/* rclex.c -- lexer for Windows rc files parser  */

/* Copyright (C) 1997-2020 Free Software Foundation, Inc.

   Written by Kai Tietz, Onevision.

   This file is part of GNU Binutils.

   This program 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 of the License, or
   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
   02110-1301, USA.  */


/* This is a lexer used by the Windows rc file parser.  It basically
   just recognized a bunch of keywords.  */

#include "sysdep.h"
#include "bfd.h"
#include "bucomm.h"
#include "libiberty.h"
#include "safe-ctype.h"
#include "windres.h"
#include "rcparse.h"

#include <assert.h>

/* Whether we are in rcdata mode, in which we returns the lengths of
   strings.  */

static int rcdata_mode;

/* Whether we are suppressing lines from cpp (including windows.h or
   headers from your C sources may bring in externs and typedefs).
   When active, we return IGNORED_TOKEN, which lets us ignore these
   outside of resource constructs.  Thus, it isn't required to protect
   all the non-preprocessor lines in your header files with #ifdef
   RC_INVOKED.  It also means your RC file can't include other RC
   files if they're named "*.h".  Sorry.  Name them *.rch or whatever.  */

static int suppress_cpp_data;

#define IGNORE_CPP(x) (suppress_cpp_data ? IGNORED_TOKEN : (x))

/* The first filename we detect in the cpp output.  We use this to
   tell included files from the original file.  */

static char *initial_fn;

/* List of allocated strings.  */

struct alloc_string
{
  struct alloc_string *next;
  char *s;
};

static struct alloc_string *strings;

struct rclex_keywords
{
  const char *name;
  int tok;
};

#define K(KEY)  { #KEY, KEY }
#define KRT(KEY)  { #KEY, RT_##KEY }

static const struct rclex_keywords keywds[] =
{
  K(ACCELERATORS), K(ALT), K(ANICURSOR), K(ANIICON), K(ASCII),
  K(AUTO3STATE), K(AUTOCHECKBOX), K(AUTORADIOBUTTON),
  K(BEDIT), { "BEGIN", BEG }, K(BITMAP), K(BLOCK), K(BUTTON),
  K(CAPTION), K(CHARACTERISTICS), K(CHECKBOX), K(CHECKED),
  K(CLASS), K(COMBOBOX), K(CONTROL), K(CTEXT), K(CURSOR),
  K(DEFPUSHBUTTON), K(DIALOG), K(DIALOGEX), K(DISCARDABLE),
  K(DLGINCLUDE), K(DLGINIT),
  K(EDITTEXT), K(END), K(EXSTYLE),
  K(FILEFLAGS), K(FILEFLAGSMASK), K(FILEOS), K(FILESUBTYPE),
  K(FILETYPE), K(FILEVERSION), K(FIXED), K(FONT), K(FONTDIR),
  K(GRAYED), KRT(GROUP_CURSOR), KRT(GROUP_ICON), K(GROUPBOX),
  K(HEDIT), K(HELP), K(HTML),
  K(ICON), K(IEDIT), K(IMPURE), K(INACTIVE),
  K(LANGUAGE), K(LISTBOX), K(LOADONCALL), K(LTEXT),
  K(MANIFEST), K(MENU), K(MENUBARBREAK), K(MENUBREAK),
  K(MENUEX), K(MENUITEM), K(MESSAGETABLE), K(MOVEABLE),
  K(NOINVERT), K(NOT),
  K(PLUGPLAY), K(POPUP), K(PRELOAD), K(PRODUCTVERSION),
  K(PURE), K(PUSHBOX), K(PUSHBUTTON),
  K(RADIOBUTTON), K(RCDATA), K(RTEXT),
  K(SCROLLBAR), K(SEPARATOR), K(SHIFT), K(STATE3),
  K(STRINGTABLE), K(STYLE),
  K(TOOLBAR),
  K(USERBUTTON),
  K(VALUE), { "VERSION", VERSIONK }, K(VERSIONINFO),
  K(VIRTKEY), K(VXD),
  { NULL, 0 },
};

