gas/config/tc-arm.h

   1 /* This file is tc-arm.h
   2    Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
   3    2004, 2005, 2006, 2007, 2008, 2009  Free Software Foundation, Inc.
   4    Contributed by Richard Earnshaw (rwe@pegasus.esprit.ec.org)
   5         Modified by David Taylor (dtaylor@armltd.co.uk)
   6
   7    This file is part of GAS, the GNU Assembler.
   8
   9    GAS 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 3, or (at your option)
  12    any later version.
  13
  14    GAS 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 GAS; see the file COPYING.  If not, write to the Free
  21    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  22    02110-1301, USA.  */
  23
  24 #define TC_ARM 1
  25
  26 #ifndef TARGET_BYTES_BIG_ENDIAN
  27 #define TARGET_BYTES_BIG_ENDIAN 0
  28 #endif
  29
  30 #define WORKING_DOT_WORD
  31
  32 #define COFF_MAGIC      ARMMAGIC
  33 #define TARGET_ARCH     bfd_arch_arm
  34
  35 #define DIFF_EXPR_OK
  36
  37 #ifdef  LITTLE_ENDIAN
  38 #undef  LITTLE_ENDIAN
  39 #endif
  40
  41 #ifdef  BIG_ENDIAN
  42 #undef  BIG_ENDIAN
  43 #endif
  44
  45 #define LITTLE_ENDIAN   1234
  46 #define BIG_ENDIAN      4321
  47
  48 struct fix;
  49
  50 #if defined OBJ_AOUT
  51 # if defined TE_RISCIX
  52 #  define TARGET_FORMAT "a.out-riscix"
  53 # elif defined TE_LINUX
  54 #  define ARM_BI_ENDIAN
  55 #  define TARGET_FORMAT "a.out-arm-linux"
  56 # elif defined TE_NetBSD
  57 #  define TARGET_FORMAT "a.out-arm-netbsd"
  58 # else
  59 #  define ARM_BI_ENDIAN
  60 #  define TARGET_FORMAT (target_big_endian ? "a.out-arm-big" : "a.out-arm-little")
  61 # endif
  62 #elif defined OBJ_AIF
  63 # define TARGET_FORMAT "aif"
  64 #elif defined OBJ_COFF
  65 # define ARM_BI_ENDIAN
  66 # if defined TE_PE
  67 #  if defined TE_EPOC
  68 #   define TARGET_FORMAT (target_big_endian ? "epoc-pe-arm-big" : "epoc-pe-arm-little")
  69 #  elif defined TE_WINCE
  70 #   define TARGET_FORMAT (target_big_endian ? "pe-arm-wince-big" : "pe-arm-wince-little")
  71 #  else
  72 #   define TARGET_FORMAT (target_big_endian ? "pe-arm-big" : "pe-arm-little")
  73 #  endif
  74 # else
  75 #  define TARGET_FORMAT (target_big_endian ? "coff-arm-big" : "coff-arm-little")
  76 # endif
  77 #elif defined OBJ_ELF
  78 # define ARM_BI_ENDIAN
  79 # define TARGET_FORMAT  elf32_arm_target_format ()
  80 #endif
  81
  82 #define TC_FORCE_RELOCATION(FIX) arm_force_relocation (FIX)
  83
  84 #define md_relax_frag(segment, fragp, stretch) \
  85   arm_relax_frag (segment, fragp, stretch)
  86 extern int arm_relax_frag (asection *, struct frag *, long);
  87
  88 #define md_optimize_expr(l,o,r)         arm_optimize_expr (l, o, r)
  89 extern int arm_optimize_expr (expressionS *, operatorT, expressionS *);
  90
  91 #define md_cleanup() arm_cleanup ()
  92
  93 #define md_start_line_hook() arm_start_line_hook ()
  94
  95 #define tc_frob_label(S) arm_frob_label (S)
  96
  97 /* We also need to mark assembler created symbols:  */
  98 #define tc_frob_fake_label(S) arm_frob_label (S)
  99
 100 #ifdef OBJ_ELF
 101 #define md_end arm_md_end
 102 extern void arm_md_end (void);
 103 bfd_boolean arm_is_eabi (void);
 104 #endif
 105
 106 /* NOTE: The fake label creation in stabs.c:s_stab_generic() has
 107    deliberately not been updated to mark assembler created stabs
