/*
 * From: @(#)rpc_scan.c 1.11 89/02/22
 *
 * Copyright (c) 2010, Oracle America, Inc.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *     * Neither the name of the "Oracle America, Inc." nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * rpc_scan.c, Scanner for the RPC protocol compiler
 * Copyright (C) 1987, Sun Microsystems, Inc.
 */
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <libintl.h>
#include "rpc_scan.h"
#include "rpc_parse.h"
#include "rpc_util.h"
#include "proto.h"

#ifndef _
#define _(String) gettext (String)
#endif

#define startcomment(where) (where[0] == '/' && where[1] == '*')
#define endcomment(where) (where[-1] == '*' && where[0] == '/')

static int pushed = 0;		/* is a token pushed */
static token lasttok;		/* last token, if pushed */

static void unget_token (token * tokp);
static void findstrconst (const char **str, const char **val);
static void findchrconst (const char **str, const char **val);
static void findconst (const char **str, const char **val);
static void findkind (const char **mark, token * tokp);
static int cppline (const char *line);
static int directive (const char *line);
static void printdirective (const char *line);
static void docppline (const char *line, int *lineno, const char **fname);

/*
 * scan expecting 1 given token
 */
void
scan (tok_kind expect, token * tokp)
{
  get_token (tokp);
  if (tokp->kind != expect)
    expected1 (expect);
}

/*
 * scan expecting any of the 2 given tokens
 */
void
scan2 (tok_kind expect1, tok_kind expect2, token * tokp)
{
  get_token (tokp);
  if (tokp->kind != expect1 && tokp->kind != expect2)
    {
      expected2 (expect1, expect2);
    }
}

/*
 * scan expecting any of the 3 given token
 */
void
scan3 (tok_kind expect1, tok_kind expect2, tok_kind expect3, token * tokp)
{
  get_token (tokp);
  if (tokp->kind != expect1 && tokp->kind != expect2
      && tokp->kind != expect3)
    {
      expected3 (expect1, expect2, expect3);
    }
}

/*
 * scan expecting a constant, possibly symbolic
 */
void
scan_num (token *tokp)
{
  get_token (tokp);
  switch (tokp->kind)
    {
    case TOK_IDENT:
      break;
    default:
      error (_("constant or identifier expected"));
    }
}

/*
 * Peek at the next token
 */
void
peek (token *tokp)
{
  get_token (tokp);
  unget_token (tokp);
}

/*
 * Peek at the next token and scan it if it matches what you expect
 */
int
peekscan (tok_kind expect, token *tokp)
{
  peek (tokp);
  if (tokp->kind == expect)
    {
      get_token (tokp);
      return 1;
    }
  return 0;
}

/*
 * Get the next token, printing out any directive that are encountered.
 */
void
get_token (token *tokp)
{
  int commenting;

  if (pushed)
    {
      pushed = 0;
      *tokp = lasttok;
      return;
    }
  commenting = 0;
  for (;;)
    {
      if (*where == 0)
	{
	  for (;;)
	    {
	      if (!fgets (curline, MAXLINESIZE, fin))
		{
		  tokp->kind = TOK_EOF;
		  *curline = 0;
		  where = curline;
		  return;
		}
	      linenum++;
	      if (commenting)
		{
		  break;
		}
	      else if (cppline (curline))
		{
		  docppline (curline, &linenum,
			     &infilename);
		}
	      else if (directive (curline))
		{
		  printdirective (curline);
		}
	      else
		{
		  break;
		}
	    }
	  where = curline;
	}
      else if (isspace (*where))
	{
	  while (isspace (*where))
	    {
	      where++;		/* eat */
	    }
	}
      else if (commenting)
	{
	  for (where++; *where; where++)
	    {
	      if (endcomment (where))
		{
		  where++;
		  commenting--;
		  break;
		}
	    }
	}
      else if (startcomment (where))
	{
	  where += 2;
	  commenting++;
	}
      else
	{
	  break;
	}
    }

  /*
   * 'where' is not whitespace, comment or directive Must be a token!
   */
  switch (*where)
    {
    case ':':
      tokp->kind = TOK_COLON;
      where++;
      break;
    case ';':
      tokp->kind = TOK_SEMICOLON;
      where++;
      break;
    case ',':
      tokp->kind = TOK_COMMA;
      where++;
      break;
    case '=':
      tokp->kind = TOK_EQUAL;
      where++;
      break;
    case '*':
      tokp->kind = TOK_STAR;
      where++;
      break;
    case '[':
      tokp->kind = TOK_LBRACKET;
      where++;
      break;
    case ']':
      tokp->kind = TOK_RBRACKET;
      where++;
      break;
    case '{':
      tokp->kind = TOK_LBRACE;
      where++;
      break;
    case '}':
      tokp->kind = TOK_RBRACE;
      where++;
      break;
    case '(':
      tokp->kind = TOK_LPAREN;
      where++;
      break;
    case ')':
      tokp->kind = TOK_RPAREN;
      where++;
      break;
    case '<':
      tokp->kind = TOK_LANGLE;
      where++;
      break;
    case '>':
      tokp->kind = TOK_RANGLE;
      where++;
      break;

