bison/src/output.c

/* Output the generated parsing program for bison,
   Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002
   Free Software Foundation, Inc.

   This file is part of Bison, the GNU Compiler Compiler.

   Bison 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 2, or (at your option)
   any later version.

   Bison 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 Bison; see the file COPYING.  If not, write to the Free
   Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.  */


/* The parser tables consist of these tables.

   YYTRANSLATE = vector mapping yylex's token numbers into bison's
   token numbers.

   YYTNAME = vector of string-names indexed by bison token number.

   YYTOKNUM = vector of yylex token numbers corresponding to entries
   in YYTNAME.

   YYRLINE = vector of line-numbers of all rules.  For yydebug
   printouts.

   YYRHS = vector of items of all rules.  This is exactly what RITEMS
   contains.  For yydebug and for semantic parser.

   YYPRHS[R] = index in YYRHS of first item for rule R.

   YYR1[R] = symbol number of symbol that rule R derives.

   YYR2[R] = number of symbols composing right hand side of rule R.

   YYSTOS[S] = the symbol number of the symbol that leads to state S.

   YYDEFACT[S] = default rule to reduce with in state s, when YYTABLE
   doesn't specify something else to do.  Zero means the default is an
   error.

   YYDEFGOTO[I] = default state to go to after a reduction of a rule
   that generates variable NTOKENS + I, except when YYTABLE specifies
   something else to do.

   YYPACT[S] = index in YYTABLE of the portion describing state S.
   The lookahead token's type is used to index that portion to find
   out what to do.

   If the value in YYTABLE is positive, we shift the token and go to
   that state.

   If the value is negative, it is minus a rule number to reduce by.

   If the value is zero, the default action from YYDEFACT[S] is used.

   YYPGOTO[I] = the index in YYTABLE of the portion describing what to
   do after reducing a rule that derives variable I + NTOKENS.  This
   portion is indexed by the parser state number, S, as of before the
   text for this nonterminal was read.  The value from YYTABLE is the
   state to go to if the corresponding value in YYCHECK is S.

   YYTABLE = a vector filled with portions for different uses, found
   via YYPACT and YYPGOTO.

   YYCHECK = a vector indexed in parallel with YYTABLE.  It indicates,
   in a roundabout way, the bounds of the portion you are trying to
   examine.

   Suppose that the portion of YYTABLE starts at index P and the index
   to be examined within the portion is I.  Then if YYCHECK[P+I] != I,
   I is outside the bounds of what is actually allocated, and the
   default (from YYDEFACT or YYDEFGOTO) should be used.  Otherwise,
   YYTABLE[P+I] should be used.

   YYFINAL = the state number of the termination state.  YYFLAG = most
   negative short int.  Used to flag ??  */

#include "system.h"
#include "quotearg.h"
#include "error.h"
#include "getargs.h"
#include "files.h"
#include "gram.h"
#include "complain.h"
#include "output.h"
#include "reader.h"
#include "symtab.h"
#include "tables.h"
#include "muscle_tab.h"

/* From src/scan-skel.l. */
void m4_invoke PARAMS ((const char *definitions));


static struct obstack format_obstack;

int error_verbose = 0;



/*-------------------------------------------------------------------.
| Create a function NAME which associates to the muscle NAME the     |
| result of formatting the FIRST and then TABLE_DATA[BEGIN..END[ (of |
| TYPE), and to the muscle NAME_max, the max value of the            |
| TABLE_DATA.                                                        |
`-------------------------------------------------------------------*/


