gcc/config/elfos.h

   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
   4    Free Software Foundation, Inc.
   5    Based on svr4.h contributed by Ron Guilmette (rfg@netcom.com).
   6
   7 This file is part of GNU CC.
   8
   9 GNU CC 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 2, or (at your option)
  12 any later version.
  13
  14 GNU CC 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 You should have received a copy of the GNU General Public License
  20 along with GNU CC; see the file COPYING.  If not, write to
  21 the Free Software Foundation, 59 Temple Place - Suite 330,
  22 Boston, MA 02111-1307, USA.  */
  23
  24 /* The prefix to add to user-visible assembler symbols.
  25
  26    For ELF systems the convention is *not* to prepend a leading
  27    underscore onto user-level symbol names.  */
  28
  29 #undef  USER_LABEL_PREFIX
  30 #define USER_LABEL_PREFIX ""
  31
  32 /* Biggest alignment supported by the object file format of this
  33    machine.  Use this macro to limit the alignment which can be
  34    specified using the `__attribute__ ((aligned (N)))' construct.  If
  35    not defined, the default value is `BIGGEST_ALIGNMENT'.  */
  36 #ifndef MAX_OFILE_ALIGNMENT
  37 #define MAX_OFILE_ALIGNMENT (32768 * 8)
  38 #endif
  39
  40 #undef  ENDFILE_SPEC
  41 #define ENDFILE_SPEC "crtend.o%s"
  42
  43 #undef  STARTFILE_SPEC
  44 #define STARTFILE_SPEC "%{!shared: \
  45                          %{!symbolic: \
  46                           %{pg:gcrt0.o%s}%{!pg:%{p:mcrt0.o%s}%{!p:crt0.o%s}}}}\
  47                         crtbegin.o%s"
  48
  49 /* Use periods rather than dollar signs in special g++ assembler names.  */
  50
  51 #define NO_DOLLAR_IN_LABEL
  52
  53 /* Writing `int' for a bitfield forces int alignment for the structure.  */
  54
  55 #define PCC_BITFIELD_TYPE_MATTERS 1
  56
  57 /* Implicit library calls should use memcpy, not bcopy, etc.  */
  58
  59 #define TARGET_MEM_FUNCTIONS
  60
  61 /* Handle #pragma weak and #pragma pack.  */
  62
  63 #define HANDLE_SYSV_PRAGMA
  64
  65 /* System V Release 4 uses DWARF debugging info.  */
  66
  67 #ifndef DWARF_DEBUGGING_INFO
  68 #define DWARF_DEBUGGING_INFO 1
  69 #endif
  70
  71 /* All ELF targets can support DWARF-2.  */
  72
  73 #ifndef DWARF2_DEBUGGING_INFO
  74 #define DWARF2_DEBUGGING_INFO 1
  75 #endif
  76
  77 /* Also allow them to support STABS debugging.  */
  78
  79 #include "dbxelf.h"
  80
  81 /* The GNU tools operate better with stabs.  Since we don't have
  82    any native tools to be compatible with, default to stabs.  */
  83
  84 #ifndef PREFERRED_DEBUGGING_TYPE
  85 #define PREFERRED_DEBUGGING_TYPE DBX_DEBUG
  86 #endif
  87
  88 /* All SVR4 targets use the ELF object file format.  */
  89 #define OBJECT_FORMAT_ELF
  90
  91
  92 /* Output #ident as a .ident.  */
  93
  94 #define ASM_OUTPUT_IDENT(FILE, NAME) \
  95   fprintf (FILE, "%s\"%s\"\n", IDENT_ASM_OP, NAME);
  96
  97 /* Attach a special .ident directive to the end of the file to identify
  98    the version of GCC which compiled this code.  The format of the
  99    .ident string is patterned after the ones produced by native svr4
 100    C compilers.  */
 101
 102 #define IDENT_ASM_OP "\t.ident\t"
 103
 104 #undef ASM_FILE_END
 105 #define ASM_FILE_END(FILE)                              \
 106   do                                                    \
 107     {                                                   \
 108       if (!flag_no_ident)                               \
 109         fprintf ((FILE), "%s\"GCC: (GNU) %s\"\n",       \
 110                  IDENT_ASM_OP, version_string);         \
 111     }                                                   \
 112   while (0)
 113
 114 #undef  ASM_BYTE_OP
 115 #define ASM_BYTE_OP     "\t.byte\t"
 116
 117 #undef  SET_ASM_OP
 118 #define SET_ASM_OP      "\t.set\t"
 119
 120 /* This is how to begin an assembly language file.  Most svr4 assemblers want
 121    at least a .file directive to come first, and some want to see a .version
 122    directive come right after that.  Here we just establish a default
 123    which generates only the .file directive.  If you need a .version
 124    directive for any specific target, you should override this definition
 125    in the target-specific file which includes this one.  */
 126
 127 #undef ASM_FILE_START
 128 #define ASM_FILE_START(FILE)                            \
 129   output_file_directive ((FILE), main_input_filename)
 130
 131 /* This is how to allocate empty space in some section.  The .zero
 132    pseudo-op is used for this on most svr4 assemblers.  */
 133
 134 #define SKIP_ASM_OP     "\t.zero\t"
 135
 136 #undef  ASM_OUTPUT_SKIP
 137 #define ASM_OUTPUT_SKIP(FILE, SIZE) \
 138   fprintf (FILE, "%s%u\n", SKIP_ASM_OP, (SIZE))
