Eine wichtige Aufgabe bei der Softwareentwicklung ist das Auffinden von Fehlern und das Verstehen ihrer Ursachen. Zur Unterstützung dieser Aufgabe gibt es zahlreiche De-bugger. Bei der Nutzung von Softwaregeneratoren benötigt man zum Debuggen spezielle Informationen. In dieser Arbeit werden Anforderungen an einen Debugger für Software-generatoren definiert. Dazu werden zunächst strukturell ähnliche Softwaregeneratoren auf ihre Debugger untersucht und grundsätzliche Debuggertypen identifiziert. Aus diesen werden 15 Anforderungen formuliert, die der hier beispielhaft betrachtete Softwaregener-ator erfüllen soll. Anschließend erfolgen eine Verallgemeinerung der Ergebnisse und eine kurze Diskussion der Umsetzung auf der Plattform JetBrains MPS.

The Lissom project deals with the hardware-software co-design methodology. In this project, an integrated desktop environment for a design of multiprocessor systems on chip was developed. This environment can be used also for developing applications for multiprocessor systems. One part of the environment is a debugger that can be used to debug single core systems. In this thesis, a single processor debugger tool is described in detail and an extension to this tool is proposed and implemented based on the Nexus standard. The extended debugger allows debugging of multiprocessor systems.

<p>Debugging applications that are running in embedded systems is becoming harder and harder due to the growing complexity of the systems. This is especially true for embedded systems that are developed for the automotive market.</p><p>To aid the debugging there are tools called debuggers. Historically, debuggers have been implemented by using a debug port to connect a software debugger running at the developer machine to dedicated on-chip debugging hardware. The problem with this approach is that it is expensive and that it is not possible to use it if the debug port on the system is not available.Therefore there is a demand for user-friendly debuggers that are not as expensive and require no extra hardware.</p><p>This report presents alternatives to debugging embedded systems. From these alternatives a completely software based debugger solution called monitor-based debugging is selected and acts as a foundation for an implementation that is described in the report. The implementation uses GNU Debugger (GDB) and its remote debugging capabilities to perform debugging.</p><p>The implemented debugger is evaluated by using it to debug applications that are running in a powertrain control unit in a modern truck. It is also compared to two commercial hardware based debuggers. In the evaluation it is found that the debugger functionalities and user-friendliness are on par with the commercial alternatives, but that it lacks some in its non-intrusive capabilities when comparing it with the high-end alternatives on the market.</p>

Debugging applications that are running in embedded systems is becoming harder and harder due to the growing complexity of the systems. This is especially true for embedded systems that are developed for the automotive market. To aid the debugging there are tools called debuggers. Historically, debuggers have been implemented by using a debug port to connect a software debugger running at the developer machine to dedicated on-chip debugging hardware. The problem with this approach is that it is expensive and that it is not possible to use it if the debug port on the system is not available.Therefore there is a demand for user-friendly debuggers that are not as expensive and require no extra hardware. This report presents alternatives to debugging embedded systems. From these alternatives a completely software based debugger solution called monitor-based debugging is selected and acts as a foundation for an implementation that is described in the report. The implementation uses GNU Debugger (GDB) and its remote debugging capabilities to perform debugging. The implemented debugger is evaluated by using it to debug applications that are running in a powertrain control unit in a modern truck. It is also compared to two commercial hardware based debuggers. In the evaluation it is found that the debugger functionalities and user-friendliness are on par with the commercial alternatives, but that it lacks some in its non-intrusive capabilities when comparing it with the high-end alternatives on the market.

abstract: Debugging is a hard task. Debugging multi-threaded applications with their inherit non-determinism is all the more difficult. Non-determinism of any kind adds to the difficulty of cyclic debugging. In Android applications which are written in Java, threads and concurrency constructs introduce non-determinism to the program execution. Even with the same input, consecutive runs may not be the same and reproducing the same bug is a challenging task. This makes it difficult to understand and analyze the execution behavior or to understand the source of a failing execution. This thesis introduces a replay mechanism for Android applications written in Java and is based on the Lamport Clock. This tool provides the user with a controlled debugging environment, where the program execution follows the identical partially ordered happened-before dependency among threads, as during the recorded execution. In this, certain significant events like thread creation, synchronization etc. are recorded during run-time. They can later be replayed off-line, as many times as needed to pinpoint and fix an error in the application. It is software based approach and has been implemented by modifying the Dalvik Virtual Machine in the Android platform. The method of replay described in this thesis is independent of the underlying operating system scheduler. / Dissertation/Thesis / M.S. Computer Science 2011

