CppEditor: Fix codemodel highlighting for QNX

The code model will get the necessary bits so that it can successfully
parse the QNX code.

Fixes: QTCREATORBUG-23483
Change-Id: Id9488f644ace23952edf7a7cb5da7ca138182134
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/cppeditor/compileroptionsbuilder.cpp

@@ -35,6 +35,8 @@
 #include <projectexplorer/projectexplorerconstants.h>
 #include <projectexplorer/projectmacro.h>
 
+#include <qnx/qnxconstants.h>
+
 #include <utils/algorithm.h>
 #include <utils/cpplanguage_details.h>
 #include <utils/fileutils.h>
@@ -152,6 +154,7 @@ QStringList CompilerOptionsBuilder::build(ProjectFile::Kind fileKind,
     undefineClangVersionMacrosForMsvc();
     undefineCppLanguageFeatureMacrosForMsvc2015();
     addDefineFunctionMacrosMsvc();
+    addDefineFunctionMacrosQnx();
 
     addHeaderPathOptions();
 
@@ -404,8 +407,8 @@ void CompilerOptionsBuilder::addProjectMacros()
     static const int useMacros = qEnvironmentVariableIntValue("QTC_CLANG_USE_TOOLCHAIN_MACROS");
 
     if (m_projectPart.toolchainType == ProjectExplorer::Constants::CUSTOM_TOOLCHAIN_TYPEID
-            || m_projectPart.toolchainType.name().contains("BareMetal")
+        || m_projectPart.toolchainType == Qnx::Constants::QNX_TOOLCHAIN_ID
-            || useMacros) {
+        || m_projectPart.toolchainType.name().contains("BareMetal") || useMacros) {
         addMacros(m_projectPart.toolChainMacros);
     }
 
@@ -771,6 +774,17 @@ void CompilerOptionsBuilder::undefineClangVersionMacrosForMsvc()
     }
 }
 
+void CompilerOptionsBuilder::addDefineFunctionMacrosQnx()
+{
+    // QNX 7.0+ uses GCC with LIBCPP from Clang, and in that context GCC is giving
+    // the builtin operator new and delete.
+    //
+    // In our case we have only Clang and need to instruct LIBCPP that it doesn't
+    // have these operators. This makes the code model happy and doesn't produce errors.
+    if (m_projectPart.toolchainType == Qnx::Constants::QNX_TOOLCHAIN_ID)
+        addMacros({{"_LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE"}});
+}
+
 void CompilerOptionsBuilder::reset()
 {
     m_options.clear();

src/plugins/cppeditor/compileroptionsbuilder.h

@@ -84,6 +84,8 @@ public:
     void addProjectConfigFileInclude();
     void undefineClangVersionMacrosForMsvc();
 
+    void addDefineFunctionMacrosQnx();
+
     // Add custom options
     void add(const QString &arg, bool gccOnlyOption = false);
     void prepend(const QString &arg);

src/plugins/qnx/qnxtoolchain.cpp

@@ -185,7 +185,13 @@ void QnxToolChain::setCpuDir(const QString &cpuDir)
 
 GccToolChain::DetectedAbisResult QnxToolChain::detectSupportedAbis() const
 {
-    return detectTargetAbis(m_sdpPath);
+    // "unknown-qnx-gnu"is needed to get the "--target=xxx" parameter sent code model,
+    // which gets translated as "x86_64-qnx-gnu", which gets Clang to happily parse
+    // the QNX code.
+    //
+    // Without it on Windows Clang defaults to a MSVC mode, which breaks with
+    // the QNX code, which is mostly GNU based.
+    return GccToolChain::DetectedAbisResult{detectTargetAbis(m_sdpPath), "unknown-qnx-gnu"};
 }
 
 bool QnxToolChain::operator ==(const ToolChain &other) const