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

[Fraser Cormack 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");
+    if (LibPath) {
+      SmallVector<StringRef, 8> Frags;
+      const char EnvPathSeparatorStr[] = {llvm::sys::EnvPathSeparator, '\0'};
+      llvm::SplitString(*LibPath, Frags, EnvPathSeparatorStr);
+      for (StringRef Path : Frags)
+        LibraryPaths.emplace_back(Path.trim());
+    }
+
+    // Find device libraries in <LLVM_DIR>/lib/clang/<ver>/lib/libclc/
+    SmallString<128> LibclcPath(D.ResourceDir);
+    llvm::sys::path::append(LibclcPath, "lib", "libclc");
+    LibraryPaths.emplace_back(LibclcPath);
+
+    bool FoundBCLibrary = false;
+    StringRef LibclcNamespec(A->getValue());
+
+    // If the namespec is of the form :filename, search for that file.
+    bool FilenameSearch = LibclcNamespec.starts_with(":");
+    SmallString<128> LibclcTargetFile(
+        LibclcNamespec.drop_front(FilenameSearch ? 1 : 0));
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frasercrmck wrote:

Oh yeah good idea, thanks.

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