gcc/go/gospec.c

   1 /* gospec.c -- Specific flags and argument handling of the gcc Go front end.
   2    Copyright (C) 2009-2021 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_gstabs:
 219         case OPT_gstabs_:
 220         case OPT_gvms:
 221         case OPT_gxcoff:
 222         case OPT_gxcoff_:
 223           saw_opt_g = true;
 224           break;
 225
 226         case OPT_static:
 227           static_link = 1;
 228           break;
 229
 230         case OPT_static_libgcc:
 231           shared_libgcc = 0;
 232           break;
 233
 234         case OPT_static_libgo:
 235           library = library >= 0 ? 2 : library;
 236           args[i] |= SKIPOPT;
 237           break;
 238
 239         case OPT_SPECIAL_input_file:
 240           if (library == 0)
 241             library = 1;
 242
 243           if (first_go_file == NULL)
 244             {
 245               int len;
 246
 247               len = strlen (arg);
 248               if (len > 3 && strcmp (arg + len - 3, ".go") == 0)
 249                 first_go_file = arg;
 250             }
 251
 252           break;
 253         }
 254     }
 255
 256   /* There's no point adding -shared-libgcc if we don't have a shared
 257      libgcc.  */
 258 #ifndef ENABLE_SHARED_LIBGCC
 259   shared_libgcc = 0;
 260 #endif
 261
 262   /* Make sure to have room for the trailing NULL argument.  */
 263   num_args = argc + need_math + shared_libgcc + (library > 0) * 5 + 10;
 264   new_decoded_options = XNEWVEC (struct cl_decoded_option, num_args);
 265
 266   i = 0;
 267   j = 0;
 268
 269   /* Copy the 0th argument, i.e., the name of the program itself.  */
 270   new_decoded_options[j++] = decoded_options[i++];
 271
 272 #ifdef TARGET_CAN_SPLIT_STACK
 273   supports_split_stack = 1;
 274 #endif
 275
 276 #ifdef TARGET_CAN_SPLIT_STACK_64BIT
 277   if (is_m64)
 278     supports_split_stack = 1;
 279 #endif
 280
 281   /* If we are linking, pass -fsplit-stack if it is supported.  */
 282   if ((library >= 0) && supports_split_stack)
 283     {
 284       generate_option (OPT_fsplit_stack, NULL, 1, CL_DRIVER,
 285                        &new_decoded_options[j]);
 286       j++;
 287     }
 288
 289   /* The go1 compiler is going to enable debug info by default.  If we
 290      don't see any -g options, force -g, so that we invoke the
 291      assembler with the right debug option.  */
 292   if (!saw_opt_g)
 293     {
 294       generate_option (OPT_g, "1", 0, CL_DRIVER, &new_decoded_options[j]);
 295       j++;
 296     }
 297
 298   /* NOTE: We start at 1 now, not 0.  */
 299   while (i < argc)
 300     {
 301       new_decoded_options[j] = decoded_options[i];
 302
 303       /* Make sure -lgo is before the math library, since libgo itself
 304          uses those math routines.  */
 305       if (!saw_math && (args[i] & MATHLIB) && library > 0)
 306         {
 307           --j;
 308           saw_math = &decoded_options[i];
 309         }
 310
 311       if (!saw_thread && (args[i] & THREADLIB) && library > 0)
 312         {
 313           --j;
 314           saw_thread = &decoded_options[i];
 315         }
 316
 317       if (!saw_libc && (args[i] & WITHLIBC) && library > 0)
 318         {
 319           --j;
 320           saw_libc = &decoded_options[i];
 321         }
 322
 323       if ((args[i] & SKIPOPT) != 0)
 324         --j;
 325
 326       i++;
 327       j++;
 328     }
 329
 330   /* If we didn't see a -o option, add one.  This is because we need
 331      the driver to pass all .go files to go1.  Without a -o option the
 332      driver will invoke go1 separately for each input file.  FIXME:
 333      This should probably use some other interface to force the driver
 334      to set combine_inputs.  */
 335   if (first_go_file != NULL && !saw_opt_o)
 336     {
 337       if (saw_opt_c || saw_opt_S)
 338         {
 339           const char *base;
 340           int baselen;
 341           int alen;
 342           char *out;
 343
 344           base = lbasename (first_go_file);
 345           baselen = strlen (base) - 3;
 346           alen = baselen + 3;
 347           out = XNEWVEC (char, alen);
 348           memcpy (out, base, baselen);
 349           /* The driver will convert .o to some other suffix (e.g.,
