# Warnings

• -Wall

Show all warnings.

• -Werror

Show warnings as errors.

• -fsyntax-only

Check the code for syntax errors, but don't do anything beyond that.

• -pedantic

Issue all the warnings demanded by strict ISO C, reject all programs that use forbidden extensions, and some other programs that do not follow ISO C. Valid ISO C programs should compile properly with or without this option (though a rare few will require -ansi or a -std option specifying the required version of ISO C). However, without this option, certain GNU extensions and traditional C features are supported as well. With this option, they are rejected.

• -pedantic-errors

Pedantic warnings are produced as errors.

• -w

Inhibit all warning messages.