1 /* elfos.h -- operating system specific defines to be used when 2 targeting GCC for some generic ELF system 3 Copyright (C) 1991-2020 Free Software Foundation, Inc. 4 Based on svr4.h contributed by Ron Guilmette (rfg@netcom.com). 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 Under Section 7 of GPL version 3, you are granted additional 19 permissions described in the GCC Runtime Library Exception, version 20 3.1, as published by the Free Software Foundation. 21 22 You should have received a copy of the GNU General Public License and 23 a copy of the GCC Runtime Library Exception along with this program; 24 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 25 <http://www.gnu.org/licenses/>. */ 26 27 #define TARGET_OBJFMT_CPP_BUILTINS() \ 28 do \ 29 { \ 30 builtin_define ("__ELF__"); \ 31 } \ 32 while (0) 33 34 /* Define a symbol indicating that we are using elfos.h. 35 Some CPU specific configuration files use this. */ 36 #define USING_ELFOS_H 37 38 /* The prefix to add to user-visible assembler symbols. 39 40 For ELF systems the convention is *not* to prepend a leading 41 underscore onto user-level symbol names. */ 42 43 #undef USER_LABEL_PREFIX 44 #define USER_LABEL_PREFIX "" 45 46 /* The biggest alignment supported by ELF in bits. 32-bit ELF 47 supports section alignment up to (0x80000000 * 8), while 48 64-bit ELF supports (0x8000000000000000 * 8). If this macro 49 is not defined, the default is the largest alignment supported 50 by 32-bit ELF and representable on a 32-bit host. Use this 51 macro to limit the alignment which can be specified using 52 the `__attribute__ ((aligned (N)))' construct. */ 53 #ifndef MAX_OFILE_ALIGNMENT 54 #define MAX_OFILE_ALIGNMENT (((unsigned int) 1 << 28) * 8) 55 #endif 56 57 /* Use periods rather than dollar signs in special g++ assembler names. */ 58 59 #define NO_DOLLAR_IN_LABEL 60 61 /* Writing `int' for a bit-field forces int alignment for the structure. */ 62 63 #ifndef PCC_BITFIELD_TYPE_MATTERS 64 #define PCC_BITFIELD_TYPE_MATTERS 1 65 #endif 66 67 /* All ELF targets can support DWARF-2. */ 68 69 #define DWARF2_DEBUGGING_INFO 1 70 71 /* The GNU tools operate better with dwarf2, and it is required by some 72 psABI's. Since we don't have any native tools to be compatible with, 73 default to dwarf2. */ 74 75 #ifndef PREFERRED_DEBUGGING_TYPE 76 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG 77 #endif 78 79 /* All SVR4 targets use the ELF object file format. */ 80 #define OBJECT_FORMAT_ELF 81 82 83 /* Output #ident as a .ident. */ 84 85 #undef TARGET_ASM_OUTPUT_IDENT 86 #define TARGET_ASM_OUTPUT_IDENT default_asm_output_ident_directive 87 88 #undef SET_ASM_OP 89 #define SET_ASM_OP "\t.set\t" 90 91 /* Most svr4 assemblers want a .file directive at the beginning of 92 their input file. */ 93 #define TARGET_ASM_FILE_START_FILE_DIRECTIVE true 94 95 /* This is how to allocate empty space in some section. The .zero 96 pseudo-op is used for this on most svr4 assemblers. */ 97 98 #define SKIP_ASM_OP "\t.zero\t" 99 100 #undef ASM_OUTPUT_SKIP 101 #define ASM_OUTPUT_SKIP(FILE, SIZE) \ 102 fprintf ((FILE), "%s" HOST_WIDE_INT_PRINT_UNSIGNED "\n",\ 103 SKIP_ASM_OP, (SIZE)) 104 105 /* This is how to store into the string LABEL 106 the symbol_ref name of an internal numbered label where 107 PREFIX is the class of label and NUM is the number within the class. 108 This is suitable for output with `assemble_name'. 109 110 For most svr4 systems, the convention is that any symbol which begins 111 with a period is not put into the linker symbol table by the assembler. */ 112 113 #undef ASM_GENERATE_INTERNAL_LABEL 114 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \ 115 do \ 116 { \ 117 char *__p; \ 118 (LABEL)[0] = '*'; \ 119 (LABEL)[1] = '.'; \ 120 __p = stpcpy (&(LABEL)[2], PREFIX); \ 121 sprint_ul (__p, (unsigned long) (NUM)); \ 122 } \ 123 while (0) 124 125 /* Output the label which precedes a jumptable. Note that for all svr4 126 systems where we actually generate jumptables (which is to say every 127 svr4 target except i386, where we use casesi instead) we put the jump- 128 tables into the .rodata section and since other stuff could have been 129 put into the .rodata section prior to any given jumptable, we have to 130 make sure that the location counter for the .rodata section gets pro- 131 perly re-aligned prior to the actual beginning of the jump table. */ 132 133 #undef ALIGN_ASM_OP 134 #define