1 /* Definitions of target machine for GNU compiler, for HPs running 2 HPUX using the 64bit runtime model. 3 Copyright (C) 1999-2013 Free Software Foundation, Inc. 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3, or (at your option) 10 any later version. 11 12 GCC is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 /* We can debug dynamically linked executables on hpux11; we also 22 want dereferencing of a NULL pointer to cause a SEGV. Do not move 23 the "+Accept TypeMismatch" switch. We check for it in collect2 24 to determine which init/fini is needed. */ 25 #undef LINK_SPEC 26 #if ((TARGET_DEFAULT | TARGET_CPU_DEFAULT) & MASK_GNU_LD) 27 #define LINK_SPEC \ 28 "%{!shared:%{p:-L/lib/pa20_64/libp -L/usr/lib/pa20_64/libp %{!static:\ 29 %nwarning: consider linking with '-static' as system libraries with\n\ 30 %n profiling support are only provided in archive format}}}\ 31 %{!shared:%{pg:-L/lib/pa20_64/libp -L/usr/lib/pa20_64/libp %{!static:\ 32 %nwarning: consider linking with '-static' as system libraries with\n\ 33 %n profiling support are only provided in archive format}}}\ 34 %{!shared:%{!static:%{rdynamic:-E}}}\ 35 %{mhp-ld:+Accept TypeMismatch -z} %{mlinker-opt:-O}\ 36 %{!shared:-u main %{!nostdlib:%{!nodefaultlibs:-u __cxa_finalize}}}\ 37 %{static:-a archive} %{shared:%{mhp-ld:-b}%{!mhp-ld:-shared}}" 38 #else 39 #define LINK_SPEC \ 40 "%{!shared:%{p:-L/lib/pa20_64/libp -L/usr/lib/pa20_64/libp %{!static:\ 41 %nwarning: consider linking with '-static' as system libraries with\n\ 42 %n profiling support are only provided in archive format}}}\ 43 %{!shared:%{pg:-L/lib/pa20_64/libp -L/usr/lib/pa20_64/libp %{!static:\ 44 %nwarning: consider linking with '-static' as system libraries with\n\ 45 %n profiling support are only provided in archive format}}}\ 46 %{!shared:%{!static:%{rdynamic:-E}}}\ 47 %{!mgnu-ld:+Accept TypeMismatch -z} %{mlinker-opt:-O}\ 48 %{!shared:-u main %{!nostdlib:%{!nodefaultlibs:-u __cxa_finalize}}}\ 49 %{static:-a archive} %{shared:%{mgnu-ld:-shared}%{!mgnu-ld:-b}}" 50 #endif 51 52 /* Profiling support is only provided in libc.a. However, libprof and 53 libgprof are only available in shared form on HP-UX 11.00. We use 54 the shared form if we are using the GNU linker or an archive form 55 isn't available. We also usually need to link with libdld and it's 56 only available in shared form. */ 57 #undef LIB_SPEC 58 #if ((TARGET_DEFAULT | TARGET_CPU_DEFAULT) & MASK_GNU_LD) 59 #define LIB_SPEC \ 60 "%{!shared:\ 61 %{!p:%{!pg:%{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\ 62 %{mt|pthread:-lpthread} -lc\ 63 %{static:%{!nolibdld:-a shared -ldld -a archive -lc}\ 64 %{!mt:%{!pthread:-a shared -lc -a archive}}}}}\ 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 %{!mt:%{!pthread:-a shared -lc -a archive}}}}}\ 71 %{pg:%{static:%{!mhp-ld:-a shared}%{mhp-ld:-a archive_shared}}\ 72 -lgprof %{static:-a archive}\ 73 %{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\ 74 %{mt|pthread:-lpthread} -lc\ 75 %{static:%{!nolibdld:-a shared -ldld -a archive -lc}\ 76 %{!mt:%{!pthread:-a shared -lc -a archive}}}}}\ 77 %{shared:%{mt|pthread:-lpthread}}" 78 #else 79 #define LIB_SPEC \ 80 "%{!shared:\ 81 %{!p:%{!pg:%{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\ 82 %{mt|pthread:-lpthread} -lc\ 83 %{static:%{!nolibdld:-a shared -ldld -a archive -lc}\ 84 %{!mt:%{!pthread:-a shared -lc -a archive}}}}}\ 85 %{p:%{!pg:%{static:%{mgnu-ld:-a shared}%{!mgnu-ld:-a archive_shared}}\ 86 -lprof %{static:-a archive}\ 87 %{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\ 88 %{mt|pthread:-lpthread} -lc\ 89 %{static:%{!nolibdld:-a shared -ldld -a archive -lc}\ 90 %{!mt:%{!pthread:-a shared -lc -a archive}}}}}\ 91 %{pg:%{static:%{mgnu-ld:-a shared}%{!mgnu-ld:-a archive_shared}}\ 92 -lgprof %{static:-a archive}\ 93 %{fopenmp:%{static:-a shared} -lrt %{static:-a archive}}\ 94 %{mt|pthread:-lpthread} -lc\ 95 %{static:%{!nolibdld:-a shared -ldld -a archive -lc}\ 96 %{!mt:%{!pthread:-a shared -lc -a archive}}}}}\ 97 %{shared:%{mt|pthread:-lpthread}}" 98 #endif 99 100 /* The libgcc_stub.a and milli.a libraries need to come last. */ 101 #undef LINK_GCC_C_SEQUENCE_SPEC 102 #define LINK_GCC_C_SEQUENCE_SPEC "\ 103 %G %L %G %{!nostdlib:%{!nodefaultlibs:%{!shared:-lgcc_stub}\ 104 milli.a%s}}" 105 106 /* Under hpux11, the normal location of the `ld' and `as' programs is the 107 /usr/ccs/bin directory. */ 108 109 #ifndef CROSS_DIRECTORY_STRUCTURE 110 #undef MD_EXEC_PREFIX 111 #define MD_EXEC_PREFIX "/usr/ccs/bin" 112 #endif 113 114 /* Default prefixes. */ 115 116 #undef STANDARD_STARTFILE_PREFIX_1 117 #define STANDARD_STARTFILE_PREFIX_1 "/lib/pa20_64/" 118 119 #undef STANDARD_STARTFILE_PREFIX_2 120 #define STANDARD_STARTFILE_PREFIX_2 "/usr/lib/pa20_64/" 121 122 /* Under hpux11 the normal location of the various pa20_64 *crt*.o files 123 is the /usr/ccs/lib/pa20_64 directory. Some files may also be in the 124 /opt/langtools/lib/pa20_64 directory. */ 125 126 #ifndef CROSS_DIRECTORY_STRUCTURE 127 #undef MD_STARTFILE_PREFIX 128 #define MD_STARTFILE_PREFIX "/usr/ccs/lib/pa20_64/" 129 #endif 130 131 #ifndef CROSS_DIRECTORY_STRUCTURE 132 #undef MD_STARTFILE_PREFIX_1 133 #define MD_STARTFILE_PREFIX_1 "/opt/langtools/lib/pa20_64/" 134 #endif 135 136 /* This macro specifies the biggest alignment supported by the object 137 file format of this machine. 138 139 The .align directive in the HP assembler allows alignments up to 140 4096 bytes. However, the maximum alignment of a global common symbol 141 is 16 bytes using HP ld. Unfortunately, this macro doesn't provide 142 a method to check for common symbols. */ 143 #undef MAX_OFILE_ALIGNMENT 144 #define MAX_OFILE_ALIGNMENT 32768 145 146 /* Due to limitations in the target structure, it isn't currently possible 147 to dynamically switch between the GNU and HP assemblers. */ 148 #undef TARGET_GAS 149 150 /* Configure selects the standard ELFOS defines for use with GAS. */ 151 #ifdef USING_ELFOS_H 152 153 /* We are using GAS. */ 154 #define TARGET_GAS 1 155 156 #undef TARGET_ASM_FILE_START 157 #define TARGET_ASM_FILE_START pa_hpux64_gas_file_start 