[clang] d02786e - [Sema] Handle AttributedType in template deduction with derived-to-base conversions (#134361)

[via cfe-commits]

Author: Ilya Biryukov
Date: 2025-04-04T14:23:55+02:00
New Revision: d02786e7785ffa8c0aae4d89e9f6391bb4645500

URL: https://github.com/llvm/llvm-project/commit/d02786e7785ffa8c0aae4d89e9f6391bb4645500
DIFF: https://github.com/llvm/llvm-project/commit/d02786e7785ffa8c0aae4d89e9f6391bb4645500.diff

LOG: [Sema] Handle AttributedType in template deduction with derived-to-base conversions (#134361)

Fix #134356.

We accidentally skipped checking derived-to-base conversions because
deduction did not strip sugar in the relevant code. This caused
deduction failures when a parameter type had an attribute.

Added: 
    clang/test/Sema/nullability-and-template-deduction.cpp

Modified: 
    clang/lib/Sema/SemaTemplateDeduction.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
index ab6e18aee7206..170b9f05002b1 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -4447,7 +4447,7 @@ static bool AdjustFunctionParmAndArgTypesForDeduction(
   //       transformed A can be a pointer to a derived class pointed to by
   //       the deduced A.
   if (isSimpleTemplateIdType(ParamType) ||
-      (isa<PointerType>(ParamType) &&
+      (ParamType->getAs<PointerType>() &&
        isSimpleTemplateIdType(
            ParamType->castAs<PointerType>()->getPointeeType())))
     TDF |= TDF_DerivedClass;

diff  --git a/clang/test/Sema/nullability-and-template-deduction.cpp b/clang/test/Sema/nullability-and-template-deduction.cpp
new file mode 100644
index 0000000000000..3ea6d38d26b69
--- /dev/null
+++ b/clang/test/Sema/nullability-and-template-deduction.cpp
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -fsyntax-only %s -verify
+// expected-no-diagnostics
+
+template <class T> struct Base {};
+template <class T> struct Derived : Base<T> {};
+
+template <class T> void foo(Base<T> *_Nonnull);
+
+template <class T> void bar(Base<T> *);
+
+
+void test() {
+    Derived<int> d;
+    foo(&d);
+    bar(&d);
+}