-Wc++98-compat: warn if a SFINAE substitution in C++11 suppresses an access
control diagnostic.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@142463 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/Diagnostic.h b/include/clang/Basic/Diagnostic.h
index ae0f6ea..7dde271 100644
--- a/include/clang/Basic/Diagnostic.h
+++ b/include/clang/Basic/Diagnostic.h
@@ -740,6 +740,11 @@
assert(isActive() && "DiagnosticsEngine is inactive");
return DiagObj->CurDiagID;
}
+
+ /// \brief Retrieve the active diagnostic's location.
+ ///
+ /// \pre \c isActive()
+ SourceLocation getLocation() const { return DiagObj->CurDiagLoc; }
/// \brief Clear out the current diagnostic.
void Clear() { DiagObj = 0; }
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 8d8a888..5c4ecc8 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -808,6 +808,9 @@
" inheritance here">;
def note_access_protected_restricted : Note<
"object type %select{|%1 }0must derive from context type %2">;
+def warn_cxx98_compat_sfinae_access_control : Warning<
+ "substitution failure due to access control is incompatible with C++98">,
+ InGroup<CXX98Compat>, DefaultIgnore, NoSFINAE;
// C++ name lookup
def err_incomplete_nested_name_spec : Error<
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index 4a9d8a5..8346cc4 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -625,18 +625,9 @@
if (llvm::Optional<TemplateDeductionInfo*> Info = SemaRef.isSFINAEContext()) {
switch (DiagnosticIDs::getDiagnosticSFINAEResponse(getDiagID())) {
case DiagnosticIDs::SFINAE_Report:
- // Fall through; we'll report the diagnostic below.
+ // We'll report the diagnostic below.
break;
- case DiagnosticIDs::SFINAE_AccessControl:
- // Per C++ Core Issue 1170, access control is part of SFINAE.
- // Additionally, the AccessCheckingSFINAE flag can be used to temporary
- // make access control a part of SFINAE for the purposes of checking
- // type traits.
- if (!SemaRef.AccessCheckingSFINAE &&
- !SemaRef.getLangOptions().CPlusPlus0x)
- break;
-
case DiagnosticIDs::SFINAE_SubstitutionFailure:
// Count this failure so that we know that template argument deduction
// has failed.
@@ -646,6 +637,33 @@
Clear();
return;
+ case DiagnosticIDs::SFINAE_AccessControl: {
+ // Per C++ Core Issue 1170, access control is part of SFINAE.
+ // Additionally, the AccessCheckingSFINAE flag can be used to temporary
+ // make access control a part of SFINAE for the purposes of checking
+ // type traits.
+ if (!SemaRef.AccessCheckingSFINAE &&
+ !SemaRef.getLangOptions().CPlusPlus0x)
+ break;
+
+ SourceLocation Loc = getLocation();
+
+ // Suppress this diagnostic.
+ ++SemaRef.NumSFINAEErrors;
+ SemaRef.Diags.setLastDiagnosticIgnored();
+ SemaRef.Diags.Clear();
+ Clear();
+
+ // Now the diagnostic state is clear, produce a C++98 compatibility
+ // warning.
+ SemaRef.Diag(Loc, diag::warn_cxx98_compat_sfinae_access_control);
+
+ // The last diagnostic which Sema produced was ignored. Suppress any
+ // notes attached to it.
+ SemaRef.Diags.setLastDiagnosticIgnored();
+ return;
+ }
+
case DiagnosticIDs::SFINAE_Suppress:
// Make a copy of this suppressed diagnostic and store it with the
// template-deduction information;
diff --git a/test/SemaCXX/cxx98-compat.cpp b/test/SemaCXX/cxx98-compat.cpp
index 84dc87a..8da54f0 100644
--- a/test/SemaCXX/cxx98-compat.cpp
+++ b/test/SemaCXX/cxx98-compat.cpp
@@ -170,3 +170,12 @@
};
int n = {}; // expected-warning {{scalar initialized from empty initializer list is incompatible with C++98}}
+
+class PrivateMember {
+ struct ImPrivate {};
+};
+template<typename T> typename T::ImPrivate SFINAEAccessControl(T t) { // expected-warning {{substitution failure due to access control is incompatible with C++98}} expected-note {{while substituting deduced template arguments into function template 'SFINAEAccessControl' [with T = PrivateMember]}}
+ return typename T::ImPrivate();
+}
+int SFINAEAccessControl(...) { return 0; }
+int CheckSFINAEAccessControl = SFINAEAccessControl(PrivateMember());
