{"id":418112,"date":"2017-07-30T22:10:10","date_gmt":"2017-07-31T05:10:10","guid":{"rendered":"https:\/\/www.microsoft.com\/en-us\/research\/?post_type=msr-research-item&#038;p=418112"},"modified":"2019-02-02T22:02:54","modified_gmt":"2019-02-03T06:02:54","slug":"precise-null-pointer-analysis-global-value-numbering","status":"publish","type":"msr-research-item","link":"https:\/\/www.microsoft.com\/en-us\/research\/publication\/precise-null-pointer-analysis-global-value-numbering\/","title":{"rendered":"Precise null-pointer analysis using Global Value Numbering"},"content":{"rendered":"<p style=\"text-align: left\">Precise analysis of pointer information plays an important role in many static<br \/>\nanalysis tools. The precision, however, must be balanced<br \/>\nagainst the scalability of the analysis. This paper focusses on improving the<br \/>\nprecision of standard context and flow insensitive alias analysis algorithms<br \/>\nat a low scalability cost. In particular, we present a semantics-preserving<br \/>\nprogram transformation that drastically improves the precision of existing<br \/>\nanalyses when deciding if a pointer can alias <em>null<\/em>.<br \/>\nOur program transformation is based on Global Value Numbering, a scheme<br \/>\ninspired from compiler optimization literature. It allows even a flow-insensitive<br \/>\nanalysis to make use of branch conditions such as checking if a pointer is <em>null<\/em><br \/>\nand gain precision.<\/p>\n<p style=\"text-align: left\">We perform experiments on real-world code and show<br \/>\nthat the transformation improves precision (in terms of the number of dereferences proved safe)<br \/>\nfrom 86.56% to 98.05%, while incurring a small overhead in the running time.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Precise analysis of pointer information plays an important role in many static analysis tools. The precision, however, must be balanced against the scalability of the analysis. This paper focusses on improving the precision of standard context and flow insensitive alias analysis algorithms at a low scalability cost. In particular, we present a semantics-preserving program transformation [&hellip;]<\/p>\n","protected":false},"featured_media":0,"template":"","meta":{"msr-url-field":"","msr-podcast-episode":"","msrModifiedDate":"","msrModifiedDateEnabled":false,"ep_exclude_from_search":false,"_classifai_error":"","footnotes":""},"msr-content-type":[3],"msr-research-highlight":[],"research-area":[13560],"msr-publication-type":[193716],"msr-product-type":[],"msr-focus-area":[],"msr-platform":[],"msr-download-source":[],"msr-locale":[268875],"msr-post-option":[],"msr-field-of-study":[],"msr-conference":[],"msr-journal":[],"msr-impact-theme":[],"msr-pillar":[],"class_list":["post-418112","msr-research-item","type-msr-research-item","status-publish","hentry","msr-research-area-programming-languages-software-engineering","msr-locale-en_us"],"msr_publishername":"","msr_edition":"","msr_affiliation":"","msr_published_date":"2017-7-1","msr_host":"","msr_duration":"","msr_version":"","msr_speaker":"","msr_other_contributors":"","msr_booktitle":"","msr_pages_string":"","msr_chapter":"","msr_isbn":"","msr_journal":"","msr_volume":"","msr_number":"","msr_editors":"","msr_series":"","msr_issue":"","msr_organization":"","msr_how_published":"","msr_notes":"","msr_highlight_text":"","msr_release_tracker_id":"","msr_original_fields_of_study":"","msr_download_urls":"","msr_external_url":"","msr_secondary_video_url":"","msr_longbiography":"","msr_microsoftintellectualproperty":1,"msr_main_download":"418121","msr_publicationurl":"","msr_doi":"","msr_publication_uploader":[{"type":"file","viewUrl":"https:\/\/www.microsoft.com\/en-us\/research\/wp-content\/uploads\/2017\/07\/main.pdf","id":"418121","title":"main","label_id":"243109","label":0}],"msr_related_uploader":"","msr_attachments":[],"msr-author-ordering":[{"type":"text","value":"Ankush Das","user_id":0,"rest_url":false},{"type":"user_nicename","value":"Akash Lal","user_id":30905,"rest_url":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/microsoft-research\/v1\/researchers?person=Akash Lal"}],"msr_impact_theme":[],"msr_research_lab":[],"msr_event":[],"msr_group":[],"msr_project":[325037,171153],"publication":[],"video":[],"download":[],"msr_publication_type":"inproceedings","related_content":{"projects":[{"ID":325037,"post_title":"Angelic Verification","post_name":"angelic-verification","post_type":"msr-project","post_date":"2016-11-20 23:16:16","post_modified":"2019-11-19 11:02:20","post_status":"publish","permalink":"https:\/\/www.microsoft.com\/en-us\/research\/project\/angelic-verification\/","post_excerpt":"Angelic verification (AV) brings the benefits of static assertion checking to production software without inundating users with false alarms and not burdening them with upfront modeling. In other words, the goal of AV is to democratize static assertion checking for any developer.","_links":{"self":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-project\/325037"}]}},{"ID":171153,"post_title":"Corral Program Verifier","post_name":"q-program-verifier","post_type":"msr-project","post_date":"2013-05-19 09:16:29","post_modified":"2020-10-04 23:48:07","post_status":"publish","permalink":"https:\/\/www.microsoft.com\/en-us\/research\/project\/q-program-verifier\/","post_excerpt":"Corral is a\u00a0whole-program analysis tool for Boogie programs. Corral uses goal-directed symbolic search techniques to find assertion violations.\u00a0It leverages the powerful\u00a0theorem prover Z3. It is available open source on\u00a0GitHub.\u00a0Corral, by default, does a bounded search up to a recursion depth and fixed number of context switches. Corral also supports the Duality extension for constructing\u00a0inductive proofs of correctness of programs. New: Microsoft Static Driver Verifier Benchmarks Corral powers Microsoft's Static Driver Verifier tool. This work has&hellip;","_links":{"self":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-project\/171153"}]}}]},"_links":{"self":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-item\/418112"}],"collection":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-item"}],"about":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/types\/msr-research-item"}],"version-history":[{"count":3,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-item\/418112\/revisions"}],"predecessor-version":[{"id":565758,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-item\/418112\/revisions\/565758"}],"wp:attachment":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/media?parent=418112"}],"wp:term":[{"taxonomy":"msr-content-type","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-content-type?post=418112"},{"taxonomy":"msr-research-highlight","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-highlight?post=418112"},{"taxonomy":"msr-research-area","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/research-area?post=418112"},{"taxonomy":"msr-publication-type","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-publication-type?post=418112"},{"taxonomy":"msr-product-type","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-product-type?post=418112"},{"taxonomy":"msr-focus-area","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-focus-area?post=418112"},{"taxonomy":"msr-platform","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-platform?post=418112"},{"taxonomy":"msr-download-source","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-download-source?post=418112"},{"taxonomy":"msr-locale","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-locale?post=418112"},{"taxonomy":"msr-post-option","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-post-option?post=418112"},{"taxonomy":"msr-field-of-study","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-field-of-study?post=418112"},{"taxonomy":"msr-conference","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-conference?post=418112"},{"taxonomy":"msr-journal","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-journal?post=418112"},{"taxonomy":"msr-impact-theme","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-impact-theme?post=418112"},{"taxonomy":"msr-pillar","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-pillar?post=418112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}