Support f16 in lossy_float_literal lint

Author: samueltardieu

clippy_lints/src/float_literal.rs

@@ -99,10 +99,15 @@ impl<'tcx> LateLintPass<'tcx> for FloatLiteral {
                 LitFloatType::Unsuffixed => None,
             };
             let (is_whole, is_inf, mut float_str) = match fty {
-                FloatTy::F16 | FloatTy::F128 => {
+                FloatTy::F128 => {
                     // FIXME(f16_f128): do a check like the others when parsing is available
                     return;
                 },
+                FloatTy::F16 => {
+                    let value = sym_str.parse::<f16>().unwrap();
+
+                    (value.fract() == 0.0, value.is_infinite(), formatter.format(value))
+                },
                 FloatTy::F32 => {
                     let value = sym_str.parse::<f32>().unwrap();
 

tests/ui/lossy_float_literal.fixed

@@ -5,11 +5,16 @@
 
 fn main() {
     // Lossy whole-number float literals
-    let _: f16 = 4_097.0;
-    let _: f16 = 4_097.;
-    let _: f16 = 4_097.000;
-    let _ = 4_097f16;
-    let _: f16 = -4_097.0;
+    let _: f16 = 4_096.0;
+    //~^ lossy_float_literal
+    let _: f16 = 4_096.0;
+    //~^ lossy_float_literal
+    let _: f16 = 4_096.0;
+    //~^ lossy_float_literal
+    let _ = 4_096_f16;
+    //~^ lossy_float_literal
+    let _: f16 = -4_096.0;
+    //~^ lossy_float_literal
 
     let _: f32 = 16_777_216.0;
     //~^ lossy_float_literal

tests/ui/lossy_float_literal.rs

@@ -6,10 +6,15 @@
 fn main() {
     // Lossy whole-number float literals
     let _: f16 = 4_097.0;
+    //~^ lossy_float_literal
     let _: f16 = 4_097.;
+    //~^ lossy_float_literal
     let _: f16 = 4_097.000;
+    //~^ lossy_float_literal
     let _ = 4_097f16;
+    //~^ lossy_float_literal
     let _: f16 = -4_097.0;
+    //~^ lossy_float_literal
 
