Compiler Options

There are a number of compiler flags (for clang and gcc) that tell the compiler to provide more useful information for debugging. Here are a few.

-g

The -g flag tells the compiler to generate debug information, which allows the debugger to find and show you the actual lines of code that are being executed as you're running or stepping through a program. You always want to use the -g flag when you're debugging a problem, but it's also a useful thing to use all the time when writing software, although you probably don't want to use it for production code.

-Og

If you must have some optimization (not likely to be an issue with the code you're writing for classes), the -Og flag tells the compiler to only lightly optimize the code it produces, making it easier to debug, but slightly smaller.

-S

The -S flag goes through all the stages of compiling a program prior to assembling it (i.e., building a .o file). Instead, it leaves you with the generated assembly code. Inspecting the assembly code can tell you how the compiler has interpreted your code for the machine. Using the -S flag alongside various levels of optimization can help you see what the compiler inlines or throws away, which can be helpful if a bug shows up in an optimized binary but not in a non-optimized (or less optimized) build.