/* External input stream from resrc */
extern FILE *cpp_pipe;

/* Lexical scanner helpers.  */
static int rclex_lastch = -1;
static size_t rclex_tok_max = 0;
static size_t rclex_tok_pos = 0;
static char *rclex_tok = NULL;

static int
rclex_translatekeyword (const char *key)
{
  if (key && ISUPPER (key[0]))
    {
      const struct rclex_keywords *kw = &keywds[0];

      do
        {
	  if (! strcmp (kw->name, key))
	    return kw->tok;
	  ++kw;
        }
      while (kw->name != NULL);
    }
  return STRING;
}

/* Handle a C preprocessor line.  */

static void
cpp_line (void)
{
  const char *s = rclex_tok;
  int line;
  char *send, *fn;
  size_t len, mlen;

  ++s;
  while (ISSPACE (*s))
    ++s;

  /* Check for #pragma code_page ( DEFAULT | <nr>).  */
  len = strlen (s);
  mlen = strlen ("pragma");
  if (len > mlen && memcmp (s, "pragma", mlen) == 0 && ISSPACE (s[mlen]))
    {
      const char *end;

      s += mlen + 1;
      while (ISSPACE (*s))
	++s;
      len = strlen (s);
      mlen = strlen ("code_page");
      if (len <= mlen || memcmp (s, "code_page", mlen) != 0)
	/* FIXME: We ought to issue a warning message about an unrecognised pragma.  */
	return;
      s += mlen;
      while (ISSPACE (*s))
	++s;
      if (*s != '(')
	/* FIXME: We ought to issue an error message about a malformed pragma.  */
	return;
      ++s;
      while (ISSPACE (*s))
	++s;
      if (*s == 0 || (end = strchr (s, ')')) == NULL)
	/* FIXME: We ought to issue an error message about a malformed pragma.  */
	return;
      len = (size_t) (end - s);
      fn = xmalloc (len + 1);
      if (len)
      	memcpy (fn, s, len);
      fn[len] = 0;
      while (len > 0 && (fn[len - 1] > 0 && fn[len - 1] <= 0x20))
	fn[--len] = 0;
      if (! len || (len == strlen ("DEFAULT") && strcasecmp (fn, "DEFAULT") == 0))
	wind_current_codepage = wind_default_codepage;
      else if (len > 0)
	{
	  rc_uint_type ncp;

	  if (fn[0] == '0' && (fn[1] == 'x' || fn[1] == 'X'))
	      ncp = (rc_uint_type) strtol (fn + 2, NULL, 16);
	  else
	      ncp = (rc_uint_type) strtol (fn, NULL, 10);
	  if (ncp == CP_UTF16 || ! unicode_is_valid_codepage (ncp))
	    fatal (_("invalid value specified for pragma code_page.\n"));
	  wind_current_codepage = ncp;
	}
      free (fn);
      return;
    }

  line = strtol (s, &send, 0);
  if (*send != '\0' && ! ISSPACE (*send))
    return;

  /* Subtract 1 because we are about to count the newline.  */
  rc_lineno = line - 1;

  s = send;
  while (ISSPACE (*s))
    ++s;

  if (*s != '"')
    return;

  ++s;
  send = strchr (s, '"');
  if (send == NULL)
    return;

  fn = xmalloc (send - s + 1);
  strncpy (fn, s, send - s);
  fn[send - s] = '\0';

  free (rc_filename);
  rc_filename = fn;

  if (! initial_fn)
    {
      initial_fn = xmalloc (strlen (fn) + 1);
      strcpy (initial_fn, fn);
    }

  /* Allow the initial file, regardless of name.  Suppress all other
     files if they end in ".h" (this allows included "*.rc").  */
  if (strcmp (initial_fn, fn) == 0
      || strcmp (fn + strlen (fn) - 2, ".h") != 0)
    suppress_cpp_data = 0;
  else
    suppress_cpp_data = 1;
}

