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 Free Software Foundation, Inc.
   4    Contributed by Philip Blundell <philb@gnu.org> and
   5    Catherine Moore <clm@cygnus.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
  25 #define OBJECT_FORMAT_ELF
  26
  27 #ifndef LOCAL_LABEL_PREFIX
  28 #define LOCAL_LABEL_PREFIX "."
  29 #endif
  30
  31 #ifndef USER_LABEL_PREFIX
  32 #define USER_LABEL_PREFIX ""
  33 #endif
  34
  35 #ifndef CPP_PREDEFINES
  36 #define CPP_PREDEFINES "-Darm -Darm_elf -Acpu(arm) -Amachine(arm) -D__ELF__"
  37 #endif
  38
  39 /* The following macro defines the format used to output the second
  40    operand of the .type assembler directive.  Different svr4 assemblers
  41    expect various different forms for this operand.  The one given here
  42    is just a default.  You may need to override it in your machine-
  43    specific tm.h file (depending upon the particulars of your assembler).  */
  44 #define TYPE_OPERAND_FMT        "%s"
  45
  46 /* Write the extra assembler code needed to declare a function's result.
  47    Most svr4 assemblers don't require any special declaration of the
  48    result value, but there are exceptions.  */
  49 #ifndef ASM_DECLARE_RESULT
  50 #define ASM_DECLARE_RESULT(FILE, RESULT)
  51 #endif
  52
  53 /* These macros generate the special .type and .size directives which
  54    are used to set the corresponding fields of the linker symbol table
  55    entries in an ELF object file under SVR4.  These macros also output
  56    the starting labels for the relevant functions/objects.  */
  57 #define TYPE_ASM_OP     ".type"
  58 #define SIZE_ASM_OP     ".size"
  59
  60 /* Write the extra assembler code needed to declare a function properly.
  61    Some svr4 assemblers need to also have something extra said about the
  62    function's return value.  We allow for that here.  */
  63 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL)     \
  64   do                                                    \
  65     {                                                   \
  66       if (TARGET_POKE_FUNCTION_NAME)                    \
  67         arm_poke_function_name (FILE, NAME);            \
  68       fprintf (FILE, "\t%s\t ", TYPE_ASM_OP);           \
  69       assemble_name (FILE, NAME);                       \
  70       putc (',', FILE);                                 \
  71       fprintf (FILE, TYPE_OPERAND_FMT, "function");     \
  72       putc ('\n', FILE);                                \
  73       ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));    \
  74       ASM_OUTPUT_LABEL(FILE, NAME);                     \
  75     }                                                   \
  76   while (0)
  77
  78 /* Write the extra assembler code needed to declare an object properly.  */
  79 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)                       \
  80   do {                                                                  \
  81     fprintf (FILE, "\t%s\t ", TYPE_ASM_OP);                             \
  82     assemble_name (FILE, NAME);                                         \
  83     putc (',', FILE);                                                   \
  84     fprintf (FILE, TYPE_OPERAND_FMT, "object");                         \
  85     putc ('\n', FILE);                                                  \
  86     size_directive_output = 0;                                          \
  87     if (!flag_inhibit_size_directive && DECL_SIZE (DECL))               \
  88       {                                                                 \
  89         size_directive_output = 1;                                      \
  90         fprintf (FILE, "\t%s\t ", SIZE_ASM_OP);                         \
  91         assemble_name (FILE, NAME);                                     \
  92         putc (',', FILE);                                               \
  93         fprintf (FILE, HOST_WIDE_INT_PRINT_DEC,                         \
  94                  int_size_in_bytes (TREE_TYPE (DECL)));                 \
  95         fputc ('\n', FILE);                                             \
  96       }                                                                 \
  97     ASM_OUTPUT_LABEL(FILE, NAME);                                       \
  98   } while (0)
  99
 100 /* Output the size directive for a decl in rest_of_decl_compilation
 101    in the case where we did not do so before the initializer.