     let _: f32 = 16_777_217.0;
     //~^ lossy_float_literal

tests/ui/lossy_float_literal.stderr

@@ -1,19 +1,79 @@
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:14:18
+  --> tests/ui/lossy_float_literal.rs:8:18
    |
-LL |     let _: f32 = 16_777_217.0;
-   |                  ^^^^^^^^^^^^
+LL |     let _: f16 = 4_097.0;
+   |                  ^^^^^^^
    |
    = note: `-D clippy::lossy-float-literal` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::lossy_float_literal)]`
 help: consider changing the type or replacing it with
    |
+LL -     let _: f16 = 4_097.0;
+LL +     let _: f16 = 4_096.0;
+   |
+
+error: literal cannot be represented as the underlying type without loss of precision
+  --> tests/ui/lossy_float_literal.rs:10:18
+   |
+LL |     let _: f16 = 4_097.;
+   |                  ^^^^^^
+   |
+help: consider changing the type or replacing it with
+   |
+LL -     let _: f16 = 4_097.;
+LL +     let _: f16 = 4_096.0;
+   |
+
+error: literal cannot be represented as the underlying type without loss of precision
+  --> tests/ui/lossy_float_literal.rs:12:18
+   |
+LL |     let _: f16 = 4_097.000;
+   |                  ^^^^^^^^^
+   |
+help: consider changing the type or replacing it with
+   |
+LL -     let _: f16 = 4_097.000;
+LL +     let _: f16 = 4_096.0;
+   |
+
+error: literal cannot be represented as the underlying type without loss of precision
+  --> tests/ui/lossy_float_literal.rs:14:13
+   |
+LL |     let _ = 4_097f16;
+   |             ^^^^^^^^
+   |
+help: consider changing the type or replacing it with
+   |
+LL -     let _ = 4_097f16;
+LL +     let _ = 4_096_f16;
+   |
+
+error: literal cannot be represented as the underlying type without loss of precision
+  --> tests/ui/lossy_float_literal.rs:16:19
+   |
+LL |     let _: f16 = -4_097.0;
+   |                   ^^^^^^^
+   |
+help: consider changing the type or replacing it with
+   |
+LL -     let _: f16 = -4_097.0;
+LL +     let _: f16 = -4_096.0;
+   |
+
+error: literal cannot be represented as the underlying type without loss of precision
+  --> tests/ui/lossy_float_literal.rs:19:18
+   |
+LL |     let _: f32 = 16_777_217.0;
+   |                  ^^^^^^^^^^^^
+   |
+help: consider changing the type or replacing it with
+   |
 LL -     let _: f32 = 16_777_217.0;
 LL +     let _: f32 = 16_777_216.0;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:16:18
+  --> tests/ui/lossy_float_literal.rs:21:18
    |
 LL |     let _: f32 = 16_777_219.0;
    |                  ^^^^^^^^^^^^
@@ -25,7 +85,7 @@ LL +     let _: f32 = 16_777_220.0;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:18:18
+  --> tests/ui/lossy_float_literal.rs:23:18
    |
 LL |     let _: f32 = 16_777_219.;
    |                  ^^^^^^^^^^^
@@ -37,7 +97,7 @@ LL +     let _: f32 = 16_777_220.0;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:20:18
+  --> tests/ui/lossy_float_literal.rs:25:18
    |
 LL |     let _: f32 = 16_777_219.000;
    |                  ^^^^^^^^^^^^^^
@@ -49,7 +109,7 @@ LL +     let _: f32 = 16_777_220.0;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:22:13
+  --> tests/ui/lossy_float_literal.rs:27:13
    |
 LL |     let _ = 16_777_219f32;
    |             ^^^^^^^^^^^^^
@@ -61,7 +121,7 @@ LL +     let _ = 16_777_220_f32;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:24:19
+  --> tests/ui/lossy_float_literal.rs:29:19
    |
 LL |     let _: f32 = -16_777_219.0;
    |                   ^^^^^^^^^^^^
@@ -73,7 +133,7 @@ LL +     let _: f32 = -16_777_220.0;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:27:18
+  --> tests/ui/lossy_float_literal.rs:32:18
    |
 LL |     let _: f64 = 9_007_199_254_740_993.0;
    |                  ^^^^^^^^^^^^^^^^^^^^^^^
@@ -85,7 +145,7 @@ LL +     let _: f64 = 9_007_199_254_740_992.0;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:29:18
+  --> tests/ui/lossy_float_literal.rs:34:18
    |
 LL |     let _: f64 = 9_007_199_254_740_993.;
    |                  ^^^^^^^^^^^^^^^^^^^^^^
@@ -97,7 +157,7 @@ LL +     let _: f64 = 9_007_199_254_740_992.0;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:31:18
+  --> tests/ui/lossy_float_literal.rs:36:18
    |
 LL |     let _: f64 = 9_007_199_254_740_993.00;
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -109,7 +169,7 @@ LL +     let _: f64 = 9_007_199_254_740_992.0;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:33:13
+  --> tests/ui/lossy_float_literal.rs:38:13
    |
 LL |     let _ = 9_007_199_254_740_993f64;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -121,7 +181,7 @@ LL +     let _ = 9_007_199_254_740_992_f64;
    |
 
 error: literal cannot be represented as the underlying type without loss of precision
-  --> tests/ui/lossy_float_literal.rs:35:19
+  --> tests/ui/lossy_float_literal.rs:40:19
    |
 LL |     let _: f64 = -9_007_199_254_740_993.0;
    |                   ^^^^^^^^^^^^^^^^^^^^^^^
@@ -132,5 +192,5 @@ LL -     let _: f64 = -9_007_199_254_740_993.0;
 LL +     let _: f64 = -9_007_199_254_740_992.0;
    |
 
-error: aborting due to 11 previous errors
+error: aborting due to 16 previous errors