{"id":597,"date":"2010-04-29T21:40:10","date_gmt":"2010-04-30T02:40:10","guid":{"rendered":"http:\/\/vgable.com\/blog\/?p=597"},"modified":"2010-04-29T21:40:13","modified_gmt":"2010-04-30T02:40:13","slug":"what-am-i-about-to-call","status":"publish","type":"post","link":"https:\/\/vgable.com\/blog\/2010\/04\/29\/what-am-i-about-to-call\/","title":{"rendered":"What Am I About To Call?"},"content":{"rendered":"<p>Say you&#8217;re in gdb, and about to execute a <code>call<\/code> instruction for <code>dyld_stub_objc_msgSend<\/code>, how do you know what&#8217;s about to happen?<\/p>\n<h3>On i386<\/h3>\n<pre>(gdb) x\/s *(SEL*)($esp+4)<\/pre>\n<p>tells you the <strong>message<\/strong> that&#8217;s about to be sent.<\/p>\n<pre>(gdb) po *(id*)$esp<\/pre>\n<p>tells you the <strong>target<\/strong> object that&#8217;s about to get the message.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Say you&#8217;re in gdb, and about to execute a call instruction for dyld_stub_objc_msgSend, how do you know what&#8217;s about to happen? On i386 (gdb) x\/s *(SEL*)($esp+4) tells you the message that&#8217;s about to be sent. (gdb) po *(id*)$esp tells you the target object that&#8217;s about to get the message.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,203,3,5,4,93,10],"tags":[77,575,23],"class_list":["post-597","post","type-post","status-publish","format-standard","hentry","category-cocoa","category-iphone","category-macosx","category-objective-c","category-programming","category-reverse-engineering","category-tips","tag-debugging","tag-gdb","tag-x86"],"_links":{"self":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts\/597","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/comments?post=597"}],"version-history":[{"count":1,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts\/597\/revisions"}],"predecessor-version":[{"id":598,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts\/597\/revisions\/598"}],"wp:attachment":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/media?parent=597"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/categories?post=597"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/tags?post=597"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}