 108    symbols as Thumb.  */
 109
 110 #define TC_FIX_TYPE int
 111 #define TC_INIT_FIX_DATA(FIX) ((FIX)->tc_fix_data = 0)
 112
 113 /* We need to keep some local information on symbols.  */
 114
 115 #define TC_SYMFIELD_TYPE        unsigned int
 116 #define ARM_GET_FLAG(s)         (*symbol_get_tc (s))
 117 #define ARM_SET_FLAG(s,v)       (*symbol_get_tc (s) |= (v))
 118 #define ARM_RESET_FLAG(s,v)     (*symbol_get_tc (s) &= ~(v))
 119
 120 #define ARM_FLAG_THUMB          (1 << 0)        /* The symbol is a Thumb symbol rather than an Arm symbol.  */
 121 #define ARM_FLAG_INTERWORK      (1 << 1)        /* The symbol is attached to code that supports interworking.  */
 122 #define THUMB_FLAG_FUNC         (1 << 2)        /* The symbol is attached to the start of a Thumb function.  */
 123
 124 #define ARM_IS_THUMB(s)         (ARM_GET_FLAG (s) & ARM_FLAG_THUMB)
 125 #define ARM_IS_INTERWORK(s)     (ARM_GET_FLAG (s) & ARM_FLAG_INTERWORK)
 126
 127 #ifdef OBJ_ELF
 128
 129 /* For ELF objects THUMB_IS_FUNC is inferred from
 130    ARM_IS_THUMB and the function type.  */
 131 #define THUMB_IS_FUNC(s)                                        \
 132   ((s) != NULL                                                  \
 133    && ((arm_is_eabi ()                                          \
 134         && (ARM_IS_THUMB (s))                                   \
 135         && (symbol_get_bfdsym (s)->flags & BSF_FUNCTION))       \
 136        || (ARM_GET_FLAG (s) & THUMB_FLAG_FUNC)))
 137
 138 #define ARM_IS_FUNC(s)                                  \
 139   (((s) != NULL                                         \
 140     && arm_is_eabi ()                                   \
 141     && !(ARM_IS_THUMB (s))                              \
 142     /* && !(THUMB_FLAG_FUNC & ARM_GET_FLAG (s)) \ */    \
 143     && (symbol_get_bfdsym (s)->flags & BSF_FUNCTION)))
 144
 145
 146 #else
 147
 148 #define THUMB_IS_FUNC(s)        ((s) && ARM_GET_FLAG (s) & THUMB_FLAG_FUNC)
 149 #define ARM_IS_FUNC(s)          (!THUMB_IS_FUNC (s) \
 150                                  && (s) && (symbol_get_bfdsym (s)->flags & BSF_FUNCTION))
 151 #endif
 152
 153 #define ARM_SET_THUMB(s,t)      ((t) ? ARM_SET_FLAG (s, ARM_FLAG_THUMB)     : ARM_RESET_FLAG (s, ARM_FLAG_THUMB))
 154 #define ARM_SET_INTERWORK(s,t)  ((t) ? ARM_SET_FLAG (s, ARM_FLAG_INTERWORK) : ARM_RESET_FLAG (s, ARM_FLAG_INTERWORK))
 155 #define THUMB_SET_FUNC(s,t)     ((t) ? ARM_SET_FLAG (s, THUMB_FLAG_FUNC)    : ARM_RESET_FLAG (s, THUMB_FLAG_FUNC))
 156
 157 void arm_copy_symbol_attributes (symbolS *, symbolS *);
 158
 159 #ifndef TC_COPY_SYMBOL_ATTRIBUTES
 160 #define TC_COPY_SYMBOL_ATTRIBUTES(DEST, SRC) \
 161   (arm_copy_symbol_attributes (DEST, SRC))
 162 #endif
 163
 164 #define TC_START_LABEL(C,STR)            (c == ':' || (c == '/' && arm_data_in_code ()))
 165 #define tc_canonicalize_symbol_name(str) arm_canonicalize_symbol_name (str);
 166 #define obj_adjust_symtab()              arm_adjust_symtab ()
 167
 168 #define LISTING_HEADER "ARM GAS "
 169
 170 #define OPTIONAL_REGISTER_PREFIX '%'
 171
 172 #define LOCAL_LABEL(name)  (name[0] == '.' && name[1] == 'L')
 173 #define LOCAL_LABELS_FB    1
 174
 175 /* This expression evaluates to true if the relocation is for a local
 176    object for which we still want to do the relocation at runtime.
