1 /* elfos.h -- operating system specific defines to be used when 2 targeting GCC for some generic ELF system 3 Copyright (C) 1991, 1994, 1995, 1999, 2000, 2001, 2002, 2003, 2004, 4 2007, 2009, 2010 Free Software Foundation, Inc. 5 Based on svr4.h contributed by Ron Guilmette (rfg (at) netcom.com). 6 7 This file is part of GCC. 8 9 GCC is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 3, or (at your option) 12 any later version. 13 14 GCC is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 Under Section 7 of GPL version 3, you are granted additional 20 permissions described in the GCC Runtime Library Exception, version 21 3.1, as published by the Free Software Foundation. 22 23 You should have received a copy of the GNU General Public License and 24 a copy of the GCC Runtime Library Exception along with this program; 25 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 26 <http://www.gnu.org/licenses/>. */ 27 28 #define TARGET_OBJFMT_CPP_BUILTINS() \ 29 do \ 30 { \ 31 builtin_define ("__ELF__"); \ 32 } \ 33 while (0) 34 35 /* Define a symbol indicating that we are using elfos.h. 36 Some CPU specific configuration files use this. */ 37 #define USING_ELFOS_H 38 39 /* The prefix to add to user-visible assembler symbols. 40 41 For ELF systems the convention is *not* to prepend a leading 42 underscore onto user-level symbol names. */ 43 44 #undef USER_LABEL_PREFIX 45 #define USER_LABEL_PREFIX "" 46 47 /* The biggest alignment supported by ELF in bits. 32-bit ELF 48 supports section alignment up to (0x80000000 * 8), while 49 64-bit ELF supports (0x8000000000000000 * 8). If this macro 50 is not defined, the default is the largest alignment supported 51 by 32-bit ELF and representable on a 32-bit host. Use this 52 macro to limit the alignment which can be specified using 53 the `__attribute__ ((aligned (N)))' construct. */ 54 #ifndef MAX_OFILE_ALIGNMENT 55 #define MAX_OFILE_ALIGNMENT (((unsigned int) 1 << 28) * 8) 56 #endif 57 58 /* Use periods rather than dollar signs in special g++ assembler names. */ 59 60 #define NO_DOLLAR_IN_LABEL 61 62 /* Writing `int' for a bit-field forces int alignment for the structure. */ 63 64 #ifndef PCC_BITFIELD_TYPE_MATTERS 65 #define PCC_BITFIELD_TYPE_MATTERS 1 66 #endif 67 68 /* All ELF targets can support DWARF-2. */ 69 70 #define DWARF2_DEBUGGING_INFO 1 71 72 /* The GNU tools operate better with dwarf2, and it is required by some 73 psABI's. Since we don't have any native tools to be compatible with, 74 default to dwarf2. */ 75 76 #ifndef PREFERRED_DEBUGGING_TYPE 77 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG 78 #endif 79 80 /* All SVR4 targets use the ELF object file format. */ 81 #define OBJECT_FORMAT_ELF 82 83 84 /* Output #ident as a .ident. */ 85 86 #define ASM_OUTPUT_IDENT(FILE, NAME) \ 87 fprintf (FILE, "%s\"%s\"\n", IDENT_ASM_OP, NAME); 88 89 #define IDENT_ASM_OP "\t.ident\t" 90 91 #undef SET_ASM_OP 92 #define SET_ASM_OP "\t.set\t" 93 94 /* Most svr4 assemblers want a .file directive at the beginning of 95 their input file. */ 96 #define TARGET_ASM_FILE_START_FILE_DIRECTIVE true 97 98 /* This is how to allocate empty space in some section. The .zero 99 pseudo-op is used for this on most svr4 assemblers. */ 100 101 #define SKIP_ASM_OP "\t.zero\t" 102 103 #undef ASM_OUTPUT_SKIP 104 #define ASM_OUTPUT_SKIP(FILE, SIZE) \ 105 fprintf ((FILE), "%s"HOST_WIDE_INT_PRINT_UNSIGNED"\n",\ 106 SKIP_ASM_OP, (SIZE)) 107 108 /* This is how to store into the string LABEL 109 the symbol_ref name of an internal numbered label where 110 PREFIX is the class of label and NUM is the number within the class. 111 This is suitable for output with `assemble_name'. 