https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68968
--- Comment #3 from kargl at gcc dot gnu.org --- (In reply to kargl from comment #2) > (In reply to kargl from comment #1) > > (In reply to Fred Krogh from comment #0) > > > Created attachment 37073 [details] > > > Compile this as indicated in the comments and get a segmentation fault in > > > the compiler > > > > > > test.F90 attached gives an internal compiler error (Segmentation fault) > > > when > > > compiled with > > > > > > gfortran -Dplet_=\'q\' -o test test.F90 > > > > > > If gfortran is replaced by cpp in the above, it seems to generate what one > > > would expect. > > > > A workaround is to remove the apostrophes around 's', 'd', and 'q'. > > Forgot to add > > % gfc6 -E -Dplet_=s ~/tmp/wq.F90 | cat -s > # 1 "/mnt/sgk/tmp/wq.F90" > # 1 "<built-in>" > # 1 "<command-line>" > # 1 "/mnt/sgk/tmp/wq.F90" > program test > > print '(A)', "C_FLOAT" > stop > end program test Crudge I should know better than to try to help with gfortran's cpp feature. Forget I mentioned the above.