opcodes/bpf-asm.c

   1 /* DO NOT EDIT!  -*- buffer-read-only: t -*- vi:set ro:  */
   2 /* Assembler interface for targets using CGEN. -*- C -*-
   3    CGEN: Cpu tools GENerator
   4
   5    THIS FILE IS MACHINE GENERATED WITH CGEN.
   6    - the resultant file is machine generated, cgen-asm.in isn't
   7
   8    Copyright (C) 1996-2019 Free Software Foundation, Inc.
   9
  10    This file is part of libopcodes.
  11
  12    This library is free software; you can redistribute it and/or modify
  13    it under the terms of the GNU General Public License as published by
  14    the Free Software Foundation; either version 3, or (at your option)
  15    any later version.
  16
  17    It is distributed in the hope that it will be useful, but WITHOUT
  18    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  20    License for more details.
  21
  22    You should have received a copy of the GNU General Public License
  23    along with this program; if not, write to the Free Software Foundation, Inc.,
  24    51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
  25
  26
  27 /* ??? Eventually more and more of this stuff can go to cpu-independent files.
  28    Keep that in mind.  */
  29
  30 #include "sysdep.h"
  31 #include <stdio.h>
  32 #include "ansidecl.h"
  33 #include "bfd.h"
  34 #include "symcat.h"
  35 #include "bpf-desc.h"
  36 #include "bpf-opc.h"
  37 #include "opintl.h"
  38 #include "xregex.h"
  39 #include "libiberty.h"
  40 #include "safe-ctype.h"
  41
  42 #undef  min
  43 #define min(a,b) ((a) < (b) ? (a) : (b))
  44 #undef  max
  45 #define max(a,b) ((a) > (b) ? (a) : (b))
  46
  47 static const char * parse_insn_normal
  48   (CGEN_CPU_DESC, const CGEN_INSN *, const char **, CGEN_FIELDS *);
  49 \f
  50 /* -- assembler routines inserted here.  */
  51
  52 /* -- asm.c */
  53
  54 /* Parse a signed 64-bit immediate.  */
  55
  56 static const char *
  57 parse_imm64 (CGEN_CPU_DESC cd,
  58              const char **strp,
  59              int opindex,
  60              int64_t *valuep)
  61 {
  62   bfd_vma value;
  63   enum cgen_parse_operand_result result;
  64   const char *errmsg;
  65
  66   errmsg = (* cd->parse_operand_fn)
  67     (cd, CGEN_PARSE_OPERAND_INTEGER, strp, opindex, BFD_RELOC_NONE,
  68      &result, &value);
  69   if (!errmsg)
  70     *valuep = value;
  71
  72   return errmsg;
  73 }
  74
  75 /* Endianness size operands are integer immediates whose values can be
  76    16, 32 or 64.  */
  77
  78 static const char *
  79 parse_endsize (CGEN_CPU_DESC cd,
  80                const char **strp,
  81                int opindex,
  82                unsigned long *valuep)
  83 {
  84   const char *errmsg;
  85
  86   errmsg = cgen_parse_unsigned_integer (cd, strp, opindex, valuep);
  87   if (errmsg)
  88     return errmsg;
  89
  90   switch (*valuep)
  91     {
  92     case 16:
  93     case 32:
  94     case 64:
  95       break;
  96     default:
  97       return _("expected 16, 32 or 64 in");
  98     }
  99
 100   return NULL;
 101 }
 102
 103 /* Special check to ensure that the right instruction variant is used
 104    for the given endianness induced by the ISA selected in the CPU.
