Pretty Printers

From Code::Blocks
Revision as of 16:22, 25 October 2012 by GravityWe11 (talk | contribs)

GDB Pretty Printers for STL output nicely formatted variables, even for vectors and maps. This works in GDB, and if enabled, in the hover pop-up and watch window in Code::Blocks.


Pprint1.png
UNDER CONSTRUCTION

Step 1 - Test with GDB

  • Install a python-enabled GDB. If you're on Windows, you can install MinGW-Builds over MinGW (consider backing up MinGW first). This updates GCC to 4.7.2 and includes a Python enabled GDB.
  • Create a GDB Command File to enable the printer. Store in c:\mingw\bin\pp.gdb (or wherever you want). Here is a sample command file. Replace the path with your path to printers.py. NOTE: A Python STL printer.py is included with MinGW and MinGW-Builds, so there is no need to download one. It only needs to be turned on, which is the purpose of the command file
python
import os, sys
lib_path = os.path.abspath('c:/MinGW/share/gcc-4.7.0/python/libstdcxx/v6')
sys.path.append(lib_path)
#print 'path is [%s]' % ', '.join(map(str, sys.path))
from printers import register_libstdcxx_printers
register_libstdcxx_printers (None)
end
  • Test
  1. Set a breakpoint in a program and debug
  2. Run GDB command file (can use Codeblocks debugger tab command, or GDB from console) (substitute your path if necessary)
(gdb) source c:\MinGW\bin\pp.gdb
</blockquote>

[li]Test the printer - example:[/li] [code](gdb) print words2 $1 = std::vector of length 3, capacity 4 = {"one", "two", "three"}[/code] [/list] [hr] [u]Step 2 - Add to Codeblocks[/u] Once the printer works in GDB, there are two steps to activate in Codeblocks: [list] [li]Set debugger initialization command settings->debugger->default->debugger initialization commands[/li][/list] [code]source $(TARGET_COMPILER_DIR)bin\pp.gdb[/code] [list][li]Comment out the Codeblocks gdb handler 1) Edit pathto-Codeblocks\share\CodeBlocks\scripts\gdb_types.script 2) Add comments as follows:[/li][/list]

    /* STL String
    driver.RegisterType(
        _T("STL String"),
        _T("[^[:alnum:]_]*string[^[:alnum:]_]*"),
        _T("Evaluate_StlString"),
        _T("Parse_StlString")
    );*/

    /* STL Vector
    driver.RegisterType(
        _T("STL Vector"),
        _T("[^[:alnum:]_]*vector<.*"),
        _T("Evaluate_StlVector"),
        _T("Parse_StlVector")
    ); */

[u]Other Info[/u] Links: http://sourceware.org/gdb/onlinedocs/gdb/Python-API.html http://sourceware.org/gdb/onlinedocs/gdb/Pretty-Printing.html

[u]To Do[/u] 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?

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