3 files changed, 20 insertions, 1 deletions
diff --git a/include/clang-c/Index.h b/include/clang-c/Index.h
index 65dada38b0..0dce9f2f27 100644
--- a/include/clang-c/Index.h
+++ b/include/clang-c/Index.h
@@ -33,6 +33,7 @@
  */
 #define CINDEX_VERSION_MAJOR 0
 #define CINDEX_VERSION_MINOR 49
+#define CINDEX_VERSION_HAS_SKIPWARNINGSFROMINCLUDEDFILES_BACKPORTED
 
 #define CINDEX_VERSION_ENCODE(major, minor) ( \
       ((major) * 10000)                       \
@@ -1332,7 +1333,17 @@ enum CXTranslationUnit_Flags {
    *
    * The function bodies of the main file are not skipped.
    */
-  CXTranslationUnit_LimitSkipFunctionBodiesToPreamble = 0x800
+  CXTranslationUnit_LimitSkipFunctionBodiesToPreamble = 0x800,
+
+  /**
+   * Used to indicate that non-errors from included files should be ignored.
+   *
+   * If set, clang_getDiagnosticSetFromTU() will not report e.g. warnings from
+   * included files anymore. This speeds up clang_getDiagnosticSetFromTU() for
+   * the case where these warnings are not of interest, as for an IDE for
+   * example, which typically shows only the diagnostics in the main file.
+   */
+  CXTranslationUnit_IgnoreNonErrorsFromIncludedFiles = 0x1000
 };
 
 /**
diff --git a/include/clang/Basic/Diagnostic.h b/include/clang/Basic/Diagnostic.h
index d30ac14e02..89ccb3e0e2 100644
--- a/include/clang/Basic/Diagnostic.h
+++ b/include/clang/Basic/Diagnostic.h
@@ -213,6 +213,9 @@ private:
   // Suppress all diagnostics.
   bool SuppressAllDiagnostics = false;
 
+  // Suppress non-errors from all included files.
+  bool SuppressNonErrorsFromIncludedFiles = false;
+
   // Elide common types of templates.
   bool ElideType = true;
 
@@ -634,6 +637,10 @@ public:
   }
   bool getSuppressAllDiagnostics() const { return SuppressAllDiagnostics; }
 
+  void setSuppressNonErrorsFromIncludedFiles(bool Val = true) {
+    SuppressNonErrorsFromIncludedFiles = Val;
+  }
+
   /// Set type eliding, to skip outputting same types occurring in
   /// template types.
   void setElideType(bool Val = true) { ElideType = Val; }
diff --git a/include/clang/Frontend/ASTUnit.h b/include/clang/Frontend/ASTUnit.h
index a58cf53943..88c8370c24 100644
--- a/include/clang/Frontend/ASTUnit.h
+++ b/include/clang/Frontend/ASTUnit.h
@@ -43,6 +43,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <memory>
+#include <mutex>
 #include <string>
 #include <utility>
 #include <vector>