 105    See bpf.cpu for a discussion on how eBPF is really two instruction
 106    sets.  */
 107
 108 int
 109 bpf_cgen_insn_supported (CGEN_CPU_DESC cd, const CGEN_INSN *insn)
 110 {
 111   CGEN_BITSET isas = CGEN_INSN_BITSET_ATTR_VALUE (insn, CGEN_INSN_ISA);
 112
 113   return cgen_bitset_intersect_p (&isas, cd->isas);
 114 }
 115
 116 \f
 117 /* -- dis.c */
 118
 119 const char * bpf_cgen_parse_operand
 120   (CGEN_CPU_DESC, int, const char **, CGEN_FIELDS *);
 121
 122 /* Main entry point for operand parsing.
 123
 124    This function is basically just a big switch statement.  Earlier versions
 125    used tables to look up the function to use, but
 126    - if the table contains both assembler and disassembler functions then
 127      the disassembler contains much of the assembler and vice-versa,
 128    - there's a lot of inlining possibilities as things grow,
 129    - using a switch statement avoids the function call overhead.
 130
 131    This function could be moved into `parse_insn_normal', but keeping it
 132    separate makes clear the interface between `parse_insn_normal' and each of
 133    the handlers.  */
 134
 135 const char *
 136 bpf_cgen_parse_operand (CGEN_CPU_DESC cd,
 137                            int opindex,
 138                            const char ** strp,
 139                            CGEN_FIELDS * fields)
 140 {
 141   const char * errmsg = NULL;
 142   /* Used by scalar operands that still need to be parsed.  */
 143   long junk ATTRIBUTE_UNUSED;
 144
 145   switch (opindex)
 146     {
 147     case BPF_OPERAND_DISP16 :
 148       errmsg = cgen_parse_signed_integer (cd, strp, BPF_OPERAND_DISP16, (long *) (& fields->f_offset16));
 149       break;
 150     case BPF_OPERAND_DISP32 :
 151       errmsg = cgen_parse_signed_integer (cd, strp, BPF_OPERAND_DISP32, (long *) (& fields->f_imm32));
 152       break;
 153     case BPF_OPERAND_DSTBE :
 154       errmsg = cgen_parse_keyword (cd, strp, & bpf_cgen_opval_h_gpr, & fields->f_dstbe);
 155       break;
 156     case BPF_OPERAND_DSTLE :
 157       errmsg = cgen_parse_keyword (cd, strp, & bpf_cgen_opval_h_gpr, & fields->f_dstle);
 158       break;
 159     case BPF_OPERAND_ENDSIZE :
 160       errmsg = parse_endsize (cd, strp, BPF_OPERAND_ENDSIZE, (unsigned long *) (& fields->f_imm32));
 161       break;
 162     case BPF_OPERAND_IMM32 :
 163       errmsg = cgen_parse_signed_integer (cd, strp, BPF_OPERAND_IMM32, (long *) (& fields->f_imm32));
 164       break;
 165     case BPF_OPERAND_IMM64 :
 166       errmsg = parse_imm64 (cd, strp, BPF_OPERAND_IMM64, (int64_t *) (& fields->f_imm64));
 167       break;
 168     case BPF_OPERAND_OFFSET16 :
 169       errmsg = cgen_parse_signed_integer (cd, strp, BPF_OPERAND_OFFSET16, (long *) (& fields->f_offset16));
 170       break;
 171     case BPF_OPERAND_SRCBE :
 172       errmsg = cgen_parse_keyword (cd, strp, & bpf_cgen_opval_h_gpr, & fields->f_srcbe);
 173       break;
 174     case BPF_OPERAND_SRCLE :
 175       errmsg = cgen_parse_keyword (cd, strp, & bpf_cgen_opval_h_gpr, & fields->f_srcle);
 176       break;
 177
 178     default :
 179       /* xgettext:c-format */
 180       opcodes_error_handler
 181         (_("internal error: unrecognized field %d while parsing"),
 182          opindex);
 183       abort ();
 184   }
 185
 186   return errmsg;
 187 }
 188
 189 cgen_parse_fn * const bpf_cgen_parse_handlers[] =
 190 {
 191   parse_insn_normal,
 192 };
 193
 194 void
 195 bpf_cgen_init_asm (CGEN_CPU_DESC cd)
 196 {
 197   bpf_cgen_init_opcode_table (cd);
 198   bpf_cgen_init_ibld_table (cd);
 199   cd->parse_handlers = & bpf_cgen_parse_handlers[0];
 200   cd->parse_operand = bpf_cgen_parse_operand;
 201 #ifdef CGEN_ASM_INIT_HOOK
 202 CGEN_ASM_INIT_HOOK
 203 #endif
 204 }
 205
 206 \f
 207
 208 /* Regex construction routine.
