Re: [Tinycc-devel] Basic patch for passing W9X short DOS paths to TCC.

[Charlie Gordon]

----- Original Message ----- 
From: "lostgallifreyan" <address@hidden>
To: <address@hidden>
Sent: Sunday, April 12, 2009 5:02 PM
Subject: [Tinycc-devel] Basic patch for passing W9X short DOS paths to TCC.

> As promised, here's a basic patch for allowing files passed to TCC to work 
> in W9X.
> It can be easily overridden for usual case sensitive file extension
> handling, but in Windows it's up to the user to see that the file
> pointed to contains the right stuff, especially in instances of ASM
> coding where .s and .S are important. You can't specify which in the
> file name, but you can still do it in the written path, even with this 
> patch.
>
> Immediately below this line in tcc.c:
>            /* add a new file */
> I added this:
> #ifdef _WIN32
>            /* Set W9X DOS 8.3 upper case paths to lower case. */
>            char *p;
>            if (r[1] == ':' && r[2] == '\\') {
>                for (p = r; *p; p++) {
>                    if (*p != toupper(*p))
>                        break;
>                    else
>                        for (p = r; *p; p++)
>                            *p = tolower(*p);
>                }
>            }
> #endif
>
> I considered a command line switch as suggested by a couple of
> people in the earlier thread, but I think this is neater, it only
> operates in very limited circumstances. If you want to be sure it does
> nothing, make a forward slash instead of that first backslash, or a
> lower case letter on the path, any of these will stop it acting, it
> ONLY does something if it looks like a standard all caps path, so be
> aware that if you like all-caps long-name paths you need to think
> about that if you try this patch...
>
> My test for the colon and backslash in Windows paths might even be
> redundant given the #ifdef_WIN32 bit, but I'm playing it safe in case
> Windows Mobile is considered as Win32, because it doesn't use a single
> drive letter at the start of a path. That backslash test is a useful
> tool, it allows the change to a forward slash to disable the patch as
> a command line switch might do.

I don't think this is going in the right direction:
- Command line arguments should not be changed
- Why restrict this behaviour to full paths with a drive letter ?
- instead of matching filename extensions in a case independent manner ?

Also more importantly, do not pass char arguments to tolower/toupper and
islower/isupper functions.  'char' may be signed whereas these functions 
expect
an int parameter with a value among those of type unsigned char or EOF.
The argument to these functions should at least be cast to (unsigned char),
and so should the value you compare their result to.

>                    if (*p != toupper(*p))

if ((unsigned char)*p != toupper((unsigned char)*p)

>                            *p = tolower(*p);

*p = tolower((unsigned char)*p);

If you don't like the resulting code (quite ugly in my opinion),
you should use a temporary variable:

int c = (unsigned char)*p;
if (toupper(c) != c) ...

*p = tolower(c);

But all things considered, I still argue that the correct approach to the 
problem
you are trying to fix, is to perform case insensitive matching on filename 
extensions
wherever these occur.  A simple way to do this is to identify all 
occurrences of such
matching and use call function with a platform dependent implementation.

--
Chqrlie.