#define GENERATE_MUSCLE_INSERT_TABLE(Name, Type)			\
									\
static void								\
Name (const char *name,							\
      Type *table_data,							\
      Type first,							\
      int begin,							\
      int end)								\
{									\
  Type min = first;							\
  Type max = first;							\
  int i;								\
  int j = 1;								\
									\
  obstack_fgrow1 (&format_obstack, "%6d", first);			\
  for (i = begin; i < end; ++i)						\
    {									\
      obstack_1grow (&format_obstack, ',');				\
      if (j >= 10)							\
	{								\
	  obstack_sgrow (&format_obstack, "\n  ");			\
	  j = 1;							\
	}								\
      else								\
	++j;								\
      obstack_fgrow1 (&format_obstack, "%6d", table_data[i]);		\
      if (table_data[i] < min)						\
	min = table_data[i];						\
      if (max < table_data[i])						\
	max = table_data[i];						\
    }									\
  obstack_1grow (&format_obstack, 0);					\
  muscle_insert (name, obstack_finish (&format_obstack));		\
									\
  /* Build `NAME_min' and `NAME_max' in the obstack. */			\
  obstack_fgrow1 (&format_obstack, "%s_min", name);			\
  obstack_1grow (&format_obstack, 0);					\
  MUSCLE_INSERT_LONG_INT (obstack_finish (&format_obstack),		\
			  (long int) min);				\
  obstack_fgrow1 (&format_obstack, "%s_max", name);			\
  obstack_1grow (&format_obstack, 0);					\
  MUSCLE_INSERT_LONG_INT (obstack_finish (&format_obstack),		\
			  (long int) max);				\
}

GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_unsigned_int_table, unsigned int)
GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_int_table, int)
GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_short_table, short)
GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_base_table, base_t)
GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_rule_number_table, rule_number_t)
GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_symbol_number_table, symbol_number_t)
GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_item_number_table, item_number_t)
GENERATE_MUSCLE_INSERT_TABLE(muscle_insert_state_number_table, state_number_t)


/*-----------------------------------------------------------------.
| Prepare the muscles related to the tokens: translate, tname, and |
| toknum.                                                          |
`-----------------------------------------------------------------*/

static void
prepare_tokens (void)
{
  muscle_insert_symbol_number_table ("translate",
				     token_translations,
				     token_translations[0],
				     1, max_user_token_number + 1);

  {
    int i;
    int j = 0;
    for (i = 0; i < nsyms; i++)
      {
	/* Be sure not to use twice the same QUOTEARG slot:
	   SYMBOL_TAG_GET uses slot 0.  */
	const char *cp =
	  quotearg_n_style (1, c_quoting_style,
			    symbols[i]->tag);
	/* Width of the next token, including the two quotes, the coma
	   and the space.  */
	int strsize = strlen (cp) + 2;

	if (j + strsize > 75)
	  {
	    obstack_sgrow (&format_obstack, "\n  ");
	    j = 2;
	  }

	obstack_sgrow (&format_obstack, cp);
	obstack_sgrow (&format_obstack, ", ");
	j += strsize;
      }
    /* Add a NULL entry to list of tokens (well, 0, as NULL might not be
       defined).  */
    obstack_sgrow (&format_obstack, "0");

    /* Finish table and store. */
    obstack_1grow (&format_obstack, 0);
    muscle_insert ("tname", obstack_finish (&format_obstack));
  }

  /* Output YYTOKNUM. */
  {
    int i;
    int *values = XCALLOC (int, ntokens);
    for (i = 0; i < ntokens; ++i)
      values[i] = symbols[i]->user_token_number;
    muscle_insert_int_table ("toknum", values,
			     values[0], 1, ntokens);
    free (values);
  }
}


/*-------------------------------------------------------------.
| Prepare the muscles related to the rules: rhs, prhs, r1, r2, |
| rline, dprec, merger                                         |
`-------------------------------------------------------------*/

static void
prepare_rules (void)
{
  rule_number_t r;
  unsigned int i = 0;
  item_number_t *rhs = XMALLOC (item_number_t, nritems);
  unsigned int *prhs = XMALLOC (unsigned int, nrules);
  unsigned int *rline = XMALLOC (unsigned int, nrules);
  symbol_number_t *r1 = XMALLOC (symbol_number_t, nrules);
  unsigned int *r2 = XMALLOC (unsigned int, nrules);
  short *dprec = XMALLOC (short, nrules);
  short *merger = XMALLOC (short, nrules);

