[hackers] [scc] Fix character sequences || Roberto E. Vargas Caballero

[git]

commit 1aa2143073c30f374c33e0288135dc3e04494588
Author:     Roberto E. Vargas Caballero <k...@shike2.com>
AuthorDate: Tue Nov 24 20:29:45 2015 +0100
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Tue Nov 24 20:29:45 2015 +0100

    Fix character sequences
    
    Character sequences can apper in strings or in character constants,
    but in these cases the lexer was expecting a different state at the
    end of escape().

diff --git a/cc1/lex.c b/cc1/lex.c
index f4a0d26..2bcdb98 100644
--- a/cc1/lex.c
+++ b/cc1/lex.c
@@ -398,31 +398,43 @@ escape(void)
        int c, base;
 
        switch (*++input->p) {
-       case '\\': c = '\\'; goto escape_letter;
-       case 'a':  c = '\a'; goto escape_letter;
-       case 'f':  c = '\f'; goto escape_letter;
-       case 'n':  c = '\n'; goto escape_letter;
-       case 'r':  c = '\r'; goto escape_letter;
-       case 't':  c = '\t'; goto escape_letter;
-       case 'v':  c = '\v'; goto escape_letter;
-       case '\'': c = '\\'; goto escape_letter;
-       case '"':  c = '"'; goto escape_letter;
-       case '?':  c = '?'; goto escape_letter;
-       case 'u':  base = 10; break;
-       case 'x':  base = 16; break;
-       case '0':  base = 8; break;
+       case '\\': c = '\\'; return c;
+       case 'a':  c = '\a'; return c;
+       case 'f':  c = '\f'; return c;
+       case 'n':  c = '\n'; return c;
+       case 'r':  c = '\r'; return c;
+       case 't':  c = '\t'; return c;
+       case 'v':  c = '\v'; return c;
+       case '\'': c = '\\'; return c;
+       case '"':  c = '"';  return c;
+       case '?':  c = '?';  return c;
+       case 'u':
+               /*
+                * FIXME: universal constants are not correctly handled
+                */
+               if (!isdigit(*++input->p))
+                       warn("incorrect digit for numerical character 
constant");
+               base = 10;
+               break;
+       case 'x':
+               if (!isxdigit(*++input->p))
+                       warn("\\x used with no following hex digits");
+               base = 16;
+               break;
+       case '0':
+               if (!strchr("01234567", *++input->p))
+                       warn("\\0 used with no following octal digits");
+               base = 8;
+               break;
        default:
                warn("unknown escape sequence");
                return ' ';
        }
        errno = 0;
-       c = strtoul(++input->p, &input->p, base);
+       c = strtoul(input->p, &input->p, base);
        if (errno || c > 255)
                warn("character constant out of range");
-       return c;
-
-escape_letter:
-       ++input->p;
+       --input->p;
        return c;
 }
 
@@ -435,7 +447,8 @@ character(void)
        if ((c = *++input->p) == '\\')
                c = escape();
        else
-               c = *input->p++;
+               c = *input->p;
+       ++input->p;
        if (*input->p != '\'')
                error("invalid character constant");
        else