 139
 140 /* This is how to output an internal numbered label where
 141    PREFIX is the class of label and NUM is the number within the class.
 142
 143    For most svr4 systems, the convention is that any symbol which begins
 144    with a period is not put into the linker symbol table by the assembler.  */
 145
 146 #undef  ASM_OUTPUT_INTERNAL_LABEL
 147 #define ASM_OUTPUT_INTERNAL_LABEL(FILE, PREFIX, NUM)    \
 148   do                                                    \
 149     {                                                   \
 150       fprintf (FILE, ".%s%d:\n", PREFIX, NUM);          \
 151     }                                                   \
 152   while (0)
 153
 154 /* This is how to store into the string LABEL
 155    the symbol_ref name of an internal numbered label where
 156    PREFIX is the class of label and NUM is the number within the class.
 157    This is suitable for output with `assemble_name'.
 158
 159    For most svr4 systems, the convention is that any symbol which begins
 160    with a period is not put into the linker symbol table by the assembler.  */
 161
 162 #undef  ASM_GENERATE_INTERNAL_LABEL
 163 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM)         \
 164   do                                                            \
 165     {                                                           \
 166       sprintf (LABEL, "*.%s%u", PREFIX, (unsigned) (NUM));      \
 167     }                                                           \
 168   while (0)
 169
 170 /* Output the label which precedes a jumptable.  Note that for all svr4
 171    systems where we actually generate jumptables (which is to say every
 172    svr4 target except i386, where we use casesi instead) we put the jump-
 173    tables into the .rodata section and since other stuff could have been
 174    put into the .rodata section prior to any given jumptable, we have to
 175    make sure that the location counter for the .rodata section gets pro-
 176    perly re-aligned prior to the actual beginning of the jump table.  */
 177
 178 #define ALIGN_ASM_OP "\t.align\t"
 179
 180 #ifndef ASM_OUTPUT_BEFORE_CASE_LABEL
 181 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) \
 182   ASM_OUTPUT_ALIGN ((FILE), 2);
 183 #endif
 184
 185 #undef  ASM_OUTPUT_CASE_LABEL
 186 #define ASM_OUTPUT_CASE_LABEL(FILE, PREFIX, NUM, JUMPTABLE)             \
 187   do                                                                    \
 188     {                                                                   \
 189       ASM_OUTPUT_BEFORE_CASE_LABEL (FILE, PREFIX, NUM, JUMPTABLE)       \
 190         ASM_OUTPUT_INTERNAL_LABEL (FILE, PREFIX, NUM);                  \
 191     }                                                                   \
 192   while (0)
 193
 194 /* The standard SVR4 assembler seems to require that certain builtin
 195    library routines (e.g. .udiv) be explicitly declared as .globl
 196    in each assembly file where they are referenced.  */
 197
 198 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN)  \
 199   ASM_GLOBALIZE_LABEL (FILE, XSTR (FUN, 0))
 200
 201 /* This says how to output assembler code to declare an
 202    uninitialized external linkage data object.  Under SVR4,
 203    the linker seems to want the alignment of data objects
 204    to depend on their types.  We do exactly that here.  */
 205
 206 #define COMMON_ASM_OP   "\t.comm\t"
 207
 208 #undef  ASM_OUTPUT_ALIGNED_COMMON
 209 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN)              \
 210   do                                                                    \
 211     {                                                                   \
 212       fprintf ((FILE), "%s", COMMON_ASM_OP);                            \
 213       assemble_name ((FILE), (NAME));                                   \
 214       fprintf ((FILE), ",%u,%u\n", (SIZE), (ALIGN) / BITS_PER_UNIT);    \
 215     }                                                                   \
 216   while (0)
 217
 218 /* This says how to output assembler code to declare an
 219    uninitialized internal linkage data object.  Under SVR4,
 220    the linker seems to want the alignment of data objects
 221    to depend on their types.  We do exactly that here.  */
 222
 223 #define LOCAL_ASM_OP    "\t.local\t"
 224
 225 #undef  ASM_OUTPUT_ALIGNED_LOCAL
 226 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN)       \
 227   do                                                            \
 228     {                                                           \
 229       fprintf ((FILE), "%s", LOCAL_ASM_OP);                     \
 230       assemble_name ((FILE), (NAME));                           \
 231       fprintf ((FILE), "\n");                                   \
 232       ASM_OUTPUT_ALIGNED_COMMON (FILE, NAME, SIZE, ALIGN);      \
 233     }                                                           \
 234   while (0)
 235
 236 /* This is the pseudo-op used to generate a reference to a specific
 237    symbol in some section.  It is only used in machine-specific
 238    configuration files, typically only in ASM_OUTPUT_CONSTRUCTOR and
 239    ASM_OUTPUT_DESTRUCTOR.  This is the same for all known svr4
 240    assemblers, except those in targets that don't use 32-bit pointers.
