X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/d7913476c462b480f11e14b6829942f2691c6c01..9b53a24f310acc04e9b7d12eaf667ca6fb5c2b22:/src/lex.c

diff --git a/src/lex.c b/src/lex.c
index abcf199e..78b8a8f3 100644
--- a/src/lex.c
+++ b/src/lex.c
@@ -1,5 +1,5 @@
 /* Token-reader for Bison's input parser,
-   Copyright (C) 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.
 
@@ -21,45 +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"
-
-/* functions from main.c */
-extern char *printable_version PARAMS ((int));
+#include "quote.h"
 
 /* Buffer for storing the current token.  */
-char *token_buffer;
-
-/* Allocated size of token_buffer, not including space for terminator.  */
-int maxtoken;
+static struct obstack token_obstack;
+const char *token_buffer = NULL;
 
-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;
 }
 
 
-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);
 }
 
 
@@ -78,6 +70,7 @@ skip_white_space (void)
       switch (c)
 	{
 	case '/':
+	  /* FIXME: Should probably be merged with copy_comment.  */
 	  c = getc (finput);
 	  if (c != '*' && c != '/')
 	    {
@@ -132,7 +125,11 @@ skip_white_space (void)
     }
 }
 
-/* do a getc, but give error message if EOF encountered */
+
+/*-----------------------------------------------------.
+| Do a getc, but give error message if EOF encountered |
+`-----------------------------------------------------*/
+
 static int
 xgetc (FILE *f)
 {
@@ -145,16 +142,22 @@ xgetc (FILE *f)
 
 /*------------------------------------------------------------------.
 | Read one literal character from finput.  Process \ escapes.       |
-| Append the normalized string version of the char to *PP.  Assign  |
+| Append the normalized string version of the char to OUT.  Assign  |
 | the character code to *PCODE. Return 1 unless the character is an |
-| unescaped `term' or \n report error for \n                        |
+| unescaped `term' or \n report error for \n.                       |
 `------------------------------------------------------------------*/
 
-static int
-literalchar (char **pp, int *pcode, char term)
+/* FIXME: We could directly work in the obstack, but that would make
+   it more difficult to move to quotearg some day.  So for the time
+   being, I prefer have literalchar behave like quotearg, and change
+   my mind later if I was wrong.  */
+
+int
+literalchar (struct obstack *out, int *pcode, char term)
 {
   int c;
-  char *p;
+  char buf[4096];
+  char *cp;
   int code;
   int wasquote = 0;
 
@@ -238,110 +241,145 @@ literalchar (char **pp, int *pcode, char term)
 	}
       else
 	{
+	  char badchar [] = "c";
+	  badchar[0] = c;
 	  complain (_("unknown escape sequence: `\\' followed by `%s'"),
-		    printable_version (c));
+		    quote (badchar));
 	  code = '?';
 	}
     }				/* 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.  */
+  /* now fill BUF 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;
+  cp = buf;
   if (code == term && wasquote)
-    *p++ = code;
+    *cp++ = code;
   else if (code == '\\')
     {
-      *p++ = '\\';
-      *p++ = '\\';
+      *cp++ = '\\';
+      *cp++ = '\\';
     }
   else if (code == '\'')
     {
-      *p++ = '\\';
-      *p++ = '\'';
+      *cp++ = '\\';
+      *cp++ = '\'';
     }
   else if (code == '\"')
     {
-      *p++ = '\\';
-      *p++ = '\"';
+      *cp++ = '\\';
+      *cp++ = '\"';
     }
   else if (code >= 040 && code < 0177)
-    *p++ = code;
+    *cp++ = code;
   else if (code == '\t')
     {
-      *p++ = '\\';
-      *p++ = 't';
+      *cp++ = '\\';
+      *cp++ = 't';
     }
   else if (code == '\n')
     {
-      *p++ = '\\';
-      *p++ = 'n';
+      *cp++ = '\\';
+      *cp++ = 'n';
     }
   else if (code == '\r')
     {
-      *p++ = '\\';
-      *p++ = 'r';
+      *cp++ = '\\';
+      *cp++ = 'r';
     }
   else if (code == '\v')
     {
-      *p++ = '\\';
-      *p++ = 'v';
+      *cp++ = '\\';
+      *cp++ = 'v';
     }
   else if (code == '\b')
     {
-      *p++ = '\\';
-      *p++ = 'b';
+      *cp++ = '\\';
+      *cp++ = 'b';
     }
   else if (code == '\f')
     {
-      *p++ = '\\';
-      *p++ = 'f';
+      *cp++ = '\\';
+      *cp++ = 'f';
     }
   else
     {
-      *p++ = '\\';
-      *p++ = code / 0100 + '0';
-      *p++ = ((code / 010) & 07) + '0';
-      *p++ = (code & 07) + '0';
+      *cp++ = '\\';
+      *cp++ = code / 0100 + '0';
+      *cp++ = ((code / 010) & 07) + '0';
+      *cp++ = (code & 07) + '0';
     }
-  *pp = p;
+  *cp = '\0';
+
+  if (out)
+    obstack_sgrow (out, buf);
   *pcode = code;
   return !wasquote;
 }
 
