libclang: pass return code out argument by reference

r212427 formalized the message-passing pattern by making these argument
structures const. This commit changes output arguments to get passed by
reference so we can eliminate mutable fields.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212497 91177308-0d34-0410-b5e6-96231b3b80d8

tools/libclang/CIndex.cpp

@@ -2736,7 +2736,7 @@ struct ParseTranslationUnitInfo {
   ArrayRef<CXUnsavedFile> unsaved_files;
   unsigned options;
   CXTranslationUnit *out_TU;
-  mutable CXErrorCode result;
+  CXErrorCode &result;
 };
 static void clang_parseTranslationUnit_Impl(void *UserData) {
   const ParseTranslationUnitInfo *PTUI =
@@ -2751,7 +2751,6 @@ static void clang_parseTranslationUnit_Impl(void *UserData) {
   // Set up the initial return values.
   if (out_TU)
     *out_TU = nullptr;
-  PTUI->result = CXError_Failure;
 
   // Check arguments.
   if (!CIdx || !out_TU) {
@@ -2898,6 +2897,7 @@ enum CXErrorCode clang_parseTranslationUnit2(
   if (num_unsaved_files && !unsaved_files)
     return CXError_InvalidArguments;
 
+  CXErrorCode result = CXError_Failure;
   ParseTranslationUnitInfo PTUI = {
       CIdx,
       source_filename,
@@ -2906,7 +2906,7 @@ enum CXErrorCode clang_parseTranslationUnit2(
       llvm::makeArrayRef(unsaved_files, num_unsaved_files),
       options,
       out_TU,
-      CXError_Failure};
+      result};
   llvm::CrashRecoveryContext CRC;
 
   if (!RunSafely(CRC, clang_parseTranslationUnit_Impl, &PTUI)) {
@@ -2935,8 +2935,8 @@ enum CXErrorCode clang_parseTranslationUnit2(
     if (CXTranslationUnit *TU = PTUI.out_TU)
       PrintLibclangResourceUsage(*TU);
   }
-  
-  return PTUI.result;
+
+  return result;
 }
 
 unsigned clang_defaultSaveOptions(CXTranslationUnit TU) {
@@ -3039,14 +3039,12 @@ struct ReparseTranslationUnitInfo {
   CXTranslationUnit TU;
   ArrayRef<CXUnsavedFile> unsaved_files;
   unsigned options;
-  mutable int result;
+  CXErrorCode &result;
 };
 
 static void clang_reparseTranslationUnit_Impl(void *UserData) {
   const ReparseTranslationUnitInfo *RTUI =
       static_cast<ReparseTranslationUnitInfo *>(UserData);
-  RTUI->result = CXError_Failure;
-
   CXTranslationUnit TU = RTUI->TU;
   unsigned options = RTUI->options;
   (void) options;
@@ -3099,13 +3097,14 @@ int clang_reparseTranslationUnit(CXTranslationUnit TU,
   if (num_unsaved_files && !unsaved_files)
     return CXError_InvalidArguments;
 
+  CXErrorCode result = CXError_Failure;
   ReparseTranslationUnitInfo RTUI = {
       TU, llvm::makeArrayRef(unsaved_files, num_unsaved_files), options,
-      CXError_Failure};
+      result};
 
   if (getenv("LIBCLANG_NOTHREADS")) {
     clang_reparseTranslationUnit_Impl(&RTUI);
-    return RTUI.result;
+    return result;
   }
 
   llvm::CrashRecoveryContext CRC;
@@ -3117,7 +3116,7 @@ int clang_reparseTranslationUnit(CXTranslationUnit TU,
   } else if (getenv("LIBCLANG_RESOURCE_USAGE"))
     PrintLibclangResourceUsage(TU);
 
-  return RTUI.result;
+  return result;
 }
 
 

tools/libclang/Indexing.cpp

@@ -475,7 +475,7 @@ struct IndexSourceFileInfo {
   ArrayRef<CXUnsavedFile> unsaved_files;
   CXTranslationUnit *out_TU;
   unsigned TU_options;
-  mutable int result;
+  CXErrorCode &result;
 };
 
 } // anonymous namespace
@@ -494,9 +494,6 @@ static void clang_indexSourceFile_Impl(void *UserData) {
   CXTranslationUnit *out_TU  = ITUI->out_TU;
   unsigned TU_options = ITUI->TU_options;
 
-  // Set up the initial return value.
-  ITUI->result = CXError_Failure;
-
   if (out_TU)
     *out_TU = nullptr;
   bool requestedToGetTU = (out_TU != nullptr);
@@ -982,6 +979,7 @@ int clang_indexSourceFile(CXIndexAction idxAction,
   if (num_unsaved_files && !unsaved_files)
     return CXError_InvalidArguments;
 
+  CXErrorCode result = CXError_Failure;
   IndexSourceFileInfo ITUI = {
       idxAction,
       client_data,
@@ -994,11 +992,11 @@ int clang_indexSourceFile(CXIndexAction idxAction,
       llvm::makeArrayRef(unsaved_files, num_unsaved_files),
       out_TU,
       TU_options,
-      CXError_Failure};
+      result};
 
   if (getenv("LIBCLANG_NOTHREADS")) {
     clang_indexSourceFile_Impl(&ITUI);
-    return ITUI.result;
+    return result;
   }
 
   llvm::CrashRecoveryContext CRC;
@@ -1029,8 +1027,8 @@ int clang_indexSourceFile(CXIndexAction idxAction,
     if (out_TU)
       PrintLibclangResourceUsage(*out_TU);
   }
-  
-  return ITUI.result;
+
+  return result;
 }
 
 int clang_indexTranslationUnit(CXIndexAction idxAction,