[libclc] More cross compilation fixes (#97811)
* Move the setup_host_tool calls to the directories of their tool.
Although it works to call it in libclc, it can only appear in a single
location so it fails the "what if everyone did this?" test and causes
problems for downstream code that also wants to use native versions of
these tools from other projects.
* Correct the TARGET "${${tool}_target}" check. "${${tool}_target}" may
be set to the path to the executable, which works in dependencies but
cannot be tested using if(TARGET). For lack of a better alternative,
just check that "${${tool}_target}" is non-empty and trust that if it
is, it is set to a meaningful value. If somehow it turns out to be a
valid target, its value will still show up in error messages anyway.
* Account for llvm-spirv possibly being provided in-tree. Per
https://github.com/KhronosGroup/SPIRV-LLVM-Translator?tab=readme-ov-file#llvm-in-tree-build
it is possible to drop llvm-spirv into LLVM and have it built as part of
LLVM's build. In this configuration, cross builds of LLVM require a
native version of llvm-spirv to be built.
GitOrigin-RevId: 903d1c6ee5de4ee87c1737906c264e219c05d4cb
1 file changed
