gcc/config/i386/cygming.h

   1 /* Operating system specific defines to be used when targeting GCC for
   2    hosting on Windows32, using a Unix style C library and tools.
   3    Copyright (C) 1995-2024 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 #define DWARF2_DEBUGGING_INFO 1
  22
  23 #define CODEVIEW_DEBUGGING_INFO 1
  24
  25 #undef PREFERRED_DEBUGGING_TYPE
  26 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
  27
  28 #undef TARGET_SEH
  29 #define TARGET_SEH  (TARGET_64BIT_MS_ABI && flag_unwind_tables)
  30
  31 /* Win64 with SEH cannot represent DRAP stack frames.  Disable its use.
  32    Force the use of different mechanisms to allocate aligned local data.  */
  33 #undef MAX_STACK_ALIGNMENT
  34 #define MAX_STACK_ALIGNMENT  (TARGET_SEH ? 128 : MAX_OFILE_ALIGNMENT)
  35
  36 /* 32-bit Windows aligns the stack on a 4-byte boundary but SSE instructions
  37    may require 16-byte alignment.  */
  38 #undef STACK_REALIGN_DEFAULT
  39 #define STACK_REALIGN_DEFAULT TARGET_SSE
  40
  41 /* Support hooks for SEH.  */
  42 #undef  TARGET_ASM_UNWIND_EMIT
  43 #define TARGET_ASM_UNWIND_EMIT  i386_pe_seh_unwind_emit
  44 #undef  TARGET_ASM_UNWIND_EMIT_BEFORE_INSN
  45 #define TARGET_ASM_UNWIND_EMIT_BEFORE_INSN  false
  46 #undef  TARGET_ASM_FUNCTION_END_PROLOGUE
  47 #define TARGET_ASM_FUNCTION_END_PROLOGUE  i386_pe_seh_end_prologue
  48 #undef  TARGET_ASM_EMIT_EXCEPT_PERSONALITY
  49 #define TARGET_ASM_EMIT_EXCEPT_PERSONALITY i386_pe_seh_emit_except_personality
  50 #undef  TARGET_ASM_INIT_SECTIONS
  51 #define TARGET_ASM_INIT_SECTIONS  i386_pe_seh_init_sections
  52 #define SUBTARGET_ASM_UNWIND_INIT  i386_pe_seh_init
  53
  54 #undef DEFAULT_ABI
  55 #define DEFAULT_ABI (TARGET_64BIT ? MS_ABI : SYSV_ABI)
  56
  57 #undef TARGET_PECOFF
  58 #define TARGET_PECOFF 1
  59
  60 #if ! defined (USE_MINGW64_LEADING_UNDERSCORES)
  61 #undef USER_LABEL_PREFIX
  62 #define USER_LABEL_PREFIX (TARGET_64BIT ? "" : "_")
  63
  64 #undef LOCAL_LABEL_PREFIX
  65 #define LOCAL_LABEL_PREFIX (TARGET_64BIT ? "." : "")
  66
  67 #undef ASM_GENERATE_INTERNAL_LABEL
  68 #define ASM_GENERATE_INTERNAL_LABEL(BUF,PREFIX,NUMBER)  \
  69   sprintf ((BUF), "*%s%s%ld", LOCAL_LABEL_PREFIX, \
  70            (PREFIX), (long)(NUMBER))
  71
  72 #undef LPREFIX
  73 #define LPREFIX (TARGET_64BIT ? ".L" : "L")
  74
  75 #endif
  76
  77 #undef DEBUGGER_REGNO
  78 #define DEBUGGER_REGNO(n)                               \
  79   (TARGET_64BIT ? debugger64_register_map[n]                    \
  80    : (dwarf_debuginfo_p ()                              \
  81       ? svr4_debugger_register_map[n] : debugger_register_map[n]))
  82
  83 /* Map gcc register number to DWARF 2 CFA column number. For 32 bit
  84    target, always use the svr4_debugger_register_map for DWARF .eh_frame
  85    even if we don't use DWARF .debug_frame. */
  86 #undef DWARF_FRAME_REGNUM
  87 #define DWARF_FRAME_REGNUM(n)                           \
  88   (TARGET_64BIT ? debugger64_register_map[(n)]          \
  89                 : svr4_debugger_register_map[(n)])
  90
  91 /* The 64-bit MS_ABI changes the set of call-used registers.  */
  92 #undef DWARF_FRAME_REGISTERS
  93 #define DWARF_FRAME_REGISTERS (TARGET_64BIT ? 33 : 17)
  94
  95 /* Use section relative relocations for debugging offsets.  Unlike
  96    other targets that fake this by putting the section VMA at 0, PE
  97    won't allow it.  */
  98 #define ASM_OUTPUT_DWARF_OFFSET(FILE, SIZE, LABEL, OFFSET, SECTION) \
  99   do {                                                          \
 100     switch (SIZE)                                               \
 101       {                                                         \
 102       case 4:                                                   \
 103         fputs ("\t.secrel32\t", FILE);                          \
 104         assemble_name (FILE, LABEL);                            \
