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Compiler-specific Features
4.3.16 __attribute__((visibility("visibility_type")))
This function attribute affects the visibility of ELF symbols.
Note
This attribute is a GNU compiler extension supported by the ARM compiler.
Syntax
__attribute__((visibility("visibility_type")))
Where visibility_type is one of the following:
default
hidden
internal
protected
The assumed visibility of symbols can be changed by other options.
Default visibility overrides such changes. Default visibility corresponds
to external linkage.
The symbol is not placed into the dynamic symbol table, so no other
executable or shared library can directly reference it. Indirect references
are possible using function pointers.
Unless otherwise specified by the processor-specific Application Binary
Interface (psABI), internal visibility means that the function is never
called from another module.
The symbol is placed into the dynamic symbol table, but references
within the defining module bind to the local symbol. That is, the symbol
cannot be overridden by another module.
Usage
Except when specifying default visibility, this attribute is intended for use with
declarations that would otherwise have external linkage.
You can use this attribute in C and C++. In C++, it can also be applied to types, member
functions, and namespace declarations.
Example
void __attribute__((visibility(“internal”))) foo()
{
...
}
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