112 113 For most svr4 systems, the convention is that any symbol which begins 114 with a period is not put into the linker symbol table by the assembler. */ 115 116 #undef ASM_GENERATE_INTERNAL_LABEL 117 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \ 118 do \ 119 { \ 120 sprintf (LABEL, "*.%s%u", PREFIX, (unsigned) (NUM)); \ 121 } \ 122 while (0) 123 124 /* Output the label which precedes a jumptable. Note that for all svr4 125 systems where we actually generate jumptables (which is to say every 126 svr4 target except i386, where we use casesi instead) we put the jump- 127 tables into the .rodata section and since other stuff could have been 128 put into the .rodata section prior to any given jumptable, we have to 129 make sure that the location counter for the .rodata section gets pro- 130 perly re-aligned prior to the actual beginning of the jump table. */ 131 132 #undef ALIGN_ASM_OP 133 #define ALIGN_ASM_OP "\t.align\t" 134 135 #ifndef ASM_OUTPUT_BEFORE_CASE_LABEL 136 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) \ 137 ASM_OUTPUT_ALIGN ((FILE), 2); 138 #endif 139 140 #undef ASM_OUTPUT_CASE_LABEL 141 #define ASM_OUTPUT_CASE_LABEL(FILE, PREFIX, NUM, JUMPTABLE) \ 142 do \ 143 { \ 144 ASM_OUTPUT_BEFORE_CASE_LABEL (FILE, PREFIX, NUM, JUMPTABLE) \ 145 (*targetm.asm_out.internal_label) (FILE, PREFIX, NUM); \ 146 } \ 147 while (0) 148 149 /* The standard SVR4 assembler seems to require that certain builtin 150 library routines (e.g. .udiv) be explicitly declared as .globl 151 in each assembly file where they are referenced. */ 152 153 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \ 154 (*targetm.asm_out.globalize_label) (FILE, XSTR (FUN, 0)) 155 156 /* This says how to output assembler code to declare an 157 uninitialized external linkage data object. Under SVR4, 158 the linker seems to want the alignment of data objects 159 to depend on their types. We do exactly that here. */ 160 161 #define COMMON_ASM_OP "\t.comm\t" 162 163 #undef ASM_OUTPUT_ALIGNED_COMMON 164 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \ 165 do \ 166 { \ 167 fprintf ((FILE), "%s", COMMON_ASM_OP); \ 168 assemble_name ((FILE), (NAME)); \ 169 fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \ 170 (SIZE), (ALIGN) / BITS_PER_UNIT); \ 171 } \ 172 while (0) 173 174 /* This says how to output assembler code to declare an 175 uninitialized internal linkage data object. Under SVR4, 176 the linker seems to want the alignment of data objects 177 to depend on their types. We do exactly that here. */ 178 179 #define LOCAL_ASM_OP "\t.local\t" 180 181 #undef ASM_OUTPUT_ALIGNED_LOCAL 182 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN) \ 183 do \ 184 { \ 185 fprintf ((FILE), "%s", LOCAL_ASM_OP); \ 186 assemble_name ((FILE), (NAME)); \ 187 fprintf ((FILE), "\n"); \ 188 ASM_OUTPUT_ALIGNED_COMMON (FILE, NAME, SIZE, ALIGN); \ 189 } \ 190 while (0) 191 192 /* This is the pseudo-op used to generate a contiguous sequence of byte 193 values from a double-quoted string WITHOUT HAVING A TERMINATING NUL 194 AUTOMATICALLY APPENDED. This is the same for most svr4 assemblers. */ 195 196 #undef ASCII_DATA_ASM_OP 197 #define ASCII_DATA_ASM_OP "\t.ascii\t" 198 199 /* Support a read-only data section. */ 200 #define READONLY_DATA_SECTION_ASM_OP "\t.section\t.rodata" 201 202 /* On svr4, we *do* have support for the .init and .fini sections, and we 203 can put stuff in there to be executed before and after `main'. We let 204 crtstuff.c and other files know this by defining the following symbols. 