gcc/cp/g++spec.cc

   1 /* Specific flags and argument handling of the C++ front end.
   2    Copyright (C) 1996-2024 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 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "tm.h"
  24 #include "opts.h"
  25
  26 /* This bit is set if we saw a `-xfoo' language specification.  */
  27 #define LANGSPEC        (1<<1)
  28 /* This bit is set if they did `-lm' or `-lmath'.  */
  29 #define MATHLIB         (1<<2)
  30 /* This bit is set if they did `-lc'.  */
  31 #define WITHLIBC        (1<<3)
  32 /* Skip this option.  */
  33 #define SKIPOPT         (1<<4)
  34 /* Add -lstdc++exp for experimental features that need library support.  */
  35 #define EXPERIMENTAL    (1<<5)
  36
  37 #ifndef MATH_LIBRARY
  38 #define MATH_LIBRARY "m"
  39 #endif
  40 #ifndef MATH_LIBRARY_PROFILE
  41 #define MATH_LIBRARY_PROFILE MATH_LIBRARY
  42 #endif
  43
  44 #ifndef LIBSTDCXX
  45 #define LIBSTDCXX "stdc++"
  46 #endif
  47 #ifndef LIBSTDCXX_PROFILE
  48 #define LIBSTDCXX_PROFILE LIBSTDCXX
  49 #endif
  50 #ifndef LIBSTDCXX_STATIC
  51 #define LIBSTDCXX_STATIC NULL
  52 #endif
  53
  54 #ifndef LIBCXX
  55 #define LIBCXX "c++"
  56 #endif
  57 #ifndef LIBCXX_PROFILE
  58 #define LIBCXX_PROFILE LIBCXX
  59 #endif
  60 #ifndef LIBCXX_STATIC
  61 #define LIBCXX_STATIC NULL
  62 #endif
  63
  64 #ifndef LIBCXXABI
  65 #define LIBCXXABI "c++abi"
  66 #endif
  67 #ifndef LIBCXXABI_PROFILE
  68 #define LIBCXXABI_PROFILE LIBCXXABI
  69 #endif
  70 #ifndef LIBCXXABI_STATIC
  71 #define LIBCXXABI_STATIC NULL
  72 #endif
  73
  74 /* The values used here must match those of the stdlib_kind enumeration
  75    in c.opt.  */
  76 enum stdcxxlib_kind
  77 {
  78   USE_LIBSTDCXX = 1,
  79   USE_LIBCXX = 2
  80 };
  81
  82 void
  83 lang_specific_driver (struct cl_decoded_option **in_decoded_options,
  84                       unsigned int *in_decoded_options_count,
  85                       int *in_added_libraries)
  86 {
  87   unsigned int i, j;
  88
  89   /* If nonzero, the user gave us the `-p' or `-pg' flag.  */
  90   int saw_profile_flag = 0;
  91
  92   /* What action to take for the c++ runtime library:
  93     -1  means we should not link it in.
  94      0  means we should link it if it is needed.
  95      1  means it is needed and should be linked in.
