"Multiple parse contexts" in Qt creator

[koahnig]

Not sure what is meant here:

This comes from Qt creator latest version 4.3.1 on windows 10,in case it matters.

I am at a loss what I can do to get rid of it. Obviously, I can use "Do Not Show Again" which is on the right of the message, but I prefer to know, what I am ignoring.

What are possible causes?

[aha_1980]

Most likely you have multiple (Sub-)projects containg this file. Depending on the parse context, different defines may be active that influence the parsing of this file

[mrjj]

Hi
Do you use sessions?
https://bugreports.qt.io/browse/QTCREATORBUG-18521

Anyway, its not clear from source what is being checked

CppTools::BaseEditorDocumentProcessor *CppEditorDocument::processor()
{
  ...
            const bool isAmbiguous = info.hints & ProjectPartInfo::IsAmbiguousMatch;
            const bool isProjectFile = info.hints & ProjectPartInfo::IsFromProjectMatch;
            showHideInfoBarAboutMultipleParseContexts(isAmbiguous && isProjectFile); // this shows msg

The IsFromProjectMatch flag is set here
cppprojectpartchooser.cpp

        // Hints
        if (m_info.projectParts.size() > 1)
            m_info.hints |= ProjectPartInfo::IsAmbiguousMatch;
        if (prioritized.first().priority > 1000)
            m_info.hints |= ProjectPartInfo::IsPreferredMatch;
        if (areProjectPartsFromDependencies)
            m_info.hints |= ProjectPartInfo::IsFromDependenciesMatch;
        else
            m_info.hints |= ProjectPartInfo::IsFromProjectMatch;

so it seems to be related to sort / classify files depending on origin but didnt really see the meaning of
multiple contexts.

update: yep, as @aha_1980 says, sub projects might trigger this , it seems from the code.

[Added code tags ~kshegunov]

[koahnig]

Thanks guys.

Yes, I am using subprojects.
Yes, I am using sessions.

Within the session I have/had a couple of projects which I have also put into a subdirs project,which is also open.

Apparently the message is an one time display, because it does not vanish after:

• closing the duplicates
• changing to another file

I was using a search over all projects with some text. That might have triggered the message.
I guess for the first time, it might make sense for a file. However, when switching to another file, the meaning is lost, because the message refers to "this file".

The description of the bug report does not really fit my case.

How can I choose a prefered one then?

[aha_1980]

you can select the active parse context with drop down box (3) from http://doc.qt.io/qtcreator/creator-coding-navigating.html

[koahnig]

@aha_1980

Thanks for link. That is exactly what I was looking for.

As a side note, the dropdown box is not always visible. I had realized that there was something, but could not really make it out. In addition the content was not obviously related to my issue. Probably, I have seen the box the first time in that context.
IMHO the warning text is ambigious, which causes confusion. However, rather than just complaining about it, which is always easy, I cannot offer an alternative text.

[paulf]

@aha_1980

No subprojects. No sessions. Choosing C++ from the Parse Contect drop down does nothing.

From what I can tell the reason that this is badly broken is that the GUI only lets you choose between C and C++ to resolve "parse contexts". Looking at the source "ProjectPart" has the following fields, and it is totally opaque from the GUI as to why a file has more than one of these ProjectParts

public:
ProjectExplorer::Project *project = nullptr;

QString displayName;

QString projectFile;
int projectFileLine = -1;
int projectFileColumn = -1;
QString callGroupId;

// Versions, features and extensions
::Utils::Language language = ::Utils::Language::Cxx;
::Utils::LanguageVersion languageVersion = ::Utils::LanguageVersion::LatestCxx;
::Utils::LanguageExtensions languageExtensions = ::Utils::LanguageExtension::None;
CPlusPlus::LanguageFeatures languageFeatures;
::Utils::QtVersion qtVersion = ::Utils::QtVersion::Unknown;

// Files
ProjectFiles files;
QStringList includedFiles;
QStringList precompiledHeaders;
ProjectExplorer::HeaderPaths headerPaths;
QString projectConfigFile; // Generic Project Manager only

// Macros
ProjectExplorer::Macros projectMacros;
ProjectExplorer::Macros toolChainMacros;

// Build system
QString buildSystemTarget;
ProjectExplorer::BuildTargetType buildTargetType = ProjectExplorer::BuildTargetType::Unknown;
bool selectedForBuilding = true;

// ToolChain
Utils::Id toolchainType;
bool isMsvc2015Toolchain = false;
QString toolChainTargetTriple;
ToolChainWordWidth toolChainWordWidth = WordWidth32Bit;
::Utils::FilePath toolChainInstallDir;
::Utils::WarningFlags warningFlags = ::Utils::WarningFlags::Default;

// Misc
QStringList extraCodeModelFlags;
QStringList compilerFlags;