gcc/config/arm/elf.h

   1 /* Definitions of target machine for GNU compiler.
   2    For ARM with ELF obj format.
   3    Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001
   4    Free Software Foundation, Inc.
   5    Contributed by Philip Blundell <philb@gnu.org> and
   6    Catherine Moore <clm@cygnus.com>
   7
   8 This file is part of GNU CC.
   9
  10 GNU CC is free software; you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation; either version 2, or (at your option)
  13 any later version.
  14
  15 GNU CC is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GNU CC; see the file COPYING.  If not, write to
  22 the Free Software Foundation, 59 Temple Place - Suite 330,
  23 Boston, MA 02111-1307, USA.  */
  24
  25
  26 #define OBJECT_FORMAT_ELF
  27
  28 #ifndef LOCAL_LABEL_PREFIX
  29 #define LOCAL_LABEL_PREFIX "."
  30 #endif
  31
  32 #ifndef USER_LABEL_PREFIX
  33 #define USER_LABEL_PREFIX ""
  34 #endif
  35
  36 #ifndef SUBTARGET_CPP_SPEC
  37 #define SUBTARGET_CPP_SPEC  "-D__ELF__"
  38 #endif
  39
  40 #ifndef SUBTARGET_EXTRA_SPECS
  41 #define SUBTARGET_EXTRA_SPECS \
  42   { "subtarget_extra_asm_spec", SUBTARGET_EXTRA_ASM_SPEC },
  43 #endif
  44
  45 #ifndef SUBTARGET_EXTRA_ASM_SPEC
  46 #define SUBTARGET_EXTRA_ASM_SPEC ""
  47 #endif
  48
  49 #ifndef ASM_SPEC
  50 #define ASM_SPEC "\
  51 %{mbig-endian:-EB} \
  52 %{mcpu=*:-m%*} \
  53 %{march=*:-m%*} \
  54 %{mapcs-*:-mapcs-%*} \
  55 %{mapcs-float:-mfloat} \
  56 %{msoft-float:-mno-fpu} \
  57 %{mthumb-interwork:-mthumb-interwork} \
  58 %(subtarget_extra_asm_spec)"
  59 #endif
  60
  61 /* The following macro defines the format used to output the second
  62    operand of the .type assembler directive.  Different svr4 assemblers
  63    expect various different forms for this operand.  The one given here
  64    is just a default.  You may need to override it in your machine-
  65    specific tm.h file (depending upon the particulars of your assembler).  */
  66 #define TYPE_OPERAND_FMT        "%s"
  67
  68 /* Write the extra assembler code needed to declare a function's result.
  69    Most svr4 assemblers don't require any special declaration of the
  70    result value, but there are exceptions.  */
  71 #ifndef ASM_DECLARE_RESULT
  72 #define ASM_DECLARE_RESULT(FILE, RESULT)
  73 #endif
  74
  75 /* These macros generate the special .type and .size directives which
  76    are used to set the corresponding fields of the linker symbol table
  77    entries in an ELF object file under SVR4.  These macros also output
  78    the starting labels for the relevant functions/objects.  */
  79 #define TYPE_ASM_OP     "\t.type\t"
  80 #define SIZE_ASM_OP     "\t.size\t"
  81
  82 /* Write the extra assembler code needed to declare a function properly.
  83    Some svr4 assemblers need to also have something extra said about the
  84    function's return value.  We allow for that here.  */
  85 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL)     \
  86   do                                                    \
  87     {                                                   \
  88       ARM_DECLARE_FUNCTION_NAME (FILE, NAME, DECL);     \
  89       fprintf (FILE, "%s", TYPE_ASM_OP);                \
  90       assemble_name (FILE, NAME);                       \
  91       putc (',', FILE);                                 \
  92       fprintf (FILE, TYPE_OPERAND_FMT, "function");     \
  93       putc ('\n', FILE);                                \
  94       ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));    \
  95       ASM_OUTPUT_LABEL(FILE, NAME);                     \
  96     }                                                   \
  97   while (0)
  98
  99 /* Write the extra assembler code needed to declare an object properly.  */
 100 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)               \
 101   do                                                            \
 102     {                                                           \
 103       fprintf (FILE, "%s", TYPE_ASM_OP);                        \
 104       assemble_name (FILE, NAME);                               \
 105       putc (',', FILE);                                         \
 106       fprintf (FILE, TYPE_OPERAND_FMT, "object");               \
 107       putc ('\n', FILE);                                        \
 108       size_directive_output = 0;                                \
 109       if (!flag_inhibit_size_directive && DECL_SIZE (DECL))     \
 110         {                                                       \
 111           size_directive_output = 1;                            \
 112           fprintf (FILE, "%s", SIZE_ASM_OP);                    \
 113           assemble_name (FILE, NAME);                           \
 114           putc (',', FILE);                                     \
 115           fprintf (FILE, HOST_WIDE_INT_PRINT_DEC,               \
 116                    int_size_in_bytes (TREE_TYPE (DECL)));       \
 117           fputc ('\n', FILE);                                   \
 118         }                                                       \
 119       ASM_OUTPUT_LABEL(FILE, NAME);                             \
 120     }                                                           \
 121   while (0)
 122
 123 /* Output the size directive for a decl in rest_of_decl_compilation
 124    in the case where we did not do so before the initializer.
