[clang-tidy] Implement type-based check for `gsl::owner`

This check implements the typebased semantic of `gsl::owner`.
Meaning, that 
- only `gsl::owner` is allowed to get `delete`d
- `new` expression must be assigned to `gsl::owner`
- function calls that expect `gsl::owner` as argument, must get either an owner
  or a newly created and recognized resource (in the moment only `new`ed memory)
- assignment to `gsl::owner` must be either a resource or another owner
- functions returning an `gsl::owner` are considered as factories, and their result
  must be assigned to an `gsl::owner`
- classes that have an `gsl::owner`-member must declare a non-default destructor

There are some problems that occur when typededuction is in place.
For example `auto Var = function_that_returns_owner();` the type of `Var` will not be
an `gsl::owner`. This case is catched, and explicitly noted.

But cases like fully templated functions
```
template <typename T> 
void f(T t) { delete t; }
// ...
f(gsl::owner<int*>(new int(42)));
```
Will created false positive (the deletion is problematic), since the type deduction
removes the wrapping `typeAlias`.

Please give your comments :)

llvm-svn: 313043

1 files changed, 3 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp
index 6b9de8d3905..454adc9fd19 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp
@@ -13,6 +13,7 @@
 #include "../misc/UnconventionalAssignOperatorCheck.h"
 #include "InterfacesGlobalInitCheck.h"
 #include "NoMallocCheck.h"
+#include "OwningMemoryCheck.h"
 #include "ProBoundsArrayToPointerDecayCheck.h"
 #include "ProBoundsConstantArrayIndexCheck.h"
 #include "ProBoundsPointerArithmeticCheck.h"
@@ -37,6 +38,8 @@ public:
     CheckFactories.registerCheck<InterfacesGlobalInitCheck>(
         "cppcoreguidelines-interfaces-global-init");
     CheckFactories.registerCheck<NoMallocCheck>("cppcoreguidelines-no-malloc");
+    CheckFactories.registerCheck<OwningMemoryCheck>(
+        "cppcoreguidelines-owning-memory");
     CheckFactories.registerCheck<ProBoundsArrayToPointerDecayCheck>(
         "cppcoreguidelines-pro-bounds-array-to-pointer-decay");
     CheckFactories.registerCheck<ProBoundsConstantArrayIndexCheck>(