/* Allocate a string of a given length.  */

static char *
get_string (int len)
{
  struct alloc_string *as;

  as = xmalloc (sizeof *as);
  as->s = xmalloc (len);

  as->next = strings;
  strings = as;

  return as->s;
}

/* Handle a quoted string.  The quotes are stripped.  A pair of quotes
   in a string are turned into a single quote.  Adjacent strings are
   merged separated by whitespace are merged, as in C.  */

static char *
handle_quotes (rc_uint_type *len)
{
  const char *input = rclex_tok;
  char *ret, *s;
  const char *t;
  int ch;
  int num_xdigits;

  ret = get_string (strlen (input) + 1);

  s = ret;
  t = input;
  if (*t == '"')
    ++t;
  while (*t != '\0')
    {
      if (*t == '\\')
	{
	  ++t;
	  switch (*t)
	    {
	    case '\0':
	      rcparse_warning ("backslash at end of string");
	      break;

	    case '\"':
	      rcparse_warning ("use \"\" to put \" in a string");
	      *s++ = '"';
	      ++t;
	      break;

	    case 'a':
	      *s++ = ESCAPE_B; /* Strange, but true...  */
	      ++t;
	      break;

	    case 'b':
	      *s++ = ESCAPE_B;
	      ++t;
	      break;

	    case 'f':
	      *s++ = ESCAPE_F;
	      ++t;
	      break;

	    case 'n':
	      *s++ = ESCAPE_N;
	      ++t;
	      break;

	    case 'r':
	      *s++ = ESCAPE_R;
	      ++t;
	      break;

	    case 't':
	      *s++ = ESCAPE_T;
	      ++t;
	      break;

	    case 'v':
	      *s++ = ESCAPE_V;
	      ++t;
	      break;

	    case '\\':
	      *s++ = *t++;
	      break;

	    case '0': case '1': case '2': case '3':
	    case '4': case '5': case '6': case '7':
	      ch = *t - '0';
	      ++t;
	      if (*t >= '0' && *t <= '7')
		{
		  ch = (ch << 3) | (*t - '0');
		  ++t;
		  if (*t >= '0' && *t <= '7')
		    {
		      ch = (ch << 3) | (*t - '0');
		      ++t;
		    }
		}
	      *s++ = ch;
	      break;

	    case 'x': case 'X':
	      ++t;
	      ch = 0;
	      /* We only handle single byte chars here.  Make sure
		 we finish an escape sequence like "/xB0ABC" after
		 the first two digits.  */
              num_xdigits = 2;
 	      while (num_xdigits--)
		{
		  if (*t >= '0' && *t <= '9')
		    ch = (ch << 4) | (*t - '0');
		  else if (*t >= 'a' && *t <= 'f')
		    ch = (ch << 4) | (*t - 'a' + 10);
		  else if (*t >= 'A' && *t <= 'F')
		    ch = (ch << 4) | (*t - 'A' + 10);
		  else
		    break;
		  ++t;
		}
	      *s++ = ch;
	      break;

	    default:
	      rcparse_warning ("unrecognized escape sequence");
	      *s++ = '\\';
	      *s++ = *t++;
	      break;
	    }
	}
      else if (*t != '"')
	*s++ = *t++;
      else if (t[1] == '\0')
	break;
      else if (t[1] == '"')
	{
	  *s++ = '"';
	  t += 2;
	}
      else
	{
	  ++t;
	  if (! ISSPACE (*t))
	    rcparse_warning ("unexpected character after '\"'");
	  while (ISSPACE (*t))
	    {
	      if ((*t) == '\n')
		++rc_lineno;
	      ++t;
	    }
	  if (*t == '\0')
	    break;
	  assert (*t == '"');
	  ++t;
	}
    }

  *s = '\0';

