debugging (scott)

7/31/2019 Debugging (Scott)

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Debugging


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I.Definition

Debugging is a methodical process offinding and reducing the number

ofbugs, or defects, in a computer

program or a piece ofelectronichardware, thus making it behave as

expected. Debugging tends to be

harder when various subsystemsare tightly coupled, as changes in one

may cause bugs to emerge in another.
http://en.wikipedia.org/wiki/Computer_bughttp://en.wikipedia.org/wiki/Computer_programhttp://en.wikipedia.org/wiki/Computer_programhttp://en.wikipedia.org/wiki/Electronic_hardwarehttp://en.wikipedia.org/wiki/Electronic_hardwarehttp://en.wikipedia.org/wiki/Low-Coupling_/_High-Cohesion_patternhttp://en.wikipedia.org/wiki/Low-Coupling_/_High-Cohesion_patternhttp://en.wikipedia.org/wiki/Electronic_hardwarehttp://en.wikipedia.org/wiki/Electronic_hardwarehttp://en.wikipedia.org/wiki/Computer_programhttp://en.wikipedia.org/wiki/Computer_programhttp://en.wikipedia.org/wiki/Computer_bug


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II. Origin

The terms "bug" and "debugging" areboth popularly attributed toAdmiral

Grace Hopperin the 1940s. While she

was working on a Mark II Computer atHarvard University, her associates

discovered a moth stuck in a relay and

thereby impeding operation,whereupon she remarked that they

were "debugging" the system.
http://en.wikipedia.org/wiki/Admiral_Grace_Hopperhttp://en.wikipedia.org/wiki/Admiral_Grace_Hopperhttp://en.wikipedia.org/wiki/Admiral_Grace_Hopperhttp://en.wikipedia.org/wiki/Admiral_Grace_Hopper


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The Oxford English Dictionary entryfor "debug" quotes the term

"debugging" used in reference to

airplane engine testing in a 1945article in the Journal of the Royal

Aeronautical Society,

Hopper's bug was found onSeptember 9, 1947.
http://en.wikipedia.org/wiki/Oxford_English_Dictionaryhttp://en.wikipedia.org/wiki/Computer_bughttp://en.wikipedia.org/wiki/Computer_bughttp://en.wikipedia.org/wiki/Oxford_English_Dictionary


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III. Tool

Debuggers are software tools which

enable the programmer to monitor

the execution of a program, stop it, re-start it, set breakpoints, and change

values in memory. The

term debugger can also refer to theperson who is doing the debugging.


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high-level programming languages, such

as Java, make debugging easier,

because they have features suchas exception handling that make real

sources of erratic behaviour easier to

spot. In programming languages suchas C or assembly, bugs may cause silent

problems such as memory corruption,

and it is often difficult to see where the

initial problem happened. In thosecases, memory debugger tools may be

needed.


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In certain situations, general purpose

software tools that are languagespecific in nature can be very useful.These take the form ofstatic codeanalysis tools. These tools look for a

very specific set of known problems,some common and some rare, withinthe source code. All such issuesdetected by these tools would rarelybe picked up by a compiler orinterpreter, thus they are not syntaxcheckers, but more semantic

checkers.
http://en.wikipedia.org/wiki/List_of_tools_for_static_code_analysishttp://en.wikipedia.org/wiki/List_of_tools_for_static_code_analysishttp://en.wikipedia.org/wiki/List_of_tools_for_static_code_analysishttp://en.wikipedia.org/wiki/List_of_tools_for_static_code_analysis


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For debugging electronic hardware

(e.g., computer hardware) as well aslow-level software

(e.g., BIOSes, device drivers)

and firmware, instruments suchasoscilloscopes, logic analyzers orin-

circuit emulators (ICEs) are often

used, alone or in combination. An ICEmay perform many of the typical

software debugger's tasks on low-

level software and firmware.
http://en.wikipedia.org/wiki/Computer_hardwarehttp://en.wikipedia.org/wiki/BIOShttp://en.wikipedia.org/wiki/Device_driverhttp://en.wikipedia.org/wiki/Firmwarehttp://en.wikipedia.org/wiki/Oscilloscopehttp://en.wikipedia.org/wiki/Logic_analyzerhttp://en.wikipedia.org/wiki/In-circuit_emulatorhttp://en.wikipedia.org/wiki/In-circuit_emulatorhttp://en.wikipedia.org/wiki/Softwarehttp://en.wikipedia.org/wiki/Firmwarehttp://en.wikipedia.org/wiki/Firmwarehttp://en.wikipedia.org/wiki/Softwarehttp://en.wikipedia.org/wiki/In-circuit_emulatorhttp://en.wikipedia.org/wiki/In-circuit_emulatorhttp://en.wikipedia.org/wiki/In-circuit_emulatorhttp://en.wikipedia.org/wiki/Logic_analyzerhttp://en.wikipedia.org/wiki/Oscilloscopehttp://en.wikipedia.org/wiki/Firmwarehttp://en.wikipedia.org/wiki/Device_driverhttp://en.wikipedia.org/wiki/BIOShttp://en.wikipedia.org/wiki/Computer_hardware


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IV. Techniques

Print (or tracing) debugging is the actof watching (live or recorded) trace

statements, or print statements, that

indicate the flow of execution of aprocess. This is sometimes

called printf debugging, due to the

use of the printfstatement in C.
http://en.wikipedia.org/wiki/Printfhttp://en.wikipedia.org/wiki/Printf


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Remote debugging is the process ofdebugging a program running on a

system different than the debugger. To

start remote debugging, debuggerconnects to a remote system over a

network. Once connected, debugger

can control the execution of theprogram on the remote system and

retrieve information about its state.


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Post-mortem debugging is debugging ofthe program after it has already crashed.Related techniques often include varioustracing techniques (for example,[8])

and/or analysis ofmemory dump (orcoredump) of the crashed process. Thedump of the process could be obtainedautomatically by the system (forexample, when process has terminateddue to an unhandled exception), or by aprogrammer-inserted instruction, ormanually by the interactive user.
http://en.wikipedia.org/wiki/Crash_(computing)http://en.wikipedia.org/wiki/Debugginghttp://en.wikipedia.org/wiki/Memory_dumphttp://en.wikipedia.org/wiki/Core_dumphttp://en.wikipedia.org/wiki/Core_dumphttp://en.wikipedia.org/wiki/Core_dumphttp://en.wikipedia.org/wiki/Core_dumphttp://en.wikipedia.org/wiki/Memory_dumphttp://en.wikipedia.org/wiki/Debugginghttp://en.wikipedia.org/wiki/Crash_(computing)


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Delta Debugging- technique ofautomating test case simplification.

Saff Squeeze- technique of isolatingfailure within the test using

progressive inlining of parts of the

failing test.[10]
http://en.wikipedia.org/w/index.php?title=Delta_Debugging&action=edit&redlink=1http://en.wikipedia.org/wiki/Debugginghttp://en.wikipedia.org/wiki/Debugginghttp://en.wikipedia.org/w/index.php?title=Delta_Debugging&action=edit&redlink=1


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Thank You!


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