[clang] ce51248 - [Clang] Fix an incorrect assertion in `Sema::CheckAddressOfOperand` (#159314)

[via cfe-commits]

Author: Corentin Jabot
Date: 2025-09-17T14:38:08+02:00
New Revision: ce5124856e019792783de9630d0c5a1f0aaf2d9d

URL: https://github.com/llvm/llvm-project/commit/ce5124856e019792783de9630d0c5a1f0aaf2d9d
DIFF: https://github.com/llvm/llvm-project/commit/ce5124856e019792783de9630d0c5a1f0aaf2d9d.diff

LOG: [Clang] Fix an incorrect assertion in `Sema::CheckAddressOfOperand` (#159314)

Not all non-type template arguments are modeled as
NonTypeTemplateParmDecl.

Fixes #151531

Added: 
    

Modified: 
    clang/docs/ReleaseNotes.rst
    clang/lib/Sema/SemaExpr.cpp
    clang/test/SemaTemplate/temp_arg_nontype_cxx20.cpp

Removed: 
    


################################################################################
diff  --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 518ed9e0f4b3e..80f4e83a11b70 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -396,6 +396,8 @@ Bug Fixes to C++ Support
   the function type.
 - Fix an assertion failure when a ``constexpr`` variable is only referenced through
   ``__builtin_addressof``, and related issues with builtin arguments. (#GH154034)
+- Fix an assertion failure when taking the address on a non-type template parameter argument of
+  object type. (#GH151531)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^

diff  --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 73b16ae09e922..03def26fe53bd 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -14725,8 +14725,9 @@ QualType Sema::CheckAddressOfOperand(ExprResult &OrigOp, SourceLocation OpLoc) {
           return MPTy;
         }
       }
-    } else if (!isa<FunctionDecl, NonTypeTemplateParmDecl, BindingDecl,
-                    MSGuidDecl, UnnamedGlobalConstantDecl>(dcl))
+    } else if (!isa<FunctionDecl, TemplateParamObjectDecl,
+                    NonTypeTemplateParmDecl, BindingDecl, MSGuidDecl,
+                    UnnamedGlobalConstantDecl>(dcl))
       llvm_unreachable("Unknown/unexpected decl type");
   }
 

diff  --git a/clang/test/SemaTemplate/temp_arg_nontype_cxx20.cpp b/clang/test/SemaTemplate/temp_arg_nontype_cxx20.cpp
index 56ceb7af4ccd9..8450ff037e184 100644
--- a/clang/test/SemaTemplate/temp_arg_nontype_cxx20.cpp
+++ b/clang/test/SemaTemplate/temp_arg_nontype_cxx20.cpp
@@ -371,3 +371,18 @@ namespace ReportedRegression2 {
     fn<str>();
   }
 }
+
+namespace GH151531 {
+struct w {
+    int n;
+};
+
+template <const w *X> void f() { static_assert(X->n == 42); }
+
+template <w X> void g() { f<&X>(); }
+
+void test() {
+    constexpr w X = {42};
+    g<X>();
+}
+}