Debug Mode ENH 4/4: Add special iterator support

François Dumont frs.dumont@gmail.com
Tue May 8 13:15:00 GMT 2018 

Here is a patch to teach _Parameter type about special iterator types so 
that it improves final output.

It also get rid of the debug layer when possible so that failure output 
is cleaner. Debug mode is already transparent to users there is no need 
to show the Debug types in the output.

Here is the output for the newly added tests, for the move_iterator:

/home/fdt/dev/gcc/build/x86_64-pc-linux-gnu/libstdc++-v3/include/debug/vector:188:
In function:
     std::__debug::vector<_Tp, _Allocator>::vector(_InputIterator,
     _InputIterator, const _Allocator&) [with _InputIterator =
std::move_iterator<__gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<int*, 

     std::vector<int> >, std::__debug::vector<int> >; 
<template-parameter-2-2> = void; _Tp
     = int; _Allocator = std::allocator<int>]

Backtrace:
     ./debug_neg.exe() [0x402956]
     ./debug_neg.exe() [0x402db5]
     ./debug_neg.exe() [0x4011b9]
     /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0) 
[0x7f3962ef8830]
     ./debug_neg.exe() [0x401219]

Error: function requires a valid iterator range [__first, __last).

Objects involved in the operation:
     iterator "__first" @ 0x0x7ffc704c05f0 {
       type = std::move_iterator<__gnu_cxx::__normal_iterator<int*, 
std::vector<int, std::allocator<int> > > > (mutable iterator);
       state = dereferenceable;
       references sequence with type 'std::__debug::vector<int, 
std::allocator<int> >' @ 0x0x7ffc704c07a0
     }
     iterator "__last" @ 0x0x7ffc704c05f0 {
       type = std::move_iterator<__gnu_cxx::__normal_iterator<int*, 
std::vector<int, std::allocator<int> > > > (mutable iterator);
       state = dereferenceable (start-of-sequence);
       references sequence with type 'std::__debug::vector<int, 
std::allocator<int> >' @ 0x0x7ffc704c07a0
     }
XFAIL: 24_iterators/move_iterator/debug_neg.cc execution test

For the reverse_iterator:

/home/fdt/dev/gcc/build/x86_64-pc-linux-gnu/libstdc++-v3/include/debug/vector:188:
In function:
     std::__debug::vector<_Tp, _Allocator>::vector(_InputIterator,
     _InputIterator, const _Allocator&) [with _InputIterator =
std::reverse_iterator<__gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<int*, 

     std::vector<int> >, std::__debug::vector<int> >; 
<template-parameter-2-2> = void; _Tp
     = int; _Allocator = std::allocator<int>]

Backtrace:
     ./debug_neg.exe() [0x4020c1]
     ./debug_neg.exe() [0x400e59]
     /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0) 
[0x7f13fc56e830]
     ./debug_neg.exe() [0x400eb9]

Error: function requires a valid iterator range [__first, __last).

Objects involved in the operation:
     iterator "__first" @ 0x0x7ffc4e1f77d0 {
       type = std::reverse_iterator<__gnu_cxx::__normal_iterator<int*, 
std::vector<int, std::allocator<int> > > > (mutable iterator);
       state = past-the-reverse-end;
       references sequence with type 'std::__debug::vector<int, 
std::allocator<int> >' @ 0x0x7ffc4e1f7800
     }
     iterator "__last" @ 0x0x7ffc4e1f77d0 {
       type = std::reverse_iterator<__gnu_cxx::__normal_iterator<int*, 
std::vector<int, std::allocator<int> > > > (mutable iterator);
       state = dereferenceable (start-of-reverse-sequence);
       references sequence with type 'std::__debug::vector<int, 
std::allocator<int> >' @ 0x0x7ffc4e1f7800
     }
XFAIL: 24_iterators/reverse_iterator/debug_neg.cc execution test

Tested under Linux x8-_64.

I'll commit that tomorrow if not told otherwise.

     * include/debug/safe_iterator.h (_Safe_iterator<>::_M_constant()):
     Rename in...
     (_Safe_iterator<>::_S_constant()): ...that.
     * include/debug/safe_local_iterator.h
     (_Safe_local_iterator<>::_M_constant()): Rename in...
     (_Safe_local_iterator<>::_S_constant()): ...that.
     * include/debug/formatter.h: Remove bits/cpp_type_traits.h include.
     (_Iterator_state::__rbegin): New.
     (_Iterator_state::__rmiddle): New.
     (_Iterator_state::__rend): New.
     (_Parameter::_Parameter(const _Safe_iterator<>&, const char*,
     _Is_iterator)): Use _Safe_iterator<>::_S_constant. Grab normal 
underlying
     iterator type.
     (_Parameter::_Parameter(const _Safe_local_iterator<>&, const char*,
     _Is_iterator)): Likewise.
     (_Parameter::_S_reverse_state(_Iterator_state)): New.
         (_Parameter(__gnu_cxx::__normal_iterator<> const&, const char*,
     _Is_iterator)): New.
     (_Parameter(std::reverse_iterator<> const&, const char*,
     _Is_iterator)): New.
(_Parameter(std::reverse_iterator<_Safe_iterator<>> const&,
     const char*, _Is_iterator)): New.
     (_Parameter(std::move_iterator<> const&, const char*, _Is_iterator):
     New.
     (_Parameter(std::move_iterator<_Safe_iterator<>> const&, const char*,
     _Is_iterator)): New.
     * testsuite/24_iterators/move_iterator/debug_neg.cc: New.
     * testsuite/24_iterators/normal_iterator/debug_neg.cc: New.
     * testsuite/24_iterators/reverse_iterator/debug_neg.cc: New.

François

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