illumos gate

sysmacros.h contains all sort of questionable content. The following macros can be safely removed.

• major - provided by the DDI/libc
• minor - provided by the DDI/libc
• makedev - provided by the DDI/libc
• bmajor - unused
• emajor - unused
• eminor - unused

A comment in sysmacros.h states:

/*
 * WARNING: The device number macros defined here should not be used by device
 * drivers or user software. Device drivers should use the device functions
 * defined in the DDI/DKI interface (see also ddi.h). Application software
 * should make use of the library routines available in makedev(3). A set of
 * new device macros are provided to operate on the expanded device number
 * format supported in SVR4. Macro versions of the DDI device functions are
 * provided for use by kernel proper routines only. Macro routines bmajor(),
 * major(), minor(), emajor(), eminor(), and makedev() will be removed or
 * their definitions changed at the next major release following SVR4.
 */

So, having these macros for kernel proper use only causes us to:

• keep code that's been slated for removal for a long time
• get either the functions or macros based on which headers are included (and if both are included the order determines what we end up using)