  *len = s - ret;

  return ret;
}

/* Allocate a unicode string of a given length.  */

static unichar *
get_unistring (int len)
{
  return (unichar *) get_string (len * sizeof (unichar));
}

/* Handle a quoted unicode string.  The quotes are stripped.  A pair of quotes
   in a string are turned into a single quote.  Adjacent strings are
   merged separated by whitespace are merged, as in C.  */

static unichar *
handle_uniquotes (rc_uint_type *len)
{
  const char *input = rclex_tok;
  unichar *ret, *s;
  const char *t;
  int ch;
  int num_xdigits;

  ret = get_unistring (strlen (input) + 1);

  s = ret;
  t = input;
  if ((*t == 'L' || *t == 'l') && t[1] == '"')
    t += 2;
  else if (*t == '"')
    ++t;
  while (*t != '\0')
    {
      if (*t == '\\')
	{
	  ++t;
	  switch (*t)
	    {
	    case '\0':
	      rcparse_warning ("backslash at end of string");
	      break;

	    case '\"':
	      rcparse_warning ("use \"\" to put \" in a string");
	      break;

	    case 'a':
	      *s++ = ESCAPE_B; /* Strange, but true...  */
	      ++t;
	      break;

	    case 'b':
	      *s++ = ESCAPE_B;
	      ++t;
	      break;

	    case 'f':
	      *s++ = ESCAPE_F;
	      ++t;
	      break;

	    case 'n':
	      *s++ = ESCAPE_N;
	      ++t;
	      break;

	    case 'r':
	      *s++ = ESCAPE_R;
	      ++t;
	      break;

	    case 't':
	      *s++ = ESCAPE_T;
	      ++t;
	      break;

	    case 'v':
	      *s++ = ESCAPE_V;
	      ++t;
	      break;

	    case '\\':
	      *s++ = (unichar) *t++;
	      break;

	    case '0': case '1': case '2': case '3':
	    case '4': case '5': case '6': case '7':
	      ch = *t - '0';
	      ++t;
	      if (*t >= '0' && *t <= '7')
		{
		  ch = (ch << 3) | (*t - '0');
		  ++t;
		  if (*t >= '0' && *t <= '7')
		    {
		      ch = (ch << 3) | (*t - '0');
		      ++t;
		    }
		}
	      *s++ = (unichar) ch;
	      break;

	    case 'x': case 'X':
	      ++t;
	      ch = 0;
	      /* We only handle two byte chars here.  Make sure
		 we finish an escape sequence like "/xB0ABC" after
		 the first two digits.  */
              num_xdigits = 4;
 	      while (num_xdigits--)
		{
		  if (*t >= '0' && *t <= '9')
		    ch = (ch << 4) | (*t - '0');
		  else if (*t >= 'a' && *t <= 'f')
		    ch = (ch << 4) | (*t - 'a' + 10);
		  else if (*t >= 'A' && *t <= 'F')
		    ch = (ch << 4) | (*t - 'A' + 10);
		  else
		    break;
		  ++t;
		}
	      *s++ = (unichar) ch;
	      break;

	    default:
	      rcparse_warning ("unrecognized escape sequence");
	      *s++ = '\\';
	      *s++ = (unichar) *t++;
	      break;
	    }
	}
      else if (*t != '"')
	*s++ = (unichar) *t++;
      else if (t[1] == '\0')
	break;
      else if (t[1] == '"')
	{
	  *s++ = '"';
	  t += 2;
	}
      else
	{
	  ++t;
	  assert (ISSPACE (*t));
	  while (ISSPACE (*t))
	    {
	      if ((*t) == '\n')
		++rc_lineno;
	      ++t;
	    }
	  if (*t == '\0')
	    break;
	  assert (*t == '"');
	  ++t;
	}
    }

  *s = '\0';

