[clang][PAC] Don't try to diagnose use of pointer auth on dependent types #159505

[ojhunt]

We can't give a correct answer for dependent types, so for now just report no ptrauth involves if the type being queried is dependent. In future we may want to distinguigh the None vs Dependent cases but that does not seem warranted for now.

Fixes #159505

[llvmbot]

@llvm/pr-subscribers-clang

Author: Oliver Hunt (ojhunt)

Changes

We can't give a correct answer for dependent types, so for now just report no ptrauth involves if the type being queried is dependent. In future we may want to distinguigh the None vs Dependent cases but that does not seem warranted for now.

---

Full diff: https://github.com/llvm/llvm-project/pull/159859.diff

2 Files Affected:

• (modified) clang/lib/AST/ASTContext.cpp (+3)
• (modified) clang/test/SemaCXX/ptrauth-type-traits.cpp (+37-1)

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index e49ff9080571e..97c59b2ceec2f 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1707,6 +1707,9 @@ ASTContext::findPointerAuthContent(QualType T) const {
   assert(isPointerAuthenticationAvailable());
 
   T = T.getCanonicalType();
+  if (T->isDependentType())
+    return PointerAuthContent::None;
+
   if (T.hasAddressDiscriminatedPointerAuth())
     return PointerAuthContent::AddressDiscriminatedData;
   const RecordDecl *RD = T->getAsRecordDecl();
diff --git a/clang/test/SemaCXX/ptrauth-type-traits.cpp b/clang/test/SemaCXX/ptrauth-type-traits.cpp
index aefbd63fa1677..a81ef1cce25b6 100644
--- a/clang/test/SemaCXX/ptrauth-type-traits.cpp
+++ b/clang/test/SemaCXX/ptrauth-type-traits.cpp
@@ -8,13 +8,14 @@
 // expected-no-diagnostics
 
 #ifdef __PTRAUTH__
-
+#define PTRAUTH_ENABLED 1
 #define NonAddressDiscriminatedVTablePtrAttr \
   [[clang::ptrauth_vtable_pointer(process_independent, no_address_discrimination, no_extra_discrimination)]]
 #define AddressDiscriminatedVTablePtrAttr \
   [[clang::ptrauth_vtable_pointer(process_independent, address_discrimination, no_extra_discrimination)]]
 #define ADDR_DISC_ENABLED true
 #else
+#define PTRAUTH_ENABLED 0
 #define NonAddressDiscriminatedVTablePtrAttr
 #define AddressDiscriminatedVTablePtrAttr
 #define ADDR_DISC_ENABLED false
@@ -399,3 +400,38 @@ static_assert(!ASSIGNABLE_WRAPPER(RelocatableAddressDiscriminatedPrimaryBase));
 static_assert(!ASSIGNABLE_WRAPPER(RelocatableAddressDiscriminatedSecondaryBase));
 static_assert(!ASSIGNABLE_WRAPPER(EmbdeddedAddressDiscriminatedPolymorphicClass));
 static_assert(!ASSIGNABLE_WRAPPER(RelocatableEmbdeddedAddressDiscriminatedPolymorphicClass));
+
+namespace GH159505 {
+  class A {
+    virtual void f();
+  };
+
+  template <int N> struct B {
+    class C : A {
+      A a[N];
+    } d;
+  };
+
+  template <int N> struct C {
+    void *__ptrauth(1,1,1) ptr[N];
+    static_assert(PTRAUTH_ENABLED != __is_trivially_copyable(decltype(ptr)));
+  };
+  template <class T, bool isPtrauth> struct D {
+    T ptr;
+    static_assert(isPtrauth != __is_trivially_copyable(decltype(ptr)));
+  };
+
+
+  template <class T> using Ptr = T * __ptrauth(1,1,1);
+  template <class T> void test() {
+    static_assert(PTRAUTH_ENABLED != __is_trivially_copyable(Ptr<T>));
+  }
+
+  auto f = test<int>;
+  static_assert(!__is_trivially_copyable(B<1>));
+  static_assert(PTRAUTH_ENABLED != __is_trivially_copyable(C<1>));
+
+
+  D<void *, false> d_void;
+  D<void * __ptrauth(1,1,1), PTRAUTH_ENABLED> d_void_ptrauth;
+}

[porglezomp]

This also needs to be cherry-picked to release/21.x

[ojhunt]

/cherry-pick f6c711b

[llvmbot]

/pull-request #161288