X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/0d6508efab13d47fb08e9b49a90579abfb3a6d20..ea6cfe9ebd960e2cb4573c2c6f02b02931ac1f86:/src/lex.c?ds=sidebyside

diff --git a/src/lex.c b/src/lex.c
index 371fbed9..489fdf9c 100644
--- a/src/lex.c
+++ b/src/lex.c
@@ -1,5 +1,5 @@
 /* Token-reader for Bison's input parser,
-   Copyright 1984, 1986, 1989, 1992, 2000 Free Software Foundation, Inc.
+   Copyright 1984, 1986, 1989, 1992, 2000, 2001 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -21,43 +21,37 @@
 #include "system.h"
 #include "getargs.h"
 #include "files.h"
-#include "getopt.h"		/* for optarg */
 #include "symtab.h"
+#include "options.h"
 #include "lex.h"
-#include "xalloc.h"
 #include "complain.h"
 #include "gram.h"
 #include "quote.h"
 
 /* Buffer for storing the current token.  */
-char *token_buffer;
+static struct obstack token_obstack;
+const char *token_buffer = NULL;
 
-/* Allocated size of token_buffer, not including space for terminator.  */
-static int maxtoken;
-
-bucket *symval;
+bucket *symval = NULL;
 int numval;
 
-static int unlexed;		/* these two describe a token to be reread */
-static bucket *unlexed_symval;	/* by the next call to lex */
-
+/* A token to be reread, see unlex and lex. */
+static token_t unlexed = tok_undef;
+static bucket *unlexed_symval = NULL;
+static const char *unlexed_token_buffer = NULL;
 
 void
-init_lex (void)
+lex_init (void)
 {
-  maxtoken = 100;
-  token_buffer = XCALLOC (char, maxtoken + 1);
-  unlexed = -1;
+  obstack_init (&token_obstack);
+  unlexed = tok_undef;
 }
 
 
-static char *
-grow_token_buffer (char *p)
+void
+lex_free (void)
 {
-  int offset = p - token_buffer;
-  maxtoken *= 2;
-  token_buffer = XREALLOC (token_buffer, char, maxtoken + 1);
-  return token_buffer + offset;
+  obstack_free (&token_obstack, NULL);
 }
 
 
@@ -136,7 +130,7 @@ skip_white_space (void)
 | Do a getc, but give error message if EOF encountered |
 `-----------------------------------------------------*/
 
-static int
+int
 xgetc (FILE *f)
 {
   int c = getc (f);
@@ -146,69 +140,62 @@ xgetc (FILE *f)
 }
 
 
-/*------------------------------------------------------------------.
-| Read one literal character from finput.  Process \ escapes.       |
-| Append the normalized string version of the char to *PP.  Assign  |
-| the character code to *PCODE. Return 1 unless the character is an |
-| unescaped `term' or \n report error for \n                        |
-`------------------------------------------------------------------*/
+/*---------------------------------------------------------------.
+| Read one literal character from FINPUT, process \-escapes, and |
+| return the character.                                          |
+`---------------------------------------------------------------*/
 
-static int
-literalchar (char **pp, int *pcode, char term)
+char
+literalchar (void)
 {
   int c;
-  char *p;
-  int code;
-  int wasquote = 0;
+  int res;
 
