Line data    Source code

       1              : // Copyright (C) 2021-2026 Free Software Foundation, Inc.
       2              : 
       3              : // This file is part of GCC.
       4              : 
       5              : // GCC is free software; you can redistribute it and/or modify it under
       6              : // the terms of the GNU General Public License as published by the Free
       7              : // Software Foundation; either version 3, or (at your option) any later
       8              : // version.
       9              : 
      10              : // GCC is distributed in the hope that it will be useful, but WITHOUT ANY
      11              : // WARRANTY; without even the implied warranty of MERCHANTABILITY or
      12              : // FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      13              : // for more details.
      14              : 
      15              : // You should have received a copy of the GNU General Public License
      16              : // along with GCC; see the file COPYING3.  If not see
      17              : // <http://www.gnu.org/licenses/>.
      18              : 
      19              : #include "rust-lint-unused-var.h"
      20              : #include "rust-gcc.h"
      21              : 
      22              : namespace Rust {
      23              : namespace Analysis {
      24              : 
      25              : static void
      26        52525 : check_decl (tree *t)
      27              : {
      28        52525 :   rust_assert (TREE_CODE (*t) == VAR_DECL || TREE_CODE (*t) == PARM_DECL
      29              :                || TREE_CODE (*t) == CONST_DECL);
      30              : 
      31        52525 :   tree var_name = DECL_NAME (*t);
      32        52525 :   const char *var_name_ptr = IDENTIFIER_POINTER (var_name);
      33        52525 :   bool starts_with_under_score = strncmp (var_name_ptr, "_", 1) == 0;
      34        52525 :   bool is_self = strcmp (var_name_ptr, "self") == 0;
      35              : 
      36        52525 :   bool is_constant = TREE_CODE (*t) == CONST_DECL;
      37              :   // if (!is_constant)
      38              :   //   {
      39              :   //     debug_tree (*t);
      40              :   //     rust_debug ("found var-decl: used %s artifical %s underscore %s name
      41              :   //     %s",
      42              :   //              TREE_USED (*t) ? "true" : "false",
      43              :   //              DECL_ARTIFICIAL (*t) ? "true" : "false",
      44              :   //              starts_with_under_score ? "true" : "false", var_name_ptr);
      45              :   //   }
      46              : 
      47         2816 :   if (!TREE_USED (*t) && !DECL_ARTIFICIAL (*t) && !starts_with_under_score
      48        55302 :       && !is_self)
      49              :     {
      50         1959 :       warning_at (DECL_SOURCE_LOCATION (*t),
      51         3891 :                   is_constant ? OPT_Wunused_const_variable_
      52              :                               : OPT_Wunused_variable,
      53              :                   "unused name %qE", *t);
      54              :     }
      55        52525 : }
      56              : 
      57              : static tree
      58       378003 : unused_var_walk_fn (tree *t, int *, void *)
      59              : {
      60       378003 :   switch (TREE_CODE (*t))
      61              :     {
      62        37189 :     case VAR_DECL:
      63        37189 :     case CONST_DECL:
      64        37189 :       check_decl (t);
      65        37189 :       break;
      66              : 
      67              :     default:
      68              :       break;
      69              :     }
      70       378003 :   return NULL_TREE;
      71              : }
      72              : 
      73              : void
      74         4019 : UnusedVariables::Lint (Compile::Context &ctx)
      75              : {
      76        18778 :   for (auto &fndecl : ctx.get_func_decls ())
      77              :     {
      78        29555 :       for (tree p = DECL_ARGUMENTS (fndecl); p != NULL_TREE; p = DECL_CHAIN (p))
      79              :         {
      80        14796 :           check_decl (&p);
      81              :         }
      82              : 
      83        14759 :       walk_tree_without_duplicates (&DECL_SAVED_TREE (fndecl),
      84              :                                     &unused_var_walk_fn, &ctx);
      85              :     }
      86              : 
      87         4065 :   for (auto &var : ctx.get_var_decls ())
      88              :     {
      89           46 :       tree decl = var->get_decl ();
      90           46 :       check_decl (&decl);
      91              :     }
      92              : 
      93         4513 :   for (auto &const_decl : ctx.get_const_decls ())
      94              :     {
      95          494 :       check_decl (&const_decl);
      96              :     }
      97         4019 : }
      98              : 
      99              : } // namespace Analysis
     100              : } // namespace Rust