shiboken: No longer hard-code the C++ language level

The C++ language level was previously hard-coded in the default options.
This is potentially problematic for projects using shiboken and also
fell apart with Qt 5.12, where the experimental level "c++1z" used for
MSVC2017/Clang 4 no longer works due to not being able to handle
enumerator value deprecation attributes.

Introduce an enumeration to represent the level and add functions
to convert back to and forth to the respective Clang option.
Add an option to shiboken.

Add a function returning a default value for the emulated compiler,
returning C++ 14 or C++1Z for the CMSVC2017/Clang 4 case.

Task-number: PYSIDE-724
Change-Id: Ie7e19bf7f099a34e6cdaad4b462157a9a3ee8797
Reviewed-by: Christian Tismer <tismer@stackless.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp b/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp
index 09d10580c..1d8a349f1 100644
--- a/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp
+++ b/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp
@@ -32,6 +32,7 @@
 
 #include <clangparser/clangbuilder.h>
 #include <clangparser/clangutils.h>
+#include <clangparser/compilersupport.h>
 
 #include "parser/codemodel.h"
 
@@ -443,10 +444,15 @@ void AbstractMetaBuilderPrivate::sortLists()
         cls->sortFunctions();
 }
 
-FileModelItem AbstractMetaBuilderPrivate::buildDom(const QByteArrayList &arguments,
+FileModelItem AbstractMetaBuilderPrivate::buildDom(QByteArrayList arguments,
+                                                   LanguageLevel level,
                                                    unsigned clangFlags)
 {
     clang::Builder builder;
+    if (level == LanguageLevel::Default)
+        level = clang::emulatedCompilerLanguageLevel();
+    arguments.prepend(QByteArrayLiteral("-std=")
+                      + clang::languageLevelOption(level));
     FileModelItem result = clang::parse(arguments, clangFlags, builder)
         ? builder.dom() : FileModelItem();
     const clang::BaseVisitor::Diagnostics &diagnostics = builder.diagnostics();
@@ -726,9 +732,11 @@ void AbstractMetaBuilderPrivate::traverseDom(const FileModelItem &dom)
     std::puts("");
 }
 
-bool AbstractMetaBuilder::build(const QByteArrayList &arguments, unsigned clangFlags)
+bool AbstractMetaBuilder::build(const QByteArrayList &arguments,
+                                LanguageLevel level,
+                                unsigned clangFlags)
 {
-    const FileModelItem dom = d->buildDom(arguments, clangFlags);
+    const FileModelItem dom = d->buildDom(arguments, level, clangFlags);
     if (dom.isNull())
         return false;
     if (ReportHandler::isDebug(ReportHandler::MediumDebug))