Newbie GDC issues

[H. S. Teoh]

On Fri, Sep 06, 2013 at 02:59:30AM +0200, Ramon wrote:
> On Thursday, 5 September 2013 at 23:58:06 UTC, H. S. Teoh wrote:
> 
> Thanks and
> 
> >@Iain: on that note, it looks like gdb thinks it's debugging C++, but
> >D doesn't have anything called 'operator[]'. It would be Really Nice
> >if we could somehow coax gdb to use opIndex instead (though it
> >doesn't really help in the case of dyn arrays 'cos they are built-in,
> >and don't actually have any opIndex to speak of).
> 
> I'm not so sure.
> 
> Observation:
> 
> >print someDynArray.length
> 10                               // works
> 
> char[5] cArray = "Hello";        // Let's try C like fixed length
> array
> 
> >print cArray[3]
> 'l'                              // works
> 
> I'm not that sure dyn arrays have no [] (or index or whatever it's
> called) operator. In the end they are just arrays with smart
> housekeeping behind the curtains and some methods (like "length").
[...]

Actually, D arrays are implemented something like this:

	/* C code equivalent */
	struct int_array {
		int *ptr;
		size_t length;
	}

So if you do something like 'print someDynArray.ptr[4]' it should work.

Now obviously gdb does support more abstract array-like types, like C++
types that define operator[], so I was just saying that it would be nice
if we could figure out what to put in the debug data segment to make gdb
translate arr[i] in D into arr.ptr[i].

Static arrays in D are closer to C's stack-allocated arrays (e.g. if you
declare 'char localVar[10];' inside a function), so they more-or-less
work seamlessly with C array indexing notation.


T

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