 105         if ((OFFSET) != 0)                                      \
 106           fprintf (FILE, "+" HOST_WIDE_INT_PRINT_DEC,           \
 107                    (HOST_WIDE_INT) (OFFSET));                   \
 108         break;                                                  \
 109       case 8:                                                   \
 110         /* This is a hack.  There is no 64-bit section relative \
 111            relocation.  However, the COFF format also does not  \
 112            support 64-bit file offsets; 64-bit applications are \
 113            limited to 32-bits of code+data in any one module.   \
 114            Fake the 64-bit offset by zero-extending it.  */     \
 115         fputs ("\t.secrel32\t", FILE);                          \
 116         assemble_name (FILE, LABEL);                            \
 117         if ((OFFSET) != 0)                                      \
 118           fprintf (FILE, "+" HOST_WIDE_INT_PRINT_DEC,           \
 119                    (HOST_WIDE_INT) (OFFSET));                   \
 120         fputs ("\n\t.long\t0", FILE);                           \
 121         break;                                                  \
 122       default:                                                  \
 123         gcc_unreachable ();                                     \
 124       }                                                         \
 125   } while (0)
 126
 127 #define TARGET_EXECUTABLE_SUFFIX ".exe"
 128
 129 #define TARGET_OS_CPP_BUILTINS()                                        \
 130   do                                                                    \
 131     {                                                                   \
 132         if (!TARGET_64BIT)                                              \
 133           builtin_define ("_X86_=1");                                   \
 134         if (TARGET_SEH)                                                 \
 135           builtin_define ("__SEH__");                           \
 136         builtin_assert ("system=winnt");                                \
 137         builtin_define ("__stdcall=__attribute__((__stdcall__))");      \
 138         builtin_define ("__fastcall=__attribute__((__fastcall__))");    \
 139         builtin_define ("__thiscall=__attribute__((__thiscall__))");    \
 140         builtin_define ("__cdecl=__attribute__((__cdecl__))");          \
 141         if (!flag_iso)                                                  \
 142           {                                                             \
 143             builtin_define ("_stdcall=__attribute__((__stdcall__))");   \
 144             builtin_define ("_fastcall=__attribute__((__fastcall__))"); \
 145             builtin_define ("_thiscall=__attribute__((__thiscall__))"); \
 146             builtin_define ("_cdecl=__attribute__((__cdecl__))");       \
 147           }                                                             \
 148         /* Even though linkonce works with static libs, this is needed  \
 149             to compare typeinfo symbols across dll boundaries.  */      \
 150         builtin_define ("__GXX_MERGED_TYPEINFO_NAMES=0");               \
 151         builtin_define ("__GXX_TYPEINFO_EQUALITY_INLINE=0");            \
 152         EXTRA_OS_CPP_BUILTINS ();                                       \
 153   }                                                                     \
 154   while (0)
 155
 156 /* Get tree.cc to declare a target-specific specialization of
 157    merge_decl_attributes.  */
 158 #define TARGET_DLLIMPORT_DECL_ATTRIBUTES 1
 159
 160 /* This macro defines names of additional specifications to put in the specs
 161    that can be used in various specifications like CC1_SPEC.  Its definition
 162    is an initializer with a subgrouping for each command option.
