-qroconst
Category
Purpose
Specifies the storage location for constant values.
When roconst is in effect, constants are placed in read-only storage. When noroconst is in effect, constants are placed in read/write storage.
Defaults
-qroconst for all compiler invocations except cc and
its derivatives. -qnoroconst for the cc invocation
and its derivatives.
-qroconst
Usage
Placing constant values in read-only memory can improve runtime performance, save storage, and provide shared access. However, code that attempts to modify a read-only constant value generates a memory error.
"Constant" in the context
of the -qroconst option refers to variables that
are qualified by const, including const-qualified
characters, integers, floats, enumerations, structures, unions, and
arrays. The following constructs are not affected by this option:
- Variables qualified with volatile and aggregates (such as a structure or a union) that contain volatile variables
- Pointers and complex aggregates containing pointer members
- Automatic and static types with block scope
- Uninitialized types
- Regular structures with all members qualified by const
- Initializers that are addresses, or initializers that are cast to non-address values
The -qroconst option does not imply the -qro option. Both options must be specified if you want to specify storage characteristics of both string literals (-qro) and constant values (-qroconst).
Predefined macros
None.
Related information
