https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97537
--- Comment #2 from Jonathan Wakely ---
Oh sorry, I misread your example. The second #include "header3.h" is indeed
reached. The header is skipped due to the optimization described at
https://gcc.gnu.org/onlinedocs/cpp/Once-Only-Headers.html so t
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97537
--- Comment #1 from Jonathan Wakely ---
But the compiler never sees that #include, because it's guarded by the #ifndef
The -H option is not a general purpose dependency scanner, it just shows the
result of preprocessing. The documentation is cle
