Help with 3.4.x compilation problem

[Mick Jordan <mick.jordan@oracle.com>]

I am having a problem compiling a tools component of my variant of 
mini-os against a 3.4.x source tree, having recently migrated from 
3.1.4. The problem lies in the header file xenctrl.h, which contains 
this (new from 3.1.4) code:

#if defined(__i386__) || defined(__x86_64__)
#include <xen/foreign/x86_32.h>
#include <xen/foreign/x86_64.h>
#endif

Now, this look extremely dubious to me as both 32 and 64 bit headers are 
not usually included at the same time, but the immediate problem is that 
the headers cannot be found:

[ -e xen ] || ln -sf /import/xen/xen-3.4.2/xen/include/public xen
gcc  -DPIC -O2 -fomit-frame-pointer -m64 -fno-strict-aliasing -std=gnu99 
-Wall -Wstrict-prototypes -Wno-unused-value 
-Wdeclaration-after-statement  -D__XEN_TOOLS__ -MMD -MF 
.db-xenbus.opic.d  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE  -Werror 
-Wno-unused -fno-strict-aliasing -I /import/xen/xen-3.4.2/tools/libxc -I 
/import/xen/xen-3.4.2/tools/xenstore -I. -D_GNU_SOURCE 
-Wp,-MD,.db-xenbus.opic.d -fPIC -c -o db-xenbus.opic db-xenbus.c
gcc  -DPIC -O2 -fomit-frame-pointer -m64 -fno-strict-aliasing -std=gnu99 
-Wall -Wstrict-prototypes -Wno-unused-value 
-Wdeclaration-after-statement  -D__XEN_TOOLS__ -MMD -MF 
.db-frontend.opic.d  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE  -Werror 
-Wno-unused -fno-strict-aliasing -I /import/xen/xen-3.4.2/tools/libxc -I 
/import/xen/xen-3.4.2/tools/xenstore -I. -D_GNU_SOURCE 
-Wp,-MD,.db-frontend.opic.d -fPIC -c -o db-frontend.opic db-frontend.c
In file included from db-frontend.c:42:
/import/xen/xen-3.4.2/tools/libxc/xenctrl.h:36:32: error: 
xen/foreign/x86_32.h: No such file or directory
/import/xen/xen-3.4.2/tools/libxc/xenctrl.h:37:32: error: 
xen/foreign/x86_64.h: No such file or directory

I've searched the source tree and indeed cannot find any directory named 
foreign. However, I can find some directories containing the pattern 
foreign, e.g., tools/include/xen-foreign,  so I am guessing that some 
symbolic link hackery is done in a normal build that sets this up. I say 
"normal" because, for various reasons, I do not build my mini-os variant 
inside the Xen tree but rather refer to it via an environment variable. 
This worked fine in 3.1.4.

Times like this I wish there was a developer's manual.

Thanks for any help.

Mick