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@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 char *__p; \ 121 (LABEL)[0] = '*'; \ 122 (LABEL)[1] = '.'; \ 123 __p = stpcpy (&(LABEL)[2], PREFIX); \ 124 sprint_ul (__p, (unsigned long) (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_FUNCTION_LABEL (FILE, NAME, DECL); \ 286 } \ 287 while (0) 288 #endif 289 290 /* Write the extra assembler code needed to declare an object properly. */ 291 292 #ifdef HAVE_GAS_GNU_UNIQUE_OBJECT 293 #define USE_GNU_UNIQUE_OBJECT 1 294 #else 295 #define USE_GNU_UNIQUE_OBJECT 0 296 #endif 297 298 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL) \ 299 do \ 300 { \ 301 HOST_WIDE_INT size; \ 302 \ 303 /* For template static data member instantiations or \ 304 inline fn local statics and their guard variables, use \ 305 gnu_unique_object so that they will be combined even under \ 306 RTLD_LOCAL. Don't use gnu_unique_object for typeinfo, \ 307 vtables and other read-only artificial decls. */ \ 308 if (USE_GNU_UNIQUE_OBJECT && DECL_ONE_ONLY (DECL) \ 309 && (!DECL_ARTIFICIAL (DECL) || !TREE_READONLY (DECL))) \ 310 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "gnu_unique_object"); \ 311 else \ 312 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object"); \ 313 \ 314 size_directive_output = 0; \ 315 if (!flag_inhibit_size_directive \ 316 && (DECL) && DECL_SIZE (DECL)) \ 317 { \ 318 size_directive_output = 1; \ 319 size = int_size_in_bytes (TREE_TYPE (DECL)); \ 320 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size); \ 321 } \ 322 \ 323 ASM_OUTPUT_LABEL (FILE, NAME); \ 324 } \ 325 while (0) 326 327 /* Output the size directive for a decl in rest_of_decl_compilation 328 in the case where we did not do so before the initializer. 329 Once we find the error_mark_node, we know that the value of 330 size_directive_output was set 331 by ASM_DECLARE_OBJECT_NAME when it was run for the same decl. */ 332 333 #undef ASM_FINISH_DECLARE_OBJECT 334 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)\ 335 do \ 336 { \ 337 const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0); \ 338 HOST_WIDE_INT size; \ 339 \ 340 if (!flag_inhibit_size_directive \ 341 && DECL_SIZE (DECL) \ 342 && ! AT_END && TOP_LEVEL \ 343 && DECL_INITIAL (DECL) == error_mark_node \ 344 && !size_directive_output) \ 345 { \ 346 size_directive_output = 1; \ 347 size = int_size_in_bytes (TREE_TYPE (DECL)); \ 348 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size); \ 349 } \ 350 } \ 351 while (0) 352 353 /* This is how to declare the size of a function. */ 354 #ifndef ASM_DECLARE_FUNCTION_SIZE 355 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \ 356 do \ 357 { \ 358 if (!flag_inhibit_size_directive) \ 359 ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME); \ 360 } \ 361 while (0) 362 #endif 363 364 /* A table of bytes codes used by the ASM_OUTPUT_ASCII and 365 ASM_OUTPUT_LIMITED_STRING macros. Each byte in the table 366 corresponds to a particular byte value [0..255]. For any 367 given byte value, if the value in the corresponding table 368 position is zero, the given character can be output directly. 369 If the table value is 1, the byte must be output as a \ooo 370 octal escape. If the tables value is anything else, then the 371 byte value should be output as a \ followed by the value 372 in the table. Note that we can use standard UN*X escape 373 sequences for many control characters, but we don't use 374 \a to represent BEL because some svr4 assemblers (e.g. on 375 the i386) don't know about that. Also, we don't use \v 376 since some versions of gas, such as 2.2 did not accept it. */ 377 378 #define ELF_ASCII_ESCAPES \ 379 "\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\ 380 \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\ 381 \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\ 382 \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\ 383 \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\ 384 \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\ 385 \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\ 386 \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" 387 388 /* Some svr4 assemblers have a limit on the number of characters which 389 can appear in the operand of a .string directive. If your assembler 390 has such a limitation, you should define STRING_LIMIT to reflect that 391 limit. Note that at least some svr4 assemblers have a limit on the 392 actual number of bytes in the double-quoted string, and that they 393 count each character in an escape sequence as one byte. Thus, an 394 escape sequence like \377 would count as four bytes. 395 396 If your target assembler doesn't support the .string directive, you 397 should define this to zero. 398 */ 399 400 #define ELF_STRING_LIMIT ((unsigned) 256) 401 402 #define STRING_ASM_OP "\t.string\t" 403 404 /* The routine used to output NUL terminated strings. We use a special 405 version of this for most svr4 targets because doing so makes the 406 generated assembly code more compact (and thus faster to assemble) 407 as well as more readable, especially for targets like the i386 408 (where the only alternative is to output character sequences as 409 comma separated lists of numbers). */ 410 411 #define ASM_OUTPUT_LIMITED_STRING(FILE, STR) \ 412 default_elf_asm_output_limited_string ((FILE), (STR)) 413 414 /* The routine used to output sequences of byte values. We use a special 415 version of this for most svr4 targets because doing so makes the 416 generated assembly code more compact (and thus faster to assemble) 417 as well as more readable. Note that if we find subparts of the 418 character sequence which end with NUL (and which are shorter than 419 STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING. */ 420 421 #undef ASM_OUTPUT_ASCII 422 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH) \ 423 default_elf_asm_output_ascii ((FILE), (STR), (LENGTH)); 424 425 /* Allow the use of the -frecord-gcc-switches switch via the 426 elf_record_gcc_switches function defined in varasm.c. */ 427 #undef TARGET_ASM_RECORD_GCC_SWITCHES 428 #define TARGET_ASM_RECORD_GCC_SWITCHES elf_record_gcc_switches 429 430 /* A C statement (sans semicolon) to output to the stdio stream STREAM 431 any text necessary for declaring the name of an external symbol 432 named NAME which is referenced in this compilation but not defined. 433 It is needed to properly support non-default visibility. */ 434 435 #ifndef ASM_OUTPUT_EXTERNAL 436 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \ 437 default_elf_asm_output_external (FILE, DECL, NAME) 438 #endif 439