158 159 /* This is how we output a null terminated string. */ 160 #undef STRING_ASM_OP 161 #define STRING_ASM_OP "\t.stringz\t" 162 163 #define TEXT_SECTION_ASM_OP "\t.text" 164 #define DATA_SECTION_ASM_OP "\t.data" 165 #define BSS_SECTION_ASM_OP "\t.section\t.bss" 166 167 #define JCR_SECTION_NAME ".jcr" 168 169 #define HP_INIT_ARRAY_SECTION_ASM_OP "\t.section\t.init" 170 #define GNU_INIT_ARRAY_SECTION_ASM_OP "\t.section\t.init_array" 171 #define HP_FINI_ARRAY_SECTION_ASM_OP "\t.section\t.fini" 172 #define GNU_FINI_ARRAY_SECTION_ASM_OP "\t.section\t.fini_array" 173 174 /* We need to override the following two macros defined in elfos.h since 175 the .comm directive has a different syntax and it can't be used for 176 local common symbols. */ 177 #undef ASM_OUTPUT_ALIGNED_COMMON 178 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \ 179 pa_asm_output_aligned_common (FILE, NAME, SIZE, ALIGN) 180 181 #undef ASM_OUTPUT_ALIGNED_LOCAL 182 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN) \ 183 pa_asm_output_aligned_local (FILE, NAME, SIZE, ALIGN) 184 185 /* The define in pa.h doesn't work with the alias attribute. The 186 default is ok with the following define for GLOBAL_ASM_OP. */ 187 #undef TARGET_ASM_GLOBALIZE_LABEL 188 189 /* This is how we globalize a label. */ 190 #define GLOBAL_ASM_OP "\t.globl\t" 191 192 /* Hacked version from defaults.h that uses assemble_name_raw 193 instead of assemble_name. A symbol in a type directive that 194 isn't otherwise referenced doesn't cause the symbol to be 195 placed in the symbol table of the assembled object. */ 196 #undef ASM_OUTPUT_TYPE_DIRECTIVE 197 #define ASM_OUTPUT_TYPE_DIRECTIVE(STREAM, NAME, TYPE) \ 198 do { \ 199 fputs (TYPE_ASM_OP, STREAM); \ 200 assemble_name_raw (STREAM, NAME); \ 201 fputs (", ", STREAM); \ 202 fprintf (STREAM, TYPE_OPERAND_FMT, TYPE); \ 203 putc ('\n', STREAM); \ 204 } while (0) 205 206 /* Hacked version from elfos.h that doesn't output a label. */ 207 #undef ASM_DECLARE_FUNCTION_NAME 208 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \ 209 do { \ 210 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \ 211 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \ 212 } while (0) 213 214 /* The type of external references must be set correctly for the 215 dynamic loader to work correctly. This is equivalent to the 216 HP assembler's .IMPORT directive but relates more directly to 217 ELF object file types. */ 218 #undef ASM_OUTPUT_EXTERNAL 219 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \ 220 pa_hpux_asm_output_external ((FILE), (DECL), (NAME)) 221 #define ASM_OUTPUT_EXTERNAL_REAL(FILE, DECL, NAME) \ 222 do { \ 223 if (FUNCTION_NAME_P (NAME)) \ 224 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \ 225 else \ 226 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object"); \ 227 default_elf_asm_output_external (FILE, DECL, NAME); \ 228 } while (0) 229 230 /* We need set the type for external libcalls. Also note that not all 231 libcall names are passed to targetm.encode_section_info (e.g., __main). 