gas/config/tc-arm.h

   1 /* This file is tc-arm.h
   2    Copyright (C) 1994-2021 Free Software Foundation, Inc.
   3    Contributed by Richard Earnshaw (rwe@pegasus.esprit.ec.org)
   4         Modified by David Taylor (dtaylor@armltd.co.uk)
   5
   6    This file is part of GAS, the GNU Assembler.
   7
   8    GAS is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3, or (at your option)
  11    any later version.
  12
  13    GAS is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with GAS; see the file COPYING.  If not, write to the Free
  20    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  21    02110-1301, USA.  */
  22
  23 #define TC_ARM 1
  24
  25 #ifndef TARGET_BYTES_BIG_ENDIAN
  26 #define TARGET_BYTES_BIG_ENDIAN 0
  27 #endif
  28
  29 #define WORKING_DOT_WORD
  30
  31 #define COFF_MAGIC      ARMMAGIC
  32 #define TARGET_ARCH     bfd_arch_arm
  33
  34 #define DIFF_EXPR_OK
  35
  36 #ifdef  LITTLE_ENDIAN
  37 #undef  LITTLE_ENDIAN
  38 #endif
  39
  40 #ifdef  BIG_ENDIAN
  41 #undef  BIG_ENDIAN
  42 #endif
  43
  44 #define LITTLE_ENDIAN   1234
  45 #define BIG_ENDIAN      4321
  46
  47 struct fix;
  48
  49 #if defined OBJ_COFF
  50 # define ARM_BI_ENDIAN
  51 # if defined TE_PE
  52 #  if defined TE_WINCE
  53 #   define TARGET_FORMAT (target_big_endian ? "pe-arm-wince-big" : "pe-arm-wince-little")
  54 #  else
  55 #   define TARGET_FORMAT (target_big_endian ? "pe-arm-big" : "pe-arm-little")
  56 #  endif
  57 # else
  58 #  define TARGET_FORMAT (target_big_endian ? "coff-arm-big" : "coff-arm-little")
  59 # endif
  60 #elif defined OBJ_ELF
  61 # define ARM_BI_ENDIAN
  62 # define TARGET_FORMAT  elf32_arm_target_format ()
  63 #endif
  64
  65 /* We support double slash line-comments for compatibility with the ARM AArch64 Assembler.  */
  66 #define DOUBLESLASH_LINE_COMMENTS
  67
  68 /* We conditionally support labels without a colon.  */
  69 #define LABELS_WITHOUT_COLONS codecomposer_syntax
  70 extern bfd_boolean codecomposer_syntax;
  71
  72 #define tc_symbol_chars arm_symbol_chars
  73 extern const char arm_symbol_chars[];
  74
  75 #define TC_FORCE_RELOCATION(FIX) arm_force_relocation (FIX)
  76
  77 extern unsigned int arm_frag_max_var (struct frag *);
  78 #define md_frag_max_var arm_frag_max_var
  79
  80 #define md_relax_frag(segment, fragp, stretch) \
  81   arm_relax_frag (segment, fragp, stretch)
  82 extern int arm_relax_frag (asection *, struct frag *, long);
  83
  84 #define md_optimize_expr(l,o,r)         arm_optimize_expr (l, o, r)
  85 extern int arm_optimize_expr (expressionS *, operatorT, expressionS *);
  86
  87 #define md_cleanup() arm_cleanup ()
  88
  89 #define md_start_line_hook() arm_start_line_hook ()
  90
  91 #define TC_START_LABEL_WITHOUT_COLON(NUL_CHAR, NEXT_CHAR) \
  92   tc_start_label_without_colon ()
  93 extern bfd_boolean tc_start_label_without_colon (void);
  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
 105 #define md_post_relax_hook              arm_md_post_relax ()
 106 extern void arm_md_post_relax (void);
 107 #endif
 108
 109 /* NOTE: The fake label creation in stabs.c:s_stab_generic() has
 110    deliberately not been updated to mark assembler created stabs
 111    symbols as Thumb.  */
 112
 113 #define TC_FIX_TYPE int
 114 #define TC_INIT_FIX_DATA(FIX) ((FIX)->tc_fix_data = 0)
 115
 116 /* We need to keep some local information on symbols.  */
 117
 118 #define TC_SYMFIELD_TYPE        unsigned int
 119 #define ARM_GET_FLAG(s)         (*symbol_get_tc (s))
 120 #define ARM_SET_FLAG(s,v)       (*symbol_get_tc (s) |= (v))
 121 #define ARM_RESET_FLAG(s,v)     (*symbol_get_tc (s) &= ~(v))
 122