   c = xgetc (finput);
   if (c == '\n')
     {
       complain (_("unescaped newline in constant"));
       ungetc (c, finput);
-      code = '?';
-      wasquote = 1;
+      res = '?';
     }
   else if (c != '\\')
     {
-      code = c;
-      if (c == term)
-	wasquote = 1;
+      res = c;
     }
   else
     {
       c = xgetc (finput);
       if (c == 't')
-	code = '\t';
+	res = '\t';
       else if (c == 'n')
-	code = '\n';
+	res = '\n';
       else if (c == 'a')
-	code = '\007';
+	res = '\007';
       else if (c == 'r')
-	code = '\r';
+	res = '\r';
       else if (c == 'f')
-	code = '\f';
+	res = '\f';
       else if (c == 'b')
-	code = '\b';
+	res = '\b';
       else if (c == 'v')
-	code = '\013';
+	res = '\013';
       else if (c == '\\')
-	code = '\\';
+	res = '\\';
       else if (c == '\'')
-	code = '\'';
+	res = '\'';
       else if (c == '\"')
-	code = '\"';
+	res = '\"';
       else if (c <= '7' && c >= '0')
 	{
-	  code = 0;
+	  res = 0;
 	  while (c <= '7' && c >= '0')
 	    {
-	      code = (code * 8) + (c - '0');
-	      if (code >= 256 || code < 0)
+	      res = (res * 8) + (c - '0');
+	      if (res >= 256 || res < 0)
 		{
 		  complain (_("octal value outside range 0...255: `\\%o'"),
-			    code);
-		  code &= 0xFF;
+			    res);
+		  res &= 0xFF;
 		  break;
 		}
 	      c = xgetc (finput);
@@ -218,21 +205,21 @@ literalchar (char **pp, int *pcode, char term)
       else if (c == 'x')
 	{
 	  c = xgetc (finput);
-	  code = 0;
+	  res = 0;
 	  while (1)
 	    {
 	      if (c >= '0' && c <= '9')
-		code *= 16, code += c - '0';
+		res *= 16, res += c - '0';
 	      else if (c >= 'a' && c <= 'f')
-		code *= 16, code += c - 'a' + 10;
+		res *= 16, res += c - 'a' + 10;
 	      else if (c >= 'A' && c <= 'F')
-		code *= 16, code += c - 'A' + 10;
+		res *= 16, res += c - 'A' + 10;
 	      else
 		break;
-	      if (code >= 256 || code < 0)
+	      if (res >= 256 || res < 0)
 		{
-		  complain (_("hexadecimal value above 255: `\\x%x'"), code);
-		  code &= 0xFF;
+		  complain (_("hexadecimal value above 255: `\\x%x'"), res);
+		  res &= 0xFF;
 		  break;
 		}
 	      c = xgetc (finput);
@@ -241,85 +228,23 @@ literalchar (char **pp, int *pcode, char term)
 	}
       else
 	{
-	  char buf [] = "c";
-	  buf[0] = c;
+	  char badchar [] = "c";
+	  badchar[0] = c;
 	  complain (_("unknown escape sequence: `\\' followed by `%s'"),
-		    quote (buf));
-	  code = '?';
+		    quote (badchar));
+	  res = '?';
 	}
     }				/* has \ */
 
-  /* now fill token_buffer with the canonical name for this character
-     as a literal token.  Do not use what the user typed,
-     so that `\012' and `\n' can be interchangeable.  */
-
-  p = *pp;
-  if (code == term && wasquote)
-    *p++ = code;
-  else if (code == '\\')
-    {
-      *p++ = '\\';
-      *p++ = '\\';
-    }
-  else if (code == '\'')
-    {
-      *p++ = '\\';
-      *p++ = '\'';
-    }
-  else if (code == '\"')
-    {
-      *p++ = '\\';
-      *p++ = '\"';
-    }
-  else if (code >= 040 && code < 0177)
-    *p++ = code;
-  else if (code == '\t')
-    {
-      *p++ = '\\';
-      *p++ = 't';
-    }
-  else if (code == '\n')
-    {
-      *p++ = '\\';
-      *p++ = 'n';
-    }
-  else if (code == '\r')
-    {
-      *p++ = '\\';
-      *p++ = 'r';
-    }
-  else if (code == '\v')
-    {
-      *p++ = '\\';
-      *p++ = 'v';
-    }
-  else if (code == '\b')
-    {
-      *p++ = '\\';
-      *p++ = 'b';
-    }
-  else if (code == '\f')
-    {
-      *p++ = '\\';
-      *p++ = 'f';
-    }
-  else
-    {
-      *p++ = '\\';
-      *p++ = code / 0100 + '0';
-      *p++ = ((code / 010) & 07) + '0';
-      *p++ = (code & 07) + '0';
-    }
-  *pp = p;
-  *pcode = code;
-  return !wasquote;
+  return res;
 }
 
 
 void
-unlex (int token)
+unlex (token_t token)
 {
   unlexed = token;
+  unlexed_token_buffer = token_buffer;
   unlexed_symval = symval;
 }
 
@@ -331,7 +256,6 @@ unlex (int token)
 void
 read_type_name (FILE *fin)
 {
-  char *p = token_buffer;
   int c = getc (fin);
 
   while (c != '>')
@@ -345,40 +269,38 @@ read_type_name (FILE *fin)
 	  break;
 	}
 
-      if (p == token_buffer + maxtoken)
-	p = grow_token_buffer (p);
-
-      *p++ = c;
+      obstack_1grow (&token_obstack, c);
       c = getc (fin);
     }
-  *p = 0;
+  obstack_1grow (&token_obstack, '\0');
+  token_buffer = obstack_finish (&token_obstack);
 }
 
 
-int
+token_t
 lex (void)
 {
   int c;
-  char *p;
 
