path: root/src/include/sys
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2019-02-22add membarrier syscall wrapper, refactor dynamic tls install to use itRich Felker-0/+9
the motivation for this change is twofold. first, it gets the fallback logic out of the dynamic linker, improving code readability and organization. second, it provides application code that wants to use the membarrier syscall, which depends on preregistration of intent before the process becomes multithreaded unless unbounded latency is acceptable, with a symbol that, when linked, ensures that this registration happens.
2018-12-09add namespace-safe version of getauxval for internal useRich Felker-0/+10
2018-09-12use wrapper headers to hide most namespaced/internally-public symbolsRich Felker-12/+13
not all prefixed symbols can be made hidden. some are part of ABI-compat (e.g. __nl_langinfo_l) and others are ABI as a consequence of the way copy relocations for weak aliases work in ELF shared libraries. most, however, can be made hidden. with this commit, there should be no remaining unintentionally visible symbols exported from
2018-09-12overhaul internally-public declarations using wrapper headersRich Felker-0/+36
commits leading up to this one have moved the vast majority of libc-internal interface declarations to appropriate internal headers, allowing them to be type-checked and setting the stage to limit their visibility. the ones that have not yet been moved are mostly namespace-protected aliases for standard/public interfaces, which exist to facilitate implementing plain C functions in terms of POSIX functionality, or C or POSIX functionality in terms of extensions that are not standardized. some don't quite fit this description, but are "internally public" interfacs between subsystems of libc. rather than create a number of newly-named headers to declare these functions, and having to add explicit include directives for them to every source file where they're needed, I have introduced a method of wrapping the corresponding public headers. parallel to the public headers in $(srcdir)/include, we now have wrappers in $(srcdir)/src/include that come earlier in the include path order. they include the public header they're wrapping, then add declarations for namespace-protected versions of the same interfaces and any "internally public" interfaces for the subsystem they correspond to. along these lines, the wrapper for features.h is now responsible for the definition of the hidden, weak, and weak_alias macros. this means source files will no longer need to include any special headers to access these features. over time, it is my expectation that the scope of what is "internally public" will expand, reducing the number of source files which need to include *_impl.h and related headers down to those which are actually implementing the corresponding subsystems, not just using them.