Re: [PATCH] configure: use AC_SEARCH_LIBS instead of AC_CHECK_LIB

Paolo Bonzini wrote:

quoted

With AC_SEARCH_LIBS, which of [action-if-found] or [action-if-not-found]
is executed if the function is found in the standard c library i.e.
"calling
`AC_LINK_IFELSE([AC_LANG_CALL([], [function])])' first with no
libraries"?
Is the answer neither?  If the answer is [action-if-found], won't the
NEEDS_LIBGEN=YesPlease be set when the function is found in the c
library?

It evaluates the action-if-found and adds nothing to LIBS.  Instead, if
it is found in a library, it evaluates the action-if-found after adding
(actually prepending) -lBLAH to LIBS.

That's what I suspected.  It means we can't have NEEDS_SOMETHING=true in
the action-if-found parameter when using AC_SEARCH_LIBS since that may cause
the Makefile to append a library requirement when none is necessary.

-brandon