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/* tc-tic54x.c -- Assembly code for the Texas Instruments TMS320C54X

   Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,

   2009  Free Software Foundation, Inc.

   Contributed by Timothy Wall (twall@cygnus.com)

   This file is part of GAS, the GNU Assembler.

   GAS is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3, or (at your option)

   any later version.

   GAS is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with GAS; see the file COPYING.  If not, write to the Free

   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA

   02110-1301, USA.  */

/* Texas Instruments TMS320C54X machine specific gas.

   Written by Timothy Wall (twall@alum.mit.edu).

   Valuable things to do:

   Pipeline conflict warnings

   We encode/decode "ld #_label, dp" differently in relocatable files

     This means we're not compatible with TI output containing those

     expressions.  We store the upper nine bits; TI stores the lower nine

     bits.  How they recover the original upper nine bits is beyond me.

   Tests to add to expect testsuite:

     '=' and '==' with .if, .elseif, and .break

   Incompatibilities (mostly trivial):

   We don't allow '''

   We fill text section with zeroes instead of "nop"s

   We don't convert '' or "" to a single instance

   We don't convert '' to '\0'

   We don't allow strings with .byte/.half/.short/.long

   Probably details of the subsym stuff are different

   TI sets labels to be data type 4 (T_INT); GAS uses T_NULL.

   COFF1 limits section names to 8 characters.

   Some of the default behavior changed from COFF1 to COFF2.  */

#include <limits.h>

#include "as.h"

#include "safe-ctype.h"

#include "sb.h"

#include "macro.h"

#include "subsegs.h"

#include "struc-symbol.h"

#include "opcode/tic54x.h"

#include "obj-coff.h"

#include <math.h>

static struct stag

{

  symbolS *sym;                 /* Symbol for this stag; value is offset.  */

  const char *name;             /* Shortcut to symbol name.  */

  bfd_vma size;                 /* Size of struct/union.  */

  int current_bitfield_offset;  /* Temporary for tracking fields.  */

  int is_union;

  struct stag_field             /* List of fields.  */

  {

    const char *name;

    bfd_vma offset;             /* Of start of this field.  */

    int bitfield_offset;        /* Of start of this field.  */

    struct stag *stag;          /* If field is struct/union.  */

    struct stag_field *next;

  } *field;

  /* For nesting; used only in stag construction.  */

  struct stag *inner;           /* Enclosed .struct.  */

  struct stag *outer;           /* Enclosing .struct.  */

} *current_stag = NULL;

#define MAX_LINE 256 /* Lines longer than this are truncated by TI's asm.  */

typedef struct _tic54x_insn

{

  const insn_template *tm;      /* Opcode template.  */

  char mnemonic[MAX_LINE];      /* Opcode name/mnemonic.  */

  char parmnemonic[MAX_LINE];   /* 2nd mnemonic of parallel insn.  */

  int opcount;

  struct opstruct

  {

    char buf[MAX_LINE];

    enum optype type;

    expressionS exp;

  } operands[MAX_OPERANDS];

  int paropcount;

  struct opstruct paroperands[MAX_OPERANDS];

  int is_lkaddr;

  int lkoperand;

  int words;                    /* Size of insn in 16-bit words.  */

  int using_default_dst;        /* Do we need to explicitly set an

                                   omitted OP_DST operand?  */

  struct

  {

    unsigned short word;             /* Final encoded opcode data.  */

    int unresolved;

    int r_nchars;                    /* Relocation size.  */

    bfd_reloc_code_real_type r_type; /* Relocation type.  */

    expressionS addr_expr;           /* Storage for unresolved expressions.  */

  } opcode[3];

} tic54x_insn;

enum cpu_version

{

  VNONE = 0, V541 = 1, V542 = 2, V543 = 3, V545 = 5, V548 = 8, V549 = 9,

  V545LP = 15, V546LP = 16

};

enum address_mode

{

  c_mode,   /* 16-bit addresses.  */

  far_mode  /* >16-bit addresses.  */

};

static segT stag_saved_seg;

static subsegT stag_saved_subseg;

const char comment_chars[] = ";";

const char line_comment_chars[] = ";*#"; /* At column zero only.  */

const char line_separator_chars[] = ""; /* Not permitted.  */

int emitting_long = 0;