 350              .obj) if appropriate.  */
 351           out[baselen] = '.';
 352           if (saw_opt_S)
 353             out[baselen + 1] = 's';
 354           else
 355             out[baselen + 1] = 'o';
 356           out[baselen + 2] = '\0';
 357           generate_option (OPT_o, out, 1, CL_DRIVER,
 358                            &new_decoded_options[j]);
 359         }
 360       else
 361         generate_option (OPT_o, "a.out", 1, CL_DRIVER,
 362                          &new_decoded_options[j]);
 363       j++;
 364     }
 365
 366   /* Add `-lgo' if we haven't already done so.  */
 367   if (library > 0)
 368     {
 369       generate_option (OPT_l, LIBGOBEGIN, 1, CL_DRIVER,
 370                        &new_decoded_options[j]);
 371       added_libraries++;
 372       j++;
 373
 374 #ifdef HAVE_LD_STATIC_DYNAMIC
 375       if (library > 1 && !static_link)
 376         {
 377           generate_option (OPT_Wl_, LD_STATIC_OPTION, 1, CL_DRIVER,
 378                            &new_decoded_options[j]);
 379           j++;
 380         }
 381 #endif
 382
 383       generate_option (OPT_l, saw_profile_flag ? LIBGO_PROFILE : LIBGO, 1,
 384                        CL_DRIVER, &new_decoded_options[j]);
 385       added_libraries++;
 386       j++;
 387
 388 #ifdef HAVE_LD_STATIC_DYNAMIC
 389       if (library > 1 && !static_link)
 390         {
 391           generate_option (OPT_Wl_, LD_DYNAMIC_OPTION, 1, CL_DRIVER,
 392                            &new_decoded_options[j]);
 393           j++;
 394         }
 395 #endif
 396
 397       /* When linking libgo statically we also need to link with the
 398          pthread library.  */
 399       if (library > 1 || static_link)
 400         need_thread = 1;
 401     }
 402
 403   if (saw_thread)
 404     new_decoded_options[j++] = *saw_thread;
 405   else if (library > 0 && need_thread)
 406     {
 407       generate_option (OPT_l,
 408                        (saw_profile_flag
 409                         ? THREAD_LIBRARY_PROFILE
 410                         : THREAD_LIBRARY),
 411                        1, CL_DRIVER, &new_decoded_options[j]);
 412       added_libraries++;
 413       j++;
 414     }
 415
 416   if (saw_math)
 417     new_decoded_options[j++] = *saw_math;
 418   else if (library > 0 && need_math)
 419     {
 420       generate_option (OPT_l,
 421                        saw_profile_flag ? MATH_LIBRARY_PROFILE : MATH_LIBRARY,
 422                        1, CL_DRIVER, &new_decoded_options[j]);
 423       added_libraries++;
 424       j++;
 425     }
 426
 427   if (saw_libc)
 428     new_decoded_options[j++] = *saw_libc;
 429   if (shared_libgcc && !static_link)
 430     generate_option (OPT_shared_libgcc, NULL, 1, CL_DRIVER,
 431                      &new_decoded_options[j++]);
 432
 433   /* libgcc wraps pthread_create to support split stack, however, due to
 434      relative ordering of -lpthread and -lgcc, we can't just mark
 435      __real_pthread_create in libgcc as non-weak.  But we need to link in
 436      pthread_create from pthread if we are statically linking, so we work-
 437      around by passing -u pthread_create to the linker. */
 438   if (static_link && supports_split_stack)
 439     {
 440       generate_option (OPT_Wl_, "-u,pthread_create", 1, CL_DRIVER,
 441                        &new_decoded_options[j]);
 442       j++;
 443     }
 444
 445 #if defined(TARGET_SOLARIS) && !defined(USE_GLD)
 446   /* We use a common symbol for go$zerovalue.  On Solaris, when not
 447      using the GNU linker, the Solaris linker needs an option to not
 448      warn about this.  Everything works without this option, but you
 449      get unsightly warnings at link time.  */
 450   generate_option (OPT_Wl_, "-t", 1, CL_DRIVER, &new_decoded_options[j]);
 451   j++;
 452 #endif
 453
 454   *in_decoded_options_count = j;
 455   *in_decoded_options = new_decoded_options;
 456   *in_added_libraries = added_libraries;
 457 }
 458
 459 /* Called before linking.  Returns 0 on success and -1 on failure.  */
 460 int lang_specific_pre_link (void)  /* Not used for Go.  */
 461 {
 462   return 0;
 463 }
 464
 465 /* Number of extra output files that lang_specific_pre_link may generate.  */
 466 int lang_specific_extra_outfiles = 0;  /* Not used for Go.  */