 209
 210    This translates an opcode syntax string into a regex string,
 211    by replacing any non-character syntax element (such as an
 212    opcode) with the pattern '.*'
 213
 214    It then compiles the regex and stores it in the opcode, for
 215    later use by bpf_cgen_assemble_insn
 216
 217    Returns NULL for success, an error message for failure.  */
 218
 219 char *
 220 bpf_cgen_build_insn_regex (CGEN_INSN *insn)
 221 {
 222   CGEN_OPCODE *opc = (CGEN_OPCODE *) CGEN_INSN_OPCODE (insn);
 223   const char *mnem = CGEN_INSN_MNEMONIC (insn);
 224   char rxbuf[CGEN_MAX_RX_ELEMENTS];
 225   char *rx = rxbuf;
 226   const CGEN_SYNTAX_CHAR_TYPE *syn;
 227   int reg_err;
 228
 229   syn = CGEN_SYNTAX_STRING (CGEN_OPCODE_SYNTAX (opc));
 230
 231   /* Mnemonics come first in the syntax string.  */
 232   if (! CGEN_SYNTAX_MNEMONIC_P (* syn))
 233     return _("missing mnemonic in syntax string");
 234   ++syn;
 235
 236   /* Generate a case sensitive regular expression that emulates case
 237      insensitive matching in the "C" locale.  We cannot generate a case
 238      insensitive regular expression because in Turkish locales, 'i' and 'I'
 239      are not equal modulo case conversion.  */
 240
 241   /* Copy the literal mnemonic out of the insn.  */
 242   for (; *mnem; mnem++)
 243     {
 244       char c = *mnem;
 245
 246       if (ISALPHA (c))
 247         {
 248           *rx++ = '[';
 249           *rx++ = TOLOWER (c);
 250           *rx++ = TOUPPER (c);
 251           *rx++ = ']';
 252         }
 253       else
 254         *rx++ = c;
 255     }
 256
 257   /* Copy any remaining literals from the syntax string into the rx.  */
 258   for(; * syn != 0 && rx <= rxbuf + (CGEN_MAX_RX_ELEMENTS - 7 - 4); ++syn)
 259     {
 260       if (CGEN_SYNTAX_CHAR_P (* syn))
 261         {
 262           char c = CGEN_SYNTAX_CHAR (* syn);
 263
 264           switch (c)
 265             {
 266               /* Escape any regex metacharacters in the syntax.  */
 267             case '.': case '[': case '\\':
 268             case '*': case '^': case '$':
 269
 270 #ifdef CGEN_ESCAPE_EXTENDED_REGEX
 271             case '?': case '{': case '}':
 272             case '(': case ')': case '*':
 273             case '|': case '+': case ']':
 274 #endif
 275               *rx++ = '\\';
 276               *rx++ = c;
 277               break;
 278
 279             default:
 280               if (ISALPHA (c))
 281                 {
 282                   *rx++ = '[';
 283                   *rx++ = TOLOWER (c);
 284                   *rx++ = TOUPPER (c);
 285                   *rx++ = ']';
 286                 }
 287               else
 288                 *rx++ = c;
 289               break;
 290             }
 291         }
 292       else
 293         {
 294           /* Replace non-syntax fields with globs.  */
 295           *rx++ = '.';
 296           *rx++ = '*';
 297         }
 298     }
 299
 300   /* Trailing whitespace ok.  */
 301   * rx++ = '[';
 302   * rx++ = ' ';
 303   * rx++ = '\t';
 304   * rx++ = ']';
 305   * rx++ = '*';
 306
 307   /* But anchor it after that.  */
 308   * rx++ = '$';
 309   * rx = '\0';
 310
 311   CGEN_INSN_RX (insn) = xmalloc (sizeof (regex_t));
 312   reg_err = regcomp ((regex_t *) CGEN_INSN_RX (insn), rxbuf, REG_NOSUB);
 313
 314   if (reg_err == 0)
 315     return NULL;
 316   else
 317     {
 318       static char msg[80];
 319
 320       regerror (reg_err, (regex_t *) CGEN_INSN_RX (insn), msg, 80);
 321       regfree ((regex_t *) CGEN_INSN_RX (insn));
 322       free (CGEN_INSN_RX (insn));
 323       (CGEN_INSN_RX (insn)) = NULL;
 324       return msg;
 325     }
 326 }
 327
 328 \f
 329 /* Default insn parser.
