gcc/config/pa/pa64-hpux.h

   1 /* Definitions of target machine for GNU compiler, for HPs running
   2    HPUX using the 64bit runtime model.
   3    Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2007, 2008
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 /* We can debug dynamically linked executables on hpux11; we also
  23    want dereferencing of a NULL pointer to cause a SEGV.  Do not move
  24    the "+Accept TypeMismatch" switch.  We check for it in collect2
  25    to determine which init/fini is needed.  */
  26 #undef LINK_SPEC
  27 #if ((TARGET_DEFAULT | TARGET_CPU_DEFAULT) & MASK_GNU_LD)
  28 #define LINK_SPEC \
  29   "%{!shared:%{p:-L/lib/pa20_64/libp -L/usr/lib/pa20_64/libp %{!static:\
  30      %nwarning: consider linking with '-static' as system libraries with\n\
  31      %n  profiling support are only provided in archive format}}}\
  32    %{!shared:%{pg:-L/lib/pa20_64/libp -L/usr/lib/pa20_64/libp %{!static:\
  33      %nwarning: consider linking with '-static' as system libraries with\n\
  34      %n  profiling support are only provided in archive format}}}\
  35    %{!shared:%{!static:%{rdynamic:-E}}}\
  36    %{mhp-ld:+Accept TypeMismatch -z} %{mlinker-opt:-O}\
  37    %{!shared:-u main %{!nostdlib:%{!nodefaultlibs:-u __cxa_finalize}}}\
  38    %{static:-a archive} %{shared:%{mhp-ld:-b}%{!mhp-ld:-shared}}"
  39 #else
  40 #define LINK_SPEC \
  41   "%{!shared:%{p:-L/lib/pa20_64/libp -L/usr/lib/pa20_64/libp %{!static:\
  42      %nwarning: consider linking with '-static' as system libraries with\n\
  43      %n  profiling support are only provided in archive format}}}\
  44    %{!shared:%{pg:-L/lib/pa20_64/libp -L/usr/lib/pa20_64/libp %{!static:\
  45      %nwarning: consider linking with '-static' as system libraries with\n\
  46      %n  profiling support are only provided in archive format}}}\
  47    %{!shared:%{!static:%{rdynamic:-E}}}\
  48    %{!mgnu-ld:+Accept TypeMismatch -z} %{mlinker-opt:-O}\
  49    %{!shared:-u main %{!nostdlib:%{!nodefaultlibs:-u __cxa_finalize}}}\
  50    %{static:-a archive} %{shared:%{mgnu-ld:-shared}%{!mgnu-ld:-b}}"
  51 #endif
  52
  53 /* Profiling support is only provided in libc.a.  However, libprof and
  54    libgprof are only available in shared form on HP-UX 11.00.  We use
  55    the shared form if we are using the GNU linker or an archive form
  56    isn't available.  We also usually need to link with libdld and it's
  57    only available in shared form.  */
  58 #undef LIB_SPEC
  59 #if ((TARGET_DEFAULT | TARGET_CPU_DEFAULT) & MASK_GNU_LD)
  60 #define LIB_SPEC \
  61   "%{!shared:\
  62      %{!p:%{!pg:%{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\
  63             %{mt|pthread:-lpthread} -lc\
  64             %{static:%{!nolibdld:-a shared -ldld -a archive -lc}}}}\
  65      %{p:%{!pg:%{static:%{!mhp-ld:-a shared}%{mhp-ld:-a archive_shared}}\