 102    Once we find the error_mark_node, we know that the value of
 103    size_directive_output was set
 104    by ASM_DECLARE_OBJECT_NAME when it was run for the same decl.  */
 105 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)         \
 106 do {                                                                     \
 107      char * name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);                  \
 108      if (!flag_inhibit_size_directive && DECL_SIZE (DECL)                \
 109          && ! AT_END && TOP_LEVEL                                        \
 110          && DECL_INITIAL (DECL) == error_mark_node                       \
 111          && !size_directive_output)                                      \
 112        {                                                                 \
 113          size_directive_output = 1;                                      \
 114          fprintf (FILE, "\t%s\t ", SIZE_ASM_OP);                         \
 115          assemble_name (FILE, name);                                     \
 116          putc (',', FILE);                                               \
 117          fprintf (FILE, HOST_WIDE_INT_PRINT_DEC,                         \
 118                   int_size_in_bytes (TREE_TYPE (DECL)));                 \
 119         fputc ('\n', FILE);                                              \
 120        }                                                                 \
 121    } while (0)
 122
 123 /* This is how to declare the size of a function.  */
 124 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)                    \
 125   do {                                                                  \
 126     if (!flag_inhibit_size_directive)                                   \
 127       {                                                                 \
 128         char label[256];                                                \
 129         static int labelno;                                             \
 130         labelno ++;                                                     \
 131         ASM_GENERATE_INTERNAL_LABEL (label, "Lfe", labelno);            \
 132         ASM_OUTPUT_INTERNAL_LABEL (FILE, "Lfe", labelno);               \
 133         fprintf (FILE, "\t%s\t ", SIZE_ASM_OP);                         \
 134         assemble_name (FILE, (FNAME));                                  \
 135         fprintf (FILE, ",");                                            \
 136         assemble_name (FILE, label);                                    \
 137         fprintf (FILE, "-");                                            \
 138         assemble_name (FILE, (FNAME));                                  \
 139         putc ('\n', FILE);                                              \
 140       }                                                                 \
 141   } while (0)
 142
 143 /* Define this macro if jump tables (for `tablejump' insns) should be
 144    output in the text section, along with the assembler instructions.
 145    Otherwise, the readonly data section is used.  */
 146 #define JUMP_TABLES_IN_TEXT_SECTION 1
 147
 148 #ifndef ASM_SPEC
 149 #define ASM_SPEC "%{mbig-endian:-EB} %{mcpu=*:-m%*} %{march=*:-m%*} \
 150  %{mapcs-*:-mapcs-%*} %{mthumb-interwork:-mthumb-interwork} %{mapcs-float:mfloat}"
 151 #endif
 152
 153 #ifndef LINK_SPEC
 154 #define LINK_SPEC "%{mbig-endian:-EB} -X"
 155 #endif
 156
 157 /* Run-time Target Specification.  */
 158 #ifndef TARGET_VERSION
 159 #define TARGET_VERSION fputs (" (ARM/elf)", stderr)
 160 #endif
 161
 162 #ifndef TARGET_DEFAULT
 163 #define TARGET_DEFAULT (ARM_FLAG_SOFT_FLOAT | ARM_FLAG_APCS_32)
 164 #endif
 165
 166 #ifndef MULTILIB_DEFAULTS
 167 #define MULTILIB_DEFAULTS { "mlittle-endian", "msoft-float", "mapcs-32", "mno-thumb-interwork" }
 168 #endif
 169
 170 /* Setting this to 32 produces more efficient code, but the value set in previous
 171    versions of this toolchain was 8, which produces more compact structures. The
 172    command line option -mstructure_size_boundary=<n> can be used to change this
 173    value.  */
 174 #undef  STRUCTURE_SIZE_BOUNDARY
 175 #define STRUCTURE_SIZE_BOUNDARY arm_structure_size_boundary
 176
 177 extern int arm_structure_size_boundary;
 178
 179 /* A C expression whose value is nonzero if IDENTIFIER with arguments ARGS
 180    is a valid machine specific attribute for DECL.