/* Characters which indicate that this is a floating point constant.  */

const char FLT_CHARS[] = "fF";

/* Characters that can be used to separate mantissa from exp in FP

   nums.  */

const char EXP_CHARS[] = "eE";

const char *md_shortopts = "";

#define OPTION_ADDRESS_MODE     (OPTION_MD_BASE)

#define OPTION_CPU_VERSION      (OPTION_ADDRESS_MODE + 1)

#define OPTION_COFF_VERSION     (OPTION_CPU_VERSION + 1)

#define OPTION_STDERR_TO_FILE   (OPTION_COFF_VERSION + 1)

struct option md_longopts[] =

{

  { "mfar-mode",       no_argument,         NULL, OPTION_ADDRESS_MODE },

  { "mf",              no_argument,         NULL, OPTION_ADDRESS_MODE },

  { "mcpu",            required_argument,   NULL, OPTION_CPU_VERSION },

  { "merrors-to-file", required_argument,   NULL, OPTION_STDERR_TO_FILE },

  { "me",              required_argument,   NULL, OPTION_STDERR_TO_FILE },

  { NULL,              no_argument,         NULL, 0},

};

size_t md_longopts_size = sizeof (md_longopts);

static int assembly_begun = 0;

/* Addressing mode is not entirely implemented; the latest rev of the Other

   assembler doesn't seem to make any distinction whatsoever; all relocations

   are stored as extended relocatiosn.  Older versions used REL16 vs RELEXT16,

   but now it seems all relocations are RELEXT16.  We use all RELEXT16.

   The cpu version is kind of a waste of time as well.  There is one

   instruction (RND) for LP devices only, and several for devices with

   extended addressing only.  We include it for compatibility.  */

static enum address_mode amode = c_mode;

static enum cpu_version cpu = VNONE;

/* Include string substitutions in listing?  */

static int listing_sslist = 0;

/* Did we do subsym substitutions on the line?  */

static int substitution_line = 0;

/* Last label seen.  */

static symbolS *last_label_seen = NULL;

/* This ensures that all new labels are unique.  */

static int local_label_id;

static struct hash_control *subsym_recurse_hash; /* Prevent infinite recurse.  */

static struct hash_control *math_hash; /* Built-in math functions.  */

/* Allow maximum levels of macro nesting; level 0 is the main substitution

   symbol table.  The other assembler only does 32 levels, so there!  */

static struct hash_control *subsym_hash[100];

/* Keep track of local labels so we can substitute them before GAS sees them

   since macros use their own 'namespace' for local labels, use a separate hash

   We do our own local label handling 'cuz it's subtly different from the

   stock GAS handling.

   We use our own macro nesting counter, since GAS overloads it when expanding

   other things (like conditionals and repeat loops).  */

static int macro_level = 0;

static struct hash_control *local_label_hash[100];

/* Keep track of struct/union tags.  */

static struct hash_control *stag_hash;

static struct hash_control *op_hash;

static struct hash_control *parop_hash;

static struct hash_control *reg_hash;

static struct hash_control *mmreg_hash;

static struct hash_control *cc_hash;

static struct hash_control *cc2_hash;

static struct hash_control *cc3_hash;

static struct hash_control *sbit_hash;

static struct hash_control *misc_symbol_hash;

/* Only word (et al.), align, or conditionals are allowed within

   .struct/.union.  */

#define ILLEGAL_WITHIN_STRUCT()                                 \

  do                                                            \

    if (current_stag != NULL)                                   \

      {                                                         \

        as_bad (_("pseudo-op illegal within .struct/.union"));  \

        return;                                                 \

      }                                                         \

  while (0)

static void subsym_create_or_replace (char *, char *);

static char *subsym_lookup (char *, int);

static char *subsym_substitute (char *, int);

void

md_show_usage (FILE *stream)

{

  fprintf (stream, _("C54x-specific command line  options:\n"));

  fprintf (stream, _("-mfar-mode | -mf          Use extended addressing\n"));

  fprintf (stream, _("-mcpu=<CPU version>       Specify the CPU version\n"));

  fprintf (stream, _("-merrors-to-file <filename>\n"));

  fprintf (stream, _("-me <filename>            Redirect errors to a file\n"));

}

/* Output a single character (upper octect is zero).  */

static void

tic54x_emit_char (char c)