    case '"':
      tokp->kind = TOK_STRCONST;
      findstrconst (&where, &tokp->str);
      break;
    case '\'':
      tokp->kind = TOK_CHARCONST;
      findchrconst (&where, &tokp->str);
      break;

    case '-':
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9':
      tokp->kind = TOK_IDENT;
      findconst (&where, &tokp->str);
      break;

    default:
      if (!(isalpha (*where) || *where == '_'))
	{
	  char buf[100];
	  char *p;

	  s_print (buf, _("illegal character in file: "));
	  p = buf + strlen (buf);
	  if (isprint (*where))
	    {
	      s_print (p, "%c", *where);
	    }
	  else
	    {
	      s_print (p, "%d", *where);
	    }
	  error (buf);
	}
      findkind (&where, tokp);
      break;
    }
}

static void
unget_token (token * tokp)
{
  lasttok = *tokp;
  pushed = 1;
}

static void
findstrconst (const char **str, const char **val)
{
  const char *p;
  char *tmp;
  int size;

  p = *str;
  do
    {
      p++;
    }
  while (*p && *p != '"');
  if (*p == 0)
    {
      error (_("unterminated string constant"));
    }
  p++;
  size = p - *str;
  tmp = alloc (size + 1);
  strncpy (tmp, *str, size);
  tmp[size] = 0;
  *val = tmp;
  *str = p;
}

static void
findchrconst (const char **str, const char **val)
{
  const char *p;
  char *tmp;
  int size;

  p = *str;
  do
    {
      p++;
    }
  while (*p && *p != '\'');
  if (*p == 0)
    {
      error (_("unterminated string constant"));
    }
  p++;
  size = p - *str;
  if (size != 3)
    {
      error (_("empty char string"));
    }
  tmp = alloc (size + 1);
  strncpy (tmp, *str, size);
  tmp[size] = 0;
  *val = tmp;
  *str = p;
}

static void
findconst (const char **str, const char **val)
{
  const char *p;
  char *tmp;
  int size;

  p = *str;
  if (*p == '0' && *(p + 1) == 'x')
    {
      p++;
      do
	{
	  p++;
	}
      while (isxdigit (*p));
    }
  else
    {
      do
	{
	  p++;
	}
      while (isdigit (*p));
    }
  size = p - *str;
  tmp = alloc (size + 1);
  strncpy (tmp, *str, size);
  tmp[size] = 0;
  *val = tmp;
  *str = p;
}

static const token symbols[] =
{
  {TOK_CONST, "const"},
  {TOK_UNION, "union"},
  {TOK_SWITCH, "switch"},
  {TOK_CASE, "case"},
  {TOK_DEFAULT, "default"},
  {TOK_STRUCT, "struct"},
  {TOK_TYPEDEF, "typedef"},
  {TOK_ENUM, "enum"},
  {TOK_OPAQUE, "opaque"},
  {TOK_BOOL, "bool"},
  {TOK_VOID, "void"},
  {TOK_CHAR, "char"},
  {TOK_INT, "int"},
  {TOK_UNSIGNED, "unsigned"},
  {TOK_SHORT, "short"},
  {TOK_LONG, "long"},
  {TOK_HYPER, "hyper"},
  {TOK_FLOAT, "float"},
  {TOK_DOUBLE, "double"},
  {TOK_STRING, "string"},
  {TOK_PROGRAM, "program"},
  {TOK_VERSION, "version"},
  {TOK_EOF, "??????"},
};

static void
findkind (const char **mark, token *tokp)
{
  int len;
  const token *s;
  const char *str;
  char *tmp;

  str = *mark;
  for (s = symbols; s->kind != TOK_EOF; s++)
    {
      len = strlen (s->str);
      if (strncmp (str, s->str, len) == 0)
	{
	  if (!isalnum (str[len]) && str[len] != '_')
	    {
	      tokp->kind = s->kind;
	      tokp->str = s->str;
	      *mark = str + len;
	      return;
	    }
	}
    }
  tokp->kind = TOK_IDENT;
  for (len = 0; isalnum (str[len]) || str[len] == '_'; len++);
  tmp = alloc (len + 1);
  strncpy (tmp, str, len);
  tmp[len] = 0;
  tokp->str = tmp;
  *mark = str + len;
}

static int
cppline (const char *line)
{
  return line == curline && *line == '#';
}

static int
directive (const char *line)
{
  return line == curline && *line == '%';
}

static void
printdirective (const char *line)
{
  f_print (fout, "%s", line + 1);
}

static void
docppline (const char *line, int *lineno, const char **fname)
{
  char *file;
  int num;
  char *p;

  line++;
  while (isspace (*line))
    {
      line++;
    }
  num = atoi (line);
  while (isdigit (*line))
    {
      line++;
    }
  while (isspace (*line))
    {
      line++;
    }
  if (*line != '"')
    {
      error (_("preprocessor error"));
    }
  line++;
  p = file = alloc (strlen (line) + 1);
  while (*line && *line != '"')
    {
      *p++ = *line++;
    }
  if (*line == 0)
    {
      error (_("preprocessor error"));
    }
  *p = 0;
  if (*file == 0)
    {
      free (file);
      *fname = NULL;
    }
  else
    {
      *fname = file;
    }
  *lineno = num - 1;
}