-  if (unlexed >= 0)
+  /* Just to make sure. */
+  token_buffer = NULL;
+
+  if (unlexed != tok_undef)
     {
+      token_t res = unlexed;
       symval = unlexed_symval;
-      c = unlexed;
-      unlexed = -1;
-      return c;
+      token_buffer = unlexed_token_buffer;
+      unlexed = tok_undef;
+      return res;
     }
 
   c = skip_white_space ();
-  /* for error messages (token buffer always valid) */
-  *token_buffer = c;
-  token_buffer[1] = 0;
 
   switch (c)
     {
     case EOF:
-      strcpy (token_buffer, "EOF");
-      return ENDFILE;
+      token_buffer = "EOF";
+      return tok_eof;
 
     case 'A':    case 'B':    case 'C':    case 'D':    case 'E':
     case 'F':    case 'G':    case 'H':    case 'I':    case 'J':
@@ -394,267 +316,293 @@ lex (void)
     case 'z':
     case '.':    case '_':
 
-      p = token_buffer;
       while (isalnum (c) || c == '_' || c == '.')
 	{
-	  if (p == token_buffer + maxtoken)
-	    p = grow_token_buffer (p);
-
-	  *p++ = c;
+	  obstack_1grow (&token_obstack, c);
 	  c = getc (finput);
 	}
-
-      *p = 0;
+      obstack_1grow (&token_obstack, '\0');
+      token_buffer = obstack_finish (&token_obstack);
       ungetc (c, finput);
       symval = getsym (token_buffer);
-      return IDENTIFIER;
+      return tok_identifier;
 
     case '0':    case '1':    case '2':    case '3':    case '4':
     case '5':    case '6':    case '7':    case '8':    case '9':
       {
 	numval = 0;
 
-	p = token_buffer;
 	while (isdigit (c))
 	  {
-	    if (p == token_buffer + maxtoken)
-	      p = grow_token_buffer (p);
-
-	    *p++ = c;
+	    obstack_1grow (&token_obstack, c);
 	    numval = numval * 10 + c - '0';
 	    c = getc (finput);
 	  }
-	*p = 0;
+	obstack_1grow (&token_obstack, '\0');
+	token_buffer = obstack_finish (&token_obstack);
 	ungetc (c, finput);
-	return NUMBER;
+	return tok_number;
       }
 
     case '\'':
       /* parse the literal token and compute character code in  code  */
 
-      translations = -1;
       {
-	int code, discode;
-	char discard[10], *dp;
+	int code = literalchar ();
 
-	p = token_buffer;
-	*p++ = '\'';
-	literalchar (&p, &code, '\'');
+	obstack_1grow (&token_obstack, '\'');
+	obstack_1grow (&token_obstack, code);
 
 	c = getc (finput);
 	if (c != '\'')
 	  {
 	    complain (_("use \"...\" for multi-character literal tokens"));
-	    while (1)
-	      {
-		dp = discard;
-		if (!literalchar (&dp, &discode, '\''))
-		  break;
-	      }
+	    while (literalchar () != '\'')
+	      /* Skip. */;
 	  }
-	*p++ = '\'';
-	*p = 0;
+	obstack_1grow (&token_obstack, '\'');
+	obstack_1grow (&token_obstack, '\0');
+	token_buffer = obstack_finish (&token_obstack);
 	symval = getsym (token_buffer);
 	symval->class = token_sym;
-	if (!symval->user_token_number)
+	if (symval->user_token_number == SUNDEF)
 	  symval->user_token_number = code;
-	return IDENTIFIER;
+	return tok_identifier;
       }
 
     case '\"':
       /* parse the literal string token and treat as an identifier */
 
-      translations = -1;
       {
 	int code;		/* ignored here */
-	p = token_buffer;
-	*p++ = '\"';
+
+	obstack_1grow (&token_obstack, '\"');
 	/* Read up to and including ".  */
-	while (literalchar (&p, &code, '\"'))
+	do
 	  {
-	    if (p >= token_buffer + maxtoken - 4)
-	      p = grow_token_buffer (p);
+	    code = literalchar ();
+	    obstack_1grow (&token_obstack, code);
 	  }
-	*p = 0;
+	while (code != '\"');
+	obstack_1grow (&token_obstack, '\0');
+	token_buffer = obstack_finish (&token_obstack);
 
 	symval = getsym (token_buffer);
 	symval->class = token_sym;
 
