https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119548
Bug ID: 119548
Summary: ICE: tree check: accessed elt 2 of 'tree_vec' with 1
elts in tsubst_pack_expansion when accessing
uninstantiated decltype(lambda template return) type,
inside other lambda template
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: frederik.hofe at pm dot me
Target Milestone: ---
Created attachment 60926
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=60926&action=edit
minimum example code to trigger ICE
Example.cpp build with:
g++ -std=c++20 example.cpp
This issue is 100% reproducible and I even found a workaround for it. (See:
source code)
I tested with all "x86-64 gcc" on godbolt that support C++20, and the ICE is
triggered every time. This does not seem to be a regression.
godbolt.org results:
x86-64 gcc (trunk) (-std=c++20) <- internal compiler error: internal
compiler error: tree check: accessed elt 2 of 'tree_vec' with 1 elts in
tsubst_pack_expansion, at ...
x86-64 gcc 14.2 ... 10.1(-std=c++20) <- internal compiler error:
Segmentation fault
x86-64 clang 20.1.0 (-std=c++20) <- works fine
x64 msvc v19.40 BS17.10 (/std:c++20) <- works fine
