gcc/go/gospec.cc

   1 /* gospec.cc -- Specific flags and argument handling of the gcc Go front end.
   2    Copyright (C) 2009-2024 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 it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 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 `-lpthread'.  */
  31 #define THREADLIB       (1<<3)
  32 /* This bit is set if they did `-lc'.  */
  33 #define WITHLIBC        (1<<4)
  34 /* Skip this option.  */
  35 #define SKIPOPT         (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 #define THREAD_LIBRARY "pthread"
  45 #define THREAD_LIBRARY_PROFILE THREAD_LIBRARY
  46
  47 #define LIBGO "go"
  48 #define LIBGO_PROFILE LIBGO
  49 #define LIBGOBEGIN "gobegin"
  50
  51 void
  52 lang_specific_driver (struct cl_decoded_option **in_decoded_options,
  53                       unsigned int *in_decoded_options_count,
  54                       int *in_added_libraries)
  55 {
  56   unsigned int i, j;
  57
  58   /* If true, the user gave us the `-p' or `-pg' flag.  */
  59   bool saw_profile_flag = false;
  60
  61   /* This is a tristate:
  62      -1 means we should not link in libgo
  63      0  means we should link in libgo if it is needed
  64      1  means libgo is needed and should be linked in.
  65      2  means libgo is needed and should be linked statically.  */
  66   int library = 0;
  67
  68   /* The new argument list will be contained in this.  */
  69   struct cl_decoded_option *new_decoded_options;
  70
  71   /* "-lm" or "-lmath" if it appears on the command line.  */
  72   const struct cl_decoded_option *saw_math = 0;
  73
  74   /* "-lpthread" if it appears on the command line.  */
  75   const struct cl_decoded_option *saw_thread = 0;
  76
  77   /* "-lc" if it appears on the command line.  */
  78   const struct cl_decoded_option *saw_libc = 0;
  79
  80   /* An array used to flag each argument that needs a bit set for
  81      LANGSPEC, MATHLIB, or WITHLIBC.  */
  82   int *args;
  83
  84   /* Whether we need the thread library.  */
  85   int need_thread = 0;
  86
  87   /* By default, we throw on the math library if we have one.  */
  88   int need_math = (MATH_LIBRARY[0] != '\0');
  89
  90   /* True if we saw -static.  */
  91   int static_link = 0;
  92
  93   /* True if we should add -shared-libgcc to the command-line.  */
  94   int shared_libgcc = 1;
  95
  96   /* The total number of arguments with the new stuff.  */
  97   unsigned int argc;
  98
  99   /* The argument list.  */
 100   struct cl_decoded_option *decoded_options;
 101
 102   /* The number of libraries added in.  */
 103   int added_libraries;
 104
 105   /* The total number of arguments with the new stuff.  */
 106   int num_args = 1;
 107
 108   /* Supports split stack */
 109   int supports_split_stack = 0;
 110
 111   /* Whether the -o option was used.  */
 112   bool saw_opt_o = false;
 113
 114   /* Whether the -c option was used.  Also used for -E, -fsyntax-only,
 115      in general anything which implies only compilation and not
 116      linking.  */
 117   bool saw_opt_c = false;
 118
 119   /* Whether the -S option was used.  */
 120   bool saw_opt_S = false;
 121
 122 #ifdef TARGET_CAN_SPLIT_STACK_64BIT
 123   /* Whether the -m64 option is in force. */
 124   bool is_m64 = TARGET_CAN_SPLIT_STACK_64BIT;
 125 #endif
 126
 127   /* The first input file with an extension of .go.  */
 128   const char *first_go_file = NULL;
 129
 130   /* Whether we saw any -g option.  */
 131   bool saw_opt_g = false;
 132
 133   argc = *in_decoded_options_count;
 134   decoded_options = *in_decoded_options;
 135   added_libraries = *in_added_libraries;
 136
 137   args = XCNEWVEC (int, argc);
 138
 139   for (i = 1; i < argc; i++)
 140     {
 141       const char *arg = decoded_options[i].arg;
 142
 143       switch (decoded_options[i].opt_index)
 144         {
 145         case OPT_r:
 146         case OPT_nostdlib:
 147         case OPT_nodefaultlibs:
 148           library = -1;
 149           break;
 150
 151         case OPT_l:
 152           if (strcmp (arg, MATH_LIBRARY) == 0)
 153             {
 154               args[i] |= MATHLIB;
 155               need_math = 0;
 156             }
 157           else if (strcmp (arg, THREAD_LIBRARY) == 0)
 158             args[i] |= THREADLIB;
 159           else if (strcmp (arg, "c") == 0)
 160             args[i] |= WITHLIBC;
 161           else
 162             /* Unrecognized libraries (e.g. -lfoo) may require libgo.  */
 163             library = (library == 0) ? 1 : library;
 164           break;
 165
 166 #ifdef TARGET_CAN_SPLIT_STACK_64BIT
 167         case OPT_m32:
 168           is_m64 = false;
 169           break;
 170
 171         case OPT_m64:
 172           is_m64 = true;