  66            -lprof %{static:-a archive}\
  67            %{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\
  68            %{mt|pthread:-lpthread} -lc\
  69            %{static:%{!nolibdld:-a shared -ldld -a archive -lc}}}}\
  70      %{pg:%{static:%{!mhp-ld:-a shared}%{mhp-ld:-a archive_shared}}\
  71        -lgprof %{static:-a archive}\
  72        %{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\
  73        %{mt|pthread:-lpthread} -lc\
  74        %{static:%{!nolibdld:-a shared -ldld -a archive -lc}}}}\
  75    %{shared:%{mt|pthread:-lpthread}}"
  76 #else
  77 #define LIB_SPEC \
  78   "%{!shared:\
  79      %{!p:%{!pg:%{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\
  80             %{mt|pthread:-lpthread} -lc\
  81             %{static:%{!nolibdld:-a shared -ldld -a archive -lc}}}}\
  82      %{p:%{!pg:%{static:%{mgnu-ld:-a shared}%{!mgnu-ld:-a archive_shared}}\
  83            -lprof %{static:-a archive}\
  84            %{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\
  85            %{mt|pthread:-lpthread} -lc\
  86            %{static:%{!nolibdld:-a shared -ldld -a archive -lc}}}}\
  87      %{pg:%{static:%{mgnu-ld:-a shared}%{!mgnu-ld:-a archive_shared}}\
  88        -lgprof %{static:-a archive}\
  89        %{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\
  90        %{mt|pthread:-lpthread} -lc\
  91        %{static:%{!nolibdld:-a shared -ldld -a archive -lc}}}}\
  92    %{shared:%{mt|pthread:-lpthread}}"
  93 #endif
  94
  95 /* The libgcc_stub.a and milli.a libraries need to come last.  */
  96 #undef LINK_GCC_C_SEQUENCE_SPEC
  97 #define LINK_GCC_C_SEQUENCE_SPEC "\
  98   %G %L %G %{!nostdlib:%{!nodefaultlibs:%{!shared:-lgcc_stub}\
  99   milli.a%s}}"
 100
 101 /* Under hpux11, the normal location of the `ld' and `as' programs is the
 102    /usr/ccs/bin directory.  */
 103
 104 #ifndef CROSS_DIRECTORY_STRUCTURE
 105 #undef MD_EXEC_PREFIX
 106 #define MD_EXEC_PREFIX "/usr/ccs/bin"
 107 #endif
 108
 109 /* Default prefixes.  */
 110
 111 #undef STANDARD_STARTFILE_PREFIX_1
 112 #define STANDARD_STARTFILE_PREFIX_1 "/lib/pa20_64/"
 113
 114 #undef STANDARD_STARTFILE_PREFIX_2
 115 #define STANDARD_STARTFILE_PREFIX_2 "/usr/lib/pa20_64/"
 116
 117 /* Under hpux11 the normal location of the various pa20_64 *crt*.o files
 118    is the /usr/ccs/lib/pa20_64 directory.  Some files may also be in the
 119    /opt/langtools/lib/pa20_64 directory.  */
 120
 121 #ifndef CROSS_DIRECTORY_STRUCTURE
 122 #undef MD_STARTFILE_PREFIX
 123 #define MD_STARTFILE_PREFIX "/usr/ccs/lib/pa20_64/"
 124 #endif
 125
 126 #ifndef CROSS_DIRECTORY_STRUCTURE
 127 #undef MD_STARTFILE_PREFIX_1
 128 #define MD_STARTFILE_PREFIX_1 "/opt/langtools/lib/pa20_64/"
 129 #endif
 130
 131 /* This macro specifies the biggest alignment supported by the object
 132    file format of this machine.
