This proposal extends the Verilog 1364 include mechanism to define an installation specific include mechanism. This is provided so that the language standard can use the include mechanism to refer to standard extensions to the language that are available in source form. Typically a vendor will provide a tool installation to the customer, embedded within this tool installation or at some other vendor known location, the standard language extensions should be found.

Proposal:

The syntax of the include compiler directive will be as follows:

	include_compiler_directive ::=
		  `include "filename" 
		| `include <filename>

When the filename is an absolute path, only that filename is included.

When the filename is a relative path, then various directories are searched as specified below.

When the double quote ("filename") version is used, the behavior of `include begins exactly like the behavior today which searches the current directory and then any directories specified via a vendor specific command line argument (like XL's +incdir+ option). The only modification is that the system-wide installation is searched by default after all user specified directories.

When the angle bracket ("<>") notation is used, then only the system-wide installation is searched.