Use the -xpchstop=file option to specify the last include file to be considered in creating the precompile-header file with the -xpch option. Using -xpchstop on the command line is equivalent to placing a hdrstop pragma after the first include-directive that references file in each of the source files that you specify with the cc command.
In the following example, the -xpchstop option specifies that the viable prefix for the precompiled header file ends with the include of projectheader.h. Therefore, privateheader.h is not a part of the viable prefix.
example% cat a.cc
#include <stdio.h>
#include <strings.h>
#include "projectheader.h"
#include "privateheader.h"
.
.
.
example% CC -xpch=collect:foo.Cpch a.cc -xpchstop=projectheader.h -c
|
-xpch, pragma hdrstop