Code::Blocks - User contributions [en]

Pretty Printers

2014-02-01T09:49:59Z

RobinWhittle: Previous fix wasn't enough - replaced the entire Linux download URL

[[Category: User Documentation]]
GDB Pretty Printers for STL display nicely formatted variables in the hover pop-up and watch window, for all STL containers (vectors, maps, etc).
----
[[File:Pprint1.png|border|Popup example]] 
==Test with GDB==

*Ensure GDB is python-enabled. For Linux (tested with recent Ubuntu), it is enabled by default. For Windows, MinGW's GDB is not python enabled. One option is to install [http://sourceforge.net/projects/mingwbuilds/ MinGW-Builds] over MinGW (consider backing up MinGW first). This updates GCC to 4.7.2 and includes a Python enabled GDB.
<ol>
To test, launch GDB from console:
<pre>
(gdb) python print sys.version
</pre>
If python is enabled, the version will be printed (probably 2.7.x), otherwise, a message will indicate python scripting is not supported.
</ol>
*Download printers.py (if necessary)
:Windows users with MinGW should already have this file in /MinGW/share/gcc-4.7.2/python/libstdcxx/v6.
:Linux users can download printers.py [http://gcc.gnu.org/svn/gcc/trunk/libstdc++-v3/python/libstdcxx/v6/printers.py here]. Save as <tt>/home/username/gdb_printers/printers.py</tt>.
*Create a GDB [http://sourceware.org/gdb/onlinedocs/gdb/Command-Files.html Command File] to enable the printer. Store in <tt>c:\mingw\bin\pp.gdb</tt> (windows) or <tt>/home/username/gdb_printers/pp.gdb</tt> (linux). Below is a sample command file. Replace the path c:/MinGW/share... with your path to printers.py.
<blockquote><pre>
python
import sys
sys.path.insert(0, 'c:/MinGW/share/gcc-4.7.2/python/libstdcxx/v6')
from printers import register_libstdcxx_printers
register_libstdcxx_printers (None)
end
</pre></blockquote>
*Test
#Set a breakpoint in a program and debug
#Run the command file from GDB (can use Codeblocks->debugger tab->command, or in GDB from the console) (substitute your path if necessary)
<ol><pre>(gdb) source c:\MinGW\bin\pp.gdb</pre></ol>
<ol start="3">
<li>Test the printer - example:</li>
</ol>
<ol><pre>(gdb) print words2
$1 = std::vector of length 3, capacity 4 = {"one", "two", "three"}
</pre></ol>

==Add to Codeblocks==
Once the command file is working correctly, there are two steps to activate in Codeblocks:
#Set debugger initialization command (substitute your path as necessary): <tt>Codeblocks->Settings->Debugger->Default->Debugger initialization commands</tt>
<ol><pre>source c:\MinGW\bin\pp.gdb</pre>
NOTE: A bug in the Linux version of Codeblocks may prevent entering anything in the Debugger Initialization Commands field. A work-around is to open a CBP project file via a file manager, which in turn launches Codeblocks and seems to resolve the issue.
</ol>
<ol start="2">
<li>Disable Codeblocks handling of watch values:</li>
</ol>
<ol><tt>Codeblocks->Settings->Debugger->Default->Enable Watch Scripts = Unchecked</tt></ol>
===Other Info===
Links:

[http://sourceware.org/gdb/onlinedocs/gdb/Python-API.html GDB Python API]

[http://sourceware.org/gdb/onlinedocs/gdb/Pretty-Printing.html GDB Pretty Printing]

===To Do===
The third column in the Codeblocks popup and watch window displays a long unformatted string. Codeblocks is calling the GDB whatis command. Can this command be Pretty-Printed?

==See also==
* [[Debugging with Code::Blocks]]
* [[Debugger scripts]]

Pretty Printers

2014-02-01T09:48:22Z

RobinWhittle: /* Test with GDB */ Replaced "viewcvs" with "svn" in Linux download URL

[[Category: User Documentation]]
GDB Pretty Printers for STL display nicely formatted variables in the hover pop-up and watch window, for all STL containers (vectors, maps, etc).
----
[[File:Pprint1.png|border|Popup example]] 
==Test with GDB==

*Ensure GDB is python-enabled. For Linux (tested with recent Ubuntu), it is enabled by default. For Windows, MinGW's GDB is not python enabled. One option is to install [http://sourceforge.net/projects/mingwbuilds/ MinGW-Builds] over MinGW (consider backing up MinGW first). This updates GCC to 4.7.2 and includes a Python enabled GDB.
<ol>
To test, launch GDB from console:
<pre>
(gdb) python print sys.version
</pre>
If python is enabled, the version will be printed (probably 2.7.x), otherwise, a message will indicate python scripting is not supported.
</ol>
*Download printers.py (if necessary)
:Windows users with MinGW should already have this file in /MinGW/share/gcc-4.7.2/python/libstdcxx/v6.
:Linux users can download printers.py [http://gcc.gnu.org/svn/trunk/libstdc%2B%2B-v3/python/libstdcxx/v6/ here]. Save as <tt>/home/username/gdb_printers/printers.py</tt>.
*Create a GDB [http://sourceware.org/gdb/onlinedocs/gdb/Command-Files.html Command File] to enable the printer. Store in <tt>c:\mingw\bin\pp.gdb</tt> (windows) or <tt>/home/username/gdb_printers/pp.gdb</tt> (linux). Below is a sample command file. Replace the path c:/MinGW/share... with your path to printers.py.
<blockquote><pre>
python
import sys
sys.path.insert(0, 'c:/MinGW/share/gcc-4.7.2/python/libstdcxx/v6')
from printers import register_libstdcxx_printers
register_libstdcxx_printers (None)
end
</pre></blockquote>
*Test
#Set a breakpoint in a program and debug
#Run the command file from GDB (can use Codeblocks->debugger tab->command, or in GDB from the console) (substitute your path if necessary)
<ol><pre>(gdb) source c:\MinGW\bin\pp.gdb</pre></ol>
<ol start="3">
<li>Test the printer - example:</li>
</ol>
<ol><pre>(gdb) print words2
$1 = std::vector of length 3, capacity 4 = {"one", "two", "three"}
</pre></ol>

==Add to Codeblocks==
Once the command file is working correctly, there are two steps to activate in Codeblocks:
#Set debugger initialization command (substitute your path as necessary): <tt>Codeblocks->Settings->Debugger->Default->Debugger initialization commands</tt>
<ol><pre>source c:\MinGW\bin\pp.gdb</pre>
NOTE: A bug in the Linux version of Codeblocks may prevent entering anything in the Debugger Initialization Commands field. A work-around is to open a CBP project file via a file manager, which in turn launches Codeblocks and seems to resolve the issue.
</ol>
<ol start="2">
<li>Disable Codeblocks handling of watch values:</li>
</ol>
<ol><tt>Codeblocks->Settings->Debugger->Default->Enable Watch Scripts = Unchecked</tt></ol>
===Other Info===
Links:

[http://sourceware.org/gdb/onlinedocs/gdb/Python-API.html GDB Python API]

[http://sourceware.org/gdb/onlinedocs/gdb/Pretty-Printing.html GDB Pretty Printing]

===To Do===
The third column in the Codeblocks popup and watch window displays a long unformatted string. Codeblocks is calling the GDB whatis command. Can this command be Pretty-Printed?

==See also==
* [[Debugging with Code::Blocks]]
* [[Debugger scripts]]