Individual option descriptions
This section contains descriptions of the individual compiler options available in XL C/C++.
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For each option, the following information is provided:
- Category
- The functional category to which the option belongs is listed here.
- Pragma equivalent
- Many compiler options allow you to use an equivalent pragma directive
to apply the option's functionality within the source code, limiting
the scope of the option's application to a single source file, or
even selected sections of code.
When an option supports the #pragma name form of the directive, this is indicated.
- Purpose
- This section provides a brief description of the effect of the option (and equivalent pragmas), and why you might want to use it.
- Syntax
- This section provides the syntax for the option, and where an
equivalent #pragma name is supported, the specific syntax
for the pragma.
Note that you can also use the C99-style _Pragma operator form of any pragma; although this syntax is not provided in the option descriptions. For complete details on pragma syntax, see Pragma directive syntax
- Defaults
- In most cases, the default option setting is clearly indicated in the syntax diagram. However, for many options, there are multiple default settings, depending on other compiler options in effect. This section indicates the different defaults that may apply.
- Parameters
- This section describes the suboptions that are available for the option and pragma equivalents, where applicable. For suboptions that are specific to the command-line option or to the pragma directive, this is indicated in the descriptions.
- Usage
- This section describes any rules or usage considerations you should be aware of when using the option. These can include restrictions on the option's applicability, valid placement of pragma directives, precedence rules for multiple option specifications, and so on.
- Predefined macros
- Many compiler options set macros that are protected (that is, cannot be undefined or redefined by the user). Where applicable, any macros that are predefined by the option, and the values to which they are defined, are listed in this section. A reference list of these macros (as well as others that are defined independently of option setting) is provided in Compiler predefined macros
- Examples
- Where appropriate, examples of the command-line syntax and pragma directive use are provided in this section.