 125    Once we find the error_mark_node, we know that the value of
 126    size_directive_output was set
 127    by ASM_DECLARE_OBJECT_NAME when it was run for the same decl.  */
 128 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)        \
 129   do                                                                    \
 130     {                                                                   \
 131       const char * name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);          \
 132       if (!flag_inhibit_size_directive && DECL_SIZE (DECL)              \
 133           && ! AT_END && TOP_LEVEL                                      \
 134           && DECL_INITIAL (DECL) == error_mark_node                     \
 135           && !size_directive_output)                                    \
 136         {                                                               \
 137           size_directive_output = 1;                                    \
 138           fprintf (FILE, "%s", SIZE_ASM_OP);                            \
 139           assemble_name (FILE, name);                                   \
 140           putc (',', FILE);                                             \
 141           fprintf (FILE, HOST_WIDE_INT_PRINT_DEC,                       \
 142                   int_size_in_bytes (TREE_TYPE (DECL)));                \
 143          fputc ('\n', FILE);                                            \
 144         }                                                               \
 145     }                                                                   \
 146   while (0)
 147
 148 /* This is how to declare the size of a function.  */
 149 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)            \
 150   do                                                            \
 151     {                                                           \
 152       ARM_DECLARE_FUNCTION_SIZE (FILE, FNAME, DECL);            \
 153       if (!flag_inhibit_size_directive)                         \
 154         {                                                       \
 155           char label[256];                                      \
 156           static int labelno;                                   \
 157           labelno ++;                                           \
 158           ASM_GENERATE_INTERNAL_LABEL (label, "Lfe", labelno);  \
 159           ASM_OUTPUT_INTERNAL_LABEL (FILE, "Lfe", labelno);     \
 160           fprintf (FILE, "%s", SIZE_ASM_OP);                    \
 161           assemble_name (FILE, (FNAME));                        \
 162           fprintf (FILE, ",");                                  \
 163           assemble_name (FILE, label);                          \
 164           fprintf (FILE, "-");                                  \
 165           assemble_name (FILE, (FNAME));                        \
 166           putc ('\n', FILE);                                    \
 167         }                                                       \
 168     }                                                           \
 169   while (0)
 170
 171 /* Define this macro if jump tables (for `tablejump' insns) should be
 172    output in the text section, along with the assembler instructions.
 173    Otherwise, the readonly data section is used.  */
 174 #define JUMP_TABLES_IN_TEXT_SECTION 1
 175
 176 #ifndef LINK_SPEC
 177 #define LINK_SPEC "%{mbig-endian:-EB} -X"
 178 #endif
 179
 180 /* Run-time Target Specification.  */
 181 #ifndef TARGET_VERSION
 182 #define TARGET_VERSION fputs (" (ARM/elf)", stderr)
 183 #endif
 184
 185 #ifndef TARGET_DEFAULT
 186 #define TARGET_DEFAULT (ARM_FLAG_SOFT_FLOAT | ARM_FLAG_APCS_32 | ARM_FLAG_APCS_FRAME)
 187 #endif
 188
 189 #ifndef MULTILIB_DEFAULTS
 190 #define MULTILIB_DEFAULTS \
 191   { "marm", "mlittle-endian", "msoft-float", "mapcs-32", "mno-thumb-interwork", "fno-leading-underscore" }
 192 #endif
 193 \f
 194
 195 /* This outputs a lot of .req's to define alias for various registers.
