[clang-tidy] new cppcoreguidelines-slicing

Flags slicing of member variables or vtable. See:

https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#es63-dont-slice
https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#c145-access-polymorphic-objects-through-pointers-and-references

Differential revision:
http://reviews.llvm.org/D21974

llvm-svn: 276408

clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp

@@ -22,6 +22,7 @@
 #include "ProTypeStaticCastDowncastCheck.h"
 #include "ProTypeUnionAccessCheck.h"
 #include "ProTypeVarargCheck.h"
+#include "SlicingCheck.h"
 
 namespace clang {
 namespace tidy {
@@ -53,6 +54,8 @@ public:
         "cppcoreguidelines-pro-type-union-access");
     CheckFactories.registerCheck<ProTypeVarargCheck>(
         "cppcoreguidelines-pro-type-vararg");
+    CheckFactories.registerCheck<SlicingCheck>(
+        "cppcoreguidelines-slicing");
     CheckFactories.registerCheck<misc::UnconventionalAssignOperatorCheck>(
         "cppcoreguidelines-c-copy-assignment-signature");
   }