Clang: Extract TranslationUnitCore and (re)parse explicitly

Extract TranslationUnitCore, which is the API for the high-level
operations we need. TranslationUnit does not call any clang_* functions
anymore, except the one needed for disposing the CXTranslationUnit - for
now, we keep TranslationUnit the owner of TranslationUnitCore.

TranslationUnitCore will be passed on to the worker threads.

With this, the current "TranslationUnit" looses its meaning. We will
rename it to "Document" in a follow-up change.

                            ***

TranslationUnit::cxTranslationUnit does not implicitly
creates/parses/reparses anymore. We use more verbose update operations
now.

The test ClangIpcServer.GetCodeCompletionDependingOnArgumets fails now
because of this - CodeCompleter::completeHelper() does not recreate the
translation unit anymore, thus working on the old data.

This will be addressed in a follow-up change.

Change-Id: I6213d6f1609cd3c9a54666c84cb8b623b2fefe1c
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/tools/clangbackend/ipcsource/codecompleter.cpp

@@ -37,6 +37,7 @@
 #include "clangtranslationunit.h"
 #include "sourcerange.h"
 #include "clangunsavedfilesshallowarguments.h"
+#include "clangtranslationunitupdater.h"
 
 #include <clang-c/Index.h>
 
@@ -57,9 +58,9 @@ CodeCompletions toCodeCompletions(const ClangCodeCompleteResults &results)
 
 } // anonymous namespace
 
-CodeCompleter::CodeCompleter(TranslationUnit translationUnit,
+CodeCompleter::CodeCompleter(const TranslationUnitCore &translationUnitCore,
                              const UnsavedFiles &unsavedFiles)
-    : translationUnit(std::move(translationUnit))
+    : translationUnitCore(translationUnitCore)
     , unsavedFiles(unsavedFiles)
 {
 }
@@ -82,10 +83,10 @@ CompletionCorrection CodeCompleter::neededCorrection() const
 
 ClangCodeCompleteResults CodeCompleter::completeHelper(uint line, uint column)
 {
-    const Utf8String nativeFilePath = FilePath::toNativeSeparators(translationUnit.filePath());
+    const Utf8String nativeFilePath = FilePath::toNativeSeparators(translationUnitCore.filePath());
     UnsavedFilesShallowArguments unsaved = unsavedFiles.shallowArguments();
 
-    return clang_codeCompleteAt(translationUnit.cxTranslationUnitWithoutReparsing(),
+    return clang_codeCompleteAt(translationUnitCore.cxTranslationUnit(),
                                 nativeFilePath.constData(),
                                 line,
                                 column,
@@ -99,7 +100,7 @@ uint CodeCompleter::defaultOptions() const
     uint options = CXCodeComplete_IncludeMacros
                  | CXCodeComplete_IncludeCodePatterns;
 
-    if (translationUnit.defaultParseOptions()
+    if (TranslationUnitUpdater::defaultParseOptions()
             & CXTranslationUnit_IncludeBriefCommentsInCodeCompletion) {
         options |= CXCodeComplete_IncludeBriefComments;
     }
@@ -109,7 +110,7 @@ uint CodeCompleter::defaultOptions() const
 
 UnsavedFile &CodeCompleter::unsavedFile()
 {
-    return unsavedFiles.unsavedFile(translationUnit.filePath());
+    return unsavedFiles.unsavedFile(translationUnitCore.filePath());
 }
 
 void CodeCompleter::tryDotArrowCorrectionIfNoResults(ClangCodeCompleteResults &results,
@@ -117,10 +118,10 @@ void CodeCompleter::tryDotArrowCorrectionIfNoResults(ClangCodeCompleteResults &r
                                                      uint column)
 {
     if (results.hasNoResultsForDotCompletion()) {
-        const UnsavedFile &unsavedFile = translationUnit.unsavedFile();
+        const UnsavedFile &theUnsavedFile = unsavedFile();
         bool positionIsOk = false;
-        const uint dotPosition = unsavedFile.toUtf8Position(line, column - 1, &positionIsOk);
-        if (positionIsOk && unsavedFile.hasCharacterAt(dotPosition, '.'))
+        const uint dotPosition = theUnsavedFile.toUtf8Position(line, column - 1, &positionIsOk);
+        if (positionIsOk && theUnsavedFile.hasCharacterAt(dotPosition, '.'))
             results = completeWithArrowInsteadOfDot(line, column, dotPosition);
     }
 }
@@ -143,16 +144,5 @@ ClangCodeCompleteResults CodeCompleter::completeWithArrowInsteadOfDot(uint line,
     return results;
 }
 
-Utf8String CodeCompleter::filePath() const
-{
-    return translationUnit.filePath();
-}
-
-void CodeCompleter::checkCodeCompleteResult(CXCodeCompleteResults *completeResults)
-{
-    if (!completeResults)
-        throw CodeCompleteFailedException();
-}
-
 } // namespace ClangBackEnd