Using and Porting GNU CC

3.3: Compiling C++ Programs

C++ source files conventionally use one of the suffixes `.C', `.cc', or `.cxx'; preprocessed C++ files use the suffix `.ii'. GNU CC recognizes files with these names and compiles them as C++ programs even if you call the compiler the same way as for compiling C programs (usually with the name gcc).

However, C++ programs often require class libraries as well as a compiler that understands the C++ language---and under some circumstances, you might want to compile programs from standard input, or otherwise without a suffix that flags them as C++ programs. g++ is a program that calls GNU CC with the default language set to C++, and automatically specifies linking against the GNU class library libg++. [1] On many systems, the script g++ is also installed with the name c++.

When you compile C++ programs, you may specify many of the same command-line options that you use for compiling programs in any language; or command-line options meaningful for C and related languages; or options that are meaningful only for C++ programs. See C Dialect Options, for explanations of options for languages related to C. See C++ Dialect Options, for explanations of options that are meaningful only for C++ programs.

[1] Prior to release 2 of the compiler, there was a separate g++ compiler. That version was based on GNU CC, but not integrated with it. Versions of g++ with a `1.xx' version number---for example, g++ version 1.37 or 1.42---are much less reliable than the versions integrated with GCC 2. Moreover, combining G++ `1.xx' with a version 2 GCC will simply not work.