 133
 134    The .align directive in the HP assembler allows alignments up to
 135    4096 bytes.  However, the maximum alignment of a global common symbol
 136    is 16 bytes using HP ld.  Unfortunately, this macro doesn't provide
 137    a method to check for common symbols.  */
 138 #undef MAX_OFILE_ALIGNMENT
 139 #define MAX_OFILE_ALIGNMENT 32768
 140
 141 /* Due to limitations in the target structure, it isn't currently possible
 142    to dynamically switch between the GNU and HP assemblers.  */
 143 #undef TARGET_GAS
 144
 145 /* Configure selects the standard ELFOS defines for use with GAS.  */
 146 #ifdef USING_ELFOS_H
 147
 148 /* We are using GAS.  */
 149 #define TARGET_GAS 1
 150
 151 #undef TARGET_ASM_FILE_START
 152 #define TARGET_ASM_FILE_START pa_hpux64_gas_file_start
 153
 154 /* This is how we output a null terminated string.  */
 155 #undef STRING_ASM_OP
 156 #define STRING_ASM_OP   "\t.stringz\t"
 157
 158 #define TEXT_SECTION_ASM_OP     "\t.text"
 159 #define DATA_SECTION_ASM_OP     "\t.data"
 160 #define BSS_SECTION_ASM_OP      "\t.section\t.bss"
 161
 162 #define JCR_SECTION_NAME        ".jcr"
 163
 164 #define HP_INIT_ARRAY_SECTION_ASM_OP    "\t.section\t.init"
 165 #define GNU_INIT_ARRAY_SECTION_ASM_OP   "\t.section\t.init_array"
 166 #define HP_FINI_ARRAY_SECTION_ASM_OP    "\t.section\t.fini"
 167 #define GNU_FINI_ARRAY_SECTION_ASM_OP   "\t.section\t.fini_array"
 168
 169 /* We need to override the following two macros defined in elfos.h since
 170    the .comm directive has a different syntax and it can't be used for
 171    local common symbols.  */
 172 #undef ASM_OUTPUT_ALIGNED_COMMON
 173 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN)              \
 174   pa_asm_output_aligned_common (FILE, NAME, SIZE, ALIGN)
 175
 176 #undef ASM_OUTPUT_ALIGNED_LOCAL
 177 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN)               \
 178   pa_asm_output_aligned_local (FILE, NAME, SIZE, ALIGN)
 179
 180 /* The define in pa.h doesn't work with the alias attribute.  The
 181    default is ok with the following define for GLOBAL_ASM_OP.  */
 182 #undef TARGET_ASM_GLOBALIZE_LABEL
 183
 184 /* This is how we globalize a label.  */
 185 #define GLOBAL_ASM_OP   "\t.globl\t"
 186
 187 /* Hacked version from defaults.h that uses assemble_name_raw
 188    instead of assemble_name.  A symbol in a type directive that
 189    isn't otherwise referenced doesn't cause the symbol to be
 190    placed in the symbol table of the assembled object.  */
 191 #undef ASM_OUTPUT_TYPE_DIRECTIVE
 192 #define ASM_OUTPUT_TYPE_DIRECTIVE(STREAM, NAME, TYPE)           \
 193 do {                                                            \
 194   fputs (TYPE_ASM_OP, STREAM);                                  \
 195   assemble_name_raw (STREAM, NAME);                             \
 196   fputs (", ", STREAM);                                         \
 197   fprintf (STREAM, TYPE_OPERAND_FMT, TYPE);                     \
 198   putc ('\n', STREAM);                                          \
 199 } while (0)
 200
 201 /* Hacked version from elfos.h that doesn't output a label.  */
 202 #undef ASM_DECLARE_FUNCTION_NAME
 203 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL)             \
 204 do {                                                            \
 205   ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function");           \
 206   ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));                \
 207 } while (0)
 208
 209 /* The type of external references must be set correctly for the
 210    dynamic loader to work correctly.  This is equivalent to the
 211    HP assembler's .IMPORT directive but relates more directly to
 212    ELF object file types.  */
 213 #undef ASM_OUTPUT_EXTERNAL
 214 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME)                   \
 215   pa_hpux_asm_output_external ((FILE), (DECL), (NAME))
 216 #define ASM_OUTPUT_EXTERNAL_REAL(FILE, DECL, NAME)              \
 217 do {                                                            \
 218   if (FUNCTION_NAME_P (NAME))                                   \
 219     ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function");         \
 220   else                                                          \
 221     ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");           \
 222   default_elf_asm_output_external (FILE, DECL, NAME);           \
 223 } while (0)
 224
 225 /* We need set the type for external libcalls.  Also note that not all
 226    libcall names are passed to targetm.encode_section_info (e.g., __main).
