Cpp debug - Revision history

T1t0: /* See also */

2021-03-14T00:42:01Z

imported>T1t0 at 01:02, 7 January 2019

2019-01-07T01:02:33Z

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	</pre>		</pre>

			= See also =

			[[Profiling]]

			[[Category:cpp]]
	[[Category:debug]]		[[Category:debug]]
	~~[[Category:cpp]]~~
	[[Category:to_translate]]		[[Category:to_translate]]

imported>T1t0 at 01:50, 8 July 2018

2018-07-08T01:50:28Z

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	[[Category:debug]]		[[Category:debug]]
	[[Category:cpp]]		[[Category:cpp]]
			[[Category:to_translate]]

imported>T1t0 at 01:59, 3 July 2018

2018-07-03T01:59:32Z

← Older revision		Revision as of 01:59, 3 July 2018
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	<pre>		<pre>
	On Nov 6, 10:~~44 am~~, t1t0 <t...@noemail.not> wrote:		On Nov 6, 10:44 am, t1t0 <t...@noemail.not> wrote:
	> On Sun, 06 Nov 2011 01:15:05 +0000, Kaz Kylheku wrote:		> On Sun, 06 Nov 2011 01:15:05 +0000, Kaz Kylheku wrote:

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	to turn this into text.		to turn this into text.

	> > I wrote a crash dump reporter on Windows CE quite a few years ago. It		> > I wrote a crash dump reporter on Windows CE quite a few years ago. It
	> > was very helpful, because crashing programs would just "disappear		> > was very helpful, because crashing programs would just "disappear
	> > without a trace" on that platform		> > without a trace" on that platform
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	</pre>		</pre>

	~~----~~		= GDB =

	=== GDB ===

	<pre>		<pre>
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	- http://sourceware.org/gdb/current/onlinedocs/gdb/TUI.html		- http://sourceware.org/gdb/current/onlinedocs/gdb/TUI.html

	~~----~~		= libSegFault.so =

	=== libSegFault.so ===

	from http://groleo.wordpress.com/2010/05/04/when-you-cant-use-gdb-or-valgrind-there-is-liblibsegfault-so/		from http://groleo.wordpress.com/2010/05/04/when-you-cant-use-gdb-or-valgrind-there-is-liblibsegfault-so/
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	For more details, see [[linux_LD_PRELOAD]]		For more details, see [[linux_LD_PRELOAD]]

	~~----~~		= Get human readable signal message =

	=== Get human readable signal message ===

	<pre>		<pre>
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	}		}
	</pre>		</pre>

	~~----~~

	[[Category:debug]]		[[Category:debug]]
	[[Category:cpp]]		[[Category:cpp]]

imported>T1t0 at 02:23, 3 September 2016

2016-09-03T02:23:33Z

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	</pre>		</pre>

			----

			=== GDB ===

			<pre>
			gcc -g -O0 src/main.c -o ./main # compile with debug info and without optimization
			ulimit -c unlimited # enable core dump
			objdump --syms ./main \| less # test debug symbols existance
			./main # run the program with a fatal error, producing a core archive e.g. core.27133
			gdb -tui ./main -c ./core.27133 -d ./src # run the debuger
			bt full # see the full callstack
			</pre>

			For more GDB commands, see [https://people.eecs.berkeley.edu/~mavam/teaching/cs161-sp11/gdb-refcard.pdf GDB quick reference card, version 5].

	----		* from

			- http://stackoverflow.com/a/22711917

			- http://stackoverflow.com/a/22711917

			- http://sourceware.org/gdb/current/onlinedocs/gdb/TUI.html

			----

	=== libSegFault.so ===		=== libSegFault.so ===

imported>T1t0: /* libSegFault.so */

2016-08-31T02:23:14Z

libSegFault.so

← Older revision		Revision as of 02:23, 31 August 2016
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	Thats it .		Thats it .
	</pre>		</pre>

			For more details, see [[linux_LD_PRELOAD]]

	----		----

imported>T1t0 at 14:34, 30 August 2016

2016-08-30T14:34:15Z

@@ Line 110: / Line 110: @@
 </pre>
 [[Category:debug]]
 [[Category:cpp]]

imported>T1t0 at 15:10, 6 February 2012

2012-02-06T15:10:23Z

@@ Line 33: / Line 33: @@
 Windows minidumps is that they're a bit too limited.
 </pre>
 Una soluzione quasi ideale sarebbe creare un Guardian, ovvero un programma minimale (confidabile, che non abbia errori) che preparerebbe l'ambiente e inizierebbe l'applicazione e in caso di crash invierebbe un email con il crashdump e reinizierebbe l'applicazione di nuovo.

