https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71832
Bug ID: 71832
Summary: ICE on invalid C++11 code with incorrect decltype use
for non-type template parameter: Segmentation fault
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: su at cs dot ucdavis.edu
Target Milestone: ---
The following C++11 code causes an ICE when compiled with the current GCC trunk
on x86_64-linux-gnu in both 32-bit and 64-bit modes.
This is a regression from 6.1.x.
$ g++-trunk -v
Using built-in specs.
COLLECT_GCC=g++-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/usr/local/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 7.0.0 20160710 (experimental) [trunk revision 238196] (GCC)
$
$ g++-6.1 -c small.cpp
small.cpp:2:21: error: expected nested-name-specifier before ‘decltype’
template < typename decltype (0) > struct A
^~~~~~~~
small.cpp:2:21: error: two or more data types in declaration of ‘parameter’
$
$ g++-trunk -c small.cpp
small.cpp:2:21: error: expected nested-name-specifier before ‘decltype’
template < typename decltype (0) > struct A
^~~~~~~~
small.cpp:2:21: error: two or more data types in declaration of ‘parameter’
small.cpp: In substitution of ‘template<<declaration error> > template<class
... S> void A<<declaration error> >::baz() [with S = <missing>; <declaration
error> = {}]’:
small.cpp:4:22: required from here
small.cpp:4:22: internal compiler error: Segmentation fault
void foo () { baz (); }
^
0xdbae6f crash_signal
../../gcc-source-trunk/gcc/toplev.c:335
0x73d863 tree_class_check
../../gcc-source-trunk/gcc/tree.h:3152
0x73d863 pop_nested_class()
../../gcc-source-trunk/gcc/cp/class.c:7785
0x702980 instantiate_template_1
../../gcc-source-trunk/gcc/cp/pt.c:17485
0x702980 instantiate_template(tree_node*, tree_node*, int)
../../gcc-source-trunk/gcc/cp/pt.c:17534
0x71439c fn_type_unification(tree_node*, tree_node*, tree_node*, tree_node*
const*, unsigned int, tree_node*, unification_kind_t, int, bool, bool)
../../gcc-source-trunk/gcc/cp/pt.c:17909
0x6746fb add_template_candidate_real
../../gcc-source-trunk/gcc/cp/call.c:3113
0x67542c add_template_candidate
../../gcc-source-trunk/gcc/cp/call.c:3191
0x67542c add_candidates
../../gcc-source-trunk/gcc/cp/call.c:5363
0x675cc6 build_new_method_call_1
../../gcc-source-trunk/gcc/cp/call.c:8391
0x675cc6 build_new_method_call(tree_node*, tree_node*, vec<tree_node*, va_gc,
vl_embed>**, tree_node*, int, tree_node**, int)
../../gcc-source-trunk/gcc/cp/call.c:8590
0x791ef3 cp_parser_postfix_expression
../../gcc-source-trunk/gcc/cp/parser.c:6880
0x79a68c cp_parser_unary_expression
../../gcc-source-trunk/gcc/cp/parser.c:7991
0x79aee7 cp_parser_cast_expression
../../gcc-source-trunk/gcc/cp/parser.c:8668
0x79b4e5 cp_parser_binary_expression
../../gcc-source-trunk/gcc/cp/parser.c:8770
0x79bdd0 cp_parser_assignment_expression
../../gcc-source-trunk/gcc/cp/parser.c:9058
0x79e6c9 cp_parser_expression
../../gcc-source-trunk/gcc/cp/parser.c:9225
0x79ee3f cp_parser_expression_statement
../../gcc-source-trunk/gcc/cp/parser.c:10686
0x78cc7b cp_parser_statement
../../gcc-source-trunk/gcc/cp/parser.c:10537
0x78d93c cp_parser_statement_seq_opt
../../gcc-source-trunk/gcc/cp/parser.c:10809
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.
$
----------------------------------------------------
// should be: template < decltype (0) > struct A
template < typename decltype (0) > struct A
{
void foo () { baz (); }
template < typename ... S > void baz () {};
};