 227    Thus, we also have to do the section encoding if it hasn't been done
 228    already.  */
 229 #undef ASM_OUTPUT_EXTERNAL_LIBCALL
 230 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN)                  \
 231 do {                                                            \
 232   if (!FUNCTION_NAME_P (XSTR (FUN, 0)))                         \
 233     hppa_encode_label (FUN);                                    \
 234   ASM_OUTPUT_TYPE_DIRECTIVE (FILE, XSTR (FUN, 0), "function");  \
 235 } while (0)
 236
 237 /* We need to use the HP style for internal labels.  */
 238 #undef ASM_GENERATE_INTERNAL_LABEL
 239 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \
 240   sprintf (LABEL, "*%c$%s%04ld", (PREFIX)[0], (PREFIX) + 1, (long)(NUM))
 241
 242 #else /* USING_ELFOS_H */
 243
 244 /* We are not using GAS.  */
 245 #define TARGET_GAS 0
 246
 247 /* HPUX 11 has the "new" HP assembler.  It's still lousy, but it's a whole
 248    lot better than the assembler shipped with older versions of hpux.
 249    However, it doesn't support weak symbols and is a bad fit with ELF.  */
 250 #undef NEW_HP_ASSEMBLER
 251 #define NEW_HP_ASSEMBLER 1
 252
 253 /* It looks like DWARF2 will be the easiest debug format to handle on this
 254    platform.  */
 255 #define DWARF2_DEBUGGING_INFO 1
 256 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
 257
 258 /* This target uses the ELF object file format.  */
 259 #define OBJECT_FORMAT_ELF
 260
 261 #undef TARGET_ASM_FILE_START
 262 #define TARGET_ASM_FILE_START pa_hpux64_hpas_file_start
 263
 264 #undef TEXT_SECTION_ASM_OP
 265 #define TEXT_SECTION_ASM_OP             "\t.SUBSPA $CODE$\n"
 266 #undef READONLY_DATA_SECTION_ASM_OP
 267 #define READONLY_DATA_SECTION_ASM_OP    "\t.SUBSPA $LIT$\n"
 268 #undef DATA_SECTION_ASM_OP
 269 #define DATA_SECTION_ASM_OP             "\t.SUBSPA $DATA$\n"
 270 #undef BSS_SECTION_ASM_OP
 271 #define BSS_SECTION_ASM_OP              "\t.SUBSPA $BSS$\n"
 272
 273 /* We provide explicit defines for CTORS_SECTION_ASM_OP and
 274    DTORS_SECTION_ASM_OP since we don't yet have support for
 275    named sections with the HP assembler.  */
 276 #undef CTORS_SECTION_ASM_OP
 277 #define CTORS_SECTION_ASM_OP "\t.SUBSPA \\.ctors,QUAD=1,ALIGN=8,ACCESS=31"
 278 #undef DTORS_SECTION_ASM_OP
 279 #define DTORS_SECTION_ASM_OP "\t.SUBSPA \\.dtors,QUAD=1,ALIGN=8,ACCESS=31"
 280
 281 #define HP_INIT_ARRAY_SECTION_ASM_OP \
 282   "\t.SUBSPA \\.init,QUAD=1,ALIGN=8,ACCESS=31"
 283 #define GNU_INIT_ARRAY_SECTION_ASM_OP \
 284   "\t.SUBSPA \\.init_array,QUAD=1,ALIGN=8,ACCESS=31"
 285 #define HP_FINI_ARRAY_SECTION_ASM_OP \
 286   "\t.SUBSPA \\.fini,QUAD=1,ALIGN=8,ACCESS=31"
 287 #define GNU_FINI_ARRAY_SECTION_ASM_OP \
 288   "\t.SUBSPA \\.fini_array,QUAD=1,ALIGN=8,ACCESS=31"
 289
 290 #endif /* USING_ELFOS_H */
 291
 292 /* The following defines, used to run constructors and destructors with
 293    the SOM linker under HP-UX 11, are not needed.  */
 294 #undef HAS_INIT_SECTION
 295 #undef LD_INIT_SWITCH
 296 #undef LD_FINI_SWITCH
 297
 298 /* The following STARTFILE_SPEC and ENDFILE_SPEC defines provide the
 299    magic needed to run initializers and finalizers.  */