  for (r = 0; r < nrules; ++r)
    {
      item_number_t *rhsp = NULL;
      /* Index of rule R in RHS. */
      prhs[r] = i;
      /* RHS of the rule R. */
      for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
	rhs[i++] = *rhsp;
      /* LHS of the rule R. */
      r1[r] = rules[r].lhs->number;
      /* Length of rule R's RHS. */
      r2[r] = i - prhs[r];
      /* Separator in RHS. */
      rhs[i++] = -1;
      /* Line where rule was defined. */
      rline[r] = rules[r].location.first_line;
      /* Dynamic precedence (GLR) */
      dprec[r] = rules[r].dprec;
      /* Merger-function index (GLR) */
      merger[r] = rules[r].merger;
    }
  assert (i == nritems);

  muscle_insert_item_number_table ("rhs", rhs, ritem[0], 1, nritems);
  muscle_insert_unsigned_int_table ("prhs", prhs, 0, 0, nrules);
  muscle_insert_unsigned_int_table ("rline", rline, 0, 0, nrules);
  muscle_insert_symbol_number_table ("r1", r1, 0, 0, nrules);
  muscle_insert_unsigned_int_table ("r2", r2, 0, 0, nrules);
  muscle_insert_short_table ("dprec", dprec, 0, 0, nrules);
  muscle_insert_short_table ("merger", merger, 0, 0, nrules);

  free (rhs);
  free (prhs);
  free (rline);
  free (r1);
  free (r2);
  free (dprec);
  free (merger);
}

/*--------------------------------------------.
| Prepare the muscles related to the states.  |
`--------------------------------------------*/

static void
prepare_states (void)
{
  state_number_t i;
  symbol_number_t *values =
    (symbol_number_t *) alloca (sizeof (symbol_number_t) * nstates);
  for (i = 0; i < nstates; ++i)
    values[i] = states[i]->accessing_symbol;
  muscle_insert_symbol_number_table ("stos", values,
				     0, 1, nstates);
}



/*----------------------------------.
| Output the user actions to OOUT.  |
`----------------------------------*/

static void
user_actions_output (FILE *out)
{
  rule_number_t r;

  fputs ("m4_define([b4_actions], \n[[", out);
  for (r = 0; r < nrules; ++r)
    if (rules[r].action)
      {
	fprintf (out, "  case %d:\n", r + 1);

	if (!no_lines_flag)
	  fprintf (out, muscle_find ("linef"),
		   rules[r].action_location.first_line,
		   quotearg_style (c_quoting_style,
				   muscle_find ("filename")));
	fprintf (out, "    %s\n    break;\n\n",
		 rules[r].action);
      }
  fputs ("]])\n\n", out);
}

/*--------------------------------------.
| Output the merge functions to OUT.   |
`--------------------------------------*/

static void
merger_output (FILE *out)
{
  int n;
  merger_list* p;

  fputs ("m4_define([b4_mergers], \n[[", out);
  for (n = 1, p = merge_functions; p != NULL; n += 1, p = p->next)
    {
      if (p->type[0] == '\0')
	fprintf (out, "  case %d: yyval = %s (*yy0, *yy1); break;\n",
		 n, p->name);
      else
	fprintf (out, "  case %d: yyval.%s = %s (*yy0, *yy1); break;\n",
		 n, p->type, p->name);
    }
  fputs ("]])\n\n", out);
}

/*---------------------------------------.
| Output the tokens definition to OOUT.  |
`---------------------------------------*/

static void
token_definitions_output (FILE *out)
{
  int i;
  int first = 1;

  fputs ("m4_define([b4_tokens], \n[", out);
  for (i = 0; i < ntokens; ++i)
    {
      symbol_t *symbol = symbols[i];
      int number = symbol->user_token_number;

      /* At this stage, if there are literal aliases, they are part of
	 SYMBOLS, so we should not find symbols which are the aliases
	 here.  */
      assert (number != USER_NUMBER_ALIAS);

      /* Skip error token.  */
      if (symbol == errtoken)
	continue;

      /* If this string has an alias, then it is necessarily the alias
	 which is to be output.  */
      if (symbol->alias)
	symbol = symbol->alias;

      /* Don't output literal chars or strings (when defined only as a
	 string).  Note that must be done after the alias resolution:
	 think about `%token 'f' "f"'.  */
      if (symbol->tag[0] == '\'' || symbol->tag[0] == '\"')
	continue;

