GCC Options

GCC, the GNU Compiler Collection, is a compiler system, part of the GNU toolchain, produced by the GNU Project.

It provides frontends for C, C++, Java, Ada, Go, etc.

GCC (Wikipedia)

GCC Manual

Install GCC

In Debian:
$ sudo aptitude install gcc

Query GCC Version

$ gcc --version
gcc (Debian 5.3.1-8) 5.3.1 20160205
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO


Get basic help:
$ gcc --help

Usage: gcc [options] file...
-pass-exit-codes Exit with highest error code from a phase
--help Display this information
--target-help Display target specific command line options
Display specific types of command line options
(Use '-v --help' to display command line options of sub-processes)
--version Display compiler version information
-dumpspecs Display all of the built in spec strings
-dumpversion Display the version of the compiler
-dumpmachine Display the compiler's target processor
-print-search-dirs Display the directories in the compiler's search path
-print-libgcc-file-name Display the name of the compiler's companion library
-print-file-name= Display the full path to library
-print-prog-name= Display the full path to compiler component
-print-multiarch Display the target's normalized GNU triplet, used as
a component in the library path
-print-multi-directory Display the root directory for versions of libgcc
-print-multi-lib Display the mapping between command line options and
multiple library search directories
-print-multi-os-directory Display the relative path to OS libraries
-print-sysroot Display the target libraries directory
-print-sysroot-headers-suffix Display the sysroot suffix used to find headers
-Wa, Pass comma-separated on to the assembler
-Wp, Pass comma-separated on to the preprocessor
-Wl, Pass comma-separated on to the linker
-Xassembler Pass on to the assembler
-Xpreprocessor Pass on to the preprocessor
-Xlinker Pass on to the linker
-save-temps Do not delete intermediate files
-save-temps= Do not delete intermediate files
-no-canonical-prefixes Do not canonicalize paths when building relative
prefixes to other gcc components
-pipe Use pipes rather than intermediate files
-time Time the execution of each subprocess
-specs= Override built-in specs with the contents of
-std= Assume that the input sources are for
--sysroot= Use as the root directory for headers
and libraries
-B Add to the compiler's search paths
-v Display the programs invoked by the compiler
-### Like -v but options quoted and commands not executed
-E Preprocess only; do not compile, assemble or link
-S Compile only; do not assemble or link
-c Compile and assemble, but do not link
-o Place the output into
-pie Create a position independent executable
-shared Create a shared library
-x Specify the language of the following input files
Permissible languages include: c c++ assembler none
'none' means revert to the default behavior of
guessing the language based on the file's extension

Options starting with -g, -f, -m, -O, -W, or --param are automatically
passed on to the various sub-processes invoked by gcc. In order to pass
other options on to these processes the -W options must be used.

Display enabled options

$ gcc -Q -v file

Display enabled options in compiler and subprocesses.

If we set no options it shows default ones.

Debug symbols

$ gcc -g

Add debugging info in the operating system native format. This info is useful for gdb.

It is allowed to use -g option together with optimization ones.


Without compilation options (or -O0) compiler tries to minimize compilation time.

Optimize to reduce code size
$ gcc -Os

Optimize for speed
$ gcc -O1
$ gcc -O2
$ gcc -O3

The higher the number the more optimizations enabled.

-O0 means no optimization enabled.

Preprocess only

$ gcc -E file

Only preprocess the code. Stop after preprocessing the code.

Show the assembler code

$ gcc -S file

Stop after preprocessing and compilation (do not assemble the code).


$ man gcc