fix: uninlined_format_args shouldn't inline panic! before 2021ed

clippy_lints/src/format_args.rs

@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::macros::FormatParamKind::{Implicit, Named, Numbered, Starred};
-use clippy_utils::macros::{is_format_macro, FormatArgsExpn, FormatParam, FormatParamUsage};
+use clippy_utils::macros::{is_format_macro, is_panic, FormatArgsExpn, FormatParam, FormatParamUsage};
 use clippy_utils::source::snippet_opt;
 use clippy_utils::ty::implements_trait;
 use clippy_utils::{is_diag_trait_item, meets_msrv, msrvs};
@@ -13,6 +13,8 @@ use rustc_middle::ty::adjustment::{Adjust, Adjustment};
 use rustc_middle::ty::Ty;
 use rustc_semver::RustcVersion;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::DefId;
+use rustc_span::edition::Edition::Edition2021;
 use rustc_span::{sym, ExpnData, ExpnKind, Span, Symbol};
 
 declare_clippy_lint! {
@@ -149,7 +151,7 @@ impl<'tcx> LateLintPass<'tcx> for FormatArgs {
                     check_to_string_in_format_args(cx, name, arg.param.value);
                 }
                 if meets_msrv(self.msrv, msrvs::FORMAT_ARGS_CAPTURE) {
-                    check_uninlined_args(cx, &format_args, outermost_expn_data.call_site);
+                    check_uninlined_args(cx, &format_args, outermost_expn_data.call_site, macro_def_id);
                 }
             }
         }
@@ -158,10 +160,14 @@ impl<'tcx> LateLintPass<'tcx> for FormatArgs {
     extract_msrv_attr!(LateContext);
 }
 
-fn check_uninlined_args(cx: &LateContext<'_>, args: &FormatArgsExpn<'_>, call_site: Span) {
+fn check_uninlined_args(cx: &LateContext<'_>, args: &FormatArgsExpn<'_>, call_site: Span, def_id: DefId) {
     if args.format_string.span.from_expansion() {
         return;
     }
+    if call_site.edition() < Edition2021 && is_panic(cx, def_id) {
+        // panic! before 2021 edition considers a single string argument as non-format
+        return;
+    }
 
     let mut fixes = Vec::new();
     // If any of the arguments are referenced by an index number,

tests/ui/uninlined_format_args.fixed

@@ -150,6 +150,19 @@ fn tester(fn_arg: i32) {
 
     println!(with_span!("{0} {1}" "{1} {0}"), local_i32, local_f64);
     println!("{}", with_span!(span val));
+
+    if local_i32 > 0 {
+        panic!("p1 {local_i32}");
+    }
+    if local_i32 > 0 {
+        panic!("p2 {local_i32}");
+    }
+    if local_i32 > 0 {
+        panic!("p3 {local_i32}");
+    }
+    if local_i32 > 0 {
+        panic!("p4 {local_i32}");
+    }
 }
 
 fn main() {

tests/ui/uninlined_format_args.rs

@@ -150,6 +150,19 @@ fn tester(fn_arg: i32) {
 
     println!(with_span!("{0} {1}" "{1} {0}"), local_i32, local_f64);
     println!("{}", with_span!(span val));
+
+    if local_i32 > 0 {
+        panic!("p1 {}", local_i32);
+    }
+    if local_i32 > 0 {
+        panic!("p2 {0}", local_i32);
+    }
+    if local_i32 > 0 {
+        panic!("p3 {local_i32}", local_i32 = local_i32);
+    }
+    if local_i32 > 0 {
+        panic!("p4 {local_i32}");
+    }
 }
 
 fn main() {

tests/ui/uninlined_format_args.stderr

@@ -828,7 +828,43 @@ LL +     println!("{val}");
    |
 
 error: variables can be used directly in the `format!` string
-  --> $DIR/uninlined_format_args.rs:168:5
+  --> $DIR/uninlined_format_args.rs:155:9
+   |
+LL |         panic!("p1 {}", local_i32);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: change this to
+   |
+LL -         panic!("p1 {}", local_i32);
+LL +         panic!("p1 {local_i32}");
+   |
+
+error: variables can be used directly in the `format!` string
+  --> $DIR/uninlined_format_args.rs:158:9
+   |
+LL |         panic!("p2 {0}", local_i32);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: change this to
+   |
+LL -         panic!("p2 {0}", local_i32);
+LL +         panic!("p2 {local_i32}");
+   |
+
+error: variables can be used directly in the `format!` string
+  --> $DIR/uninlined_format_args.rs:161:9
+   |
+LL |         panic!("p3 {local_i32}", local_i32 = local_i32);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: change this to
+   |
+LL -         panic!("p3 {local_i32}", local_i32 = local_i32);
+LL +         panic!("p3 {local_i32}");
+   |
+
+error: variables can be used directly in the `format!` string
+  --> $DIR/uninlined_format_args.rs:181:5
    |
 LL |     println!("expand='{}'", local_i32);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -839,5 +875,5 @@ LL -     println!("expand='{}'", local_i32);
 LL +     println!("expand='{local_i32}'");
    |
 