 196    Let's try to avoid this.  */
 197 #ifndef ASM_FILE_START
 198 #define ASM_FILE_START(STREAM)                                  \
 199   do                                                            \
 200     {                                                           \
 201       fprintf (STREAM, "%s Generated by gcc %s for ARM/elf\n",  \
 202                ASM_COMMENT_START, version_string);              \
 203       output_file_directive (STREAM, main_input_filename);      \
 204       fprintf (STREAM, ASM_APP_OFF);                            \
 205     }                                                           \
 206   while (0)
 207 #endif
 208
 209 /* Output an internal label definition.  */
 210 #ifndef ASM_OUTPUT_INTERNAL_LABEL
 211 #define ASM_OUTPUT_INTERNAL_LABEL(STREAM, PREFIX, NUM)          \
 212   do                                                            \
 213     {                                                           \
 214       char * s = (char *) alloca (40 + strlen (PREFIX));        \
 215       extern int arm_target_label, arm_ccfsm_state;             \
 216       extern rtx arm_target_insn;                               \
 217                                                                 \
 218       if (arm_ccfsm_state == 3 && arm_target_label == (NUM)     \
 219         && !strcmp (PREFIX, "L"))                               \
 220         {                                                       \
 221           arm_ccfsm_state = 0;                                  \
 222           arm_target_insn = NULL;                               \
 223         }                                                       \
 224         ASM_GENERATE_INTERNAL_LABEL (s, (PREFIX), (NUM));       \
 225         ASM_OUTPUT_LABEL (STREAM, s);                           \
 226     }                                                           \
 227   while (0)
 228 #endif
 229 \f
 230 /* Support the ctors/dtors and other sections.  */
 231
 232 /* Define the pseudo-ops used to switch to the .ctors and .dtors sections.
 233
 234    Note that we want to give these sections the SHF_WRITE attribute
 235    because these sections will actually contain data (i.e. tables of
 236    addresses of functions in the current root executable or shared library
 237    file) and, in the case of a shared library, the relocatable addresses
 238    will have to be properly resolved/relocated (and then written into) by
 239    the dynamic linker when it actually attaches the given shared library
 240    to the executing process.  (Note that on SVR4, you may wish to use the
 241    `-z text' option to the ELF linker, when building a shared library, as
 242    an additional check that you are doing everything right.  But if you do
 243    use the `-z text' option when building a shared library, you will get
 244    errors unless the .ctors and .dtors sections are marked as writable
 245    via the SHF_WRITE attribute.)  */
 246 #ifndef CTORS_SECTION_ASM_OP
 247 #define CTORS_SECTION_ASM_OP    "\t.section\t.ctors,\"aw\""
 248 #endif
 249
 250 #ifndef DTORS_SECTION_ASM_OP
 251 #define DTORS_SECTION_ASM_OP    "\t.section\t.dtors,\"aw\""
 252 #endif
 253
 254 /* A list of other sections which the compiler might be "in" at any
 255    given time.  */
 256 #ifndef SUBTARGET_EXTRA_SECTIONS
 257 #define SUBTARGET_EXTRA_SECTIONS
 258 #endif
 259
 260 #ifndef EXTRA_SECTIONS
 261 #define EXTRA_SECTIONS SUBTARGET_EXTRA_SECTIONS in_ctors, in_dtors
 262 #endif
 263
 264 /* A list of extra section function definitions.  */
 265 #ifndef SUBTARGET_EXTRA_SECTION_FUNCTIONS
 266 #define SUBTARGET_EXTRA_SECTION_FUNCTIONS
 267 #endif
 268
 269 #ifndef EXTRA_SECTION_FUNCTIONS
 270 #define EXTRA_SECTION_FUNCTIONS                 \
 271   SUBTARGET_EXTRA_SECTION_FUNCTIONS             \
 272   CTORS_SECTION_FUNCTION                        \
 273   DTORS_SECTION_FUNCTION
 274 #endif
 275
 276 #ifndef CTORS_SECTION_FUNCTION
 277 #define CTORS_SECTION_FUNCTION                                  \
 278 void                                                            \
 279 ctors_section ()                                                \
 280 {                                                               \
 281   if (in_section != in_ctors)                                   \
 282     {                                                           \
 283       fprintf (asm_out_file, "%s\n", CTORS_SECTION_ASM_OP);     \
 284       in_section = in_ctors;                                    \
 285     }                                                           \
 286 }
 287 #endif
 288
 289 #ifndef DTORS_SECTION_FUNCTION
 290 #define DTORS_SECTION_FUNCTION                                  \
 291 void                                                            \
 292 dtors_section ()                                                \
 293 {                                                               \
 294   if (in_section != in_dtors)                                   \
 295     {                                                           \