232 Thus, we also have to do the section encoding if it hasn't been done 233 already. */ 234 #undef ASM_OUTPUT_EXTERNAL_LIBCALL 235 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \ 236 do { \ 237 if (!FUNCTION_NAME_P (XSTR (FUN, 0))) \ 238 pa_encode_label (FUN); \ 239 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, XSTR (FUN, 0), "function"); \ 240 } while (0) 241 242 /* We need to use the HP style for internal labels. */ 243 #undef ASM_GENERATE_INTERNAL_LABEL 244 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \ 245 sprintf (LABEL, "*%c$%s%04ld", (PREFIX)[0], (PREFIX) + 1, (long)(NUM)) 246 247 #else /* USING_ELFOS_H */ 248 249 /* We are not using GAS. */ 250 #define TARGET_GAS 0 251 252 /* HPUX 11 has the "new" HP assembler. It's still lousy, but it's a whole 253 lot better than the assembler shipped with older versions of hpux. 254 However, it doesn't support weak symbols and is a bad fit with ELF. */ 255 #undef NEW_HP_ASSEMBLER 256 #define NEW_HP_ASSEMBLER 1 257 258 /* It looks like DWARF2 will be the easiest debug format to handle on this 259 platform. */ 260 #define DWARF2_DEBUGGING_INFO 1 261 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG 262 263 /* This target uses the ELF object file format. */ 264 #define OBJECT_FORMAT_ELF 265 266 #undef TARGET_ASM_FILE_START 267 #define TARGET_ASM_FILE_START pa_hpux64_hpas_file_start 268 269 #undef TEXT_SECTION_ASM_OP 270 #define TEXT_SECTION_ASM_OP "\t.SUBSPA $CODE$\n" 271 #undef READONLY_DATA_SECTION_ASM_OP 272 #define READONLY_DATA_SECTION_ASM_OP "\t.SUBSPA $LIT$\n" 273 #undef DATA_SECTION_ASM_OP 274 #define DATA_SECTION_ASM_OP "\t.SUBSPA $DATA$\n" 275 #undef BSS_SECTION_ASM_OP 276 #define BSS_SECTION_ASM_OP "\t.SUBSPA $BSS$\n" 277 278 /* We provide explicit defines for CTORS_SECTION_ASM_OP and 279 DTORS_SECTION_ASM_OP since we don't yet have support for 280 named sections with the HP assembler. */ 281 #undef CTORS_SECTION_ASM_OP 282 #define CTORS_SECTION_ASM_OP "\t.SUBSPA \\.ctors,QUAD=1,ALIGN=8,ACCESS=31" 283 #undef DTORS_SECTION_ASM_OP 284 #define DTORS_SECTION_ASM_OP "\t.SUBSPA \\.dtors,QUAD=1,ALIGN=8,ACCESS=31" 285 286 #define HP_INIT_ARRAY_SECTION_ASM_OP \ 287 "\t.SUBSPA \\.init,QUAD=1,ALIGN=8,ACCESS=31" 288 #define GNU_INIT_ARRAY_SECTION_ASM_OP \ 289 "\t.SUBSPA \\.init_array,QUAD=1,ALIGN=8,ACCESS=31" 290 #define HP_FINI_ARRAY_SECTION_ASM_OP \ 291 "\t.SUBSPA \\.fini,QUAD=1,ALIGN=8,ACCESS=31" 292 #define GNU_FINI_ARRAY_SECTION_ASM_OP \ 293 "\t.SUBSPA \\.fini_array,QUAD=1,ALIGN=8,ACCESS=31" 294 295 #endif /* USING_ELFOS_H */ 296 297 /* The following defines, used to run constructors and destructors with 298 the SOM linker under HP-UX 11, are not needed. */ 299 #undef HAS_INIT_SECTION 300 #undef LD_INIT_SWITCH 301 #undef LD_FINI_SWITCH 302 303 /* The following STARTFILE_SPEC and ENDFILE_SPEC defines provide the 304 magic needed to run initializers and finalizers. */ 305 #undef STARTFILE_SPEC 306 #if TARGET_HPUX_11_31 307 #define STARTFILE_SPEC \ 308 "%{!shared: %{!symbolic: crt0%O%s} \ 309 %{munix=95:unix95.o%s} %{munix=98:unix98.o%s} \ 