-error: aborting due to 70 previous errors
+error: aborting due to 73 previous errors
 

tests/ui/uninlined_format_args_2018.fixed

@@ -0,0 +1,27 @@
+// run-rustfix
+// edition:2018
+
+#![warn(clippy::uninlined_format_args)]
+
+fn main() {
+    let var = 1;
+
+    println!("val='{var}'");
+
+    if var > 0 {
+        panic!("p1 {}", var);
+    }
+    if var > 0 {
+        panic!("p2 {0}", var);
+    }
+    if var > 0 {
+        panic!("p3 {var}", var = var);
+    }
+
+    #[allow(non_fmt_panics)]
+    {
+        if var > 0 {
+            panic!("p4 {var}");
+        }
+    }
+}

tests/ui/uninlined_format_args_2018.rs

@@ -0,0 +1,27 @@
+// run-rustfix
+// edition:2018
+
+#![warn(clippy::uninlined_format_args)]
+
+fn main() {
+    let var = 1;
+
+    println!("val='{}'", var);
+
+    if var > 0 {
+        panic!("p1 {}", var);
+    }
+    if var > 0 {
+        panic!("p2 {0}", var);
+    }
+    if var > 0 {
+        panic!("p3 {var}", var = var);
+    }
+
+    #[allow(non_fmt_panics)]
+    {
+        if var > 0 {
+            panic!("p4 {var}");
+        }
+    }
+}

tests/ui/uninlined_format_args_2018.stderr

@@ -0,0 +1,15 @@
+error: variables can be used directly in the `format!` string
+  --> $DIR/uninlined_format_args_2018.rs:9:5
+   |
+LL |     println!("val='{}'", var);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `-D clippy::uninlined-format-args` implied by `-D warnings`
+help: change this to
+   |
+LL -     println!("val='{}'", var);
+LL +     println!("val='{var}'");
+   |
+
+error: aborting due to previous error
+

tests/ui/uninlined_format_args_2021.fixed

@@ -0,0 +1,23 @@
+// run-rustfix
+// edition:2021
+
+#![warn(clippy::uninlined_format_args)]
+
+fn main() {
+    let var = 1;
+
+    println!("val='{var}'");
+
+    if var > 0 {
+        panic!("p1 {var}");
+    }
+    if var > 0 {
+        panic!("p2 {var}");
+    }
+    if var > 0 {
+        panic!("p3 {var}");
+    }
+    if var > 0 {
+        panic!("p4 {var}");
+    }
+}

tests/ui/uninlined_format_args_2021.rs

@@ -0,0 +1,23 @@
+// run-rustfix
+// edition:2021
+
+#![warn(clippy::uninlined_format_args)]
+
+fn main() {
+    let var = 1;
+
+    println!("val='{}'", var);
+
+    if var > 0 {
+        panic!("p1 {}", var);
+    }
+    if var > 0 {
+        panic!("p2 {0}", var);
+    }
+    if var > 0 {
+        panic!("p3 {var}", var = var);
+    }
+    if var > 0 {
+        panic!("p4 {var}");
+    }
+}

tests/ui/uninlined_format_args_2021.stderr

@@ -0,0 +1,51 @@
+error: variables can be used directly in the `format!` string
+  --> $DIR/uninlined_format_args_2021.rs:9:5
+   |
+LL |     println!("val='{}'", var);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `-D clippy::uninlined-format-args` implied by `-D warnings`
+help: change this to
+   |
+LL -     println!("val='{}'", var);
+LL +     println!("val='{var}'");
+   |
+
+error: variables can be used directly in the `format!` string
+  --> $DIR/uninlined_format_args_2021.rs:12:9
+   |
+LL |         panic!("p1 {}", var);
+   |         ^^^^^^^^^^^^^^^^^^^^
+   |
+help: change this to
+   |
+LL -         panic!("p1 {}", var);
+LL +         panic!("p1 {var}");
+   |
+
+error: variables can be used directly in the `format!` string
+  --> $DIR/uninlined_format_args_2021.rs:15:9
+   |
+LL |         panic!("p2 {0}", var);
+   |         ^^^^^^^^^^^^^^^^^^^^^
+   |
+help: change this to
+   |
+LL -         panic!("p2 {0}", var);
+LL +         panic!("p2 {var}");
+   |
+
+error: variables can be used directly in the `format!` string
+  --> $DIR/uninlined_format_args_2021.rs:18:9
+   |
+LL |         panic!("p3 {var}", var = var);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: change this to
+   |
+LL -         panic!("p3 {var}", var = var);
+LL +         panic!("p3 {var}");
+   |
+
+error: aborting due to 4 previous errors
+