 296       fprintf (asm_out_file, "%s\n", DTORS_SECTION_ASM_OP);     \
 297       in_section = in_dtors;                                    \
 298     }                                                           \
 299 }
 300 #endif
 301
 302 /* A C statement to output something to the assembler file to switch to
 303    section NAME for object DECL which is either a FUNCTION_DECL, a VAR_DECL
 304    or NULL_TREE.  */
 305 #undef  ASM_OUTPUT_SECTION_NAME
 306 #define ASM_OUTPUT_SECTION_NAME(STREAM, DECL, NAME, RELOC)              \
 307   do                                                                    \
 308     {                                                                   \
 309       if ((DECL) && TREE_CODE (DECL) == FUNCTION_DECL)                  \
 310         fprintf (STREAM, "\t.section %s,\"ax\",%%progbits\n", NAME);    \
 311       else if ((DECL) && DECL_READONLY_SECTION (DECL, RELOC))           \
 312         fprintf (STREAM, "\t.section %s,\"a\"\n", NAME);                \
 313       else if (! strncmp (NAME, ".bss", 4))                             \
 314         fprintf (STREAM, "\t.section %s,\"aw\",%%nobits\n", NAME);      \
 315       else                                                              \
 316         fprintf (STREAM, "\t.section %s,\"aw\"\n", NAME);               \
 317     }                                                                   \
 318   while (0)
 319 \f
 320 /* Support the ctors/dtors sections for g++.  */
 321 #ifndef INT_ASM_OP
 322 #define INT_ASM_OP      "\t.word\t"
 323 #endif
 324
 325 /* A C statement (sans semicolon) to output an element in the table of
 326    global constructors.  */
 327 #ifndef ASM_OUTPUT_CONSTRUCTOR
 328 #define ASM_OUTPUT_CONSTRUCTOR(STREAM, NAME)    \
 329   do                                            \
 330     {                                           \
 331       ctors_section ();                         \
 332       fprintf (STREAM, "%s", INT_ASM_OP);       \
 333       assemble_name (STREAM, NAME);             \
 334       fprintf (STREAM, "\n");                   \
 335     }                                           \
 336   while (0)
 337 #endif
 338
 339 /* A C statement (sans semicolon) to output an element in the table of
 340    global destructors.  */
 341 #ifndef ASM_OUTPUT_DESTRUCTOR
 342 #define ASM_OUTPUT_DESTRUCTOR(STREAM, NAME)     \
 343   do                                            \
 344     {                                           \
 345       dtors_section ();                         \
 346       fprintf (STREAM, "%s", INT_ASM_OP);       \
 347       assemble_name (STREAM, NAME);             \
 348       fprintf (STREAM, "\n");                   \
 349     }                                           \
 350   while (0)
 351 #endif
 352
 353 /* This is how we tell the assembler that a symbol is weak.  */
 354
 355 #define ASM_WEAKEN_LABEL(FILE, NAME)            \
 356   do                                            \
 357     {                                           \
 358       fputs ("\t.weak\t", FILE);                \
 359       assemble_name (FILE, NAME);               \
 360       fputc ('\n', FILE);                       \
 361     }                                           \
 362   while (0)
 363
 364 #ifndef ASM_OUTPUT_ALIGNED_COMMON
 365 #define ASM_OUTPUT_ALIGNED_COMMON(STREAM, NAME, SIZE, ALIGN)    \
 366   do                                                            \
 367     {                                                           \
 368       fprintf (STREAM, "\t.comm\t");                            \
 369       assemble_name (STREAM, NAME);                             \
 370       fprintf (STREAM, ", %d, %d\n", SIZE, ALIGN);              \
 371     }                                                           \
 372   while (0)
 373 #endif
 374
 375 /* For PIC code we need to explicitly specify (PLT) and (GOT) relocs.  */
 376 #define NEED_PLT_RELOC  flag_pic
 377 #define NEED_GOT_RELOC  flag_pic
 378
 379 /* The ELF assembler handles GOT addressing differently to NetBSD.  */
 380 #define GOT_PCREL       0
 381
 382 /* Biggest alignment supported by the object file format of this
 383    machine.  Use this macro to limit the alignment which can be
 384    specified using the `__attribute__ ((aligned (N)))' construct.  If
 385    not defined, the default value is `BIGGEST_ALIGNMENT'.  */
 386 #define MAX_OFILE_ALIGNMENT (32768 * 8)
 387
 388 /* Align output to a power of two.  Note ".align 0" is redundant,
 389    and also GAS will treat it as ".align 2" which we do not want.  */
 390 #define ASM_OUTPUT_ALIGN(STREAM, POWER)                 \
 391   do                                                    \
 392     {                                                   \
 393       if ((POWER) > 0)                                  \
 394         fprintf (STREAM, "\t.align\t%d\n", POWER);      \
 395     }                                                   \
 396   while (0)
 397
 398 #include "aout.h"