 
 void
-unlex (int token)
+unlex (token_t token)
 {
   unlexed = token;
+  unlexed_token_buffer = token_buffer;
   unlexed_symval = symval;
 }
 
+/*-----------------------------------------------------------------.
+| We just read `<' from FIN.  Store in TOKEN_BUFFER, the type name |
+| specified between the `<...>'.                                   |
+`-----------------------------------------------------------------*/
 
-int
+void
+read_type_name (FILE *fin)
+{
+  int c = getc (fin);
+
+  while (c != '>')
+    {
+      if (c == EOF)
+	fatal (_("unterminated type name at end of file"));
+      if (c == '\n')
+	{
+	  complain (_("unterminated type name"));
+	  ungetc (c, fin);
+	  break;
+	}
+
+      obstack_1grow (&token_obstack, c);
+      c = getc (fin);
+    }
+  obstack_1grow (&token_obstack, '\0');
+  token_buffer = obstack_finish (&token_obstack);
+}
+
+
+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 ();
-  *token_buffer = c;		/* for error messages (token buffer always valid) */
-  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':
@@ -357,285 +395,280 @@ 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;
 
-	p = token_buffer;
-	*p++ = '\'';
-	literalchar (&p, &code, '\'');
+	obstack_1grow (&token_obstack, '\'');
+	literalchar (&token_obstack, &code, '\'');
 
 	c = getc (finput);
 	if (c != '\'')
 	  {
+	    int discode;
 	    complain (_("use \"...\" for multi-character literal tokens"));
 	    while (1)
-	      {
-		dp = discard;
-		if (!literalchar (&dp, &discode, '\''))
-		  break;
-	      }
+	      if (!literalchar (0, &discode, '\''))
+		break;
 	  }
-	*p++ = '\'';
-	*p = 0;
+	obstack_1grow (&token_obstack, '\'');
+	obstack_1grow (&token_obstack, '\0');
+	token_buffer = obstack_finish (&token_obstack);
 	symval = getsym (token_buffer);
-	symval->class = STOKEN;
-	if (!symval->user_token_number)
+	symval->class = token_sym;
+	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++ = '\"';
-	while (literalchar (&p, &code, '\"'))	/* read up to and including " */
-	  {
-	    if (p >= token_buffer + maxtoken - 4)
-	      p = grow_token_buffer (p);
-	  }
-	*p = 0;
+
+	obstack_1grow (&token_obstack, '\"');
+	/* Read up to and including ".  */
+	while (literalchar (&token_obstack, &code, '\"'))
+	  /* nothing */;
+	obstack_1grow (&token_obstack, '\0');
+	token_buffer = obstack_finish (&token_obstack);
 
