On Fri, 6 Mar 2020 at 12:52, yilu@xxxxxxxxxxx wrote: > > Oh...I'm so sorry. I've read these guides but I miss that I should go into the objdir to configure. Thanks! > This time I got into the objdir and use: > `./../gcc/configure --prefix=/usr/local/gcc --enable-languages=all --disable-multilib --disable-bootstrap` > and I found the Makefile in my objdir directory. I try `make -j4` and found > g++: error: gengtype-lex.c: No such file or directory > g++: fatal error: no input files > Could you help me with this? See https://gcc.gnu.org/install/prerequisites.html Flex version 2.5.4 (or later) Necessary when modifying *.l files. Necessary to build GCC during development because the generated output files are not included in the version-controlled source repository. They are included in releases.