Difference between revisions of "Pretty Printers"

From Code::Blocks
Line 18: Line 18:
 
*Test
 
*Test
 
#Set a breakpoint in a program and debug
 
#Set a breakpoint in a program and debug
#Run GDB command file (can use Codeblocks debugger tab command, or GDB from console) (substitute your path if necessary)
+
#Run the GDB command file (can use Codeblocks debugger tab command, or GDB from console) (substitute your path if necessary)
 
<ol><span style="font-size: 10pt"><pre>(gdb) source c:\MinGW\bin\pp.gdb</pre></span></ol>
 
<ol><span style="font-size: 10pt"><pre>(gdb) source c:\MinGW\bin\pp.gdb</pre></span></ol>
 
<ol start="3">
 
<ol start="3">

Revision as of 19:42, 25 October 2012

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.


Popup example

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
  1. Test the printer - example:
    (gdb) print words2
    $1 = std::vector of length 3, capacity 4 = {"one", "two", "three"}
    

Add to Codeblocks

Once the printer works in 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
  1. 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?