 173           break;
 174 #endif
 175
 176         case OPT_pg:
 177         case OPT_p:
 178           saw_profile_flag = true;
 179           break;
 180
 181         case OPT_x:
 182           if (library == 0 && strcmp (arg, "go") == 0)
 183             library = 1;
 184           break;
 185
 186         case OPT_Xlinker:
 187         case OPT_Wl_:
 188           /* Arguments that go directly to the linker might be .o files,
 189              or something, and so might cause libgo to be needed.  */
 190           if (library == 0)
 191             library = 1;
 192           break;
 193
 194         case OPT_c:
 195         case OPT_E:
 196         case OPT_M:
 197         case OPT_MM:
 198         case OPT_fsyntax_only:
 199           /* Don't specify libraries if we won't link, since that would
 200              cause a warning.  */
 201           saw_opt_c = true;
 202           library = -1;
 203           break;
 204
 205         case OPT_S:
 206           saw_opt_S = true;
 207           library = -1;
 208           break;
 209
 210         case OPT_o:
 211           saw_opt_o = true;
 212           break;
 213
 214         case OPT_g:
 215         case OPT_gdwarf:
 216         case OPT_gdwarf_:
 217         case OPT_ggdb:
 218         case OPT_gvms:
 219           saw_opt_g = true;
 220           break;
 221
 222         case OPT_static:
 223           static_link = 1;
 224           break;
 225
 226         case OPT_static_libgcc:
 227           shared_libgcc = 0;
 228           break;
 229
 230         case OPT_static_libgo:
 231           library = library >= 0 ? 2 : library;
 232           args[i] |= SKIPOPT;
 233           break;
 234
 235         case OPT_SPECIAL_input_file:
 236           if (library == 0)
 237             library = 1;
 238
 239           if (first_go_file == NULL)
 240             {
 241               int len;
 242
 243               len = strlen (arg);
 244               if (len > 3 && strcmp (arg + len - 3, ".go") == 0)
 245                 first_go_file = arg;
 246             }
 247
 248           break;
 249         }
 250     }
 251
 252   /* There's no point adding -shared-libgcc if we don't have a shared
 253      libgcc.  */
 254 #ifndef ENABLE_SHARED_LIBGCC
 255   shared_libgcc = 0;
 256 #endif
 257
 258   /* Make sure to have room for the trailing NULL argument.  */
 259   num_args = argc + need_math + shared_libgcc + (library > 0) * 5 + 10;
 260   new_decoded_options = XNEWVEC (struct cl_decoded_option, num_args);
 261
 262   i = 0;
 263   j = 0;
 264
 265   /* Copy the 0th argument, i.e., the name of the program itself.  */
 266   new_decoded_options[j++] = decoded_options[i++];
 267
 268 #ifdef TARGET_CAN_SPLIT_STACK
 269   supports_split_stack = 1;
 270 #endif
 271
 272 #ifdef TARGET_CAN_SPLIT_STACK_64BIT
 273   if (is_m64)
 274     supports_split_stack = 1;
 275 #endif
 276
 277   /* If we are linking, pass -fsplit-stack if it is supported.  */
 278   if ((library >= 0) && supports_split_stack)
 279     {
 280       generate_option (OPT_fsplit_stack, NULL, 1, CL_DRIVER,
 281                        &new_decoded_options[j]);
 282       j++;
 283     }
 284
 285   /* The go1 compiler is going to enable debug info by default.  If we
 286      don't see any -g options, force -g, so that we invoke the
 287      assembler with the right debug option.  */
 288   if (!saw_opt_g)
 289     {
 290       generate_option (OPT_g, "1", 0, CL_DRIVER, &new_decoded_options[j]);
 291       j++;
 292     }
 293
 294   /* NOTE: We start at 1 now, not 0.  */
 295   while (i < argc)
 296     {
 297       new_decoded_options[j] = decoded_options[i];
 298
 299       /* Make sure -lgo is before the math library, since libgo itself
 300          uses those math routines.  */
 301       if (!saw_math && (args[i] & MATHLIB) && library > 0)
 302         {
 303           --j;
 304           saw_math = &decoded_options[i];
 305         }
 306
 307       if (!saw_thread && (args[i] & THREADLIB) && library > 0)
 308         {
 309           --j;
 310           saw_thread = &decoded_options[i];
 311         }
 312
 313       if (!saw_libc && (args[i] & WITHLIBC) && library > 0)
 314         {
 315           --j;
 316           saw_libc = &decoded_options[i];
 317         }
 318
 319       if ((args[i] & SKIPOPT) != 0)
 320         --j;
 321
 322       i++;
 323       j++;
 324     }
 325
 326   /* If we didn't see a -o option, add one.  This is because we need
 327      the driver to pass all .go files to go1.  Without a -o option the
 328      driver will invoke go1 separately for each input file.  FIXME:
 329      This should probably use some other interface to force the driver
 330      to set combine_inputs.  */
 331   if (first_go_file != NULL && !saw_opt_o)
