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     fprintf (FILE, "\t%s\t ", TYPE_ASM_OP);                             \
  66     assemble_name (FILE, NAME);                                         \
  67     putc (',', FILE);                                                   \
  68     fprintf (FILE, TYPE_OPERAND_FMT, "function");                       \
  69     putc ('\n', FILE);                                                  \
  70     ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));                      \
  71     ASM_OUTPUT_LABEL(FILE, NAME);                                       \
  72   } while (0)
  73
  74 /* Write the extra assembler code needed to declare an object properly.  */
  75 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)                       \
  76   do {                                                                  \
  77     fprintf (FILE, "\t%s\t ", TYPE_ASM_OP);                             \
  78     assemble_name (FILE, NAME);                                         \
  79     putc (',', FILE);                                                   \
  80     fprintf (FILE, TYPE_OPERAND_FMT, "object");                         \
  81     putc ('\n', FILE);                                                  \
  82     size_directive_output = 0;                                          \
  83     if (!flag_inhibit_size_directive && DECL_SIZE (DECL))               \
  84       {                                                                 \
  85         size_directive_output = 1;                                      \
  86         fprintf (FILE, "\t%s\t ", SIZE_ASM_OP);                         \
  87         assemble_name (FILE, NAME);                                     \
  88         putc (',', FILE);                                               \
  89         fprintf (FILE, HOST_WIDE_INT_PRINT_DEC,                         \
  90                  int_size_in_bytes (TREE_TYPE (DECL)));                 \
  91         fputc ('\n', FILE);                                             \
  92       }                                                                 \
  93     ASM_OUTPUT_LABEL(FILE, NAME);                                       \
  94   } while (0)
  95
  96 /* Output the size directive for a decl in rest_of_decl_compilation
  97    in the case where we did not do so before the initializer.
  98    Once we find the error_mark_node, we know that the value of
  99    size_directive_output was set
 100    by ASM_DECLARE_OBJECT_NAME when it was run for the same decl.  */
 101 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)         \
 102 do {                                                                     \
 103      char * name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);                  \
 104      if (!flag_inhibit_size_directive && DECL_SIZE (DECL)                \
 105          && ! AT_END && TOP_LEVEL                                        \
 106          && DECL_INITIAL (DECL) == error_mark_node                       \
 107          && !size_directive_output)                                      \
 108        {                                                                 \
 109          size_directive_output = 1;                                      \
 110          fprintf (FILE, "\t%s\t ", SIZE_ASM_OP);                         \
 111          assemble_name (FILE, name);                                     \
 112          putc (',', FILE);                                               \
 113          fprintf (FILE, HOST_WIDE_INT_PRINT_DEC,                         \
 114                   int_size_in_bytes (TREE_TYPE (DECL)));                 \
 115         fputc ('\n', FILE);                                              \
 116        }                                                                 \
 117    } while (0)
 118
 119 /* This is how to declare the size of a function.  */
 120 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)                    \
 121   do {                                                                  \
 122     if (!flag_inhibit_size_directive)                                   \
 123       {                                                                 \
 124         char label[256];                                                \
 125         static int labelno;                                             \
 126         labelno ++;                                                     \
 127         ASM_GENERATE_INTERNAL_LABEL (label, "Lfe", labelno);            \
 128         ASM_OUTPUT_INTERNAL_LABEL (FILE, "Lfe", labelno);               \
 129         fprintf (FILE, "\t%s\t ", SIZE_ASM_OP);                         \
 130         assemble_name (FILE, (FNAME));                                  \
 131         fprintf (FILE, ",");                                            \
 132         assemble_name (FILE, label);                                    \
 133         fprintf (FILE, "-");                                            \
 134         assemble_name (FILE, (FNAME));                                  \
 135         putc ('\n', FILE);                                              \
 136       }                                                                 \
 137   } while (0)
 138
 139 /* Define this macro if jump tables (for `tablejump' insns) should be
 140    output in the text section, along with the assembler instructions.