310 %{!munix=93:%{!munix=95:%{!munix=98:unix2003%O%s}}}} \ 311 %{static:crtbeginT%O%s} \ 312 %{!static:%{!shared:crtbegin%O%s} %{shared:crtbeginS%O%s}}" 313 #elif TARGET_HPUX_11_11 314 #define STARTFILE_SPEC \ 315 "%{!shared: %{!symbolic: crt0%O%s} %{munix=95:unix95.o%s} \ 316 %{!munix=93:%{!munix=95:unix98%O%s}}} %{static:crtbeginT%O%s} \ 317 %{!static:%{!shared:crtbegin%O%s} %{shared:crtbeginS%O%s}}" 318 #else 319 #define STARTFILE_SPEC \ 320 "%{!shared: %{!symbolic: crt0%O%s} %{munix=95:unix95%O%s}} \ 321 %{static:crtbeginT%O%s} %{!static:%{!shared:crtbegin%O%s} \ 322 %{shared:crtbeginS%O%s}}" 323 #endif 324 #undef ENDFILE_SPEC 325 #define ENDFILE_SPEC "%{!shared:crtend%O%s} %{shared:crtendS%O%s}" 326 327 /* Since HP uses the .init and .fini sections for array initializers 328 and finalizers, we need different defines for INIT_SECTION_ASM_OP 329 and FINI_SECTION_ASM_OP. With the implementation adopted below, 330 the sections are not actually used. However, we still must provide 331 defines to select the proper code path. */ 332 #undef INIT_SECTION_ASM_OP 333 #define INIT_SECTION_ASM_OP 334 #undef FINI_SECTION_ASM_OP 335 #define FINI_SECTION_ASM_OP 336 337 /* We are using array initializers and don't want calls in the INIT 338 and FINI sections. */ 339 #undef CRT_CALL_STATIC_FUNCTION 340 #define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC) 341 342 /* The init_priority attribute is not supported with HP ld. This could be 343 supported if collect2 was used with LD_INIT_SWITCH. Unfortunately, this 344 approach doesn't work with GNU ld since HP-UX doesn't support DT_INIT, 345 and therefore the -init and -fini GNU ld switches. */ 346 #undef SUPPORTS_INIT_PRIORITY 347 #define SUPPORTS_INIT_PRIORITY (TARGET_GNU_LD ? 1 : 0) 348 349 /* We use DTOR_LIST_BEGIN to carry a bunch of hacks to allow us to use 350 the init and fini array sections with both the HP and GNU linkers. 351 The linkers setup the required dynamic entries in the dynamic segment 352 and the dynamic linker does the calls. This approach avoids using 353 collect2. 354 355 The first hack is to implement __do_global_ctors_aux in crtbegin as 356 it needs to be the first entry in the init array so that it is called 357 last. HP got the order of the init array backwards. The DT_INIT_ARRAY 358 is supposed to be executed in the same order as the addresses appear in 359 the array. DT_FINI_ARRAY is supposed to be executed in the opposite 360 order. 361 362 The second hack is a set of plabels to implement the effect of 363 CRT_CALL_STATIC_FUNCTION. HP-UX 11 only supports DI_INIT_ARRAY and 364 DT_FINI_ARRAY and they put the arrays in .init and .fini, rather than 365 in .init_array and .fini_array. The standard defines for .init and 366 .fini have the execute flag set. So, the assembler has to be hacked 367 to munge the standard flags for these sections to make them agree 368 with what the HP linker expects. With the GNU linker, we need to 369 used the .init_array and .fini_array sections. So, we set up for 370 both just in case. Once