The Austin Group this morning accepted proposed wording to standardize both MAP_ANON and MAP_ANONYMOUS, recognizing that neither was clearly more popular than the other among applications, and that there's precedent in POSIX for simply standardizing multiple spellings for a feature when both are common and trivial for implementations to provide (e.g., PAGE_SIZE and PAGESIZE).
Diff below defines MAP_ANONYMOUS as a synonym for MAP_ANON, keeping MAP_ANON as canonical in following BSD heritage. ok? Index: lib/libc/sys/mmap.2 =================================================================== RCS file: /cvs/src/lib/libc/sys/mmap.2,v retrieving revision 1.50 diff -u -p -r1.50 mmap.2 --- lib/libc/sys/mmap.2 2 Jul 2014 22:22:35 -0000 1.50 +++ lib/libc/sys/mmap.2 10 Jul 2014 18:32:59 -0000 @@ -121,7 +121,7 @@ Sharing, mapping type, and options are s .Fa flags argument by OR'ing the following values. Exactly one of the first two values must be specified: -.Bl -tag -width MAP_PRIVATE -offset indent +.Bl -tag -width MAP_ANONYMOUS -offset indent .It Dv MAP_PRIVATE Modifications are private. .It Dv MAP_SHARED @@ -129,13 +129,16 @@ Modifications are shared. .El .Pp Any combination of the following flags may additionally be used: -.Bl -tag -width MAP_PRIVATE -offset indent +.Bl -tag -width MAP_ANONYMOUS -offset indent .It Dv MAP_ANON Map anonymous memory not associated with any specific file. The file descriptor used for creating .Dv MAP_ANON must currently be \-1 indicating no name is associated with the region. +.It Dv MAP_ANONYMOUS +Synonym for +.Dv MAP_ANON . .It Dv MAP_FIXED Demand that the mapping is placed at .Fa addr , @@ -157,7 +160,7 @@ source compatibility with code written f but are not recommended for use in new .Ox code: -.Bl -tag -width MAP_PRIVATE -offset indent +.Bl -tag -width MAP_ANONYMOUS -offset indent .It Dv MAP_COPY Modifications are private and, unlike .Dv MAP_PRIVATE , Index: sys/sys/mman.h =================================================================== RCS file: /cvs/src/sys/sys/mman.h,v retrieving revision 1.25 diff -u -p -r1.25 mman.h --- sys/sys/mman.h 27 Jun 2014 20:50:43 -0000 1.25 +++ sys/sys/mman.h 10 Jul 2014 18:32:59 -0000 @@ -57,6 +57,7 @@ #define MAP_FIXED 0x0010 /* map addr must be exactly as requested */ #define __MAP_NOREPLACE 0x0800 /* fail if address not available */ #define MAP_ANON 0x1000 /* allocated from memory, swap space */ +#define MAP_ANONYMOUS MAP_ANON /* alternate POSIX spelling */ #define MAP_FLAGMASK 0x1ff7
