[Bug c++/70781] New: ICE on invalid C++ code with lambda expressions on x86_64-linux-gnu in finish_expr_stmt, at cp/semantics.c:677

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70781

            Bug ID: 70781
           Summary: ICE on invalid C++ code with lambda expressions on
                    x86_64-linux-gnu in finish_expr_stmt, at
                    cp/semantics.c:677
           Product: gcc
           Version: 6.0
            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 on
x86_64-linux-gnu in both 32-bit and 64-bit modes. 

It is a regression from 5.3.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 20160424 (experimental) [trunk revision 235394] (GCC) 
$ 
$ g++-5.3 -c small.cpp -std=c++11
small.cpp: In function ‘void foo()’:
small.cpp:5:5: error: expected primary-expression before ‘(’ token
   T ([=] (S) { [=] {}; }); 
     ^
small.cpp:5:11: error: ‘S’ has not been declared
   T ([=] (S) { [=] {}; }); 
           ^
$ g++-trunk -c small.cpp -std=c++11 
small.cpp: In lambda function:
small.cpp:5:22: internal compiler error: in finish_expr_stmt, at
cp/semantics.c:677
   T ([=] (S) { [=] {}; });
                      ^
0x7b4c50 finish_expr_stmt(tree_node*)
        ../../gcc-source-trunk/gcc/cp/semantics.c:677
0x745722 cp_parser_expression_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:10720
0x73343b cp_parser_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:10534
0x7340ec cp_parser_statement_seq_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:10806
0x734bde cp_parser_lambda_body
        ../../gcc-source-trunk/gcc/cp/parser.c:10272
0x734bde cp_parser_lambda_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9756
0x735d8c cp_parser_primary_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:4933
0x737e16 cp_parser_postfix_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:6690
0x740f3c cp_parser_unary_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:7988
0x741797 cp_parser_cast_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:8665
0x741d95 cp_parser_binary_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:8767
0x742680 cp_parser_assignment_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9055
0x7441c6 cp_parser_parenthesized_expression_list
        ../../gcc-source-trunk/gcc/cp/parser.c:7459
0x744c31 cp_parser_functional_cast
        ../../gcc-source-trunk/gcc/cp/parser.c:25943
0x737d0a cp_parser_postfix_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:6615
0x740f3c cp_parser_unary_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:7988
0x741797 cp_parser_cast_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:8665
0x741d95 cp_parser_binary_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:8767
0x742680 cp_parser_assignment_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9055
0x744f59 cp_parser_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9222
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.
$ 


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


template < typename T >  
// OK: template < typename T, typename S > 
void foo ()
{
  T ([=] (S) { [=] {}; }); 
}