[clang-doc] Fix warnings about lock_guard

Fixes a warning about a potentially unsupported template argument
deduction by explicitly specifying the template type in std::lock_guard.

Patch By: brettw
Differential Revision: https://reviews.llvm.org/D138961

1 files changed, 2 insertions, 2 deletions

diff --git a/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp b/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
index 83bfea027bbc..2ece3e4c071d 100644
--- a/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
+++ b/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
@@ -264,13 +264,13 @@ Example usage for a project using a compile commands database:
 
       // Add a reference to this Info in the Index
       {
-        std::lock_guard Guard(IndexMutex);
+        std::lock_guard<llvm::sys::Mutex> Guard(IndexMutex);
         clang::doc::Generator::addInfoToIndex(CDCtx.Idx, Reduced.get().get());
       }
 
       // Save in the result map (needs a lock due to threaded access).
       {
-        std::lock_guard Guard(USRToInfoMutex);
+        std::lock_guard<llvm::sys::Mutex> Guard(USRToInfoMutex);
         USRToInfo[Group.getKey()] = std::move(Reduced.get());
       }
     });