      /* Don't #define nonliteral tokens whose names contain periods
	 or '$' (as does the default value of the EOF token).  */
      if (strchr (symbol->tag, '.') || strchr (symbol->tag, '$'))
	continue;

      fprintf (out, "%s[[[%s]], [%d]]",
	       first ? "" : ",\n", symbol->tag, number);

      first = 0;
    }
  fputs ("])\n\n", out);
}


/*----------------------------------------.
| Output the symbol destructors to OOUT.  |
`----------------------------------------*/

static void
symbol_destructors_output (FILE *out)
{
  int i;
  int first = 1;

  fputs ("m4_define([b4_symbol_destructors], \n[", out);
  for (i = 0; i < nsyms; ++i)
    if (symbols[i]->destructor)
      {
	symbol_t *symbol = symbols[i];

	/* Filename, lineno,
	   Symbol-name, Symbol-number,
	   destructor, typename. */
	fprintf (out, "%s[[[%s]], [[%d]], [[%s]], [[%d]], [[%s]], [[%s]]]",
		 first ? "" : ",\n",
		 infile, symbol->destructor_location.first_line,
		 symbol->tag,
		 symbol->number,
		 symbol->destructor,
		 symbol->type_name);

	first = 0;
      }
  fputs ("])\n\n", out);
}


/*-------------------------------------.
| Output the symbol printers to OOUT.  |
`-------------------------------------*/

static void
symbol_printers_output (FILE *out)
{
  int i;
  int first = 1;

  fputs ("m4_define([b4_symbol_printers], \n[", out);
  for (i = 0; i < nsyms; ++i)
    if (symbols[i]->destructor)
      {
	symbol_t *symbol = symbols[i];

	/* Filename, lineno,
	   Symbol-name, Symbol-number,
	   destructor, typename. */
	fprintf (out, "%s[[[%s]], [[%d]], [[%s]], [[%d]], [[%s]], [[%s]]]",
		 first ? "" : ",\n",
		 infile, symbol->printer_location.first_line,
		 symbol->tag,
		 symbol->number,
		 symbol->printer,
		 symbol->type_name);

	first = 0;
      }
  fputs ("])\n\n", out);
}


static void
prepare_actions (void)
{
  /* Figure out the actions for the specified state, indexed by
     lookahead token type.  */

  muscle_insert_rule_number_table ("defact", yydefact,
				   yydefact[0], 1, nstates);

  /* Figure out what to do after reducing with each rule, depending on
     the saved state from before the beginning of parsing the data
     that matched this rule.  */
  muscle_insert_state_number_table ("defgoto", yydefgoto,
				    yydefgoto[0], 1, nsyms - ntokens);


  /* Output PACT. */
  muscle_insert_base_table ("pact", base,
			     base[0], 1, nstates);
  MUSCLE_INSERT_INT ("pact_ninf", base_ninf);

  /* Output PGOTO. */
  muscle_insert_base_table ("pgoto", base,
			     base[nstates], nstates + 1, nvectors);

  muscle_insert_base_table ("table", table,
			    table[0], 1, high + 1);
  MUSCLE_INSERT_INT ("table_ninf", table_ninf);

  muscle_insert_base_table ("check", check,
			    check[0], 1, high + 1);

  if (glr_parser)
    {
      /* GLR parsing slightly modifies yytable and yycheck
	 (and thus yypact) so that in states with unresolved conflicts,
	 the default reduction is not used in the conflicted entries, so
	 that there is a place to put a conflict pointer.  This means that
	 yyconflp and yyconfl are nonsense for a non-GLR parser, so we
	 avoid accidents by not writing them out in that case. */
      muscle_insert_unsigned_int_table ("conflict_list_heads", conflict_table,
					conflict_table[0], 1, high+1);
      muscle_insert_unsigned_int_table ("conflicting_rules", conflict_list,
			     conflict_list[0], 1, conflict_list_cnt);
    }
}


