Meaty Skeleton: Difference between revisions

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Preparatory work for a change where I will remove the use of -fbuiltin because it's not safe for use within the system implementation itself.

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Revision as of 13:32, 24 July 2016 (view source) Glauxosdever (talk \| contribs) (Add the link to the Going Further on x86 guide to Meaty Skeleton) ← Older edit		Revision as of 13:29, 1 September 2016 (view source) osdev>Sortie (Preparatory work for a change where I will remove the use of -fbuiltin because it's not safe for use within the system implementation itself.) Newer edit →
Line 152: The special <tt>__is_myos_kernel</tt> macro lets the source code detect whether it is part of the kernel. ~~The kernel is built with <tt>-fbuiltin</tt>, which promises that the C standard~~ ~~functions doesn't do anything unusual. This lets the compiler optimize certain~~ ~~compile-time constant expressions such as <tt>strlen("foo")</tt> to <tt>3</tt>.~~ ~~However, this can have unexpected consequences as a function call can be changed~~ ~~into a call to another function. For instance, GCC likes to rewrite~~ ~~<tt>printf("Hello, World!\n")</tt> into <tt>puts("Hello, World!")</tt>. This is~~ ~~not a terrible problem if you add the needed functions to libk as you need them,~~ ~~or you can simply remove <tt>-fbuiltin</tt> as <tt>-ffreestanding</tt> turns it~~ ~~off by default.~~ == libc and libk Design ==