From bf55aee7b142ad14d102de3260e314a84bf8c35c Mon Sep 17 00:00:00 2001
From: bool <booleancoercion@gmail.com>
Date: Fri, 19 Feb 2021 19:36:28 +0200
Subject: [PATCH] Updated from_str_radix_10 sugg to be slightly smarter and ran
 bless

---
 clippy_lints/src/from_str_radix_10.rs | 26 ++++++++++++++++++++++----
 tests/ui/from_str_radix_10.rs         |  3 +++
 tests/ui/from_str_radix_10.stderr     | 10 ++++++++--
 3 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/clippy_lints/src/from_str_radix_10.rs b/clippy_lints/src/from_str_radix_10.rs
index 993b85ed9..d0a170acb 100644
--- a/clippy_lints/src/from_str_radix_10.rs
+++ b/clippy_lints/src/from_str_radix_10.rs
@@ -1,9 +1,12 @@
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::*;
+use rustc_hir::{def, Expr, ExprKind, PrimTy, QPath, TyKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::Ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::sym;
 
+use crate::utils::is_type_diagnostic_item;
 use crate::utils::span_lint_and_sugg;
 use crate::utils::sugg::Sugg;
 
@@ -40,8 +43,7 @@ impl LateLintPass<'tcx> for FromStrRadix10 {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, exp: &Expr<'tcx>) {
         if_chain! {
             if let ExprKind::Call(maybe_path, arguments) = &exp.kind;
-            if let ExprKind::Path(qpath) = &maybe_path.kind;
-            if let QPath::TypeRelative(ty, pathseg) = &qpath;
+            if let ExprKind::Path(QPath::TypeRelative(ty, pathseg)) = &maybe_path.kind;
 
             // check if the first part of the path is some integer primitive
             if let TyKind::Path(ty_qpath) = &ty.kind;
@@ -59,9 +61,20 @@ impl LateLintPass<'tcx> for FromStrRadix10 {
             if let rustc_ast::ast::LitKind::Int(10, _) = lit.node;
 
             then {
+                let expr = if let ExprKind::AddrOf(_, _, expr) = &arguments[0].kind {
+                    let ty = cx.typeck_results().expr_ty(expr);
+                    if is_ty_stringish(cx, ty) {
+                        expr
+                    } else {
+                        &arguments[0]
+                    }
+                } else {
+                    &arguments[0]
+                };
+
                 let sugg = Sugg::hir_with_applicability(
                     cx,
-                    &arguments[0],
+                    expr,
                     "<string>",
                     &mut Applicability::MachineApplicable
                 ).maybe_par();
@@ -79,3 +92,8 @@ impl LateLintPass<'tcx> for FromStrRadix10 {
         }
     }
 }
+
+/// Checks if a Ty is `String` or `&str`
+fn is_ty_stringish(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
+    is_type_diagnostic_item(cx, ty, sym::string_type) || is_type_diagnostic_item(cx, ty, sym::str)
+}
diff --git a/tests/ui/from_str_radix_10.rs b/tests/ui/from_str_radix_10.rs
index 0a9731286..2f2ea0484 100644
--- a/tests/ui/from_str_radix_10.rs
+++ b/tests/ui/from_str_radix_10.rs
@@ -35,6 +35,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let string = "300";
     i32::from_str_radix(string, 10)?;
 
+    let stringier = "400".to_string();
+    i32::from_str_radix(&stringier, 10)?;
+
     // none of these should trigger the lint
     u16::from_str_radix("20", 3)?;
     i32::from_str_radix("45", 12)?;
diff --git a/tests/ui/from_str_radix_10.stderr b/tests/ui/from_str_radix_10.stderr
index d66690019..471bf52a9 100644
--- a/tests/ui/from_str_radix_10.stderr
+++ b/tests/ui/from_str_radix_10.stderr
@@ -28,7 +28,7 @@ error: this call to `from_str_radix` can be replaced with a call to `str::parse`
   --> $DIR/from_str_radix_10.rs:32:5
    |
 LL |     u16::from_str_radix(&("10".to_owned() + "5"), 10)?;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `(&("10".to_owned() + "5")).parse::<u16>()`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `(("10".to_owned() + "5")).parse::<u16>()`
 
 error: this call to `from_str_radix` can be replaced with a call to `str::parse`
   --> $DIR/from_str_radix_10.rs:33:5
@@ -42,5 +42,11 @@ error: this call to `from_str_radix` can be replaced with a call to `str::parse`
 LL |     i32::from_str_radix(string, 10)?;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `string.parse::<i32>()`
 
-error: aborting due to 7 previous errors
+error: this call to `from_str_radix` can be replaced with a call to `str::parse`
+  --> $DIR/from_str_radix_10.rs:39:5
+   |
+LL |     i32::from_str_radix(&stringier, 10)?;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `stringier.parse::<i32>()`
+
+error: aborting due to 8 previous errors