 241    Those should override INT_ASM_OP.  Yes, the name of the macro is
 242    misleading.  */
 243
 244 #ifndef INT_ASM_OP
 245 #define INT_ASM_OP              "\t.long\t"
 246 #endif
 247
 248 /* This is the pseudo-op used to generate a contiguous sequence of byte
 249    values from a double-quoted string WITHOUT HAVING A TERMINATING NUL
 250    AUTOMATICALLY APPENDED.  This is the same for most svr4 assemblers.  */
 251
 252 #undef  ASCII_DATA_ASM_OP
 253 #define ASCII_DATA_ASM_OP       "\t.ascii\t"
 254
 255 /* Support const sections and the ctors and dtors sections for g++.
 256    Note that there appears to be two different ways to support const
 257    sections at the moment.  You can either #define the symbol
 258    READONLY_DATA_SECTION (giving it some code which switches to the
 259    readonly data section) or else you can #define the symbols
 260    EXTRA_SECTIONS, EXTRA_SECTION_FUNCTIONS, SELECT_SECTION, and
 261    SELECT_RTX_SECTION.  We do both here just to be on the safe side.  */
 262
 263 #define USE_CONST_SECTION       1
 264
 265 #define CONST_SECTION_ASM_OP    "\t.section\t.rodata"
 266
 267 /* Define the pseudo-ops used to switch to the .ctors and .dtors sections.
 268
 269    Note that we want to give these sections the SHF_WRITE attribute
 270    because these sections will actually contain data (i.e. tables of
 271    addresses of functions in the current root executable or shared library
 272    file) and, in the case of a shared library, the relocatable addresses
 273    will have to be properly resolved/relocated (and then written into) by
 274    the dynamic linker when it actually attaches the given shared library
 275    to the executing process.  (Note that on SVR4, you may wish to use the
 276    `-z text' option to the ELF linker, when building a shared library, as
 277    an additional check that you are doing everything right.  But if you do
 278    use the `-z text' option when building a shared library, you will get
 279    errors unless the .ctors and .dtors sections are marked as writable
 280    via the SHF_WRITE attribute.)  */
 281
 282 #define CTORS_SECTION_ASM_OP    "\t.section\t.ctors,\"aw\""
 283 #define DTORS_SECTION_ASM_OP    "\t.section\t.dtors,\"aw\""
 284
 285 /* On svr4, we *do* have support for the .init and .fini sections, and we
 286    can put stuff in there to be executed before and after `main'.  We let
 287    crtstuff.c and other files know this by defining the following symbols.
