[clang] [libclc] [clang] Add the ability to link libclc OpenCL libraries (PR #146503)

[Matt Arsenault via cfe-commits]

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@@ -2942,6 +2942,65 @@ void tools::addHIPRuntimeLibArgs(const ToolChain &TC, Compilation &C,
   }
 }
 
+void tools::addOpenCLBuiltinsLib(const Driver &D,
+                                 const llvm::opt::ArgList &DriverArgs,
+                                 llvm::opt::ArgStringList &CC1Args) {
+  // Check whether user specifies a libclc bytecode library
+  if (const Arg *A = DriverArgs.getLastArg(options::OPT_libclc_lib_EQ)) {
+    SmallVector<StringRef, 8> LibraryPaths;
+
+    // Add user defined library paths from LIBRARY_PATH.
+    std::optional<std::string> LibPath =
+        llvm::sys::Process::GetEnv("LIBRARY_PATH");
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arsenm wrote:

I'd consider any compiler usage of environment variables to be a legacy issue, and only explicit command line flags should be introduced. But yes resource directory preferred 

https://github.com/llvm/llvm-project/pull/146503