gas/config/tc-arm.h

   1 /* This file is tc-arm.h
   2    Copyright (C) 1994-2023 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 TARGET_ARCH     bfd_arch_arm
  32
  33 #define DIFF_EXPR_OK
  34
  35 #ifdef  LITTLE_ENDIAN
  36 #undef  LITTLE_ENDIAN
  37 #endif
  38
  39 #ifdef  BIG_ENDIAN
  40 #undef  BIG_ENDIAN
  41 #endif
  42
  43 #define LITTLE_ENDIAN   1234
  44 #define BIG_ENDIAN      4321
  45
  46 struct fix;
  47
  48 #if defined OBJ_COFF
  49 # define ARM_BI_ENDIAN
  50 # if defined TE_PE
  51 #  if defined TE_WINCE
  52 #   define TARGET_FORMAT (target_big_endian ? "pe-arm-wince-big" : "pe-arm-wince-little")
  53 #  else
  54 #   define TARGET_FORMAT (target_big_endian ? "pe-arm-big" : "pe-arm-little")
  55 #  endif
  56 # else
  57 #  define TARGET_FORMAT (target_big_endian ? "coff-arm-big" : "coff-arm-little")
  58 # endif
  59 #elif defined OBJ_ELF
  60 # define ARM_BI_ENDIAN
  61 # define TARGET_FORMAT  elf32_arm_target_format ()
  62 #endif
  63
  64 /* We support double slash line-comments for compatibility with the ARM AArch64 Assembler.  */
  65 #define DOUBLESLASH_LINE_COMMENTS
  66
  67 /* We conditionally support labels without a colon.  */
  68 #define LABELS_WITHOUT_COLONS codecomposer_syntax
  69 extern bool codecomposer_syntax;
  70
  71 #define tc_symbol_chars arm_symbol_chars
  72 extern const char arm_symbol_chars[];
  73
  74 #define TC_FORCE_RELOCATION(FIX) arm_force_relocation (FIX)
  75
  76 extern unsigned int arm_frag_max_var (struct frag *);
  77 #define md_frag_max_var arm_frag_max_var
  78
  79 #define md_relax_frag(segment, fragp, stretch) \
  80   arm_relax_frag (segment, fragp, stretch)
  81 extern int arm_relax_frag (asection *, struct frag *, long);
  82
  83 #define md_optimize_expr(l,o,r)         arm_optimize_expr (l, o, r)
  84 extern bool arm_optimize_expr (expressionS *, operatorT, expressionS *);
  85
  86 #define md_cleanup() arm_cleanup ()
  87
  88 #define md_start_line_hook() arm_start_line_hook ()
  89
  90 #define TC_START_LABEL_WITHOUT_COLON(NUL_CHAR, NEXT_CHAR) \
  91   tc_start_label_without_colon ()
  92 extern bool tc_start_label_without_colon (void);
  93
  94 #define tc_frob_label(S) arm_frob_label (S)
  95
  96 /* We also need to mark assembler created symbols:  */
  97 #define tc_frob_fake_label(S) arm_frob_label (S)
  98
  99 #ifdef OBJ_ELF
 100 #define md_finish arm_md_finish
 101 extern void arm_md_finish (void);
 102 bool arm_is_eabi (void);
 103
 104 #define md_post_relax_hook              arm_md_post_relax ()
 105 extern void arm_md_post_relax (void);
 106 #endif
 107
 108 /* NOTE: The fake label creation in stabs.c:s_stab_generic() has
 109    deliberately not been updated to mark assembler created stabs
 110    symbols as Thumb.  */
 111
 112 #define TC_FIX_TYPE int
 113 #define TC_INIT_FIX_DATA(FIX) ((FIX)->tc_fix_data = 0)
 114
 115 /* We need to keep some local information on symbols.  */
 116
 117 #define TC_SYMFIELD_TYPE        unsigned int
 118 #define ARM_GET_FLAG(s)         (*symbol_get_tc (s))
 119 #define ARM_SET_FLAG(s,v)       (*symbol_get_tc (s) |= (v))
 120 #define ARM_RESET_FLAG(s,v)     (*symbol_get_tc (s) &= ~(v))
 121
 122 #define ARM_FLAG_THUMB          (1 << 0)        /* The symbol is a Thumb symbol rather than an Arm symbol.  */
 123 #define ARM_FLAG_INTERWORK      (1 << 1)        /* The symbol is attached to code that supports interworking.  */