 288    The definitions say how to change sections to the .init and .fini
 289    sections.  This is the same for all known svr4 assemblers.  */
 290
 291 #define INIT_SECTION_ASM_OP     "\t.section\t.init"
 292 #define FINI_SECTION_ASM_OP     "\t.section\t.fini"
 293
 294 /* A default list of other sections which we might be "in" at any given
 295    time.  For targets that use additional sections (e.g. .tdesc) you
 296    should override this definition in the target-specific file which
 297    includes this file.  */
 298
 299 #undef  EXTRA_SECTIONS
 300 #define EXTRA_SECTIONS in_const, in_ctors, in_dtors
 301
 302 /* A default list of extra section function definitions.  For targets
 303    that use additional sections (e.g. .tdesc) you should override this
 304    definition in the target-specific file which includes this file.  */
 305
 306 #undef  EXTRA_SECTION_FUNCTIONS
 307 #define EXTRA_SECTION_FUNCTIONS         \
 308   CONST_SECTION_FUNCTION                \
 309   CTORS_SECTION_FUNCTION                \
 310   DTORS_SECTION_FUNCTION
 311
 312 #define READONLY_DATA_SECTION() const_section ()
 313
 314 #define CONST_SECTION_FUNCTION                                  \
 315 void                                                            \
 316 const_section ()                                                \
 317 {                                                               \
 318   if (!USE_CONST_SECTION)                                       \
 319     text_section ();                                            \
 320   else if (in_section != in_const)                              \
 321     {                                                           \
 322       fprintf (asm_out_file, "%s\n", CONST_SECTION_ASM_OP);     \
 323       in_section = in_const;                                    \
 324     }                                                           \
 325 }
 326
 327 #define CTORS_SECTION_FUNCTION                                  \
 328 void                                                            \
 329 ctors_section ()                                                \
 330 {                                                               \
 331   if (in_section != in_ctors)                                   \
 332     {                                                           \
 333       fprintf (asm_out_file, "%s\n", CTORS_SECTION_ASM_OP);     \
 334       in_section = in_ctors;                                    \
 335     }                                                           \
 336 }
 337
 338 #define DTORS_SECTION_FUNCTION                                  \
 339 void                                                            \
 340 dtors_section ()                                                \
 341 {                                                               \
 342   if (in_section != in_dtors)                                   \
 343     {                                                           \
 344       fprintf (asm_out_file, "%s\n", DTORS_SECTION_ASM_OP);     \
 345       in_section = in_dtors;                                    \
 346     }                                                           \
 347 }
 348
 349 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
 350
 351 #define UNIQUE_SECTION_P(DECL)   (DECL_ONE_ONLY (DECL))
 352
 353 #define UNIQUE_SECTION(DECL, RELOC)                             \
 354   do                                                            \
 355     {                                                           \
 356       int len;                                                  \
 357       int sec;                                                  \
 358       const char *name;                                         \
 359       char *string;                                             \
 360       const char *prefix;                                       \
 361       static const char *prefixes[/*4*/3][2] =                  \
 362       {                                                         \
 363         { ".text.",   ".gnu.linkonce.t." },                     \
 364         { ".rodata.", ".gnu.linkonce.r." },                     \
 365         { ".data.",   ".gnu.linkonce.d." }                      \
 366         /* Do not generate unique sections for uninitialised    \
 367            data since we do not have support for this in the    \
 368            linker scripts yet...                                \
 369         ,{ ".bss.",    ".gnu.linkonce.b." }  */                 \
 370       };                                                        \
 371                                                                 \
 372       if (TREE_CODE (DECL) == FUNCTION_DECL)                    \
 373         sec = 0;                                                \
 374   /*  else if (DECL_INITIAL (DECL) == 0                         \
 375                || DECL_INITIAL (DECL) == error_mark_node)       \
 376         sec =  3; */                                            \
 377       else if (DECL_READONLY_SECTION (DECL, RELOC))             \
 378         sec = 1;                                                \
 379       else                                                      \
 380         sec = 2;                                                \
 381                                                                 \
 382       name   = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL)); \
 383       /* Strip off any encoding in name.  */                    \
 384       STRIP_NAME_ENCODING (name, name);                         \
 385       prefix = prefixes[sec][DECL_ONE_ONLY(DECL)];              \
 386       len    = strlen (name) + strlen (prefix);                 \
 387       string = alloca (len + 1);                                \
 388                                                                 \
 389       sprintf (string, "%s%s", prefix, name);                   \
 390                                                                 \
 391       DECL_SECTION_NAME (DECL) = build_string (len, string);    \
 392     }                                                           \
 393   while (0)
 394
 395 /* A C statement (sans semicolon) to output an
 396    element in the table of global constructors.  */
 397 #define ASM_OUTPUT_CONSTRUCTOR(FILE, NAME)                      \
 398   do                                                            \
 399     {                                                           \
 400       ctors_section ();                                         \
 401       fprintf (FILE, "%s", INT_ASM_OP);                         \
 402       assemble_name (FILE, NAME);                               \
 403       fprintf (FILE, "\n");                                     \
 404     }                                                           \
 405   while (0)
 406
 407 /* A C statement (sans semicolon) to output an
 408    element in the table of global destructors.  */
 409 #define ASM_OUTPUT_DESTRUCTOR(FILE,NAME)                        \
 410   do                                                            \
 411     {                                                           \
 412       dtors_section ();                                         \
 413       fprintf (FILE, "%s", INT_ASM_OP);                         \
 414       assemble_name (FILE, NAME);                               \
 415       fprintf (FILE, "\n");                                     \
 416     }                                                           \
 417   while (0)
 418
 419 /* Switch into a generic section.
