Question

I am having a weird error when calling the insert function on a vector of custom types (which are basically graph nodes). Following is the code that is generating the seg fault:

69     for (int i = 0; i < size; i++) {
70         PDTNode * node = arguments[i]->getNode();
71         //addChild(node);
72         children.insert(it, node); // children is vector <PDTNode*> 
73         it++;
74         node->addParent(this);
75     }

I double check all inputs and everything is OK and is not NULL. Below is the gdb stack trace that I got for the seg fault:

#0  0x00007ffff4793202 in ?? () from /lib/libc.so.6
#1  0x00007ffff479163a in memmove () from /lib/libc.so.6
#2  0x00000000004289f1 in std::__copy_move<false, true, std::random_access_iterator_tag>::__copy_m<PDTNode*> (__first=0x100bd60, __last=0x10053c8, 
__result=0x1001840) at /usr/include/c++/4.4/bits/stl_algobase.h:378
#3  0x00000000004289ab in std::__copy_move_a<false, PDTNode**, PDTNode**> (__first=0x100bd60, __last=0x10053c8, __result=0x1001840)
    at /usr/include/c++/4.4/bits/stl_algobase.h:397
#4  0x0000000000428973 in std::__copy_move_a2<false, PDTNode**, PDTNode**>     (__first=0x100bd60, __last=0x10053c8, __result=0x1001840)
    at /usr/include/c++/4.4/bits/stl_algobase.h:436
#5  0x000000000042891d in std::copy<PDTNode**, PDTNode**> (__first=0x100bd60, __last=0x10053c8, __result=0x1001840)
at /usr/include/c++/4.4/bits/stl_algobase.h:468
#6  0x00000000004288dc in std::__uninitialized_copy<true>::uninitialized_copy<PDTNode**, PDTNode**> (__first=0x100bd60, __last=0x10053c8, __result=0x1001840)
    at /usr/include/c++/4.4/bits/stl_uninitialized.h:93
#7  0x0000000000428847 in std::uninitialized_copy<PDTNode**, PDTNode**> (__first=0x100bd60, __last=0x10053c8, __result=0x1001840)
    at /usr/include/c++/4.4/bits/stl_uninitialized.h:117
#8  0x00000000004287b8 in std::__uninitialized_copy_a<PDTNode**, PDTNode**, PDTNode*> (__first=0x100bd60, __last=0x10053c8, __result=0x1001840)
    at /usr/include/c++/4.4/bits/stl_uninitialized.h:257
#9  0x0000000000428684 in std::__uninitialized_move_a<PDTNode**, PDTNode**, std::allocator<PDTNode*> > (__first=0x100bd60, __last=0x10053c8, 
    __result=0x1001840, __alloc=...) at /usr/include/c++/4.4/bits/stl_uninitialized.h:267
#10 0x000000000042812e in std::vector<PDTNode*, std::allocator<PDTNode*> >::_M_insert_aux (this=0x1002810, __position=..., __x=@0x7fffffffd538)
    at /usr/include/c++/4.4/bits/vector.tcc:338
#11 0x000000000043c46d in std::vector<PDTNode*, std::allocator<PDTNode*> >::insert (this=0x1002810, __position=..., __x=@0x7fffffffd538)
    at /usr/include/c++/4.4/bits/vector.tcc:126
#12 0x00000000004d3ea9 in PDTFunctionDec::setArguments (this=0x10027e0, arguments=...) at PDTFunction.cpp:72

Any help is highly appreciated.

Thank you

Answer 1

I guess it is an iterator, but by inserting an element you trigger a relocation of the elements in the container and therefore invalidate the iterator. That should be the cause of your segmentation fault.