What does gcc -rpath combined with -W1 mean?

I can see from man gcc that -W has something to do 开发者_JS百科with warnings, but I cannot work out exactly what -W1 would be doing. I am building using the following my Makefile.am:

lib_mysqludf_ssdeep_la_LDFLAGS = -module -avoid-version -no-undefined -rpath @MYSQL_PLUGINDIR@ @SSDEEP_LIBDIR@ @SSDEEP_LIBS@

Just fine on Ubuntu, but RedHat (RHEL) is throwing a 'paths must be absolute error` so after finding a post to the gtk mailing list I tried:

lib_mysqludf_ssdeep_la_LDFLAGS = -module -avoid-version -no-undefined -W1,--rpath -W1,@MYSQL_PLUGINDIR@ @SSDEEP_LIBDIR@ @SSDEEP_LIBS@

Which works, but I cannot see why and I would like to find out before relying upon it as a fix for my Redhat build issue.

Update It looks like redhat is not supplying a path to @MYSQL_PLUGINDIR@ and therefore -rpath is failing.

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Are you sure that is W1 - not Wl (i.e. the letter el ) ?

Look at the Linker options section of gcc's man page