 177    False if we are willing to perform this relocation while building
 178    the .o file.  GOTOFF does not need to be checked here because it is
 179    not pcrel.  I am not sure if some of the others are ever used with
 180    pcrel, but it is easier to be safe than sorry.  */
 181
 182 #define TC_FORCE_RELOCATION_LOCAL(FIX)                  \
 183   (!(FIX)->fx_pcrel                                     \
 184    || (FIX)->fx_r_type == BFD_RELOC_ARM_GOT32           \
 185    || (FIX)->fx_r_type == BFD_RELOC_32                  \
 186    || TC_FORCE_RELOCATION (FIX))
 187
 188 /* Force output of R_ARM_REL32 relocations against thumb function symbols.
 189    This is needed to ensure the low bit is handled correctly.  */
 190 #define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG)  \
 191   (THUMB_IS_FUNC ((FIX)->fx_addsy)              \
 192    || !SEG_NORMAL (SEG))
 193
 194 #define TC_CONS_FIX_NEW cons_fix_new_arm
 195
 196 #define MAX_MEM_ALIGNMENT_BYTES    6
 197 #define MAX_MEM_FOR_RS_ALIGN_CODE ((1 << MAX_MEM_ALIGNMENT_BYTES) - 1)
 198
 199 /* For frags in code sections we need to record whether they contain
 200    ARM code or THUMB code.  This is that if they have to be aligned,
 201    they can contain the correct type of no-op instruction.  */
 202 struct arm_frag_type
 203 {
 204   int thumb_mode;
 205 #ifdef OBJ_ELF
 206   /* If there is a mapping symbol at offset 0 in this frag,
 207      it will be saved in FIRST_MAP.  If there are any mapping
 208      symbols in this frag, the last one will be saved in
 209      LAST_MAP.  */
 210   symbolS *first_map, *last_map;
 211 #endif
 212 };
 213
 214 #define TC_FRAG_TYPE            struct arm_frag_type
 215 /* NOTE: max_chars is a local variable from frag_var / frag_variant.  */
 216 #define TC_FRAG_INIT(fragp)     arm_init_frag (fragp, max_chars)
 217 #define HANDLE_ALIGN(fragp)     arm_handle_align (fragp)
 218
 219 #define md_do_align(N, FILL, LEN, MAX, LABEL)                                   \
 220   if (FILL == NULL && (N) != 0 && ! need_pass_2 && subseg_text_p (now_seg))     \
 221     {                                                                           \
 222       arm_frag_align_code (N, MAX);                                             \
 223       goto LABEL;                                                               \
 224     }
 225
 226 #define DWARF2_LINE_MIN_INSN_LENGTH     2
 227
 228 /* The lr register is r14.  */
 229 #define DWARF2_DEFAULT_RETURN_COLUMN  14
 230
 231 /* Registers are generally saved at negative offsets to the CFA.  */
 232 #define DWARF2_CIE_DATA_ALIGNMENT     (-4)
 233
 234 /* State variables for IT block handling.  */
 235 enum it_state
 236 {
 237   OUTSIDE_IT_BLOCK, MANUAL_IT_BLOCK, AUTOMATIC_IT_BLOCK
 238 };
 239 struct current_it
 240 {
 241   int mask;
 242   enum it_state state;
 243   int cc;
 244   int block_length;
 245   char *insn;
 246   int state_handled;
 247 };
 248
 249 #ifdef OBJ_ELF
 250 # define obj_frob_symbol(sym, punt)     armelf_frob_symbol ((sym), & (punt))
 251 # define md_elf_section_change_hook()   arm_elf_change_section ()
 252 # define md_elf_section_type(str, len)  arm_elf_section_type (str, len)
 253 # define GLOBAL_OFFSET_TABLE_NAME       "_GLOBAL_OFFSET_TABLE_"
 254 # define TC_SEGMENT_INFO_TYPE           struct arm_segment_info_type
 255
 256 /* This is not really an alignment operation, but it's something we
