
This is a fairly large changeset, but it can be broken into a few pieces: - `llvm/Support/*TargetParser*` are all moved from the LLVM Support component into a new LLVM Component called "TargetParser". This potentially enables using tablegen to maintain this information, as is shown in https://reviews.llvm.org/D137517. This cannot currently be done, as llvm-tblgen relies on LLVM's Support component. - This also moves two files from Support which use and depend on information in the TargetParser: - `llvm/Support/Host.{h,cpp}` which contains functions for inspecting the current Host machine for info about it, primarily to support getting the host triple, but also for `-mcpu=native` support in e.g. Clang. This is fairly tightly intertwined with the information in `X86TargetParser.h`, so keeping them in the same component makes sense. - `llvm/ADT/Triple.h` and `llvm/Support/Triple.cpp`, which contains the target triple parser and representation. This is very intertwined with the Arm target parser, because the arm architecture version appears in canonical triples on arm platforms. - I moved the relevant unittests to their own directory. And so, we end up with a single component that has all the information about the following, which to me seems like a unified component: - Triples that LLVM Knows about - Architecture names and CPUs that LLVM knows about - CPU detection logic for LLVM Given this, I have also moved `RISCVISAInfo.h` into this component, as it seems to me to be part of that same set of functionality. If you get link errors in your components after this patch, you likely need to add TargetParser into LLVM_LINK_COMPONENTS in CMake. Differential Revision: https://reviews.llvm.org/D137838
llvm/lib/Support/Unix README =========================== This directory provides implementations of the lib/System classes that are common to two or more variants of UNIX. For example, the directory structure underneath this directory could look like this: Unix - only code that is truly generic to all UNIX platforms Posix - code that is specific to Posix variants of UNIX SUS - code that is specific to the Single Unix Specification SysV - code that is specific to System V variants of UNIX As a rule, only those directories actually needing to be created should be created. Also, further subdirectories could be created to reflect versions of the various standards. For example, under SUS there could be v1, v2, and v3 subdirectories to reflect the three major versions of SUS.