Setting up Debugging Support

All CAPS universe components can deal with three level of debug configuration:

no debug related configure option
--disable-debug configure option
--enable-debug configure option

No Debug related Option

This configuration is called 'passive' here. It is basically the disabled debugging configuration with some exceptions:

symbol DEBUG is defined, symbol NDEBUG isn't defined
all caps_print_debug() messages are still included in the binaries
stack traces are still enabled but mostly useless or empty (my experience)

Attention: If debugging in libcapsbase is disabled, all other components are affected as well and vice versa. It is important to build all components with the same settings.

Disable Debug entirely

When configuring with --disable-debug the following settings are active

code optimization is enabled (autotools default: -O2)
in libraries all internal symbols are hidden
compiler built-ins are enabled
stack traces are disabled
stack protection is enabled
inlining code is enabled
the FORTIFY_SOURCE feature is enabled
all caps_print_debug() messages are removed from the binaries
debug symbols are still kept in the binaries
symbol NDEBUG is defined, symbol DEBUG isn't defined

With this configuration you still can use gdb to trace your program. But my experience is, its hard to do so.

Enable full Debug

code optimization is disabled (-O0 or if supported by the compiler: -Og)
in libraries all internal symbols are externally visible
compiler built-ins are disabled
stack traces are enabled
stack protection is disabled
inlining code is disabled
unwind tables are enabled to have meaningful stack traces
the FORTIFY_SOURCE feature is disabled
all caps_print_debug() messages are included in the binaries
debug symbols are available in the binaries
symbol DEBUG is defined, symbol NDEBUG isn't defined

With this configuration you can use gdb to trace your program in a useful manner. Stack traces are meaningful and thus, helpful as well.

Refer CAPS universe early verbosity setup as well

Overwriting settings

As intended by the autotools, you can add your own flags be defining the environment variables CPPFLAGS, CFLAGS, LDFLAGS and LIBS when configuring the package.

The variables content is always appended to the settings. With this feature you can still overwrite these settings as needed.

There is one exception: The -O2 optimization gets always removed if debugging is enabled.