     let _fail5 = 1.100300400;
+   |                  ^^^^^^^^^^^ help: consider: `1.100_300_400`
+
+error: aborting due to 11 previous errors