From acedc7b8f261e97ea544b7d43a053312e55e6ebf Mon Sep 17 00:00:00 2001
From: Yusuke Tanaka <yusuktan@maguro.dev>
Date: Thu, 11 Feb 2021 01:03:08 +0900
Subject: [PATCH] Move transmute_int_to_float to its own module

---
 clippy_lints/src/transmute/mod.rs             | 28 ++---------
 .../src/transmute/transmute_int_to_float.rs   | 48 +++++++++++++++++++
 2 files changed, 53 insertions(+), 23 deletions(-)
 create mode 100644 clippy_lints/src/transmute/transmute_int_to_float.rs

diff --git a/clippy_lints/src/transmute/mod.rs b/clippy_lints/src/transmute/mod.rs
index fa9edc9ae2c..6e1207abd52 100644
--- a/clippy_lints/src/transmute/mod.rs
+++ b/clippy_lints/src/transmute/mod.rs
@@ -1,6 +1,7 @@
 mod crosspointer_transmute;
 mod transmute_int_to_bool;
 mod transmute_int_to_char;
+mod transmute_int_to_float;
 mod transmute_ptr_to_ptr;
 mod transmute_ptr_to_ref;
 mod transmute_ref_to_ref;
@@ -385,31 +386,12 @@ impl<'tcx> LateLintPass<'tcx> for Transmute {
                 if triggered {
                     return;
                 }
+                let triggered = transmute_int_to_float::check(cx, e, from_ty, to_ty, args, const_context);
+                if triggered {
+                    return;
+                }
 
                 match (&from_ty.kind(), &to_ty.kind()) {
-                    (ty::Int(_) | ty::Uint(_), ty::Float(_)) if !const_context => span_lint_and_then(
-                        cx,
-                        TRANSMUTE_INT_TO_FLOAT,
-                        e.span,
-                        &format!("transmute from a `{}` to a `{}`", from_ty, to_ty),
-                        |diag| {
-                            let arg = sugg::Sugg::hir(cx, &args[0], "..");
-                            let arg = if let ty::Int(int_ty) = from_ty.kind() {
-                                arg.as_ty(format!(
-                                    "u{}",
-                                    int_ty.bit_width().map_or_else(|| "size".to_string(), |v| v.to_string())
-                                ))
-                            } else {
-                                arg
-                            };
-                            diag.span_suggestion(
-                                e.span,
-                                "consider using",
-                                format!("{}::from_bits({})", to_ty, arg.to_string()),
-                                Applicability::Unspecified,
-                            );
-                        },
-                    ),
                     (ty::Float(float_ty), ty::Int(_) | ty::Uint(_)) if !const_context => span_lint_and_then(
                         cx,
                         TRANSMUTE_FLOAT_TO_INT,
diff --git a/clippy_lints/src/transmute/transmute_int_to_float.rs b/clippy_lints/src/transmute/transmute_int_to_float.rs
new file mode 100644
index 00000000000..564a27df562
--- /dev/null
+++ b/clippy_lints/src/transmute/transmute_int_to_float.rs
@@ -0,0 +1,48 @@
+use super::TRANSMUTE_INT_TO_FLOAT;
+use crate::utils::{span_lint_and_then, sugg};
+use rustc_errors::Applicability;
+use rustc_hir::Expr;
+use rustc_lint::LateContext;
+use rustc_middle::ty;
+use rustc_middle::ty::Ty;
+
+/// Checks for `transmute_int_to_float` lint.
+/// Returns `true` if it's triggered, otherwise returns `false`.
+pub(super) fn check<'tcx>(
+    cx: &LateContext<'tcx>,
+    e: &'tcx Expr<'_>,
+    from_ty: Ty<'tcx>,
+    to_ty: Ty<'tcx>,
+    args: &'tcx [Expr<'_>],
+    const_context: bool,
+) -> bool {
+    match (&from_ty.kind(), &to_ty.kind()) {
+        (ty::Int(_) | ty::Uint(_), ty::Float(_)) if !const_context => {
+            span_lint_and_then(
+                cx,
+                TRANSMUTE_INT_TO_FLOAT,
+                e.span,
+                &format!("transmute from a `{}` to a `{}`", from_ty, to_ty),
+                |diag| {
+                    let arg = sugg::Sugg::hir(cx, &args[0], "..");
+                    let arg = if let ty::Int(int_ty) = from_ty.kind() {
+                        arg.as_ty(format!(
+                            "u{}",
+                            int_ty.bit_width().map_or_else(|| "size".to_string(), |v| v.to_string())
+                        ))
+                    } else {
+                        arg
+                    };
+                    diag.span_suggestion(
+                        e.span,
+                        "consider using",
+                        format!("{}::from_bits({})", to_ty, arg.to_string()),
+                        Applicability::Unspecified,
+                    );
+                },
+            );
+            true
+        },
+        _ => false,
+    }
+}