https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68819
--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> --- (In reply to David Malcolm from comment #1) > Is it a file with many includes? libcpp can go into a fallback mode where > it stops supplying column numbers, when location_t goes >= > LINE_MAP_MAX_LOCATION_WITH_COLS. That seems to be the case - at least, I am down to: #include "some.h" // Unrelated, but includes boost and some other headers #include "four.h" where four.h contains '#include "three.h"' etc. until two.h, which contains the header file with the class which has unsigned int get_max_index() const { if (ul) return 4; return 0; } The compilation takes about 10s - thus, I assume g++ has quite something to read & process. I am going to reduce the last-mentioned header file & might try to mimic "some.h" by creating some nested header files - but I fear the latter is a bit pointless, if I have to add that many locations that one runs out of LINE_MAP_MAX_LOCATION_WITH_COLS. [Off topic: PR66298 shows a case, were indentation is missing and -Wmisleading-indentation does not warn.]