 257    need to do at the same time: whenever we are figuring out the
 258    alignment for data, we should check whether a $d symbol is
 259    necessary.  */
 260 # define md_cons_align(nbytes)          mapping_state (MAP_DATA)
 261
 262 enum mstate
 263 {
 264   MAP_UNDEFINED = 0, /* Must be zero, for seginfo in new sections.  */
 265   MAP_DATA,
 266   MAP_ARM,
 267   MAP_THUMB
 268 };
 269
 270 void mapping_state (enum mstate);
 271
 272 struct arm_segment_info_type
 273 {
 274   enum mstate mapstate;
 275
 276   /* Bit N indicates that an R_ARM_NONE relocation has been output for
 277      __aeabi_unwind_cpp_prN already if set. This enables dependencies to be
 278      emitted only once per section, to save unnecessary bloat.  */
 279   unsigned int marked_pr_dependency;
 280
 281   struct current_it current_it;
 282 };
 283
 284 /* We want .cfi_* pseudo-ops for generating unwind info.  */
 285 #define TARGET_USE_CFIPOP              1
 286
 287 /* CFI hooks.  */
 288 #define tc_regname_to_dw2regnum            tc_arm_regname_to_dw2regnum
 289 #define tc_cfi_frame_initial_instructions  tc_arm_frame_initial_instructions
 290
 291 #else /* Not OBJ_ELF.  */
 292 #define GLOBAL_OFFSET_TABLE_NAME "__GLOBAL_OFFSET_TABLE_"
 293 #endif
 294
 295 #if defined OBJ_ELF || defined OBJ_COFF
 296
 297 # define EXTERN_FORCE_RELOC                     1
 298 # define tc_fix_adjustable(FIX)                 arm_fix_adjustable (FIX)
 299 #endif
 300
 301 #ifdef OBJ_ELF
 302 /* Values passed to md_apply_fix don't include the symbol value.  */
 303 # define MD_APPLY_SYM_VALUE(FIX)                arm_apply_sym_value (FIX)
 304 #endif
 305
 306 #ifdef OBJ_COFF
 307 # define TC_VALIDATE_FIX(FIX, SEGTYPE, LABEL)   arm_validate_fix (FIX)
 308 /* Values passed to md_apply_fix don't include the symbol value.  */
 309 # define MD_APPLY_SYM_VALUE(FIX)                0
 310 #endif
 311
 312 #define MD_PCREL_FROM_SECTION(F,S) md_pcrel_from_section(F,S)
 313
 314 extern long md_pcrel_from_section (struct fix *, segT);
 315 extern void arm_frag_align_code (int, int);
 316 extern void arm_validate_fix (struct fix *);
 317 extern const char * elf32_arm_target_format (void);
 318 extern void arm_elf_change_section (void);
 319 extern int arm_force_relocation (struct fix *);
 320 extern void arm_cleanup (void);
 321 extern void arm_start_line_hook (void);
 322 extern void arm_frob_label (symbolS *);
 323 extern int arm_data_in_code (void);
 324 extern char * arm_canonicalize_symbol_name (char *);
 325 extern void arm_adjust_symtab (void);
 326 extern void armelf_frob_symbol (symbolS *, int *);
 327 extern void cons_fix_new_arm (fragS *, int, int, expressionS *);
 328 extern void arm_init_frag (struct frag *, int);
 329 extern void arm_handle_align (struct frag *);
 330 extern bfd_boolean arm_fix_adjustable (struct fix *);
 331 extern int arm_elf_section_type (const char *, size_t);
 332 extern int tc_arm_regname_to_dw2regnum (char *regname);
 333 extern void tc_arm_frame_initial_instructions (void);
 334
 335 #ifdef TE_PE
 336
 337 #define O_secrel O_md1
 338
 339 #define TC_DWARF2_EMIT_OFFSET  tc_pe_dwarf2_emit_offset
 340 void tc_pe_dwarf2_emit_offset (symbolS *, unsigned int);
 341
 342 #endif /* TE_PE */
 343
 344 #ifdef OBJ_ELF
 345 #define CONVERT_SYMBOLIC_ATTRIBUTE(name) arm_convert_symbolic_attribute (name)
 346 extern int arm_convert_symbolic_attribute (const char *);
 347 extern int arm_apply_sym_value (struct fix *);
 348 #endif