 181    The attributes in ATTRIBUTES have previously been assigned to DECL.  */
 182 #define VALID_MACHINE_DECL_ATTRIBUTE(DECL, ATTRIBUTES, IDENTIFIER, ARGS) \
 183 arm_valid_machine_decl_attribute (DECL, IDENTIFIER, ARGS)
 184 \f
 185
 186 /* A C statement to output assembler commands which will identify the
 187    object file as having been compiled with GNU CC (or another GNU
 188    compiler).  */
 189 /* Define this to NULL so we don't get anything.
 190    We have ASM_IDENTIFY_LANGUAGE.
 191    Also, when using stabs, gcc2_compiled must be a stabs entry, not an
 192    ordinary symbol, or gdb won't see it.  The stabs entry must be
 193    before the N_SO in order for gdb to find it.  */
 194 #ifndef ASM_IDENTIFY_GCC
 195 #define ASM_IDENTIFY_GCC(STREAM)                                \
 196      fprintf (STREAM, "%sgcc2_compiled.:\n", LOCAL_LABEL_PREFIX )
 197 #endif
 198
 199 /* This outputs a lot of .req's to define alias for various registers.
 200    Let's try to avoid this.  */
 201 #ifndef ASM_FILE_START
 202 #define ASM_FILE_START(STREAM) \
 203 do {                                                            \
 204   extern char * version_string;                                 \
 205   fprintf (STREAM, "%s Generated by gcc %s for ARM/elf\n",      \
 206            ASM_COMMENT_START, version_string);                  \
 207   output_file_directive ((STREAM), main_input_filename);        \
 208 } while (0)
 209 #endif
 210
 211 /* Output an internal label definition.  */
 212 #ifndef ASM_OUTPUT_INTERNAL_LABEL
 213 #define ASM_OUTPUT_INTERNAL_LABEL(STREAM, PREFIX, NUM)          \
 214   do                                                            \
 215     {                                                           \
 216       char * s = (char *) alloca (40 + strlen (PREFIX));        \
 217       extern int arm_target_label, arm_ccfsm_state;             \
 218       extern rtx arm_target_insn;                               \
 219                                                                 \
 220       if (arm_ccfsm_state == 3 && arm_target_label == (NUM)     \
 221         && !strcmp (PREFIX, "L"))                               \
 222         {                                                       \
 223           arm_ccfsm_state = 0;                                  \
 224           arm_target_insn = NULL;                               \
 225         }                                                       \
 226         ASM_GENERATE_INTERNAL_LABEL (s, (PREFIX), (NUM));       \
 227         ASM_OUTPUT_LABEL (STREAM, s);                           \
 228     } while (0)
 229 #endif
 230 \f
 231 /* Support the ctors/dtors and other sections.  */
 232
 233 /* Define the pseudo-ops used to switch to the .ctors and .dtors sections.
 234
 235    Note that we want to give these sections the SHF_WRITE attribute
 236    because these sections will actually contain data (i.e. tables of
 237    addresses of functions in the current root executable or shared library
 238    file) and, in the case of a shared library, the relocatable addresses
 239    will have to be properly resolved/relocated (and then written into) by
 240    the dynamic linker when it actually attaches the given shared library
 241    to the executing process.  (Note that on SVR4, you may wish to use the
 242    `-z text' option to the ELF linker, when building a shared library, as
 243    an additional check that you are doing everything right.  But if you do
 244    use the `-z text' option when building a shared library, you will get
 245    errors unless the .ctors and .dtors sections are marked as writable
 246    via the SHF_WRITE attribute.)  */
 247 #ifndef CTORS_SECTION_ASM_OP
 248 #define CTORS_SECTION_ASM_OP    "\t.section\t.ctors,\"aw\""
 249 #endif
 250
 251 #ifndef DTORS_SECTION_ASM_OP
 252 #define DTORS_SECTION_ASM_OP    "\t.section\t.dtors,\"aw\""
 253 #endif
 254
 255 /* A list of other sections which the compiler might be "in" at any
 256    given time.  */
 257 #ifndef SUBTARGET_EXTRA_SECTIONS
 258 #define SUBTARGET_EXTRA_SECTIONS
 259 #endif
 260
 261 #ifndef EXTRA_SECTIONS
