gcc/config/riscv/riscv-target-attr.cc

   1 /* Subroutines used for parsing target attribute for RISC-V.
   2    Copyright (C) 2023-2024 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #define IN_TARGET_CODE 1
  21
  22 #define INCLUDE_MEMORY
  23 #define INCLUDE_STRING
  24 #include "config.h"
  25 #include "system.h"
  26 #include "coretypes.h"
  27 #include "target.h"
  28 #include "tree.h"
  29 #include "tm_p.h"
  30 #include "diagnostic.h"
  31 #include "opts.h"
  32 #include "riscv-subset.h"
  33
  34 namespace {
  35 class riscv_target_attr_parser
  36 {
  37 public:
  38   riscv_target_attr_parser (location_t loc)
  39     : m_found_arch_p (false)
  40     , m_found_tune_p (false)
  41     , m_found_cpu_p (false)
  42     , m_subset_list (nullptr)
  43     , m_loc (loc)
  44     , m_cpu_info (nullptr)
  45     , m_tune (nullptr)
  46   {
  47   }
  48
  49   bool handle_arch (const char *);
  50   bool handle_cpu (const char *);
  51   bool handle_tune (const char *);
  52
  53   void update_settings (struct gcc_options *opts) const;
  54 private:
  55   const char *m_raw_attr_str;
  56   bool parse_arch (const char *);
  57
  58   bool m_found_arch_p;
  59   bool m_found_tune_p;
  60   bool m_found_cpu_p;
  61   riscv_subset_list *m_subset_list;
  62   location_t m_loc;
  63   const  riscv_cpu_info *m_cpu_info;
  64   const char *m_tune;
  65 };
  66 }
  67
  68 /* All the information needed to handle a target attribute.
  69    NAME is the name of the attribute.
  70    HANDLER is the function that takes the attribute string as an argument.  */
  71
  72 struct riscv_attribute_info
  73 {
  74   const char *name;
  75   bool (riscv_target_attr_parser::*handler) (const char *);
  76 };
  77
  78 /* The target attributes that we support.  */
  79
  80 static const struct riscv_attribute_info riscv_attributes[]
  81   = {{"arch", &riscv_target_attr_parser::handle_arch},
  82      {"cpu", &riscv_target_attr_parser::handle_cpu},
  83      {"tune", &riscv_target_attr_parser::handle_tune}};
  84
  85 bool
  86 riscv_target_attr_parser::parse_arch (const char *str)
  87 {
  88   if (m_subset_list)
  89     delete m_subset_list;
  90   /* Check if it's setting full arch string.  */
  91   if (strncmp ("rv", str, strlen ("rv")) == 0)
  92     {
  93       m_subset_list = riscv_subset_list::parse (str, m_loc);
  94
  95       if (m_subset_list == nullptr)
  96         goto fail;
  97
  98       return true;
  99     }
 100   else
 101     {
 102       /* Parsing the extension list like "+<ext>[,+<ext>]*".  */
 103       size_t len = strlen (str);
 104       std::unique_ptr<char[]> buf (new char[len+1]);
 105       char *str_to_check = buf.get ();
 106       strcpy (str_to_check, str);
 107       const char *token = strtok_r (str_to_check, ",", &str_to_check);
 108       const char *local_arch_str = global_options.x_riscv_arch_string;
 109       m_subset_list = local_arch_str
 110                       ? riscv_subset_list::parse (local_arch_str, m_loc)
 111                       : riscv_cmdline_subset_list ()->clone ();
 112       m_subset_list->set_loc (m_loc);
 113       m_subset_list->set_allow_adding_dup (true);
 114
 115       while (token)
 116         {
 117           if (token[0] != '+')
 118             {
 119               error_at (
 120                 m_loc,
 121                 "unexpected arch for %<target()%> attribute: must start "
 122                 "with + or rv");
 123               goto fail;
 124             }
 125
 126           const char *result = m_subset_list->parse_single_ext (token + 1);
 127           /* Check parse_single_ext has consume all string.  */
 128           if (*result != '\0')
 129             {
 130               error_at (
 131                 m_loc,
 132                 "unexpected arch for %<target()%> attribute: bad "
 133                 "string found %<%s%>", token);
 134               goto fail;
 135             }
 136
 137           token = strtok_r (NULL, ",", &str_to_check);
 138         }
 139
 140       m_subset_list->set_allow_adding_dup (false);
 141       m_subset_list->finalize ();
 142       return true;
 143     }
 144 fail:
 145   if (m_subset_list != nullptr)
 146     {
 147       delete m_subset_list;
 148       m_subset_list = nullptr;
 149     }
 150   return false;
 151 }
 152
 153 /* Handle the ARCH_STR argument to the arch= target attribute.  */
 154
 155 bool
