+dnl gcc 3.4 has a pch bug which truncates wide character constants in headers.
+dnl Hopefully for a non-unicode build there aren't any wide constants in
+dnl headers, but for a unicode build it's best to disable pch.
+if test "$wxUSE_UNICODE" = yes -a "$GCC" = yes -a "$bk_use_pch" != no
+then
+ AC_CACHE_CHECK(
+ [for gcc precompiled header bug],
+ [wx_cv_gcc_pch_bug],
+ [[
+ wx_cv_gcc_pch_bug=no
+ echo 'const wchar_t test_var[] = L"wide string";' > conftest.h
+
+ if $CXX conftest.h >& /dev/null
+ then
+ {
+ echo '#include "conftest.h"'
+ echo 'const wchar_t *test() { return test_var; }'
+ } > conftest.cpp
+
+ if $CXX -c -o conftest.o conftest.cpp >& /dev/null
+ then
+ tr -dc 'a-z' < conftest.o |
+ grep 'widestring' >& /dev/null ||
+ wx_cv_gcc_pch_bug=yes
+ fi
+ fi
+
+ rm -f conftest.h conftest.gch conftest.cpp conftest.o
+ ]])
+
+ if test "$wx_cv_gcc_pch_bug" = yes; then
+ dnl make the default for pch 'no'
+ dnl further below check whether the user overrode and warn them
+ bk_use_pch=no
+ fi
+fi
+