 124 #define THUMB_FLAG_FUNC         (1 << 2)        /* The symbol is attached to the start of a Thumb function.  */
 125
 126 #define ARM_IS_THUMB(s)         (ARM_GET_FLAG (s) & ARM_FLAG_THUMB)
 127 #define ARM_IS_INTERWORK(s)     (ARM_GET_FLAG (s) & ARM_FLAG_INTERWORK)
 128
 129 #ifdef OBJ_ELF
 130
 131 /* For ELF objects THUMB_IS_FUNC is inferred from
 132    ARM_IS_THUMB and the function type.  */
 133 #define THUMB_IS_FUNC(s)                                        \
 134   ((s) != NULL                                                  \
 135    && ((arm_is_eabi ()                                          \
 136         && (ARM_IS_THUMB (s))                                   \
 137         && (symbol_get_bfdsym (s)->flags & BSF_FUNCTION))       \
 138        || (ARM_GET_FLAG (s) & THUMB_FLAG_FUNC)))
 139
 140 #define ARM_IS_FUNC(s)                                  \
 141   (((s) != NULL                                         \
 142     && arm_is_eabi ()                                   \
 143     && !(ARM_IS_THUMB (s))                              \
 144     /* && !(THUMB_FLAG_FUNC & ARM_GET_FLAG (s)) \ */    \
 145     && (symbol_get_bfdsym (s)->flags & BSF_FUNCTION)))
 146
 147
 148 #else
 149
 150 #define THUMB_IS_FUNC(s)        ((s) && ARM_GET_FLAG (s) & THUMB_FLAG_FUNC)
 151 #define ARM_IS_FUNC(s)          (!THUMB_IS_FUNC (s) \
 152                                  && (s) && (symbol_get_bfdsym (s)->flags & BSF_FUNCTION))
 153 #endif
 154
 155 #define ARM_SET_THUMB(s,t)      ((t) ? ARM_SET_FLAG (s, ARM_FLAG_THUMB)     : ARM_RESET_FLAG (s, ARM_FLAG_THUMB))
 156 #define ARM_SET_INTERWORK(s,t)  ((t) ? ARM_SET_FLAG (s, ARM_FLAG_INTERWORK) : ARM_RESET_FLAG (s, ARM_FLAG_INTERWORK))
 157 #define THUMB_SET_FUNC(s,t)     ((t) ? ARM_SET_FLAG (s, THUMB_FLAG_FUNC)    : ARM_RESET_FLAG (s, THUMB_FLAG_FUNC))
 158
 159 void arm_copy_symbol_attributes (symbolS *, symbolS *);
 160
 161 #ifndef TC_COPY_SYMBOL_ATTRIBUTES
 162 #define TC_COPY_SYMBOL_ATTRIBUTES(DEST, SRC) \
 163   (arm_copy_symbol_attributes (DEST, SRC))
 164 #endif
 165
 166 #define TC_START_LABEL(STR, NUL_CHAR, NEXT_CHAR)                        \
 167   (NEXT_CHAR == ':' || (NEXT_CHAR == '/' && arm_data_in_code ()))
 168 #define tc_canonicalize_symbol_name(str) arm_canonicalize_symbol_name (str);
 169 #define obj_adjust_symtab()              arm_adjust_symtab ()
 170
 171 #define LISTING_HEADER "ARM GAS "
 172
 173 #define OPTIONAL_REGISTER_PREFIX '%'
 174
 175 #define LOCAL_LABEL(name)  (name[0] == '.' && name[1] == 'L')
 176 #define LOCAL_LABELS_FB    1
 177
 178 /* This expression evaluates to true if the relocation is for a local
 179    object for which we still want to do the relocation at runtime.
 180    False if we are willing to perform this relocation while building
 181    the .o file.  GOTOFF does not need to be checked here because it is
 182    not pcrel.  I am not sure if some of the others are ever used with
 183    pcrel, but it is easier to be safe than sorry.  */
 184
 185 #define TC_FORCE_RELOCATION_LOCAL(FIX)                  \
 186   (GENERIC_FORCE_RELOCATION_LOCAL (FIX)                 \
 187    || (FIX)->fx_r_type == BFD_RELOC_ARM_GOT32           \
 188    || (FIX)->fx_r_type == BFD_RELOC_32                  \
 189    || ((FIX)->fx_addsy != NULL                          \
 190        && S_IS_WEAK ((FIX)->fx_addsy)))
 191
 192 /* Force output of R_ARM_REL32 relocations against thumb function symbols.