 420
 421    We make the section read-only and executable for a function decl,
 422    read-only for a const data decl, and writable for a non-const data decl.
 423
 424    If the section has already been defined, we must not
 425    emit the attributes here. The SVR4 assembler does not
 426    recognize section redefinitions.
 427    If DECL is NULL, no attributes are emitted.  */
 428
 429 #define ASM_OUTPUT_SECTION_NAME(FILE, DECL, NAME, RELOC)                \
 430   do                                                                    \
 431     {                                                                   \
 432       static htab_t htab;                                               \
 433                                                                         \
 434       struct section_info                                               \
 435       {                                                                 \
 436         enum sect_enum {SECT_RW, SECT_RO, SECT_EXEC} type;              \
 437       };                                                                \
 438                                                                         \
 439       struct section_info *s;                                           \
 440       const char *mode;                                                 \
 441       enum sect_enum type;                                              \
 442       PTR* slot;                                                        \
 443                                                                         \
 444       /* The names we put in the hashtable will always be the unique    \
 445          versions gived to us by the stringtable, so we can just use    \
 446          their addresses as the keys.  */                               \
 447       if (!htab)                                                        \
 448         htab = htab_create (31,                                         \
 449                             htab_hash_pointer,                          \
 450                             htab_eq_pointer,                            \
 451                             NULL);                                      \
 452                                                                         \
 453       if (DECL && TREE_CODE (DECL) == FUNCTION_DECL)                    \
 454         type = SECT_EXEC, mode = "ax";                                  \
 455       else if (DECL && DECL_READONLY_SECTION (DECL, RELOC))             \
 456         type = SECT_RO, mode = "a";                                     \
 457       else                                                              \
 458         type = SECT_RW, mode = "aw";                                    \
 459                                                                         \
 460                                                                         \
 461       /* See if we already have an entry for this section.  */          \
 462       slot = htab_find_slot (htab, NAME, INSERT);                       \
 463       if (!*slot)                                                       \
 464         {                                                               \
 465           s = (struct section_info *) xmalloc (sizeof (* s));           \
 466           s->type = type;                                               \
 467           *slot = s;                                                    \
 468           fprintf (FILE, "\t.section\t%s,\"%s\",@progbits\n",           \
 469                    NAME, mode);                                         \
 470         }                                                               \
 471       else                                                              \
 472         {                                                               \
 473           s = (struct section_info *) *slot;                            \
 474           if (DECL && s->type != type)                                  \
 475             error_with_decl (DECL,                                      \
 476                              "%s causes a section type conflict");      \
 477                                                                         \
 478           fprintf (FILE, "\t.section\t%s\n", NAME);                     \
 479         }                                                               \
 480     }                                                                   \
 481   while (0)
 482
 483 /* A C statement or statements to switch to the appropriate
 484    section for output of RTX in mode MODE.  RTX is some kind
 485    of constant in RTL.  The argument MODE is redundant except
 486    in the case of a `const_int' rtx.  Currently, these always
 487    go into the const section.  */
 488
 489 #undef  SELECT_RTX_SECTION
 490 #define SELECT_RTX_SECTION(MODE, RTX) const_section ()
 491
 492 /* A C statement or statements to switch to the appropriate
 493    section for output of DECL.  DECL is either a `VAR_DECL' node
 494    or a constant of some sort.  RELOC indicates whether forming
 495    the initial value of DECL requires link-time relocations.  */
 496
 497 #undef SELECT_SECTION
 498 #define SELECT_SECTION(DECL, RELOC)                             \
 499 {                                                               \
 500   if (TREE_CODE (DECL) == STRING_CST)                           \
 501     {                                                           \
 502       if (! flag_writable_strings)                              \
 503         const_section ();                                       \
 504       else                                                      \
 505         data_section ();                                        \
 506     }                                                           \
 507   else if (TREE_CODE (DECL) == VAR_DECL)                        \
 508     {                                                           \
 509       if ((flag_pic && RELOC)                                   \
 510           || !TREE_READONLY (DECL) || TREE_SIDE_EFFECTS (DECL)  \
 511           || !DECL_INITIAL (DECL)                               \
 512           || (DECL_INITIAL (DECL) != error_mark_node            \
 513               && !TREE_CONSTANT (DECL_INITIAL (DECL))))         \
 514         data_section ();                                        \
 515       else                                                      \
 516         const_section ();                                       \
 517     }                                                           \
 518   else if (TREE_CODE (DECL) == CONSTRUCTOR)                     \
 519     {                                                           \
 520       if ((flag_pic && RELOC)                                   \
 521           || !TREE_READONLY (DECL) || TREE_SIDE_EFFECTS (DECL)  \
 522           || ! TREE_CONSTANT (DECL))                            \
 523         data_section ();                                        \
 524       else                                                      \
 525         const_section ();                                       \
 526     }                                                           \
 527   else                                                          \
 528     const_section ();                                           \
 529 }
 530
 531 /* Define the strings used for the special svr4 .type and .size directives.