ALIGN_ASM_OP "\t.align\t" 135 136 #ifndef ASM_OUTPUT_BEFORE_CASE_LABEL 137 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) \ 138 ASM_OUTPUT_ALIGN ((FILE), 2) 139 #endif 140 141 #undef ASM_OUTPUT_CASE_LABEL 142 #define ASM_OUTPUT_CASE_LABEL(FILE, PREFIX, NUM, JUMPTABLE) \ 143 do \ 144 { \ 145 ASM_OUTPUT_BEFORE_CASE_LABEL (FILE, PREFIX, NUM, JUMPTABLE); \ 146 (*targetm.asm_out.internal_label) (FILE, PREFIX, NUM); \ 147 } \ 148 while (0) 149 150 /* The standard SVR4 assembler seems to require that certain builtin 151 library routines (e.g. .udiv) be explicitly declared as .globl 152 in each assembly file where they are referenced. */ 153 154 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \ 155 (*targetm.asm_out.globalize_label) (FILE, XSTR (FUN, 0)) 156 157 /* This says how to output assembler code to declare an 158 uninitialized external linkage data object. Under SVR4, 159 the linker seems to want the alignment of data objects 160 to depend on their types. We do exactly that here. */ 161 162 #define COMMON_ASM_OP "\t.comm\t" 163 164 #undef ASM_OUTPUT_ALIGNED_COMMON 165 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \ 166 do \ 167 { \ 168 fprintf ((FILE), "%s", COMMON_ASM_OP); \ 169 assemble_name ((FILE), (NAME)); \ 170 fprintf ((FILE), "," HOST_WIDE_INT_PRINT_UNSIGNED ",%u\n", \ 171 (SIZE), (ALIGN) / BITS_PER_UNIT); \ 172 } \ 173 while (0) 174 175 /* This says how to output assembler code to declare an 176 uninitialized internal linkage data object. Under SVR4, 177 the linker seems to want the alignment of data objects 178 to depend on their types. We do exactly that here. */ 179 180 #define LOCAL_ASM_OP "\t.local\t" 181 182 #undef ASM_OUTPUT_ALIGNED_LOCAL 183 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN) \ 184 do \ 185 { \ 186 fprintf ((FILE), "%s", LOCAL_ASM_OP); \ 187 assemble_name ((FILE), (NAME)); \ 188 fprintf ((FILE), "\n"); \ 189 ASM_OUTPUT_ALIGNED_COMMON (FILE, NAME, SIZE, ALIGN); \ 190 } \ 191 while (0) 192 193 /* This is the pseudo-op used to generate a contiguous sequence of byte 194 values from a double-quoted string WITHOUT HAVING A TERMINATING NUL 195 AUTOMATICALLY APPENDED. This is the same for most svr4 assemblers. */ 196 197 #undef ASCII_DATA_ASM_OP 198 #define ASCII_DATA_ASM_OP "\t.ascii\t" 199 200 /* Support a read-only data section. */ 201 #define READONLY_DATA_SECTION_ASM_OP "\t.section\t.rodata" 202 203 /* On svr4, we *do* have support for the .init and .fini sections, and we 204 can put stuff in there to be executed before and after `main'. We let 205 crtstuff.c and other files know this by defining the following symbols. 206 The definitions say how to change sections to the .init and .fini 207 sections. This is the same for all known svr4 assemblers. */ 208 209 #define INIT_SECTION_ASM_OP "\t.section\t.init" 210 #define FINI_SECTION_ASM_OP "\t.section\t.fini" 211 212 /* Output assembly directive to move to the beginning of current section. */ 213 #ifdef HAVE_GAS_SUBSECTION_ORDERING 214 # define ASM_SECTION_START_OP "\t.subsection\t-1" 215 # define ASM_OUTPUT_SECTION_START(FILE) \ 216 fprintf ((FILE), "%s\n", ASM_SECTION_START_OP) 217 #endif 218 219 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1) 220 221 /* Switch into a generic section. */ 222 #define TARGET_ASM_NAMED_SECTION default_elf_asm_named_section 223 224 #undef TARGET_ASM_SELECT_RTX_SECTION 225 #define TARGET_ASM_SELECT_RTX_SECTION default_elf_select_rtx_section 226 #undef TARGET_ASM_SELECT_SECTION 227 #define TARGET_ASM_SELECT_SECTION default_elf_select_section 228 #undef TARGET_HAVE_SWITCHABLE_BSS_SECTIONS 229 #define TARGET_HAVE_SWITCHABLE_BSS_SECTIONS true 230 231 /* Define the strings used for the special svr4 .type and .size directives. 232 These strings generally do not vary from one system running svr4 to 233 another, but if a given system (e.g. m88k running svr) needs to use 234 different pseudo-op names for these, they may be overridden in the 235 file which includes this one. */ 236 237 #define TYPE_ASM_OP "\t.type\t" 238 #define SIZE_ASM_OP "\t.size\t" 239 240 /* This is how we tell the assembler that a symbol is weak. */ 241 242 #define ASM_WEAKEN_LABEL(FILE, NAME) \ 243 do \ 244 { \ 245 fputs ("\t.weak\t", (FILE)); \ 246 assemble_name ((FILE), (NAME)); \ 247 fputc ('\n', (FILE)); \ 248 } \ 249 while (0) 250 251 #define ASM_OUTPUT_SYMVER_DIRECTIVE(FILE, NAME, NAME2) \ 252 do \ 253 { \ 254 fputs ("\t.symver\t", (FILE)); \ 255 assemble_name ((FILE), (NAME)); \ 256 fputs (", ", (FILE)); \ 257 assemble_name ((FILE), (NAME2)); \ 258 fputc ('\n', (FILE)); \ 259 } \ 260 while (0) 261 262 /* The following macro defines the format used to output the second 263 operand of the .type assembler directive. Different svr4 assemblers 264 expect various different forms for this operand. The one given here 265 is just a default. You may need to override it in your machine- 266 specific tm.h file (depending upon the particulars of your assembler). */ 267 268 #define TYPE_OPERAND_FMT "@%s" 269 270 /* Write the extra assembler code needed to declare a function's result. 