imported>T1t0 at 14:26, 6 February 2012

2012-02-06T14:26:52Z

← Older revision		Revision as of 14:26, 6 February 2012
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			Il programma DDD é un'alternativa decente a gdb senza perderne funzionalità utili e simili a quelle disponibili nel debugger di VisualStudio. Il problema é che cose come divisione per zero non generano exceptions in Linux, ma segnali che possono essere catturati con strumenti più 'antichi' e che non garantiscono che il programma continui normalmente.

			Il problema fondamentale non é la divisione per zero, ma che un programmatore non ha testato questa eventualità e scelto cosa fare (in questo caso ha perfettamente senso che il programma non continui!). In queste situazioni è necessario che il programma segnali il problema prima di terminare, in questo modo il programmatore potrá individuare e correggere il problema.

			Quello che si potrebbe fare è generare un dump della memoria e analizzarlo. In Linux è semplice ottenere il dump, è necessario indicare <pre>
			ulimit -c unlimited </pre> prima di eseguire il programma.

			Per Windows dovrebbe esserci uno strumento simile. Quello che segue é un estratto di una discussione su Usenet:

			<pre>
			On Nov 6, 10:44 am, t1t0 <t...@noemail.not> wrote:
			> On Sun, 06 Nov 2011 01:15:05 +0000, Kaz Kylheku wrote:

			> > You can catch an exception (in every thread) and then use the API to
			> > list the modules, snapshot the thread state and such.
			>
			> But what about signal error (like zero division)? Did Windows produce a
			> signal error or a exception for this kind of error?

			yes divide by zero generates on exception on Windows. There are ways
			to turn this into text.

			> > I wrote a crash dump reporter on Windows CE quite a few years ago. It
			> > was very helpful, because crashing programs would just "disappear
			> > without a trace" on that platform
			>
			> Nice, this is exactly what I want to avoid at all costs: the death of the
			> application without trace!
			> So, on Windows there is an API to create a core dump, or is it a 'manual'
			> implementation ?

			search MSDN. I found MiniDumpWriteDump(),though my experience of
			Windows minidumps is that they're a bit too limited.
			</pre>

			Una soluzione quasi ideale sarebbe creare un Guardian, ovvero un programma minimale (confidabile, che non abbia errori) che preparerebbe l'ambiente e inizierebbe l'applicazione e in caso di crash invierebbe un email con il crashdump e reinizierebbe l'applicazione di nuovo.

			Resta il fatto che per ottenere informazioni utili dal coredump, il programma dovrebbe essere compilato con le informazioni di debug, cosa che permetterebbe di ottenerne il codice sorgente. Una soluzione in Linux é compilare con le informazioni di debug e usare in produzione una copia 'pulita' con il comando strip:

			from http://stackoverflow.com/questions/2251391/core-dump-in-linux
			<pre>
			The usual solution is to build with -g and to strip off the debug information before releasing the file.
			Look for the 'strip' command. You keep the file with debug information and use it to debug core dumps you get from customers.
			</pre>

			from http://sourceware.org/gdb/current/onlinedocs/gdb/Separate-Debug-Files.html
			<pre>
			gdb allows you to put a program's debugging information in a file separate from the executable itself,
			in a way that allows gdb to find and load the debugging information automatically.
			[...]
			The gnu binary utilities (Binutils) package includes the `objcopy' utility that can produce
			the separated executable / debugging information file pairs using the following commands:
			objcopy --only-keep-debug foo foo.debug
			strip -g foo
			</pre>



			----



	=== libSegFault.so ===		=== libSegFault.so ===

imported>T1t0 at 12:32, 6 February 2012

2012-02-06T12:32:55Z

← Older revision		Revision as of 12:32, 6 February 2012
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	[[Category:debug]]		[[Category:debug]]
			[[Category:cpp]]

← Older revision		Revision as of 00:42, 14 March 2021
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	[[Profiling]]		[[Profiling]]

	[[Category:cpp]]		[[Category:develop]]
			[[Category:c/cpp]]
	[[Category:debug]]		[[Category:debug]]
	[[Category:to_translate]]		[[Category:to_translate]]