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. Where an option supports the #pragma options option_name and/or #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. Syntax for #pragma options option_name forms of the pragma is not provided, as this
is normally identical to that of the option. 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.