we have built the table, the linker does 371 the rest of the work. 372 373 The order is significant. Placing __do_global_ctors_aux first in 374 the list, results in it being called last. User specified initializers, 375 either using the linker +init command or a plabel, run before the 376 initializers specified here. */ 377 378 /* We need to add frame_dummy to the initializer list if EH_FRAME_SECTION_NAME 379 or JCR_SECTION_NAME is defined. */ 380 #if defined(EH_FRAME_SECTION_NAME) || defined(JCR_SECTION_NAME) 381 #define PA_INIT_FRAME_DUMMY_ASM_OP ".dword P%frame_dummy" 382 #else 383 #define PA_INIT_FRAME_DUMMY_ASM_OP "" 384 #endif 385 386 /* The following hack sets up the .init, .init_array, .fini and 387 .fini_array sections. */ 388 #define PA_CRTBEGIN_HACK \ 389 asm (TEXT_SECTION_ASM_OP); \ 390 static void __attribute__((used)) \ 391 __do_global_ctors_aux (void) \ 392 { \ 393 func_ptr *p = __CTOR_LIST__; \ 394 while (*(p + 1)) \ 395 p++; \ 396 for (; *p != (func_ptr) -1; p--) \ 397 (*p) (); \ 398 } \ 399 \ 400 asm (HP_INIT_ARRAY_SECTION_ASM_OP); \ 401 asm (".align 8"); \ 402 asm (".dword P%__do_global_ctors_aux"); \ 403 asm (PA_INIT_FRAME_DUMMY_ASM_OP); \ 404 asm (GNU_INIT_ARRAY_SECTION_ASM_OP); \ 405 asm (".align 8"); \ 406 asm (".dword P%__do_global_ctors_aux"); \ 407 asm (PA_INIT_FRAME_DUMMY_ASM_OP); \ 408 asm (HP_FINI_ARRAY_SECTION_ASM_OP); \ 409 asm (".align 8"); \ 410 asm (".dword P%__do_global_dtors_aux"); \ 411 asm (GNU_FINI_ARRAY_SECTION_ASM_OP); \ 412 asm (".align 8"); \ 413 asm (".dword P%__do_global_dtors_aux") 414 415 /* The following two variants of DTOR_LIST_BEGIN are identical to those 416 in crtstuff.c except for the addition of the above crtbegin hack. */ 417 #ifdef DTORS_SECTION_ASM_OP 418 #define DTOR_LIST_BEGIN \ 419 asm (DTORS_SECTION_ASM_OP); \ 420 STATIC func_ptr __DTOR_LIST__[1] \ 421 __attribute__ ((aligned(sizeof(func_ptr)))) \ 422 = { (func_ptr) (-1) }; \ 423 PA_CRTBEGIN_HACK 424 #else 425 #define DTOR_LIST_BEGIN \ 426 STATIC func_ptr __DTOR_LIST__[1] \ 427 __attribute__ ((section(".dtors"), aligned(sizeof(func_ptr)))) \ 428 = { (func_ptr) (-1) }; \ 429 PA_CRTBEGIN_HACK 430 #endif 431 432 /* If using HP ld do not call pxdb. Use size as a program that does nothing 433 and returns 0. /bin/true cannot be used because it is a script without 434 an interpreter. */ 435 #define INIT_ENVIRONMENT "LD_PXDB=/usr/ccs/bin/size" 436 437 /* The HPUX dynamic linker objects to undefined weak symbols, so do 438 not use them in gthr-posix.h. */ 439 #define GTHREAD_USE_WEAK 0 440 441 /* We don't want undefined weak references to __register_frame_info, 442 __deregister_frame_info, _Jv_RegisterClasses and __cxa_finalize 443 introduced by crtbegin.o. The GNU linker only resolves weak 444 references if they appear in a shared library. Thus, it would be 445 impossible to create a static executable if the symbols were weak. 446 So, the best solution seems to be to make the symbols strong and 447 provide an archive library of empty stub functions. */ 448 #define TARGET_ATTRIBUTE_WEAK 449