Pretty Printers

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 Codeblocks.

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Test with GDB

• Install a python-enabled GDB. For 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). Below is a sample command file. Replace the path c:/MinGW/share... 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 loaded into GDB's python, which is the purpose of the command file

python
import os, sys
lib_path = os.path.abspath('c:/MinGW/share/gcc-4.7.2/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 the 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

3. Test the printer - example:

(gdb) print words2
$1 = std::vector of length 3, capacity 4 = {"one", "two", "three"}

Add to Codeblocks

Once the command file is correctly loading the python file into GDB, there are two steps to activate in Codeblocks:

1. Set debugger initialization command:
   Codeblocks->Settings->Debugger->Default->Debugger initialization commands

source $(TARGET_COMPILER_DIR)bin\pp.gdb

2. Comment out the Codeblocks gdb handler:

Edit the file (path to Codeblocks)\share\CodeBlocks\scripts\gdb_types.script

Add comments as follows:

    /* 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")
    ); */

Other Info

Links:

GDB Python API

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?