I am testing and playing a bit with flex before I start using it for a real project, but I am facing sone issues.
I am working on Android using a Linux emulator named Termux. I've installed flex and clang executing respectively $ apt install flex and $ apt install clang.
I have noticed that if I write flex code for C, process it with $ flex filename, and then compile it with $ gcc -lfl lex.yy.c, everything compiles and the binary works perfectly.
But if I write flex code for C++ (i.e. using C++ only features), process it with $ flex -+ filename and compile it with $ g++ -lfl lex.yy.cc, during compilation an error pops out saying that a file FlexLexer.h, included as
#include <FlexLexer.h>
was not found.
Why does this only happen when using C++? Since I actually need it for C++, how can I fix this issue, minding that I am working on Android using an emulator?
This was a bug in the flex package in Termux and has now been fixed - run apt update && apt upgrade to get the updated package which contains FlexLexer.h.