Eine wichtige Aufgabe bei der Softwareentwicklung ist das Auffinden von Fehlern und das Verstehen ihrer Ursachen. Zur Unterstützung dieser Aufgabe gibt es zahlreiche De-bugger. Bei der Nutzung von Softwaregeneratoren benötigt man zum Debuggen spezielle Informationen. In dieser Arbeit werden Anforderungen an einen Debugger für Software-generatoren definiert. Dazu werden zunächst strukturell ähnliche Softwaregeneratoren auf ihre Debugger untersucht und grundsätzliche Debuggertypen identifiziert. Aus diesen werden 15 Anforderungen formuliert, die der hier beispielhaft betrachtete Softwaregener-ator erfüllen soll. Anschließend erfolgen eine Verallgemeinerung der Ergebnisse und eine kurze Diskussion der Umsetzung auf der Plattform JetBrains MPS.

The goal of this thesis was to design the support for output breakpoints in the Java language and implement the designed solution including integration into the Eclipse IDE. An output breakpoint represents a location in an output media (e.g. file, standard output or socket) where the execution of program should stop. The location in the output media is generalized as a stop condition - it can be in the form of absolute position, a particular line and a character or an occurrence of a text string. The designed solution is based on observing the classes responsible for output using entry method breakpoints that are a standard part of the Java language. This solution is dependent on a particular version and implementation of JRE because some of observed methods are not a part of public Java API.

Continuous advances in VLSI technology have led to more complex digital designs and shrinking transistor sizes. Due to these developments, design verification and manufacturing test have gained more importance and 70 % of the design expenditure in on validation processes. Electronic Design Automation (EDA) tools play a huge role in the validation process with various verification and test tools. Their efficiency have a high impact in saving time and money in this competitive market. Direct Acyclic Graphs (DAGs) are the backbone for most of the EDA tools. DAG is the most efficient data structure to store circuit information and also have efficient backt traversing structure which help in developing reasoning/ debugging tools. In this thesis, we focus on two such EDA tools using graphs as their underlying structure for circuit information storage • Scan pattern Debugger for Partial Scan Designs • Circuit SAT Bounded Model Checkers We developed a complete Interactive Scan Pattern Debugger Suite currently being used in the industry for next generation microprocessor design. The back end is an implication graph based sequential logic simulator which creates a Debug Implication Graph during the logic simulation of the failing patterns. An efficient node traversal mechanism across time frames, in the DIG, is used to perform the root-cause analysis for the failing scan-cells. In addition, the debugger provides visibility into the circuit internals to understand and fix the root-cause. We integrated the proposed technique into the scan ATPG flow for industrial microprocessor designs. We were able to resolve the First Silicon logical pattern failures within hours, which would have otherwise taken a few days of manual effort for root-causing the failure, understanding the root-cause and fixing it. For our circuit SAT implementation, we replace the internal implication graph used by the SAT solver with our debug implication graph (DIG). There is a high amount of circuit unrolling in circuit SAT/ BMC (Bounded Model Checking) problems which creates copies of the same combinational blocks in multiple time frames. This allows us to use the repetitive circuit structure and club it with the CNF database in the SAT solver. We propose a new data structure to store data in a circuit SAT solver which results up to 90% reduction in number of nodes. / Master of Science

abstract: Debugging is a boring, tedious, time consuming but inevitable step of software development and debugging multiple threaded applications with user interactions is even more complicated. Since concurrency and synchronism are normal features in Android mobile applications, the order of thread execution may vary in every run even with the same input. To make things worse, the target erroneous cases may happen just in a few specific runs. Besides, the randomness of user interactions makes the whole debugging procedure more unpredictable. Thus, debugging a multiple threaded application is a tough and challenging task. This thesis introduces a replay mechanism for debugging user interactive multiple threaded Android applications. The approach is based on the 'Lamport Clock' concept, 'Event Driven' implementation and 'Client-Server' architecture. The debugger tool described in this thesis provides a user controlled debugging environment where users or developers are allowed to use modified record application to generate a log file. During the record time, all the necessary events like thread creation, synchronization and user input are recorded. Therefore, based on the information contained in the generated log files, the debugger tool can replay the application off-line since log files provide the deterministic order of execution. In this case, user or developers can replay an application as many times as they need to pinpoint the errors in the applications. / Dissertation/Thesis / M.S. Computer Science 2012

This thesis deals with an introduction to debugging and debuggers. The thesis describes principles of the debugging information, especially the DWARF format and its Call Frame Information (CFI), that enables a debugger to visualize the call stack. Furthermore, extensions of the debugger used in the Lissom project were designed and implemented. These extensions added support for call stack visualization, history value storage and step return and step over commands.