__attribute__
This section describes the syntax with which __attribute__ may be used, and the constructs to which attribute specifiers bind.
An attribute specifier is of the form __attribute__ ((attribute-list)).
This syntax is taken directly from GCC but unlike GCC, which allows attributes to be applied only to functions, types, and variables, OpenCL attributes can be associated with:
attributes-types(3clc)
functionQualifiers(3clc)
attributes-variables(3clc)
attributes-blocksAndControlFlow(3clc)
attributes-blocksAndControlFlow(3clc)
In general, the rules for how an attribute binds for a given context are non-trivial and the reader is pointed to GCC's documentation and Maurer and Wong's paper (See the "References" section in the \m[blue]OpenCL specification\m[]\s-2\u[1]\d\s+2 for details.)
\m[blue]OpenCL Specification\m[]\s-2\u[2]\d\s+2
attributes-types(3clc), attributes-variables(3clc), attributes-blocksAndControlFlow(3clc), functionQualifiers(3clc)
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OpenCL specification
page 355, section 11 - References (to Wong paper)
OpenCL Specification
page 236, section 6.11. - Attribute Qualifiers