  96      2  means it is needed but should be linked statically.  */
  97   int library = 0;
  98
  99   /* Which c++ runtime library to link.  */
 100   stdcxxlib_kind which_library = USE_LIBSTDCXX;
 101
 102   /* The number of arguments being added to what's in argv, other than
 103      libraries.  We use this to track the number of times we've inserted
 104      -xc++/-xnone.  */
 105   int added = 0;
 106
 107   /* The new argument list will be contained in this.  */
 108   struct cl_decoded_option *new_decoded_options;
 109
 110   /* Nonzero if we saw a `-xfoo' language specification on the
 111      command line.  Used to avoid adding our own -xc++ if the user
 112      already gave a language for the file.  */
 113   int saw_speclang = 0;
 114
 115   /* "-lm" or "-lmath" if it appears on the command line.  */
 116   const struct cl_decoded_option *saw_math = NULL;
 117
 118   /* "-lrt" or eqivalent if it appears on the command line.  */
 119   const struct cl_decoded_option *saw_time = NULL;
 120
 121   /* "-lc" if it appears on the command line.  */
 122   const struct cl_decoded_option *saw_libc = NULL;
 123
 124   /* An array used to flag each argument that needs a bit set for
 125      LANGSPEC, MATHLIB, or WITHLIBC.  */
 126   int *args;
 127
 128   /* By default, we throw on the math library if we have one.  */
 129   int need_math = (MATH_LIBRARY[0] != '\0');
 130
 131   /* By default, we don't add -lstdc++exp.  */
 132   bool need_experimental = false;
 133
 134   /* True if we saw -static.  */
 135   int static_link = 0;
 136
 137   /* True if we should add -shared-libgcc to the command-line.  */
 138   int shared_libgcc = 1;
 139
 140   /* The total number of arguments with the new stuff.  */
 141   unsigned int argc;
 142
 143   /* The argument list.  */
 144   struct cl_decoded_option *decoded_options;
 145
 146   /* The number of libraries added in.  */
 147   int added_libraries;
 148
 149   /* The total number of arguments with the new stuff.  */
 150   unsigned int num_args = 1;
 151
 152   argc = *in_decoded_options_count;
 153   decoded_options = *in_decoded_options;
 154   added_libraries = *in_added_libraries;
 155
 156   args = XCNEWVEC (int, argc);
 157
 158   for (i = 1; i < argc; i++)
 159     {
 160       const char *arg = decoded_options[i].arg;
 161       if (decoded_options[i].errors & CL_ERR_MISSING_ARG)
 162         continue; /* Avoid examining arguments of options missing them.  */
 163
 164       switch (decoded_options[i].opt_index)
 165         {
 166         case OPT_fcontracts:
 167           need_experimental = true;
 168           break;
 169
 170         case OPT_nostdlib__:
 171           args[i] |= SKIPOPT;
 172           /* FALLTHRU */
 173         case OPT_nostdlib:
 174         case OPT_nodefaultlibs:
 175           library = -1;
 176           break;
 177
 178         case OPT_l:
 179           if (strcmp (arg, MATH_LIBRARY) == 0)
 180             {
 181               args[i] |= MATHLIB;
 182               need_math = 0;
 183             }
 184           else if (strcmp (arg, "c") == 0)
 185             args[i] |= WITHLIBC;
 186           else
 187             /* Unrecognized libraries (e.g. -lfoo) may require libstdc++.  */
 188             library = (library == 0) ? 1 : library;
 189           break;
 190
 191         case OPT_pg:
 192         case OPT_p:
 193           saw_profile_flag++;
 194           break;
 195
 196         case OPT_x:
 197           if (library == 0
 198               && (strcmp (arg, "c++") == 0
 199                   || strcmp (arg, "c++-cpp-output") == 0
 200                   || strcmp (arg, "objective-c++") == 0
 201                   || strcmp (arg, "objective-c++-cpp-output") == 0))
 202             library = 1;
 203
 204           saw_speclang = 1;
 205           break;
 206
 207         case OPT_Xlinker:
 208         case OPT_Wl_:
 209           /* Arguments that go directly to the linker might be .o files,
 210              or something, and so might cause libstdc++ to be needed.  */
 211           if (library == 0)
 212             library = 1;
 213           break;
 214
 215         case OPT_c:
 216         case OPT_r:
 217         case OPT_S:
 218         case OPT_E:
 219         case OPT_M:
 220         case OPT_MM:
 221         case OPT_fsyntax_only:
 222           /* Don't specify libraries if we won't link, since that would
 223              cause a warning.  */
 224           library = -1;
 225           break;
 226
 227         case OPT_static:
 228           static_link = 1;
 229           break;
 230
 231         case OPT_static_libgcc:
 232           shared_libgcc = 0;
 233           break;
 234
 235         case OPT_static_libstdc__:
 236           library = library >= 0 ? 2 : library;
 237 #ifdef HAVE_LD_STATIC_DYNAMIC
 238           /* Remove -static-libstdc++ from the command only if target supports
 239              LD_STATIC_DYNAMIC.  When not supported, it is left in so that a
 240              back-end target can use outfile substitution.  */
 241           args[i] |= SKIPOPT;
 242 #endif
 243           break;
 244
 245         case OPT_stdlib_:
 246           which_library = (stdcxxlib_kind) decoded_options[i].value;
 247           break;
 248
 249         case OPT_SPECIAL_input_file:
 250           {
 251             int len;
 252
 253             /* We don't do this anymore, since we don't get them with minus
 254                signs on them.  */
 255             if (arg[0] == '\0' || arg[1] == '\0')
 256               continue;
 257
 258             if (saw_speclang)
 259               {
 260                 saw_speclang = 0;
 261                 continue;
 262               }
 263
 264             /* If the filename ends in .[chi], put options around it.
