[clang] AMDGPU: Find device files even when ROCM_PATH is set (PR #177346)

[Matt Arsenault via cfe-commits]

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@@ -207,16 +211,15 @@ RocmInstallationDetector::getInstallationPathCandidates() {
 
   // For candidate specified by --rocm-path we do not do strict check, i.e.,
   // checking existence of HIP version file and device library files.
+  // These are added first as highest priority candidates, but we continue
+  // to add clang-relative paths to support cases where the compiler has its
+  // own device libraries (e.g., python wheels with bundled device libs).
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arsenm wrote:

I think the resource directory should take precedent over all else. There's an existing flag to manually specify the resource directory if you really want. 

Also, using environment variables to communicate this to the compiler is also quite bad. Does any other clang driver use those for paths? All the uses should probably migrate onto using the device lib path 


https://github.com/llvm/llvm-project/pull/177346