🚀 go-pugleaf

dtrg@st-andrews.ac.uk (David Thomas Richard Given):
> I think I mentioned using alloca() on this newsgroup before, and received 
> quite a lot of mail telling me that it was nonstandard, nonportable, and 
> that use of it was generally heinous. :)
> 
> The problem is, it's so useful. There's a lot of cases when I write 
> programs when I allocate a variable-sized buffer at the beginning of a 

> function. If I use malloc(), I have to remember to free it at the end. 

Instead of this:

	int foo(int bar) {
		int *temp;

		temp = alloca(bar*sizeof(int));
		if (temp == NULL)
			return -1;
		... do funny things with temp and bar and whatever ...
		return 0;
	}

Do this:

	static int aux_foo(int bar, int *temp) {
		... do funny things with temp and bar and whatever ...
	}
	int foo(int bar) {
		int *temp;
		int ret;

		temp = malloc(bar*sizeof(int));
		if (temp == NULL)
			return -1;
		ret = aux_foo(bar, temp);
		free(temp);
		return ret;
	}

> My question is, is there a legal alloca() I can use anywhere? 

I don't think so.  See the FAQ, question 7.32.

> I'd really like to be able to use this function. Can I?

How portable do you wish to be?

-- 
Lars Wirzenius <liw@iki.fi> <wirzeniu@kruuna.helsinki.fi>
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