Debugging - Revision history

GethinWilliams: /* Testing */

2011-10-31T11:52:44Z

Testing

GethinWilliams: /* Fortran */

2011-03-11T16:04:18Z

Fortran

GethinWilliams: /* Memory Leaks */

2011-03-11T16:03:45Z

Memory Leaks

GethinWilliams: /* Memory Leaks */

2011-03-11T15:52:14Z

Memory Leaks

GethinWilliams: /* =Fortran */

2011-03-11T15:50:20Z

=Fortran

GethinWilliams at 15:38, 11 March 2011

2011-03-11T15:38:57Z

GethinWilliams at 16:01, 5 July 2010

2010-07-05T16:01:35Z

GethinWilliams: /* Debugging Fortran90 Data Structures */

2010-02-15T18:52:49Z

Debugging Fortran90 Data Structures

GethinWilliams: /* Using Emacs as a Debugger */

2010-02-15T18:47:29Z

Using Emacs as a Debugger

GethinWilliams: /* Using Emacs as a Debugger */

2010-02-15T18:46:12Z

Using Emacs as a Debugger

@@ Line 382: / Line 382: @@
 There are few generalities that we can list with regard to testing--different codes are likely to be have rather different needs.  However, I can would stress that it is a good idea to make it as easy as possible to test your code.  Frequent testing is the key to finding bugs quickly and those that are found in a timely manner and far easier to find and fix (1).
-It is possible to add a ''test'' rule to a makefile that you use to compile your code.  Given such a rule and some appropriate scripts, it can be as simple as typing ''make test'' to test your code.  Easy for you.  Easy for your collaborators.  Easier to find and fix the bugs.  To find out more about '''make''' and the addition of a test rule, take a look at [[Make | our course on make]].
+It is possible to add a ''test'' rule to a makefile that you use to compile your code.  Given such a rule and some appropriate scripts, it can be as simple as typing ''make test'' to test your code.  Easy for you.  Easy for your collaborators.  Easier to find and fix the bugs.  To find out more about '''make''' and the addition of a test rule, take a look at our [[Make | course on make]].
 =To go further=

@@ Line 337: / Line 337: @@
 Remember 4-byte reals, <math>50,000 \times 4 = 200,000</math>
-Also:
+If you don't have g95:
 <pre>

← Older revision		Revision as of 16:03, 11 March 2011
Line 336:		Line 336:

	Remember 4-byte reals, <math>50,000 \times 4 = 200,000</math>		Remember 4-byte reals, <math>50,000 \times 4 = 200,000</math>
		+
		+	Also:
		+
		+	<pre>
		+	valgrind --tool=memcheck --leak-check=yes ./memory-leak.exe
		+	</pre>
		+
		+	gives, e.g.
		+
		+	<pre>
		+	...
		+	==20228== HEAP SUMMARY:
		+	==20228== in use at exit: 6,000,000 bytes in 3 blocks
		+	==20228== total heap usage: 9 allocs, 6 frees, 6,025,632 bytes allocated
		+	==20228==
		+	==20228== 2,000,000 bytes in 1 blocks are possibly lost in loss record 1 of 2
		+	==20228== at 0x4A05E1C: malloc (vg_replace_malloc.c:195)
		+	==20228== by 0x307EC1134C: ??? (in /usr/lib64/libgfortran.so.1.0.0)
		+	==20228== by 0x4006CF: MAIN__ (memory-leak.f90:15)
		+	==20228== by 0x40076D: main (in /home/paleo/ggdagw/debugging/examples/example7/memory-leak.exe)
		+	==20228==
		+	==20228== 4,000,000 bytes in 2 blocks are definitely lost in loss record 2 of 2
		+	==20228== at 0x4A05E1C: malloc (vg_replace_malloc.c:195)
		+	==20228== by 0x307EC1134C: ??? (in /usr/lib64/libgfortran.so.1.0.0)
		+	==20228== by 0x4006CF: MAIN__ (memory-leak.f90:15)
		+	==20228== by 0x40076D: main (in /home/paleo/ggdagw/debugging/examples/example7/memory-leak.exe)
		+	==20228==
		+	==20228== LEAK SUMMARY:
		+	==20228== definitely lost: 4,000,000 bytes in 2 blocks
		+	==20228== indirectly lost: 0 bytes in 0 blocks
		+	==20228== possibly lost: 2,000,000 bytes in 1 blocks
		+	==20228== still reachable: 0 bytes in 0 blocks
		+	==20228== suppressed: 0 bytes in 0 blocks
		+	==20228==
		+	==20228== For counts of detected and suppressed errors, rerun with: -v
		+	==20228== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 4 from 4)
		+	</pre>

	==C/C++==		==C/C++==

@@ Line 321: / Line 321: @@
 =Memory Leaks=
 ==Fortran==
 ==C/C++==

@@ Line 322: / Line 322: @@
 =Memory Leaks=
-==Fortran=
+==Fortran==
 ==C/C++==

← Older revision		Revision as of 15:38, 11 March 2011
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	Note that some legacy Fortran code assumes that the value of a variable in a subroutine or function will be retained from one call to the next. This is in contrast to the assumptions of modern programs, where they may be explicitly given the '''save''' attribute if this behaviour is required. A compiler flag may be available to 'save' the variables of a program en masse.		Note that some legacy Fortran code assumes that the value of a variable in a subroutine or function will be retained from one call to the next. This is in contrast to the assumptions of modern programs, where they may be explicitly given the '''save''' attribute if this behaviour is required. A compiler flag may be available to 'save' the variables of a program en masse.
		+
		+	=Memory Leaks=
		+
		+	==Fortran=
		+
		+	==C/C++==

	=Testing=		=Testing=

@@ Line 15: / Line 15: @@
 <pre>
-svn co http://source.ggy.bris.ac.uk/subversion-open/debugging/trunk ./debugging
+svn co https://svn.ggy.bris.ac.uk/subversion-open/debugging/trunk ./debugging
 </pre>

@@ Line 244: / Line 244: @@
 =Debugging Fortran90 Data Structures=
-Previously, '''GDB''' was not able to interpret Fortran90 features such as allocatable arrays and derived types.  This was a pain and meant that in order to fully debug Fortran90 programs, we had to jump through some hoops to enable '''DDD''' to use, for example, the Intel debugger '''IDB'''.  This is no longer the case for some newer Linux distributions, such as CentOS, as here GDB has been patched and works--out-of-the-box--with Fortran90.
+Previously, '''GDB''' was not able to interpret Fortran90 features such as allocatable arrays and derived types.  This was a pain and meant that in order to fully debug Fortran90 programs, we had to jump through some hoops to enable '''DDD''' to use, for example, the Intel debugger '''IDB'''.  This is no longer the case for some newer Linux distributions, such as CentOS 5.4, as here GDB has been patched and works--out-of-the-box--with Fortran90.
 If you would like some example Fortran90 code:

@@ Line 275: / Line 275: @@
 You can run a debugging session through your emacs window, if you like.
-[[Image:Emacs-gdb.JPG|470px|thumbnail|none|Using emacs as a debugger]]
+[[Image:Emacs-gdb.JPG|550px|thumbnail|none|Using emacs as a debugger]]
 =Defensive Programming=

← Older revision		Revision as of 18:46, 15 February 2010
Line 274:		Line 274:

	You can run a debugging session through your emacs window, if you like.		You can run a debugging session through your emacs window, if you like.
		+
		+	[[Image:Emacs-gdb.JPG\|470px\|thumbnail\|none\|Using emacs as a debugger]]

	=Defensive Programming=		=Defensive Programming=