In large software development projects, when a programmer is assigned a bug to fix, she typically spends a lot of time searching (in an ad-hoc manner) for instances from the past where similar bugs have been debugged, analyzed and resolved. Systematic search tools that allow the programmer to express the context of the current bug, and search through diverse data repositories associated with large projects can greatly improve the productivity of debugging This paper presents the design, implementation and experience from such a search tool called DebugAdvisor.

We present a crosslingual location search service that works across multiple countries and deals effectively with ambiguous and ill-formed queries. The system returns a ranked list of spatial regions (points, lines and polygons) that best match users' text queries, which can range from postal addresses to unstructured queries that list a few col-located map features. The system's robustness comes from a novel approach that exploits spatial coherence to identify viable interpretations of input text. Unlike existing state of the art geocoding systems, our system requires no region-specific rules, training or customization, and thus may be built to cover any region for which detailed map data is available, making it possible, for the first time, to rapidly build location search services for new regions, and more generally, approximate text search over arbitrary spatial repositories. Our system has been shown to outperform commercial geocoding systems, especially when spelling or format variations are introduced. We demonstrate our sys-tem's capabilities by showing results for a variety of text queries over a large dataset from several countries with widely differing address formats.

Asynchronous systems programs are usually written in an event-driven style which is tailored for performance rather than analyzability. Such programs have non-sequential control ow and make heavy use of heap data structures to store and retrieve state related to pending operations. As a result, existing tools that analyze sequential programs are ine ective in analyzing asynchronous systems components. We describe clarity, a programming language that enables analyzable design of asynchronous components. clarity has three novel features: (1) Nonblocking function calls that allow event-driven code to be written in a sequential style. If a blocking statement is encountered during the execution of such a call, the call returns and the remainder of the operation is automatically queued for later execution. (2) Coords, a set of high-level coordination primitives, encapsulate common interactions between asynchronous components and make high-level coordination protocols explicit. (3) Linearity annotations delegate coord protocol obligations to exactly one thread at each asynchronous function call, transforming a concurrent analysis problem into a sequential one. We demonstrate how these language features enable both a more intuitive expression of program logic and more e ective program analysis most checking is done using simple sequential analysis. We describe our experience in developing, testing, and analyzing a network device driver using clarity. 1.