 300 #undef STARTFILE_SPEC
 301 #if TARGET_HPUX_11_11
 302 #define STARTFILE_SPEC \
 303   "%{!shared: %{!symbolic: crt0%O%s} %{munix=95:unix95.o%s} \
 304      %{!munix=93:%{!munix=95:unix98%O%s}}} %{static:crtbeginT%O%s} \
 305    %{!static:%{!shared:crtbegin%O%s} %{shared:crtbeginS%O%s}}"
 306 #else
 307 #define STARTFILE_SPEC \
 308   "%{!shared: %{!symbolic: crt0%O%s} %{munix=95:unix95%O%s}} \
 309    %{static:crtbeginT%O%s} %{!static:%{!shared:crtbegin%O%s} \
 310    %{shared:crtbeginS%O%s}}"
 311 #endif
 312 #undef ENDFILE_SPEC
 313 #define ENDFILE_SPEC "%{!shared:crtend%O%s} %{shared:crtendS%O%s}"
 314
 315 /* Since HP uses the .init and .fini sections for array initializers
 316    and finalizers, we need different defines for INIT_SECTION_ASM_OP
 317    and FINI_SECTION_ASM_OP.  With the implementation adopted below,
 318    the sections are not actually used.  However, we still must provide
 319    defines to select the proper code path.  */
 320 #undef INIT_SECTION_ASM_OP
 321 #define INIT_SECTION_ASM_OP
 322 #undef FINI_SECTION_ASM_OP
 323 #define FINI_SECTION_ASM_OP
 324
 325 /* We are using array initializers and don't want calls in the INIT
 326    and FINI sections.  */
 327 #undef CRT_CALL_STATIC_FUNCTION
 328 #define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC)
 329
 330 /* The init_priority attribute is not supported with HP ld.  This could be
 331    supported if collect2 was used with LD_INIT_SWITCH.  Unfortunately, this
 332    approach doesn't work with GNU ld since HP-UX doesn't support DT_INIT,
 333    and therefore the -init and -fini GNU ld switches.  */
 334 #undef SUPPORTS_INIT_PRIORITY
 335 #define SUPPORTS_INIT_PRIORITY (TARGET_GNU_LD ? 1 : 0)
 336
 337 /* We use DTOR_LIST_BEGIN to carry a bunch of hacks to allow us to use
 338    the init and fini array sections with both the HP and GNU linkers.
 339    The linkers setup the required dynamic entries in the dynamic segment
 340    and the dynamic linker does the calls.  This approach avoids using
 341    collect2.
 342
 343    The first hack is to implement __do_global_ctors_aux in crtbegin as
 344    it needs to be the first entry in the init array so that it is called
 345    last.  HP got the order of the init array backwards.  The DT_INIT_ARRAY
 346    is supposed to be executed in the same order as the addresses appear in
 347    the array.  DT_FINI_ARRAY is supposed to be executed in the opposite
 348    order.
 349
 350    The second hack is a set of plabels to implement the effect of
 351    CRT_CALL_STATIC_FUNCTION.  HP-UX 11 only supports DI_INIT_ARRAY and
 352    DT_FINI_ARRAY and they put the arrays in .init and .fini, rather than
 353    in .init_array and .fini_array.  The standard defines for .init and
 354    .fini have the execute flag set.  So, the assembler has to be hacked
 355    to munge the standard flags for these sections to make them agree
 356    with what the HP linker expects.  With the GNU linker, we need to
 357    used the .init_array and .fini_array sections.  So, we set up for
 358    both just in case.  Once we have built the table, the linker does
 359    the rest of the work.