  *len = s - ret;

  return ret;
}

/* Discard all the strings we have allocated.  The parser calls this
   when it no longer needs them.  */

void
rcparse_discard_strings (void)
{
  struct alloc_string *as;

  as = strings;
  while (as != NULL)
    {
      struct alloc_string *n;

      free (as->s);
      n = as->next;
      free (as);
      as = n;
    }

  strings = NULL;
}

/* Enter rcdata mode.  */
void
rcparse_rcdata (void)
{
  rcdata_mode = 1;
}

/* Go back to normal mode from rcdata mode.  */
void
rcparse_normal (void)
{
  rcdata_mode = 0;
}

static void
rclex_tok_add_char (int ch)
{
  if (! rclex_tok || rclex_tok_max <= rclex_tok_pos)
    {
      char *h = xmalloc (rclex_tok_max + 9);

      if (! h)
	abort ();
      if (rclex_tok)
	{
	  memcpy (h, rclex_tok, rclex_tok_pos + 1);
	  free (rclex_tok);
	}
      else
	rclex_tok_pos = 0;
      rclex_tok_max += 8;
      rclex_tok = h;
    }
  if (ch != -1)
    rclex_tok[rclex_tok_pos++] = (char) ch;
  rclex_tok[rclex_tok_pos] = 0;
}

static int
rclex_readch (void)
{
  int r = -1;

  if ((r = rclex_lastch) != -1)
    rclex_lastch = -1;
  else
    {
      char ch;
      do
        {
	  if (! cpp_pipe || feof (cpp_pipe)
	      || fread (&ch, 1, 1,cpp_pipe) != 1)
	    break;
	  r = ((int) ch) & 0xff;
        }
      while (r == 0 || r == '\r');
  }
  rclex_tok_add_char (r);
  return r;
}

static int
rclex_peekch (void)
{
  int r;

  if ((r = rclex_lastch) == -1)
    {
      if ((r = rclex_readch ()) != -1)
	{
	  rclex_lastch = r;
	  if (rclex_tok_pos > 0)
	    rclex_tok[--rclex_tok_pos] = 0;
	}
    }
  return r;
}

static void
rclex_string (void)
{
  int c;

  while ((c = rclex_peekch ()) != -1)
    {
      if (c == '\n')
	break;
      if (c == '\\')
        {
	  rclex_readch ();
	  if ((c = rclex_peekch ()) == -1 || c == '\n')
	    break;
	  rclex_readch ();
        }
      else if (rclex_readch () == '"')
	{
	  /* PR 6714
	     Skip any whitespace after the end of the double quotes.  */
	  do
	    {
	      c = rclex_peekch ();
	      if (ISSPACE (c))
		rclex_readch ();
	      else
		c = -1;
	    }
	  while (c != -1);

	  if (rclex_peekch () == '"')
	    rclex_readch ();
	  else
	    break;
	}
    }
}

static rc_uint_type
read_digit (int ch)
{
  rc_uint_type base = 10;
  rc_uint_type ret, val;
  int warned = 0;

  ret = 0;
  if (ch == '0')
    {
      base = 8;
      switch (rclex_peekch ())
	{
	case 'o': case 'O':
	  rclex_readch ();
	  base = 8;
	  break;

	case 'x': case 'X':
	  rclex_readch ();
	  base = 16;
	  break;
	}
    }
  else
    ret = (rc_uint_type) (ch - '0');
  while ((ch = rclex_peekch ()) != -1)
    {
      if (ISDIGIT (ch))
	val = (rc_uint_type) (ch - '0');
      else if (ch >= 'a' && ch <= 'f')
	val = (rc_uint_type) ((ch - 'a') + 10);
      else if (ch >= 'A' && ch <= 'F')
	val = (rc_uint_type) ((ch - 'A') + 10);
      else
	break;
      rclex_readch ();
      if (! warned && val >= base)
	{
	  warned = 1;
	  rcparse_warning ("digit exceeds base");
	}
      ret *= base;
      ret += val;
    }
  return ret;
}

