[libclang] Introduce options to control the priority for the threads

that libclang creates.

-Introduce CXGlobalOptFlags enum for the new options that can be
 set on the CXIndex object.

-CXGlobalOpt_ThreadBackgroundPriorityForIndexing affects:
  clang_indexSourceFile
  clang_indexTranslationUnit
  clang_parseTranslationUnit
  clang_saveTranslationUnit

-CXGlobalOpt_ThreadBackgroundPriorityForEditing affects:
  clang_reparseTranslationUnit
  clang_codeCompleteAt
  clang_annotateTokens

rdar://9075282

llvm-svn: 153562

1 files changed, 55 insertions, 0 deletions

diff --git a/clang/include/clang-c/Index.h b/clang/include/clang-c/Index.h
index 8d7d8595bd2..54f461b9a10 100644
--- a/clang/include/clang-c/Index.h
+++ b/clang/include/clang-c/Index.h
@@ -204,6 +204,61 @@ CINDEX_LINKAGE CXIndex clang_createIndex(int excludeDeclarationsFromPCH,
  */
 CINDEX_LINKAGE void clang_disposeIndex(CXIndex index);
 
+typedef enum {
+  /**
+   * \brief Used to indicate that no special CXIndex options are needed.
+   */
+  CXGlobalOpt_None = 0x0,
+
+  /**
+   * \brief Used to indicate that threads that libclang creates for indexing
+   * purposes should use background priority.
+   * Affects \see clang_indexSourceFile, \see clang_indexTranslationUnit,
+   * \see clang_parseTranslationUnit, \see clang_saveTranslationUnit.
+   */
+  CXGlobalOpt_ThreadBackgroundPriorityForIndexing = 0x1,
+
+  /**
+   * \brief Used to indicate that threads that libclang creates for editing
+   * purposes should use background priority.
+   * Affects \see clang_reparseTranslationUnit, \see clang_codeCompleteAt,
+   * \see clang_annotateTokens
+   */
+  CXGlobalOpt_ThreadBackgroundPriorityForEditing = 0x2,
+
+  /**
+   * \brief Used to indicate that all threads that libclang creates should use
+   * background priority.
+   */
+  CXGlobalOpt_ThreadBackgroundPriorityForAll =
+      CXGlobalOpt_ThreadBackgroundPriorityForIndexing |
+      CXGlobalOpt_ThreadBackgroundPriorityForEditing
+
+} CXGlobalOptFlags;
+
+/**
+ * \brief Sets general options associated with a CXIndex. 
+ *
+ * For example:
+ * \code
+ * CXIndex idx = ...;
+ * clang_CXIndex_setGlobalOptions(idx,
+ *     clang_CXIndex_getGlobalOptions(idx) |
+ *     CXGlobalOpt_ThreadBackgroundPriorityForIndexing);
+ * \endcode
+ *
+ * \param options A bitmask of options, a bitwise OR of CXGlobalOpt_XXX flags.
+ */
+CINDEX_LINKAGE void clang_CXIndex_setGlobalOptions(CXIndex, unsigned options);
+
+/**
+ * \brief Gets the general options associated with a CXIndex.
+ *
+ * \returns A bitmask of options, a bitwise OR of CXGlobalOpt_XXX flags that
+ * are associated with the given CXIndex object.
+ */
+CINDEX_LINKAGE unsigned clang_CXIndex_getGlobalOptions(CXIndex);
+
 /**
  * \defgroup CINDEX_FILES File manipulation routines
  *