gcc: Invoking GCC

1 
1 3 GCC Command Options
1 *********************
1 
1 When you invoke GCC, it normally does preprocessing, compilation,
1 assembly and linking.  The "overall options" allow you to stop this
1 process at an intermediate stage.  For example, the '-c' option says not
1 to run the linker.  Then the output consists of object files output by
11 the assembler.  ⇒Options Controlling the Kind of Output Overall
 Options.
1 
1  Other options are passed on to one or more stages of processing.  Some
1 options control the preprocessor and others the compiler itself.  Yet
1 other options control the assembler and linker; most of these are not
1 documented here, since you rarely need to use any of them.
1 
1  Most of the command-line options that you can use with GCC are useful
1 for C programs; when an option is only useful with another language
1 (usually C++), the explanation says so explicitly.  If the description
1 for a particular option does not mention a source language, you can use
1 that option with all supported languages.
1 
1  The usual way to run GCC is to run the executable called 'gcc', or
1 'MACHINE-gcc' when cross-compiling, or 'MACHINE-gcc-VERSION' to run a
1 specific version of GCC. When you compile C++ programs, you should
11 invoke GCC as 'g++' instead.  ⇒Compiling C++ Programs Invoking
 G++, for information about the differences in behavior between 'gcc' and
1 'g++' when compiling C++ programs.
1 
1  The 'gcc' program accepts options and file names as operands.  Many
1 options have multi-letter names; therefore multiple single-letter
1 options may _not_ be grouped: '-dv' is very different from '-d -v'.
1 
1  You can mix options and other arguments.  For the most part, the order
1 you use doesn't matter.  Order does matter when you use several options
1 of the same kind; for example, if you specify '-L' more than once, the
1 directories are searched in the order specified.  Also, the placement of
1 the '-l' option is significant.
1 
1  Many options have long names starting with '-f' or with '-W'--for
1 example, '-fmove-loop-invariants', '-Wformat' and so on.  Most of these
1 have both positive and negative forms; the negative form of '-ffoo' is
1 '-fno-foo'.  This manual documents only one of these two forms,
1 whichever one is not the default.
1 
1  ⇒Option Index, for an index to GCC's options.
1 

Menu

1 
· Option Summary      Brief list of all options, without explanations.
· Overall Options     Controlling the kind of output:
1                         an executable, object files, assembler files,
1                         or preprocessed source.
· Invoking G++        Compiling C++ programs.
· C Dialect Options   Controlling the variant of C language compiled.
· C++ Dialect Options Variations on C++.
· Objective-C and Objective-C++ Dialect Options Variations on Objective-C
1                         and Objective-C++.
· Diagnostic Message Formatting Options Controlling how diagnostics should
1                         be formatted.
· Warning Options     How picky should the compiler be?
· Debugging Options   Producing debuggable code.
· Optimize Options    How much optimization?
· Instrumentation Options Enabling profiling and extra run-time error checking.
· Preprocessor Options Controlling header files and macro definitions.
1                          Also, getting dependency information for Make.
· Assembler Options   Passing options to the assembler.
· Link Options        Specifying libraries and so on.
· Directory Options   Where to find header files and libraries.
1                         Where to find the compiler executable files.
· Code Gen Options    Specifying conventions for function calls, data layout
1                         and register usage.
· Developer Options   Printing GCC configuration info, statistics, and
1                         debugging dumps.
· Submodel Options    Target-specific options, such as compiling for a
1                         specific processor variant.
· Spec Files          How to pass switches to sub-processes.
· Environment Variables Env vars that affect GCC.
· Precompiled Headers Compiling a header once, and using it many times.
1