 532    These strings generally do not vary from one system running svr4 to
 533    another, but if a given system (e.g. m88k running svr) needs to use
 534    different pseudo-op names for these, they may be overridden in the
 535    file which includes this one.  */
 536
 537 #define TYPE_ASM_OP     "\t.type\t"
 538 #define SIZE_ASM_OP     "\t.size\t"
 539
 540 /* This is how we tell the assembler that a symbol is weak.  */
 541
 542 #define ASM_WEAKEN_LABEL(FILE, NAME)    \
 543   do                                    \
 544     {                                   \
 545       fputs ("\t.weak\t", (FILE));      \
 546       assemble_name ((FILE), (NAME));   \
 547       fputc ('\n', (FILE));             \
 548     }                                   \
 549   while (0)
 550
 551 /* The following macro defines the format used to output the second
 552    operand of the .type assembler directive.  Different svr4 assemblers
 553    expect various different forms for this operand.  The one given here
 554    is just a default.  You may need to override it in your machine-
 555    specific tm.h file (depending upon the particulars of your assembler).  */
 556
 557 #define TYPE_OPERAND_FMT        "@%s"
 558
 559 /* Write the extra assembler code needed to declare a function's result.
 560    Most svr4 assemblers don't require any special declaration of the
 561    result value, but there are exceptions.  */
 562
 563 #ifndef ASM_DECLARE_RESULT
 564 #define ASM_DECLARE_RESULT(FILE, RESULT)
 565 #endif
 566
 567 /* These macros generate the special .type and .size directives which
 568    are used to set the corresponding fields of the linker symbol table
 569    entries in an ELF object file under SVR4.  These macros also output
 570    the starting labels for the relevant functions/objects.  */
 571
 572 /* Write the extra assembler code needed to declare a function properly.
 573    Some svr4 assemblers need to also have something extra said about the
 574    function's return value.  We allow for that here.  */
 575
 576 #ifndef ASM_DECLARE_FUNCTION_NAME
 577 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL)     \
 578   do                                                    \
 579     {                                                   \
 580       fprintf (FILE, "%s", TYPE_ASM_OP);                \
 581       assemble_name (FILE, NAME);                       \
 582       putc (',', FILE);                                 \
 583       fprintf (FILE, TYPE_OPERAND_FMT, "function");     \
 584       putc ('\n', FILE);                                \
 585                                                         \
 586       ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));    \
 587       ASM_OUTPUT_LABEL(FILE, NAME);                     \
 588     }                                                   \
 589   while (0)
 590 #endif
 591
 592 /* Write the extra assembler code needed to declare an object properly.  */
 593
 594 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)               \
 595   do                                                            \
 596     {                                                           \
 597       fprintf (FILE, "%s", TYPE_ASM_OP);                        \
 598       assemble_name (FILE, NAME);                               \
 599       putc (',', FILE);                                         \
 600       fprintf (FILE, TYPE_OPERAND_FMT, "object");               \
 601       putc ('\n', FILE);                                        \
 602                                                                 \
 603       size_directive_output = 0;                                \
 604                                                                 \
 605       if (!flag_inhibit_size_directive                          \
 606           && (DECL) && DECL_SIZE (DECL))                        \
 607         {                                                       \
 608           size_directive_output = 1;                            \
 609           fprintf (FILE, "%s", SIZE_ASM_OP);                    \
 610           assemble_name (FILE, NAME);                           \
 611           putc (',', FILE);                                     \
 612           fprintf (FILE, HOST_WIDE_INT_PRINT_DEC,               \
 613                    int_size_in_bytes (TREE_TYPE (DECL)));       \
 614           fputc ('\n', FILE);                                   \
 615         }                                                       \
 616                                                                 \
 617       ASM_OUTPUT_LABEL (FILE, NAME);                            \
 618     }                                                           \
 619   while (0)
 620
 621 /* Output the size directive for a decl in rest_of_decl_compilation
 622    in the case where we did not do so before the initializer.