 330
 331    The syntax string is scanned and operands are parsed and stored in FIELDS.
 332    Relocs are queued as we go via other callbacks.
 333
 334    ??? Note that this is currently an all-or-nothing parser.  If we fail to
 335    parse the instruction, we return 0 and the caller will start over from
 336    the beginning.  Backtracking will be necessary in parsing subexpressions,
 337    but that can be handled there.  Not handling backtracking here may get
 338    expensive in the case of the m68k.  Deal with later.
 339
 340    Returns NULL for success, an error message for failure.  */
 341
 342 static const char *
 343 parse_insn_normal (CGEN_CPU_DESC cd,
 344                    const CGEN_INSN *insn,
 345                    const char **strp,
 346                    CGEN_FIELDS *fields)
 347 {
 348   /* ??? Runtime added insns not handled yet.  */
 349   const CGEN_SYNTAX *syntax = CGEN_INSN_SYNTAX (insn);
 350   const char *str = *strp;
 351   const char *errmsg;
 352   const char *p;
 353   const CGEN_SYNTAX_CHAR_TYPE * syn;
 354 #ifdef CGEN_MNEMONIC_OPERANDS
 355   /* FIXME: wip */
 356   int past_opcode_p;
 357 #endif
 358
 359   /* For now we assume the mnemonic is first (there are no leading operands).
 360      We can parse it without needing to set up operand parsing.
 361      GAS's input scrubber will ensure mnemonics are lowercase, but we may
 362      not be called from GAS.  */
 363   p = CGEN_INSN_MNEMONIC (insn);
 364   while (*p && TOLOWER (*p) == TOLOWER (*str))
 365     ++p, ++str;
 366
 367   if (* p)
 368     return _("unrecognized instruction");
 369
 370 #ifndef CGEN_MNEMONIC_OPERANDS
 371   if (* str && ! ISSPACE (* str))
 372     return _("unrecognized instruction");
 373 #endif
 374
 375   CGEN_INIT_PARSE (cd);
 376   cgen_init_parse_operand (cd);
 377 #ifdef CGEN_MNEMONIC_OPERANDS
 378   past_opcode_p = 0;
 379 #endif
 380
 381   /* We don't check for (*str != '\0') here because we want to parse
 382      any trailing fake arguments in the syntax string.  */
 383   syn = CGEN_SYNTAX_STRING (syntax);
 384
 385   /* Mnemonics come first for now, ensure valid string.  */
 386   if (! CGEN_SYNTAX_MNEMONIC_P (* syn))
 387     abort ();
 388
 389   ++syn;
 390
 391   while (* syn != 0)
 392     {
 393       /* Non operand chars must match exactly.  */
 394       if (CGEN_SYNTAX_CHAR_P (* syn))
 395         {
 396           /* FIXME: While we allow for non-GAS callers above, we assume the
 397              first char after the mnemonic part is a space.  */
 398           /* FIXME: We also take inappropriate advantage of the fact that
 399              GAS's input scrubber will remove extraneous blanks.  */
 400           if (TOLOWER (*str) == TOLOWER (CGEN_SYNTAX_CHAR (* syn)))
 401             {
 402 #ifdef CGEN_MNEMONIC_OPERANDS
 403               if (CGEN_SYNTAX_CHAR(* syn) == ' ')
 404                 past_opcode_p = 1;
 405 #endif
 406               ++ syn;
 407               ++ str;
 408             }
 409           else if (*str)
 410             {
 411               /* Syntax char didn't match.  Can't be this insn.  */
 412               static char msg [80];
 413
 414               /* xgettext:c-format */
 415               sprintf (msg, _("syntax error (expected char `%c', found `%c')"),