{

  expressionS exp;

  exp.X_op = O_constant;

  exp.X_add_number = c;

  emit_expr (&exp, 2);

}

/* Walk backwards in the frag chain.  */

static fragS *

frag_prev (fragS *frag, segT seg)

{

  segment_info_type *seginfo = seg_info (seg);

  fragS *fragp;

  for (fragp = seginfo->frchainP->frch_root; fragp; fragp = fragp->fr_next)

    if (fragp->fr_next == frag)

      return fragp;

  return NULL;

}

static fragS *

bit_offset_frag (fragS *frag, segT seg)

{

  while (frag != NULL)

    {

      if (frag->fr_fix == 0

          && frag->fr_opcode == NULL

          && frag->tc_frag_data == 0)

        frag = frag_prev (frag, seg);

      else

        return frag;

    }

  return NULL;

}

/* Return the number of bits allocated in the most recent word, or zero if

   none. .field/.space/.bes may leave words partially allocated.  */

static int

frag_bit_offset (fragS *frag, segT seg)

{

  frag = bit_offset_frag (frag, seg);

  if (frag)

    return frag->fr_opcode != NULL ? -1 : frag->tc_frag_data;

  return 0;

}

/* Read an expression from a C string; returns a pointer past the end of the

   expression.  */

static char *

parse_expression (char *str, expressionS *exp)

{

  char *s;

  char *tmp;

  tmp = input_line_pointer;     /* Save line pointer.  */

  input_line_pointer = str;

  expression (exp);

  s = input_line_pointer;

  input_line_pointer = tmp;     /* Restore line pointer.  */

  return s;                     /* Return pointer to where parsing stopped.  */

}

/* .asg "character-string"|character-string, symbol

   .eval is the only pseudo-op allowed to perform arithmetic on substitution

   symbols.  all other use of symbols defined with .asg are currently

   unsupported.  */

static void

tic54x_asg (int x ATTRIBUTE_UNUSED)

{

  int c;

  char *name;

  char *str;

  char *tmp;

  int quoted = *input_line_pointer == '"';

  ILLEGAL_WITHIN_STRUCT ();

  if (quoted)

    {

      int len;

      str = demand_copy_C_string (&len);

      c = *input_line_pointer;

    }

  else

    {

      str = input_line_pointer;

      while ((c = *input_line_pointer) != ',')

        {

          if (is_end_of_line[(int) *input_line_pointer])

            break;

          ++input_line_pointer;

        }

      *input_line_pointer = 0;

    }

  if (c != ',')

    {

      as_bad (_("Comma and symbol expected for '.asg STRING, SYMBOL'"));

      ignore_rest_of_line ();

      return;

    }

  name = ++input_line_pointer;

  c = get_symbol_end ();        /* Get terminator.  */

  if (!ISALPHA (*name))

    {

      as_bad (_("symbols assigned with .asg must begin with a letter"));

      ignore_rest_of_line ();

      return;

    }

  tmp = xmalloc (strlen (str) + 1);

  strcpy (tmp, str);

  str = tmp;

  tmp = xmalloc (strlen (name) + 1);

  strcpy (tmp, name);

  name = tmp;

  subsym_create_or_replace (name, str);

  *input_line_pointer = c;

  demand_empty_rest_of_line ();

}

/* .eval expression, symbol

   There's something screwy about this.  The other assembler sometimes does and

   sometimes doesn't substitute symbols defined with .eval.

   We'll put the symbols into the subsym table as well as the normal symbol

   table, since that's what works best.  */

static void

tic54x_eval (int x ATTRIBUTE_UNUSED)

{

  char c;

  int value;

  char *name;

  symbolS *symbolP;

  char valuestr[32], *tmp;

  int quoted;

  ILLEGAL_WITHIN_STRUCT ();

  SKIP_WHITESPACE ();

  quoted = *input_line_pointer == '"';

  if (quoted)

    ++input_line_pointer;

  value = get_absolute_expression ();

  if (quoted)

    {

      if (*input_line_pointer != '"')

        {

          as_bad (_("Unterminated string after absolute expression"));

          ignore_rest_of_line ();

          return;

        }

      ++input_line_pointer;

    }

  if (*input_line_pointer++ != ',')

    {

      as_bad (_("Comma and symbol expected for '.eval EXPR, SYMBOL'"));

      ignore_rest_of_line ();

      return;