 623    Once we find the error_mark_node, we know that the value of
 624    size_directive_output was set
 625    by ASM_DECLARE_OBJECT_NAME when it was run for the same decl.  */
 626
 627 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)\
 628   do                                                            \
 629     {                                                           \
 630       const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);   \
 631                                                                 \
 632       if (!flag_inhibit_size_directive                          \
 633           && DECL_SIZE (DECL)                                   \
 634           && ! AT_END && TOP_LEVEL                              \
 635           && DECL_INITIAL (DECL) == error_mark_node             \
 636           && !size_directive_output)                            \
 637         {                                                       \
 638           size_directive_output = 1;                            \
 639           fprintf (FILE, "%s", SIZE_ASM_OP);                    \
 640           assemble_name (FILE, name);                           \
 641           putc (',', FILE);                                     \
 642           fprintf (FILE, HOST_WIDE_INT_PRINT_DEC,               \
 643                    int_size_in_bytes (TREE_TYPE (DECL)));       \
 644           fputc ('\n', FILE);                                   \
 645         }                                                       \
 646     }                                                           \
 647   while (0)
 648
 649 /* This is how to declare the size of a function.  */
 650 #ifndef ASM_DECLARE_FUNCTION_SIZE
 651 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)            \
 652   do                                                            \
 653     {                                                           \
 654       if (!flag_inhibit_size_directive)                         \
 655         {                                                       \
 656           char label[256];                                      \
 657           static int labelno;                                   \
 658                                                                 \
 659           labelno++;                                            \
 660                                                                 \
 661           ASM_GENERATE_INTERNAL_LABEL (label, "Lfe", labelno);  \
 662           ASM_OUTPUT_INTERNAL_LABEL (FILE, "Lfe", labelno);     \
 663                                                                 \
 664           fprintf (FILE, "%s", SIZE_ASM_OP);                    \
 665           assemble_name (FILE, (FNAME));                        \
 666           fprintf (FILE, ",");                                  \
 667           assemble_name (FILE, label);                          \
 668           fprintf (FILE, "-");                                  \
 669           assemble_name (FILE, (FNAME));                        \
 670           putc ('\n', FILE);                                    \
 671         }                                                       \
 672     }                                                           \
 673   while (0)
 674 #endif
 675
 676 /* A table of bytes codes used by the ASM_OUTPUT_ASCII and
 677    ASM_OUTPUT_LIMITED_STRING macros.  Each byte in the table
 678    corresponds to a particular byte value [0..255].  For any
 679    given byte value, if the value in the corresponding table
 680    position is zero, the given character can be output directly.
 681    If the table value is 1, the byte must be output as a \ooo
 682    octal escape.  If the tables value is anything else, then the
 683    byte value should be output as a \ followed by the value
 684    in the table.  Note that we can use standard UN*X escape
 685    sequences for many control characters, but we don't use
 686    \a to represent BEL because some svr4 assemblers (e.g. on
 687    the i386) don't know about that.  Also, we don't use \v
 688    since some versions of gas, such as 2.2 did not accept it.  */
 689
 690 #define ESCAPES \
 691 "\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\
 692 \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\
 693 \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\
 694 \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\
 695 \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\
 696 \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\
 697 \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\
 698 \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"
 699
 700 /* Some svr4 assemblers have a limit on the number of characters which
 701    can appear in the operand of a .string directive.  If your assembler
 702    has such a limitation, you should define STRING_LIMIT to reflect that
 703    limit.  Note that at least some svr4 assemblers have a limit on the
 704    actual number of bytes in the double-quoted string, and that they
 705    count each character in an escape sequence as one byte.  Thus, an
 706    escape sequence like \377 would count as four bytes.
 707
 708    If your target assembler doesn't support the .string directive, you
 709    should define this to zero.
