Re: cpplib: patch: three long-standing bugs

[Dave Brolley <brolley at cygnus dot com>]

This patch is OK.

Dave

Zack Weinberg wrote:

> Dave Brolley wrote:
> > Other than the issue of what to do with NUL bytes in the source, I have only
> > one
> > question about this patch. Why not generate a message for each unterminated
> > conditional on the stack? This patch appears to generate a message for the
> > innermost one.
>
> Here is an updated patch which generates a message for each
> unterminated conditional.  It also contains a fix for the -traditional
> string handling, but not the NUL changes.
>
> zw
>
> 1999-09-09 22:42 -0700  Zack Weinberg  <zack@bitmover.com>
>
>         * cppalloc.c (xstrdup): Use memcpy.
>         * cpperror.c (cpp_print_containing_files): Don't use
>         cpp_notice.
>         * cpplib.c (conditional_skip): Set temp->lineno.
>         (do_endif): Make error message less obscure.
>         (if_directive_name): New function.
>         (cpp_get_token [case EOF]): Unwind the if stack and generate
>         error messages for each unterminated conditional in this file.
>         (parse_string):  Do not behave differently if -traditional.
>
> ===================================================================
> Index: cppalloc.c
> --- cppalloc.c  1999/09/07 05:47:40     1.16
> +++ cppalloc.c  1999/09/10 05:37:16
> @@ -74,8 +74,8 @@ char *
>  xstrdup (input)
>    const char *input;
>  {
> -  unsigned size = strlen (input);
> -  char *output = xmalloc (size + 1);
> -  strcpy (output, input);
> +  size_t size = strlen (input) + 1;
> +  char *output = xmalloc (size);
> +  memcpy (output, input, size);
>    return output;
>  }
> ===================================================================
> Index: cpperror.c
> --- cpperror.c  1999/09/07 15:41:24     1.17
> +++ cpperror.c  1999/09/10 05:37:16
> @@ -63,8 +63,8 @@ cpp_print_containing_files (pfile)
>           if (first)
>             {
>               first = 0;
> -             cpp_notice ("In file included from %s:%ld",
> -                         ip->nominal_fname, line);
> +             cpp_message (pfile, -1, "In file included from %s:%ld",
> +                          ip->nominal_fname, line);
>             }
>           else
>             cpp_message (pfile, -1, ",\n                 from %s:%ld",
> ===================================================================
> Index: cpplib.c
> --- cpplib.c    1999/09/09 04:00:36     1.92
> +++ cpplib.c    1999/09/10 05:37:17
> @@ -1944,9 +1944,7 @@ conditional_skip (pfile, skip, type, con
>
>    temp = (IF_STACK_FRAME *) xcalloc (1, sizeof (IF_STACK_FRAME));
>    temp->fname = CPP_BUFFER (pfile)->nominal_fname;
> -#if 0
>    temp->lineno = CPP_BUFFER (pfile)->lineno;
> -#endif
>    temp->next = pfile->if_stack;
>    temp->control_macro = control_macro;
>    pfile->if_stack = temp;
> @@ -2177,7 +2175,7 @@ do_endif (pfile, keyword)
>    skip_rest_of_line (pfile);
>
>    if (pfile->if_stack == CPP_BUFFER (pfile)->if_stack)
> -    cpp_error (pfile, "unbalanced `#endif'");
> +    cpp_error (pfile, "`#endif' not within a conditional");
>    else
>      {
>        IF_STACK_FRAME *temp = pfile->if_stack;
> @@ -2235,6 +2233,25 @@ validate_else (pfile, directive)
>                  "text following `%s' violates ANSI standard", directive);
>  }
>
> +/* Convert T_IF, etc. to a string.   Used in error messages.  */
> +static const char *
> +if_directive_name (pfile, ifs)
> +     cpp_reader *pfile;
> +     struct if_stack *ifs;
> +{
> +  switch (ifs->type)
> +    {
> +    case T_IF:     return "#if";
> +    case T_IFDEF:   return "#ifdef";
> +    case T_IFNDEF:  return "#ifndef";
> +    case T_ELIF:    return "#elif";
> +    case T_ELSE:    return "#else";
> +    default:
> +      cpp_fatal (pfile, "impossible if_stack->type value %d", ifs->type);
> +      return "unknown";
> +    }
> +}
> +
>  /* Get the next token, and add it to the text in pfile->token_buffer.
>     Return the kind of token we got.  */
>
> @@ -2265,9 +2282,23 @@ cpp_get_token (pfile)
>         }
>        else
>         {
> -         cpp_buffer *next_buf
> -           = CPP_PREV_BUFFER (CPP_BUFFER (pfile));
> -         CPP_BUFFER (pfile)->seen_eof = 1;
> +         cpp_buffer *next_buf = CPP_PREV_BUFFER (CPP_BUFFER (pfile));
> +         struct if_stack *ifs, *nifs;
> +
> +         /* Unwind the conditional stack and generate error messages.  */
> +         for (ifs = pfile->if_stack;
> +              ifs != CPP_BUFFER (pfile)->if_stack;
> +              ifs = nifs)
> +           {
> +             cpp_error_with_line (pfile, ifs->lineno, -1,
> +                                  "unterminated `%s' conditional",
> +                                  if_directive_name (pfile, ifs));
> +
> +             nifs = ifs->next;
> +             free (ifs);
> +           }
> +         pfile->if_stack = ifs;
> +
>           if (CPP_BUFFER (pfile)->nominal_fname
>               && next_buf != CPP_NULL_BUFFER (pfile))
>             {
> @@ -2280,6 +2311,8 @@ cpp_get_token (pfile)
>               output_line_command (pfile, leave_file);
>               CPP_BUFFER (pfile) = cur_buffer;
>             }
> +
> +         CPP_BUFFER (pfile)->seen_eof = 1;
>           return CPP_POP;
>         }
>      }
> @@ -2823,18 +2856,16 @@ parse_string (pfile, c)
>                  quote.  */
>               cpp_pop_buffer (pfile);
>               continue;
> -           }
> -         if (!CPP_TRADITIONAL (pfile))
> -           {
> -             cpp_error_with_line (pfile, start_line, start_column,
> -                                "unterminated string or character constant");
> -             if (pfile->multiline_string_line != start_line
> -                 && pfile->multiline_string_line != 0)
> -               cpp_error_with_line (pfile,
> -                                    pfile->multiline_string_line, -1,
> -                              "possible real start of unterminated constant");
> -             pfile->multiline_string_line = 0;
>             }
> +
> +         cpp_error_with_line (pfile, start_line, start_column,
> +                              "unterminated string or character constant");
> +         if (pfile->multiline_string_line != start_line
> +             && pfile->multiline_string_line != 0)
> +           cpp_error_with_line (pfile,
> +                                pfile->multiline_string_line, -1,
> +                        "possible real start of unterminated constant");
> +         pfile->multiline_string_line = 0;
>           break;
>         }
>        CPP_PUTC (pfile, cc);
> @@ -2843,11 +2874,9 @@ parse_string (pfile, c)
>         case '\n':
>           CPP_BUMP_LINE (pfile);
>           pfile->lineno++;
> -         /* Traditionally, end of line ends a string constant with
> -            no error.  */
> -         if (CPP_TRADITIONAL (pfile))
> -           return;
> -         /* Character constants may not extend over multiple lines.  */
> +         /* Character constants may not extend over multiple lines.
> +            In ANSI, neither may strings.  We accept multiline strings
> +            as an extension.  */
>           if (c == '\'')
>             {
>               cpp_error_with_line (pfile, start_line, start_column,