gcc/go/gospec.c

   1 /* gospec.c -- Specific flags and argument handling of the gcc Go front end.
   2    Copyright (C) 2009-2019 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   argc = *in_decoded_options_count;
 131   decoded_options = *in_decoded_options;
 132   added_libraries = *in_added_libraries;
 133
 134   args = XCNEWVEC (int, argc);
 135
 136   for (i = 1; i < argc; i++)
 137     {
 138       const char *arg = decoded_options[i].arg;
 139
 140       switch (decoded_options[i].opt_index)
 141         {
 142         case OPT_r:
 143         case OPT_nostdlib:
 144         case OPT_nodefaultlibs:
 145           library = -1;
 146           break;
 147
 148         case OPT_l:
 149           if (strcmp (arg, MATH_LIBRARY) == 0)
 150             {
 151               args[i] |= MATHLIB;
 152               need_math = 0;
 153             }
 154           else if (strcmp (arg, THREAD_LIBRARY) == 0)
 155             args[i] |= THREADLIB;
 156           else if (strcmp (arg, "c") == 0)
 157             args[i] |= WITHLIBC;
 158           else
 159             /* Unrecognized libraries (e.g. -lfoo) may require libgo.  */
 160             library = (library == 0) ? 1 : library;
 161           break;
 162
 163 #ifdef TARGET_CAN_SPLIT_STACK_64BIT
 164         case OPT_m32:
 165           is_m64 = false;
 166           break;
 167
 168         case OPT_m64:
 169           is_m64 = true;
 170           break;
 171 #endif
 172
 173         case OPT_pg:
 174         case OPT_p:
 175           saw_profile_flag = true;
 176           break;
 177
 178         case OPT_x:
 179           if (library == 0 && strcmp (arg, "go") == 0)
 180             library = 1;
 181           break;
 182
 183         case OPT_Xlinker:
 184         case OPT_Wl_:
 185           /* Arguments that go directly to the linker might be .o files,
 186              or something, and so might cause libgo to be needed.  */
 187           if (library == 0)
 188             library = 1;
 189           break;
 190
 191         case OPT_c:
 192         case OPT_E:
 193         case OPT_M:
 194         case OPT_MM:
 195         case OPT_fsyntax_only:
 196           /* Don't specify libraries if we won't link, since that would
 197              cause a warning.  */
 198           saw_opt_c = true;
 199           library = -1;
 200           break;
 201
 202         case OPT_S:
 203           saw_opt_S = true;
 204           library = -1;
 205           break;
 206
 207         case OPT_o:
 208           saw_opt_o = true;
 209           break;
 210
 211         case OPT_static:
 212           static_link = 1;
 213           break;
 214
 215         case OPT_static_libgcc:
 216           shared_libgcc = 0;
 217           break;
 218
 219         case OPT_static_libgo:
 220           library = library >= 0 ? 2 : library;
 221           args[i] |= SKIPOPT;
 222           break;
 223
 224         case OPT_SPECIAL_input_file:
 225           if (library == 0)
 226             library = 1;
 227
 228           if (first_go_file == NULL)
 229             {
 230               int len;
 231
 232               len = strlen (arg);
 233               if (len > 3 && strcmp (arg + len - 3, ".go") == 0)
 234                 first_go_file = arg;
 235             }
 236
 237           break;
 238         }
 239     }
 240
 241   /* There's no point adding -shared-libgcc if we don't have a shared
 242      libgcc.  */
 243 #ifndef ENABLE_SHARED_LIBGCC
 244   shared_libgcc = 0;
 245 #endif
 246
 247   /* Make sure to have room for the trailing NULL argument.  */
 248   num_args = argc + need_math + shared_libgcc + (library > 0) * 5 + 10;
 249   new_decoded_options = XNEWVEC (struct cl_decoded_option, num_args);
 250
 251   i = 0;
 252   j = 0;
 253
 254   /* Copy the 0th argument, i.e., the name of the program itself.  */
 255   new_decoded_options[j++] = decoded_options[i++];
 256
 257 #ifdef TARGET_CAN_SPLIT_STACK
 258   supports_split_stack = 1;
 259 #endif
 260
 261 #ifdef TARGET_CAN_SPLIT_STACK_64BIT
 262   if (is_m64)
 263     supports_split_stack = 1;
 264 #endif
 265
 266   /* If we are linking, pass -fsplit-stack if it is supported.  */
 267   if ((library >= 0) && supports_split_stack)
 268     {
 269       generate_option (OPT_fsplit_stack, NULL, 1, CL_DRIVER,
 270                        &new_decoded_options[j]);
 271       j++;
 272     }
 273
 274   /* NOTE: We start at 1 now, not 0.  */
 275   while (i < argc)
 276     {
 277       new_decoded_options[j] = decoded_options[i];
 278
 279       /* Make sure -lgo is before the math library, since libgo itself
 280          uses those math routines.  */
 281       if (!saw_math && (args[i] & MATHLIB) && library > 0)
 282         {
 283           --j;
 284           saw_math = &decoded_options[i];
 285         }
 286
 287       if (!saw_thread && (args[i] & THREADLIB) && library > 0)
 288         {
 289           --j;
 290           saw_thread = &decoded_options[i];
 291         }
 292
 293       if (!saw_libc && (args[i] & WITHLIBC) && library > 0)
 294         {
 295           --j;
 296           saw_libc = &decoded_options[i];
 297         }
 298
 299       if ((args[i] & SKIPOPT) != 0)
 300         --j;
