Patent Application
20090199163
Exemplary embodiments of the present invention relate to software debugging environments, and more particularly, to searching execution state data within a software debugging environment.
Software development tools are software applications that enable a software developer to write software applications. Certain tools, for instance, can be employed to aid in understanding program behavior, an important aspect of software development. Such an understanding can ensure that a program being developed will operate as expected and correctly interact with external libraries and frameworks. Examples of tools that can be employed to gain an understanding of program behavior include tracing tools for tracing execution of a program and debugger tools that enable inspection and testing of the behavior of running programs.
Many software developers find it convenient to utilize a single umbrella application, known as an integrated development environment (IDE) such as Eclipse or Microsoft Visual Studio, that includes several software development tools. A typical IDE provides an environment incorporating tools for source code editing, compiling, linking, testing, debugging, and profiling. By presenting a single program in which all or much of the development can be done, an IDE environment can enhance the value of each individual tool (for example, a debugger) by having it integrate seamlessly with the other development tools included in the IDE. The advantage of using an IDE is that the software developer need not be concerned about the tool interfaces when moving from one phase of code development to the other.
As mentioned, the functions that are incorporated into the tools of an IDE may include debugging and tracing, profiling, and logging. Debugging is used to locate and identify errors in a computer program under development. Some debuggers provide the ability to modify the state of the program while it is running, rather than to merely observe it. Tracing is used to print the values of the variables and identify the conditions at a particular statement.
“Step” functions and breakpoint operations are two primary operations that are supported by conventional debuggers to assist a software developer in acquiring knowledge about a program during its execution. A step function permits statements in a computer program to be executed one at a time and displays the results of each instruction upon completion. While the step operation provides a programmer with a large amount of information about a program during its execution, the task of stepping through hundreds or thousands of program instructions may be tedious and time consuming. A breakpoint operation permits a computer programmer to intentionally halt the execution of a computer program at a precise instruction.
Used together, step operations and breakpoints can simplify the debugging process. A computer program executes normally by a debugger until a breakpoint is reached, at which point the program stops execution and the debugger displays various aspects of the program state, such as the call stack and the contents of memory, to the programmer for analysis. The programmer can then step through the code line-by-line using the step operation. The programmer is thus able to isolate and analyze a particular set of instructions without having to step through irrelevant portions of a computer program.
A limitation of existing debuggers for inspecting memory state is that program variables are presented by their name, which may require that the programmer have detailed symbolic information regarding all of the relevant data types, variables, and so on to be able discover the contents and structure of the data within a program invocation. This can become problematic in situations where data structures are complex and deeply nested, particularly when the data structures in question belong to a predefined library or framework that was authored by someone other than the programmer performing the debugging. In these situations, when a programmer encounters a debugging problem in executing a software program, part of the debugging task can involve time-intensive “hunting” for the desired variable or field, as there can be many variables in the current context of a running program. In particular, finding a particular value (such as a given string or number) may be hard to do. The typical solution is to manually traverse the set of variables and repeatedly access the sub-structures of data structures to reveal nested data. This can be time consuming and frustrating, and is impractical for large data structures containing thousands or millions of nodes.
Related work in the literature includes systems that enhance the debugger with interactive commands to search and display complex data structures. For example, the “Duel” system (USENIX 1993 paper, available at http://citeseer.ist.psu.edu/golan93duel.html) extends the GNU debugger, GDB, with support for such scripting language commands. Among the features of the Duel scripting language is the ability to find values within arrays and data structures specified by the developer. A significant limitation of this approach is that the developer needs knowledge of the data structures in order to specify where to search for a given value, which reduces the value of the debugger as a program understanding tool. Another disadvantage is that each query so formed is bound to a specific arrangement of data structures. That is, it will find matching values within a particular field of a particular data type, but will not find matches within other fields of other data types. Yet another disadvantage is the need to master an additional language, that is, the scripting language.
The shortcomings of the prior art can be overcome and additional advantages can be provided through exemplary embodiments of the present invention that are related to a software module for searching within a software debugging environment. The software module comprises a search component and an interface component. The search component is configured to be implemented within a debugging tool configured to access a set of execution state data for a program being monitored by the debugging tool when execution of the program is stopped. The search component is configured to search the set of execution state data to locate instances of a particular value. The interface component is configured to allow a user to specify the particular value in a search query, submit the search query to the search component, and present a description of each instance of the particular value located by the search component to the user.
The shortcomings of the prior art can also be overcome and additional advantages can also be provided through exemplary embodiments of the present invention that are related to methods, computer program products, and data processing systems corresponding to the above-summarized module are also described herein.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
As a result of exemplary embodiments of the summarized invention, technically we have achieved a solution that can be implemented within a software debugging environment to improve tool support for program understanding by providing a search mechanism enabling a programmer to locate instances of data by value, rather than by its symbolic attachment to known variables.
The subject matter that is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description of exemplary embodiments of the present invention taken in conjunction with the accompanying drawings in which:
The detailed description explains exemplary embodiments of the present invention, together with advantages and features, by way of example with reference to the drawings. The flow diagrams depicted herein are just examples. There may be many variations to these diagrams or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified. All of these variations are considered a part of the claimed invention.
While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the description of exemplary embodiments in conjunction with the drawings. It is of course to be understood that the embodiments described herein are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed in relation to the exemplary embodiments described herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriate form. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the invention.
