[clang] [Clang][Driver][LTO] Fix empty stats filename when in LTO mode (PR #71197)

[Fangrui Song via cfe-commits]

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@@ -535,7 +535,15 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   if (D.isUsingLTO()) {
     assert(!Inputs.empty() && "Must have at least one input.");
-    addLTOOptions(ToolChain, Args, CmdArgs, Output, Inputs[0],
+    // Find the first filename InputInfo object.
+    auto Input = llvm::find_if(
+        Inputs, [](const InputInfo &II) -> bool { return II.isFilename(); });
+    if (Input == Inputs.end())
+      // For a very rare case, all of the inputs to the linker are
+      // flags. If that happens, just use the first InputInfo.
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MaskRay wrote:

In Clang, flags only refer to boolean options (i.e. not `-fxxx=yy`). It seems that the canonical term here is `InputArg`.

https://github.com/llvm/llvm-project/pull/71197