 262 #define EXTRA_SECTIONS SUBTARGET_EXTRA_SECTIONS in_ctors, in_dtors
 263 #endif
 264
 265 /* A list of extra section function definitions.  */
 266 #ifndef SUBTARGET_EXTRA_SECTION_FUNCTIONS
 267 #define SUBTARGET_EXTRA_SECTION_FUNCTIONS
 268 #endif
 269
 270 #ifndef EXTRA_SECTION_FUNCTIONS
 271 #define EXTRA_SECTION_FUNCTIONS                 \
 272   SUBTARGET_EXTRA_SECTION_FUNCTIONS             \
 273   CTORS_SECTION_FUNCTION                        \
 274   DTORS_SECTION_FUNCTION
 275 #endif
 276
 277 #ifndef CTORS_SECTION_FUNCTION
 278 #define CTORS_SECTION_FUNCTION                                          \
 279 void                                                                    \
 280 ctors_section ()                                                        \
 281 {                                                                       \
 282   if (in_section != in_ctors)                                           \
 283     {                                                                   \
 284       fprintf (asm_out_file, "%s\n", CTORS_SECTION_ASM_OP);             \
 285       in_section = in_ctors;                                            \
 286     }                                                                   \
 287 }
 288 #endif
 289
 290 #ifndef DTORS_SECTION_FUNCTION
 291 #define DTORS_SECTION_FUNCTION                                          \
 292 void                                                                    \
 293 dtors_section ()                                                        \
 294 {                                                                       \
 295   if (in_section != in_dtors)                                           \
 296     {                                                                   \
 297       fprintf (asm_out_file, "%s\n", DTORS_SECTION_ASM_OP);             \
 298       in_section = in_dtors;                                            \
 299     }                                                                   \
 300 }
 301 #endif
 302 \f
 303 /* Support the ctors/dtors sections for g++.  */
 304 #ifndef INT_ASM_OP
 305 #define INT_ASM_OP      ".word"
 306 #endif
 307
 308 /* A C statement (sans semicolon) to output an element in the table of
 309    global constructors.  */
 310 #ifndef ASM_OUTPUT_CONSTRUCTOR
 311 #define ASM_OUTPUT_CONSTRUCTOR(STREAM,NAME) \
 312 do {                                            \
 313   ctors_section ();                             \
 314   fprintf (STREAM, "\t%s\t ", INT_ASM_OP);      \
 315   assemble_name (STREAM, NAME);                 \
 316   fprintf (STREAM, "\n");                       \
 317 } while (0)
 318 #endif
 319
 320 /* A C statement (sans semicolon) to output an element in the table of
 321    global destructors.  */
 322 #ifndef ASM_OUTPUT_DESTRUCTOR
 323 #define ASM_OUTPUT_DESTRUCTOR(STREAM,NAME) \
 324 do {                                            \
 325   dtors_section ();                             \
 326   fprintf (STREAM, "\t%s\t ", INT_ASM_OP);      \
 327   assemble_name (STREAM, NAME);                 \
 328   fprintf (STREAM, "\n");                       \
 329 } while (0)
 330 #endif
 331
 332 /* This is how we tell the assembler that a symbol is weak.  */
 333
 334 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 335   do { fputs ("\t.weak\t", FILE); assemble_name (FILE, NAME); \
 336        fputc ('\n', FILE); } while (0)
 337
 338 /* For PIC code we need to explicitly specify (PLT) and (GOT) relocs.  */
 339 #define NEED_PLT_GOT    flag_pic
 340
 341 /* The ELF assembler handles GOT addressing differently to NetBSD.  */
 342 #define GOT_PCREL       0
 343
 344 /* Biggest alignment supported by the object file format of this
 345    machine.  Use this macro to limit the alignment which can be
 346    specified using the `__attribute__ ((aligned (N)))' construct.  If
 347    not defined, the default value is `BIGGEST_ALIGNMENT'.  */
 348 #define MAX_OFILE_ALIGNMENT (32768*8)
 349
 350 /* Align output to a power of two.  */
 351 #define ASM_OUTPUT_ALIGN(STREAM, POWER)  \
 352    fprintf (STREAM, "\t.align\t%d\n", POWER)
 353
 354 #include "arm/aout.h"