Configuring Mudflap to find errors

To use Mudflap in the IDE, you need to define Mudflap options to add the right flag to the compiler command for your application. There is a runtime library, libmudflap, that gets attached to the application process and is controlled by runtime options that are automatically set in the MUDFLAP_OPTIONS environment variable. This variable is set when the Mudflap tool is added to the launch configuration; the Mudflap options are also set there.

The instrumentation relies on this separate runtime library. Note that both QNX and Managed projects use the -fmudflapth option for the compiler and linker because this option supports threads (-fmudflap doesn't work with multithreaded programs).

To configure Mudflap to find errors in your code:

Instrument the binary with Mudflap, by doing the following steps:
For a QNX project:
1. In the Project Explorer, right-click a project and select Properties.
2. On the left, select QNX C/C++ Project to open the properties page.
3. On the Options tab, check the Build with Mudflap box.
4. Click OK.
5. Rebuild the project (File > Build Project).
For a Managed Project with a QNX toolchain:
1. In the Project Explorer, right-click a project and select Properties.
2. On the left, select C/C++ Build, then Settings to open the properties page.
3. On the Tool Settings tab, expand QCC Compiler, then select Output Control.
4. In the configuration options on the right, check the Build with Mudflap box.
5. On the Tool Settings tab, expand QCC Linker, then select Output Control.
6. In the configuration options on the right, check the Build with Mudflap box.
7. Click OK.
8. Rebuild the project (File > Build Project).
To launch the instrumented binary with Mudflap enabled, do these steps:
1. Open the project's launch configuration by selecting Run As > Run Configurations.
2. Select the Tools tab, then click Add/Delete Tool.
3. In the Tools selection dialog, check the Mudflap box and click OK.
  The IDE displays the Mudflap tab in the launch configuration.
4. Configure any desired Mudflap options.
  
  Enable Mudflapping
  
  Enables the Mudflap feature to check for errors. Mudflap adds extra code to the compiled program to check for buffer overruns, which slows a program's performance (and at build time, the compiler needs to process the instrumentation code). So you should only use Mudflap during testing, and disable it in your production version.
  
  Output File
  
  Specify the location for the Mudflap output log file. Click Workspace… to specify a location in your workspace, or Filesystem… to specify a location your filesystem.
  
  Do not print read access violations
  
  Read access violations are not recorded. The Mudflap option for this feature is -ignore-reads.
  
  Print memory leaks at program exit
  
  When the program shuts down, print a list of memory objects on the heap that have not been deallocated. The Mudflap option for this feature is -print-leaks.
  
  Enabled memory violation protection
  
  Trigger a violation for every main call. This option is useful as a debugging aid. The Mudflap option for this feature is -mode-violate.
  
  Perform more expensive internal checking
  
  Periodically traverse the internal structures to assert the absence of corruption. The Mudflap option for this feature is -internal-checking.
  
  Detect uninitialized object reads
  
  Verify that the memory objects on the heap have been written to before they are read. The Mudflap option for this feature is -check-initialization.
  
  Print report upon SIGUSR1
  
  Handle signal SIGUSR1 by printing the similar report that will be printed at shutdown. This option is useful for monitoring interactions of a long running program. The Mudflap option for this feature is -sigusr1-report.
  
  Wipe stack objects at unwind
  
  Clear each tracked stack object when it goes out of scope. This options is useful as a security or debugging measure. The Mudflap option for this feature is -wipe-stack.
  
  Wipe heap objects at free
  
  Clear each tracked heap object being deallocated when it goes out of scope. This option is useful as a security or debugging measure. The Mudflap option for this feature is -wipe-heap.
  
  Action when violation found
  
  Select a specific action for Mudflap to take when it encounters a violation.
  violations do not change program execution — Violations don't change the program execution. This means that this option will do nothing and the program may continue with the erroneous access; however, this action may corrupt its own state, or the state of libmudflap. The Mudflap option for this feature is -viol-nop.
  
  violations cause a call to abort() — A call is made to the abort function when a violation is encountered, which then requests a core dump and exit. The Mudflap option for this feature is -viol-abort.
  
  violations are promoted to SIGSEGV signals — Generate a SIGSEGV, which a program may choose to catch. The Mudflap option for this feature is -viol-segv.
  
  Keep an N-level stack trace of each call context
  
  Record N levels of tack backtrace information for each allocation, deallocation, and violation. The Mudflap option for this feature is -backtrace=N.
  
  Other Mudflap options (space separated)
  
  A field where you can specify additional Mudflap options. For information about these options, see Options for Mudflap below.
Click Run or Debug to launch the application.

The Mudflap session opens and shows the Mudflap Violation view. This view contains any errors that the tool encounters; the errors are recorded in the Mudflap log file and visually presented by the IDE. You can select an error from the list to navigate to the location of that error in the source code.