-	return IDENTIFIER;
+	return tok_identifier;
       }
 
     case ',':
-      return COMMA;
+      token_buffer = ",";
+      return tok_comma;
 
     case ':':
-      return COLON;
+      token_buffer = ":";
+      return tok_colon;
 
     case ';':
-      return SEMICOLON;
+      token_buffer = ";";
+      return tok_semicolon;
 
     case '|':
-      return BAR;
+      token_buffer = "|";
+      return tok_bar;
 
     case '{':
-      return LEFT_CURLY;
+      token_buffer = "{";
+      return tok_left_curly;
 
     case '=':
+      obstack_1grow (&token_obstack, c);
       do
 	{
 	  c = getc (finput);
+	  obstack_1grow (&token_obstack, c);
 	  if (c == '\n')
 	    lineno++;
 	}
       while (c == ' ' || c == '\n' || c == '\t');
+      obstack_1grow (&token_obstack, '\0');
+      token_buffer = obstack_finish (&token_obstack);
 
       if (c == '{')
 	{
-	  strcpy (token_buffer, "={");
-	  return LEFT_CURLY;
+	  return tok_left_curly;
 	}
       else
 	{
 	  ungetc (c, finput);
-	  return ILLEGAL;
+	  return tok_illegal;
 	}
 
     case '<':
       read_type_name (finput);
-      return TYPENAME;
+      return tok_typename;
 
     case '%':
       return parse_percent_token ();
 
     default:
-      return ILLEGAL;
+      obstack_1grow (&token_obstack, c);
+      obstack_1grow (&token_obstack, '\0');
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_illegal;
     }
 }
 
-/* the following table dictates the action taken for the various %
-   directives.  A set_flag value causes the named flag to be set.  A
-   retval action returns the code.  */
-struct percent_table_struct
-{
-  const char *name;
-  void *set_flag;
-  int retval;
-};
+/* This function is a strcmp, which doesn't differentiate `-' and `_'
+   chars.  */
 
-struct percent_table_struct percent_table[] =
+static int
+option_strcmp (const char *left, const char *right)
 {
-  { "token",		NULL,			TOKEN },
-  { "term",		NULL,			TOKEN },
-  { "nterm",		NULL,			NTERM },
-  { "type",		NULL,			TYPE },
-  { "guard",		NULL,			GUARD },
-  { "union",		NULL,			UNION },
-  { "expect",		NULL,			EXPECT },
-  { "thong",		NULL,			THONG },
-  { "start",		NULL,			START },
-  { "left",		NULL,			LEFT },
-  { "right",		NULL,			RIGHT },
-  { "nonassoc",		NULL,			NONASSOC },
-  { "binary",		NULL,			NONASSOC },
-  { "prec",		NULL,			PREC },
-  { "locations",	&locations_flag,	NOOP },		/* -l */
-  { "no_lines",		&no_lines_flag,		NOOP },		/* -l */
-  { "raw",		&raw_flag,		NOOP },		/* -r */
-  { "token_table",	&token_table_flag,	NOOP },		/* -k */
-  { "yacc",		&yacc_flag,		NOOP },		/* -y */
-  { "fixed_output_files",&yacc_flag,		NOOP },		/* -y */
-  { "defines",		&defines_flag,		NOOP },		/* -d */
-  { "no_parser",	&no_parser_flag,	NOOP },		/* -n */
-#if 0
-  /* For the time being, this is not enabled yet, while it's possible
-     though, since we use obstacks.  The only risk is with semantic
-     parsers which will output an `include' of an output file: be sure
-     that the naem included is indeed the name of the output file.  */
-  { "output_file",	&spec_outfile,		SETOPT },	/* -o */
-  { "file_prefix",	&spec_file_prefix,	SETOPT },	/* -b */
-  { "name_prefix",	&spec_name_prefix,	SETOPT },	/* -p */
-#endif
-  { "verbose",		&verbose_flag,		NOOP },		/* -v */
-  { "debug",		&debug_flag,		NOOP },		/* -t */
-  { "semantic_parser",	&semantic_parser,	NOOP },
-  { "pure_parser",	&pure_parser,		NOOP },
-/*    {"help", <print usage stmt>, NOOP}, *//* -h */
-/*    {"version", <print version number> ,  NOOP}, *//* -V */
-  { NULL, NULL, ILLEGAL}
-};
+  const unsigned char *l, *r;
+  int c;
+
+  assert (left);
+  assert (right);
+  l = (const unsigned char *)left;
+  r = (const unsigned char *)right;
+  while (((c = *l - *r++) == 0 && *l != '\0')
+	 || ((*l == '-' || *l == '_') && (*r == '_' || *r == '-')))
+    l++;
+  return c;
+}
 
 /* Parse a token which starts with %.
    Assumes the % has already been read and discarded.  */
 
