NAME
       gcc - GNU project C and C++ compiler

SYNOPSIS
       gcc [-c-S-E] [-std=standard]
           [-g] [-pg] [-Olevel]
           [-Wwarn...] [-pedantic]
           [-Idir...] [-Ldir...]
           [-Dmacro[=defn]...] [-Umacro]
           [-foption...] [-mmachine-option...]
           [-o outfile] infile...

       Only the most useful options are listed here; see below for the remainder.  g++ accepts mostly the same
       options as gcc.

DESCRIPTION
       When you invoke GCC, it normally does preprocessing, compilation, assembly and linking.  The "overall
       options" allow you to stop this process at an intermediate stage.  For example, the -c option says not
       to run the linker.  Then the output consists of object files output by the assembler.

       Other options are passed on to one stage of processing.  Some options control the preprocessor and oth-
       ers the compiler itself.  Yet other options control the assembler and linker; most of these are not doc-
       umented here, since you rarely need to use any of them.

       Most of the command line options that you can use with GCC are useful for C programs; when an option is
       only useful with another language (usually C++), the explanation says so explicitly.  If the description
       for a particular option does not mention a source language, you can use that option with all supported
       languages.

       The gcc program accepts options and file names as operands.  Many options have multi-letter names;
       therefore multiple single-letter options may not be grouped: -dr is very different from -d -r.

       You can mix options and other arguments.  For the most part, the order you use doesn't matter.  Order
       does matter when you use several options of the same kind; for example, if you specify -L more than
       once, the directories are searched in the order specified.

       Many options have long names starting with -f or with -W---for example, -fstrength-reduce, -Wformat and
       so on.  Most of these have both positive and negative forms; the negative form of -ffoo would be
       -fno-foo.  This manual documents only one of these two forms, whichever one is not the default.

http://bashconsole.org/man.1.gcc