https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83058
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org,
| |msebor at gcc dot gnu.org
Target Milestone|8.0 |6.5
Summary|[8 Regression] ICE on C++ |[6/7/8 Regression] ICE on
|code with negative array |C++ code with negative
|index: in |array index: in
|warn_placement_new_too_smal |warn_placement_new_too_smal
|l, at cp/init.c:2666 |l, at cp/init.c:2666
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Not so recent regression, started with r229827.
There are multiple bugs in that code:
if (CONSTANT_CLASS_P (adj))
should really be a test for TREE_CODE (adj) == INTEGER_CST, tree_to_shwi is
going to ICE on anything else.
const_tree adj = TREE_OPERAND (oper, 1);
if (!use_obj_size && CONSTANT_CLASS_P (adj))
adjust += tree_to_shwi (adj);
similarly, plus there is no checking of addition overflows.
I think it might be better to turn adjust into an offset_int in which you
compute everything and then check if it can actually be used (or force
use_obj_size otherwise).
gcc_checking_assert (0 <= adjust);
this is where we ICE. The comparison operand order is incorrect too.
if (CONSTANT_CLASS_P (size))
Again, wrong check. Should be probably if (tree_fits_uhwi_p (size)).
bytes_need = tree_to_uhwi (size);
else if (nelts && CONSTANT_CLASS_P (nelts))
bytes_need = tree_to_uhwi (nelts)
* tree_to_uhwi (TYPE_SIZE_UNIT (type));
The above is also misformatted, should be
bytes_need = tree_to_uhwi (nelts)
* tree_to_uhwi (TYPE_SIZE_UNIT (type));
or
bytes_need = (tree_to_uhwi (nelts)
* tree_to_uhwi (TYPE_SIZE_UNIT (type)));
or
bytes_need
= tree_to_uhwi (nelts) * tree_to_uhwi (TYPE_SIZE_UNIT (type)));
What about the case when TYPE_SIZE_UNIT doesn't fit into uhwi? That will ICE
too.
else if (tree_fits_uhwi_p (TYPE_SIZE_UNIT (type)))
bytes_need = tree_to_uhwi (TYPE_SIZE_UNIT (type));