 141    Otherwise, the readonly data section is used.  */
 142 #define JUMP_TABLES_IN_TEXT_SECTION 1
 143
 144 #ifndef ASM_SPEC
 145 #define ASM_SPEC "%{mbig-endian:-EB} %{mcpu=*:-m%*} %{march=*:-m%*} \
 146  %{mapcs-*:-mapcs-%*} %{mthumb-interwork:-mthumb-interwork} %{mapcs-float:mfloat}"
 147 #endif
 148
 149 #ifndef LINK_SPEC
 150 #define LINK_SPEC "%{mbig-endian:-EB} -X"
 151 #endif
 152
 153 /* Run-time Target Specification.  */
 154 #ifndef TARGET_VERSION
 155 #define TARGET_VERSION fputs (" (ARM/elf)", stderr)
 156 #endif
 157
 158 #ifndef TARGET_DEFAULT
 159 #define TARGET_DEFAULT (ARM_FLAG_SOFT_FLOAT | ARM_FLAG_APCS_32)
 160 #endif
 161
 162 #ifndef MULTILIB_DEFAULTS
 163 #define MULTILIB_DEFAULTS { "mlittle-endian", "msoft-float", "mapcs-32", "mno-thumb-interwork" }
 164 #endif
 165
 166 /* Setting this to 32 produces more efficient code, but the value set in previous
 167    versions of this toolchain was 8, which produces more compact structures. The
 168    command line option -mstructure_size_boundary=<n> can be used to change this
 169    value.  */
 170 #undef  STRUCTURE_SIZE_BOUNDARY
 171 #define STRUCTURE_SIZE_BOUNDARY arm_structure_size_boundary
 172
 173 extern int arm_structure_size_boundary;
 174
 175 /* A C expression whose value is nonzero if IDENTIFIER with arguments ARGS
 176    is a valid machine specific attribute for DECL.
 177    The attributes in ATTRIBUTES have previously been assigned to DECL.  */
 178 extern int arm_valid_machine_decl_attribute ();
 179 #define VALID_MACHINE_DECL_ATTRIBUTE(DECL, ATTRIBUTES, IDENTIFIER, ARGS) \
 180 arm_valid_machine_decl_attribute (DECL, ATTRIBUTES, IDENTIFIER, ARGS)
 181 \f
 182
 183 /* A C statement to output assembler commands which will identify the
 184    object file as having been compiled with GNU CC (or another GNU
 185    compiler).  */
 186 /* Define this to NULL so we don't get anything.
 187    We have ASM_IDENTIFY_LANGUAGE.
 188    Also, when using stabs, gcc2_compiled must be a stabs entry, not an
 189    ordinary symbol, or gdb won't see it.  The stabs entry must be
 190    before the N_SO in order for gdb to find it.  */
 191 #ifndef ASM_IDENTIFY_GCC
 192 #define ASM_IDENTIFY_GCC(STREAM)                                \
 193      fprintf (STREAM, "%sgcc2_compiled.:\n", LOCAL_LABEL_PREFIX )
 194 #endif
 195
 196 /* This outputs a lot of .req's to define alias for various registers.
 197    Let's try to avoid this.  */
 198 #ifndef ASM_FILE_START
 199 #define ASM_FILE_START(STREAM) \
 200 do {                                                            \
 201   extern char * version_string;                                 \
 202   fprintf (STREAM, "%s Generated by gcc %s for ARM/elf\n",      \
 203            ASM_COMMENT_START, version_string);                  \
 204   output_file_directive ((STREAM), main_input_filename);        \
 205 } while (0)
 206 #endif
 207
 208 /* Output an internal label definition.  */
 209 #ifndef ASM_OUTPUT_INTERNAL_LABEL
 210 #define ASM_OUTPUT_INTERNAL_LABEL(STREAM, PREFIX, NUM)          \
 211   do                                                            \
 212     {                                                           \
 213       char * s = (char *) alloca (40 + strlen (PREFIX));        \
 214       extern int arm_target_label, arm_ccfsm_state;             \
 215       extern rtx arm_target_insn;                               \
 216                                                                 \
 217       if (arm_ccfsm_state == 3 && arm_target_label == (NUM)     \
 218         && !strcmp (PREFIX, "L"))                               \
 219         {                                                       \
 220           arm_ccfsm_state = 0;                                  \
 221           arm_target_insn = NULL;                               \
 222         }                                                       \
 223         ASM_GENERATE_INTERNAL_LABEL (s, (PREFIX), (NUM));       \
 224         ASM_OUTPUT_LABEL (STREAM, s);                           \
 225     } while (0)
 226 #endif
 227 \f
 228 /* Support the ctors/dtors and other sections.  */
 229
 230 /* Define the pseudo-ops used to switch to the .ctors and .dtors sections.
