gcc/diagnostic-spec.c

   1 /* Functions to enable and disable individual warnings on an expression
   2    and statement basis.
   3    Copyright (C) 2021-2022 Free Software Foundation, Inc.
   4    Contributed by Martin Sebor <msebor@redhat.com>
   5
   6    This file is part of GCC.
   7
   8    GCC is free software; you can redistribute it and/or modify it under
   9    the terms of the GNU General Public License as published by the Free
  10    Software Foundation; either version 3, or (at your option) any later
  11    version.
  12
  13    GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16    for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with GCC; see the file COPYING3.  If not see
  20    <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "backend.h"
  26 #include "bitmap.h"
  27 #include "tree.h"
  28 #include "cgraph.h"
  29 #include "hash-map.h"
  30 #include "diagnostic-spec.h"
  31 #include "pretty-print.h"
  32 #include "options.h"
  33
  34 /* Initialize *THIS from warning option OPT.  */
  35
  36 nowarn_spec_t::nowarn_spec_t (opt_code opt)
  37 {
  38   /* Create a very simple mapping based on testing and experience.
  39      It should become more refined with time. */
  40   switch (opt)
  41     {
  42     case no_warning:
  43       m_bits = 0;
  44       break;
  45
  46     case all_warnings:
  47       m_bits = -1;
  48       break;
  49
  50       /* Flow-sensitive warnings about pointer problems issued by both
  51          front ends and the middle end.  */
  52     case OPT_Waddress:
  53     case OPT_Wnonnull:
  54       m_bits = NW_NONNULL;
  55       break;
  56
  57       /* Flow-sensitive warnings about arithmetic overflow issued by both
  58          front ends and the middle end.  */
  59     case OPT_Woverflow:
  60     case OPT_Wshift_count_negative:
  61     case OPT_Wshift_count_overflow:
  62     case OPT_Wstrict_overflow:
  63       m_bits = NW_VFLOW;
  64       break;
  65
  66       /* Lexical warnings issued by front ends.  */
  67     case OPT_Wabi:
  68     case OPT_Wlogical_op:
  69     case OPT_Wparentheses:
  70     case OPT_Wreturn_type:
  71     case OPT_Wsizeof_array_div:
  72     case OPT_Wstrict_aliasing:
  73     case OPT_Wunused:
  74     case OPT_Wunused_function:
  75     case OPT_Wunused_but_set_variable:
  76     case OPT_Wunused_variable:
  77     case OPT_Wunused_but_set_parameter:
  78       m_bits = NW_LEXICAL;
  79       break;
  80
  81       /* Access warning group.  */
  82     case OPT_Warray_bounds:
  83     case OPT_Warray_bounds_:
  84     case OPT_Wformat_overflow_:
  85     case OPT_Wformat_truncation_:
  86     case OPT_Wrestrict:
  87     case OPT_Wsizeof_pointer_memaccess:
  88     case OPT_Wstrict_aliasing_:
  89     case OPT_Wstringop_overflow_:
  90     case OPT_Wstringop_overread:
  91     case OPT_Wstringop_truncation:
  92       m_bits = NW_ACCESS;
  93       break;
  94
  95       /* Initialization warning group.  */
  96     case OPT_Winit_self:
  97     case OPT_Wuninitialized:
  98     case OPT_Wmaybe_uninitialized:
  99         m_bits = NW_UNINIT;
 100       break;
 101
 102     case OPT_Wreturn_local_addr:
 103     case OPT_Wuse_after_free_:
 104       m_bits = NW_DANGLING;
 105       break;
 106
 107     default:
 108       /* A catchall group for everything else.  */
 109       m_bits = NW_OTHER;
 110     }
 111 }
 112
 113 /* A mapping from a 'location_t' to the warning spec set for it.  */
 114
 115 GTY(()) nowarn_map_t *nowarn_map;
 116
 117 /* Return the no-warning disposition for location LOC and option OPT
 118    or for all/any otions by default.  */
 119
 120 bool
 121 warning_suppressed_at (location_t loc, opt_code opt /* = all_warnings */)
 122 {
 123   gcc_checking_assert (!RESERVED_LOCATION_P (loc));
 124
 125   if (!nowarn_map)
 126     return false;
 127
 128   if (const nowarn_spec_t* const pspec = nowarn_map->get (loc))
 129     {
 130       const nowarn_spec_t optspec (opt);
 131       return *pspec & optspec;
 132     }
 133
 134   return false;
 135 }
 136
 137  /* Change the supression of warnings for location LOC.
 138     OPT controls which warnings are affected.
 139     The wildcard OPT of -1 controls all warnings.
 140     If SUPP is true (the default), enable the suppression of the warnings.
 141     If SUPP is false, disable the suppression of the warnings.  */
 142
 143 bool
 144 suppress_warning_at (location_t loc, opt_code opt /* = all_warnings */,
 145                      bool supp /* = true */)
 146 {
 147   gcc_checking_assert (!RESERVED_LOCATION_P (loc));
 148
 149   const nowarn_spec_t optspec (supp ? opt : opt_code ());
 150
 151   if (nowarn_spec_t *pspec = nowarn_map ? nowarn_map->get (loc) : NULL)
 152     {
 153       if (supp)
 154         {
 155           *pspec |= optspec;
 156           return true;
 157         }
 158
 159       *pspec &= optspec;
 160       if (*pspec)
 161         return true;
 162
 163       nowarn_map->remove (loc);
 164       return false;
 165     }
 166
 167   if (!supp || opt == no_warning)
 168     return false;
 169
 170   if (!nowarn_map)
 171     nowarn_map = nowarn_map_t::create_ggc (32);
 172
 173   nowarn_map->put (loc, optspec);
 174   return true;
 175 }
 176
 177 /* Copy the no-warning disposition from one location to another.  */
 178
 179 void
 180 copy_warning (location_t to, location_t from)
 181 {
 182   if (!nowarn_map)
 183     return;
 184
 185   nowarn_spec_t *from_spec;
 186   if (RESERVED_LOCATION_P (from))
 187     from_spec = NULL;
 188   else
 189     from_spec = nowarn_map->get (from);
 190   if (RESERVED_LOCATION_P (to))
 191     /* We cannot set no-warning dispositions for 'to', so we have no chance but
 192        lose those potentially set for 'from'.  */
 193     ;
 194   else
 195     {
 196       if (from_spec)
 197         nowarn_map->put (to, *from_spec);
 198       else
 199         nowarn_map->remove (to);
 200     }
 201 }