10_Debugging & Troubleshooting.pdf

PRG 155 – Programming Fundamentals Using C 10. Debugging & Troubleshooting Troubleshooting - Process of identifying and resolving a problem, error or fault within a software or a computer system. ("What is Troubleshooting”) Types of errors: Compilation errors – Errors reported when the code is c...

PRG 155 – Programming Fundamentals Using C 10. Debugging & Troubleshooting Troubleshooting - Process of identifying and resolving a problem, error or fault within a software or a computer system. ("What is Troubleshooting”) Types of errors: Compilation errors – Errors reported when the code is compiled. Compiler warnings  Will not prevent the code from being compiled  Should not be ignored since they often indicate a possible runtime or logic error (not otherwise easy to detect) Compiler errors  Must be fixed for the code to be compiled  Result of syntax errors  Syntax errors - Code does not conform to the syntax of the programming language and the compiler cannot understand it  Examples: extra bracket, missing semicolon  Compiler errors normally include a line number at which the error is found Linker errors - Occur at the linking stage  Indicate that the code compiles but functions/library/global variables that program is using are declared but not defined Logic errors - Cause a wrong program's output/results  Indicate that the code contains some incorrect logic, i.e. "bugs". These errors are completely preventable. Runtime errors - Occur during the execution of the program  Caused by wrong user input, hardware failures, such as a lack of resource (e.g., memory space, disk space, etc.), network connection failure, some mathematical operations (e.g., division by 0, square root of a negative number, etc.). 1 PRG 155 – Programming Fundamentals Using C Debugging  Process of finding and removing computer program errors, called “bugs”.  Errors must be corrected to allow proper program execution. Debugging Techniques ("Debugging with Visual Studio 2005/2008, Part 1: Debugging Concepts"):  Local debugging  Remote debugging  Breakpoints  Trace output  Dump files  Log files References  "What is Troubleshooting? - Definition from Techopedia." Techopedia.com. N.p., n.d. Web. 13 Apr. 2017..  "What is Debugging? - Definition from Techopedia." Techopedia.com. N.p., n.d. Web. 13 Apr. 2017..  "Dealing with Compiler Errors - Surviving the Compilation Process." Dealing with Compiler and Linker Errors - Cprogramming.com. N.p., n.d. Web. 13 Apr. 2017..  "Debugging with Visual Studio 2005/2008, Part 1: Debugging Concepts." Debugging C using Visual Studio 2005/2008: Overview of Debugging Concepts - Cprogramming.com. N.p., n.d. Web. 13 Apr. 2017.. Appendix 1: Using MS Visual Studio - Running & Troubleshooting a Program  To compile a program, click on Build  Build Solution (new program) or Build  Rebuild Solution (program previously compiled)  To run a program continuously (and debug), click on Debug  Start Debugging OR click on (below Tools) 2 PRG 155 – Programming Fundamentals Using C  To run a program one line at the time, click on Debug  Step Into (or F11) and then click on Debug  Step Over (or F10) every time you want to execute one line of the code. Yellow arrow points to the next statement to be executed.  To monitor selected variables while executing a program one line at the time, click on Debug  Windows  Watch  Watch 1 (or 2/3/4). Watch 1 window appears. Move the cursor to Watch 1 window and enter names of variables you want to monitor. NOTE: You have to be in debug mode in order to open the Watch window. The proper sequence is: 1. Step into program (Step Into – F11) 2. Setup Watch window and enter variables to monitor 3. Execute one line at the time (Step Over – F10) while monitoring variables.  To stop executing/debugging a program, click on Debug  Stop Debugging. 3