 265                But not if a specified -x option is currently active.  */
 266             len = strlen (arg);
 267             if (len > 2
 268                 && (arg[len - 1] == 'c'
 269                     || arg[len - 1] == 'i'
 270                     || arg[len - 1] == 'h')
 271                 && arg[len - 2] == '.')
 272               {
 273                 args[i] |= LANGSPEC;
 274                 added += 2;
 275               }
 276
 277             /* If we don't know that this is a header file, we might
 278                need to be linking in the libraries.  */
 279             if (library == 0)
 280               {
 281                 if ((len <= 2 || strcmp (arg + (len - 2), ".H") != 0)
 282                     && (len <= 2 || strcmp (arg + (len - 2), ".h") != 0)
 283                     && (len <= 4 || strcmp (arg + (len - 4), ".hpp") != 0)
 284                     && (len <= 3 || strcmp (arg + (len - 3), ".hp") != 0)
 285                     && (len <= 4 || strcmp (arg + (len - 4), ".hxx") != 0)
 286                     && (len <= 4 || strcmp (arg + (len - 4), ".h++") != 0)
 287                     && (len <= 4 || strcmp (arg + (len - 4), ".HPP") != 0)
 288                     && (len <= 4 || strcmp (arg + (len - 4), ".tcc") != 0)
 289                     && (len <= 3 || strcmp (arg + (len - 3), ".hh") != 0))
 290                   library = 1;
 291               }
 292           }
 293           break;
 294         }
 295     }
 296
 297   /* There's no point adding -shared-libgcc if we don't have a shared
 298      libgcc.  */
 299 #ifndef ENABLE_SHARED_LIBGCC
 300   shared_libgcc = 0;
 301 #endif
 302
 303   /* Add one for shared_libgcc or extra static library.  */
 304   num_args = (argc + added + need_math + need_experimental
 305               + (library > 0) * 4 + 1);
 306   /* For libc++, on most platforms, the ABI library (usually called libc++abi)
 307      is provided as a separate DSO, which we must also append.
 308      However, a platform might have the ability to forward the ABI library
 309      from libc++, or combine it in some other way; in that case, LIBCXXABI
 310      should be set to NULL to signal that it need not be appended.  */
 311   if (which_library == USE_LIBCXX && LIBCXXABI != NULL)
 312     num_args += 4;
 313   new_decoded_options = XNEWVEC (struct cl_decoded_option, num_args);
 314
 315   i = 0;
 316   j = 0;
 317
 318   /* Copy the 0th argument, i.e., the name of the program itself.  */
 319   new_decoded_options[j++] = decoded_options[i++];
 320
 321   /* NOTE: We start at 1 now, not 0.  */
 322   while (i < argc)
 323     {
 324       new_decoded_options[j] = decoded_options[i];
 325
 326       /* Make sure -lstdc++ is before the math library, since libstdc++
 327          itself uses those math routines.  */
 328       if (!saw_math && (args[i] & MATHLIB) && library > 0)
 329         {
 330           --j;
 331           saw_math = &decoded_options[i];
 332         }
 333
 334       if (!saw_libc && (args[i] & WITHLIBC) && library > 0)
 335         {
 336           --j;
 337           saw_libc = &decoded_options[i];
 338         }
 339
 340       /* Wrap foo.[chi] files in a language specification to
 341          force the gcc compiler driver to run cc1plus on them.  */
 342       if (args[i] & LANGSPEC)
 343         {
 344           const char *arg = decoded_options[i].arg;
 345           int len = strlen (arg);
 346           switch (arg[len - 1])
 347             {
 348             case 'c':
 349               generate_option (OPT_x, "c++", 1, CL_DRIVER,
 350                                &new_decoded_options[j++]);
 351               break;
 352             case 'i':
 353               generate_option (OPT_x, "c++-cpp-output", 1, CL_DRIVER,
 354                                &new_decoded_options[j++]);
 355               break;