 163
 164    Each subgrouping contains a string constant, that defines the
 165    specification name, and a string constant that used by the GCC driver
 166    program.
 167
 168    Do not define this macro if it does not need to do anything.  */
 169
 170 #undef  SUBTARGET_EXTRA_SPECS
 171 #define SUBTARGET_EXTRA_SPECS                                           \
 172   { "mingw_include_path", DEFAULT_TARGET_MACHINE }
 173
 174 #undef MATH_LIBRARY
 175 #define MATH_LIBRARY ""
 176
 177 #undef TARGET_LIBC_HAS_FUNCTION
 178 #define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function
 179
 180 #define SIZE_TYPE (TARGET_64BIT ? "long long unsigned int" : "unsigned int")
 181 #define PTRDIFF_TYPE (TARGET_64BIT ? "long long int" : "int")
 182
 183 #define WCHAR_TYPE_SIZE 16
 184 #define WCHAR_TYPE "short unsigned int"
 185
 186 /* Windows64 continues to use a 32-bit long type.  */
 187 #undef LONG_TYPE_SIZE
 188 #define LONG_TYPE_SIZE 32
 189 \f
 190 #define drectve_section() \
 191   (fprintf (asm_out_file, "\t.section .drectve\n"), \
 192    in_section = NULL)
 193
 194 /* Older versions of gas don't handle 'r' as data.
 195    Explicitly set data flag with 'd'.  */
 196 #define READONLY_DATA_SECTION_ASM_OP "\t.section .rdata,\"dr\""
 197
 198 /* Don't allow flag_pic to propagate since gas may produce invalid code
 199    otherwise.  */
 200
 201 #undef  SUBTARGET_OVERRIDE_OPTIONS
 202 #define SUBTARGET_OVERRIDE_OPTIONS                                      \
 203 do {                                                                    \
 204   flag_pic = TARGET_64BIT ? 1 : 0;                                      \
 205 } while (0)
 206
 207 /* Define this macro if references to a symbol must be treated
 208    differently depending on something about the variable or
 209    function named by the symbol (such as what section it is in).
 210
 211    On i386 running Windows NT, modify the assembler name with a suffix
 212    consisting of an atsign (@) followed by string of digits that represents
 213    the number of bytes of arguments passed to the function, if it has the
 214    attribute STDCALL.
 215
 216    In addition, we must mark dll symbols specially. Definitions of
 217    dllexport'd objects install some info in the .drectve section.
 218    References to dllimport'd objects are fetched indirectly via
 219    _imp__.  If both are declared, dllexport overrides.  This is also
 220    needed to implement one-only vtables: they go into their own
 221    section and we need to set DECL_SECTION_NAME so we do that here.
 222    Note that we can be called twice on the same decl.  */
 223
 224 #define SUBTARGET_ENCODE_SECTION_INFO  mingw_pe_encode_section_info
 225
 226 /* Local and global relocs can be placed always into readonly memory
 227    for PE-COFF targets.  */
 228 #undef TARGET_ASM_RELOC_RW_MASK
 229 #define TARGET_ASM_RELOC_RW_MASK i386_pe_reloc_rw_mask
 230
 231 /* Output a common block.  */
 232 #undef ASM_OUTPUT_ALIGNED_DECL_COMMON
 233 #define ASM_OUTPUT_ALIGNED_DECL_COMMON \
 234   i386_pe_asm_output_aligned_decl_common
 235
 236 /* Output the label for an initialized variable.  */
 237 #undef ASM_DECLARE_OBJECT_NAME
 238 #define ASM_DECLARE_OBJECT_NAME(STREAM, NAME, DECL)     \
 239 do {                                                    \
 240   mingw_pe_maybe_record_exported_symbol (DECL, NAME, 1);        \
 241   ASM_OUTPUT_LABEL ((STREAM), (NAME));                  \
 242 } while (0)
 243
 244 /* Output a reference to a label. Fastcall function symbols
 245    keep their '@' prefix, while other symbols are prefixed
 246    with user_label_prefix.  */
 247 #undef ASM_OUTPUT_LABELREF
 248 #define  ASM_OUTPUT_LABELREF(STREAM, NAME)      \
 249 do {                                            \
 250   if ((NAME)[0] != FASTCALL_PREFIX)             \
 251     fputs (user_label_prefix, (STREAM));        \
 252   fputs ((NAME), (STREAM));                     \
 253 } while (0)
 254
 255 /* This does much the same in memory rather than to a stream.  */
 256 #undef TARGET_MANGLE_ASSEMBLER_NAME
 257 #define TARGET_MANGLE_ASSEMBLER_NAME i386_pe_mangle_assembler_name
 258
 259 \f
 260 /* Emit code to check the stack when allocating more than 4000
 261    bytes in one go.  */
 262 #define CHECK_STACK_LIMIT 4000
 263
 264 /* By default, target has a 80387, uses IEEE compatible arithmetic,
 265    returns float values in the 387 and needs stack probes.
