“this” captured by lambda is incorrect. GCC compiler bug?

Question

For the last few days, I have been debugging a weird issue involving lambdas in C++. I have reduced the problem down to the following symptoms:

• The

Answer 1

This seems to be a compiler bug in gcc 6.2, see:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77686

Workarounds:

• Use -fno-schedule-insns2 flag (as pointed out by gbmhunter, see comment below).
• Do not use -O2 optimizations or higher.

Answer 2

Sounds like the following compiler bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77933 (which only effects code generated with O1 optimizations or higher).