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