    }

  name = input_line_pointer;

  c = get_symbol_end ();        /* Get terminator.  */

  tmp = xmalloc (strlen (name) + 1);

  name = strcpy (tmp, name);

  *input_line_pointer = c;

  if (!ISALPHA (*name))

    {

      as_bad (_("symbols assigned with .eval must begin with a letter"));

      ignore_rest_of_line ();

      return;

    }

  symbolP = symbol_new (name, absolute_section,

                        (valueT) value, &zero_address_frag);

  SF_SET_LOCAL (symbolP);

  symbol_table_insert (symbolP);

  /* The "other" assembler sometimes doesn't put .eval's in the subsym table

     But since there's not written rule as to when, don't even bother trying

     to match their behavior.  */

  sprintf (valuestr, "%d", value);

  tmp = xmalloc (strlen (valuestr) + 1);

  strcpy (tmp, valuestr);

  subsym_create_or_replace (name, tmp);

  demand_empty_rest_of_line ();

}

/* .bss symbol, size [, [blocking flag] [, alignment flag]

   alignment is to a longword boundary; blocking is to 128-word boundary.

   1) if there is a hole in memory, this directive should attempt to fill it

      (not yet implemented).

   2) if the blocking flag is not set, allocate at the current SPC

      otherwise, check to see if the current SPC plus the space to be

      allocated crosses the page boundary (128 words).

      if there's not enough space, create a hole and align with the next page

      boundary.

      (not yet implemented).  */

static void

tic54x_bss (int x ATTRIBUTE_UNUSED)

{

  char c;

  char *name;

  char *p;

  int words;

  segT current_seg;

  subsegT current_subseg;

  symbolS *symbolP;

  int block = 0;

  int align = 0;

  ILLEGAL_WITHIN_STRUCT ();

  current_seg = now_seg;        /* Save current seg.  */

  current_subseg = now_subseg;  /* Save current subseg.  */

  name = input_line_pointer;

  c = get_symbol_end ();        /* Get terminator.  */

  if (c != ',')

    {

      as_bad (_(".bss size argument missing\n"));

      ignore_rest_of_line ();

      return;

    }

  ++input_line_pointer;

  words = get_absolute_expression ();

  if (words < 0)

    {

      as_bad (_(".bss size %d < 0!"), words);

      ignore_rest_of_line ();

      return;

    }

  if (*input_line_pointer == ',')

    {

      /* The blocking flag may be missing.  */

      ++input_line_pointer;

      if (*input_line_pointer != ',')

        block = get_absolute_expression ();

      else

        block = 0;

      if (*input_line_pointer == ',')

        {

          ++input_line_pointer;

          align = get_absolute_expression ();

        }

      else

        align = 0;

    }

  else

    block = align = 0;

  subseg_set (bss_section, 0);

  symbolP = symbol_find_or_make (name);

  if (S_GET_SEGMENT (symbolP) == bss_section)

    symbolP->sy_frag->fr_symbol = (symbolS *) NULL;

  symbol_set_frag (symbolP, frag_now);

  p = frag_var (rs_org, 1, 1, (relax_substateT) 0, symbolP,

                (offsetT) (words * OCTETS_PER_BYTE), (char *) 0);

  *p = 0;                        /* Fill char.  */

  S_SET_SEGMENT (symbolP, bss_section);

  /* The symbol may already have been created with a preceding

     ".globl" directive -- be careful not to step on storage class

     in that case.  Otherwise, set it to static.  */

  if (S_GET_STORAGE_CLASS (symbolP) != C_EXT)

    S_SET_STORAGE_CLASS (symbolP, C_STAT);

  if (align)

    {

      /* s_align eats end of line; restore it */

      s_align_bytes (4);

      --input_line_pointer;

    }

  if (block)

    bss_section->flags |= SEC_TIC54X_BLOCK;

  subseg_set (current_seg, current_subseg);     /* Restore current seg.  */

  demand_empty_rest_of_line ();

}

static void

stag_add_field_symbols (struct stag *stag,

                        const char *path,

                        bfd_vma base_offset,

                        symbolS *rootsym,

                        const char *root_stag_name)

{

  char prefix[strlen (path) + 2];

  struct stag_field *field = stag->field;