 710 */
 711
 712 #define STRING_LIMIT    ((unsigned) 256)
 713
 714 #define STRING_ASM_OP   "\t.string\t"
 715
 716 /* The routine used to output NUL terminated strings.  We use a special
 717    version of this for most svr4 targets because doing so makes the
 718    generated assembly code more compact (and thus faster to assemble)
 719    as well as more readable, especially for targets like the i386
 720    (where the only alternative is to output character sequences as
 721    comma separated lists of numbers).   */
 722
 723 #define ASM_OUTPUT_LIMITED_STRING(FILE, STR)            \
 724   do                                                    \
 725     {                                                   \
 726       register const unsigned char *_limited_str =      \
 727         (const unsigned char *) (STR);                  \
 728       register unsigned ch;                             \
 729                                                         \
 730       fprintf ((FILE), "%s\"", STRING_ASM_OP);          \
 731                                                         \
 732       for (; (ch = *_limited_str); _limited_str++)      \
 733         {                                               \
 734           register int escape;                          \
 735                                                         \
 736           switch (escape = ESCAPES[ch])                 \
 737             {                                           \
 738             case 0:                                     \
 739               putc (ch, (FILE));                        \
 740               break;                                    \
 741             case 1:                                     \
 742               fprintf ((FILE), "\\%03o", ch);           \
 743               break;                                    \
 744             default:                                    \
 745               putc ('\\', (FILE));                      \
 746               putc (escape, (FILE));                    \
 747               break;                                    \
 748             }                                           \
 749         }                                               \
 750                                                         \
 751       fprintf ((FILE), "\"\n");                         \
 752     }                                                   \
 753   while (0)
 754
 755 /* The routine used to output sequences of byte values.  We use a special
 756    version of this for most svr4 targets because doing so makes the
 757    generated assembly code more compact (and thus faster to assemble)
 758    as well as more readable.  Note that if we find subparts of the
 759    character sequence which end with NUL (and which are shorter than
 760    STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING.  */
 761
 762 #undef  ASM_OUTPUT_ASCII
 763 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH)                             \
 764   do                                                                    \
 765     {                                                                   \
 766       register const unsigned char *_ascii_bytes =                      \
 767         (const unsigned char *) (STR);                                  \
 768       register const unsigned char *limit = _ascii_bytes + (LENGTH);    \
 769       register unsigned bytes_in_chunk = 0;                             \
 770                                                                         \
 771       for (; _ascii_bytes < limit; _ascii_bytes++)                      \
 772         {                                                               \
 773           register const unsigned char *p;                              \
 774                                                                         \
 775           if (bytes_in_chunk >= 60)                                     \
 776             {                                                           \
 777               fprintf ((FILE), "\"\n");                                 \
 778               bytes_in_chunk = 0;                                       \
 779             }                                                           \
 780                                                                         \
 781           for (p = _ascii_bytes; p < limit && *p != '\0'; p++)          \
 782             continue;                                                   \
 783                                                                         \
 784           if (p < limit && (p - _ascii_bytes) <= (long)STRING_LIMIT)    \
 785             {                                                           \
 786               if (bytes_in_chunk > 0)                                   \
 787                 {                                                       \
 788                   fprintf ((FILE), "\"\n");                             \
 789                   bytes_in_chunk = 0;                                   \
 790                 }                                                       \
 791                                                                         \
 792               ASM_OUTPUT_LIMITED_STRING ((FILE), _ascii_bytes);         \
 793               _ascii_bytes = p;                                         \
 794             }                                                           \
 795           else                                                          \
 796             {                                                           \
 797               register int escape;                                      \
 798               register unsigned ch;                                     \
 799                                                                         \
 800               if (bytes_in_chunk == 0)                                  \
 801                 fprintf ((FILE), "%s\"", ASCII_DATA_ASM_OP);            \
 802                                                                         \
 803               switch (escape = ESCAPES[ch = *_ascii_bytes])             \
 804                 {                                                       \
 805                 case 0:                                                 \
 806                   putc (ch, (FILE));                                    \
 807                   bytes_in_chunk++;                                     \
 808                   break;                                                \
 809                 case 1:                                                 \
 810                   fprintf ((FILE), "\\%03o", ch);                       \
 811                   bytes_in_chunk += 4;                                  \
 812                   break;                                                \
 813                 default:                                                \
 814                   putc ('\\', (FILE));                                  \
 815                   putc (escape, (FILE));                                \
 816                   bytes_in_chunk += 2;                                  \
 817                   break;                                                \
 818                 }                                                       \
 819             }                                                           \
 820         }                                                               \
 821                                                                         \
 822       if (bytes_in_chunk > 0)                                           \
 823         fprintf ((FILE), "\"\n");                                       \
 824     }                                                                   \
 825   while (0)