 332     {
 333       if (saw_opt_c || saw_opt_S)
 334         {
 335           const char *base;
 336           int baselen;
 337           int alen;
 338           char *out;
 339
 340           base = lbasename (first_go_file);
 341           baselen = strlen (base) - 3;
 342           alen = baselen + 3;
 343           out = XNEWVEC (char, alen);
 344           memcpy (out, base, baselen);
 345           /* The driver will convert .o to some other suffix (e.g.,
 346              .obj) if appropriate.  */
 347           out[baselen] = '.';
 348           if (saw_opt_S)
 349             out[baselen + 1] = 's';
 350           else
 351             out[baselen + 1] = 'o';
 352           out[baselen + 2] = '\0';
 353           generate_option (OPT_o, out, 1, CL_DRIVER,
 354                            &new_decoded_options[j]);
 355         }
 356       else
 357         generate_option (OPT_o, "a.out", 1, CL_DRIVER,
 358                          &new_decoded_options[j]);
 359       j++;
 360     }
 361
 362   /* Add `-lgo' if we haven't already done so.  */
 363   if (library > 0)
 364     {
 365       generate_option (OPT_l, LIBGOBEGIN, 1, CL_DRIVER,
 366                        &new_decoded_options[j]);
 367       added_libraries++;
 368       j++;
 369
 370 #ifdef HAVE_LD_STATIC_DYNAMIC
 371       if (library > 1 && !static_link)
 372         {
 373           generate_option (OPT_Wl_, LD_STATIC_OPTION, 1, CL_DRIVER,
 374                            &new_decoded_options[j]);
 375           j++;
 376         }
 377 #endif
 378
 379       generate_option (OPT_l, saw_profile_flag ? LIBGO_PROFILE : LIBGO, 1,
 380                        CL_DRIVER, &new_decoded_options[j]);
 381       added_libraries++;
 382       j++;
 383
 384 #ifdef HAVE_LD_STATIC_DYNAMIC
 385       if (library > 1 && !static_link)
 386         {
 387           generate_option (OPT_Wl_, LD_DYNAMIC_OPTION, 1, CL_DRIVER,
 388                            &new_decoded_options[j]);
 389           j++;
 390         }
 391 #endif
 392
 393       /* When linking libgo statically we also need to link with the
 394          pthread library.  */
 395       if (library > 1 || static_link)
 396         need_thread = 1;
 397     }
 398
 399   if (saw_thread)
 400     new_decoded_options[j++] = *saw_thread;
 401   else if (library > 0 && need_thread)
 402     {
 403       generate_option (OPT_l,
 404                        (saw_profile_flag
 405                         ? THREAD_LIBRARY_PROFILE
 406                         : THREAD_LIBRARY),
 407                        1, CL_DRIVER, &new_decoded_options[j]);
 408       added_libraries++;
 409       j++;
 410     }
 411
 412   if (saw_math)
 413     new_decoded_options[j++] = *saw_math;
 414   else if (library > 0 && need_math)
 415     {
 416       generate_option (OPT_l,
 417                        saw_profile_flag ? MATH_LIBRARY_PROFILE : MATH_LIBRARY,
 418                        1, CL_DRIVER, &new_decoded_options[j]);
 419       added_libraries++;
 420       j++;
 421     }
 422
 423   if (saw_libc)
 424     new_decoded_options[j++] = *saw_libc;
 425   if (shared_libgcc && !static_link)
 426     generate_option (OPT_shared_libgcc, NULL, 1, CL_DRIVER,
 427                      &new_decoded_options[j++]);
 428
 429   /* libgcc wraps pthread_create to support split stack, however, due to
 430      relative ordering of -lpthread and -lgcc, we can't just mark
 431      __real_pthread_create in libgcc as non-weak.  But we need to link in
 432      pthread_create from pthread if we are statically linking, so we work-
 433      around by passing -u pthread_create to the linker. */
 434   if (static_link && supports_split_stack)
 435     {
 436       generate_option (OPT_Wl_, "-u,pthread_create", 1, CL_DRIVER,
 437                        &new_decoded_options[j]);
 438       j++;
 439     }
 440
 441 #if defined(TARGET_SOLARIS) && !defined(USE_GLD)
 442   /* We use a common symbol for go$zerovalue.  On Solaris, when not
 443      using the GNU linker, the Solaris linker needs an option to not
 444      warn about this.  Everything works without this option, but you
 445      get unsightly warnings at link time.  */
 446   generate_option (OPT_Wl_, "-t", 1, CL_DRIVER, &new_decoded_options[j]);
 447   j++;
 448 #endif
 449
 450   *in_decoded_options_count = j;
 451   *in_decoded_options = new_decoded_options;
 452   *in_added_libraries = added_libraries;
 453 }
 454
 455 /* Called before linking.  Returns 0 on success and -1 on failure.  */
 456 int lang_specific_pre_link (void)  /* Not used for Go.  */
 457 {
 458   return 0;
 459 }
 460
 461 /* Number of extra output files that lang_specific_pre_link may generate.  */
 462 int lang_specific_extra_outfiles = 0;  /* Not used for Go.  */