[Bug c++/69638] array out of bounds access accepted in constexpr function invocation

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69638

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |egallager at gcc dot gnu.org

--- Comment #1 from Eric Gallager <egallager at gcc dot gnu.org> ---
I get the following errors with gcc8:

$ /usr/local/bin/g++ -c -S -Wall -Wextra -Wpedantic -std=c++14 -xc++ 69638.cc
69638.cc:11:28:   in constexpr expansion of ‘foo()’
69638.cc:11:33: error: array subscript value ‘99’ is outside the bounds of
array ‘a’ of type ‘A [3]’
 struct B { unsigned b: foo () + 1; };
                                 ^
69638.cc:7:4: note: declared here
  A a [3] = { 1, 2, 3 };
    ^
69638.cc:11:33: error: bit-field ‘B::b’ width not an integer constant
 struct B { unsigned b: foo () + 1; };
                                 ^
69638.cc: In function ‘constexpr int bar(int)’:
69638.cc:16:8: warning: ISO C++ forbids variable length array ‘a’ [-Wvla]
  A a [n] = { 1, 2, 3 };
        ^
69638.cc: At global scope:
69638.cc:21:21:   in constexpr expansion of ‘bar(1)’
69638.cc:21:27: error: array subscript value ‘1’ is outside the bounds of array
‘a’ of type ‘A [n]’
     unsigned c: bar (1) + 1;
                           ^
69638.cc:16:4: note: declared here
  A a [n] = { 1, 2, 3 };
    ^
69638.cc:21:27: error: bit-field ‘C::c’ width not an integer constant
     unsigned c: bar (1) + 1;
                           ^
$

Were these the errors you were expecting? Leaving UNCONFIRMED because I'm not
sure...