  /* Construct a symbol for every field contained within this structure

     including fields within structure fields.  */

  strcpy (prefix, path);

  if (*path)

    strcat (prefix, ".");

  while (field != NULL)

    {

      int len = strlen (prefix) + strlen (field->name) + 2;

      char *name = xmalloc (len);

      strcpy (name, prefix);

      strcat (name, field->name);

      if (rootsym == NULL)

        {

          symbolS *sym;

          sym = symbol_new (name, absolute_section,

                            (field->stag ? field->offset :

                             (valueT) (base_offset + field->offset)),

                            &zero_address_frag);

          SF_SET_LOCAL (sym);

          symbol_table_insert (sym);

        }

      else

        {

          char *replacement = xmalloc (strlen (name)

                                       + strlen (stag->name) + 2);

          strcpy (replacement, S_GET_NAME (rootsym));

          strcat (replacement, "+");

          strcat (replacement, root_stag_name);

          strcat (replacement, name + strlen (S_GET_NAME (rootsym)));

          hash_insert (subsym_hash[0], name, replacement);

        }

      /* Recurse if the field is a structure.

         Note the field offset is relative to the outermost struct.  */

      if (field->stag != NULL)

        stag_add_field_symbols (field->stag, name,

                                field->offset,

                                rootsym, root_stag_name);

      field = field->next;

    }

}

/* Keep track of stag fields so that when structures are nested we can add the

   complete dereferencing symbols to the symbol table.  */

static void

stag_add_field (struct stag *parent,

                const char *name,

                bfd_vma offset,

                struct stag *stag)

{

  struct stag_field *sfield = xmalloc (sizeof (struct stag_field));

  memset (sfield, 0, sizeof (*sfield));

  sfield->name = strcpy (xmalloc (strlen (name) + 1), name);

  sfield->offset = offset;

  sfield->bitfield_offset = parent->current_bitfield_offset;

  sfield->stag = stag;

  if (parent->field == NULL)

    parent->field = sfield;

  else

    {

      struct stag_field *sf = parent->field;

      while (sf->next != NULL)

        sf = sf->next;

      sf->next = sfield;

    }

  /* Only create a symbol for this field if the parent has no name.  */

  if (!strncmp (".fake", parent->name, 5))

    {

      symbolS *sym = symbol_new (name, absolute_section,

                                 (valueT) offset, &zero_address_frag);

      SF_SET_LOCAL (sym);

      symbol_table_insert (sym);

    }

}

/* [STAG] .struct       [OFFSET]

   Start defining structure offsets (symbols in absolute section).  */

static void

tic54x_struct (int arg)

{

  int start_offset = 0;

  int is_union = arg;

  if (!current_stag)

    {

      /* Starting a new struct, switch to absolute section.  */

      stag_saved_seg = now_seg;

      stag_saved_subseg = now_subseg;

      subseg_set (absolute_section, 0);

    }

  /* Align the current pointer.  */

  else if (current_stag->current_bitfield_offset != 0)

    {

      ++abs_section_offset;

      current_stag->current_bitfield_offset = 0;

    }

  /* Offset expression is only meaningful for global .structs.  */

  if (!is_union)

    {

      /* Offset is ignored in inner structs.  */

      SKIP_WHITESPACE ();

      if (!is_end_of_line[(int) *input_line_pointer])

        start_offset = get_absolute_expression ();

      else

        start_offset = 0;

    }

  if (current_stag)

    {

      /* Nesting, link to outer one.  */

      current_stag->inner = (struct stag *) xmalloc (sizeof (struct stag));

      memset (current_stag->inner, 0, sizeof (struct stag));

      current_stag->inner->outer = current_stag;

      current_stag = current_stag->inner;

      if (start_offset)

        as_warn (_("Offset on nested structures is ignored"));

      start_offset = abs_section_offset;

    }

  else

    {

      current_stag = (struct stag *) xmalloc (sizeof (struct stag));

      memset (current_stag, 0, sizeof (struct stag));

      abs_section_offset = start_offset;

    }

  current_stag->is_union = is_union;

  if (line_label == NULL)

    {

      static int struct_count = 0;

      char fake[] = ".fake_stagNNNNNNN";

      sprintf (fake, ".fake_stag%d", struct_count++);

      current_stag->sym = symbol_new (fake, absolute_section,

                                      (valueT) abs_section_offset,