[lldb-dev] Printing non-truncated stdlib collections?

[Dun Peal]

In my case, it's a vector of vectors of pairs of ints, i.e.
vector<vector<pair<int,int>>>.

I'm not sure what "a sample of lldb taken while it's sitting there" means.
Sorry, I'm an LLVM newbie.

I have reproduced the problem with minimal code, posted below. Two
interesting observations:

1) For some reason, lldb prints each vector<pair<int,int>> as:

  [0] = size=4294967295 {
    [0] = (first = 0, second = 1)
    [1] = (first = 1, second = 2)
    [2] = (first = 2, second = 3)
    [3] = (first = 3, second = 4)
    ...
  }

Since each of those vectors is exactly 4 pairs, it is printed in its
entirety, so I'm not sure why there's an ellipsis there.

2) The times I quoted above are surprisingly preserved with this sample
code. For example, printing the first 256 elements is still about 8
seconds. Printing all 300 elements, which is only about 20% more, takes 300
seconds, i.e. almost x40 the time!  Curious.

#include <iostream>
#include <vector>

using namespace std;

int main() {
    vector<vector<pair<int,int> > > vec;
    for (int i=0; i < 300; ++i) {
        vector<pair<int,int> > v;
        for (int j=0; j < 4; ++j) {
            v.push_back(make_pair(i+j, i+j+1));
        }
        vec.push_back(v);
    }
    return 0;  // to reproduce, put a breakpoint in this line, and `p vec`
}


On Mon, Nov 4, 2013 at 12:49 PM, Enrico Granata <egranata at apple.com> wrote:

> Yes please. Possibly with a sample of lldb taken while it's sitting there.
> From your email, it sounds like the repro case is just a vector of pairs
> of int and int, with about 400 elements. Is that all?
>
> Sent from the iPhone of
> *Enrico Granata* <egranata@🍎.com>
>
> On Nov 4, 2013, at 12:42 PM, Dun Peal <dunpealer at gmail.com> wrote:
>
> Thanks!  This works, though surprisingly slow; I just printed a
> vector<vector<pair<int,int>>> of 384 elements, and it blocked for about 390
> seconds (6:30 minutes!) before rendering.
>
> The print only blocks for about 8 seconds when rendering the first 256
> elements (i.e. without the settings change).
>
> This is LLDB 3.4 from the LLVM aptitude repo, running on a high end
> Xubuntu Linux 13.04 developer workstation.
>
> This is obviously a major usability issue for me with LLDB. Should I file
> a bug for this?
>
>
> On Mon, Nov 4, 2013 at 10:05 AM, Greg Clayton <gclayton at apple.com> wrote:
>
>> (lldb) settings show target.max-children-count
>> target.max-children-count (int) = 256
>> (lldb) settings set target.max-children-count 10000
>>
>>
>> You can then add this line to your ~/.lldbinit file if you want the
>> setting to always be increased.
>>
>>
>> On Nov 3, 2013, at 7:57 PM, Dun Peal <dunpealer at gmail.com> wrote:
>>
>> > Hi,
>> >
>> > When I do:
>> >
>> > (lldb) p some_vector
>> >
>> > It seems LLDB only actually prints the first 256 values. How do I get
>> it to print the entire vector?
>> >
>> > Thanks, D.
>> > _______________________________________________
>> > lldb-dev mailing list
>> > lldb-dev at cs.uiuc.edu
>> > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>>
>>
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