Clang: Fix infinite loop when resolving pointer type

Fixes: QTCREATORBUG-22010
Change-Id: I5a2932089e9f7fb1e283635e228192fdb7e59cab
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/tools/clangbackend/source/clangtooltipinfocollector.cpp

@@ -36,6 +36,7 @@
 #include <clangsupport/sourcerangecontainer.h>
 #include <utils/qtcassert.h>
 #include <utils/textfileformat.h>
+#include <utils/qtcassert.h>
 
 #include <utf8string.h>
 
@@ -392,7 +393,7 @@ static bool isBuiltinOrPointerToBuiltin(const Type &type)
 
     // TODO: Simplify
     // TODO: Test with **
-    while (theType.pointeeType().isValid()) {
+    while (theType.pointeeType().isValid() && theType != theType.pointeeType()) {
         theType = theType.pointeeType();
         if (theType.isBuiltinType())
             return true;
@@ -436,7 +437,7 @@ ToolTipInfo ToolTipInfoCollector::qDocInfo(const Cursor &cursor) const
         }
 
         Type type = cursor.type();
-        while (type.pointeeType().isValid())
+        while (type.pointeeType().isValid() && type != type.pointeeType())
             type = type.pointeeType();
 
         const Cursor typeCursor = type.declaration();

src/tools/clangbackend/source/clangtype.cpp

@@ -245,6 +245,11 @@ bool operator==(Type first, Type second)
     return clang_equalTypes(first.m_cxType, second.m_cxType);
 }
 
+bool operator!=(Type first, Type second)
+{
+    return !operator==(first, second);
+}
+
 std::ostream &operator<<(std::ostream &os, CXTypeKind typeKind)
 {
     ClangString typeKindSpelling(clang_getTypeKindSpelling(typeKind));

src/tools/clangbackend/source/clangtype.h

@@ -81,6 +81,7 @@ private:
 };
 
 bool operator==(Type first, Type second);
+bool operator!=(Type first, Type second);
 
 std::ostream &operator<<(std::ostream &os, CXTypeKind typeKind);
 std::ostream &operator<<(std::ostream &os, const Type &type);