 301
 302       i++;
 303       j++;
 304     }
 305
 306   /* If we didn't see a -o option, add one.  This is because we need
 307      the driver to pass all .go files to go1.  Without a -o option the
 308      driver will invoke go1 separately for each input file.  FIXME:
 309      This should probably use some other interface to force the driver
 310      to set combine_inputs.  */
 311   if (first_go_file != NULL && !saw_opt_o)
 312     {
 313       if (saw_opt_c || saw_opt_S)
 314         {
 315           const char *base;
 316           int baselen;
 317           int alen;
 318           char *out;
 319
 320           base = lbasename (first_go_file);
 321           baselen = strlen (base) - 3;
 322           alen = baselen + 3;
 323           out = XNEWVEC (char, alen);
 324           memcpy (out, base, baselen);
 325           /* The driver will convert .o to some other suffix (e.g.,
 326              .obj) if appropriate.  */
 327           out[baselen] = '.';
 328           if (saw_opt_S)
 329             out[baselen + 1] = 's';
 330           else
 331             out[baselen + 1] = 'o';
 332           out[baselen + 2] = '\0';
 333           generate_option (OPT_o, out, 1, CL_DRIVER,
 334                            &new_decoded_options[j]);
 335         }
 336       else
 337         generate_option (OPT_o, "a.out", 1, CL_DRIVER,
 338                          &new_decoded_options[j]);
 339       j++;
 340     }
 341
 342   /* Add `-lgo' if we haven't already done so.  */
 343   if (library > 0)
 344     {
 345       generate_option (OPT_l, LIBGOBEGIN, 1, CL_DRIVER,
 346                        &new_decoded_options[j]);
 347       added_libraries++;
 348       j++;
 349
 350 #ifdef HAVE_LD_STATIC_DYNAMIC
 351       if (library > 1 && !static_link)
 352         {
 353           generate_option (OPT_Wl_, LD_STATIC_OPTION, 1, CL_DRIVER,
 354                            &new_decoded_options[j]);
 355           j++;
 356         }
 357 #endif
 358
 359       generate_option (OPT_l, saw_profile_flag ? LIBGO_PROFILE : LIBGO, 1,
 360                        CL_DRIVER, &new_decoded_options[j]);
 361       added_libraries++;
 362       j++;
 363
 364 #ifdef HAVE_LD_STATIC_DYNAMIC
 365       if (library > 1 && !static_link)
 366         {
 367           generate_option (OPT_Wl_, LD_DYNAMIC_OPTION, 1, CL_DRIVER,
 368                            &new_decoded_options[j]);
 369           j++;
 370         }
 371 #endif
 372
 373       /* When linking libgo statically we also need to link with the
 374          pthread library.  */
 375       if (library > 1 || static_link)
 376         need_thread = 1;
 377     }
 378
 379   if (saw_thread)
 380     new_decoded_options[j++] = *saw_thread;
 381   else if (library > 0 && need_thread)
 382     {
 383       generate_option (OPT_l,
 384                        (saw_profile_flag
 385                         ? THREAD_LIBRARY_PROFILE
 386                         : THREAD_LIBRARY),
 387                        1, CL_DRIVER, &new_decoded_options[j]);
 388       added_libraries++;
 389       j++;
 390     }
 391
 392   if (saw_math)
 393     new_decoded_options[j++] = *saw_math;
 394   else if (library > 0 && need_math)
 395     {
 396       generate_option (OPT_l,
 397                        saw_profile_flag ? MATH_LIBRARY_PROFILE : MATH_LIBRARY,
 398                        1, CL_DRIVER, &new_decoded_options[j]);
 399       added_libraries++;
 400       j++;
 401     }
 402
 403   if (saw_libc)
 404     new_decoded_options[j++] = *saw_libc;
 405   if (shared_libgcc && !static_link)
 406     generate_option (OPT_shared_libgcc, NULL, 1, CL_DRIVER,
 407                      &new_decoded_options[j++]);
 408
 409   /* libgcc wraps pthread_create to support split stack, however, due to
 410      relative ordering of -lpthread and -lgcc, we can't just mark
 411      __real_pthread_create in libgcc as non-weak.  But we need to link in
 412      pthread_create from pthread if we are statically linking, so we work-
 413      around by passing -u pthread_create to the linker. */
 414   if (static_link && supports_split_stack)
 415     {
 416       generate_option (OPT_Wl_, "-u,pthread_create", 1, CL_DRIVER,
 417                        &new_decoded_options[j]);
 418       j++;
 419     }
 420
 421 #if defined(TARGET_SOLARIS) && !defined(USE_GLD)
 422   /* We use a common symbol for go$zerovalue.  On Solaris, when not
 423      using the GNU linker, the Solaris linker needs an option to not
 424      warn about this.  Everything works without this option, but you
 425      get unsightly warnings at link time.  */
 426   generate_option (OPT_Wl_, "-t", 1, CL_DRIVER, &new_decoded_options[j]);
 427   j++;
 428 #endif
 429
 430   *in_decoded_options_count = j;
 431   *in_decoded_options = new_decoded_options;
 432   *in_added_libraries = added_libraries;
 433 }
 434
 435 /* Called before linking.  Returns 0 on success and -1 on failure.  */
 436 int lang_specific_pre_link (void)  /* Not used for Go.  */
 437 {
 438   return 0;
 439 }
 440
 441 /* Number of extra output files that lang_specific_pre_link may generate.  */
 442 int lang_specific_extra_outfiles = 0;  /* Not used for Go.  */