it seems, that the cpp of gcc2.8.1 can't work with all the
back-references in zend.h or php_globals.h. the compilation
breaks at libzend/zend-parser.c with an error, calling a
macro with too few arguments. an analysis shows, that the
macro is CHECK_MEMORY_LIMIT() and the definiton of
_CHECK_MEMORY_LIMIT(s ZEND_FILE_LINE_RELAY_CC) never is resolved.
only the direct entry (s, , __zend_filename, __zend_lineno)
makes it compile. next problem occures with dbase.c and
filepro.c which errors out because of undefined var "core_globals",
which seems to be declared within macros of php_globals.h
I don't know, if this is an error of cpp 2.8.1 or the definition
itself, which looks okay for me, but it should be checked
out and documented.

with threading disabled these errors doesn't occure.