FYI: Exp: literalchar

[Akim Demaille]

Errr, I don't know who wrote this:

  for (;;)
    {
      if (literalchar (NULL, &c, '\"'))
        obstack_1grow (&param_obstack, c);
      else
        break;
    }

but please, let me tell you there does exist other loop flavors than
for (;;)...

Index: ChangeLog
from  Akim Demaille  <address@hidden>

        * src/lex.c (literalchar): Simply return the char you decoded, non
        longer mess around with obstacks and int pointers.
        Adjust all callers.

Index: src/lex.c
===================================================================
RCS file: /cvsroot/bison/bison/src/lex.c,v
retrieving revision 1.48
diff -u -u -r1.48 lex.c
--- src/lex.c 14 Dec 2001 15:39:05 -0000 1.48
+++ src/lex.c 14 Dec 2001 16:01:10 -0000
@@ -140,67 +140,62 @@
 }
 
 
-/*-----------------------------------------------------------------.
-| Read one literal character from FINPUT.  Process \-escapes.      |
-| Append the char to OUT and assign it *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.                                          |
+`---------------------------------------------------------------*/
 
-int
-literalchar (struct obstack *out, int *pcode, char term)
+char
+literalchar (void)
 {
   int c;
-  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);
@@ -210,21 +205,21 @@
       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);
@@ -237,14 +232,11 @@
          badchar[0] = c;
          complain (_("unknown escape sequence: `\\' followed by `%s'"),
                    quote (badchar));
-         code = '?';
+         res = '?';
        }
     }                          /* has \ */
 
-  if (out)
-    obstack_1grow (out, code);
-  *pcode = code;
-  return !wasquote;
+  return res;
 }
 
 
@@ -356,19 +348,17 @@
       /* parse the literal token and compute character code in  code  */
 
       {
-       int code;
+       int code = literalchar ();
 
        obstack_1grow (&token_obstack, '\'');
-       literalchar (&token_obstack, &code, '\'');
+       obstack_1grow (&token_obstack, code);
 
        c = getc (finput);
        if (c != '\'')
          {
-           int discode;
            complain (_("use \"...\" for multi-character literal tokens"));
-           while (1)
-             if (!literalchar (0, &discode, '\''))
-               break;
+           while (literalchar () != '\'')
+             /* Skip. */;
          }
        obstack_1grow (&token_obstack, '\'');
        obstack_1grow (&token_obstack, '\0');
@@ -388,8 +378,12 @@
 
        obstack_1grow (&token_obstack, '\"');
        /* Read up to and including ".  */
-       while (literalchar (&token_obstack, &code, '\"'))
-         /* nothing */;
+       do
+         {
+           code = literalchar ();
+           obstack_1grow (&token_obstack, code);
+         }
+       while (code != '\"');
        obstack_1grow (&token_obstack, '\0');
        token_buffer = obstack_finish (&token_obstack);
 
@@ -543,7 +537,7 @@
          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, '"'))
+         while ((code = literalchar ()) != '"')
            obstack_1grow (&token_obstack, code);
        }
       /* else: should be an error. */
Index: src/lex.h
===================================================================
RCS file: /cvsroot/bison/bison/src/lex.h,v
retrieving revision 1.23
diff -u -u -r1.23 lex.h
--- src/lex.h 28 Nov 2001 22:28:01 -0000 1.23
+++ src/lex.h 14 Dec 2001 16:01:10 -0000
@@ -73,7 +73,7 @@
    entry found.  */
 
 token_t lex PARAMS ((void));
-int literalchar PARAMS ((struct obstack *out, int *pcode, char term));
+char literalchar PARAMS ((void));
 
 token_t parse_percent_token PARAMS ((void));
 
Index: src/reader.c
===================================================================
RCS file: /cvsroot/bison/bison/src/reader.c,v
retrieving revision 1.116
diff -u -u -r1.116 reader.c
--- src/reader.c 13 Dec 2001 11:01:36 -0000 1.116
+++ src/reader.c 14 Dec 2001 16:01:10 -0000
@@ -985,13 +985,8 @@
       return NULL;
     }
 
-  for (;;)
-    {
-      if (literalchar (NULL, &c, '\"'))
-       obstack_1grow (&param_obstack, c);
-      else
-       break;
-    }
+  while ((c = literalchar ()) != '"')
+    obstack_1grow (&param_obstack, c);
 
   obstack_1grow (&param_obstack, '\0');
   param = obstack_finish (&param_obstack);