https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68087
Bug ID: 68087
Summary: ICE with constexpr in array with negative index
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: roger.ferrer at bsc dot es
Target Milestone: ---
Hi,
GCC 6.0.0 20151025 and 5.2 crash with an ICE with the following code:
-- ice.cc
constexpr char c[] = "hello";
constexpr const char *p = c;
void f()
{
static_assert(*(p-1) == 'h', "");
}
-- end of ice.cc
$ g++ --version
g++ (GCC) 6.0.0 20151025 (experimental)
$ g++ -std=c++11 -c ice.cc
ice.cc: In function ‘void f()’:
ice.cc:6:37: internal compiler error: in tree_to_shwi, at tree.c:7304
static_assert(*(p-1) == 'h', "");
^
0xf2fec2 tree_to_shwi(tree_node const*)
../../gcc-git/gcc/tree.c:7304
0x7fc084 cxx_eval_array_reference
../../gcc-git/gcc/cp/constexpr.c:1785
0x7fc084 cxx_eval_constant_expression
../../gcc-git/gcc/cp/constexpr.c:3485
0x7fb18c cxx_eval_indirect_ref
../../gcc-git/gcc/cp/constexpr.c:2588
0x7fb18c cxx_eval_constant_expression
../../gcc-git/gcc/cp/constexpr.c:3340
0x7fe63e cxx_eval_binary_expression
../../gcc-git/gcc/cp/constexpr.c:1601
0x7fa994 cxx_eval_constant_expression
../../gcc-git/gcc/cp/constexpr.c:3462
0x7fff0b cxx_eval_outermost_constant_expr
../../gcc-git/gcc/cp/constexpr.c:3746
0x801980 maybe_constant_value(tree_node*, tree_node*)
../../gcc-git/gcc/cp/constexpr.c:3859
0x772f15 finish_static_assert(tree_node*, tree_node*, unsigned int, bool)
../../gcc-git/gcc/cp/semantics.c:8291
0x6f47a2 cp_parser_static_assert
../../gcc-git/gcc/cp/parser.c:12662
0x70b099 cp_parser_block_declaration
../../gcc-git/gcc/cp/parser.c:11880
0x70bed1 cp_parser_declaration_statement
../../gcc-git/gcc/cp/parser.c:11496
0x70804a cp_parser_statement
../../gcc-git/gcc/cp/parser.c:10162
0x708971 cp_parser_statement_seq_opt
../../gcc-git/gcc/cp/parser.c:10440
0x708a73 cp_parser_compound_statement
../../gcc-git/gcc/cp/parser.c:10394
0x708c00 cp_parser_function_body
../../gcc-git/gcc/cp/parser.c:20216
0x708c00 cp_parser_ctor_initializer_opt_and_function_body
../../gcc-git/gcc/cp/parser.c:20252
0x709929 cp_parser_function_definition_after_declarator
../../gcc-git/gcc/cp/parser.c:24856
0x70a82b cp_parser_function_definition_from_specifiers_and_declarator
../../gcc-git/gcc/cp/parser.c:24768
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
GCC 5.1 and earlier emit a diagnostic instead:
$ g++-5.1 -std=c++11 -c ice.cc
ice.cc: In function ‘void f()’:
ice.cc:6:5: error: non-constant condition for static assertion
static_assert(*(p-1) == 'h', "");
^
ice.cc:6:5: error: array subscript out of bound
Kind regards,