 356             case 'h':
 357               generate_option (OPT_x, "c++-header", 1, CL_DRIVER,
 358                                &new_decoded_options[j++]);
 359               break;
 360             default:
 361               gcc_unreachable ();
 362             }
 363           new_decoded_options[j++] = decoded_options[i];
 364           generate_option (OPT_x, "none", 1, CL_DRIVER,
 365                            &new_decoded_options[j]);
 366         }
 367
 368       if ((args[i] & SKIPOPT) != 0)
 369         --j;
 370
 371       i++;
 372       j++;
 373     }
 374
 375   /* Add `-lstdc++' if we haven't already done so.  */
 376   if (library > 0)
 377     {
 378       if (need_experimental && which_library == USE_LIBSTDCXX)
 379         {
 380           generate_option (OPT_l, "stdc++exp", 1, CL_DRIVER,
 381                            &new_decoded_options[j++]);
 382           ++added_libraries;
 383         }
 384 #ifdef HAVE_LD_STATIC_DYNAMIC
 385       if (library > 1 && !static_link)
 386         {
 387           generate_option (OPT_Wl_, LD_STATIC_OPTION, 1, CL_DRIVER,
 388                            &new_decoded_options[j]);
 389           j++;
 390         }
 391 #endif
 392       if (which_library == USE_LIBCXX)
 393         {
 394           generate_option (OPT_l,
 395                          saw_profile_flag ? LIBCXX_PROFILE : LIBCXX, 1,
 396                          CL_DRIVER, &new_decoded_options[j]);
 397           if (LIBCXXABI != NULL)
 398             {
 399               j++;
 400               added_libraries++;
 401               generate_option (OPT_l,
 402                                saw_profile_flag ? LIBCXXABI_PROFILE
 403                                                 : LIBCXXABI, 1,
 404                                CL_DRIVER, &new_decoded_options[j]);
 405             }
 406         }
 407       else
 408         generate_option (OPT_l,
 409                          saw_profile_flag ? LIBSTDCXX_PROFILE : LIBSTDCXX, 1,
 410                          CL_DRIVER, &new_decoded_options[j]);
 411       added_libraries++;
 412       j++;
 413       /* Add target-dependent static library, if necessary.  */
 414       if ((static_link || library > 1) && LIBSTDCXX_STATIC != NULL)
 415         {
 416           generate_option (OPT_l, LIBSTDCXX_STATIC, 1,
 417                            CL_DRIVER, &new_decoded_options[j]);
 418           added_libraries++;
 419           j++;
 420         }
 421 #ifdef HAVE_LD_STATIC_DYNAMIC
 422       if (library > 1 && !static_link)
 423         {
 424           generate_option (OPT_Wl_, LD_DYNAMIC_OPTION, 1, CL_DRIVER,
 425                            &new_decoded_options[j]);
 426           j++;
 427         }
 428 #endif
 429     }
 430   if (saw_math)
 431     new_decoded_options[j++] = *saw_math;
 432   else if (library > 0 && need_math)
 433     {
 434       generate_option (OPT_l,
 435                        saw_profile_flag ? MATH_LIBRARY_PROFILE : MATH_LIBRARY,
 436                        1, CL_DRIVER, &new_decoded_options[j]);
 437       added_libraries++;
 438       j++;
 439     }
 440   if (saw_time)
 441     new_decoded_options[j++] = *saw_time;
 442   if (saw_libc)
 443     new_decoded_options[j++] = *saw_libc;
 444   if (shared_libgcc && !static_link)
 445     generate_option (OPT_shared_libgcc, NULL, 1, CL_DRIVER,
 446                      &new_decoded_options[j++]);
 447
 448   *in_decoded_options_count = j;
 449   *in_decoded_options = new_decoded_options;
 450   *in_added_libraries = added_libraries;
 451 }
 452
 453 /* Called before linking.  Returns 0 on success and -1 on failure.  */
 454 int lang_specific_pre_link (void)  /* Not used for C++.  */
 455 {
 456   return 0;
 457 }
 458
 459 /* Number of extra output files that lang_specific_pre_link may generate.  */
 460 int lang_specific_extra_outfiles = 0;  /* Not used for C++.  */