[gcc/devel/rust/master] scan-deadcode: Do not warn unused fields if they start with '_'

[Thomas Schwinge via Gcc-cvs]

https://gcc.gnu.org/g:e42c64242b8f25dcf30aee35ee059bdd8873561f

commit e42c64242b8f25dcf30aee35ee059bdd8873561f
Author: Arthur Cohen <arthur.co...@embecosm.com>
Date:   Thu Jan 30 13:08:33 2025 +0100

    scan-deadcode: Do not warn unused fields if they start with '_'
    
    gcc/rust/ChangeLog:
    
            * checks/lints/rust-lint-scan-deadcode.h: Check if the field name 
starts with an
            underscore before warning.

Diff:
---
 gcc/rust/checks/lints/rust-lint-scan-deadcode.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/gcc/rust/checks/lints/rust-lint-scan-deadcode.h 
b/gcc/rust/checks/lints/rust-lint-scan-deadcode.h
index 672c7611f539..f6a208c939de 100644
--- a/gcc/rust/checks/lints/rust-lint-scan-deadcode.h
+++ b/gcc/rust/checks/lints/rust-lint-scan-deadcode.h
@@ -93,10 +93,11 @@ public:
          {
            HirId field_hir_id = field.get_mappings ().get_hirid ();
            if (should_warn (field_hir_id)
-               && !field.get_visibility ().is_public ())
+               && !field.get_visibility ().is_public ()
+               && field.get_field_name ().as_string ().at (0) != '_')
              {
                rust_warning_at (field.get_locus (), 0,
-                                "field is never read: %<%s%>",
+                                "field is never read: %qs",
                                 field.get_field_name ().as_string ().c_str ());
              }
          }