https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70556
Bug ID: 70556
Summary: ICE in cxx_eval_vec_init_1 on a ill-formed lambda
capture of a VLA in a template
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
The following ill-formed snippet causes an ICE with today's trunk of GCC 6.0
and all prior versions. In case someone wonders, I ran into it by accident (by
making a typo while writing a test case for a different bug), not by
deliberately trying to break things.
$ cat t.c && /build/gcc-trunk/gcc/xgcc -B /build/gcc-trunk/gcc -S -Wall -Wextra
-Wpedantic -xc++ t.c
template <int N>
int f (int n)
{
int x[1][n];
return [x[0]] /* () { return 0; } */;
}
int i = f<1>(1);
t.c: In function ‘int f(int)’:
t.c:6:12: error: expected ‘,’ before ‘[’ token
return [x[0]] /* () { return 0; } */;
^
t.c:6:12: error: expected identifier before ‘[’ token
t.c: In lambda function:
t.c:6:39: error: expected ‘{’ before ‘;’ token
return [x[0]] /* () { return 0; } */;
^
t.c: In instantiation of ‘int f(int) [with int N = 1]’:
t.c:9:15: required from here
t.c:4:7: warning: ISO C++ forbids variable length array [-Wvla]
int x[1][n];
^
t.c:6:10: internal compiler error: in tree_to_uhwi, at tree.c:7345
return [x[0]] /* () { return 0; } */;
^
0x11504c5b tree_to_uhwi(tree_node const*)
/src/gcc/trunk/gcc/tree.c:7345
0x106f2157 cxx_eval_vec_init_1
/src/gcc/trunk/gcc/cp/constexpr.c:2469
0x106f242f cxx_eval_vec_init_1
/src/gcc/trunk/gcc/cp/constexpr.c:2521
0x106f29d3 cxx_eval_vec_init
/src/gcc/trunk/gcc/cp/constexpr.c:2591
0x106f8ffb cxx_eval_constant_expression
/src/gcc/trunk/gcc/cp/constexpr.c:3872
0x106fa4af cxx_eval_outermost_constant_expr
/src/gcc/trunk/gcc/cp/constexpr.c:4110
0x106fb2cb maybe_constant_value_1
/src/gcc/trunk/gcc/cp/constexpr.c:4298
0x106fb487 maybe_constant_value(tree_node*, tree_node*)
/src/gcc/trunk/gcc/cp/constexpr.c:4322
0x106fb9f3 fold_non_dependent_expr(tree_node*)
/src/gcc/trunk/gcc/cp/constexpr.c:4401
0x1046d70b massage_init_elt
/src/gcc/trunk/gcc/cp/typeck2.c:1229
0x1046e6f7 process_init_constructor_record
/src/gcc/trunk/gcc/cp/typeck2.c:1401
0x1046f66f process_init_constructor
/src/gcc/trunk/gcc/cp/typeck2.c:1609
0x1046cdab digest_init_r
/src/gcc/trunk/gcc/cp/typeck2.c:1123
0x1046d04b digest_init(tree_node*, tree_node*, int)
/src/gcc/trunk/gcc/cp/typeck2.c:1162
0x10601473 finish_compound_literal(tree_node*, tree_node*, int)
/src/gcc/trunk/gcc/cp/semantics.c:2732
0x106d7307 build_lambda_object(tree_node*)
/src/gcc/trunk/gcc/cp/lambda.c:114
0x104346ef tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
/src/gcc/trunk/gcc/cp/pt.c:17123
0x1042c083 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
/src/gcc/trunk/gcc/cp/pt.c:15802
0x10425f4b tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
/src/gcc/trunk/gcc/cp/pt.c:15114
0x10425e73 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
/src/gcc/trunk/gcc/cp/pt.c:15104
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.
