[clang] [clang][Sema] GH58548 (PR #80395)

[Younan Zhang via cfe-commits]

https://github.com/zyn0217 created https://github.com/llvm/llvm-project/pull/80395

Draft for triggering the libc++ CI.

>From 24a8251aab9a1a03953412ae47508d039d926212 Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Fri, 2 Feb 2024 15:24:13 +0800
Subject: [PATCH] [clang][Sema] Fix GH58548

---
 clang/docs/ReleaseNotes.rst                   |  3 +++
 clang/lib/Sema/SemaOverload.cpp               |  3 ++-
 .../SemaTemplate/concepts-recovery-expr.cpp   | 27 +++++++++++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 37f2423441a30..f4c5c3421f2e8 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -183,6 +183,9 @@ Bug Fixes to C++ Support
 - Fix for crash when using a erroneous type in a return statement.
   Fixes (`#63244 <https://github.com/llvm/llvm-project/issues/63244>`_)
   and (`#79745 <https://github.com/llvm/llvm-project/issues/79745>`_)
+- Fixed an out-of-bounds error caused by building a recovery expression for ill-formed
+  function calls while substituting into constraints.
+  (`https://github.com/llvm/llvm-project/issues/58548`_)
 - Fix incorrect code generation caused by the object argument of ``static operator()`` and ``static operator[]`` calls not being evaluated.
   Fixes (`#67976 <https://github.com/llvm/llvm-project/issues/67976>`_)
 
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 940bcccb9e261..6a04d68b4f041 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -7623,7 +7623,8 @@ void Sema::AddTemplateOverloadCandidate(
   //   functions. In such a case, the candidate functions generated from each
   //   function template are combined with the set of non-template candidate
   //   functions.
-  TemplateDeductionInfo Info(CandidateSet.getLocation());
+  TemplateDeductionInfo Info(CandidateSet.getLocation(),
+                             FunctionTemplate->getTemplateDepth());
   FunctionDecl *Specialization = nullptr;
   ConversionSequenceList Conversions;
   if (TemplateDeductionResult Result = DeduceTemplateArguments(
diff --git a/clang/test/SemaTemplate/concepts-recovery-expr.cpp b/clang/test/SemaTemplate/concepts-recovery-expr.cpp
index 2f9d432ebac0e..b338f3bc271bf 100644
--- a/clang/test/SemaTemplate/concepts-recovery-expr.cpp
+++ b/clang/test/SemaTemplate/concepts-recovery-expr.cpp
@@ -180,3 +180,30 @@ void StaticMemOVCUse() {
   // expected-note@#SMEMOVC3 {{candidate template ignored: constraints not satisfied}}
   // expected-note@#SMEMOVC3REQ{{because substituted constraint expression is ill-formed: constraint depends on a previously diagnosed expression}}
 }
+
+namespace GH58548 {
+
+template <class, class> struct formatter; // #primary-template
+template <class, class> struct basic_format_context {};
+
+template <typename CharType>
+concept has_format_function =
+    format(basic_format_context<CharType, CharType>());
+
+template <typename ValueType, typename CharType>
+  requires has_format_function<CharType>
+struct formatter<ValueType, CharType> {
+  template <typename OutputIt>
+  CharType format(basic_format_context<OutputIt, CharType>);
+};
+
+template <class Ctx> int handle_replacement_field(Ctx arg) {
+  formatter<decltype(arg), int> ctx; // expected-error {{implicit instantiation of undefined template}}
+  return 0;
+}
+
+int x = handle_replacement_field(0);
+// expected-note at -1 {{template specialization 'GH58548::handle_replacement_field<int>' requested here}}
+// expected-note@#primary-template {{is declared here}}
+
+} // GH58548