[clang] allow -fthinlto-index= without -x ir

Summary:
Previously, passing -fthinlto-index= to clang required that bitcode
files be explicitly marked by -x ir. This change makes us detect files
with object file extensions as bitcode files when -fthinlto-index= is
present, so that explicitly marking them is no longer necessary.
Explicitly specifying -x ir is still accepted and continues to be part
of the test case to ensure we continue to support it.

Reviewers: tejohnson, rnk, pcc

Subscribers: mehdi_amini, steven_wu, dexonsmith, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64610

llvm-svn: 366127

1 files changed, 6 insertions, 0 deletions

diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 22f26d90bd7..087335562d0 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -2119,6 +2119,12 @@ void Driver::BuildInputs(const ToolChain &TC, DerivedArgList &Args,
               Diag(clang::diag::warn_drv_treating_input_as_cxx)
                   << getTypeName(OldTy) << getTypeName(Ty);
           }
+
+          // If running with -fthinlto-index=, extensions that normally identify
+          // native object files actually identify LLVM bitcode files.
+          if (Args.hasArgNoClaim(options::OPT_fthinlto_index_EQ) &&
+              Ty == types::TY_Object)
+            Ty = types::TY_LLVM_BC;
         }
 
         // -ObjC and -ObjC++ override the default language, but only for "source