Stop the compiler from destroying the source code

[fredrikr]

If you specify the name of the source code file twice on the commandline, the source code is overwritten with the compiled file, like:

inform6 +library mygame.inf -v5 -e -s -z mygame.inf

This is pretty nasty.

[erkyrath]

That seems like a special case which command-line tools generally do not worry about.

cc -o test.c test.c

This destroys test.c.

It could only be fixed in a narrow sense, anyhow. We could try to compare the filenames, but that wouldn't catch inform test.inf ./test.inf or inform test.inf TEST.INF. Not to mention overwriting library files or other files.

[fredrikr]

Maybe refuse to write to files ending with .inf? That's the major risk here.

[heasm66]

A simple check that output file is not *.inf, *.c or *.h?

inform.c

@@ -1916,6 +1916,19 @@ static int sub_main(int argc, char **argv)

    read_command_line(argc, argv);

    int32 len = strlen(cli_file2);
    char s[4];
    int32 i;
    for (i = 0; i < 4; i++)
        s[i] = cli_file2[len - 4 + i];
    make_lower_case(s);
    if ((s[0] == '.' && s[1] == 'i' && s[2] == 'n' && s[3] == 'f') ||
        (s[2] == '.' && s[3] == 'c') ||
        (s[2] == '.' && s[3] == 'h')) {
        printf("\n[No compilation completed. Output file extension can't be '*.inf', '*.c' or '*.h'.]\n");
        return(0);
    }

    if (cli_files_specified > 0)
    {   return_code = compile(cli_files_specified, cli_file1, cli_file2);

[erkyrath]

I still think this is a bad idea. Even aside from the question of deciding which suffixes to watch for. (They're configured in header.h, not necessarily ".inf" even though we assume that these days. And nothing about the compiler requires you to use ".inf" and ".h" extensions on your files.)

There's a lot of mistakes you can make on the command line. Fixes like this will not prevent all of them and will prevent some things that are currently legal. It seems like a misconceived idea and I think it should be closed.

[heasm66]

I tend to agree.

[fredrikr]

Sure, it will prevent some things that are currently legal. Like:

inform +lib mygame.inf mygame.inf

(This currently builds a z5 game called mygame.inf, overwriting the source code)

And while it wouldn't remove all risks, it would remove some risk.

But I don't expect to get get all my suggestions implemented. If you think it's a bad idea, that's fine with me.