gcc/go/gospec.c

   1 /* gospec.c -- Specific flags and argument handling of the gcc Go front end.
   2    Copyright (C) 2009-2014 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 "gcc.h"
  25 #include "opts.h"
  26
  27 /* This bit is set if we saw a `-xfoo' language specification.  */
  28 #define LANGSPEC        (1<<1)
  29 /* This bit is set if they did `-lm' or `-lmath'.  */
  30 #define MATHLIB         (1<<2)
  31 /* This bit is set if they did `-lpthread'.  */
  32 #define THREADLIB       (1<<3)
  33 /* This bit is set if they did `-lc'.  */
  34 #define WITHLIBC        (1<<4)
  35 /* Skip this option.  */
  36 #define SKIPOPT         (1<<5)
  37
  38 #ifndef MATH_LIBRARY
  39 #define MATH_LIBRARY "m"
  40 #endif
  41 #ifndef MATH_LIBRARY_PROFILE
  42 #define MATH_LIBRARY_PROFILE MATH_LIBRARY
  43 #endif
  44
  45 #define THREAD_LIBRARY "pthread"
  46 #define THREAD_LIBRARY_PROFILE THREAD_LIBRARY
  47
  48 #define LIBGO "go"
  49 #define LIBGO_PROFILE LIBGO
  50 #define LIBGOBEGIN "gobegin"
  51
  52 void
  53 lang_specific_driver (struct cl_decoded_option **in_decoded_options,
  54                       unsigned int *in_decoded_options_count,
  55                       int *in_added_libraries)
  56 {
  57   unsigned int i, j;
  58
  59   /* If true, the user gave us the `-p' or `-pg' flag.  */
  60   bool saw_profile_flag = false;
  61
  62   /* This is a tristate:
  63      -1 means we should not link in libgo
  64      0  means we should link in libgo if it is needed
  65      1  means libgo is needed and should be linked in.
  66      2  means libgo is needed and should be linked statically.  */
  67   int library = 0;
  68
  69   /* The new argument list will be contained in this.  */
  70   struct cl_decoded_option *new_decoded_options;
  71
  72   /* "-lm" or "-lmath" if it appears on the command line.  */
  73   const struct cl_decoded_option *saw_math = 0;
  74
  75   /* "-lpthread" if it appears on the command line.  */
  76   const struct cl_decoded_option *saw_thread = 0;
  77
  78   /* "-lc" if it appears on the command line.  */
  79   const struct cl_decoded_option *saw_libc = 0;
  80
  81   /* An array used to flag each argument that needs a bit set for
  82      LANGSPEC, MATHLIB, or WITHLIBC.  */
  83   int *args;
  84
  85   /* Whether we need the thread library.  */
  86   int need_thread = 0;
  87
  88   /* By default, we throw on the math library if we have one.  */
  89   int need_math = (MATH_LIBRARY[0] != '\0');
  90
  91   /* True if we saw -static.  */
  92   int static_link = 0;
  93
  94   /* True if we should add -shared-libgcc to the command-line.  */
  95   int shared_libgcc = 1;
  96
  97   /* The total number of arguments with the new stuff.  */
  98   unsigned int argc;
  99
 100   /* The argument list.  */
 101   struct cl_decoded_option *decoded_options;
 102
 103   /* The number of libraries added in.  */
 104   int added_libraries;
 105
 106   /* The total number of arguments with the new stuff.  */
 107   int num_args = 1;
 108
 109   /* Whether the -o option was used.  */
 110   bool saw_opt_o = false;
 111
 112   /* Whether the -c option was used.  Also used for -E, -fsyntax-only,
 113      in general anything which implies only compilation and not
 114      linking.  */
 115   bool saw_opt_c = false;
 116
 117   /* Whether the -S option was used.  */
 118   bool saw_opt_S = false;
 119
 120   /* The first input file with an extension of .go.  */
 121   const char *first_go_file = NULL;
 122
 123   argc = *in_decoded_options_count;
 124   decoded_options = *in_decoded_options;
 125   added_libraries = *in_added_libraries;
 126
 127   args = XCNEWVEC (int, argc);
 128
 129   for (i = 1; i < argc; i++)
 130     {
 131       const char *arg = decoded_options[i].arg;
 132
 133       switch (decoded_options[i].opt_index)
 134         {
 135         case OPT_nostdlib:
 136         case OPT_nodefaultlibs:
 137           library = -1;
 138           break;
 139
 140         case OPT_l:
 141           if (strcmp (arg, MATH_LIBRARY) == 0)
 142             {
 143               args[i] |= MATHLIB;
 144               need_math = 0;
 145             }
 146           else if (strcmp (arg, THREAD_LIBRARY) == 0)
 147             args[i] |= THREADLIB;
 148           else if (strcmp (arg, "c") == 0)
 149             args[i] |= WITHLIBC;
 150           else
 151             /* Unrecognized libraries (e.g. -lfoo) may require libgo.  */