 123 #define ARM_FLAG_THUMB          (1 << 0)        /* The symbol is a Thumb symbol rather than an Arm symbol.  */
 124 #define ARM_FLAG_INTERWORK      (1 << 1)        /* The symbol is attached to code that supports interworking.  */
 125 #define THUMB_FLAG_FUNC         (1 << 2)        /* The symbol is attached to the start of a Thumb function.  */
 126
 127 #define ARM_IS_THUMB(s)         (ARM_GET_FLAG (s) & ARM_FLAG_THUMB)
 128 #define ARM_IS_INTERWORK(s)     (ARM_GET_FLAG (s) & ARM_FLAG_INTERWORK)
 129
 130 #ifdef OBJ_ELF
 131
 132 /* For ELF objects THUMB_IS_FUNC is inferred from
 133    ARM_IS_THUMB and the function type.  */
 134 #define THUMB_IS_FUNC(s)                                        \
 135   ((s) != NULL                                                  \
 136    && ((arm_is_eabi ()                                          \
 137         && (ARM_IS_THUMB (s))                                   \
 138         && (symbol_get_bfdsym (s)->flags & BSF_FUNCTION))       \
 139        || (ARM_GET_FLAG (s) & THUMB_FLAG_FUNC)))
 140
 141 #define ARM_IS_FUNC(s)                                  \
 142   (((s) != NULL                                         \
 143     && arm_is_eabi ()                                   \
 144     && !(ARM_IS_THUMB (s))                              \
 145     /* && !(THUMB_FLAG_FUNC & ARM_GET_FLAG (s)) \ */    \
 146     && (symbol_get_bfdsym (s)->flags & BSF_FUNCTION)))
 147
 148
 149 #else
 150
 151 #define THUMB_IS_FUNC(s)        ((s) && ARM_GET_FLAG (s) & THUMB_FLAG_FUNC)
 152 #define ARM_IS_FUNC(s)          (!THUMB_IS_FUNC (s) \
 153                                  && (s) && (symbol_get_bfdsym (s)->flags & BSF_FUNCTION))
 154 #endif
 155
 156 #define ARM_SET_THUMB(s,t)      ((t) ? ARM_SET_FLAG (s, ARM_FLAG_THUMB)     : ARM_RESET_FLAG (s, ARM_FLAG_THUMB))
 157 #define ARM_SET_INTERWORK(s,t)  ((t) ? ARM_SET_FLAG (s, ARM_FLAG_INTERWORK) : ARM_RESET_FLAG (s, ARM_FLAG_INTERWORK))
 158 #define THUMB_SET_FUNC(s,t)     ((t) ? ARM_SET_FLAG (s, THUMB_FLAG_FUNC)    : ARM_RESET_FLAG (s, THUMB_FLAG_FUNC))
 159
 160 void arm_copy_symbol_attributes (symbolS *, symbolS *);
 161
 162 #ifndef TC_COPY_SYMBOL_ATTRIBUTES
 163 #define TC_COPY_SYMBOL_ATTRIBUTES(DEST, SRC) \
 164   (arm_copy_symbol_attributes (DEST, SRC))
 165 #endif
 166
 167 #define TC_START_LABEL(STR, NUL_CHAR, NEXT_CHAR)                        \
 168   (NEXT_CHAR == ':' || (NEXT_CHAR == '/' && arm_data_in_code ()))
 169 #define tc_canonicalize_symbol_name(str) arm_canonicalize_symbol_name (str);
 170 #define obj_adjust_symtab()              arm_adjust_symtab ()
 171
 172 #define LISTING_HEADER "ARM GAS "
 173
 174 #define OPTIONAL_REGISTER_PREFIX '%'
 175
 176 #define LOCAL_LABEL(name)  (name[0] == '.' && name[1] == 'L')
 177 #define LOCAL_LABELS_FB    1
 178
 179 /* This expression evaluates to true if the relocation is for a local
 180    object for which we still want to do the relocation at runtime.
 181    False if we are willing to perform this relocation while building
 182    the .o file.  GOTOFF does not need to be checked here because it is
 183    not pcrel.  I am not sure if some of the others are ever used with
 184    pcrel, but it is easier to be safe than sorry.  */
 185
 186 #define TC_FORCE_RELOCATION_LOCAL(FIX)                  \
 187   (GENERIC_FORCE_RELOCATION_LOCAL (FIX)                 \
 188    || (FIX)->fx_r_type == BFD_RELOC_ARM_GOT32           \
 189    || (FIX)->fx_r_type == BFD_RELOC_32                  \
 190    || ((FIX)->fx_addsy != NULL                          \
 191        && S_IS_WEAK ((FIX)->fx_addsy)))
 192
 193 /* Force output of R_ARM_REL32 relocations against thumb function symbols.