 193    This is needed to ensure the low bit is handled correctly.  */
 194 #define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG)  \
 195   (GENERIC_FORCE_RELOCATION_SUB_SAME (FIX, SEG) \
 196    || THUMB_IS_FUNC ((FIX)->fx_addsy))
 197
 198 #define TC_FORCE_RELOCATION_ABS(FIX)                    \
 199   (((FIX)->fx_pcrel                                     \
 200     && (FIX)->fx_r_type != BFD_RELOC_32                 \
 201     && (FIX)->fx_r_type != BFD_RELOC_ARM_GOT32)         \
 202    || TC_FORCE_RELOCATION(FIX))
 203
 204 #define TC_CONS_FIX_NEW cons_fix_new_arm
 205
 206 #define MAX_MEM_ALIGNMENT_BYTES    6
 207 #define MAX_MEM_FOR_RS_ALIGN_CODE ((1 << MAX_MEM_ALIGNMENT_BYTES) - 1)
 208
 209 /* For frags in code sections we need to record whether they contain
 210    ARM code or THUMB code.  This is that if they have to be aligned,
 211    they can contain the correct type of no-op instruction.  */
 212 struct arm_frag_type
 213 {
 214   int thumb_mode;
 215 #ifdef OBJ_ELF
 216   /* If there is a mapping symbol at offset 0 in this frag,
 217      it will be saved in FIRST_MAP.  If there are any mapping
 218      symbols in this frag, the last one will be saved in
 219      LAST_MAP.  */
 220   symbolS *first_map, *last_map;
 221 #endif
 222 };
 223
 224 static inline int
 225 arm_min (int am_p1, int am_p2)
 226 {
 227   return am_p1 < am_p2 ? am_p1 : am_p2;
 228 }
 229
 230 #define TC_FRAG_TYPE            struct arm_frag_type
 231 #define TC_FRAG_INIT(fragp, max_bytes) arm_init_frag (fragp, max_bytes)
 232 #define TC_ALIGN_ZERO_IS_DEFAULT 1
 233 #define HANDLE_ALIGN(fragp)     arm_handle_align (fragp)
 234 /* PR gas/19276: COFF/PE segment alignment is already handled in coff_frob_section().  */
 235 #ifndef TE_PE
 236 #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN)                         \
 237   ((!(FRCHAIN)->frch_next && subseg_text_p (SEG))               \
 238    ? arm_min (2, get_recorded_alignment (SEG)) : 0)
 239 #endif
 240
 241 #define md_do_align(N, FILL, LEN, MAX, LABEL)                                   \
 242   if (FILL == NULL && (N) != 0 && ! need_pass_2 && subseg_text_p (now_seg))     \
 243     {                                                                           \
 244       arm_frag_align_code (N, MAX);                                             \
 245       goto LABEL;                                                               \
 246     }
 247
 248 #define DWARF2_LINE_MIN_INSN_LENGTH     2
 249
 250 /* The lr register is r14.  */
 251 #define DWARF2_DEFAULT_RETURN_COLUMN  14
 252
 253 /* Registers are generally saved at negative offsets to the CFA.  */
 254 #define DWARF2_CIE_DATA_ALIGNMENT     (-4)
 255
 256 /* State variables for predication block handling.  */
 257 enum pred_state
 258 {
 259   OUTSIDE_PRED_BLOCK, MANUAL_PRED_BLOCK, AUTOMATIC_PRED_BLOCK
 260 };
 261 enum pred_type {
 262   SCALAR_PRED, VECTOR_PRED
 263 };
 264 struct current_pred
 265 {
 266   int mask;
 267   enum pred_state state;
 268   int cc;
 269   int block_length;
 270   char *insn;
 271   int state_handled;
 272   int warn_deprecated;
 273   int insn_cond;
 274   enum pred_type type;
 275 };
 276
 277 #ifdef OBJ_ELF
 278 # define obj_frob_symbol(sym, punt)     armelf_frob_symbol ((sym), & (punt))
 279 # define md_elf_section_change_hook()   arm_elf_change_section ()
 280 # define md_elf_section_type(str, len)  arm_elf_section_type (str, len)
 281 # define GLOBAL_OFFSET_TABLE_NAME       "_GLOBAL_OFFSET_TABLE_"
 282 # define TC_SEGMENT_INFO_TYPE           struct arm_segment_info_type
 283
 284 /* This is not really an alignment operation, but it's something we
 285    need to do at the same time: whenever we are figuring out the
 286    alignment for data, we should check whether a $d symbol is
 287    necessary.  */
