[Bug c++/84160] New: ICE on valid C++11 code: in build_capture_proxy, at cp/lambda.c:446

["su at cs dot ucdavis.edu" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84160

            Bug ID: 84160
           Summary: ICE on valid C++11 code: in build_capture_proxy, at
                    cp/lambda.c:446
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

This seems to be a recent regression. 

$ g++tk -v
Using built-in specs.
COLLECT_GCC=g++tk
COLLECT_LTO_WRAPPER=/home/su/software/tmp/gcc/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/8.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/home/su/software/tmp/gcc/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 8.0.1 20180131 (experimental) [trunk revision 257233] (GCC) 
$ 
$ g++-7.2.0 -c tmp.cpp
$ 
$ g++tk -c tmp.cpp
tmp.cpp: In instantiation of ‘void f(T ...) [with T = {int}]’:
tmp.cpp:8:15:   required from here
tmp.cpp:3:13: internal compiler error: in build_capture_proxy, at
cp/lambda.c:446
   [a ...] { [a ...] {}; };
             ^
0x7b01b4 build_capture_proxy(tree_node*, tree_node*)
        ../../gcc-source-trunk/gcc/cp/lambda.c:446
0x7b4472 start_lambda_function(tree_node*, tree_node*)
        ../../gcc-source-trunk/gcc/cp/lambda.c:1360
0x89c838 tsubst_lambda_expr(tree_node*, tree_node*, int, tree_node*)
        ../../gcc-source-trunk/gcc/cp/pt.c:17018
0x861541 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:18312
0x8540cf tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16804
0x855e95 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16025
0x85391b tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16011
0x854af8 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16288
0x85391b tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16011
0x854af8 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16288
0x89c876 tsubst_lambda_expr(tree_node*, tree_node*, int, tree_node*)
        ../../gcc-source-trunk/gcc/cp/pt.c:17023
0x861541 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:18312
0x8540cf tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16804
0x855e95 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16025
0x85391b tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16011
0x854af8 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:16288
0x851cb1 instantiate_decl(tree_node*, bool, bool)
        ../../gcc-source-trunk/gcc/cp/pt.c:23352
0x8a2232 instantiate_pending_templates(int)
        ../../gcc-source-trunk/gcc/cp/pt.c:23468
0x781d62 c_parse_final_cleanups()
        ../../gcc-source-trunk/gcc/cp/decl2.c:4715
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
$ 


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template < typename ... T > void f (T ... a) 
{
  [a ...] { [a ...] {}; };
}

void g ()
{
  f < int > (0);
}