 152             library = (library == 0) ? 1 : library;
 153           break;
 154
 155         case OPT_pg:
 156         case OPT_p:
 157           saw_profile_flag = true;
 158           break;
 159
 160         case OPT_x:
 161           if (library == 0 && strcmp (arg, "go") == 0)
 162             library = 1;
 163           break;
 164
 165         case OPT_Xlinker:
 166         case OPT_Wl_:
 167           /* Arguments that go directly to the linker might be .o files,
 168              or something, and so might cause libgo to be needed.  */
 169           if (library == 0)
 170             library = 1;
 171           break;
 172
 173         case OPT_c:
 174         case OPT_E:
 175         case OPT_M:
 176         case OPT_MM:
 177         case OPT_fsyntax_only:
 178           /* Don't specify libraries if we won't link, since that would
 179              cause a warning.  */
 180           saw_opt_c = true;
 181           library = -1;
 182           break;
 183
 184         case OPT_S:
 185           saw_opt_S = true;
 186           library = -1;
 187           break;
 188
 189         case OPT_o:
 190           saw_opt_o = true;
 191           break;
 192
 193         case OPT_static:
 194           static_link = 1;
 195           break;
 196
 197         case OPT_static_libgcc:
 198           shared_libgcc = 0;
 199           break;
 200
 201         case OPT_static_libgo:
 202           library = library >= 0 ? 2 : library;
 203           args[i] |= SKIPOPT;
 204           break;
 205
 206         case OPT_SPECIAL_input_file:
 207           if (library == 0)
 208             library = 1;
 209
 210           if (first_go_file == NULL)
 211             {
 212               int len;
 213
 214               len = strlen (arg);
 215               if (len > 3 && strcmp (arg + len - 3, ".go") == 0)
 216                 first_go_file = arg;
 217             }
 218
 219           break;
 220         }
 221     }
 222
 223   /* There's no point adding -shared-libgcc if we don't have a shared
 224      libgcc.  */
 225 #ifndef ENABLE_SHARED_LIBGCC
 226   shared_libgcc = 0;
 227 #endif
 228
 229   /* Make sure to have room for the trailing NULL argument.  */
 230   num_args = argc + need_math + shared_libgcc + (library > 0) * 5 + 10;
 231   new_decoded_options = XNEWVEC (struct cl_decoded_option, num_args);
 232
 233   i = 0;
 234   j = 0;
 235
 236   /* Copy the 0th argument, i.e., the name of the program itself.  */
 237   new_decoded_options[j++] = decoded_options[i++];
 238
 239   /* If we are linking, pass -fsplit-stack if it is supported.  */
 240 #ifdef TARGET_CAN_SPLIT_STACK
 241   if (library >= 0)
 242     {
 243       generate_option (OPT_fsplit_stack, NULL, 1, CL_DRIVER,
 244                        &new_decoded_options[j]);
 245       j++;
 246     }
 247 #endif
 248
 249   /* NOTE: We start at 1 now, not 0.  */
 250   while (i < argc)
 251     {
 252       new_decoded_options[j] = decoded_options[i];
 253
 254       /* Make sure -lgo is before the math library, since libgo itself
 255          uses those math routines.  */
 256       if (!saw_math && (args[i] & MATHLIB) && library > 0)
 257         {
 258           --j;
 259           saw_math = &decoded_options[i];
 260         }
 261
 262       if (!saw_thread && (args[i] & THREADLIB) && library > 0)
 263         {
 264           --j;
 265           saw_thread = &decoded_options[i];
 266         }
 267
 268       if (!saw_libc && (args[i] & WITHLIBC) && library > 0)
 269         {
 270           --j;
 271           saw_libc = &decoded_options[i];
 272         }
 273
 274       if ((args[i] & SKIPOPT) != 0)
 275         --j;
 276
 277       i++;
 278       j++;
 279     }
 280
 281   /* If we didn't see a -o option, add one.  This is because we need
 282      the driver to pass all .go files to go1.  Without a -o option the
 283      driver will invoke go1 separately for each input file.  FIXME:
 284      This should probably use some other interface to force the driver
 285      to set combine_inputs.  */
 286   if (first_go_file != NULL && !saw_opt_o)
 287     {
 288       if (saw_opt_c || saw_opt_S)
 289         {
 290           const char *base;
 291           int baselen;
 292           int alen;
 293           char *out;
 294
 295           base = lbasename (first_go_file);
 296           baselen = strlen (base) - 3;
 297           alen = baselen + 3;
 298           out = XNEWVEC (char, alen);