 156 riscv_target_attr_parser::handle_arch (const char *str)
 157 {
 158   if (m_found_arch_p)
 159     error_at (m_loc, "%<target()%> attribute: arch appears more than once");
 160   m_found_arch_p = true;
 161   return parse_arch (str);
 162 }
 163
 164 /* Handle the CPU_STR argument to the cpu= target attribute.  */
 165
 166 bool
 167 riscv_target_attr_parser::handle_cpu (const char *str)
 168 {
 169   if (m_found_cpu_p)
 170     error_at (m_loc, "%<target()%> attribute: cpu appears more than once");
 171
 172   m_found_cpu_p = true;
 173   const riscv_cpu_info *cpu_info = riscv_find_cpu (str);
 174
 175   if (!cpu_info)
 176     {
 177       error_at (m_loc, "%<target()%> attribute: unknown CPU %qs", str);
 178       return false;
 179     }
 180
 181   if (m_subset_list == nullptr)
 182     {
 183       const char *arch_str = cpu_info->arch;
 184       m_subset_list = riscv_subset_list::parse (arch_str, m_loc);
 185       gcc_assert (m_subset_list);
 186     }
 187
 188   m_cpu_info = cpu_info;
 189   return true;
 190 }
 191
 192 /* Handle the TUNE_STR argument to the tune= target attribute.  */
 193
 194 bool
 195 riscv_target_attr_parser::handle_tune (const char *str)
 196 {
 197   if (m_found_tune_p)
 198     error_at (m_loc, "%<target()%> attribute: tune appears more than once");
 199   m_found_tune_p = true;
 200   const struct riscv_tune_info *tune = riscv_parse_tune (str, true);
 201
 202   if (tune == nullptr)
 203     {
 204       error_at (m_loc, "%<target()%> attribute: unknown TUNE %qs", str);
 205       return false;
 206     }
 207
 208   m_tune = tune->name;
 209
 210   return true;
 211 }
 212
 213 void
 214 riscv_target_attr_parser::update_settings (struct gcc_options *opts) const
 215 {
 216   if (m_subset_list)
 217     {
 218       std::string local_arch = m_subset_list->to_string (true);
 219       const char* local_arch_str = local_arch.c_str ();
 220       struct cl_target_option *default_opts
 221         = TREE_TARGET_OPTION (target_option_default_node);
 222       if (opts->x_riscv_arch_string != default_opts->x_riscv_arch_string)
 223         free (CONST_CAST (void *, (const void *) opts->x_riscv_arch_string));
 224       opts->x_riscv_arch_string = xstrdup (local_arch_str);
 225
 226       riscv_set_arch_by_subset_list (m_subset_list, opts);
 227     }
 228
 229   if (m_cpu_info)
 230     opts->x_riscv_cpu_string = m_cpu_info->name;
 231
 232   if (m_tune)
 233     opts->x_riscv_tune_string = m_tune;
 234   else
 235     {
 236       if (m_cpu_info)
 237         opts->x_riscv_tune_string = m_cpu_info->tune;
 238     }
 239 }
 240
 241 /* Parse ARG_STR which contains the definition of one target attribute.
 242    Show appropriate errors if any or return true if the attribute is valid.  */
 243
 244 static bool
 245 riscv_process_one_target_attr (char *arg_str,
 246                                location_t loc,
 247                                riscv_target_attr_parser &attr_parser)
 248 {
 249   size_t len = strlen (arg_str);
 250
 251   if (len == 0)
 252     {
 253       error_at (loc, "malformed %<target()%> attribute");
 254       return false;
 255     }
 256
 257   std::unique_ptr<char[]> buf (new char[len+1]);
 258   char *str_to_check = buf.get();
 259   strcpy (str_to_check, arg_str);
 260
 261   char *arg = strchr (str_to_check, '=');
 262
 263   if (!arg)
 264     {
 265       error_at (
 266         loc,
 267         "attribute %<target(\"%s\")%> does not accept an argument",
 268         str_to_check);
 269       return false;
 270     }
 271
 272   arg[0] = '\0';
 273   ++arg;
 274   for (const auto &attr : riscv_attributes)
 275     {
 276       /* If the names don't match up, or the user has given an argument
 277          to an attribute that doesn't accept one, or didn't give an argument
 278          to an attribute that expects one, fail to match.  */
 279       if (strncmp (str_to_check, attr.name, strlen (attr.name)) != 0)
 280         continue;
 281
 282       return (&attr_parser->*attr.handler) (arg);
 283     }
 284
 285   error_at (loc, "Got unknown attribute %<target(\"%s\")%>", str_to_check);
 286   return false;
 287 }
 288
 289 /* Count how many times the character C appears in
 290    NULL-terminated string STR.  */
 291
 292 static unsigned int
 293 num_occurrences_in_str (char c, char *str)
 294 {
 295   unsigned int res = 0;
 296   while (*str != '\0')