 360
 361    The order is significant.  Placing __do_global_ctors_aux first in
 362    the list, results in it being called last.  User specified initializers,
 363    either using the linker +init command or a plabel, run before the
 364    initializers specified here.  */
 365
 366 /* We need to add frame_dummy to the initializer list if EH_FRAME_SECTION_NAME
 367    or JCR_SECTION_NAME is defined.  */
 368 #if defined(EH_FRAME_SECTION_NAME) || defined(JCR_SECTION_NAME)
 369 #define PA_INIT_FRAME_DUMMY_ASM_OP ".dword P%frame_dummy"
 370 #else
 371 #define PA_INIT_FRAME_DUMMY_ASM_OP ""
 372 #endif
 373
 374 /* The following hack sets up the .init, .init_array, .fini and
 375    .fini_array sections.  */
 376 #define PA_CRTBEGIN_HACK \
 377 asm (TEXT_SECTION_ASM_OP);                                              \
 378 static void __attribute__((used))                                       \
 379 __do_global_ctors_aux (void)                                            \
 380 {                                                                       \
 381   func_ptr *p = __CTOR_LIST__;                                          \
 382   while (*(p + 1))                                                      \
 383     p++;                                                                \
 384   for (; *p != (func_ptr) -1; p--)                                      \
 385     (*p) ();                                                            \
 386 }                                                                       \
 387                                                                         \
 388 asm (HP_INIT_ARRAY_SECTION_ASM_OP);                                     \
 389 asm (".align 8");                                                       \
 390 asm (".dword P%__do_global_ctors_aux");                                 \
 391 asm (PA_INIT_FRAME_DUMMY_ASM_OP);                                       \
 392 asm (GNU_INIT_ARRAY_SECTION_ASM_OP);                                    \
 393 asm (".align 8");                                                       \
 394 asm (".dword P%__do_global_ctors_aux");                                 \
 395 asm (PA_INIT_FRAME_DUMMY_ASM_OP);                                       \
 396 asm (HP_FINI_ARRAY_SECTION_ASM_OP);                                     \
 397 asm (".align 8");                                                       \
 398 asm (".dword P%__do_global_dtors_aux");                                 \
 399 asm (GNU_FINI_ARRAY_SECTION_ASM_OP);                                    \
 400 asm (".align 8");                                                       \
 401 asm (".dword P%__do_global_dtors_aux")
 402
 403 /* The following two variants of DTOR_LIST_BEGIN are identical to those
 404    in crtstuff.c except for the addition of the above crtbegin hack.  */
 405 #ifdef DTORS_SECTION_ASM_OP
 406 #define DTOR_LIST_BEGIN \
 407 asm (DTORS_SECTION_ASM_OP);                                             \
 408 STATIC func_ptr __DTOR_LIST__[1]                                        \
 409   __attribute__ ((aligned(sizeof(func_ptr))))                           \
 410   = { (func_ptr) (-1) };                                                \
 411 PA_CRTBEGIN_HACK
 412 #else
 413 #define DTOR_LIST_BEGIN \
 414 STATIC func_ptr __DTOR_LIST__[1]                                        \
 415   __attribute__ ((section(".dtors"), aligned(sizeof(func_ptr))))        \
 416   = { (func_ptr) (-1) };                                                \
 417 PA_CRTBEGIN_HACK
 418 #endif
 419
 420 /* If using HP ld do not call pxdb.  Use size as a program that does nothing
 421    and returns 0.  /bin/true cannot be used because it is a script without
 422    an interpreter.  */
 423 #define INIT_ENVIRONMENT "LD_PXDB=/usr/ccs/bin/size"
 424
 425 /* The HPUX dynamic linker objects to undefined weak symbols, so do
 426    not use them in gthr-posix.h.  */
 427 #define GTHREAD_USE_WEAK 0
 428
 429 /* We don't want undefined weak references to __register_frame_info,
 430    __deregister_frame_info, _Jv_RegisterClasses and __cxa_finalize
 431    introduced by crtbegin.o.  The GNU linker only resolves weak
 432    references if they appear in a shared library.  Thus, it would be
 433    impossible to create a static executable if the symbols were weak.
 434    So, the best solution seems to be to make the symbols strong and
 435    provide an archive library of empty stub functions.  */
 436 #define TARGET_ATTRIBUTE_WEAK