[Bug c++/77522] New: ICE on invalid code C++14 code: in tsubst_decl, at cp/pt.c:12447

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77522

            Bug ID: 77522
           Summary: ICE on invalid code C++14 code: in tsubst_decl, at
                    cp/pt.c:12447
           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: ---

It affects 4.9.x and later, which have C++14 support. 


$ g++-trunk -c -std=c++14 small.cpp
small.cpp: In instantiation of ‘f(T)::<lambda()> [with T = int]’:
small.cpp:3:18:   required from ‘struct f(T) [with T = int]::<lambda()>’
small.cpp:3:8:   required from ‘void f(T) [with T = int]’
small.cpp:8:7:   required from here
small.cpp:3:24: error: use of ‘f(T) [with T = int]::<lambda()>::__a’ before
deduction of ‘auto’
   auto g = [&a = f] () {};
                        ^
small.cpp:3:24: error: use of ‘f(T) [with T = int]::<lambda()>::__a’ before
deduction of ‘auto’
small.cpp:3:24: internal compiler error: in tsubst_decl, at cp/pt.c:12447
0x6fe7c6 tsubst_decl
        ../../gcc-source-trunk/gcc/cp/pt.c:12447
0x6f32de tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../gcc-source-trunk/gcc/cp/pt.c:12907
0x6e07fa tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:15284
0x6dfa43 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:15419
0x6dd120 instantiate_decl(tree_node*, int, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:22159
0x7266b5 instantiate_class_template_1
        ../../gcc-source-trunk/gcc/cp/pt.c:10346
0x7266b5 instantiate_class_template(tree_node*)
        ../../gcc-source-trunk/gcc/cp/pt.c:10416
0x7cbf13 complete_type(tree_node*)
        ../../gcc-source-trunk/gcc/cp/typeck.c:133
0x6eaf2c tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:17269
0x6df247 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:15936
0x5df520 tsubst_init
        ../../gcc-source-trunk/gcc/cp/pt.c:13966
0x6e3144 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:15334
0x6dec3b tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:15228
0x6dfa43 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:15419
0x6dd120 instantiate_decl(tree_node*, int, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:22159
0x72a5f2 instantiate_pending_templates(int)
        ../../gcc-source-trunk/gcc/cp/pt.c:22278
0x76f597 c_parse_final_cleanups()
        ../../gcc-source-trunk/gcc/cp/decl2.c:4617
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 < class T = int > void f (T)
{ 
  auto g = [&a = f] () {};
}

int main ()
{ 
  f (0);
  return 0;
}