 266    We also align doubles to 64-bits for MSVC default compatibility.  */
 267
 268 #undef TARGET_SUBTARGET_DEFAULT
 269 #define TARGET_SUBTARGET_DEFAULT \
 270         (MASK_80387 | MASK_IEEE_FP | MASK_FLOAT_RETURNS \
 271          | MASK_STACK_PROBE | MASK_ALIGN_DOUBLE)
 272
 273 #undef TARGET_SUBTARGET64_DEFAULT
 274 #define TARGET_SUBTARGET64_DEFAULT \
 275         MASK_128BIT_LONG_DOUBLE
 276
 277 /* This is how to output an assembler line
 278    that says to advance the location counter
 279    to a multiple of 2**LOG bytes.  */
 280
 281 #undef ASM_OUTPUT_ALIGN
 282 #define ASM_OUTPUT_ALIGN(FILE,LOG)      \
 283     if ((LOG) != 0) fprintf ((FILE), "\t.align %d\n", 1 << (LOG))
 284
 285 /* Windows uses explicit import from shared libraries.  */
 286 #define MULTIPLE_SYMBOL_SPACES 1
 287
 288 #define TARGET_ASM_UNIQUE_SECTION mingw_pe_unique_section
 289 #define TARGET_ASM_FUNCTION_RODATA_SECTION default_no_function_rodata_section
 290
 291 #define SUPPORTS_ONE_ONLY 1
 292
 293 /* Switch into a generic section.  */
 294 #define TARGET_ASM_NAMED_SECTION  mingw_pe_asm_named_section
 295
 296 /* Select attributes for named sections.  */
 297 #define TARGET_SECTION_TYPE_FLAGS  mingw_pe_section_type_flags
 298
 299 /* Write the extra assembler code needed to declare a function
 300    properly.  */
 301 #undef ASM_DECLARE_FUNCTION_NAME
 302 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
 303   i386_pe_start_function (FILE, NAME, DECL)
 304
 305 /* Write the extra assembler code needed to declare the name of a
 306    cold function partition properly.  */
 307
 308 #undef ASM_DECLARE_COLD_FUNCTION_NAME
 309 #define ASM_DECLARE_COLD_FUNCTION_NAME(FILE, NAME, DECL)        \
 310   do                                                            \
 311     {                                                           \
 312       mingw_pe_declare_function_type (FILE, NAME, 0);           \
 313       i386_pe_seh_cold_init (FILE, NAME);                       \
 314       ASM_OUTPUT_LABEL (FILE, NAME);                            \
 315     }                                                           \
 316   while (0)
 317
 318 #undef ASM_DECLARE_FUNCTION_SIZE
 319 #define ASM_DECLARE_FUNCTION_SIZE(FILE,NAME,DECL) \
 320   i386_pe_end_function (FILE, NAME, DECL)
 321
 322 #undef ASM_DECLARE_COLD_FUNCTION_SIZE
 323 #define ASM_DECLARE_COLD_FUNCTION_SIZE(FILE,NAME,DECL) \
 324   i386_pe_end_cold_function (FILE, NAME, DECL)
 325
 326 /* Add an external function to the list of functions to be declared at
 327    the end of the file.  */
 328 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME)                           \