205 The definitions say how to change sections to the .init and .fini 206 sections. This is the same for all known svr4 assemblers. */ 207 208 #define INIT_SECTION_ASM_OP "\t.section\t.init" 209 #define FINI_SECTION_ASM_OP "\t.section\t.fini" 210 211 /* Output assembly directive to move to the beginning of current section. */ 212 #ifdef HAVE_GAS_SUBSECTION_ORDERING 213 # define ASM_SECTION_START_OP "\t.subsection\t-1" 214 # define ASM_OUTPUT_SECTION_START(FILE) \ 215 fprintf ((FILE), "%s\n", ASM_SECTION_START_OP) 216 #endif 217 218 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1) 219 220 /* Switch into a generic section. */ 221 #define TARGET_ASM_NAMED_SECTION default_elf_asm_named_section 222 223 #undef TARGET_ASM_SELECT_RTX_SECTION 224 #define TARGET_ASM_SELECT_RTX_SECTION default_elf_select_rtx_section 225 #undef TARGET_ASM_SELECT_SECTION 226 #define TARGET_ASM_SELECT_SECTION default_elf_select_section 227 #undef TARGET_HAVE_SWITCHABLE_BSS_SECTIONS 228 #define TARGET_HAVE_SWITCHABLE_BSS_SECTIONS true 229 230 /* Define the strings used for the special svr4 .type and .size directives. 231 These strings generally do not vary from one system running svr4 to 232 another, but if a given system (e.g. m88k running svr) needs to use 233 different pseudo-op names for these, they may be overridden in the 234 file which includes this one. */ 235 236 #define TYPE_ASM_OP "\t.type\t" 237 #define SIZE_ASM_OP "\t.size\t" 238 239 /* This is how we tell the assembler that a symbol is weak. */ 240 241 #define ASM_WEAKEN_LABEL(FILE, NAME) \ 242 do \ 243 { \ 244 fputs ("\t.weak\t", (FILE)); \ 245 assemble_name ((FILE), (NAME)); \ 246 fputc ('\n', (FILE)); \ 247 } \ 248 while (0) 249 250 /* The following macro defines the format used to output the second 251 operand of the .type assembler directive. Different svr4 assemblers 252 expect various different forms for this operand. The one given here 253 is just a default. You may need to override it in your machine- 254 specific tm.h file (depending upon the particulars of your assembler). */ 255 256 #define TYPE_OPERAND_FMT "@%s" 257 258 /* Write the extra assembler code needed to declare a function's result. 259 Most svr4 assemblers don't require any special declaration of the 260 result value, but there are exceptions. */ 261 262 #ifndef ASM_DECLARE_RESULT 263 #define ASM_DECLARE_RESULT(FILE, RESULT) 264 #endif 265 266 /* These macros generate the special .type and .size directives which 267 are used to set the corresponding fields of the linker symbol table 268 entries in an ELF object file under SVR4. These macros also output 269 the starting labels for the relevant functions/objects. */ 270 271 /* Write the extra assembler code needed to declare a function properly. 272 Some svr4 assemblers need to also have something extra said about the 273 function's return value. We allow for that here. */ 274 275 #ifndef ASM_DECLARE_FUNCTION_NAME 276 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \ 277 do \ 278 { \ 279 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \ 280 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \ 281 ASM_OUTPUT_FUNCTION_LABEL (FILE, NAME, DECL); \ 282 } \ 283 while (0) 284 #endif 285 286 /* Write the extra assembler code needed to declare an object properly. */ 287 288 #ifdef HAVE_GAS_GNU_UNIQUE_OBJECT 289 #define USE_GNU_UNIQUE_OBJECT 1 290 #else 291 #define USE_GNU_UNIQUE_OBJECT 0 292 #endif 293 294 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL) \ 295 do \ 296 { \ 297 HOST_WIDE_INT size; \ 298 \ 299 /* For template static data member instantiations or \ 300 inline fn local statics and their guard variables, use \ 301 gnu_unique_object so that they will be combined even under \ 302 RTLD_LOCAL. Don't use gnu_unique_object for typeinfo, \ 303 vtables and other read-only artificial decls. */ \ 304 if (USE_GNU_UNIQUE_OBJECT && DECL_ONE_ONLY (DECL) \ 305 && (!DECL_ARTIFICIAL (DECL) || !TREE_READONLY (DECL))) \ 306 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "gnu_unique_object"); \ 