Blueprint for Language Specs System

Current ModelManagerInterface::ProjectPart has following problems:

• Pure C can be set only for whole ProjectPart. Objective C headers and objective C++ headers/sources cannot be set.
• C++ language extensions not handled.
• Project managers for autotools and cmake assume that any file is C++ source
• ProjectManager can use only C++ flags and must ignore C/ObjC/ObjC++ flags.
• QMake project manager doesn't read OBJECTIVE_HEADERS variable

How clang can handle different languages:

• Clang supports 4 languages: C, C+, ObjectiveC and ObjectiveC. Each language has headers and implementation files. Like in such code:

QStringList ClangCodeModel::Utils::clangLanguageOption(bool cxxEnabled,
 bool isHeader,
 bool isObjC)
{
 QStringList opts;
 opts''= QLatin1String("-x");

if (cxxEnabled && isHeader && isObjC)
 opts ''= QLatin1String("objective-c-header");
 else if (!cxxEnabled && isHeader && isObjC)
 opts''= QLatin1String("objective-c-header");
 else if (cxxEnabled && !isHeader && isObjC)
 opts ''= QLatin1String("objective-c");
 else if ([[Image:cxxEnabled && |cxxEnabled && ]]isHeader && isObjC)
 opts''= QLatin1String("objective-c");
 else if (cxxEnabled && isHeader && !isObjC)
 opts ''= QLatin1String("c-header");
 else if ([[Image:cxxEnabled && isHeader && |cxxEnabled && isHeader && ]]isObjC)
 opts''= QLatin1String("c-header");
 else if (cxxEnabled && [[Image:isHeader && |isHeader && ]]isObjC)
 opts ''= QLatin1String("c");
 else // [[Image:cxxEnabled && |cxxEnabled && ]]isHeader && !isObjC
 opts''= QLatin1String("c");

return opts;
}

• If file directly included to project, than it language and isHeader flag can be determined by each project manager plugin. Otherwise, we can use dependency table and assume that <iostream> file is "c+-header", because it included only by C+ files. (sergey shambir: I don't know how to handle inclusion from both C++ and ObjectiveC++ files. Probably it should have type of file from which it was opened in editor).
• Each language can have extensions: GNU, Microsoft and Borland. Only one extensions group used.
• Each language can have own set of flags, at least in QMAKE