 329   do                                                                    \
 330     {                                                                   \
 331       if (TREE_CODE (DECL) == FUNCTION_DECL)                            \
 332         i386_pe_record_external_function ((DECL), (NAME));              \
 333     }                                                                   \
 334   while (0)
 335
 336 /* Declare the type properly for any external libcall.  */
 337 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \
 338   mingw_pe_declare_function_type (FILE, XSTR (FUN, 0), 1)
 339
 340 /* This says out to put a global symbol in the BSS section.  */
 341 #undef ASM_OUTPUT_ALIGNED_BSS
 342 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
 343   asm_output_aligned_bss ((FILE), (DECL), (NAME), (SIZE), (ALIGN))
 344
 345 /* Output function declarations at the end of the file.  */
 346 #undef TARGET_ASM_FILE_END
 347 #define TARGET_ASM_FILE_END mingw_pe_file_end
 348
 349 /* Kludge because of missing PE-COFF support for early LTO debug.  */
 350 #undef  TARGET_ASM_LTO_START
 351 #define TARGET_ASM_LTO_START i386_pe_asm_lto_start
 352 #undef  TARGET_ASM_LTO_END
 353 #define TARGET_ASM_LTO_END i386_pe_asm_lto_end
 354
 355 #undef ASM_COMMENT_START
 356 #define ASM_COMMENT_START " #"
 357
 358 #ifndef DWARF2_UNWIND_INFO
 359 /* If configured with --disable-sjlj-exceptions, use DWARF2 for 32-bit
 360    mode else default to SJLJ.  64-bit code uses SEH unless you request
 361    SJLJ.  */
 362 #if  (defined (CONFIG_SJLJ_EXCEPTIONS) && !CONFIG_SJLJ_EXCEPTIONS)
 363 /* The logic of this #if must be kept synchronised with the logic
 364    for selecting the tmake_eh_file fragment in libgcc/config.host.  */
 365 #define DWARF2_UNWIND_INFO 1
 366 #else
 367 #define DWARF2_UNWIND_INFO 0
 368 #endif
 369 #endif
 370
 371 #undef PROFILE_HOOK
 372 #define PROFILE_HOOK(LABEL)                                             \
 373   if (MAIN_NAME_P (DECL_NAME (current_function_decl)))                  \
 374     {                                                                   \
 375       emit_call_insn (gen_rtx_CALL (VOIDmode,                           \
 376         gen_rtx_MEM (FUNCTION_MODE,                                     \
 377                      gen_rtx_SYMBOL_REF (Pmode, "_monstartup")),        \
 378         const0_rtx));                                                   \
 379     }
 380
 381 /* For Win32 ABI compatibility */
 382 #undef DEFAULT_PCC_STRUCT_RETURN
 383 #define DEFAULT_PCC_STRUCT_RETURN 0
 384
 385 /* MSVC returns aggregate types of up to 8 bytes via registers.
