List of filename extensions and languages
-----------------------------------------

   If a source file name ends in one of the following extensions, then
GDB infers that its language is the one indicated.

`.mod'
     Modula-2 source file

`.c'
     C source file

`.C'
`.cc'
`.cxx'
`.cpp'
`.cp'
`.c++'
     C++ source file

`.ch'
`.c186'
`.c286'
     CHILL source file.

`.s'
`.S'
     Assembler source file.  This actually behaves almost like C, but
     GDB does not skip over function prologues when stepping.