A typical debugging tool executes as a self-contained process for controlling an application program under study by using operating system primitives designed for that purpose. Debuggers are commonly used for examining the execution state or context of running program, which can include, for example, the call stack and the current state of variables, registers, and storage. In particular, a debugger can enable a developer to intentionally stop or pause a running program at a breakpoint and inspect the execution state (logs, memory, files, etc.) in the test environment to determine whether the program functions as expected. In general, a breakpoint can consist of one or more conditions that determine when a program's execution should be interrupted. Breakpoints can be set by a developer so that program execution halts, for example, when a specific line number or instruction is reached, upon entry to a specific function, at a specific time, when a specific module is loaded, upon a specific keystroke, and when a specific location in storage is read from, written to, or modified.
Debugging tools are commonly implemented with a command line interface (CLI), a textual user interface (TUI), or a graphical user interface (GUI). A GUI debugger typically provides a window in which a list of variables and their respective values are displayed in a frame during the operation of the debugger. As an example of such a debugging window,
As demonstrated by
Exemplary embodiments of the present invention can be implemented as a search module providing an interface within a software debugging environment by providing the following components: (1) A user interface for specifying the value or values for which to search (as well as, in exemplary embodiments, other search parameters); (2) a module configured to perform the search for the specified values within the data accessible to the program at a given moment in the program's execution; and (3) a user interface for displaying the search results. In exemplary embodiments in which the debugging tool is provided within a GUI (for instance, as a GUI interface provided by an IDE; for example, an exemplary embodiment could be implemented by the Standard Widget Toolkit provided by Eclipse), then the above components could be incorporated into the GUI and made accessible using widgets. For example, the user interface for specifying the search could be implemented in a text or dialog box and the search results can be displayed in a viewer window or in a child window. In exemplary embodiments in which the debugging tool is provided within a TUI (for instance, the GNU Debugger (GDB)), the above components could be incorporated using the available text and symbols provided by the interface. In exemplary embodiments in which the debugging tool is provided within a CLI, the above components could be incorporated into the CLI as functionality that be accessed using syntax and semantics that can be entered in the command line shell and configured to present search results in the text interface.
Referring now to
In the present exemplary process, at block 204, the developer accesses the interface provided by the search module to enter a search query for a particular value of interest and submits the search to the search module. At block 205, the search module runs the search on the accessible data acquired at block 203. In exemplary embodiments, the search module can perform the search by scanning the current program context and recursively examining data structures as needed. In implementing the search module, care can be taken to avoid infinite loops that could occur in the presence of cycles (such as might occur in the case of data structures with both “parent” and “child” pointers). At block 206, the search results are presented to the developer by the interface provided by the search module in some fashion. In exemplary embodiments, the search interface may be implemented so as to provide the developer with the option to, at decision block 207, perform additional searches for values of interest, in which case the process returns to block 204 to accept a new search query from the developer. At block 208, after the developer has completed any desired searching, execution of the program can be resumed, and the process returns to block 201 until the program terminates. It should be noted that while the process illustrated in
Referring now to
In the present exemplary process, with execution of the program stopped or paused, the developer is provided with the option to perform any of the various debugging actions provided by the IDE. At block 305, the developer chooses to perform a search for a particular value of interest and thus invokes the GUI search query component (for example, a widget such as a search query dialog box) provided by the search module implemented within the IDE. At block 306, the developer submits a search query for the value of interest to the search module.
Referring back to exemplary process depicted in
As one alternative to the non-limiting example illustrated in
Exemplary embodiments of the present invention can be configured to be implemented within any software debugging environment. Exemplary embodiments can be implemented as an aspect of a software package for a debugging tool, or as a software module or component implemented for incorporation with a debugging tool as, for example, one or more libraries of functions, one or more plug-in or extension modules, one or more dynamic link-libraries, etc.
Exemplary embodiments of the present invention can be realized in hardware, software, or a combination of hardware and software. Exemplary embodiments can be realized in a centralized fashion in one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system—or other apparatus adapted for carrying out the methods described herein—is suited. A typical combination of hardware and software could be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.
Exemplary embodiments of the present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which—when loaded in a computer system—is able to carry out these methods. Computer program means or computer program as used in the present invention indicates any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or, notation; and b) reproduction in a different material form.
A computer system in which exemplary embodiments can be implemented may include, inter alia, one or more computers and at least a computer program product on a computer readable medium, allowing a computer system, to read data, instructions, messages or message packets, and other computer readable information from the computer readable medium. The computer readable medium may include non-volatile memory, such as ROM, Flash memory, Disk drive memory, CD-ROM, and other permanent storage. Additionally, a computer readable medium may include, for example, volatile storage such as RAM, buffers, cache memory, and network circuits. Furthermore, the computer readable medium may comprise computer readable information in a transitory state medium such as a network link and/or a network interface, including a wired network or a wireless network, that allow a computer system to read such computer readable information.
Although exemplary embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions and alternations could be made thereto without departing from spirit and scope of the inventions as defined by the appended claims. Variations described for exemplary embodiments of the present invention can be realized in any combination desirable for each particular application. Thus particular limitations, and/or embodiment enhancements described herein, which may have particular advantages to a particular application, need not be used for all applications. Also, not all limitations need be implemented in methods, systems, and/or apparatuses including one or more concepts described with relation to exemplary embodiments of the present invention.
While exemplary embodiments of the present invention have been described, it will be understood that those skilled in the art, both now and in the future, may make various modifications without departing from the spirit and the scope of the present invention as set forth in the following claims. These following claims should be construed to maintain the proper protection for the present invention.
