VK> The AIX xlc 3.6.6 compiler does *NOT* like the INCLUDE_GLUE hackery on a #include. VK> The following test case demonstrates: VK> cd lwlib/ VK> cat > z9.c << EOF VK> #include "config.h" VK> ATHENA_INCLUDE(foobar.h) VK> #include ATHENA_INCLUDE(foobar.h) VK> EOF VK> xlc -E -I. -I/usr/local/include z9.c | tail VK> produces on stderr: VK> "z9.c", line 3.11: 1506-341 (S) #include header must be ended before the end of the line. VK> "z9.c", line 3.10: 1506-234 (E) Expecting a new-line character on #include directive. VK> and on stdout: VK> #line 11 "./../src/s/aix4.h" VK> struct ether_addr; VK> struct sockaddr_dl; VK> #line 2 "z9.c" VK> <X11/Xaw/foobar.h> VK> #line 1 "/usr/local/include/X11" R.> Q..>Sxpm.h>Tbpmplus.h VK> Seems to expand that X11 into the actual directory name. VK> I'm surprised that #including a directory works, this is PROBABLY VK> an IBM bug. I think so. Our code is weird, but legal C. Did our previous incarnation of this code work? It also used preprocessor macros inside a #include directive. Does this work? #include "config.h" #define TMP ATHENA_INCLUDE(foobar.h) #include TMP Martin