 288 # define md_cons_align(nbytes)          mapping_state (MAP_DATA)
 289
 290 enum mstate
 291 {
 292   MAP_UNDEFINED = 0, /* Must be zero, for seginfo in new sections.  */
 293   MAP_DATA,
 294   MAP_ARM,
 295   MAP_THUMB
 296 };
 297
 298 void mapping_state (enum mstate);
 299
 300 struct arm_segment_info_type
 301 {
 302   enum mstate mapstate;
 303
 304   /* Bit N indicates that an R_ARM_NONE relocation has been output for
 305      __aeabi_unwind_cpp_prN already if set. This enables dependencies to be
 306      emitted only once per section, to save unnecessary bloat.  */
 307   unsigned int marked_pr_dependency;
 308
 309   struct current_pred current_pred;
 310 };
 311
 312 /* We want .cfi_* pseudo-ops for generating unwind info.  */
 313 #define TARGET_USE_CFIPOP              1
 314
 315 /* CFI hooks.  */
 316 #define tc_regname_to_dw2regnum            tc_arm_regname_to_dw2regnum
 317 #define tc_cfi_frame_initial_instructions  tc_arm_frame_initial_instructions
 318
 319 #else /* Not OBJ_ELF.  */
 320 #define GLOBAL_OFFSET_TABLE_NAME "__GLOBAL_OFFSET_TABLE_"
 321 #endif
 322
 323 #if defined OBJ_ELF || defined OBJ_COFF
 324
 325 # define EXTERN_FORCE_RELOC                     1
 326 # define tc_fix_adjustable(FIX)                 arm_fix_adjustable (FIX)
 327 #endif
 328
 329 #ifdef OBJ_ELF
 330 /* Values passed to md_apply_fix don't include the symbol value.  */
 331 # define MD_APPLY_SYM_VALUE(FIX)                arm_apply_sym_value (FIX, this_segment)
 332 #endif
 333
 334 #ifdef OBJ_COFF
 335 # define TC_VALIDATE_FIX(FIX, SEGTYPE, LABEL)   arm_validate_fix (FIX)
 336 /* Values passed to md_apply_fix don't include the symbol value.  */
 337 # define MD_APPLY_SYM_VALUE(FIX)                0
 338 #endif
 339
 340 #define MD_PCREL_FROM_SECTION(F,S) md_pcrel_from_section(F,S)
 341
 342 extern void arm_frag_align_code (int, int);
 343 extern void arm_validate_fix (struct fix *);
 344 extern const char * elf32_arm_target_format (void);
 345 extern void arm_elf_change_section (void);
 346 extern int arm_force_relocation (struct fix *);
 347 extern void arm_cleanup (void);
 348 extern void arm_start_line_hook (void);
 349 extern void arm_frob_label (symbolS *);
 350 extern bool arm_data_in_code (void);
 351 extern char * arm_canonicalize_symbol_name (char *);
 352 extern void arm_adjust_symtab (void);
 353 extern void armelf_frob_symbol (symbolS *, int *);
 354 extern void cons_fix_new_arm (fragS *, int, int, expressionS *,
 355                               bfd_reloc_code_real_type);
 356 extern void arm_init_frag (struct frag *, int);
 357 extern void arm_handle_align (struct frag *);
 358 extern bool arm_fix_adjustable (struct fix *);
 359 extern int arm_elf_section_type (const char *, size_t);
 360 extern int tc_arm_regname_to_dw2regnum (char *regname);
 361 extern void tc_arm_frame_initial_instructions (void);
 362
 363 #ifdef TE_PE
 364
 365 #define O_secrel O_md1
 366
 367 #define TC_DWARF2_EMIT_OFFSET  tc_pe_dwarf2_emit_offset
 368 void tc_pe_dwarf2_emit_offset (symbolS *, unsigned int);
 369
 370 #endif /* TE_PE */
 371
 372 #ifdef OBJ_ELF
 373 #define CONVERT_SYMBOLIC_ATTRIBUTE(name) arm_convert_symbolic_attribute (name)
 374 extern int arm_convert_symbolic_attribute (const char *);
 375 extern int arm_apply_sym_value (struct fix *, segT);
 376 #endif
 377
 378 #define tc_comment_chars arm_comment_chars
 379 extern char arm_comment_chars[];
 380
 381 #define tc_line_separator_chars arm_line_separator_chars
 382 extern char arm_line_separator_chars[];
 383
 384 #define TC_EQUAL_IN_INSN(c, s) arm_tc_equal_in_insn ((c), (s))
 385 extern bool arm_tc_equal_in_insn (int, char *);
 386
 387 #define TC_LARGEST_EXPONENT_IS_NORMAL(PRECISION) \
 388         arm_is_largest_exponent_ok ((PRECISION))
 389 int arm_is_largest_exponent_ok (int precision);