 	symval = getsym (token_buffer);
-	symval->class = STOKEN;
+	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 '<':
-      p = token_buffer;
-      c = getc (finput);
-      while (c != '>')
-	{
-	  if (c == EOF)
-	    fatal (_("unterminated type name at end of file"));
-	  if (c == '\n')
-	    {
-	      complain (_("unterminated type name"));
-	      ungetc (c, finput);
-	      break;
-	    }
-
-	  if (p == token_buffer + maxtoken)
-	    p = grow_token_buffer (p);
-
-	  *p++ = c;
-	  c = getc (finput);
-	}
-      *p = 0;
-      return TYPENAME;
-
+      read_type_name (finput);
+      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 setflag value causes the named flag to be set.  A
-   retval action returns the code.  */
-struct percent_table_struct
+/* This function is a strcmp, which doesn't differentiate `-' and `_'
+   chars.  */
+
+static int
+option_strcmp (const char *left, const char *right)
 {
-  const char *name;
-  void *setflag;
-  int retval;
+  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;
 }
-percent_table[] =
-{
-  { "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 },
-  { "semantic_parser", NULL, SEMANTIC_PARSER },
-  { "pure_parser", NULL, PURE_PARSER },
-  { "prec", NULL, PREC },
-  { "no_lines", &nolinesflag, NOOP},	/* -l */
-  { "raw", &rawtoknumflag, NOOP },	/* -r */
-  { "token_table", &toknumflag, NOOP},	/* -k */
-#if 0
-    /* These can be utilized after main is reoganized so
-       open_files() is deferred 'til after read_declarations().
-       But %{ and %union both put information into files
-       that have to be opened before read_declarations().
-     */
-  { "yacc", &fixed_outfiles, NOOP},			/* -y */
-  { "fixed_output_files", &fixed_outfiles, NOOP},	/* -y */
-  { "defines", &definesflag, NOOP},			/* -d */
-  { "no_parser", &noparserflag, NOOP},			/* -n */
-  { "output_file", &spec_outfile, SETOPT},		/* -o */
-  { "file_prefix", &spec_file_prefix, SETOPT},		/* -b */
-  { "name_prefix", &spec_name_prefix, SETOPT},		/* -p */
-    /* These would be acceptable, but they do not affect processing */
-  { "verbose", &verboseflag, NOOP},			/* -v */
-  { "debug", &debugflag, NOOP},				/* -t */
-/*    {"help", <print usage stmt>, NOOP}, *//* -h */
-/*    {"version", <print version number> ,  NOOP}, *//* -V */
-#endif
-  { NULL, NULL, ILLEGAL}
-};
 
 /* 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);
 
   switch (c)
     {
     case '%':
-      return TWO_PERCENTS;
+      return tok_two_percents;
 
     case '{':
-      return PERCENT_LEFT_CURLY;
+      return tok_percent_left_curly;
 
+      /* FIXME: Who the heck are those 5 guys!?! `%<' = `%left'!!!
+	 Let's ask for there removal.  */
     case '<':
-      return LEFT;
+      return tok_left;
 
     case '>':
-      return RIGHT;
+      return tok_right;
 
     case '2':
-      return NONASSOC;
+      return tok_nonassoc;
 
     case '0':
-      return TOKEN;
+      return tok_token;
 
     case '=':
-      return PREC;
+      return tok_prec;
     }
+
   if (!isalpha (c))
-    return ILLEGAL;
+    return tok_illegal;
 
-  p = token_buffer;
-  *p++ = '%';
+  obstack_1grow (&token_obstack, '%');
   while (isalpha (c) || c == '_' || c == '-')
     {
-      if (p == token_buffer + maxtoken)
-	p = grow_token_buffer (p);
-
-      if (c == '-')
-	c = '_';
-      *p++ = c;
+      if (c == '_')
+	c = '-';
+      obstack_1grow (&token_obstack, c);
       c = getc (finput);
     }
 
-  ungetc (c, finput);
+  /* %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 (literalchar (NULL, &code, '"'))
+	    obstack_1grow (&token_obstack, code);
+	}
+      /* else: should be an error. */
+    }
+  else
+    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->setflag)) = optarg;
-      return NOOP;
-    }
-  if (tx->setflag)
+
+  if (arg && tx->ret_val != tok_stropt)
+    fatal (_("`%s' supports no argument: %s"), token_buffer, quote (arg));
+
+
+  switch (tx->ret_val)
     {
-      *((int *) (tx->setflag)) = 1;
-      return NOOP;
+    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 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 ();
 }