 194    This is needed to ensure the low bit is handled correctly.  */
 195 #define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG)  \
 196   (GENERIC_FORCE_RELOCATION_SUB_SAME (FIX, SEG) \
 197    || THUMB_IS_FUNC ((FIX)->fx_addsy))
 198
 199 #define TC_FORCE_RELOCATION_ABS(FIX)                    \
 200   (((FIX)->fx_pcrel                                     \
 201     && (FIX)->fx_r_type != BFD_RELOC_32                 \
 202     && (FIX)->fx_r_type != BFD_RELOC_ARM_GOT32)         \
 203    || TC_FORCE_RELOCATION(FIX))
 204
 205 #define TC_CONS_FIX_NEW cons_fix_new_arm
 206
 207 #define MAX_MEM_ALIGNMENT_BYTES    6
 208 #define MAX_MEM_FOR_RS_ALIGN_CODE ((1 << MAX_MEM_ALIGNMENT_BYTES) - 1)
 209
 210 /* For frags in code sections we need to record whether they contain
 211    ARM code or THUMB code.  This is that if they have to be aligned,
 212    they can contain the correct type of no-op instruction.  */
 213 struct arm_frag_type
 214 {
 215   int thumb_mode;
 216 #ifdef OBJ_ELF
 217   /* If there is a mapping symbol at offset 0 in this frag,
 218      it will be saved in FIRST_MAP.  If there are any mapping
 219      symbols in this frag, the last one will be saved in
 220      LAST_MAP.  */
 221   symbolS *first_map, *last_map;
 222 #endif
 223 };
 224
 225 static inline int
 226 arm_min (int am_p1, int am_p2)
 227 {
 228   return am_p1 < am_p2 ? am_p1 : am_p2;
 229 }
 230
 231 #define TC_FRAG_TYPE            struct arm_frag_type
 232 #define TC_FRAG_INIT(fragp, max_bytes) arm_init_frag (fragp, max_bytes)
 233 #define TC_ALIGN_ZERO_IS_DEFAULT 1
 234 #define HANDLE_ALIGN(fragp)     arm_handle_align (fragp)
 235 /* PR gas/19276: COFF/PE segment alignment is already handled in coff_frob_section().  */
 236 #ifndef TE_PE
 237 #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN)                         \
 238   ((!(FRCHAIN)->frch_next && subseg_text_p (SEG))               \
 239    ? arm_min (2, get_recorded_alignment (SEG)) : 0)
 240 #endif
 241
 242 #define md_do_align(N, FILL, LEN, MAX, LABEL)                                   \
 243   if (FILL == NULL && (N) != 0 && ! need_pass_2 && subseg_text_p (now_seg))     \
 244     {                                                                           \
 245       arm_frag_align_code (N, MAX);                                             \
 246       goto LABEL;                                                               \
 247     }
 248
 249 #define DWARF2_LINE_MIN_INSN_LENGTH     2
 250
 251 /* The lr register is r14.  */
 252 #define DWARF2_DEFAULT_RETURN_COLUMN  14
 253
 254 /* Registers are generally saved at negative offsets to the CFA.  */
 255 #define DWARF2_CIE_DATA_ALIGNMENT     (-4)
 256
 257 /* State variables for predication block handling.  */
 258 enum pred_state
 259 {
 260   OUTSIDE_PRED_BLOCK, MANUAL_PRED_BLOCK, AUTOMATIC_PRED_BLOCK
 261 };
 262 enum pred_type {
 263   SCALAR_PRED, VECTOR_PRED
 264 };
 265 struct current_pred
 266 {
 267   int mask;
 268   enum pred_state state;
 269   int cc;
 270   int block_length;
 271   char *insn;
 272   int state_handled;
 273   int warn_deprecated;
 274   int insn_cond;
 275   enum pred_type type;
 276 };
 277
 278 #ifdef OBJ_ELF
 279 # define obj_frob_symbol(sym, punt)     armelf_frob_symbol ((sym), & (punt))
 280 # define md_elf_section_change_hook()   arm_elf_change_section ()
 281 # define md_elf_section_type(str, len)  arm_elf_section_type (str, len)
 282 # define GLOBAL_OFFSET_TABLE_NAME       "_GLOBAL_OFFSET_TABLE_"
 283 # define TC_SEGMENT_INFO_TYPE           struct arm_segment_info_type
 284
 285 /* This is not really an alignment operation, but it's something we
 286    need to do at the same time: whenever we are figuring out the
 287    alignment for data, we should check whether a $d symbol is
 288    necessary.  */
