[Bug c++/71561] New: ICE with -Wall on valid C++ code on x86_64-linux-gnu: in potential_constant_expression_1, at cp/constexpr.c:5249

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71561

            Bug ID: 71561
           Summary: ICE with -Wall on valid C++ code on x86_64-linux-gnu:
                    in potential_constant_expression_1, at
                    cp/constexpr.c:5249
           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 code causes an ICE when compiled with the current GCC trunk with
-Wall on x86_64-linux-gnu in both 32-bit and 64-bit modes.  

It also seems to affect 5.x and later, and is a regression from 4.9.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 20160616 (experimental) [trunk revision 237533] (GCC)
$
$ g++-trunk -c small.cpp
$ g++-4.9 -c -Wall small.cpp
small.cpp: In function ‘void foo()’:
small.cpp:3:25: warning: statement has no effect [-Wunused-value]
   0 && ({ goto L1; 0; });
                         ^
$
$ g++-trunk -c -Wall small.cpp
small.cpp: In function ‘void foo()’:
small.cpp:3:24: internal compiler error: in potential_constant_expression_1, at
cp/constexpr.c:5249
   0 && ({ goto L1; 0; });
                        ^
0x8b1f27 potential_constant_expression_1
        ../../gcc-source-trunk/gcc/cp/constexpr.c:5249
0x8b1adf potential_constant_expression_1
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4854
0x8b2df3 potential_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:5269
0x8b2df3 potential_nondependent_constant_expression(tree_node*)
        ../../gcc-source-trunk/gcc/cp/constexpr.c:5311
0x8b3b92 maybe_constant_value_1
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4395
0x8b3b92 maybe_constant_value(tree_node*, tree_node*)
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4429
0x7d4252 cp_build_binary_op(unsigned int, tree_code, tree_node*, tree_node*,
int)
        ../../gcc-source-trunk/gcc/cp/typeck.c:5119
0x7e1853 ocp_convert(tree_node*, tree_node*, int, int, int)
        ../../gcc-source-trunk/gcc/cp/cvt.c:800
0x7e356c cp_convert
        ../../gcc-source-trunk/gcc/cp/cvt.c:616
0x7e356c cp_convert_and_check(tree_node*, tree_node*, int)
        ../../gcc-source-trunk/gcc/cp/cvt.c:635
0x7d3db3 cp_build_binary_op(unsigned int, tree_code, tree_node*, tree_node*,
int)
        ../../gcc-source-trunk/gcc/cp/typeck.c:5140
0x67bc1a build_new_op_1
        ../../gcc-source-trunk/gcc/cp/call.c:5849
0x67ccfe build_new_op(unsigned int, tree_code, int, tree_node*, tree_node*,
tree_node*, tree_node**, int)
        ../../gcc-source-trunk/gcc/cp/call.c:5894
0x7c0852 build_x_binary_op(unsigned int, tree_code, tree_node*, tree_code,
tree_node*, tree_code, tree_node**, int)
        ../../gcc-source-trunk/gcc/cp/typeck.c:3889
0x797ae6 cp_parser_binary_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:8921
0x798240 cp_parser_assignment_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9053
0x79ab39 cp_parser_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9220
0x79b15f cp_parser_expression_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:10681
0x7a9f9b cp_parser_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:10532
0x7aac5c cp_parser_statement_seq_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:10804
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.
$


--------------------------------


void foo ()
{ 
  0 && ({ goto L1; 0; });
 L1:;
}