https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84036
Bug ID: 84036 Summary: [8 Regression] ICE on valid code in C++14, variadic lambda capture in a template function Product: gcc Version: 8.0.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: benni.buch at gmail dot com Target Milestone: --- Older versions of g++ compile this successfully, g++-8 fails with an ICE: template < typename T > auto f(T){ [](auto ... i){ [i ...]{}; }; } int main(){ f(0); } $ g++ --version g++ (GCC) 8.0.1 20180124 (experimental) Copyright (C) 2018 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. $ g++ -std=c++14 main.cpp main.cpp: In instantiation of 'auto f(T) [with T = int]': main.cpp:9:8: required from here main.cpp:4:9: internal compiler error: in build_capture_proxy, at cp/lambda.c:446 [i ...]{}; ^ 0x8a0975 build_capture_proxy(tree_node*, tree_node*) ../../gcc/gcc/cp/lambda.c:446 0x8a36d6 start_lambda_function(tree_node*, tree_node*) ../../gcc/gcc/cp/lambda.c:1360 0x924750 tsubst_lambda_expr(tree_node*, tree_node*, int, tree_node*) ../../gcc/gcc/cp/pt.c:17005 0x926098 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool) ../../gcc/gcc/cp/pt.c:18299 0x9339f9 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool) ../../gcc/gcc/cp/pt.c:17053 0x9339f9 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:16791 0x932530 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:16012 0x931351 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:15998 0x930b41 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:16275 0x930b41 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:16275 0x92479b tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:15983 0x92479b tsubst_lambda_expr(tree_node*, tree_node*, int, tree_node*) ../../gcc/gcc/cp/pt.c:17009 0x926098 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool) ../../gcc/gcc/cp/pt.c:18299 0x9339f9 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool) ../../gcc/gcc/cp/pt.c:17053 0x9339f9 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:16791 0x932530 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:16012 0x931351 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:15998 0x930b41 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:16275 0x92fdd8 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool) ../../gcc/gcc/cp/pt.c:15983 0x92fdd8 instantiate_decl(tree_node*, bool, bool) ../../gcc/gcc/cp/pt.c:23337 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. Known to work with: $ g++-5 --version g++-5 (Ubuntu 5.4.1-2ubuntu1~16.04) 5.4.1 20160904 Copyright (C) 2015 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. $ g++-6 --version g++-6 (Ubuntu/Linaro 6.3.0-18ubuntu2~16.04) 6.3.0 20170519 Copyright (C) 2016 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.