271 Most svr4 assemblers don't require any special declaration of the 272 result value, but there are exceptions. */ 273 274 #ifndef ASM_DECLARE_RESULT 275 #define ASM_DECLARE_RESULT(FILE, RESULT) 276 #endif 277 278 /* These macros generate the special .type and .size directives which 279 are used to set the corresponding fields of the linker symbol table 280 entries in an ELF object file under SVR4. These macros also output 281 the starting labels for the relevant functions/objects. */ 282 283 /* Write the extra assembler code needed to declare a function properly. 284 Some svr4 assemblers need to also have something extra said about the 285 function's return value. We allow for that here. */ 286 287 #ifndef ASM_DECLARE_FUNCTION_NAME 288 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \ 289 do \ 290 { \ 291 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \ 292 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \ 293 ASM_OUTPUT_FUNCTION_LABEL (FILE, NAME, DECL); \ 294 } \ 295 while (0) 296 #endif 297 298 /* Write the extra assembler code needed to declare the name of a 299 cold function partition properly. Some svr4 assemblers need to also 300 have something extra said about the function's return value. We 301 allow for that here. */ 302 303 #ifndef ASM_DECLARE_COLD_FUNCTION_NAME 304 #define ASM_DECLARE_COLD_FUNCTION_NAME(FILE, NAME, DECL) \ 305 do \ 306 { \ 307 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \ 308 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \ 309 ASM_OUTPUT_FUNCTION_LABEL (FILE, NAME, DECL); \ 310 } \ 311 while (0) 312 #endif 313 314 /* Write the extra assembler code needed to declare an object properly. */ 315 316 #ifdef HAVE_GAS_GNU_UNIQUE_OBJECT 317 #define USE_GNU_UNIQUE_OBJECT flag_gnu_unique 318 #else 319 #define USE_GNU_UNIQUE_OBJECT 0 320 #endif 321 322 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL) \ 323 do \ 324 { \ 325 HOST_WIDE_INT size; \ 326 \ 327 /* For template static data member instantiations or \ 328 inline fn local statics and their guard variables, use \ 329 gnu_unique_object so that they will be combined even under \ 330 RTLD_LOCAL. Don't use gnu_unique_object for typeinfo, \ 331 vtables and other read-only artificial decls. */ \ 332 if (USE_GNU_UNIQUE_OBJECT && DECL_ONE_ONLY (DECL) \ 333 && (!DECL_ARTIFICIAL (DECL) || !TREE_READONLY (DECL))) \ 334 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "gnu_unique_object"); \ 335 else \ 336 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object"); \ 337 \ 338 size_directive_output = 0; \ 339 if (!flag_inhibit_size_directive \ 340 && (DECL) && DECL_SIZE (DECL)) \ 341 { \ 342 size_directive_output = 1; \ 343 size = tree_to_uhwi (DECL_SIZE_UNIT (DECL)); \ 344 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size); \ 345 } \ 346 \ 347 ASM_OUTPUT_LABEL (FILE, NAME); \ 348 } \ 349 while (0) 350 351 /* Output the size directive for a decl in rest_of_decl_compilation 352 in the case where we did not do so before the initializer. 353 Once we find the error_mark_node, we know that the value of 354 size_directive_output was set 355 by ASM_DECLARE_OBJECT_NAME when it was run for the same decl. */ 356 357 #undef ASM_FINISH_DECLARE_OBJECT 358 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)\ 359 do \ 360 { \ 361 const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0); \ 362 HOST_WIDE_INT size; \ 363 \ 364 if (!flag_inhibit_size_directive \ 365 && DECL_SIZE (DECL) \ 366 && ! AT_END && TOP_LEVEL \ 367 && DECL_INITIAL (DECL) == error_mark_node \ 368 && !size_directive_output) \ 369 { \ 370 size_directive_output = 1; \ 371 size = tree_to_uhwi (DECL_SIZE_UNIT (DECL)); \ 372 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size); \ 373 } \ 374 } \ 375 while (0) 376 377 /* This is how to declare the size of a function. */ 378 #ifndef ASM_DECLARE_FUNCTION_SIZE 379 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \ 380 do \ 381 { \ 382 if (!flag_inhibit_size_directive) \ 383 ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME); \ 384 } \ 385 while (0) 386 #endif 387 388 /* This is how to declare the size of a cold function partition. */ 389 #ifndef ASM_DECLARE_COLD_FUNCTION_SIZE 390 #define ASM_DECLARE_COLD_FUNCTION_SIZE(FILE, FNAME, DECL) \ 391 do \ 392 { \ 393 if (!flag_inhibit_size_directive) \ 394 ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME); \ 395 } \ 396 while (0) 397 #endif 398 399 /* A table of bytes codes used by the ASM_OUTPUT_ASCII and 400 ASM_OUTPUT_LIMITED_STRING macros. Each byte in the table 401 corresponds to a particular byte value [0..255]. For any 402 given byte value, if the value in the corresponding table 403 position is zero, the given character can be output directly. 404 If the table value is 1, the byte must be output as a \ooo 405 octal escape. If the tables value is anything else, then the 406 byte value should be output as a \ followed by the value 407 in the table. Note that we can use standard UN*X escape 408 sequences for many control characters, but we don't use 409 \a to represent BEL because some svr4 assemblers (e.g. on 410 the i386) don't know about that. Also, we don't use \v 411 since some versions of gas, such as 2.2 did not accept it. */ 412 413 #define ELF_ASCII_ESCAPES \ 414 "\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\ 415 \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\ 416 \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\ 417 \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\ 418 \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\ 419 \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\ 420 \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\ 421 \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" 422 423 /* Some svr4 assemblers have a limit on the number of characters which 424 can appear in the operand of a .string directive. If your assembler 425 has such a limitation, you should define STRING_LIMIT to reflect that 426 limit. Note that at least some svr4 assemblers have a limit on the 427 actual number of bytes in the double-quoted string, and that they 428 count each character in an escape sequence as one byte. Thus, an 429 escape sequence like \377 would count as four bytes. 430 431 If your target assembler doesn't support the .string directive, you 432 should define this to zero. 433 */ 434 435 #define ELF_STRING_LIMIT ((unsigned) 256) 436 437 #define STRING_ASM_OP "\t.string\t" 438 439 /* The routine used to output NUL terminated strings. 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, especially for targets like the i386 443 (where the only alternative is to output character sequences as 444 comma separated lists of numbers). */ 445 446 #define ASM_OUTPUT_LIMITED_STRING(FILE, STR) \ 447 default_elf_asm_output_limited_string ((FILE), (STR)) 448 449 /* The routine used to output sequences of byte values. We use a special 450 version of this for most svr4 targets because doing so makes the 451 generated assembly code more compact (and thus faster to assemble) 452 as well as more readable. Note that if we find subparts of the 453 character sequence which end with NUL (and which are shorter than 454 STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING. */ 455 456 #undef ASM_OUTPUT_ASCII 457 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH) \ 458 default_elf_asm_output_ascii ((FILE), (STR), (LENGTH)) 459 460 /* Allow the use of the -frecord-gcc-switches switch via the 461 elf_record_gcc_switches function defined in varasm.c. */ 462 #undef TARGET_ASM_RECORD_GCC_SWITCHES 463 #define TARGET_ASM_RECORD_GCC_SWITCHES elf_record_gcc_switches 464 465 /* A C statement (sans semicolon) to output to the stdio stream STREAM 466 any text necessary for declaring the name of an external symbol 467 named NAME which is referenced in this compilation but not defined. 468 It is needed to properly support non-default visibility. */ 469 470 #ifndef ASM_OUTPUT_EXTERNAL 471 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \ 472 default_elf_asm_output_external (FILE, DECL, NAME) 473 #endif 474 475 #undef TARGET_LIBC_HAS_FUNCTION 476 #define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function 477