 416                        CGEN_SYNTAX_CHAR(*syn), *str);
 417               return msg;
 418             }
 419           else
 420             {
 421               /* Ran out of input.  */
 422               static char msg [80];
 423
 424               /* xgettext:c-format */
 425               sprintf (msg, _("syntax error (expected char `%c', found end of instruction)"),
 426                        CGEN_SYNTAX_CHAR(*syn));
 427               return msg;
 428             }
 429           continue;
 430         }
 431
 432 #ifdef CGEN_MNEMONIC_OPERANDS
 433       (void) past_opcode_p;
 434 #endif
 435       /* We have an operand of some sort.  */
 436       errmsg = cd->parse_operand (cd, CGEN_SYNTAX_FIELD (*syn), &str, fields);
 437       if (errmsg)
 438         return errmsg;
 439
 440       /* Done with this operand, continue with next one.  */
 441       ++ syn;
 442     }
 443
 444   /* If we're at the end of the syntax string, we're done.  */
 445   if (* syn == 0)
 446     {
 447       /* FIXME: For the moment we assume a valid `str' can only contain
 448          blanks now.  IE: We needn't try again with a longer version of
 449          the insn and it is assumed that longer versions of insns appear
 450          before shorter ones (eg: lsr r2,r3,1 vs lsr r2,r3).  */
 451       while (ISSPACE (* str))
 452         ++ str;
 453
 454       if (* str != '\0')
 455         return _("junk at end of line"); /* FIXME: would like to include `str' */
 456
 457       return NULL;
 458     }
 459
 460   /* We couldn't parse it.  */
 461   return _("unrecognized instruction");
 462 }
 463 \f
 464 /* Main entry point.
 465    This routine is called for each instruction to be assembled.
 466    STR points to the insn to be assembled.
 467    We assume all necessary tables have been initialized.
 468    The assembled instruction, less any fixups, is stored in BUF.
 469    Remember that if CGEN_INT_INSN_P then BUF is an int and thus the value
 470    still needs to be converted to target byte order, otherwise BUF is an array
 471    of bytes in target byte order.
 472    The result is a pointer to the insn's entry in the opcode table,
 473    or NULL if an error occured (an error message will have already been
 474    printed).
 475
 476    Note that when processing (non-alias) macro-insns,
 477    this function recurses.
 478
 479    ??? It's possible to make this cpu-independent.
 480    One would have to deal with a few minor things.
 481    At this point in time doing so would be more of a curiosity than useful
 482    [for example this file isn't _that_ big], but keeping the possibility in
 483    mind helps keep the design clean.  */
 484
 485 const CGEN_INSN *
 486 bpf_cgen_assemble_insn (CGEN_CPU_DESC cd,
 487                            const char *str,
 488                            CGEN_FIELDS *fields,
 489                            CGEN_INSN_BYTES_PTR buf,
 490                            char **errmsg)
 491 {
 492   const char *start;
 493   CGEN_INSN_LIST *ilist;
 494   const char *parse_errmsg = NULL;
 495   const char *insert_errmsg = NULL;
 496   int recognized_mnemonic = 0;
 497
 498   /* Skip leading white space.  */
 499   while (ISSPACE (* str))
 500     ++ str;
 501
 502   /* The instructions are stored in hashed lists.