/*---------------------------.
| Call the skeleton parser.  |
`---------------------------*/

static void
output_skeleton (void)
{
  /* Store the definition of all the muscles. */
  const char *tempdir = getenv ("TMPDIR");
  char *tempfile = NULL;
  FILE *out = NULL;
  int fd;

  if (tempdir == NULL)
    tempdir = DEFAULT_TMPDIR;
  tempfile = xmalloc (strlen (tempdir) + 11);
  sprintf (tempfile, "%s/bsnXXXXXX", tempdir);
  fd = mkstemp (tempfile);
  if (fd == -1)
    error (EXIT_FAILURE, errno, "%s", tempfile);

  out = fdopen (fd, "w");
  if (out == NULL)
    error (EXIT_FAILURE, errno, "%s", tempfile);

  /* There are no comments, especially not `#': we do want M4 expansion
     after `#': think of CPP macros!  */
  fputs ("m4_changecom()\n", out);
  fputs ("m4_init()\n", out);

  user_actions_output (out);
  merger_output (out);
  token_definitions_output (out);
  symbol_destructors_output (out);
  symbol_printers_output (out);

  muscles_m4_output (out);

  fputs ("m4_wrap([m4_divert_pop(0)])\n", out);
  fputs ("m4_divert_push(0)dnl\n", out);
  xfclose (out);

  timevar_push (TV_M4);
  m4_invoke (tempfile);
  timevar_pop (TV_M4);

  /* If `debugging', keep this file alive. */
  if (!(trace_flag & trace_tools))
    unlink (tempfile);

  free (tempfile);
}

static void
prepare (void)
{
  /* Flags. */
  MUSCLE_INSERT_INT ("locations_flag", locations_flag);
  MUSCLE_INSERT_INT ("defines_flag", defines_flag);
  MUSCLE_INSERT_INT ("error_verbose", error_verbose);
  MUSCLE_INSERT_INT ("pure", pure_parser);
  MUSCLE_INSERT_INT ("debug", debug_flag);

  /* FIXME: This is wrong: the muscles should decide whether they hold
     a copy or not, but the situation is too obscure currently.  */
  MUSCLE_INSERT_STRING ("prefix", spec_name_prefix ? spec_name_prefix : "yy");
  MUSCLE_INSERT_STRING ("output_infix", output_infix ? output_infix : "");
  MUSCLE_INSERT_STRING ("output_prefix", short_base_name);
  MUSCLE_INSERT_STRING ("output_parser_name", parser_file_name);
  MUSCLE_INSERT_STRING ("output_header_name", spec_defines_file);

  /* Symbols. */
  MUSCLE_INSERT_INT ("tokens_number", ntokens);
  MUSCLE_INSERT_INT ("nterms_number", nvars);
  MUSCLE_INSERT_INT ("undef_token_number", undeftoken->number);
  MUSCLE_INSERT_INT ("user_token_number_max", max_user_token_number);

  /* Rules. */
  MUSCLE_INSERT_INT ("rules_number", nrules);

  /* States. */
  MUSCLE_INSERT_INT ("last", high);
  MUSCLE_INSERT_INT ("final_state_number", final_state->number);
  MUSCLE_INSERT_INT ("states_number", nstates);

  /* User Code.  */
  obstack_1grow (&pre_prologue_obstack, 0);
  obstack_1grow (&post_prologue_obstack, 0);
  muscle_insert ("pre_prologue", obstack_finish (&pre_prologue_obstack));
  muscle_insert ("post_prologue", obstack_finish (&post_prologue_obstack));

  /* Find the right skeleton file.  */
  if (!skeleton)
    {
      if (glr_parser)
	skeleton = "glr.c";
      else
	skeleton = "yacc.c";
    }

  /* Parse the skeleton file and output the needed parsers.  */
  muscle_insert ("skeleton", skeleton);
}


/*----------------------------------------------------------.
| Output the parsing tables and the parser code to ftable.  |
`----------------------------------------------------------*/

void
output (void)
{
  obstack_init (&format_obstack);

  prepare_tokens ();
  prepare_rules ();
  prepare_states ();
  prepare_actions ();

  prepare ();

  /* Process the selected skeleton file.  */
  output_skeleton ();

  obstack_free (&format_obstack, NULL);
  obstack_free (&pre_prologue_obstack, NULL);
  obstack_free (&post_prologue_obstack, NULL);
}