/* yyparser entry method.  */

int
yylex (void)
{
  char *s;
  unichar *us;
  rc_uint_type length;
  int ch;

  /* Make sure that rclex_tok is initialized.  */
  if (! rclex_tok)
    rclex_tok_add_char (-1);

  do
    {
      do
	{
	  /* Clear token.  */
	  rclex_tok_pos = 0;
	  rclex_tok[0] = 0;

	  if ((ch = rclex_readch ()) == -1)
	    return -1;
	  if (ch == '\n')
	    ++rc_lineno;
	}
      while (ch <= 0x20);

      switch (ch)
	{
	case '#':
	  while ((ch = rclex_peekch ()) != -1 && ch != '\n')
	    rclex_readch ();
	  cpp_line ();
	  ch = IGNORED_TOKEN;
	  break;

	case '{':
	  ch = IGNORE_CPP (BEG);
	  break;

	case '}':
	  ch = IGNORE_CPP (END);
	  break;

	case '0': case '1': case '2': case '3': case '4':
	case '5': case '6': case '7': case '8': case '9':
	  yylval.i.val = read_digit (ch);
	  yylval.i.dword = 0;
	  switch (rclex_peekch ())
	    {
	    case 'l': case 'L':
	      rclex_readch ();
	      yylval.i.dword = 1;
	      break;
	    }
	  ch = IGNORE_CPP (NUMBER);
	  break;
	case '"':
	  rclex_string ();
	  ch = IGNORE_CPP ((! rcdata_mode ? QUOTEDSTRING : SIZEDSTRING));
	  if (ch == IGNORED_TOKEN)
	    break;
	  s = handle_quotes (&length);
	  if (! rcdata_mode)
	    yylval.s = s;
	  else
	    {
	      yylval.ss.length = length;
	      yylval.ss.s = s;
	  }
	  break;
	case 'L': case 'l':
	  if (rclex_peekch () == '"')
	    {
	      rclex_readch ();
	      rclex_string ();
	      ch = IGNORE_CPP ((! rcdata_mode ? QUOTEDUNISTRING : SIZEDUNISTRING));
	      if (ch == IGNORED_TOKEN)
		break;
	      us = handle_uniquotes (&length);
	      if (! rcdata_mode)
		yylval.uni = us;
	      else
	        {
		  yylval.suni.length = length;
		  yylval.suni.s = us;
	      }
	      break;
	    }
	  /* Fall through.  */
	default:
	  if (ISIDST (ch) || ch=='$')
	    {
	      while ((ch = rclex_peekch ()) != -1
		     && (ISIDNUM (ch) || ch == '$' || ch == '.'
		         || ch == ':' || ch == '\\' || ch == '/'
		         || ch == '_' || ch == '-')
		    )
		rclex_readch ();
	      ch = IGNORE_CPP (rclex_translatekeyword (rclex_tok));
	      if (ch == STRING)
		{
		  s = get_string (strlen (rclex_tok) + 1);
		  strcpy (s, rclex_tok);
		  yylval.s = s;
		}
	      else if (ch == BLOCK)
		{
		  const char *hs = NULL;

		  switch (yylex ())
		  {
		  case STRING:
		  case QUOTEDSTRING:
		    hs = yylval.s;
		    break;
		  case SIZEDSTRING:
		    hs = yylval.s = yylval.ss.s;
		    break;
		  }
		  if (! hs)
		    {
		      rcparse_warning ("BLOCK expects a string as argument.");
		      ch = IGNORED_TOKEN;
		    }
		  else if (! strcmp (hs, "StringFileInfo"))
		    ch = BLOCKSTRINGFILEINFO;
		  else if (! strcmp (hs, "VarFileInfo"))
		    ch = BLOCKVARFILEINFO;
		}
	      break;
	    }
	  ch = IGNORE_CPP (ch);
	  break;
	}
    }
  while (ch == IGNORED_TOKEN);

  return ch;
}
