Compiler options perform a wide variety of functions, such as setting compiler characteristics, describing the object code and compiler output to be produced, and performing some preprocessor functions. You can specify compiler options in one or more of the following ways:
The compiler assumes default settings for most compiler options not explicitly set by you in the ways listed above.
When specifying compiler options, it is possible for option conflicts and incompatibilities to occur. XL C/C++ resolves most of these conflicts and incompatibilities in a consistent fashion, as follows:
In most cases, the compiler uses the following order in resolving conflicting or incompatible options:
Option conflicts that do not follow this priority sequence are described in Resolving conflicting compiler options.