On 13 March 2017 at 16:20, ryxi@xxxxxxxxxxxxxxxxx wrote: > Hi, > > man 1 g++ said "file.c" is considered unpreprocessed C source file. But in fact g++ would compile it as C++ source. Why does g++ behave this way? Should we make it clear in g++ doc? It's documented at https://gcc.gnu.org/onlinedocs/gcc/Invoking-G_002b_002b.html