 289 # define md_cons_align(nbytes)          mapping_state (MAP_DATA)
 290
 291 enum mstate
 292 {
 293   MAP_UNDEFINED = 0, /* Must be zero, for seginfo in new sections.  */
 294   MAP_DATA,
 295   MAP_ARM,
 296   MAP_THUMB
 297 };
 298
 299 void mapping_state (enum mstate);
 300
 301 struct arm_segment_info_type
 302 {
 303   enum mstate mapstate;
 304
 305   /* Bit N indicates that an R_ARM_NONE relocation has been output for
 306      __aeabi_unwind_cpp_prN already if set. This enables dependencies to be
 307      emitted only once per section, to save unnecessary bloat.  */
 308   unsigned int marked_pr_dependency;
 309
 310   struct current_pred current_pred;
 311 };
 312
 313 /* We want .cfi_* pseudo-ops for generating unwind info.  */
 314 #define TARGET_USE_CFIPOP              1
 315
 316 /* CFI hooks.  */
 317 #define tc_regname_to_dw2regnum            tc_arm_regname_to_dw2regnum
 318 #define tc_cfi_frame_initial_instructions  tc_arm_frame_initial_instructions
 319
 320 #else /* Not OBJ_ELF.  */
 321 #define GLOBAL_OFFSET_TABLE_NAME "__GLOBAL_OFFSET_TABLE_"
 322 #endif
 323
 324 #if defined OBJ_ELF || defined OBJ_COFF
 325
 326 # define EXTERN_FORCE_RELOC                     1
 327 # define tc_fix_adjustable(FIX)                 arm_fix_adjustable (FIX)
 328 #endif
 329
 330 #ifdef OBJ_ELF
 331 /* Values passed to md_apply_fix don't include the symbol value.  */
 332 # define MD_APPLY_SYM_VALUE(FIX)                arm_apply_sym_value (FIX, this_segment)
 333 #endif
 334
 335 #ifdef OBJ_COFF
 336 # define TC_VALIDATE_FIX(FIX, SEGTYPE, LABEL)   arm_validate_fix (FIX)
 337 /* Values passed to md_apply_fix don't include the symbol value.  */
 338 # define MD_APPLY_SYM_VALUE(FIX)                0
 339 #endif
 340
 341 #define MD_PCREL_FROM_SECTION(F,S) md_pcrel_from_section(F,S)
 342
 343 extern void arm_frag_align_code (int, int);
 344 extern void arm_validate_fix (struct fix *);
 345 extern const char * elf32_arm_target_format (void);
 346 extern void arm_elf_change_section (void);
 347 extern int arm_force_relocation (struct fix *);
 348 extern void arm_cleanup (void);
 349 extern void arm_start_line_hook (void);
 350 extern void arm_frob_label (symbolS *);
 351 extern int arm_data_in_code (void);
 352 extern char * arm_canonicalize_symbol_name (char *);
 353 extern void arm_adjust_symtab (void);
 354 extern void armelf_frob_symbol (symbolS *, int *);
 355 extern void cons_fix_new_arm (fragS *, int, int, expressionS *,
 356                               bfd_reloc_code_real_type);
 357 extern void arm_init_frag (struct frag *, int);
 358 extern void arm_handle_align (struct frag *);
 359 extern bfd_boolean arm_fix_adjustable (struct fix *);
 360 extern int arm_elf_section_type (const char *, size_t);
 361 extern int tc_arm_regname_to_dw2regnum (char *regname);
 362 extern void tc_arm_frame_initial_instructions (void);
 363
 364 #ifdef TE_PE
 365
 366 #define O_secrel O_md1
 367
 368 #define TC_DWARF2_EMIT_OFFSET  tc_pe_dwarf2_emit_offset
 369 void tc_pe_dwarf2_emit_offset (symbolS *, unsigned int);
 370
 371 #endif /* TE_PE */
 372
 373 #ifdef OBJ_ELF
 374 #define CONVERT_SYMBOLIC_ATTRIBUTE(name) arm_convert_symbolic_attribute (name)
 375 extern int arm_convert_symbolic_attribute (const char *);
 376 extern int arm_apply_sym_value (struct fix *, segT);
 377 #endif
 378
 379 #define tc_comment_chars arm_comment_chars
 380 extern char arm_comment_chars[];
 381
 382 #define tc_line_separator_chars arm_line_separator_chars
 383 extern char arm_line_separator_chars[];
 384
 385 #define TC_EQUAL_IN_INSN(c, s) arm_tc_equal_in_insn ((c), (s))
 386 extern bfd_boolean arm_tc_equal_in_insn (int, char *);
 387
 388 #define TC_LARGEST_EXPONENT_IS_NORMAL(PRECISION) \
 389         arm_is_largest_exponent_ok ((PRECISION))
 390 int arm_is_largest_exponent_ok (int precision);