https://github.com/Serosh-commits created https://github.com/llvm/llvm-project/pull/233138
When an invalid template parameter list is encountered while partially ordering template template arguments, finishing deduction can produce `NonDeducedMismatch` so treating this as a failed match instead of asserting that the template-template parameter is invalid Fixes #227649 From cb0947634c41a24b761863b47be410467ef8e6c4 Mon Sep 17 00:00:00 2001 From: Serosh-commits <[email protected]> Date: Sun, 18 Oct 2026 02:59:23 +0530 Subject: [PATCH] [clang] Handle invalid template template arguments in partial ordering --- clang/lib/Sema/SemaTemplateDeduction.cpp | 6 ++---- clang/test/SemaTemplate/gh227649.cpp | 6 ++++++ 2 files changed, 8 insertions(+), 4 deletions(-) create mode 100644 clang/test/SemaTemplate/gh227649.cpp diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp index 1544fd56b82ae2..651114329d4e9e 100644 --- a/clang/lib/Sema/SemaTemplateDeduction.cpp +++ b/clang/lib/Sema/SemaTemplateDeduction.cpp @@ -6609,11 +6609,9 @@ bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( case TemplateDeductionResult::Success: return true; - // It doesn't seem possible to get a non-deduced mismatch when partial - // ordering TTPs, except with an invalid template parameter list which has - // a parameter after a pack. + // An invalid template parameter list can produce a non-deduced mismatch + // while finishing the deduction. case TemplateDeductionResult::NonDeducedMismatch: - assert(PArg->isInvalidDecl() && "Unexpected NonDeducedMismatch"); return false; // Substitution failures should have already been diagnosed. diff --git a/clang/test/SemaTemplate/gh227649.cpp b/clang/test/SemaTemplate/gh227649.cpp new file mode 100644 index 00000000000000..02784971cb6907 --- /dev/null +++ b/clang/test/SemaTemplate/gh227649.cpp @@ -0,0 +1,6 @@ +// RUN: %clang_cc1 -fsyntax-only %s 2>&1 | FileCheck %s +// CHECK: error: use of undeclared identifier 'foo' + +template <template <decltype(foo())> typename> struct S {}; +template <int &p> struct P; +S<P> s; _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