 297     {
 298       if (*str == c)
 299         res++;
 300
 301       str++;
 302     }
 303
 304   return res;
 305 }
 306
 307 /* Parse the tree in ARGS that contains the target attribute information
 308    and update the global target options space.  */
 309
 310 static bool
 311 riscv_process_target_attr (tree args, location_t loc)
 312 {
 313   if (TREE_CODE (args) == TREE_LIST)
 314     {
 315       do
 316         {
 317           tree head = TREE_VALUE (args);
 318           if (head)
 319             {
 320               if (!riscv_process_target_attr (head, loc))
 321                 return false;
 322             }
 323           args = TREE_CHAIN (args);
 324       } while (args);
 325
 326       return true;
 327     }
 328
 329   if (TREE_CODE (args) != STRING_CST)
 330     {
 331       error_at (loc, "attribute %<target%> argument not a string");
 332       return false;
 333     }
 334
 335   size_t len = strlen (TREE_STRING_POINTER (args));
 336
 337   /* No need to emit warning or error on empty string here, generic code already
 338      handle this case.  */
 339   if (len == 0)
 340     {
 341       return false;
 342     }
 343
 344   std::unique_ptr<char[]> buf (new char[len+1]);
 345   char *str_to_check = buf.get ();
 346   strcpy (str_to_check, TREE_STRING_POINTER (args));
 347
 348   /* Used to catch empty spaces between semi-colons i.e.
 349      attribute ((target ("attr1;;attr2"))).  */
 350   unsigned int num_semicolons = num_occurrences_in_str (';', str_to_check);
 351
 352   /* Handle multiple target attributes separated by ';'.  */
 353   char *token = strtok_r (str_to_check, ";", &str_to_check);
 354
 355   riscv_target_attr_parser attr_parser (loc);
 356   unsigned int num_attrs = 0;
 357   while (token)
 358     {
 359       num_attrs++;
 360       if (!riscv_process_one_target_attr (token, loc, attr_parser))
 361         return false;
 362
 363       token = strtok_r (NULL, ";", &str_to_check);
 364     }
 365
 366   if (num_attrs != num_semicolons + 1)
 367     {
 368       error_at (loc, "malformed %<target(\"%s\")%> attribute",
 369                 TREE_STRING_POINTER (args));
 370       return false;
 371     }
 372
 373   /* Apply settings from target attribute.  */
 374   attr_parser.update_settings (&global_options);
 375
 376   return true;
 377 }
 378
 379 /* Implement TARGET_OPTION_VALID_ATTRIBUTE_P.
 380    This is used to process attribute ((target ("..."))).
 381    Note, that riscv_set_current_function() has not been called before,
 382    so we need must not mess with the current global_options, which
 383    likely belong to another function.  */
 384
 385 bool
 386 riscv_option_valid_attribute_p (tree fndecl, tree, tree args, int)
 387 {
 388   struct cl_target_option cur_target;
 389   bool ret;
 390   tree new_target;
 391   tree existing_target = DECL_FUNCTION_SPECIFIC_TARGET (fndecl);
 392   location_t loc = DECL_SOURCE_LOCATION (fndecl);
 393
 394   /* Save the current target options to restore at the end.  */
 395   cl_target_option_save (&cur_target, &global_options, &global_options_set);
 396
 397   /* If fndecl already has some target attributes applied to it, unpack
 398      them so that we add this attribute on top of them, rather than
 399      overwriting them.  */
 400   if (existing_target)
 401     {
 402       struct cl_target_option *existing_options
 403         = TREE_TARGET_OPTION (existing_target);
 404
 405       if (existing_options)
 406         cl_target_option_restore (&global_options, &global_options_set,
 407                                   existing_options);
 408     }
 409   else
 410     cl_target_option_restore (&global_options, &global_options_set,
 411                               TREE_TARGET_OPTION (target_option_default_node));
 412
 413   /* Now we can parse the attributes and set &global_options accordingly.  */
 414   ret = riscv_process_target_attr (args, loc);
 415   if (ret)
 416     {
 417       riscv_override_options_internal (&global_options);
 418       new_target = build_target_option_node (&global_options,
 419                                              &global_options_set);
 420       DECL_FUNCTION_SPECIFIC_TARGET (fndecl) = new_target;
 421     }
 422
 423   /* Restore current target options to original state.  */
 424   cl_target_option_restore (&global_options, &global_options_set, &cur_target);
 425   return ret;
 426 }