307 else \ 308 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object"); \ 309 \ 310 size_directive_output = 0; \ 311 if (!flag_inhibit_size_directive \ 312 && (DECL) && DECL_SIZE (DECL)) \ 313 { \ 314 size_directive_output = 1; \ 315 size = int_size_in_bytes (TREE_TYPE (DECL)); \ 316 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size); \ 317 } \ 318 \ 319 ASM_OUTPUT_LABEL (FILE, NAME); \ 320 } \ 321 while (0) 322 323 /* Output the size directive for a decl in rest_of_decl_compilation 324 in the case where we did not do so before the initializer. 325 Once we find the error_mark_node, we know that the value of 326 size_directive_output was set 327 by ASM_DECLARE_OBJECT_NAME when it was run for the same decl. */ 328 329 #undef ASM_FINISH_DECLARE_OBJECT 330 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)\ 331 do \ 332 { \ 333 const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0); \ 334 HOST_WIDE_INT size; \ 335 \ 336 if (!flag_inhibit_size_directive \ 337 && DECL_SIZE (DECL) \ 338 && ! AT_END && TOP_LEVEL \ 339 && DECL_INITIAL (DECL) == error_mark_node \ 340 && !size_directive_output) \ 341 { \ 342 size_directive_output = 1; \ 343 size = int_size_in_bytes (TREE_TYPE (DECL)); \ 344 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size); \ 345 } \ 346 } \ 347 while (0) 348 349 /* This is how to declare the size of a function. */ 350 #ifndef ASM_DECLARE_FUNCTION_SIZE 351 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \ 352 do \ 353 { \ 354 if (!flag_inhibit_size_directive) \ 355 ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME); \ 356 } \ 357 while (0) 358 #endif 359 360 /* A table of bytes codes used by the ASM_OUTPUT_ASCII and 361 ASM_OUTPUT_LIMITED_STRING macros. Each byte in the table 362 corresponds to a particular byte value [0..255]. For any 363 given byte value, if the value in the corresponding table 364 position is zero, the given character can be output directly. 365 If the table value is 1, the byte must be output as a \ooo 366 octal escape. If the tables value is anything else, then the 367 byte value should be output as a \ followed by the value 368 in the table. Note that we can use standard UN*X escape 369 sequences for many control characters, but we don't use 370 \a to represent BEL because some svr4 assemblers (e.g. on 371 the i386) don't know about that. Also, we don't use \v 372 since some versions of gas, such as 2.2 did not accept it. */ 373 374 #define ESCAPES \ 375 "\1\1\1\1\1\1\1\1btn\1fr\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\ 376 \0\0\"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\ 377 \0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\\\0\0\0\ 378 \0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\1\ 379 \1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\ 380 \1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\ 381 \1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\ 382 \1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1" 383 384 /* Some svr4 assemblers have a limit on the number of characters which 385 can appear in the operand of a .string directive. If your assembler 386 has such a limitation, you should define STRING_LIMIT to reflect that 387 limit. Note that at least some svr4 assemblers have a limit on the 388 actual number of bytes in the double-quoted string, and that they 389 count each character in an escape sequence as one byte. Thus, an 390 escape sequence like \377 would count as four bytes. 