 231
 232    Note that we want to give these sections the SHF_WRITE attribute
 233    because these sections will actually contain data (i.e. tables of
 234    addresses of functions in the current root executable or shared library
 235    file) and, in the case of a shared library, the relocatable addresses
 236    will have to be properly resolved/relocated (and then written into) by
 237    the dynamic linker when it actually attaches the given shared library
 238    to the executing process.  (Note that on SVR4, you may wish to use the
 239    `-z text' option to the ELF linker, when building a shared library, as
 240    an additional check that you are doing everything right.  But if you do
 241    use the `-z text' option when building a shared library, you will get
 242    errors unless the .ctors and .dtors sections are marked as writable
 243    via the SHF_WRITE attribute.)  */
 244 #ifndef CTORS_SECTION_ASM_OP
 245 #define CTORS_SECTION_ASM_OP    "\t.section\t.ctors,\"aw\""
 246 #endif
 247
 248 #ifndef DTORS_SECTION_ASM_OP
 249 #define DTORS_SECTION_ASM_OP    "\t.section\t.dtors,\"aw\""
 250 #endif
 251
 252 /* A list of other sections which the compiler might be "in" at any
 253    given time.  */
 254 #ifndef SUBTARGET_EXTRA_SECTIONS
 255 #define SUBTARGET_EXTRA_SECTIONS
 256 #endif
 257
 258 #ifndef EXTRA_SECTIONS
 259 #define EXTRA_SECTIONS SUBTARGET_EXTRA_SECTIONS in_ctors, in_dtors
 260 #endif
 261
 262 /* A list of extra section function definitions.  */
 263 #ifndef SUBTARGET_EXTRA_SECTION_FUNCTIONS
 264 #define SUBTARGET_EXTRA_SECTION_FUNCTIONS
 265 #endif
 266
 267 #ifndef EXTRA_SECTION_FUNCTIONS
 268 #define EXTRA_SECTION_FUNCTIONS                 \
 269   SUBTARGET_EXTRA_SECTION_FUNCTIONS             \
 270   CTORS_SECTION_FUNCTION                        \
 271   DTORS_SECTION_FUNCTION
 272 #endif
 273
 274 #ifndef CTORS_SECTION_FUNCTION
 275 #define CTORS_SECTION_FUNCTION                                          \
 276 void                                                                    \
 277 ctors_section ()                                                        \
 278 {                                                                       \
 279   if (in_section != in_ctors)                                           \
 280     {                                                                   \
 281       fprintf (asm_out_file, "%s\n", CTORS_SECTION_ASM_OP);             \
 282       in_section = in_ctors;                                            \
 283     }                                                                   \
 284 }
 285 #endif
 286
 287 #ifndef DTORS_SECTION_FUNCTION
 288 #define DTORS_SECTION_FUNCTION                                          \
 289 void                                                                    \
 290 dtors_section ()                                                        \
 291 {                                                                       \
 292   if (in_section != in_dtors)                                           \
 293     {                                                                   \
 294       fprintf (asm_out_file, "%s\n", DTORS_SECTION_ASM_OP);             \
 295       in_section = in_dtors;                                            \
 296     }                                                                   \
 297 }
 298 #endif
 299 \f
 300 /* Support the ctors/dtors sections for g++.  */
 301 #ifndef INT_ASM_OP
 302 #define INT_ASM_OP      ".word"
 303 #endif
 304
 305 /* A C statement (sans semicolon) to output an element in the table of
 306    global constructors.  */
 307 #ifndef ASM_OUTPUT_CONSTRUCTOR
 308 #define ASM_OUTPUT_CONSTRUCTOR(STREAM,NAME) \
 309 do {                                            \
 310   ctors_section ();                             \
 311   fprintf (STREAM, "\t%s\t ", INT_ASM_OP);      \
 312   assemble_name (STREAM, NAME);                 \
 313   fprintf (STREAM, "\n");                       \
 314 } while (0)
 315 #endif
 316
 317 /* A C statement (sans semicolon) to output an element in the table of
 318    global destructors.  */
 319 #ifndef ASM_OUTPUT_DESTRUCTOR
 320 #define ASM_OUTPUT_DESTRUCTOR(STREAM,NAME) \
 321 do {                                            \
 322   dtors_section ();                             \
 323   fprintf (STREAM, "\t%s\t ", INT_ASM_OP);      \
 324   assemble_name (STREAM, NAME);                 \
 325   fprintf (STREAM, "\n");                       \
 326 } while (0)
 327 #endif
 328
 329 /* This is how we tell the assembler that a symbol is weak.  */
 330
 331 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 332   do { fputs ("\t.weak\t", FILE); assemble_name (FILE, NAME); \
 333        fputc ('\n', FILE); } while (0)
 334
 335 #include "arm/aout.h"