-int
+token_t
 parse_percent_token (void)
 {
-  int c;
-  char *p;
-  struct percent_table_struct *tx;
+  const struct option_table_struct *tx = NULL;
+  const char *arg = NULL;
+  /* Where the ARG was found in token_buffer. */
+  size_t arg_offset = 0;
 
-  p = token_buffer;
-  c = getc (finput);
-  *p++ = '%';
-  *p++ = c;			/* for error msg */
-  *p = 0;
+  int c = getc (finput);
+  obstack_1grow (&token_obstack, '%');
+  obstack_1grow (&token_obstack, c);
 
   switch (c)
     {
     case '%':
-      return TWO_PERCENTS;
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_two_percents;
 
     case '{':
-      return PERCENT_LEFT_CURLY;
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_percent_left_curly;
 
+      /* The following guys are here for backward compatibility with
+	 very ancient Yacc versions.  The paper of Johnson mentions
+	 them (as ancient :).  */
     case '<':
-      return LEFT;
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_left;
 
     case '>':
-      return RIGHT;
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_right;
 
     case '2':
-      return NONASSOC;
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_nonassoc;
 
     case '0':
-      return TOKEN;
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_token;
 
     case '=':
-      return PREC;
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_prec;
     }
+
   if (!isalpha (c))
-    return ILLEGAL;
+    {
+      token_buffer = obstack_finish (&token_obstack);
+      return tok_illegal;
+    }
 
-  p = token_buffer;
-  *p++ = '%';
-  while (isalpha (c) || c == '_' || c == '-')
+  while (c = getc (finput), isalpha (c) || c == '_' || c == '-')
     {
-      if (p == token_buffer + maxtoken)
-	p = grow_token_buffer (p);
+      if (c == '_')
+	c = '-';
+      obstack_1grow (&token_obstack, c);
+    }
 
-      if (c == '-')
-	c = '_';
-      *p++ = c;
+  /* %DIRECTIVE="ARG".  Separate into
+     TOKEN_BUFFER = `%DIRECTIVE\0ARG\0'.
+     This is a bit hackish, but once we move to a Bison parser,
+     things will be cleaned up.  */
+  if (c == '=')
+    {
+      /* End of the directive.  We skip the `='. */
+      obstack_1grow (&token_obstack, '\0');
+      /* Fetch the ARG if present. */
       c = getc (finput);
+      if (c == '"')
+	{
+	  int code;
+	  arg_offset = obstack_object_size (&token_obstack);
+	  /* Read up to and including `"'.  Do not append the closing
+	     `"' in the output: it's not part of the ARG.  */
+	  while ((code = literalchar ()) != '"')
+	    obstack_1grow (&token_obstack, code);
+	}
+      /* else: should be an error. */
     }
+  else
+    ungetc (c, finput);
 
-  ungetc (c, finput);
-
-  *p = 0;
+  obstack_1grow (&token_obstack, '\0');
+  token_buffer = obstack_finish (&token_obstack);
+  if (arg_offset)
+    arg = token_buffer + arg_offset;
 
   /* table lookup % directive */
-  for (tx = percent_table; tx->name; tx++)
-    if (strcmp (token_buffer + 1, tx->name) == 0)
+  for (tx = option_table; tx->name; tx++)
+    if ((tx->access == opt_percent || tx->access == opt_both)
+	&& option_strcmp (token_buffer + 1, tx->name) == 0)
       break;
 
-  if (tx->retval == SETOPT)
-    {
-      *((char **) (tx->set_flag)) = optarg;
-      return NOOP;
-    }
-  if (tx->set_flag)
+  if (arg && tx->ret_val != tok_stropt)
+    fatal (_("`%s' supports no argument: %s"), token_buffer, quote (arg));
+
+
+  switch (tx->ret_val)
     {
+    case tok_stropt:
+      assert (tx->set_flag);
+      if (arg)
+	{
+	  /* Keep only the first assignment: command line options have
+	     already been processed, and we want them to have
+	     precedence.  Side effect: if this %-option is used
+	     several times, only the first is honored.  Bah.  */
+	  if (!*((char **) (tx->set_flag)))
+	    *((char **) (tx->set_flag)) = xstrdup (arg);
+	}
+      else
+	fatal (_("`%s' requires an argument"), token_buffer);
+      return tok_noop;
+      break;
+
+    case tok_intopt:
+      assert (tx->set_flag);
       *((int *) (tx->set_flag)) = 1;
-      return NOOP;
+      return tok_noop;
+      break;
+
+    case tok_obsolete:
+      fatal (_("`%s' is no longer supported"), token_buffer);
+      return tok_noop;
+      break;
+
+    default:
+      return tx->ret_val;
+      break;
     }
-  return tx->retval;
+  abort ();
 }