 386    See i386.cc:ix86_return_in_memory.  */
 387 #undef MS_AGGREGATE_RETURN
 388 #define MS_AGGREGATE_RETURN 1
 389
 390 /* Biggest alignment supported by the object file format of this
 391    machine.  Use this macro to limit the alignment which can be
 392    specified using the `__attribute__ ((aligned (N)))' construct.  If
 393    not defined, the default value is `BIGGEST_ALIGNMENT'.  */
 394 /* IMAGE_SCN_ALIGN_8192BYTES is the largest section alignment flag
 395    specified in the PECOFF60 spec.  Native MS compiler also limits
 396    user-specified alignment to 8192 bytes.  */
 397 #undef MAX_OFILE_ALIGNMENT
 398 #define MAX_OFILE_ALIGNMENT (8192 * 8)
 399
 400 /* BIGGEST_FIELD_ALIGNMENT macro is used directly by libobjc, There, we
 401    align internal doubles in structures on dword boundaries. Otherwise,
 402    support vector modes using ADJUST_FIELD_ALIGN, defined in i386.h.  */
 403 #ifdef IN_TARGET_LIBS
 404 #undef  BIGGEST_FIELD_ALIGNMENT
 405 #define BIGGEST_FIELD_ALIGNMENT 64
 406 #endif
 407
 408 /* Enable alias attribute support.  */
 409 #ifndef SET_ASM_OP
 410 #define SET_ASM_OP "\t.set\t"
 411 #endif
 412
 413 /* This implements the `alias' attribute, keeping any stdcall or
 414    fastcall decoration.  */
 415 #undef  ASM_OUTPUT_DEF_FROM_DECLS
 416 #define ASM_OUTPUT_DEF_FROM_DECLS(STREAM, DECL, TARGET)                 \
 417   do                                                                    \
 418     {                                                                   \
 419       const char *alias                                                 \
 420         = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL));              \
 421       mingw_pe_maybe_record_exported_symbol (DECL, alias, 0);           \
 422       if (TREE_CODE (DECL) == FUNCTION_DECL)                            \
 423         mingw_pe_declare_function_type (STREAM, alias,                  \
 424                                        TREE_PUBLIC (DECL));             \
 425       ASM_OUTPUT_DEF (STREAM, alias, IDENTIFIER_POINTER (TARGET));      \
 426     } while (0)
 427
 428 /* GNU as supports weak symbols on PECOFF. */
 429 #ifdef HAVE_GAS_WEAK
 430 #define ASM_WEAKEN_LABEL(FILE, NAME)  \
 431   do                                  \
 432     {                                 \
 433       fputs ("\t.weak\t", (FILE));    \
 434       assemble_name ((FILE), (NAME)); \
 435       fputc ('\n', (FILE));           \
 436     }                                 \
 437   while (0)
 438
 439 #endif /* HAVE_GAS_WEAK */
 440
 441 /* Decide whether it is safe to use a local alias for a virtual function
 442    when constructing thunks.  */
 443 #undef TARGET_USE_LOCAL_THUNK_ALIAS_P
 444 #define TARGET_USE_LOCAL_THUNK_ALIAS_P(DECL) (!DECL_ONE_ONLY (DECL))
 445
 446 #define SUBTARGET_ATTRIBUTE_TABLE \
 447   { "selectany", 0, 0, true, false, false, false, \
 448     mingw_handle_selectany_attribute, NULL }
 449   /* { name, min_len, max_len, decl_req, type_req, fn_type_req,
 450        affects_type_identity, handler, exclude } */
 451
 452 /*  mcount() does not need a counter variable.  */
 453 #undef NO_PROFILE_COUNTERS
 454 #define NO_PROFILE_COUNTERS 1
 455
 456 #define TARGET_VALID_DLLIMPORT_ATTRIBUTE_P mingw_pe_valid_dllimport_attribute_p
 457 #define TARGET_CXX_ADJUST_CLASS_AT_DEFINITION i386_pe_adjust_class_at_definition
 458 #define SUBTARGET_MANGLE_DECL_ASSEMBLER_NAME i386_pe_mangle_decl_assembler_name
 459
 460 #undef TARGET_ASM_ASSEMBLE_VISIBILITY
 461 #define TARGET_ASM_ASSEMBLE_VISIBILITY i386_pe_assemble_visibility
 462
 463 #undef SUB_TARGET_RECORD_STUB
 464 #define SUB_TARGET_RECORD_STUB mingw_pe_record_stub
 465
 466 /* Static stack checking is supported by means of probes.  */
 467 #define STACK_CHECK_STATIC_BUILTIN 1
 468
 469 #ifndef HAVE_GAS_ALIGNED_COMM
 470 # define HAVE_GAS_ALIGNED_COMM 0
 471 #endif
 472
 473 #define PE_COFF_LEGITIMIZE_EXTERN_DECL \
 474   (ix86_cmodel == CM_LARGE_PIC || ix86_cmodel == CM_MEDIUM_PIC)
 475
 476 #define HAVE_64BIT_POINTERS TARGET_64BIT_DEFAULT