[clangd] Avoid "expected one compiler job" by picking the first eligible job.

This happens in createInvocationWithCommandLine but only clangd currently passes
ShouldRecoverOnErorrs (sic).

One cause of this (with correct command) is several -arch arguments for mac
multi-arch support.

Fixes https://github.com/clangd/clangd/issues/827

Differential Revision: https://reviews.llvm.org/D107632

1 files changed, 8 insertions, 6 deletions

diff --git a/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp b/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
index 2e23ebf..2a14b7a 100644
--- a/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
+++ b/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
@@ -79,22 +79,24 @@ std::unique_ptr<CompilerInvocation> clang::createInvocationFromCommandLine(
       }
     }
   }
-  if (Jobs.size() == 0 || !isa<driver::Command>(*Jobs.begin()) ||
-      (Jobs.size() > 1 && !OffloadCompilation)) {
+
+  bool PickFirstOfMany = OffloadCompilation || ShouldRecoverOnErorrs;
+  if (Jobs.size() == 0 || (Jobs.size() > 1 && !PickFirstOfMany)) {
     SmallString<256> Msg;
     llvm::raw_svector_ostream OS(Msg);
     Jobs.Print(OS, "; ", true);
     Diags->Report(diag::err_fe_expected_compiler_job) << OS.str();
     return nullptr;
   }
-
-  const driver::Command &Cmd = cast<driver::Command>(*Jobs.begin());
-  if (StringRef(Cmd.getCreator().getName()) != "clang") {
+  auto Cmd = llvm::find_if(Jobs, [](const driver::Command &Cmd) {
+    return StringRef(Cmd.getCreator().getName()) == "clang";
+  });
+  if (Cmd == Jobs.end()) {
     Diags->Report(diag::err_fe_expected_clang_command);
     return nullptr;
   }
 
-  const ArgStringList &CCArgs = Cmd.getArguments();
+  const ArgStringList &CCArgs = Cmd->getArguments();
   if (CC1Args)
     *CC1Args = {CCArgs.begin(), CCArgs.end()};
   auto CI = std::make_unique<CompilerInvocation>();