7 files changed, 25 insertions, 1 deletions
diff --git a/clang/include/clang-c/Index.h b/clang/include/clang-c/Index.h
index 86383d13510..56b510d03ab 100644
--- a/clang/include/clang-c/Index.h
+++ b/clang/include/clang-c/Index.h
@@ -5606,9 +5606,14 @@ enum CXCompletionContext {
   CXCompletionContext_NaturalLanguage = 1 << 21,
 
   /**
+   * #include file completions should be included in the results.
+   */
+  CXCompletionContext_IncludedFile = 1 << 22,
+
+  /**
    * The current context is unknown, so set all contexts.
    */
-  CXCompletionContext_Unknown = ((1 << 22) - 1)
+  CXCompletionContext_Unknown = ((1 << 23) - 1)
 };
 
 /**
diff --git a/clang/include/clang/Lex/CodeCompletionHandler.h b/clang/include/clang/Lex/CodeCompletionHandler.h
index 87089fd7d50..6b368c74c5f 100644
--- a/clang/include/clang/Lex/CodeCompletionHandler.h
+++ b/clang/include/clang/Lex/CodeCompletionHandler.h
@@ -14,6 +14,8 @@
 #ifndef LLVM_CLANG_LEX_CODECOMPLETIONHANDLER_H
 #define LLVM_CLANG_LEX_CODECOMPLETIONHANDLER_H
 
+#include "llvm/ADT/StringRef.h"
+
 namespace clang {
 
 class IdentifierInfo;
@@ -60,6 +62,11 @@ public:
                                          MacroInfo *MacroInfo,
                                          unsigned ArgumentIndex) { }
 
+  /// Callback invoked when performing code completion inside the filename
+  /// part of an #include directive. (Also #import, #include_next, etc).
+  /// \p Dir is the directory relative to the include path, e.g. "a" for <a/b.
+  virtual void CodeCompleteIncludedFile(llvm::StringRef Dir, bool IsAngled) {}
+
   /// Callback invoked when performing code completion in a part of the
   /// file where we expect natural language, e.g., a comment, string, or
   /// \#error directive.
diff --git a/clang/include/clang/Lex/Lexer.h b/clang/include/clang/Lex/Lexer.h
index 7af9d43b3f5..a9b10b62732 100644
--- a/clang/include/clang/Lex/Lexer.h
+++ b/clang/include/clang/Lex/Lexer.h
@@ -711,6 +711,9 @@ private:
 
   bool isHexaLiteral(const char *Start, const LangOptions &LangOpts);
 
+  void codeCompleteIncludedFile(const char *PathStart,
+                                const char *CompletionPoint, bool IsAngled);
+
   /// Read a universal character name.
   ///
   /// \param StartPtr The position in the source buffer after the initial '\'.
diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
index 02ea80aa3fc..75910011d04 100644
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -1128,6 +1128,10 @@ public:
     CodeComplete = nullptr;
   }
 
+  /// Hook used by the lexer to invoke the "included file" code
+  /// completion point.
+  void CodeCompleteIncludedFile(llvm::StringRef Dir, bool IsAngled);
+
   /// Hook used by the lexer to invoke the "natural language" code
   /// completion point.
   void CodeCompleteNaturalLanguage();
diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
index 5b3bfb5a077..e70a19be47d 100644
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -2969,6 +2969,7 @@ private:
   void CodeCompletePreprocessorExpression() override;
   void CodeCompleteMacroArgument(IdentifierInfo *Macro, MacroInfo *MacroInfo,
                                  unsigned ArgumentIndex) override;
+  void CodeCompleteIncludedFile(llvm::StringRef Dir, bool IsAngled) override;
   void CodeCompleteNaturalLanguage() override;
 };
 
diff --git a/clang/include/clang/Sema/CodeCompleteConsumer.h b/clang/include/clang/Sema/CodeCompleteConsumer.h
index 9e1c7e257c7..3e7286b8e9f 100644
--- a/clang/include/clang/Sema/CodeCompleteConsumer.h
+++ b/clang/include/clang/Sema/CodeCompleteConsumer.h
@@ -323,6 +323,9 @@ public:
     /// Code completion where an Objective-C category name is expected.
     CCC_ObjCCategoryName,
 
+    /// Code completion inside the filename part of a #include directive.
+    CCC_IncludedFile,
+
     /// An unknown context, in which we are recovering from a parsing
     /// error and don't know which completions we should give.
     CCC_Recovery
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 293b5481015..a701876948f 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -10345,6 +10345,7 @@ public:
                                              IdentifierInfo *Macro,
                                              MacroInfo *MacroInfo,
                                              unsigned Argument);
+  void CodeCompleteIncludedFile(llvm::StringRef Dir, bool IsAngled);
   void CodeCompleteNaturalLanguage();
   void CodeCompleteAvailabilityPlatformName();
   void GatherGlobalCodeCompletions(CodeCompletionAllocator &Allocator,