 299           memcpy (out, base, baselen);
 300           /* The driver will convert .o to some other suffix (e.g.,
 301              .obj) if appropriate.  */
 302           out[baselen] = '.';
 303           if (saw_opt_S)
 304             out[baselen + 1] = 's';
 305           else
 306             out[baselen + 1] = 'o';
 307           out[baselen + 2] = '\0';
 308           generate_option (OPT_o, out, 1, CL_DRIVER,
 309                            &new_decoded_options[j]);
 310         }
 311       else
 312         generate_option (OPT_o, "a.out", 1, CL_DRIVER,
 313                          &new_decoded_options[j]);
 314       j++;
 315     }
 316
 317   /* Add `-lgo' if we haven't already done so.  */
 318   if (library > 0)
 319     {
 320       generate_option (OPT_l, LIBGOBEGIN, 1, CL_DRIVER,
 321                        &new_decoded_options[j]);
 322       added_libraries++;
 323       j++;
 324
 325 #ifdef HAVE_LD_STATIC_DYNAMIC
 326       if (library > 1 && !static_link)
 327         {
 328           generate_option (OPT_Wl_, LD_STATIC_OPTION, 1, CL_DRIVER,
 329                            &new_decoded_options[j]);
 330           j++;
 331         }
 332 #endif
 333
 334       generate_option (OPT_l, saw_profile_flag ? LIBGO_PROFILE : LIBGO, 1,
 335                        CL_DRIVER, &new_decoded_options[j]);
 336       added_libraries++;
 337       j++;
 338
 339 #ifdef HAVE_LD_STATIC_DYNAMIC
 340       if (library > 1 && !static_link)
 341         {
 342           generate_option (OPT_Wl_, LD_DYNAMIC_OPTION, 1, CL_DRIVER,
 343                            &new_decoded_options[j]);
 344           j++;
 345         }
 346 #endif
 347
 348       /* When linking libgo statically we also need to link with the
 349          pthread library.  */
 350       if (library > 1 || static_link)
 351         need_thread = 1;
 352     }
 353
 354   if (saw_thread)
 355     new_decoded_options[j++] = *saw_thread;
 356   else if (library > 0 && need_thread)
 357     {
 358       generate_option (OPT_l,
 359                        (saw_profile_flag
 360                         ? THREAD_LIBRARY_PROFILE
 361                         : THREAD_LIBRARY),
 362                        1, CL_DRIVER, &new_decoded_options[j]);
 363       added_libraries++;
 364       j++;
 365     }
 366
 367   if (saw_math)
 368     new_decoded_options[j++] = *saw_math;
 369   else if (library > 0 && need_math)
 370     {
 371       generate_option (OPT_l,
 372                        saw_profile_flag ? MATH_LIBRARY_PROFILE : MATH_LIBRARY,
 373                        1, CL_DRIVER, &new_decoded_options[j]);
 374       added_libraries++;
 375       j++;
 376     }
 377
 378   if (saw_libc)
 379     new_decoded_options[j++] = *saw_libc;
 380   if (shared_libgcc && !static_link)
 381     generate_option (OPT_shared_libgcc, NULL, 1, CL_DRIVER,
 382                      &new_decoded_options[j++]);
 383
 384 #ifdef TARGET_CAN_SPLIT_STACK
 385   /* libgcc wraps pthread_create to support split stack, however, due to
 386      relative ordering of -lpthread and -lgcc, we can't just mark
 387      __real_pthread_create in libgcc as non-weak.  But we need to link in
 388      pthread_create from pthread if we are statically linking, so we work-
 389      around by passing -u pthread_create to to the linker. */
 390   if (static_link)
 391     {
 392       generate_option (OPT_Wl_, "-u,pthread_create", 1, CL_DRIVER,
 393                        &new_decoded_options[j]);
 394       j++;
 395     }
 396 #endif
 397
 398 #if defined(TARGET_SOLARIS) && !defined(USE_GLD)
 399   /* We use a common symbol for go$zerovalue.  On Solaris, when not
 400      using the GNU linker, the Solaris linker needs an option to not
 401      warn about this.  Everything works without this option, but you
 402      get unsightly warnings at link time.  */
 403   generate_option (OPT_Wl_, "-t", 1, CL_DRIVER, &new_decoded_options[j]);
 404   j++;
 405 #endif
 406
 407   *in_decoded_options_count = j;
 408   *in_decoded_options = new_decoded_options;
 409   *in_added_libraries = added_libraries;
 410 }
 411
 412 /* Called before linking.  Returns 0 on success and -1 on failure.  */
 413 int lang_specific_pre_link (void)  /* Not used for Go.  */
 414 {
 415   return 0;
 416 }
 417
 418 /* Number of extra output files that lang_specific_pre_link may generate.  */
 419 int lang_specific_extra_outfiles = 0;  /* Not used for Go.  */