Would it be easier to add hasBreadCrumbs field to your page types that use this master? And then you simply use CurrentPage.hasBreadCrumbs to show/hide your footer section?
P.S. If you are really want the macro you may try to see if your web part present in Template XML {% CurrentDocument.DocumentPageTemplate.PageTemplateWebParts.ToString().Contains("breadcrumb") |(identity)GlobalAdministrator%}.
Essenitally you convert the template XML with web parts to string and check if certain string is present or create a custom macro to work with XML :)