 503      Get the first in the list.  */
 504   ilist = CGEN_ASM_LOOKUP_INSN (cd, str);
 505
 506   /* Keep looking until we find a match.  */
 507   start = str;
 508   for ( ; ilist != NULL ; ilist = CGEN_ASM_NEXT_INSN (ilist))
 509     {
 510       const CGEN_INSN *insn = ilist->insn;
 511       recognized_mnemonic = 1;
 512
 513 #ifdef CGEN_VALIDATE_INSN_SUPPORTED
 514       /* Not usually needed as unsupported opcodes
 515          shouldn't be in the hash lists.  */
 516       /* Is this insn supported by the selected cpu?  */
 517       if (! bpf_cgen_insn_supported (cd, insn))
 518         continue;
 519 #endif
 520       /* If the RELAXED attribute is set, this is an insn that shouldn't be
 521          chosen immediately.  Instead, it is used during assembler/linker
 522          relaxation if possible.  */
 523       if (CGEN_INSN_ATTR_VALUE (insn, CGEN_INSN_RELAXED) != 0)
 524         continue;
 525
 526       str = start;
 527
 528       /* Skip this insn if str doesn't look right lexically.  */
 529       if (CGEN_INSN_RX (insn) != NULL &&
 530           regexec ((regex_t *) CGEN_INSN_RX (insn), str, 0, NULL, 0) == REG_NOMATCH)
 531         continue;
 532
 533       /* Allow parse/insert handlers to obtain length of insn.  */
 534       CGEN_FIELDS_BITSIZE (fields) = CGEN_INSN_BITSIZE (insn);
 535
 536       parse_errmsg = CGEN_PARSE_FN (cd, insn) (cd, insn, & str, fields);
 537       if (parse_errmsg != NULL)
 538         continue;
 539
 540       /* ??? 0 is passed for `pc'.  */
 541       insert_errmsg = CGEN_INSERT_FN (cd, insn) (cd, insn, fields, buf,
 542                                                  (bfd_vma) 0);
 543       if (insert_errmsg != NULL)
 544         continue;
 545
 546       /* It is up to the caller to actually output the insn and any
 547          queued relocs.  */
 548       return insn;
 549     }
 550
 551   {
 552     static char errbuf[150];
 553     const char *tmp_errmsg;
 554 #ifdef CGEN_VERBOSE_ASSEMBLER_ERRORS
 555 #define be_verbose 1
 556 #else
 557 #define be_verbose 0
 558 #endif
 559
 560     if (be_verbose)
 561       {
 562         /* If requesting verbose error messages, use insert_errmsg.
 563            Failing that, use parse_errmsg.  */
 564         tmp_errmsg = (insert_errmsg ? insert_errmsg :
 565                       parse_errmsg ? parse_errmsg :
 566                       recognized_mnemonic ?
 567                       _("unrecognized form of instruction") :
 568                       _("unrecognized instruction"));
 569
 570         if (strlen (start) > 50)
 571           /* xgettext:c-format */
 572           sprintf (errbuf, "%s `%.50s...'", tmp_errmsg, start);
 573         else
 574           /* xgettext:c-format */
 575           sprintf (errbuf, "%s `%.50s'", tmp_errmsg, start);
 576       }
 577     else
 578       {
 579         if (strlen (start) > 50)
 580           /* xgettext:c-format */
 581           sprintf (errbuf, _("bad instruction `%.50s...'"), start);
 582         else
 583           /* xgettext:c-format */
 584           sprintf (errbuf, _("bad instruction `%.50s'"), start);
 585       }
 586
 587     *errmsg = errbuf;
 588     return NULL;
 589   }
 590 }