C++ Bare Bones: Difference between revisions
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m Commented out unused variable to help avoid warning. Also, s/atomic/freestanding/ in the previous change description. :) |
Don't pass controversial option that actually just causes problems, or are redundant. |
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The options for g++ are slightly more numerous than when building a C kernel.
<source lang="bash">i586-elf-g++ -o kmain.o -c kmain.cpp -Wall -Wextra
-nostdlib -fno-
</source>
Note: the flags -Wall -Wextra
Note #2: You may be able to use gcc instead of the i586-elf-gcc from the cross-compiler, but this does not work out of the box on at least Windows and 64-bit linux.
Note #3: The reasons for the disabling of exceptions, RTTI and the stack protector is because they usually require runtime support (which you in a basic kernel don't have). For a more thorough explanation, see the [[C++]] article. There is also an article about the [[GCC_Stack_Smashing_Protector|stack smashing protector]] if you want to enable -fstack-protector.
Note #4: The option -nostdlib is equivalent to passing both -nodefaultlibs and -nostartfiles. You just need to pass -nostdlib.
Note #5: Previous versions of this tutorial suggested passing the -fno-builtin option, but this is actually harmful as you most certainly want compiler builtins (without the __builtin_ prefix) as it lets the compiler understand your code better.
==linker.ld==
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