391 392 If your target assembler doesn't support the .string directive, you 393 should define this to zero. 394 */ 395 396 #define STRING_LIMIT ((unsigned) 256) 397 398 #define STRING_ASM_OP "\t.string\t" 399 400 /* The routine used to output NUL terminated strings. We use a special 401 version of this for most svr4 targets because doing so makes the 402 generated assembly code more compact (and thus faster to assemble) 403 as well as more readable, especially for targets like the i386 404 (where the only alternative is to output character sequences as 405 comma separated lists of numbers). */ 406 407 #define ASM_OUTPUT_LIMITED_STRING(FILE, STR) \ 408 do \ 409 { \ 410 register const unsigned char *_limited_str = \ 411 (const unsigned char *) (STR); \ 412 register unsigned ch; \ 413 \ 414 fprintf ((FILE), "%s\"", STRING_ASM_OP); \ 415 \ 416 for (; (ch = *_limited_str); _limited_str++) \ 417 { \ 418 register int escape; \ 419 \ 420 switch (escape = ESCAPES[ch]) \ 421 { \ 422 case 0: \ 423 putc (ch, (FILE)); \ 424 break; \ 425 case 1: \ 426 fprintf ((FILE), "\\%03o", ch); \ 427 break; \ 428 default: \ 429 putc ('\\', (FILE)); \ 430 putc (escape, (FILE)); \ 431 break; \ 432 } \ 433 } \ 434 \ 435 fprintf ((FILE), "\"\n"); \ 436 } \ 437 while (0) 438 439 /* The routine used to output sequences of byte values. We use a special 440 version of this for most svr4 targets because doing so makes the 441 generated assembly code more compact (and thus faster to assemble) 442 as well as more readable. Note that if we find subparts of the 443 character sequence which end with NUL (and which are shorter than 444 STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING. */ 445 446 #undef ASM_OUTPUT_ASCII 447 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH) \ 448 do \ 449 { \ 450 const unsigned char *_ascii_bytes = \ 451 (const unsigned char *) (STR); \ 452 const unsigned char *limit = _ascii_bytes + (LENGTH); \ 453 const unsigned char *last_null = NULL; \ 454 unsigned bytes_in_chunk = 0; \ 455 \ 456 for (; _ascii_bytes < limit; _ascii_bytes++) \ 457 { \ 458 const unsigned char *p; \ 459 \ 460 if (bytes_in_chunk >= 60) \ 461 { \ 462 fprintf ((FILE), "\"\n"); \ 463 bytes_in_chunk = 0; \ 464 } \ 465 \ 466 if (_ascii_bytes > last_null) \ 467 { \ 468 for (p = _ascii_bytes; p < limit && *p != '\0'; p++) \ 469 continue; \ 470 last_null = p; \ 471 } \ 472 else \ 473 p = last_null; \ 474 \ 475 if (p < limit && (p - _ascii_bytes) <= (long)STRING_LIMIT) \ 476 { \ 477 if (bytes_in_chunk > 0) \ 478 { \ 479 fprintf ((FILE), "\"\n"); \ 480 bytes_in_chunk = 0; \ 481 } \ 482 \ 483 ASM_OUTPUT_LIMITED_STRING ((FILE), _ascii_bytes); \ 484 _ascii_bytes = p; \ 485 } \ 486 else \ 487 { \ 488 register int escape; \ 489 register unsigned ch; \ 490 \ 491 if (bytes_in_chunk == 0) \ 492 fprintf ((FILE), "%s\"", ASCII_DATA_ASM_OP); \ 493 \ 494 switch (escape = ESCAPES[ch = *_ascii_bytes]) \ 495 { \ 496 case 0: \ 497 putc (ch, (FILE)); \ 498 bytes_in_chunk++; \ 499 break; \ 500 case 1: \ 501 fprintf ((FILE), "\\%03o", ch); \ 502 bytes_in_chunk += 4; \ 503 break; \ 504 default: \ 505 putc ('\\', (FILE)); \ 506 putc (escape, (FILE)); \ 507 bytes_in_chunk += 2; \ 508 break; \ 509 } \ 510 } \ 511 } \ 512 \ 513 if (bytes_in_chunk > 0) \ 514 fprintf ((FILE), "\"\n"); \ 515 } \ 516 while (0) 517 518 /* Allow the use of the -frecord-gcc-switches switch via the 519 elf_record_gcc_switches function defined in varasm.c. */ 520 #undef TARGET_ASM_RECORD_GCC_SWITCHES 521 #define TARGET_ASM_RECORD_GCC_SWITCHES elf_record_gcc_switches 522 523 /* A C statement (sans semicolon) to output to the stdio stream STREAM 524 any text necessary for declaring the name of an external symbol 525 named NAME which is referenced in this compilation but not defined. 526 It is needed to properly support non-default visibility. */ 527 528 #ifndef ASM_OUTPUT_EXTERNAL 529 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \ 530 default_elf_asm_output_external (FILE, DECL, NAME) 531 #endif 532
